Science.gov

Sample records for flow improving additives

  1. High Flow Addition Curing Polyimides

    NASA Technical Reports Server (NTRS)

    Chuang, Kathy C.; Vannucci, Raymond D.; Ansari, Irfan; Cerny, Lawrence L.; Scheiman, Daniel A.

    1994-01-01

    A new series of high flow PMR-type addition curing polyimides was developed, which employed the substitution of 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl (BTDB) for p-phenylenediamine (p -PDA) in a PMR-IL formulation. These thermoset polyimides, designated as 12F resins, were prepared from BTDB and the dimethyl ester of 4,4'- (hexafluo- roisopropylidene) -diphthalic acid (HFDE) with either nadic ester (NE) or p-aminostyrene (PAS) as the endcaps for addition curing. The 12F prepolymers displayed lower melting temperatures in DSC analysis, and higher melt flow in rheological studies than the cor- responding PMR-11 polyimides. Long-term isothermal aging studies showed that BTDB- based 12F resins exhibited comparable thermo-oxidative stability to P-PDA based PMR-11 polyimides. The noncoplanar 2- and 2'-disubstituted biphenyldiamine (BTDB) not only lowered the melt viscosities of 12F prepolymers, but also retained reasonable thermal sta- bility of the cured resins. The 12F polyimide resin with p-aminostyrene endcaps showed the best promise for long-term, high-temperature application at 343 C (650 F).

  2. Novel additives to retard permeable flow

    SciTech Connect

    Golombok, Michael; Crane, Carel; Ineke, Erik; Welling, Marco; Harris, Jon

    2008-09-15

    Low concentrations of surfactant and cosolute in water, can selectively retard permeable flow in high permeability rocks compared to low permeability ones. This represents a way forward for more efficient areal sweep efficiency when water flooding a reservoir during improved oil recovery. (author)

  3. Improving emergency department patient flow.

    PubMed

    Jarvis, Paul Richard Edwin

    2016-06-01

    Emergency departments (ED) face significant challenges in delivering high quality and timely patient care on an ever-present background of increasing patient numbers and limited hospital resources. A mismatch between patient demand and the ED's capacity to deliver care often leads to poor patient flow and departmental crowding. These are associated with reduction in the quality of the care delivered and poor patient outcomes. A literature review was performed to identify evidence-based strategies to reduce the amount of time patients spend in the ED in order to improve patient flow and reduce crowding in the ED. The use of doctor triage, rapid assessment, streaming and the co-location of a primary care clinician in the ED have all been shown to improve patient flow. In addition, when used effectively point of care testing has been shown to reduce patient time in the ED. Patient flow and departmental crowding can be improved by implementing new patterns of working and introducing new technologies such as point of care testing in the ED.

  4. Improving emergency department patient flow

    PubMed Central

    Jarvis, Paul Richard Edwin

    2016-01-01

    Emergency departments (ED) face significant challenges in delivering high quality and timely patient care on an ever-present background of increasing patient numbers and limited hospital resources. A mismatch between patient demand and the ED’s capacity to deliver care often leads to poor patient flow and departmental crowding. These are associated with reduction in the quality of the care delivered and poor patient outcomes. A literature review was performed to identify evidence-based strategies to reduce the amount of time patients spend in the ED in order to improve patient flow and reduce crowding in the ED. The use of doctor triage, rapid assessment, streaming and the co-location of a primary care clinician in the ED have all been shown to improve patient flow. In addition, when used effectively point of care testing has been shown to reduce patient time in the ED. Patient flow and departmental crowding can be improved by implementing new patterns of working and introducing new technologies such as point of care testing in the ED. PMID:27752619

  5. Polymer additives improve cementing in salt formations

    SciTech Connect

    Rae, P. )

    1988-12-05

    Recently, new anionic aromatic polymers (AAP's) have been identified that simultaneously impart to salt-rich cement slurries improved fluid-loss control and exceptional rheological properties. At the same time, these materials do not significantly extend the slurry-thickening time or impair the compressive strength development of the cement. Thus, the casing strings are protected in plastic zones very soon after completing the cement job. The cementing of wells penetrating massive salt formations has posed a number of problems over the years. Contributing to the problem was the fact that some cements displayed poor characteristics in saline environments, and that conventional additives were of limited use in these systems. Other additives, designed for salt water, were found to provide characteristics far from the optimum, while at the same time causing detrimental effects on other slurry properties, notably rheology, thickening time, and early compressive strength. In several areas, the presence of salt domes and massive evaporite sequences cause problems in the drilling, completion, and long-term production of oil and gas wells that penetrate these zones.

  6. F-76 Lubricity Improver Additive Evaluation

    DTIC Science & Technology

    2013-09-16

    steel 8-inch extender tube is attached to the large bung of the drum and a stainless steel, air driven pump is placed into the extender tube. The...drum pump outlet line is then attached onto the 90-degree stainless steel fitting on the small bung of the drum and the additized referee fuel is

  7. Mitigating cold flow problems of biodiesel: Strategies with additives

    NASA Astrophysics Data System (ADS)

    Mohanan, Athira

    The present thesis explores the cold flow properties of biodiesel and the effect of vegetable oil derived compounds on the crystallization path as well as the mechanisms at play at different stages and length scales. Model systems including triacylglycerol (TAG) oils and their derivatives, and a polymer were tested with biodiesel. The goal was to acquire the fundamental knowledge that would help design cold flow improver (CFI) additives that would address effectively and simultaneously the flow problems of biodiesel, particularly the cloud point (CP) and pour point (PP). The compounds were revealed to be fundamentally vegetable oil crystallization modifiers (VOCM) and the polymer was confirmed to be a pour point depressant (PPD). The results obtained with the VOCMs indicate that two cis-unsaturated moieties combined with a trans-/saturated fatty acid is a critical structural architecture for depressing the crystallization onset by a mechanism wherein while the straight chain promotes a first packing with the linear saturated FAMEs, the kinked moieties prevent further crystallization. The study of model binary systems made of a VOCM and a saturated FAME with DSC, XRD and PLM provided a complete phase diagram including the thermal transformation lines, crystal structure and microstructure that impact the phase composition along the different crystallization stages, and elicited the competing effects of molecular mass, chain length mismatch and isomerism. The liquid-solid boundary is discussed in light of a simple thermodynamic model based on the Hildebrand equation and pair interactions. In order to test for synergies, the PP and CP of a biodiesel (Soy1500) supplemented with several VOCM and PLMA binary cocktails were measured using a specially designed method inspired by ASTM standards. The results were impressive, the combination of additives depressed CP and PP better than any single additive. The PLM and DSC results suggest that the cocktail additives are most

  8. Electrolyte additive for improved battery performance

    DOEpatents

    Bellows, Richard J.; Kantner, Edward

    1989-04-04

    In one embodiment of the present invention, there is provided an electrochemical cell having a metal bromine couple. The cell includes an electrode structure on which to deposit the metal of the couple and a counterelectrode at which to generate bromine. A microporous membrane separates the electrode and counterelectrode. Importantly, the aqueous electrolyte comprises an aqueous metal bromide solution containing a water soluble bromine complexing agent capable of forming a water immiscible complex with bromine and an additive capable of decreasing the wettability of the microporous separators employed in such cells by such water immiscible bromine complexes.

  9. Difluorocarbene Addition to Alkenes and Alkynes in Continuous Flow.

    PubMed

    Rullière, Pauline; Cyr, Patrick; Charette, André B

    2016-05-06

    The first in-flow difluorocarbene generation and addition to alkenes and alkynes is reported. The application of continuous flow technology allowed for the controlled generation of difluorocarbene from TMSCF3 and a catalytic quantity of NaI. The in situ generated electrophilic carbene reacts smoothly with a broad range of alkenes and alkynes, allowing the synthesis of the corresponding difluorocyclopropanes and difluorocyclopropenes. The reaction is complete within a 10 min residence time at high reaction concentrations. With a production flow rate of 1 mmol/min, continuous flow chemistry enables scale up of this process in a green, atom-economic, and safe manner.

  10. Proper planning improves flow drilling

    SciTech Connect

    Collins, G.J. )

    1994-10-01

    Underbalanced operations reduce formation damage, especially in horizontal wells where zones are exposed to mud for longer time periods. Benefits, risks, well control concerns, equipment and issues associated with these operations are addressed in this paper. Flow drilling raises many concerns, but little has been published on horizontal well control and flow drilling operations. This article covers planning considerations for flow drilling, but does not address horizontal ''overbalanced'' drilling because considerations and equipment are the same as in vertical overbalanced drilling and many references address that subject. The difference in well control between vertical and horizontal overbalanced drilling is fluid influx behavior and how that behavior affects kill operations.

  11. Improved Techniques for Targeting Additional Observations to Improve Forecast Skill

    DTIC Science & Technology

    2016-06-07

    T oulouse F rance Grant Num ber: N00014{99{1{0755 LONG-TERM GOAL This project aims to improv e ensemble forecast and adaptive observ ation tec...be studied. It will be assessed whether the assimilation system can be geared to more readily accept adaptive observations made in currently data

  12. Rinse trough with improved flow

    DOEpatents

    O`Hern, T.J.; Grasser, T.W.

    1998-08-11

    Novel rinse troughs accomplish thorough uniform rinsing. The troughs are suitable for one or more essentially planar objects having substantially the same shape. The troughs ensure that each surface is rinsed uniformly. The new troughs provide uniform rinse fluid flow over the objects` surfaces to accomplish a more thorough rinse than prior art troughs. 5 figs.

  13. Rinse trough with improved flow

    DOEpatents

    O'Hern, Timothy J.; Grasser, Thomas W.

    1998-01-01

    Novel rinse troughs accomplish thorough uniform rinsing. The troughs are suitable for one or more essentially planar objects having substantially the same shape. The troughs ensure that each surface is rinsed uniformly. The new troughs provide uniform rinse fluid flow over the objects' surfaces to accomplish a more thorough rinse than prior art troughs.

  14. Use of a static eliminator to improve powder flow.

    PubMed

    Pingali, Kalyana C; Hammond, Stephen V; Muzzio, Fernando J; Shinbrot, Troy

    2009-03-18

    Glidants and lubricants have long been used to improve the flow and processing of pharmaceutical and other powder blends. In this letter, we find that similar improvements can be attained, without additives, by using a simple static eliminator. These results indicate, first, that electrostatic effects on powder blends may be a significant cause of powder aggregation and flow instabilities, and second, that common additives such as magnesium stearate, colloidal silica, and talc may have as their chief effect the reduction of static. This suggests both that intelligent placement of static eliminators can eliminate the need for some of these additives and that judicious engineering of ionic and cationic additives may be effective in improving flow of "clingy" materials.

  15. Improved Panel-Method/Potential-Flow Code

    NASA Technical Reports Server (NTRS)

    Ashby, Dale L.

    1991-01-01

    Panel code PMARC (Panel Method Ames Research Center) numerically simulates flow field around complex three-dimensional bodies, such as complete aircraft models. Based on potential-flow theory. Written in FORTRAN 77, with exception of namelist extension used for input. Structure facilitates addition of new features to code and tailoring of code to specific problems and computer hardware constraints.

  16. Improved Flow-Controlling Vortex Generator

    NASA Technical Reports Server (NTRS)

    Collins, Earl R., Jr.; Marner, Wilbur J.; Rohatgi, Naresh K.

    1989-01-01

    Symmetrical tangential streams control flow of radial primary streams. Vortex generator uses small secondary stream of fluid to control normally-larger primary stream. Improved version of vortex generator described in "Variable Control Port for Fluidic Control Device," (NPO-16603). Secondary, or control, flows entering tangentially through diametrically opposite ports set up swirling motion restraining primary flow. Pressure of secondary fluid in relation to primary fluid controlling factor. Like valve, vortex generator varies rate of flow of primary fluid from maximum value down to zero. When properly designed, requires low pressure differential between primary and secondary streams and expends relatively small amount of secondary fluid.

  17. Improvement of GRCop-84 Through the Addition of Zirconium

    NASA Technical Reports Server (NTRS)

    Ellis, David L.; Lerch, Bradley A.

    2012-01-01

    GRCop-84 (Cu-8 at.% Cr-4 at.% Nb) has excellent strength, creep resistance, low cycle fatigue (LCF) life and stability at elevated temperatures. It suffers in comparison to many commercially available precipitation-strengthened alloys below 500 C (932 F). It was observed that the addition of Zr consistently improved the mechanical properties of Cu-based alloys especially below 500 C. In an effort to improve the low temperature properties of GRCop-84, 0.35 wt.% Zr was added to the alloy. Limited tensile, creep, and LCF testing was conducted to determine if improvements occur. The results showed some dramatic increases in the tensile and creep properties at the conditions tested with the probability of additional improvements being possible through cold working. LCF testing at room temperature did not show an improvement, but improvements might occur at elevated temperatures.

  18. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  19. Improving Ecological Response Monitoring of Environmental Flows

    NASA Astrophysics Data System (ADS)

    King, Alison J.; Gawne, Ben; Beesley, Leah; Koehn, John D.; Nielsen, Daryl L.; Price, Amina

    2015-05-01

    Environmental flows are now an important restoration technique in flow-degraded rivers, and with the increasing public scrutiny of their effectiveness and value, the importance of undertaking scientifically robust monitoring is now even more critical. Many existing environmental flow monitoring programs have poorly defined objectives, nonjustified indicator choices, weak experimental designs, poor statistical strength, and often focus on outcomes from a single event. These negative attributes make them difficult to learn from. We provide practical recommendations that aim to improve the performance, scientific robustness, and defensibility of environmental flow monitoring programs. We draw on the literature and knowledge gained from working with stakeholders and managers to design, implement, and monitor a range of environmental flow types. We recommend that (1) environmental flow monitoring programs should be implemented within an adaptive management framework; (2) objectives of environmental flow programs should be well defined, attainable, and based on an agreed conceptual understanding of the system; (3) program and intervention targets should be attainable, measurable, and inform program objectives; (4) intervention monitoring programs should improve our understanding of flow-ecological responses and related conceptual models; (5) indicator selection should be based on conceptual models, objectives, and prioritization approaches; (6) appropriate monitoring designs and statistical tools should be used to measure and determine ecological response; (7) responses should be measured within timeframes that are relevant to the indicator(s); (8) watering events should be treated as replicates of a larger experiment; (9) environmental flow outcomes should be reported using a standard suite of metadata. Incorporating these attributes into future monitoring programs should ensure their outcomes are transferable and measured with high scientific credibility.

  20. Improving ecological response monitoring of environmental flows.

    PubMed

    King, Alison J; Gawne, Ben; Beesley, Leah; Koehn, John D; Nielsen, Daryl L; Price, Amina

    2015-05-01

    Environmental flows are now an important restoration technique in flow-degraded rivers, and with the increasing public scrutiny of their effectiveness and value, the importance of undertaking scientifically robust monitoring is now even more critical. Many existing environmental flow monitoring programs have poorly defined objectives, nonjustified indicator choices, weak experimental designs, poor statistical strength, and often focus on outcomes from a single event. These negative attributes make them difficult to learn from. We provide practical recommendations that aim to improve the performance, scientific robustness, and defensibility of environmental flow monitoring programs. We draw on the literature and knowledge gained from working with stakeholders and managers to design, implement, and monitor a range of environmental flow types. We recommend that (1) environmental flow monitoring programs should be implemented within an adaptive management framework; (2) objectives of environmental flow programs should be well defined, attainable, and based on an agreed conceptual understanding of the system; (3) program and intervention targets should be attainable, measurable, and inform program objectives; (4) intervention monitoring programs should improve our understanding of flow-ecological responses and related conceptual models; (5) indicator selection should be based on conceptual models, objectives, and prioritization approaches; (6) appropriate monitoring designs and statistical tools should be used to measure and determine ecological response; (7) responses should be measured within timeframes that are relevant to the indicator(s); (8) watering events should be treated as replicates of a larger experiment; (9) environmental flow outcomes should be reported using a standard suite of metadata. Incorporating these attributes into future monitoring programs should ensure their outcomes are transferable and measured with high scientific credibility.

  1. The improvement of rechargeable lithium battery electrolyte performance with additives

    NASA Technical Reports Server (NTRS)

    Dominey, L. A.; Goldman, J. L.

    1990-01-01

    The deliberate introduction of additives like 2-methylfuran (2-MeF) is known to improve Li cycleability in cyclic ether electrolytes. The authors found that the proclivity of 2-MeF to polymerize in the bulk electrolyte or on a TiS2 cathode was inhibited by the addition of reduced oxygen species, such as O2- and OH-. Additionally, the polymerization of tetrahydrofuran and dioxolane and the destructive processes initiated by AsF6- decomposition to AsF5 and AsF3 were inhibited by the introduction of reduced oxygen species, particularly OH- at the 10-ppm to 100-ppm level.

  2. Improved modeling techniques for turbomachinery flow fields

    SciTech Connect

    Lakshminarayana, B.; Fagan, J.R. Jr.

    1995-10-01

    This program has the objective of developing an improved methodology for modeling turbomachinery flow fields, including the prediction of losses and efficiency. Specifically, the program addresses the treatment of the mixing stress tensor terms attributed to deterministic flow field mechanisms required in steady-state Computational Fluid Dynamic (CFD) models for turbo-machinery flow fields. These mixing stress tensors arise due to spatial and temporal fluctuations (in an absolute frame of reference) caused by rotor-stator interaction due to various blade rows and by blade-to-blade variation of flow properties. These tasks include the acquisition of previously unavailable experimental data in a high-speed turbomachinery environment, the use of advanced techniques to analyze the data, and the development of a methodology to treat the deterministic component of the mixing stress tensor. Penn State will lead the effort to make direct measurements of the momentum and thermal mixing stress tensors in high-speed multistage compressor flow field in the turbomachinery laboratory at Penn State. They will also process the data by both conventional and conditional spectrum analysis to derive momentum and thermal mixing stress tensors due to blade-to-blade periodic and aperiodic components, revolution periodic and aperiodic components arising from various blade rows and non-deterministic (which includes random components) correlations. The modeling results from this program will be publicly available and generally applicable to steady-state Navier-Stokes solvers used for turbomachinery component (compressor or turbine) flow field predictions. These models will lead to improved methodology, including loss and efficiency prediction, for the design of high-efficiency turbomachinery and drastically reduce the time required for the design and development cycle of turbomachinery.

  3. Improvement of modal scaling factors using mass additive technique

    NASA Technical Reports Server (NTRS)

    Zhang, Qiang; Allemang, Randall J.; Wei, Max L.; Brown, David L.

    1987-01-01

    A general investigation into the improvement of modal scaling factors of an experimental modal model using additive technique is discussed. Data base required by the proposed method consists of an experimental modal model (a set of complex eigenvalues and eigenvectors) of the original structure and a corresponding set of complex eigenvalues of the mass-added structure. Three analytical methods,i.e., first order and second order perturbation methods, and local eigenvalue modification technique, are proposed to predict the improved modal scaling factors. Difficulties encountered in scaling closely spaced modes are discussed. Methods to compute the necessary rotational modal vectors at the mass additive points are also proposed to increase the accuracy of the analytical prediction.

  4. Efficient Improvement of Silage Additives by Using Genetic Algorithms

    PubMed Central

    Davies, Zoe S.; Gilbert, Richard J.; Merry, Roger J.; Kell, Douglas B.; Theodorou, Michael K.; Griffith, Gareth W.

    2000-01-01

    The enormous variety of substances which may be added to forage in order to manipulate and improve the ensilage process presents an empirical, combinatorial optimization problem of great complexity. To investigate the utility of genetic algorithms for designing effective silage additive combinations, a series of small-scale proof of principle silage experiments were performed with fresh ryegrass. Having established that significant biochemical changes occur over an ensilage period as short as 2 days, we performed a series of experiments in which we used 50 silage additive combinations (prepared by using eight bacterial and other additives, each of which was added at six different levels, including zero [i.e., no additive]). The decrease in pH, the increase in lactate concentration, and the free amino acid concentration were measured after 2 days and used to calculate a “fitness” value that indicated the quality of the silage (compared to a control silage made without additives). This analysis also included a “cost” element to account for different total additive levels. In the initial experiment additive levels were selected randomly, but subsequently a genetic algorithm program was used to suggest new additive combinations based on the fitness values determined in the preceding experiments. The result was very efficient selection for silages in which large decreases in pH and high levels of lactate occurred along with low levels of free amino acids. During the series of five experiments, each of which comprised 50 treatments, there was a steady increase in the amount of lactate that accumulated; the best treatment combination was that used in the last experiment, which produced 4.6 times more lactate than the untreated silage. The additive combinations that were found to yield the highest fitness values in the final (fifth) experiment were assessed to determine a range of biochemical and microbiological quality parameters during full-term silage

  5. Efficient improvement of silage additives by using genetic algorithms.

    PubMed

    Davies, Z S; Gilbert, R J; Merry, R J; Kell, D B; Theodorou, M K; Griffith, G W

    2000-04-01

    The enormous variety of substances which may be added to forage in order to manipulate and improve the ensilage process presents an empirical, combinatorial optimization problem of great complexity. To investigate the utility of genetic algorithms for designing effective silage additive combinations, a series of small-scale proof of principle silage experiments were performed with fresh ryegrass. Having established that significant biochemical changes occur over an ensilage period as short as 2 days, we performed a series of experiments in which we used 50 silage additive combinations (prepared by using eight bacterial and other additives, each of which was added at six different levels, including zero [i.e. , no additive]). The decrease in pH, the increase in lactate concentration, and the free amino acid concentration were measured after 2 days and used to calculate a "fitness" value that indicated the quality of the silage (compared to a control silage made without additives). This analysis also included a "cost" element to account for different total additive levels. In the initial experiment additive levels were selected randomly, but subsequently a genetic algorithm program was used to suggest new additive combinations based on the fitness values determined in the preceding experiments. The result was very efficient selection for silages in which large decreases in pH and high levels of lactate occurred along with low levels of free amino acids. During the series of five experiments, each of which comprised 50 treatments, there was a steady increase in the amount of lactate that accumulated; the best treatment combination was that used in the last experiment, which produced 4.6 times more lactate than the untreated silage. The additive combinations that were found to yield the highest fitness values in the final (fifth) experiment were assessed to determine a range of biochemical and microbiological quality parameters during full-term silage fermentation. We

  6. The Addition of Graphene to Polymer Coatings for Improved Weathering

    DOE PAGES

    Nuraje, Nurxat; Khan, Shifath I.; Misak, Heath; ...

    2013-01-01

    Graphene nanoflakes in different weight percentages were added to polyurethane top coatings, and the coatings were evaluated relative to exposure to two different experimental conditions: one a QUV accelerated weathering cabinet, while the other a corrosion test carried out in a salt spray chamber. After the exposure tests, the surface morphology and chemical structure of the coatings were investigated via atomic force microscopy (AFM) and Fourier transform infrared (FTIR) imaging. Our results show that the addition of graphene does in fact improve the resistance of the coatings against ultraviolet (UV) degradation and corrosion. It is believed that this process willmore » improve the properties of the polyurethane top coating used in many industries against environmental factors.« less

  7. Non toxic additives for improved fabric filter performance

    SciTech Connect

    Bustard, C.J.; Baldrey, K.E.; Ebner, T.G.

    1995-11-01

    The overall objective of this three-phase Small Business innovative Research (SBIR) program funded by the Department of Energy pittsburgh Energy Technology Center (PETC) is to commercialize a technology based upon the use of non-toxic, novel flue gas conditioning agents to improve particulate air toxic control and overall fabric filter performance. The ultimate objective of the Phase II program currently in progress is to demonstrate that the candidate additives are successful at full-scale on flue gas from a coal-fired utility boiler. This paper covers bench-scale field tests conducted during the period February through May, 1995. The bench-scale additives testing was conducted on a flue gas slipstream taken upstream of the existing particulate control device at a utility power plant firing a Texas lignite coal. These tests were preceded by extensive testing with additives in the laboratory using a simulated flue gas stream and re-dispersed flyash from the same power plant. The bench-scale field testing was undertaken to demonstrate the performance with actual flue gas of the bet candidate additives previously identified in the laboratory. Results from the bench-scale tests will be used to establish operating parameters for a larger-scale demonstration on either a single baghouse compartment or a full baghouse at the same site.

  8. Improvement of MEM-deconvolution by an additional constraint

    NASA Astrophysics Data System (ADS)

    Reiter, J.; Pfleiderer, J.

    1986-09-01

    An attempt is made to improve existing versions of the maximum entropy method (MEM) and their understanding. Additional constraints are discussed, especially the T-statistic which can significantly reduce the correlation between residuals and model. An implementation of the T constraint into MEM requires a new numerical algorithm, which is made to work most efficiently on modern vector-processing computers. The entropy functional is derived from simple mathematical assumptions. The new MEM version is tested with radio data of NGC 6946 and optical data from M 87.

  9. Nuclear Fuel Cycle Options Catalog FY15 Improvements and Additions.

    SciTech Connect

    Price, Laura L.; Barela, Amanda Crystal; Schetnan, Richard Reed; Walkow, Walter M.

    2015-11-01

    The United States Department of Energy, Office of Nuclear Energy, Fuel Cycle Technology Program sponsors nuclear fuel cycle research and development. As part of its Fuel Cycle Options campaign, the DOE has established the Nuclear Fuel Cycle Options Catalog. The catalog is intended for use by the Fuel Cycle Technologies Program in planning its research and development activities and disseminating information regarding nuclear energy to interested parties. The purpose of this report is to document the improvements and additions that have been made to the Nuclear Fuel Cycle Options Catalog in the 2015 fiscal year.

  10. Improving properties of Mg with Al–Cu additions

    SciTech Connect

    Rashad, Muhammad; Pan, Fusheng; Asif, Muhammad; Hussain, Shahid; Saleem, Muhammad

    2014-09-15

    The present work reports improvement in tensile properties of the Mg matrix reinforced with micron-sized copper–aluminum particulate hybrids. The Al–Cu particulate hybrids were incorporated into the Mg matrix through powder metallurgy method. The synthesized alloys exhibited homogeneously dispersed Mg{sub 2}Cu particles in the matrix, therefore leading to a 110% increase in yield strength (221 MPa) and a 72% enhancement in ultimate tensile strength (284 MPa) by addition of 1.0 wt.%Al–0.6 wt.%Cu particle hybrids. Optical microscopy, scanning election microscopy, transmission electron microscopy and X-ray diffraction were used to investigate the microstructure and intermetallic phases of the synthesized alloys. - Highlights: • Mg matrix is reinforced with Al–Cu particulate hybrids. • Powder metallurgic method is used to fabricate the alloys. • Tensile strength and ductility were increased simultaneously.

  11. The improvement of the Pluto orbit using additional new data

    NASA Astrophysics Data System (ADS)

    Girdiuk, A.

    2015-08-01

    Observational series of the Pluto dwarf planet have started since 1913. At this moment observations have covered only a third of the Pluto orbit, therefore, the Pluto orbital elements are defined with insufficient accuracy. A growing number of observations leads to the improvement of the accuracy of the orbit determination. The database of the Pluto's observations was expanded with the help of about 350 observations during 1930-1996 obtained at the Pulkovo Observatory, and about 5500 observations (1995-2013) including occultation data from Brazilian colleagues obtained at the European Southern Observatory and the Pico dos Dias Observatory, and the new analyzed 469 historical photographic observations archived at Lowell Observatory. The new cross-platform software ERA-8 has been developed in IAA RAS and has been used for implementation of all mathematical procedures for constructing Pluto orbit. The modern ephemerides (EPM2011, EPM2013, DE430, DE432, INPOP13c) are chosen for comparison of the ephemeris positions: equatorial coordinates and heliocentric distance. The main result of the work - construction of ephemerides EPM2014a is a significant improvement of the Pluto's orbit using additional observations.

  12. ADDITIVE TESTING FOR IMPROVED SULFUR RETENTION: PRELIMINARY REPORT

    SciTech Connect

    Amoroso, J.; Fox, K.

    2011-09-07

    The Savannah River National Laboratory is collaborating with Alfred University to evaluate the potential for additives in borosilicate glass to improve sulfur retention. This preliminary report provides further background on the incorporation of sulfur in glass and outlines the experiments that are being performed by the collaborators. A simulated waste glass composition has been selected for the experimental studies. The first phase of experimental work will evaluate the impacts of BaO, PbO, and V{sub 2}O{sub 5} at concentrations of 1.0, 2.0, and 5.0 wt % on sulfate retention in simulated high level waste borosilicate glass. The second phase of experimental work will evaluate the effects of time at the melt temperature on sulfur retention. The resulting samples will be characterized to determine the amount of sulfur remaining as well as to identify the formation of any crystalline phases. The results will be used to guide the future selection of frits and glass forming chemicals in vitrifying Department of Energy wastes containing high sulfur concentrations.

  13. Improved dental adhesive formulations based on reactive nanogel additives.

    PubMed

    Morães, R R; Garcia, J W; Wilson, N D; Lewis, S H; Barros, M D; Yang, B; Pfeifer, C S; Stansbury, J W

    2012-02-01

    Current challenges in adhesive dentistry include over-hydrophilic bonding formulations, which facilitate water percolation through the hybrid layer and result in unreliable bonded interfaces. This study introduces nanogel-modified adhesives as a way to control the material's hydrophobic character without changing the basic monomer formulation (keeping water-chasing capacity and operatory techniques unaltered). Nanogel additives of varied hydrophobicity were synthesized in solution, rendering 10- to 100-nm-sized particles. A model BisGMA/HEMA solvated adhesive was prepared (control), to which reactive nanogels were added. The increase in adhesive viscosity did not impair solvent removal by air-thinning. The degree of conversion in the adhesive was similar between control and nanogel-modified materials, while the bulk dry and, particularly, the wet mechanical properties were significantly improved through nanogel-based network reinforcement and reduced water solubility. As preliminary validation of this approach, short-term micro-tensile bond strengths to acid-etched and primed dentin were significantly enhanced by nanogel inclusion in the adhesive resins.

  14. Mars-GRAM 2010: Additions and Resulting Improvements

    NASA Technical Reports Server (NTRS)

    Justh, Hilary L.; Burns, K. Lee

    2013-01-01

    factors. The adjustment factors generated by this process had to satisfy the gas law as well as the hydrostatic relation and are expressed as a function of height (z), Latitude (Lat) and areocentric solar longitude (Ls). The greatest adjustments are made at large optical depths such as tau greater than 1. The addition of the adjustment factors has led to better correspondence to TES Limb data from 0-60 km altitude as well as better agreement with MGS, ODY and MRO data at approximately 90-130 km altitude. Improved Mars-GRAM atmospheric simulations for various locations, times and dust conditions on Mars will be presented at the workshop session. The latest results validating Mars-GRAM 2010 versus Mars Climate Sounder data will also be presented. Mars-GRAM 2010 updates have resulted in improved atmospheric simulations which will be very important when beginning systems design, performance analysis, and operations planning for future aerocapture, aerobraking or landed missions to Mars.

  15. Additional Navigational Strategies Can Augment Odor-Gated Rheotaxis for Navigation under Conditions of Variable Flow.

    PubMed

    Vasey, Gabrielle; Lukeman, Ryan; Wyeth, Russell C

    2015-09-01

    The navigation strategies animals use to find sources of odor depend on the olfactory stimuli, the properties of flowing fluids, and the locomotory capabilities of the animal. In high Reynolds number environments, animals typically use odor-gated rheotaxis to find the source of turbulent odor plumes. This strategy succeeds because, although turbulence creates an intermittent chemical cue, the animal follows the (continuous) directional cue created by the flow that is transporting the chemical. However, in nature, animals may lose all contact with an odor plume as variations in the direction of bulk flow cause the plume to be rotated away before the animal reaches the source of the odor. Our goal was to use a mathematical model to test the hypothesis that strategies that augment odor-gated rheotaxis would be beneficial for finding the source of an odor plume in such variable flow. The model links a stochastic variable-direction odor plume with a turbulence-based intermittent chemical signal and four different movement strategies, including: odor-gated rheotaxis alone (as a control), odor-gated rheotaxis augmented by further rheotaxis in the absence of odor, odor-gated rheotaxis augmented by a random walk, and odor-gated rheotaxis augmented by movement actively guided by the heading of the flow when the odor was still present. We found that any of the three augmented strategies could improve on strict odor-gated rheotaxis. Moreover, variations in performance caused the best strategy to depend on the speed of movement of the animal and the magnitude of the variation in flow, and more subtly on the duration over which the augmented strategy was performed. For most combinations of parameters in the model, either augmenting with a random walk or following the last-known heading were the best-performing strategies. Overall, our results suggest that marine animals that rely on odor cues to navigate in turbulent environments may augment odor-gated rheotaxis with additional

  16. Enhancing the linear flow of fine granules through the addition of elongated particles

    PubMed Central

    Guo, Zhiguo; Chen, Xueli; Xu, Yang; Liu, Haifeng

    2015-01-01

    Sandglasses have been used to record time for thousands of years because of their constant flow rates; however, they now are drawing attention for their substantial scientific importance and extensive industrial applications. The presence of elongated particles in a binary granular system is believed to result in undesired flow because their shape implies a larger resistance to flow. However, our experiments demonstrate that the addition of elongated particles can substantially reduce the flow fluctuation of fine granules and produce a stable linear flow similar to that in an hourglass. On the basis of experimental data and previous reports of flow dynamics, we observed that the linear flow is driven by the “needle particle effect,” including flow orientation, reduced agglomeration, and local perturbation. This phenomenon is observed in several binary granular systems, including fine granules and secondary elongated particles, which demonstrates that our simple method can be widely applied to the accurate measurement of granular flows in industry. PMID:26551736

  17. Improvements in floating point addition/subtraction operations

    DOEpatents

    Farmwald, P.M.

    1984-02-24

    Apparatus is described for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

  18. Similarity between particles and bubbles as micro-additives in turbulent channel flow

    NASA Astrophysics Data System (ADS)

    Mito, Yoichi

    2015-11-01

    The acceleration of turbulent fluid flow in a vertical channel by the use of a uniform distribution of microparticles and of microbubbles has been examined by using a direct numerical simulation to calculate the fluid velocities seen by the additives. The flows considered are the downward gas flow to which solid particles of density ratio of 103 are added and the upward liquid flow to which bubbles of density ratio of 10-3 are added. Both additives, ranging in volume fraction up to 2 ×10-3 , are represented as solid spheres. The Froude numbers are chosen so as to have similar effects in both flows by the use of the same volume fraction of the additives. The fluid-phase momentum balance, integrated over the domain, is used to examine the changes in drag, wall friction and averaged feedback force of the non-stationary flow models. The feedback force per volume fraction is unchanged in the bubble flow. It decreases with increasing volume fraction and inertia of particles in the particle flow. Similarities between the two disperse flows are seen at small times for small volume fractions. Drag is reduced by both additives. The amount of reduced drag decreases with time at large times in the bubble flow, due to the increases in the accumulation of bubbles above walls. This work was supported by JSPS KAKENHI Grant Number 26420097.

  19. Improved Nozzle Testing Techniques in Transonic Flow

    DTIC Science & Technology

    1975-10-01

    the difficulties related to transonic testing techniques. The presence of a model mounting system, proximity of the tunnel walls, the method and amount...avec la methode exposee rtf 2. (b) Le coefficient de poussee interne KTJ , qui represente le precedent exprime en pressions relatives PQAJ KTi... method was developed to define a valid total pressure, based on a mast flow averaging procedure, for a distorted jet pipe flow. The results for the AGARD

  20. Improving complex kinship analyses with additional STR loci.

    PubMed

    Carboni, Ilaria; Iozzi, Sara; Nutini, Anna Lucia; Torricelli, Francesca; Ricci, Ugo

    2014-11-01

    In a standard paternity testing, mother, child, and alleged father are analyzed with STR markers using commercially available kits. Since Italian civil legislation does not have thresholds to confirm a paternity, paternity is practically proven when likelihood ratio increases prior probability of paternity to posterior, accepted by court as sufficient. However, in some cases the number of markers included in a commercial kit may be insufficient to conclusively prove or disprove a relationship between individuals, especially when complex family scenarios are suspected or indirect analyses are required. Additional genetic information can increase the values of the likelihood ratio regarding the detection of true parental relationships in a pedigree, while reducing the chances of false attributions (e.g. false paternities). In these cases the introduction of a 26Plex amplification system allows to examine 23-26 additional markers depending on the commercial kit used, thus increasing the statistical power of the kinship analysis. The PCR conditions were optimized for a multiplex amplification system and a new generation CE instrument. In order to demonstrate the utility of additional STRs markers, four complex kinship cases are presented.

  1. Investigations on drag reduction in turbulent pipe flows by addition of ionic and nonionic high polymers

    NASA Astrophysics Data System (ADS)

    Graeger, Helmut

    Drag reduction in turbulent pipe flow is obtained by addition of polymeric flow accelerator. Turbulent flow pattern is described on the basis of existing theories and reduction of loss of pressure heads is discussed. A turbulence rheometer is developed permitting the measurement of friction reduction for Reynolds numbers 1100 to 90,000. Effectiveness of water soluble polymer systems like polyacrylamide and coacrylate is studied in dependence of concentration, chemical composition, product aging and polymer chain deformation.

  2. Improved visualization of flow field measurements

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey Hilton

    1991-01-01

    A capability was developed that makes it possible to apply to measured flow field data the visualization tools developed to display numerical solutions for computational fluid dynamic problems. The measurement monitor surface (MMS) procedure was applied to the analysis of flow field measurements within a low aspect ratio transonic axial flow fan rotor obtained with 2-D laser anemometry. The procedure generates input for the visualization tools developed to display numerical solutions for computational fluid dynamics problems. The relative Mach number contour plots obtained by this method resemble the conventional contour plots obtained by more traditional methods. The results show that the MMS procedure can be used to generate input for the multidimensional processing and analysis tools developed for data from numerical flow field simulations. They show that an experimenter can apply the MMS procedure to his data and then use an interactive graphics program to display scalar quantities like the Mach number by profiles, carpet plots, contour lines, and surfaces using various colors. Also, flow directionality can be shown by display of vector fields and particle traces.

  3. Active shear flow control for improved combustion

    NASA Astrophysics Data System (ADS)

    Gutmark, E.; Parr, T. P.; Hanson-Parr, D. M.; Schadow, K. C.

    1990-01-01

    The acoustical and fluid dynamic facets of an excited premixed flame were studied experimentally to evaluate possibilities for development of a stabilizing closed-loop control system. The flame was analyzed as a nonlinear system which includes different subcomponents: acoustics, fluid dynamics, and chemical reaction. Identification of the acoustical and fluid dynamics subsystems is done by analyzing the transfer function, which was obtained by driving the system with both white-noise and a frequency-sweeping sine-wave. The features obtained by this analysis are compared to results of flow visualization and hot-wire flow-field and spectral measurements. The acoustical subsystem is determined by the resonant acoustic modes of the settling chamber. These modes are subsequently filtered and amplified by the flow shear layer, whose instability characteristics are dominated by the preferred mode frequency.

  4. Improving the assessment of instream flow needs for fish populations

    SciTech Connect

    Sale, M.J. ); Otto, R.G. and Associates, Arlington, VA )

    1991-01-01

    Instream flow requirements are one of the most frequent and most costly environmental issues that must be addressed in developing hydroelectric projects. Existing assessment methods for determining instream flow requirements have been criticized for not including all the biological response mechanisms that regulate fishery resources. A new project has been initiated to study the biological responses of fish populations to altered stream flows and to develop improved ways of managing instream flows. 21 refs., 3 figs.

  5. Additional sampling directions improve detection range of wireless radiofrequency probes

    PubMed Central

    Mada, Marius; Carpenter, T. Adrian; Sawiak, Stephen J.; Williams, Guy B.

    2015-01-01

    Purpose While MRI is enhancing our knowledge about the structure and function of the human brain, subject motion remains a problem in many clinical applications. Recently, the use of wireless radiofrequency markers with three one‐dimensional (1D) navigators for prospective correction was demonstrated. This method is restricted in the range of motion that can be corrected, however, because of limited information in the 1D readouts. Methods Here, the limitation of techniques for disambiguating marker locations was investigated. It was shown that including more sampling directions extends the tracking range for head rotations. The efficiency of trading readout resolution for speed was explored. Results Tracking of head rotations was demonstrated from −19.2 to 34.4°, −2.7 to 10.0°, and −60.9 to 70.9° in the x‐, y‐, and z‐directions, respectively. In the presence of excessive head motion, the deviation of marker estimates from SPM8 was reduced by 17.1% over existing three‐projection methods. This was achieved by using an additional seven directions, extending the time needed for readouts by a factor of 3.3. Much of this increase may be circumvented by reducing resolution, without compromising accuracy. Conclusion Including additional sampling directions extends the range in which markers can be used, for patients who move a lot. Magn Reson Med 76:913–918, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:26418189

  6. Improved dual flow aluminum hydrogen peroxide battery

    SciTech Connect

    Marsh, C.; Licht, S.L.; Matthews, D.

    1993-11-30

    A novel dual flow battery configuration is provided comprising an aqueous hydrogen peroxide catholyte, an aqueous anolyte, a porous solid electrocatalyst capable of reducing said hydrogen peroxide and separating said anolyte, and an aluminum anode positioned within said anolyte. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode.

  7. Improved dual flow aluminum hydrogen peroxide battery

    NASA Astrophysics Data System (ADS)

    Marsh, Catherine; Licht, Stuart L.; Matthews, Donna

    1993-11-01

    A novel dual flow battery configuration is provided comprising an aqueous hydrogen peroxide catholyte, an aqueous anolyte, a porous solid electrocatalyst capable of reducing said hydrogen peroxide and separating said anolyte, and an aluminum anode positioned within said anolyte. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode.

  8. The SUPERFAMILY database in 2004: additions and improvements.

    PubMed

    Madera, Martin; Vogel, Christine; Kummerfeld, Sarah K; Chothia, Cyrus; Gough, Julian

    2004-01-01

    The SUPERFAMILY database provides structural assignments to protein sequences and a framework for analysis of the results. At the core of the database is a library of profile Hidden Markov Models that represent all proteins of known structure. The library is based on the SCOP classification of proteins: each model corresponds to a SCOP domain and aims to represent an entire superfamily. We have applied the library to predicted proteins from all completely sequenced genomes (currently 154), the Swiss-Prot and TrEMBL databases and other sequence collections. Close to 60% of all proteins have at least one match, and one half of all residues are covered by assignments. All models and full results are available for download and online browsing at http://supfam.org. Users can study the distribution of their superfamily of interest across all completely sequenced genomes, investigate with which other superfamilies it combines and retrieve proteins in which it occurs. Alternatively, concentrating on a particular genome as a whole, it is possible first, to find out its superfamily composition, and secondly, to compare it with that of other genomes to detect superfamilies that are over- or under-represented. In addition, the webserver provides the following standard services: sequence search; keyword search for genomes, superfamilies and sequence identifiers; and multiple alignment of genomic, PDB and custom sequences.

  9. How to detect the Granger-causal flow direction in the presence of additive noise?

    PubMed

    Vinck, Martin; Huurdeman, Lisanne; Bosman, Conrado A; Fries, Pascal; Battaglia, Francesco P; Pennartz, Cyriel M A; Tiesinga, Paul H

    2015-03-01

    Granger-causality metrics have become increasingly popular tools to identify directed interactions between brain areas. However, it is known that additive noise can strongly affect Granger-causality metrics, which can lead to spurious conclusions about neuronal interactions. To solve this problem, previous studies have proposed the detection of Granger-causal directionality, i.e. the dominant Granger-causal flow, using either the slope of the coherency (Phase Slope Index; PSI), or by comparing Granger-causality values between original and time-reversed signals (reversed Granger testing). We show that for ensembles of vector autoregressive (VAR) models encompassing bidirectionally coupled sources, these alternative methods do not correctly measure Granger-causal directionality for a substantial fraction of VAR models, even in the absence of noise. We then demonstrate that uncorrelated noise has fundamentally different effects on directed connectivity metrics than linearly mixed noise, where the latter may result as a consequence of electric volume conduction. Uncorrelated noise only weakly affects the detection of Granger-causal directionality, whereas linearly mixed noise causes a large fraction of false positives for standard Granger-causality metrics and PSI, but not for reversed Granger testing. We further show that we can reliably identify cases where linearly mixed noise causes a large fraction of false positives by examining the magnitude of the instantaneous influence coefficient in a structural VAR model. By rejecting cases with strong instantaneous influence, we obtain an improved detection of Granger-causal flow between neuronal sources in the presence of additive noise. These techniques are applicable to real data, which we demonstrate using actual area V1 and area V4 LFP data, recorded from the awake monkey performing a visual attention task.

  10. Improved flow cytometer measurement of binding assays

    DOEpatents

    Saunders, G.C.

    1984-05-30

    The invention relates to a method of measuring binding assays carried out with different size particles wherein the binding assay sample is run through a flow cytometer without separating the sample from the marking agent. The amount of a binding reactant present in a sample is determined by providing particles with a coating of binder and also a known quantity of smaller particles with a coating of binder reactant. The binding reactant is the same as the binding reactant present in the sample. The smaller particles also contain a fluorescent chemical. The particles are combined with the sample and the binding reaction is allowed to occur for a set length of time followed by combining the smaller particles with the mixture of the particles and the sample produced and allowing the binding reactions to proceed to equilibrium. The fluorescence and light scatter of the combined mixture is then measured as the combined mixture passes through a flow cytometer equipped with a laser to bring about fluorescence, and the number and strength of fluorescent events are compared. A similar method is also provided for determining the amount of antigen present in the sample by providing spheres with an antibody coating and some smaller spheres with an antigen coating. (LEW)

  11. Aerosil for the improvement of the flow behavior of powdered substances

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The tendency of powdered substances to agglomerate and stick together is studied. The highly dispersed silicic acid Aerosil (tradename) is studied as an agent to improve the free flowing characteristics of powdered materials. It was concluded that the use of Aerosil 200, Aerosil R 972, aluminum oxide C and sylicic acid D 17 as flow agents caused broad improvements in the flow properties of powders. Additionally, the sifting, dispersion, and spray behavior, as well as the grinding and air separation characteristics of powders were improved.

  12. Performance of Improved High-Order Filter Schemes for Turbulent Flows with Shocks

    NASA Technical Reports Server (NTRS)

    Kotov, Dmitry Vladimirovich; Yee, Helen M C.

    2013-01-01

    The performance of the filter scheme with improved dissipation control ? has been demonstrated for different flow types. The scheme with local ? is shown to obtain more accurate results than its counterparts with global or constant ?. At the same time no additional tuning is needed to achieve high accuracy of the method when using the local ? technique. However, further improvement of the method might be needed for even more complex and/or extreme flows.

  13. IMPROVED BIOMASS UTILIZATION THROUGH REMOTE FLOW SENSING

    SciTech Connect

    Washington University- St. Louis: Muthanna Al-Dahhan E-mail: muthanna@wustl.edu Rajneesh Varma Khursheed Karim Mehul Vesvikar Rebecca Hoffman Oak Ridge National Laboratory: David Depaoli, Email: depaolidw@ornl.gov Thomas Klasson Alan L. Wintenberg Charles W Alexander Lloyd Clonts Iowa Energy Center Norm Olson Email: nolson@energy.iastate.edu

    2007-03-26

    The growth of the livestock industry provides a valuable source of affordable, sustainable, and renewable bioenergy, while also requiring the safe disposal of the large quantities of animal wastes (manure) generated at dairy, swine, and poultry farms. If these biomass resources are mishandled and underutilized, major environmental problems will be created, such as surface and ground water contamination, odors, dust, ammonia leaching, and methane emission. Anaerobic digestion of animal wastes, in which microorganisms break down organic materials in the absence of oxygen, is one of the most promising waste treatment technologies. This process produces biogas typically containing {approx}65% methane and {approx}35% carbon dioxide. The production of biogas through anaerobic digestion from animal wastes, landfills, and municipal waste water treatment plants represents a large source of renewable and sustainable bio-fuel. Such bio-fuel can be combusted directly, used in internal combustion engines, converted into methanol, or partially oxidized to produce synthesis gas (a mixture of hydrogen and carbon monoxide) that can be converted to clean liquid fuels and chemicals via Fischer-Tropsch synthesis. Different design and mixing configurations of anaerobic digesters for treating cow manure have been utilized commercially and/or tested on a laboratory scale. These digesters include mechanically mixed, gas recirculation mixed, and slurry recirculation mixed designs, as well as covered lagoon digesters. Mixing is an important parameter for successful performance of anaerobic digesters. It enhances substrate contact with the microbial community; improves pH, temperature and substrate/microorganism uniformity; prevents stratification and scum accumulation; facilitates the removal of biogas from the digester; reduces or eliminates the formation of inactive zones (dead zones); prevents settling of biomass and inert solids; and aids in particle size reduction. Unfortunately

  14. Radiant energy receiver having improved coolant flow control means

    DOEpatents

    Hinterberger, H.

    1980-10-29

    An improved coolant flow control for use in radiant energy receivers of the type having parallel flow paths is disclosed. A coolant performs as a temperature dependent valve means, increasing flow in the warmer flow paths of the receiver, and impeding flow in the cooler paths of the receiver. The coolant has a negative temperature coefficient of viscosity which is high enough such that only an insignificant flow through the receiver is experienced at the minimum operating temperature of the receiver, and such that a maximum flow is experienced at the maximum operating temperature of the receiver. The valving is accomplished by changes in viscosity of the coolant in response to the coolant being heated and cooled. No remotely operated valves, comparators or the like are needed.

  15. Improving flow distribution in influent channels using computational fluid dynamics.

    PubMed

    Park, No-Suk; Yoon, Sukmin; Jeong, Woochang; Lee, Seungjae

    2016-10-01

    Although the flow distribution in an influent channel where the inflow is split into each treatment process in a wastewater treatment plant greatly affects the efficiency of the process, and a weir is the typical structure for the flow distribution, to the authors' knowledge, there is a paucity of research on the flow distribution in an open channel with a weir. In this study, the influent channel of a real-scale wastewater treatment plant was used, installing a suppressed rectangular weir that has a horizontal crest to cross the full channel width. The flow distribution in the influent channel was analyzed using a validated computational fluid dynamics model to investigate (1) the comparison of single-phase and two-phase simulation, (2) the improved procedure of the prototype channel, and (3) the effect of the inflow rate on flow distribution. The results show that two-phase simulation is more reliable due to the description of the free-surface fluctuations. It should first be considered for improving flow distribution to prevent a short-circuit flow, and the difference in the kinetic energy with the inflow rate makes flow distribution trends different. The authors believe that this case study is helpful for improving flow distribution in an influent channel.

  16. Improvement of Flow Quality in NAL Chofu Mach 10 Nozzle

    NASA Technical Reports Server (NTRS)

    Lacey, John; Inoue, Yasutoshi; Higashida, Akio; Inoue, Manabu; Ishizaka, Kouichi; Korte, John J.

    2002-01-01

    As a result of CFD analysis and remachining of the nozzle, the flow quality of the Mach 10 Hypersonic Wind Tunnel at NAL Chofu, Japan was improved. The subsequent test results validated the CFD analytical predictions by NASA and MHL.

  17. Suppression of flow pulsation activity by relaxation process of additive effect on viscous media transport

    NASA Astrophysics Data System (ADS)

    Kharlamov, S.; Dedeyev, P.; Meucci, L.; Shenderova, I.; Manastirniy, A.; Usenko, M.

    2015-11-01

    The article presents the analysis of the processes occurring together with the turbulent transfer of impulse in mixture of hydrocarbon fluid and polymer solutions (anti-turbulent additives). The study evaluates complex shear flows by popular theoretical and practical methods. Understanding of hydrodynamic and dissipative effects of laminar-turbulent transition tightening and turbulence suppression is provided. The peculiarities of "thin" flow structure in pipeline zones with complex shape walls are evaluated. Recommendations to forecast the local flow parameters, calculation of hydraulic resistance are given.

  18. Formation of the geometrically controlled carbon coils by manipulating the additive gas (SF6) flow rate.

    PubMed

    Jeon, Young-Chul; Kim, Sung-Hoon

    2012-07-01

    Carbon coils could be synthesized using C2H2/H2 as source gases and SF6 as an incorporated additive gas under the thermal chemical vapor deposition system. The nickel catalyst layer deposition and then hydrogen plasma pretreatment were performed prior to the carbon coils deposition reaction. The flow rate and the injection time of SF6 varied according to the different reaction processes. Geometries of carbon coils developed from embryos to nanosized coils with increasing SF, flow rate from 5 to 35 sccm under the short SF6 flow injection time (5 minutes) condition. The gradual development of carbon coils geometries from nanosized to microsized types could be observed with increasing SF6 flow rate under the full time (90 minutes) SF6 flow injection condition. The flow rate of SF6 for the coil-type geometry formation should be more than or at least equal to the flow rate of carbon source gas (C2H2). A longer injection time of SF6 flow would increase the size of coils diameters from nanometer to micrometer.

  19. Trading water to improve environmental flow outcomes

    NASA Astrophysics Data System (ADS)

    Connor, Jeffery D.; Franklin, Brad; Loch, Adam; Kirby, Mac; Wheeler, Sarah Ann

    2013-07-01

    As consumptive extractions and water scarcity pressures brought about by climate change increase in many world river basins, so do the risks to water-dependent ecological assets. In response, public or not for profit environmental water holders (EWHs) have been established in many areas and bestowed with endowments of water and mandates to manage water for ecological outcomes. Water scarcity has also increasingly spawned water trade arrangements in many river basins, and in many instances, EWHs are now operating in water markets. A number of EWHs, especially in Australia, begin with an endowment of permanent water entitlements purchased from irrigators. Such water entitlements typically have relatively constant interannual supply profiles that often do not match ecological water demand involving flood pulses and periods of drying. This article develops a hydrologic-economic simulation model of the Murrumbidgee catchment within the Murray-Darling Basin to assess the scope of possibilities to improve environmental outcomes through EWH trading on an annual water lease market. We find that there are some modest opportunities for EWHs to improve environmental outcomes through water trade. The best opportunities occur in periods of drought and for ecological outcomes that benefit from moderately large floods. We also assess the extent to which EWH trading in annual water leases may create pecuniary externalities via bidding up or down the water lease prices faced by irrigators. Environmental water trading is found to have relatively small impacts on water market price outcomes. Overall our results suggest that the benefits of developing EWH trading may well justify the costs.

  20. Environmental Data Flow Six Sigma Process Improvement Savings Overview

    SciTech Connect

    Paige, Karen S

    2015-05-20

    An overview of the Environmental Data Flow Six Sigma improvement project covers LANL’s environmental data processing following receipt from the analytical laboratories. The Six Sigma project identified thirty-three process improvements, many of which focused on cutting costs or reducing the time it took to deliver data to clients.

  1. An improved turbulence model for rotating shear flows*

    NASA Astrophysics Data System (ADS)

    Nagano, Yasutaka; Hattori, Hirofumi

    2002-01-01

    In the present study, we construct a turbulence model based on a low-Reynolds-number non-linear k e model for turbulent flows in a rotating channel. Two-equation models, in particular the non-linear k e model, are very effective for solving various flow problems encountered in technological applications. In channel flows with rotation, however, the explicit effects of rotation only appear in the Reynolds stress components. The exact equations for k and e do not have any explicit terms concerned with the rotation effects. Moreover, the Coriolis force vanishes in the momentum equation for a fully developed channel flow with spanwise rotation. Consequently, in order to predict rotating channel flows, after proper revision the Reynolds stress equation model or the non-linear eddy viscosity model should be used. In this study, we improve the non-linear k e model so as to predict rotating channel flows. In the modelling, the wall-limiting behaviour of turbulence is also considered. First, we evaluated the non-linear k e model using the direct numerical simulation (DNS) database for a fully developed rotating turbulent channel flow. Next, we assessed the non-linear k e model at various rotation numbers. Finally, on the basis of these assessments, we reconstruct the non-linear k e model to calculate rotating shear flows, and the proposed model is tested on various rotation number channel flows. The agreement with DNS and experiment data is quite satisfactory.

  2. A novel approach to improve operation and performance in flow field-flow fractionation.

    PubMed

    Johann, Christoph; Elsenberg, Stephan; Roesch, Ulrich; Rambaldi, Diana C; Zattoni, Andrea; Reschiglian, Pierluigi

    2011-07-08

    A new system design and setup are proposed for the combined use of asymmetrical flow field-flow fractionation (AF4) and hollow-fiber flow field-flow fractionation (HF5) within the same instrumentation. To this purpose, three innovations are presented: (a) a new flow control scheme where focusing flow rates are measured in real time allowing to adjust the flow rate ratio as desired; (b) a new HF5 channel design consisting of two sets of ferrule, gasket and cap nut used to mount the fiber inside a tube. This design provides a mechanism for effective and straightforward sealing of the fiber; (c) a new AF4 channel design with only two fluid connections on the upper plate. Only one pump is needed to deliver the necessary flow rates. In the focusing/relaxation step the two parts of the focusing flow and a bypass flow flushing the detectors are created with two splits of the flow from the pump. In the elution mode the cross-flow is measured and controlled with a flow controller device. This leads to reduced pressure pulsations in the channel and improves signal to noise ratio in the detectors. Experimental results of the separation of bovine serum albumin (BSA) and of a mix of four proteins demonstrate a significant improvement in the HF5 separation performance, in terms of efficiency, resolution, and run-to-run reproducibility compared to what has been reported in the literature. Separation performance in HF5 mode is shown to be comparable to the performance in AF4 mode using a channel with two connections in the upper plate.

  3. Improved numerical methods for turbulent viscous recirculating flows

    NASA Technical Reports Server (NTRS)

    Turan, A.; Vandoormaal, J. P.

    1988-01-01

    The performance of discrete methods for the prediction of fluid flows can be enhanced by improving the convergence rate of solvers and by increasing the accuracy of the discrete representation of the equations of motion. This report evaluates the gains in solver performance that are available when various acceleration methods are applied. Various discretizations are also examined and two are recommended because of their accuracy and robustness. Insertion of the improved discretization and solver accelerator into a TEACH mode, that has been widely applied to combustor flows, illustrates the substantial gains to be achieved.

  4. Drag Reduction by Laser-Plasma Energy Addition in Hypersonic Flow

    SciTech Connect

    Oliveira, A. C.; Minucci, M. A. S.; Toro, P. G. P.; Chanes, J. B. Jr; Myrabo, L. N.

    2008-04-28

    An experimental study was conducted to investigate the drag reduction by laser-plasma energy addition in a low density Mach 7 hypersonic flow. The experiments were conducted in a shock tunnel and the optical beam of a high power pulsed CO{sub 2} TEA laser operating with 7 J of energy and 30 MW peak power was focused to generate the plasma upstream of a hemispherical model installed in the tunnel test section. The non-intrusive schlieren optical technique was used to visualize the effects of the energy addition to hypersonic flow, from the plasma generation until the mitigation of the shock wave profile over the model surface. Aside the optical technique, a piezoelectric pressure transducer was used to measure the impact pressure at stagnation point of the hemispherical model and the pressure reduction could be observed.

  5. Improvement of a 2D numerical model of lava flows

    NASA Astrophysics Data System (ADS)

    Ishimine, Y.

    2013-12-01

    I propose an improved procedure that reduces an improper dependence of lava flow directions on the orientation of Digital Elevation Model (DEM) in two-dimensional simulations based on Ishihara et al. (in Lava Flows and Domes, Fink, JH eds., 1990). The numerical model for lava flow simulations proposed by Ishihara et al. (1990) is based on two-dimensional shallow water model combined with a constitutive equation for a Bingham fluid. It is simple but useful because it properly reproduces distributions of actual lava flows. Thus, it has been regarded as one of pioneer work of numerical simulations of lava flows and it is still now widely used in practical hazard prediction map for civil defense officials in Japan. However, the model include an improper dependence of lava flow directions on the orientation of DEM because the model separately assigns the condition for the lava flow to stop due to yield stress for each of two orthogonal axes of rectangular calculating grid based on DEM. This procedure brings a diamond-shaped distribution as shown in Fig. 1 when calculating a lava flow supplied from a point source on a virtual flat plane although the distribution should be circle-shaped. To improve the drawback, I proposed a modified procedure that uses the absolute value of yield stress derived from both components of two orthogonal directions of the slope steepness to assign the condition for lava flows to stop. This brings a better result as shown in Fig. 2. Fig. 1. (a) Contour plots calculated with the original model of Ishihara et al. (1990). (b) Contour plots calculated with a proposed model.

  6. Additive global cerebral blood flow normalization in arterial spin labeling perfusion imaging.

    PubMed

    Stewart, Stephanie B; Koller, Jonathan M; Campbell, Meghan C; Perlmutter, Joel S; Black, Kevin J

    2015-01-01

    To determine how different methods of normalizing for global cerebral blood flow (gCBF) affect image quality and sensitivity to cortical activation, pulsed arterial spin labeling (pASL) scans obtained during a visual task were normalized by either additive or multiplicative normalization of modal gCBF. Normalization by either method increased the statistical significance of cortical activation by a visual stimulus. However, image quality was superior with additive normalization, whether judged by intensity histograms or by reduced variability within gray and white matter.

  7. Improved numerical methods for turbulent viscous recirculating flows

    NASA Technical Reports Server (NTRS)

    Vandoormaal, J. P.; Turan, A.; Raithby, G. D.

    1986-01-01

    The objective of the present study is to improve both the accuracy and computational efficiency of existing numerical techniques used to predict viscous recirculating flows in combustors. A review of the status of the study is presented along with some illustrative results. The effort to improve the numerical techniques consists of the following technical tasks: (1) selection of numerical techniques to be evaluated; (2) two dimensional evaluation of selected techniques; and (3) three dimensional evaluation of technique(s) recommended in Task 2.

  8. An improved near-wall treatment for turbulent channel flows

    NASA Astrophysics Data System (ADS)

    El Gharbi, Najla; Absi, Rafik; Benzaoui, Ahmed; Bennacer, Rachid

    2011-01-01

    The success of predictions of wall-bounded turbulent flows requires an accurate description of the flow in the near-wall region. This article presents a comparative study between different near-wall treatments and presents an improved method. The study is applied to fully developed plane channel flow (i.e. the flow between two infinitely large plates). Simulations were performed using Fluent. Near-wall treatments available in Fluent were tested: standard wall functions, non-equilibrium wall function and enhanced wall treatment. A user defined function (UDF), based on an analytical profile for the turbulent kinetic energy (Absi, R., 2008. Analytical solutions for the modeled k-equation. ASME Journal of Applied Mechanics, 75 (4), 044501), is developed and implemented. Predicted turbulent kinetic energy profiles are presented and validated by DNS data.

  9. Improvement of hemodynamic performance using novel helical flow vena cava filter design

    PubMed Central

    Chen, Ying; Zhang, Peng; Deng, Xiaoyan; Fan, Yubo; Xing, Yubin; Xing, Ning

    2017-01-01

    We propose a vena cava filter in which helical flow is created in the filter’s working zone to minimize filter blockage by trapped clots and facilitate the lysis of trapped clots. To validate this new design, we compared five helical flow inducers with different thread pitches in terms of blood flow patterns in the filter. The vena cava was reconstructed based on computed tomography images. Both the numerical simulation and in vitro experiment revealed that the helical flow inducer can effectively create a helical flow in the vessel, thereby subduing the filter structure’s adverse disruption to blood flow, and increasing flow-induced shear stress in the filter center. In addition, the smaller thread pitch helical flow inducer reduced the oscillating shear index and relative residence time on the vessel wall. Moreover, we observed that the helical flow inducer in the vena cava could induce flow rotation both in clockwise and counterclockwise directions. In conclusion, the new design of the filter with the smaller thread pitch inducer is advantageous over the traditional filter in terms of improving local hemodynamics, which may reduce thrombosis build-up after deployment. PMID:28112186

  10. Modular system for studying tonal sound excitation in resonators with heat addition and mean flow.

    PubMed

    Matveev, Konstantin I; Hernandez, Rafael

    2012-03-01

    An educational experimental system has been developed for studying tonal sound generation in acoustic resonators. Tones are excited by either heat addition or vortex shedding in the presence of mean flow. The system construction is straightforward and inexpensive. Several test arrangements and experimental data are described in this paper. The experimental setups include a modified Rijke tube, a standing-wave thermoacoustic engine, a baffled tube with mean flow, and an acoustic energy harvester with a piezoelement. Simplified mathematical models for interpreting data are discussed, and references are provided to literature with more advanced analyses. The developed system can assist both graduate and undergraduate students in understanding acoustic instabilities via conducting and analyzing interesting experiments.

  11. An improved stochastic separated flow model for turbulent two-phase flow

    NASA Astrophysics Data System (ADS)

    Chan, C. K.; Zhang, H. Q.; Lau, K. S.

    An improved stochastic separated flow model is proposed to obtain reasonable statistical characteristics of a two-phase flow. Effects of the history of a particle and its current trajectory position on the mean-square fluctuating velocity of the dispersed phase are continuously considered in this model. Comparing with the conventional model, results using the improved model are more reasonable and can also be obtained more easily. Furthermore, the improved model requires less computational particles for simulating dispersed-phase turbulence at the beginning of the stochastic trajectory. In this paper, an application in turbulent two-phase flow of planar mixing layer is carried out. Numerical results including velocity, mean-square fluctuating velocity, particle number density and pdf of fluctuation velocity of dispersed phase are shown to compare well with experimental data.

  12. Process for improving moisture resistance of epoxy resins by addition of chromium ions

    NASA Technical Reports Server (NTRS)

    St.clair, A. K.; Stoakley, D. M.; St.clair, T. L.; Singh, J. J. (Inventor)

    1985-01-01

    A process for improving the moisture resistance properties of epoxidized TGMDA and DGEBA resin system by chemically incorporating chromium ions is described. The addition of chromium ions is believed to prevent the absorption of water molecules.

  13. Improving the environmental and performance characteristics of vehicles by introducing the surfactant additive into gasoline.

    PubMed

    Magaril, Elena; Magaril, Romen

    2016-09-01

    The operation of modern vehicles requires the introduction of package of fuel additives to ensure the required level of operating characteristics, some of which cannot be achieved by current oil refining methods. The use of additives allows flexibility of impact on the properties of the fuel at minimal cost, increasing the efficiency and environmental safety of vehicles. Among the wide assortment of additives available on the world market, many are surfactants. It has been shown that the introduction of some surfactants into gasoline concurrently reduces losses from gasoline evaporation, improves the mixture formation during injection of gasoline into the engine and improves detergent and anticorrosive properties. The surfactant gasoline additive that provides significant improvement in the quality of gasoline used and environmental and operating characteristics of vehicles has been developed and thoroughly investigated. The results of studies confirming the efficiency of the gasoline additive application are herein presented.

  14. Smart low flow signature metrics for an improved overall performance evaluation of hydrological models

    NASA Astrophysics Data System (ADS)

    Pfannerstill, Matthias; Guse, Björn; Fohrer, Nicola

    2014-03-01

    Hydrological models have to be calibrated accurately to provide reasonable model results. For a concise model evaluation, the different phases of the hydrograph have to be considered in multi-metric frameworks with appropriate performance metrics. Low and high flows need to be reproduced simultaneously without neglecting the other phases of the hydrograph. In this paper, we highlight the relevance of very low and low flows with separate performance metrics. We present a multi-metric evaluation framework to identify calibration runs, which represent the different phases of the hydrograph precisely. A stepwise evaluation was done with commonly used statistical performance metrics (Nash-Sutcliffe, percent bias) and signature metrics, which are based on the flow duration curve (FDC). In order to consider a fairly balanced evaluation between high and low flow phases, we divided the flow duration curve into segments of high, medium and low flow phases, and additionally into very high and very low flow phases. The model performance in these segments was evaluated separately with the root mean square error (RMSE). Our results show that this evaluation method leads to an improved selection of good calibration runs to enhance the overall model performance by the refined segmentation of FDC. By combining performance metrics for high flow conditions with low flow conditions, this study demonstrates the challenge of calibrating a model with a satisfactory performance in high and low phases simultaneously. Consequently, we conclude that an additional performance metric for very low flows should be included in model analyzes to improve the overall performance in all phases of the hydrograph.

  15. Effectiveness of Additives in Improving Fuel Lubricity and Preventing Pump Failure at High Temperature

    DTIC Science & Technology

    2013-01-01

    the specified 1,700 rpm, the housing pressure on pump No. 1 dropped significantly. Fuel began spewing out of test stand gear box and the pump seized...UNCLASSIFIED EFFECTIVENESS OF ADDITIVES IN IMPROVING FUEL LUBRICITY AND PREVENTING PUMP FAILURE AT HIGH TEMPERATURE INTERIM REPORT TFLRF...UNCLASSIFIED EFFECTIVENESS OF ADDITIVES IN IMPROVING FUEL LUBRICITY AND PREVENTING PUMP FAILURE AT HIGH TEMPERATURE INTERIM REPORT TFLRF No. 437

  16. Acetate Salts as Nonhalogen Additives To Improve Perovskite Film Morphology for High-Efficiency Solar Cells.

    PubMed

    Wu, Qiliang; Zhou, Pengcheng; Zhou, Weiran; Wei, Xiangfeng; Chen, Tao; Yang, Shangfeng

    2016-06-22

    A two-step method has been popularly adopted to fabricate a perovskite film of planar heterojunction organo-lead halide perovskite solar cells (PSCs). However, this method often generates uncontrollable film morphology with poor coverage. Herein, we report a facile method to improve perovskite film morphology by incorporating a small amount of acetate (CH3COO(-), Ac(-)) salts (NH4Ac, NaAc) as nonhalogen additives in CH3NH3I solution used for immersing PbI2 film, resulting in improved CH3NH3PbI3 film morphology. Under the optimized NH4Ac additive concentration of 10 wt %, the best power conversion efficiency (PCE) reaches 17.02%, which is enhanced by ∼23.2% relative to that of the pristine device without additive, whereas the NaAc additive does not lead to an efficiency enhancement despite the improvement of the CH3NH3PbI3 film morphology. SEM study reveals that NH4Ac and NaAc additives can both effectively improve perovskite film morphology by increasing the surface coverage via diminishing pinholes. The improvement on CH3NH3PbI3 film morphology is beneficial for increasing the optical absorption of perovskite film and improving the interfacial contact at the perovskite/spiro-OMeTAD interface, leading to the increase of short-circuit current and consequently efficiency enhancement of the PSC device for NH4Ac additive only.

  17. Simulation of flow in a continuous galvanizing bath: Part I. Thermal effects of ingot addition

    NASA Astrophysics Data System (ADS)

    Ajersch, F.; Ilinca, F.; Hétu, J.-F.

    2004-02-01

    A numerical analysis has been developed to simulate the velocity and temperature fields in an industrial galvanizing bath for the continuous coating of steel strip. Operating variables such as ingot addition, line speed, and inductor mixing were evaluated in order to determine their effect on the velocity and temperature distribution in the bath. The simulations were carried out using high-performance computational fluid-dynamics software developed at the Industrial Materials Institute of the National Research Council Canada (IMI-NRC) in solving the incompressible Navier-Stokes equations for steady-state and transient turbulent flow using the k-ɛ model. Cases with and without temperature-dependent density conditions were considered. It was found that the strip velocity does not alter the global flow pattern but modifies the velocities in the snout, near the strip, and near the sink and guide rolls. At a low inductor capacity, the effect of induced mixing is small but is considerably increased at the maximum inductor capacities used during ingot-melting periods. When considering the thermal effects, the flow is affected by variations in density especially near the inductors and the ingot, while little effect is observed near the sheet-and-roller region. Thermal effects are also amplified when the inductor operates at high capacity during ingot melting. The simulations allow visualization of regions of varying velocity and temperature fields and clearly illustrate the mixed and stagnant zones for different operating conditions.

  18. Improved numerical methods for turbulent viscous recirculating flows

    NASA Technical Reports Server (NTRS)

    Turan, A.

    1985-01-01

    The hybrid-upwind finite difference schemes employed in generally available combustor codes possess excessive numerical diffusion errors which preclude accurate quantative calculations. The present study has as its primary objective the identification and assessment of an improved solution algorithm as well as discretization schemes applicable to analysis of turbulent viscous recirculating flows. The assessment is carried out primarily in two dimensional/axisymetric geometries with a view to identifying an appropriate technique to be incorporated in a three-dimensional code.

  19. Measurement Requirements for Improved Modeling of Arcjet Facility Flows

    NASA Technical Reports Server (NTRS)

    Fletcher, Douglas G.

    2000-01-01

    Current efforts to develop new reusable launch vehicles and to pursue low-cost robotic planetary missions have led to a renewed interest in understanding arc-jet flows. Part of this renewed interest is concerned with improving the understanding of arc-jet test results and the potential use of available computational-fluid- dynamic (CFD) codes to aid in this effort. These CFD codes have been extensively developed and tested for application to nonequilibrium, hypersonic flow modeling. It is envisioned, perhaps naively, that the application of these CFD codes to the simulation of arc-jet flows would serve two purposes: first. the codes would help to characterize the nonequilibrium nature of the arc-jet flows; and second. arc-jet experiments could potentially be used to validate the flow models. These two objectives are, to some extent, mutually exclusive. However, the purpose of the present discussion is to address what role CFD codes can play in the current arc-jet flow characterization effort, and whether or not the simulation of arc-jet facility tests can be used to eva1uate some of the modeling that is used to formu1ate these codes. This presentation is organized into several sections. In the introductory section, the development of large-scale, constricted-arc test facilities within NASA is reviewed, and the current state of flow diagnostics using conventional instrumentation is summarized. The motivation for using CFD to simulate arc-jet flows is addressed in the next section, and the basic requirements for CFD models that would be used for these simulations are briefly discussed. This section is followed by a more detailed description of experimental measurements that are needed to initiate credible simulations and to evaluate their fidelity in the different flow regions of an arc-jet facility. Observations from a recent combined computational and experiment.al investigation of shock-layer flows in a large-scale arc-jet facility are then used to illustrate the

  20. Schlieren Visualization of the Energy Addition by Multi Laser Pulse in Hypersonic Flow

    SciTech Connect

    Oliveira, A. C.; Minucci, M. A. S.; Toro, P. G. P.; Chanes, J. B. Jr; Myrabo, L. N.

    2008-04-28

    The experimental results of the energy addition by multi laser pulse in Mach 7 hypersonic flow are presented. Two high power pulsed CO{sub 2} TEA lasers (TEA1 5.5 J, TEA2 3.9 J) were assembled sharing the same optical cavity to generate the plasma upstream of a hemispherical model installed in the tunnel test section. The lasers can be triggered with a selectable time delay and in the present report the results obtained with delay between 30 {mu}s and 80 {mu}s are shown. The schlieren technique associated with a high speed camera was used to accomplish the influence of the energy addition in the mitigation of the shock wave formed on the model surface by the hypersonic flow. A piezoelectric pressure transducer was used to obtain the time history of the impact pressure at stagnation point of the model and the pressure reduction could be measured. The total recovery of the shock wave between pulses as well as the prolonged effect of the mitigation without recovery was observed by changing the delay.

  1. Improving solubilization in microemulsions with additives. 1. The lipophilic linker role

    SciTech Connect

    Graciaa, A.; Lachaise, J.; Cucuphat, C. ); Bourrel, M. ); Salager, J.L. )

    1993-03-01

    Very lipophilic additives are able to substantially improve the solubilization in surfactant-oil-water microemulsions. The so-called lipophilic linker effect is studied, and its role is discussed. It is shown that the presence of a very lipophilic amphiphilic additive may improve substantially the solubilization in microemulsions. This substance is called a lipophilic linker because its preferential orientation in the oil layers next to the interface might provide some ordering of the oil molecules as well as an additional link with the surfactant. Both effects result in a higher interaction on the oil side of the interface. 21 refs., 5 figs., 1 tab.

  2. Numerical Simulation of High Drag Reduction in a Turbulent Channel Flow with Polymer Additives

    NASA Technical Reports Server (NTRS)

    Dubief, Yves

    2003-01-01

    The addition of small amounts of long chain polymer molecules to wall-bounded flows can lead to dramatic drag reduction. Although this phenomenon has been known for about fifty years, the action of the polymers and its effect on turbulent structures are still unclear. Detailed experiments have characterized two distinct regimes (Warholic et al. 1999), which are referred to as low drag reduction (LDR) and high drag reduction (HDR). The first regime exhibits similar statistical trends as Newtonian flow: the log-law region of the mean velocity profile remains parallel to that of the Newtonian ow but its lower bound moves away from the wall and the upward shift of the log-region is a function of drag reduction, DR. Although streamwise fluctuations are increased and transverse ones are reduced, the shape of the rms velocity profiles is not qualitatively modified. At higher drag reductions, of the order of 40-50%, the ow enters the HDR regime for which the slope of the log-law is dramatically augmented and the Reynolds shear stress is small (Warholic et al. 1999; Ptasinski et al. 2001). The drag reduction is eventually bounded by a maximum drag reduction (MDR) (Virk & Mickley 1970) which is a function of the Reynolds number. While several experiments report mean velocity profiles very close to the empirical profile of Virk & Mickley (1970) for MDR conditions, the observations regarding the structure of turbulence can differ significantly. For instance, Warholic et al. (1999) measured a near-zero Reynolds shear stress, whereas a recent experiment (Ptasinski et al. 2001) shows evidence of non-negligible Reynolds stress in their MDR flow. To the knowledge of the authors, only the LDR regime has been documented in numerical simulations (Sureshkumar et al. 1997; Dimitropoulos et al. 1998; Min et al. 2001; Dubief & Lele 2001; Sibilla & Baron 2002). This paper discusses the simulation of polymer drag reduced channel ow at HDR using the FENE-P (Finite Elastic non

  3. Antisolvent precipitation of novel xylitol-additive crystals to engineer tablets with improved pharmaceutical performance.

    PubMed

    Kaialy, Waseem; Maniruzzaman, Mohammad; Shojaee, Saeed; Nokhodchi, Ali

    2014-12-30

    The purpose of this work was to develop stable xylitol particles with modified physical properties, improved compactibility and enhanced pharmaceutical performance without altering polymorphic form of xylitol. Xylitol was crystallized using antisolvent crystallization technique in the presence of various hydrophilic polymer additives, i.e., polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) at a range of concentrations. The crystallization process did not influence the stable polymorphic form or true density of xylitol. However, botryoidal-shaped crystallized xylitols demonstrated different particle morphologies and lower powder bulk and tap densities in comparison to subangular-shaped commercial xylitol. Xylitol crystallized without additive and xylitol crystallized in the presence of PVP or PVA demonstrated significant improvement in hardness of directly compressed tablets; however, such improvement was observed to lesser extent for xylitol crystallized in the presence of PEG. Crystallized xylitols produced enhanced dissolution profiles for indomethacin in comparison to original xylitol. The influence of additive concentration on tablet hardness was dependent on the type of additive, whereas an increased concentration of all additives provided an improvement in the dissolution behavior of indomethacin. Antisolvent crystallization using judiciously selected type and concentration of additive can be a potential approach to prepare xylitol powders with promising physicomechanical and pharmaceutical properties.

  4. Ammonium Bicarbonate Addition Improves the Detection of Proteins by Desorption Electrospray Ionization Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Honarvar, Elahe; Venter, Andre R.

    2017-03-01

    The analysis of protein by desorption electrospray ionization mass spectrometry (DESI-MS) is considered impractical due to a mass-dependent loss in sensitivity with increase in protein molecular weights. With the addition of ammonium bicarbonate to the DESI-MS analysis the sensitivity towards proteins by DESI was improved. The signal to noise ratio (S/N) improvement for a variety of proteins increased between 2- to 3-fold relative to solvent systems containing formic acid and more than seven times relative to aqueous methanol spray solvents. Three methods for ammonium bicarbonate addition during DESI-MS were investigated. The additive delivered improvements in S/N whether it was mixed with the analyte prior to sample deposition, applied over pre-prepared samples, or simply added to the desorption spray solvent. The improvement correlated well with protein pI but not with protein size. Other ammonium or bicarbonate salts did not produce similar improvements in S/N, nor was this improvement in S/N observed for ESI of the same samples. As was previously described for ESI, DESI also caused extensive protein unfolding upon the addition of ammonium bicarbonate.

  5. An improved scheme for classifying susceptibility to preferential flow

    NASA Astrophysics Data System (ADS)

    Moeys, Julien; Koestel, John; Hollis, John M.; Jarvis, Nicholas J.

    2010-05-01

    The ability to reliably predict the occurrence and strength of preferential flow in different soils and land use systems would be of great benefit in environmental planning and management at multiple spatial scales, from field to catchments and regions. We recently proposed a simple classification scheme for predicting the susceptibility of soil horizons and pedons to macropore flow, designed to support predictive modelling (Jarvis N.J. et al., 2009. A conceptual model of soil susceptibility to macropore flow. Vadose Zone Journal, 8: 902-910). The scheme, which takes the form of a decision tree, was successfully validated against a small dataset of solute transport experiments. However, in its present form, it is strongly biased toward European agricultural soils, since it was developed to support pesticide risk assessment in the EU. In this poster, we propose an improved version of the classification scheme, which is much broader in scope, with relevance for a much wider range of soils worldwide, including those with clay mineralogies that limit the development of soil macro-structure and restrict macropore flow (e.g. Ferralsols and Andosols). The new scheme is tested in a literature meta-analysis exercise, making use of the temporal moments of solute breakthrough curves derived from fits of the mobile / immobile model to steady-state experiments on short laboratory columns.

  6. Improved Respiratory Navigator Gating for Thoracic 4D flow MRI

    PubMed Central

    van Ooij, Pim; Semaan, Edouard; Schnell, Susanne; Giri, Shivraman; Stankovic, Zoran; Carr, James; Barker, Alex J.; Markl, Michael

    2016-01-01

    Background Thoracic and abdominal 4D flow MRI is typically acquired in combination with navigator respiration control which can result in highly variable scan efficiency (Seff) and thus total scan time due to inter-individual variability in breathing patterns. The aim of this study was to test the feasibility of an improved respiratory control strategy based on diaphragm navigator gating with fixed Seff, respiratory driven phase encoding, and a navigator training phase. Methods 4D flow MRI of the thoracic aorta was performed in 10 healthy subjects at 1.5T and 3T systems for the in-vivo assessment of aortic time-resolved 3D blood flow velocities. For each subject, four 4D flow scans (1: conventional navigator gating, 2–4: new implementation with fixed Seff =60%, 80% and 100%) were acquired. Data analysis included semi-quantitative evaluation of image quality of the 4D flow magnitude images (image quality grading on a four point scale), 3D segmentation of the thoracic aorta, and voxel-by-voxel comparisons of systolic 3D flow velocity vector fields between scans. Results Conventional navigator gating resulted in variable Seff = 74±13% (range = 56% – 100%) due to inter-individual variability of respiration patterns. For scans 2–4, the the new navigator implementation was able to achieve predictable total scan times with stable Seff, only depending on heart rate. Semi- and fully quantitative analysis of image quality in 4D flow magnitude images was similar for the new navigator scheme compared to conventional navigator gating. For aortic systolic 3D velocities, good agreement was found between all new navigator settings (scan 2–4) with the conventional navigator gating (scan 1) with best performance for Seff = 80% (mean difference = −0.01; limits od agreement = 0.23, Pearson’s ρ=0.89, p <0.001). No significant differences for image quality or 3D systolic velocities were found for 1.5T compared to 3T. Conclusions The findings of this study demonstrate the

  7. Heat transfer and material flow during laser assisted multi-layer additive manufacturing

    SciTech Connect

    Manvatkar, V.; De, A.; DebRoy, T.

    2014-09-28

    A three-dimensional, transient, heat transfer, and fluid flow model is developed for the laser assisted multilayer additive manufacturing process with coaxially fed austenitic stainless steel powder. Heat transfer between the laser beam and the powder particles is considered both during their flight between the nozzle and the growth surface and after they deposit on the surface. The geometry of the build layer obtained from independent experiments is compared with that obtained from the model. The spatial variation of melt geometry, cooling rate, and peak temperatures is examined in various layers. The computed cooling rates and solidification parameters are used to estimate the cell spacings and hardness in various layers of the structure. Good agreement is achieved between the computed geometry, cell spacings, and hardness with the corresponding independent experimental results.

  8. Large Structures of Drag-Reducing Pipe Flow by Surfactant Additives

    NASA Astrophysics Data System (ADS)

    Kishita, Yuki; Naka, Yoshitsugu; Minamoto, Yuki; Shimura, Masayasu; Tanahashi, Mamoru

    2016-11-01

    Characteristics of drag-reducing turbulent pipe flows with surfactant additives have been investigated using stereoscopic particle image velocimetry. Measurements have been performed for a case with surfactant solution of 150 ppm at different Reynolds numbers: Red = 31254 , 58268 , t 85556 , around the maximum drag-reduction. Two distinct peaks are observed in streamwise velocity fluctuations around y / R = 0 . 07 , 0 . 25 and weak peaks are observed in radial velocity fluctuations at the same locations, where the Reynolds shear stress is negative. The deviations toward uz' > 0 , ur' > 0 are observed at y / R = 0 . 215 , and these components are proved to contribute to the negative Reynolds stress. Drag reducing turbulent structures are investigated by means of snapshot POD analysis. The most energetic POD modes show flat periodic structures along the wall, and such structures indicate the relation with these fluctuation peaks and negative Reynolds shear stress.

  9. Phosphazene Based Additives for Improvement of Safety and Battery Lifetimes in Lithium-Ion Batteries

    SciTech Connect

    Mason K Harrup; Kevin L Gering; Harry W Rollins; Sergiy V Sazhin; Michael T Benson; David K Jamison; Christopher J Michelbacher

    2011-10-01

    There need to be significant improvements made in lithium-ion battery technology, principally in the areas of safety and useful lifetimes to truly enable widespread adoption of large format batteries for the electrification of the light transportation fleet. In order to effect the transition to lithium ion technology in a timely fashion, one promising next step is through improvements to the electrolyte in the form of novel additives that simultaneously improve safety and useful lifetimes without impairing performance characteristics over wide temperature and cycle duty ranges. Recent efforts in our laboratory have been focused on the development of such additives with all the requisite properties enumerated above. We present the results of the study of novel phosphazene based electrolytes additives.

  10. Improving Advanced Inverter Control Convergence in Distribution Power Flow

    SciTech Connect

    Nagarajan, Adarsh; Palmintier, Bryan; Ding, Fei; Mather, Barry; Baggu, Murali

    2016-11-21

    Simulation of modern distribution system powerflow increasingly requires capturing the impact of advanced PV inverter voltage regulation on powerflow. With Volt/var control, the inverter adjusts its reactive power flow as a function of the point of common coupling (PCC) voltage. Similarly, Volt/watt control curtails active power production as a function of PCC voltage. However, with larger systems and higher penetrations of PV, this active/reactive power flow itself can cause significant changes to the PCC voltage potentially introducing oscillations that slow the convergence of system simulations. Improper treatment of these advanced inverter functions could potentially lead to incorrect results. This paper explores a simple approach to speed such convergence by blending in the previous iteration's reactive power estimate to dampen these oscillations. Results with a single large (5MW) PV system and with multiple 500kW advanced inverters show dramatic improvements using this approach.

  11. Do water-saving technologies improve environmental flows?

    NASA Astrophysics Data System (ADS)

    Batchelor, Charles; Reddy, V. Ratna; Linstead, Conor; Dhar, Murli; Roy, Sumit; May, Rebecca

    2014-10-01

    Water saving and conservation technologies (WCTs) have been promoted widely in India as a practical means of improving the water use efficiency and freeing up water for other uses (e.g. for maintaining environmental flows in river systems). However, there is increasing evidence that, somewhat paradoxically, WCTs often contribute to intensification of water use by irrigated and rainfed farming systems. This occurs when: (1) Increased crop yields are coupled with increased consumptive water use and/or (2) Improved efficiency, productivity and profitability encourages farmers to increase the area cropped and/or to adopt multiple cropping systems. In both cases, the net effect is an increase in annual evapotranspiration that, particularly in areas of increasing water scarcity, can have the trade-off of reduced environmental flows. Recognition is also increasing that the claimed water savings of many WCTs may have been overstated. The root cause of this problem lies in confusion over what constitutes real water saving at the system or basin scales. The simple fact is that some of the water that is claimed to be ‘saved’ by WCTs would have percolated into the groundwater from where it can be and often is accessed and reused. Similarly, some of the “saved” runoff can be used downstream by, for example, farmers or freshwater ecosystems. This paper concludes that, particularly in areas facing increasing water scarcity, environmental flows will only be restored and maintained if they are given explicit (rather than theoretical or notional) attention. With this in mind, a simple methodology is proposed for deciding when and where WCTs may have detrimental impacts on environmental flows.

  12. High Energy Density Additives for Hybrid Fuel Rockets to Improve Performance and Enhance Safety

    NASA Technical Reports Server (NTRS)

    Jaffe, Richard L.

    2014-01-01

    We propose a conceptual study of prototype strained hydrocarbon molecules as high energy density additives for hybrid rocket fuels to boost the performance of these rockets without compromising safety and reliability. Use of these additives could extend the range of applications for which hybrid rockets become an attractive alternative to conventional solid or liquid fuel rockets. The objectives of the study were to confirm and quantify the high enthalpy of these strained molecules and to assess improvement in rocket performance that would be expected if these additives were blended with conventional fuels. We confirmed the chemical properties (including enthalpy) of these additives. However, the predicted improvement in rocket performance was too small to make this a useful strategy for boosting hybrid rocket performance.

  13. DOD SCHOOLS: Additional Reporting Could Improve Accountability for Academic Achievement of Students with Dyslexia

    DTIC Science & Technology

    2007-12-01

    Representatives DOD SCHOOLS Additional Reporting Could Improve Accountability for Academic Achievement of Students with Dyslexia December...Could Improve Accountability for Academic Achievement of Students with Dyslexia 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...Students with Dyslexia Highlights of GAO-08-70, a report to the Chairman, Committee on Science and Technology, House of Representatives Many of our

  14. Influence of polymer additives on turbulence in von Karman swirling flow between two disks. II

    NASA Astrophysics Data System (ADS)

    Burnishev, Yuri; Steinberg, Victor

    2016-03-01

    We present the experimental studies of the influence of polymer additives on the statistical and scaling properties of the fully developed turbulent regime in a von Karman swirling flow driven either by the smooth or bladed disks using only the global measurements of torque Γ and pressure p fluctuations in water- and water-sugar-based solutions of different viscosities, or elasticity El, and different polymer concentrations ϕ as a function of Re in the same apparatus. There are three highlights achieved and reported in the paper: (i) An observation of turbulent drag reduction (TDR) at both the inertial and viscous flow forcing, in a contradiction to a currently accepted opinion that only the viscous forcing leads to TDR, and the unexpected drastic difference in the transition to the fully developed turbulent and TDR regimes in von Karman swirling flow of water-based polymer solutions depending on the way of the forcing; (ii) a continuous transition to TDR in both the normalized torque drop and the rms pressure fluctuations drop and universality in scaling behavior of Cf in an agreement with theoretical predictions; and (iii) the dramatic differences in the appearance of the frequency power spectra of Γ and in particular p due to the different ways of the forcing are also observed. We discuss and summarize further the results in accordance with these three main achievements. The main message of these studies is that both the inertial forcing and viscous forcing of von Karman swirling flow between two counter-rotating disks lead to TDR in the sharp contrast to the currently accepted opinion [O. Cadot et al., "Turbulent drag reduction in a closed flow system: Boundary layer versus bulk effects," Phys. Fluids 10, 426 (1998); D. Bonn et al., "From scale scales to large scales in three-dimensional turbulence: The effect of diluted polymers," Phys. Rev. E 47, R28 (1993); and D. Bonn et al., "Turbulent drag reduction by polymers," J. Phys.: Condens. Matter 17, S1195

  15. An improved higher order panel method for linearized supersonic flow

    NASA Technical Reports Server (NTRS)

    Ehlers, F. E.; Epton, M. A.; Johnson, F. T.; Magnus, A. E.; Rubbert, P. E.

    1978-01-01

    An improved higher order panel method for linearized supersonic flow is described. Each panel, defined by four points on the surface, is divided into eight subpanels in such a way that all subpanel and panel edges are contiguous. By prescribing a quadratic distribution of the doublet on each subpanel, the doublet strength is made strictly continuous on the paneled surface. A linear source distribution is also used. Numerical results are smoother and in better agreement with experiment than the previous method with less strict continuity. A brief discussion of superinclined panels used to eliminate interior interference in nacelles is included.

  16. A significantly improved membrane for vanadium redox flow battery

    NASA Astrophysics Data System (ADS)

    Jia, Chuankun; Liu, Jianguo; Yan, Chuanwei

    A novel sandwich-type sulfonated poly(ether ether ketone) (SPEEK)/tungstophosphoric acid (TPA)/polypropylene (PP) composite membrane for a vanadium redox flow battery (VRB) has been developed with improved properties: the permeability of vanadium ions is greatly reduced and the performance of the VRB cell is greatly increased. The membrane is based on a traditional SPEEK membrane embedded with TPA but PP is used to enhance the membrane for the first time. Although its voltage efficiency (VE) is a little lower than that of a Nafion 212 membrane, it is expected to have good prospects for VRB systems because of its low cost and good performance.

  17. Characterization of neonatal aortic cannula jet flow regimes for improved cardiopulmonary bypass.

    PubMed

    Menon, Prahlad G; Teslovich, Nikola; Chen, Chia-Yuan; Undar, Akif; Pekkan, Kerem

    2013-01-18

    During pediatric and neonatal cardiopulmonary bypass (CPB), tiny aortic outflow cannulae (2-3 mm inner diameter), with micro-scale blood-wetting features transport relatively large blood volumes (0.3 to 1.0 L/min) resulting in high blood flow velocities (2 to 5 m/s). These severe flow conditions are likely to complement platelet activation, release pro-inflammatory cytokines, and further result in vascular and blood damage. Hemodynamically efficient aortic outflow cannulae are required to provide high blood volume flow rates at low exit force. In addition, optimal aortic insertion strategies are necessary in order to alleviate hemolytic risk, post-surgical neurological complications and developmental defects, by improving cerebral perfusion in the young patient. The methodology and results presented in this study serve as a baseline for design of superior aortic outflow cannulae. In this study, direct numerical simulation (DNS) computational fluid dynamics (CFD) was employed to delineate baseline hemodynamic performance of jet wakes emanating from microCT scanned state-of-the-art pediatric cannula tips in a cuboidal test rig operating at physiologically relevant laminar and turbulent Reynolds numbers (Re: 650-2150 , steady inflow). Qualitative and quantitative validation of CFD simulated device-specific jet wakes was established using time-resolved flow visualization and particle image velocimetry (PIV). For the standard end-hole cannula tip design, blood damage indices were further numerically assessed in a subject-specific cross-clamped neonatal aorta model for different cannula insertion configurations. Based on these results, a novel diffuser type cannula tip is proposed for improved jet flow-control, decreased blood damage and exit force and increased permissible flow rates. This study also suggests that surgically relevant cannula orientation parameters such as outflow angle and insertion depth may be important for improved hemodynamic performance. The jet

  18. Improvement of casing cementation of deep and ultradeep wells. Part 2: Oilfield cements and cement additives

    NASA Astrophysics Data System (ADS)

    Arens, K. H.; Akstinat, M.

    1982-07-01

    Oilfield cements and cement additives were investigated in order to improve the casing cementation of deep and ultradeep wells. Characterization and evaluation of the main oil field cements commercially available were studied. The testing was carried out according to American Petroleum Institute API standards and nonstandardized test methods (dynamic modulus of elasticity, expansion/shrinkage), especially the rheology, thickening time and the influence of pressure, temperature and water-cement ratio, were considered. The main emphasis in the field of cement additives was on the evaluation of cement retarders for high temperatures, accelerators, and additives for cement expansion. Furthermore oil field cements were tested, and their properties are described.

  19. Improvement in properties of coal water slurry by combined use of new additive and ultrasonic irradiation.

    PubMed

    Guo, Zhaobing; Feng, Ruo; Zheng, Youfei; Fu, Xiaoru

    2007-07-01

    Coal water slurry (CWS) was prepared with a newly developed additive from naphthalene oil. The effects of ultrasonic irradiation on coal particle size distribution (PSD), adsorption behavior of additive in coal particles and the characteristics of CWS were investigated. Results showed that ultrasonic irradiation led to a higher proportion of fine coal in CWS and increased the saturated adsorption amount of additive in coal particles. In addition, the rheological behavior and static stability of CWS irradiated by ultrasonic wave were remarkably improved. The changes on viscosity of CWS containing 1% and 2% additive are qualitatively different with the increasing sonication time studied. The reason for the different effect of sonication time on CWS viscosity is presented in this study.

  20. Coating microchannels to improve Field-Flow Fractionation

    NASA Astrophysics Data System (ADS)

    Shendruk, Tyler N.; Slater, Gary W.

    2011-03-01

    We propose a selective-steric-mode Field-Flow Fractionation (ssFFF) technique for size separation of particles. Grafting a dense polymer brush onto the accumulation wall of a microchannel adds two novel effects to FFF: the particles must pay an entropic cost to enter the brush and the brush has a hydrodynamic thickness that shifts the no-slip condition. For small particles, the brush acts as a low-velocity region, leading to chromatographic-like retention. We present an analytical retention theory for small but finite-sized particles in a microchannel with a dense Alexander brush coating that possesses a well-defined hydrodynamic thickness. This theory is compared to a numerical solution for the retention ratio given by a flow approximated by the Brinkman equation and particle-brush interaction that is both osmotic and compressional. Large performance improvements are predicted in several regimes. Multi-Particle Collision simulations of the system assess the impact of factors neglected by the theory such as the dynamics of particle impingement on the brush subject to a flow.

  1. Assessment of horizontal laminar air flow instrument table for additional ultraclean space during surgery.

    PubMed

    Nilsson, K-G; Lundholm, R; Friberg, S

    2010-11-01

    The area in a vertical ultraclean laminar air flow (LAF) theatre is usually too small to accommodate all the equipment needed for major surgery. We investigated the addition of an instrument table supplied with fixed ultraclean LAF and placed alongside the existing main LAF unit, to determine its physical and bacteriological effect on the main unit. In phase 1, with two investigators but without a patient, smoke tests showed no intrusion of air from the table into the main unit and particle counts did not show any adverse effect on the main LAF unit. In phase 2, during patients undergoing two total knee replacements, the LAF table and a table without LAF were placed alongside the main LAF unit. The tables were subjected to the activity of an extra operating room (OR) nurse working from inside the main LAF vigorously simulating handling of instruments. During this activity, the >5μm particle counts were 275/m(3) at the instrument table with LAF and 8550/m(3) at the table without LAF (P<0.0001). Also, without the OR nurse activity, the particle counts, just inside the main unit and adjacent to the LAF table, were significantly reduced (P<0.03-0.003). Sedimentation plates on the LAF table and in the main unit registered 22 and 25cfu/m(2)/h respectively compared with 45cfu/m(2)/h at the instrument table without LAF. In conclusion, the results from the smoke tests, particle counts and bacteriological evaluation showed that the additional instrument table supplied with LAF is efficient and can be safely used as an extension additional to a main OR LAF unit.

  2. The Effectiveness of an Additional Stretching Exercise Program in Improving Flexibility Level among Preschool Boys

    ERIC Educational Resources Information Center

    Lee, Wee Akina Sia Seng; Rengasamy, Shabeshan A/L; Raju, Subramaniam A/L

    2014-01-01

    This study was conducted to examine the effectiveness of a two minutes' additional stretching exercise program in a 30 minutes games teaching lesson in improving the flexibility level of 6 year old preschool boys (M = 5.92, SD = 0.27) in a preschool in Malaysia. Fifty (50) preschool boys were selected for the study based on the intact sampling…

  3. Chill water additive controls transfer of Salmonella and Campylobacter by improved chlorine efficacy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In earlier work, we showed that a proprietary additive (T-128) maintains chlorine activity in the presence of organic material such as broiler parts. T-128 improves the efficacy of chlorine to control transfer of Campylobacter and Salmonella from inoculated wings to un-inoculated wings during immer...

  4. Pathways of nitrobenzene degradation in horizontal subsurface flow constructed wetlands: Effect of intermittent aeration and glucose addition.

    PubMed

    Kirui, Wesley K; Wu, Shubiao; Kizito, Simon; Carvalho, Pedro N; Dong, Renjie

    2016-01-15

    Intermittent aeration and addition of glucose were applied to horizontal subsurface flow constructed wetlands in order to investigate the effect on pathways of nitrobenzene (NB) degradation and interactions with microbial nitrogen and sulphur transformations. The experiment was carried out in three phases A, B and C consisting of different NB loading and glucose dosing. For each phase, the effect of aeration was assessed by intermittently aerating one wetland and leaving one unaerated. Regardless of whether or not the wetland was aerated, at an influent NB concentration of 140 mg/L, both wetlands significantly reduced NB to less than 2 mg/L, a reduction efficiency of 98%. However, once the influent NB concentration was increased to 280 mg/L, the aerated wetland had a higher removal performance 82% compared to that of the unaerated wetland 71%. Addition of glucose further intensified the NB removal to 95% in the aerated wetlands and 92% in the unaerated. Aeration of wetlands enhanced NB degradation, but also resulted in higher NB volatilization of 6 mg m(-2) d(-1). The detected high concentration of sulphide 20-60 mg/L in the unaerated wetland gave a strong indication that NB may act as an electron donor to sulphate-reducing bacteria, but this should be further investigated. Aeration positively improved NB removal in constructed wetlands, but resulted in higher NB volatilization. Glucose addition induced co-metabolism to enhance NB degradation.

  5. Improvement of activated sludge resistance to shock loading by fungal enzyme addition during textile wastewater treatment.

    PubMed

    Manai, Imène; Miladi, Baligh; El Mselmi, Abdellatif; Hamdi, Moktar; Bouallagui, Hassib

    2017-04-01

    The effects of the additions of the fungal enzymatic extract were investigated in relation to the treatment of real textile wastewater (RTW) by the activated sludge process (ASP). The used enzyme cocktail was produced by a new isolated fungal Chaetomium globosum IMA1. The system that was operated with enzyme addition showed a better chemical oxygen demand (COD) removal efficiency (95%) compared to the control system (75%). In addition, the improvement of color removal (OD620) efficiencies was around 15%, when the newly consortium fungal enzymes was added. As the organic loading rate (OLR) increased from 0.33 g to 0.66 g COD L(-1) d(-1), a decrease in the performance of the two reactors was observed by monitoring the quality of treated effluents. However, the ASP working with enzyme addition showed a strong resistance to shock loadings and restored after few days compared to the control system, which was strongly inhibited. In fact, the enzyme addition improved the sludge volume index (SVI) and the activity of microorganisms. A high activity of laccase (300 U.L(-1)) enzyme was observed throughout the decolorization process in the improved system.

  6. The use of Electrolyte Additives to Improve the High Temperature Resilience of Li-Ion Cells

    NASA Technical Reports Server (NTRS)

    Smart, Marshall C.; Lucht, B. L.; Ratnakumar, Bugga V.

    2007-01-01

    This viewgraph presentation reviews the use of electrolyte additves to improve the resillience of Lithium ion cells. The objective of this work is to identify lithium-ion electrolytes, which will lead to Li-ion cells with a wide operational temperature range (+60 to -60 C), and to develop Li-ion electrolytes which result in cells that display improved high temperature resilience. Significant improvement in the high temperature resilience of Li-ion cells containing these additives was observed, with the most dramatic benefit being displayed by addition of DMAc. When the electrochemical properties of the individual electrodes were analyzed, the degradation of the anode kinetics was slowed most dramatically by the incorporation of DMAc into the electrolytes. Whereas, the greatest retention in the cathode kinetics was observed in the cell containing the electrolyte with VC added.

  7. Improved performance of air-cathode microbial fuel cell through additional Tween 80

    NASA Astrophysics Data System (ADS)

    Wen, Qing; Kong, Fanying; Ma, Fang; Ren, Yueming; Pan, Zhongcheng

    The ability of electron transfer from microbe cell to anode electrode plays a key role in microbial fuel cell (MFC). This study explores a new approach to improve the MFC performance and electron transfer rate through addition of Tween 80. Results demonstrate that, for an air-cathode MFC operating on 1 g L -1 glucose, when the addition of Tween 80 increases from 0 to 80 mg L -1, the maximum power density increases from 21.5 to 187 W m -3 (0.6-5.2 W m -2), the corresponding current density increases from 1.8 to 17 A m -2, and the resistance of MFC decreases from 27.0 to 5.7 Ω. Electrochemical impedance spectroscopy (EIS) analysis suggests that the improvement of overall performance of the MFC can be attributed to the addition of Tween 80. The high power density achieved here may be due to the increase of permeability of cell membranes by addition of Tween 80, which reduces the electron transfer resistance through the cell membrane and increases the electron transfer rate and number, consequently enhances the current and power output. A promising way of utilizing surfactant to improve energy generation of MFC is demonstrated.

  8. Evaluating mixtures of 14 hygroscopic additives to improve antibody microarray performance.

    PubMed

    Bergeron, Sébastien; Laforte, Veronique; Lo, Pik-Shan; Li, Huiyan; Juncker, David

    2015-11-01

    Microarrays allow the miniaturization and multiplexing of biological assays while only requiring minute amounts of samples. As a consequence of the small volumes used for spotting and the assays, evaporation often deteriorates the quality, reproducibility of spots, and the overall assay performance. Glycerol is commonly added to antibody microarray printing buffers to decrease evaporation; however, it often decreases the binding of antibodies to the surface, thereby negatively affecting assay sensitivity. Here, combinations of 14 hygroscopic chemicals were used as additives to printing buffers for contact-printed antibody microarrays on four different surface chemistries. The ability of the additives to suppress evaporation was quantified by measuring the residual buffer volume in open quill pins over time. The seven best additives were then printed either individually or as a 1:1 mixture of two additives, and the homogeneity, intensity, and reproducibility of both the spotted protein and of a fluorescently labeled analyte in an assay were quantified. Among the 28 combinations on the four slides, many were found to outperform glycerol, and the best additive mixtures were further evaluated by changing the ratio of the two additives. We observed that the optimal additive mixture was dependent on the slide chemistry, and that it was possible to increase the binding of antibodies to the surface threefold compared to 50 % glycerol, while decreasing whole-slide coefficient of variation to 5.9 %. For the two best slides, improvements were made for both the limit of detection (1.6× and 5.9×, respectively) and the quantification range (1.2× and 2.1×, respectively). The additive mixtures identified here thus help improve assay reproducibility and performance, and might be beneficial to all types of microarrays that suffer from evaporation of the printing buffers.

  9. Source Distribution Method for Unsteady One-Dimensional Flows With Small Mass, Momentum, and Heat Addition and Small Area Variation

    NASA Technical Reports Server (NTRS)

    Mirels, Harold

    1959-01-01

    A source distribution method is presented for obtaining flow perturbations due to small unsteady area variations, mass, momentum, and heat additions in a basic uniform (or piecewise uniform) one-dimensional flow. First, the perturbations due to an elemental area variation, mass, momentum, and heat addition are found. The general solution is then represented by a spatial and temporal distribution of these elemental (source) solutions. Emphasis is placed on discussing the physical nature of the flow phenomena. The method is illustrated by several examples. These include the determination of perturbations in basic flows consisting of (1) a shock propagating through a nonuniform tube, (2) a constant-velocity piston driving a shock, (3) ideal shock-tube flows, and (4) deflagrations initiated at a closed end. The method is particularly applicable for finding the perturbations due to relatively thin wall boundary layers.

  10. Assessing the potential for improved scramjet performance through application of electromagnetic flow control

    NASA Astrophysics Data System (ADS)

    Lindsey, Martin Forrester

    Sustained hypersonic flight using scramjet propulsion is the key technology bridging the gap between turbojets and the exoatmospheric environment where a rocket is required. Recent efforts have focused on electromagnetic (EM) flow control to mitigate the problems of high thermomechanical loads and low propulsion efficiencies associated with scramjet propulsion. This research effort is the first flight-scale, three-dimensional computational analysis of a realistic scramjet to determine how EM flow control can improve scramjet performance. Development of a quasi-one dimensional design tool culminated in the first open source geometry of an entire scramjet flowpath. This geometry was then tested extensively with the Air Force Research Laboratory's three-dimensional Navier-Stokes and EM coupled computational code. As part of improving the model fidelity, a loosely coupled algorithm was developed to incorporate thermochemistry. This resulted in the only open-source model of fuel injection, mixing and combustion in a magnetogasdynamic (MGD) flow controlled engine. In addition, a control volume analysis tool with an electron beam ionization model was presented for the first time in the context of the established computational method used. Local EM flow control within the internal inlet greatly impacted drag forces and wall heat transfer but was only marginally successful in raising the average pressure entering the combustor. The use of an MGD accelerator to locally increase flow momentum was an effective approach to improve flow into the scramjet's isolator. Combustor-based MGD generators proved superior to the inlet generator with respect to power density and overall engine efficiency. MGD acceleration was shown to be ineffective in improving overall performance, with all of the bypass engines having approximately 33% more drag than baseline and none of them achieving a self-powered state.

  11. Size characterization by Sedimentation Field Flow Fractionation of silica particles used as food additives.

    PubMed

    Contado, Catia; Ravani, Laura; Passarella, Martina

    2013-07-25

    Four types of SiO2, available on the market as additives in food and personal care products, were size characterized using Sedimentation Field Flow Fractionation (SdFFF), SEM, TEM and Photon Correlation Spectroscopy (PCS). The synergic use of the different analytical techniques made it possible, for some samples, to confirm the presence of primary nanoparticles (10 nm) organized in clusters or aggregates of different dimension and, for others, to discover that the available information is incomplete, particularly that regarding the presence of small particles. A protocol to extract the silica particles from a simple food matrix was set up, enriching (0.25%, w w(-1)) a nearly silica-free instant barley coffee powder with a known SiO2 sample. The SdFFF technique, in conjunction with SEM observations, made it possible to identify the added SiO2 particles and verify the new particle size distribution. The SiO2 content of different powdered foodstuffs was determined by graphite furnace atomic absorption spectroscopy (GFAAS); the concentrations ranged between 0.006 and 0.35% (w w(-1)). The protocol to isolate the silica particles was so applied to the most SiO2-rich commercial products and the derived suspensions were separated by SdFFF; SEM and TEM observations supported the size analyses while GFAAS determinations on collected fractions permitted element identification.

  12. An experimental survey of additives for improving dehydrogenation properties of magnesium hydride

    NASA Astrophysics Data System (ADS)

    Zhou, Chengshang; Fang, Zhigang Zak; Sun, Pei

    2015-03-01

    The use of a wide range of additives has been known as an important method for improving hydrogen storage properties of MgH2. There is a lack of a standard methodology, however, that can be used to select or compare the effectiveness of different additives. A systematic experimental survey was carried out in this study to compare a wide range of additives including transitions metals, transition metal oxides, hydrides, intermetallic compounds, and carbon materials, with respect to their effects on dehydrogenation properties of MgH2. MgH2 with various additives were prepared by using a high-energy-high-pressure planetary ball milling method and characterized by using thermogravimetric analysis (TGA) techniques. The results showed that additives such as Ti and V-based metals, hydride, and certain intermetallic compounds have strong catalytic effects. Additives such as Al, In, Sn, Si showed minor effects on the kinetics of the dehydrogenation of MgH2, while exhibiting moderate thermodynamic destabilizing effects. In combination, MgH2 with both kinetic and thermodynamic additives, such as the MgH2-In-TiMn2 system, exhibited a drastically decreased dehydrogenation temperature.

  13. Addition of HOBt improves the conversion of thioester-Amine chemical ligation.

    PubMed

    Todorovski, Toni; Suñol, David; Riera, Antoni; Macias, Maria J

    2015-11-01

    The syntheses of large peptides and of those containing non-natural amino acids can be facilitated by the application of convergent approaches, dissecting the native sequence into segments connected through a ligation reaction. We describe an improvement of the ligation protocol used to prepare peptides and proteins without cysteine residues at the ligation junction. We have found that the addition of HOBt to the ligation, improves the conversion of the ligation reaction without affecting the epimerization rate or chemoselectivity, and it can be efficiently used with peptides containing phosphorylated amino acids.

  14. An improved source flow characteristic technique for the analysis of scramjet exhaust flow fields

    NASA Technical Reports Server (NTRS)

    Delguidice, P. D.; Dash, S.

    1975-01-01

    The process is discussed of designing a nozzle for a hypersonic airbreathing vehicle which involves a complex study of the inter-relationship among many parameters: internal-external expansion, vehicle lift, drag, pitching moments, and structural and weight limitations. The source flow characteristic approach to the design process was extended and improved, and streamline interpolation procedure was incorporated. All characteristic and boundary calculations were made compatible with frozen, equilibrium and ideal gas thermodynamic options, while slip surface calculations (cowl interaction) were extended to underexpanded flow conditions. Since viscous forces can significantly influence vehicle forces, pitching moments and structural/weight considerations, a local integration via flat plate boundary layer skin friction and heat transfer coefficients was included. These effects are calculated using the Spalding and Chi method, and all force and moment calculations are performed via integration of the local forces acting on the specified vehicle wetted areas.

  15. An Improved Lattice Boltzmann Model for Non-Newtonian Flows with Applications to Solid-Fluid Interactions in External Flows

    NASA Astrophysics Data System (ADS)

    Adam, Saad; Premnath, Kannan

    2016-11-01

    Fluid mechanics of non-Newtonian fluids, which arise in numerous settings, are characterized by non-linear constitutive models that pose certain unique challenges for computational methods. Here, we consider the lattice Boltzmann method (LBM), which offers some computational advantages due to its kinetic basis and its simpler stream-and-collide procedure enabling efficient simulations. However, further improvements are necessary to improve its numerical stability and accuracy for computations involving broader parameter ranges. Hence, in this study, we extend the cascaded LBM formulation by modifying its moment equilibria and relaxation parameters to handle a variety of non-Newtonian constitutive equations, including power-law and Bingham fluids, with improved stability. In addition, we include corrections to the moment equilibria to obtain an inertial frame invariant scheme without cubic-velocity defects. After preforming its validation study for various benchmark flows, we study the physics of non-Newtonian flow over pairs of circular and square cylinders in a tandem arrangement, especially the wake structure interactions and their effects on resulting forces in each cylinder, and elucidate the effect of the various characteristic parameters.

  16. Improvement of mechanical properties by additive assisted laser sintering of PEEK

    SciTech Connect

    Kroh, M. Bonten, C.; Eyerer, P.

    2014-05-15

    The additive assisted laser sintering was recently developed at IKT: A carbon black (CB) additive is used to adjust the polymer's laser absorption behavior with the aim to improve the interconnection of sintered powder layers. In this paper a parameter study, Polyetheretherketone (PEEK) samples were prepared with different contents of carbon black and were laser sintered with varying thermal treatment. The samples were mechanically tested and investigated by optical light and transmission electron microscopy. An influence on the morphology at the border areas of particles and intersections of laser sintered layers was found. Depending on the viscosity of the raw material and CB content, different shapes of lamellae were observed. These (trans-) crystalline or polymorph structures, respectively, influence the thermal and mechanical behavior of the virgin PEEK. Moreover, the thermal treatment during the sintering process caused an improvement of mechanical properties like tensile strength and elongation at break.

  17. Macrosegregation Improvement by Swirling Flow Nozzle for Bloom Continuous Castings

    NASA Astrophysics Data System (ADS)

    Sun, Haibo; Zhang, Jiaquan

    2014-06-01

    Based on mathematical model coupling electromagnetism, fluid flow, heat transfer, and solute transport, the metallurgical performances of conventional straight nozzle, swirling flow nozzle (SFN), and M-EMS have been evaluated and compared. The soundness improvement of bloom castings has been investigated by casting tests of adopting the newly designed SFN. As compared to the normal nozzle, center porosity has been eliminated along with the popular center radial crack, and a better chemical homogeneity was obtained by employing the SFN accordingly, where the maximum segregation degree of C and S at the strand cross section is decreased from 1.28 to 1.02 and from 1.32 to 1.06, respectively. Combined with the results of numerical simulation, the positive effect obtained can be attributed to the remarkable superheat dissipation under the implementation of SFN, where, compared with the normal nozzle, the melt superheat degree at the mold exit is reduced by 15.5 K, 9.8 K, and 17.3 K (15.5 °C, 9.8 °C, and 17.3 °C) under the other three casting measures of SFN, normal nozzle with M-EMS, and SFN with M-EMS, respectively.

  18. Improved Li-TiS2 cell cycling in ether-based electrolytes with synergistic additives

    NASA Technical Reports Server (NTRS)

    Shen, D. H.; Subbarao, S.; Deligiannis, F.; Huang, C.-K.; Halpert, G.; Dominey, L.; Koch, V. R.; Goldman, J.

    1991-01-01

    Results of the application of 2-MeF and KOH additives to improve the lithium stability in THF, dioxolane, and THF/2-MeTHF solvent-based electrolytes are presented. The stability of these electrolytes with and without additives is evaluated by microcalorimetry and AC impedance spectroscopy. A novel method, cathode turnover number, is proposed to represent the electrolyte performance in a given system. The lithium cycling efficiency and cathode turnover number of the electrolytes are calculated from the cycle life data in experimental Li-TiS2 cells. Overall, THF/2-MeTHF electrolyte containing 2-MeF and/or KOH exhibited higher stability, lithium cycling efficiency, and cathode turnover number compared to THF and dioxolane electrolytes with and without additives.

  19. HEAT: High accuracy extrapolated ab initio thermochemistry. III. Additional improvements and overview.

    SciTech Connect

    Harding, M. E.; Vazquez, J.; Ruscic, B.; Wilson, A. K.; Gauss, J.; Stanton, J. F.; Chemical Sciences and Engineering Division; Univ. t Mainz; The Univ. of Texas; Univ. of North Texas

    2008-01-01

    Effects of increased basis-set size as well as a correlated treatment of the diagonal Born-Oppenheimer approximation are studied within the context of the high-accuracy extrapolated ab initio thermochemistry (HEAT) theoretical model chemistry. It is found that the addition of these ostensible improvements does little to increase the overall accuracy of HEAT for the determination of molecular atomization energies. Fortuitous cancellation of high-level effects is shown to give the overall HEAT strategy an accuracy that is, in fact, higher than most of its individual components. In addition, the issue of core-valence electron correlation separation is explored; it is found that approximate additive treatments of the two effects have limitations that are significant in the realm of <1 kJ mol{sup -1} theoretical thermochemistry.

  20. Addition of Improved Shock-Capturing Schemes to OVERFLOW 2.1

    NASA Technical Reports Server (NTRS)

    Burning, Pieter G.; Nichols, Robert H.; Tramel, Robert W.

    2009-01-01

    Existing approximate Riemann solvers do not perform well when the grid is not aligned with strong shocks in the flow field. Three new approximate Riemann algorithms are investigated to improve solution accuracy and stability in the vicinity of strong shocks. The new algorithms are compared to the existing upwind algorithms in OVERFLOW 2.1. The new algorithms use a multidimensional pressure gradient based switch to transition to a more numerically dissipative algorithm in the vicinity of strong shocks. One new algorithm also attempts to artificially thicken captured shocks in order to alleviate the errors in the solution introduced by "stair-stepping" of the shock resulting from the approximate Riemann solver. This algorithm performed well for all the example cases and produced results that were almost insensitive to the alignment of the grid and the shock.

  1. Improving green waste composting by addition of sugarcane bagasse and exhausted grape marc.

    PubMed

    Zhang, Lu; Sun, Xiangyang

    2016-10-01

    The composting of lignocellulosic waste into compost is a potential way of sustainably disposing of a waste while generating a useful product. The current study determined whether the addition of sugarcane bagasse (SCB) (at 0, 15, and 25%) and/or exhausted grape marc (EGM) (at 0, 10, and 20%) improved the two-stage composting of green waste (GW). The combined addition of SCB and EGM improved composting conditions and the quality of the compost product in terms of temperature, water-holding capacity, particle-size distribution, coarseness index, pH, electrical conductivity, water-extractable organic carbon and nitrogen, microbial numbers, enzymatic activities, polysaccharide and lignin content, nutrient content, respiration, and phytotoxicity. The optimal two-stage composting and the best quality compost were obtained with the combined addition of 15% SCB and 20% EGM. With the optimized two-stage composting method, the compost matured in only 21days rather than in the 90-270days required for traditional composting.

  2. Addition of Carbon to the Culture Medium Improves the Detection Efficiency of Aflatoxin Synthetic Fungi

    PubMed Central

    Suzuki, Tadahiro; Iwahashi, Yumiko

    2016-01-01

    Aflatoxin (AF) is a harmful secondary metabolite that is synthesized by the Aspergillus species. Although AF detection techniques have been developed, techniques for detection of AF synthetic fungi are still required. Techniques such as plate culture methods are continually being modified for this purpose. However, plate culture methods require refinement because they suffer from several issues. In this study, activated charcoal powder (carbon) was added to a culture medium containing cyclodextrin (CD) to enhance the contrast of fluorescence and improve the detection efficiency for AF synthetic fungi. Two culture media, potato dextrose agar and yeast extract sucrose agar, were investigated using both plate and liquid cultures. The final concentrations of CD and carbon in the media were 3 mg/mL and 0.3 mg/mL, respectively. Addition of carbon improved the visibility of fluorescence by attenuating approximately 30% of light scattering. Several fungi that could not be detected with only CD in the medium were detected with carbon addition. The carbon also facilitated fungal growth in the potato dextrose liquid medium. The results suggest that addition of carbon to media can enhance the observation of AF-derived fluorescence. PMID:27854283

  3. Combining phytoextraction and biochar addition improves soil biochemical properties in a soil contaminated with Cd.

    PubMed

    Lu, Huanping; Li, Zhian; Fu, Shenglei; Méndez, Ana; Gascó, Gabriel; Paz-Ferreiro, Jorge

    2015-01-01

    The main goal of phytoremediation is to improve ecosystem functioning. Soil biochemical properties are considered as effective indicators of soil quality and are sensitive to various environmental stresses, including heavy metal contamination. The biochemical response in a soil contaminated with cadmium was tested after several treatments aimed to reduce heavy metal availability including liming, biochar addition and phytoextraction using Amaranthus tricolor L. Two biochars were added to the soil: eucalyptus pyrolysed at 600 °C (EB) and poultry litter at 400 °C (PLB). Two liming treatments were chosen with the aim of bringing soil pH to the same values as in the treatments EB and PLB. The properties studied included soil microbial biomass C, soil respiration and the activities of invertase, β-glucosidase, β-glucosaminidase, urease and phosphomonoesterase. Both phytoremediation and biochar addition improved soil biochemical properties, although results were enzyme specific. For biochar addition these changes were partly, but not exclusively, mediated by alterations in soil pH. A careful choice of biochar must be undertaken to optimize the remediation process from the point of view of metal phytoextraction and soil biological activity.

  4. Improved surface property of PVDF membrane with amphiphilic zwitterionic copolymer as membrane additive

    NASA Astrophysics Data System (ADS)

    Li, Jian-Hua; Li, Mi-Zi; Miao, Jing; Wang, Jia-Bin; Shao, Xi-Sheng; Zhang, Qi-Qing

    2012-06-01

    An attempt to improve hydrophilicity and anti-fouling properties of PVDF membranes, a novel amphiphilic zwitterionic copolymer poly(vinylidene fluoride)-graft-poly(sulfobetaine methacrylate) (PVDF-g-PSBMA) was firstly synthesized by atom transfer radical polymerization (ATRP) and used as amphiphilic copolymer additive in the preparation of PVDF membranes. The PVDF-g-PSBMA/PVDF blend membranes were prepared by immersion precipitation process. Fourier transform infrared attenuated reflection spectroscopy (FTIR-ATR) and X-ray photoelectronic spectroscopy (XPS) measurements confirmed that PSBMA brushes from amphiphilic additives were preferentially segregated to membrane-coagulant interface during membrane formation. The morphology of membranes was characterized by scanning electron microscopy (SEM). Water contact angle measurements showed that the surface hydrophilicity of PVDF membranes was improved significantly with the increasing of amphiphilic copolymer PVDF-g-PSBMA in cast solution. Protein static adsorption experiment and dynamic fouling resistance experiment revealed that the surface enrichment of PSBMA brush endowed PVDF blend membrane great improvement of surface anti-fouling ability.

  5. Solution of plane cascade flow using improved surface singularity methods

    NASA Technical Reports Server (NTRS)

    Mcfarland, E. R.

    1981-01-01

    A solution method has been developed for calculating compressible inviscid flow through a linear cascade of arbitrary blade shapes. The method uses advanced surface singularity formulations which were adapted from those found in current external flow analyses. The resulting solution technique provides a fast flexible calculation for flows through turbomachinery blade rows. The solution method and some examples of the method's capabilities are presented.

  6. Sugar additives improve signal fidelity for implementing two-phase resorufin-based enzyme immunoassays.

    PubMed

    Sandoz, Patrick A; Chung, Aram J; Weaver, Westbrook M; Di Carlo, Dino

    2014-06-17

    Enzymatic signal amplification based on fluorogenic substrates is commonly used for immunoassays; however, when transitioning these assays to a digital format in water-in-mineral oil emulsions, such amplification methods have been limited by the leakage of small reporting fluorescent probes. In the present study, we used a microfluidic system to study leakage from aqueous droplets in a controlled manner and confirmed that the leakage of fluorescent resorufin derivatives is mostly due to the presence of the lipophilic surfactant Span80, which is commonly used to preserve emulsion stability. This leakage can be overcome by the addition of specific sugars that most strongly interfered with the surfactants ability to form micelles in water. The application of the microfluidic system to the quantitative analysis of droplets and the implementation of the described sugar additives would allow for alternatives to fluorinated surfactant-based platforms and improve the signal fidelity in enzyme immunoassays implemented through multiphase microfluidics.

  7. Integrated reservoir characterization: Improvement in heterogeneities stochastic modelling by integration of additional external constraints

    SciTech Connect

    Doligez, B.; Eschard, R.; Geffroy, F.

    1997-08-01

    The classical approach to construct reservoir models is to start with a fine scale geological model which is informed with petrophysical properties. Then scaling-up techniques allow to obtain a reservoir model which is compatible with the fluid flow simulators. Geostatistical modelling techniques are widely used to build the geological models before scaling-up. These methods provide equiprobable images of the area under investigation, which honor the well data, and which variability is the same than the variability computed from the data. At an appraisal phase, when few data are available, or when the wells are insufficient to describe all the heterogeneities and the behavior of the field, additional constraints are needed to obtain a more realistic geological model. For example, seismic data or stratigraphic models can provide average reservoir information with an excellent areal coverage, but with a poor vertical resolution. New advances in modelisation techniques allow now to integrate this type of additional external information in order to constrain the simulations. In particular, 2D or 3D seismic derived information grids, or sand-shale ratios maps coming from stratigraphic models can be used as external drifts to compute the geological image of the reservoir at the fine scale. Examples are presented to illustrate the use of these new tools, their impact on the final reservoir model, and their sensitivity to some key parameters.

  8. Experimental Evaluation of Oxide Nanoparticles as Friction and Wear Improvement Additives in Motor Oil

    DOE PAGES

    Demas, Nicholaos G.; Erck, Robert A.; Lorenzo-Martin, Cinta; ...

    2017-01-01

    The effect of two nanoparticle oxides on friction and wear was studied under laboratory test conditions using a reciprocating test machine and two test configurations. The addition of these nanoparticles in base stock oil under certain conditions reduced the coefficient of friction and improved wear, but that depended on the test configuration. Examination of the rubbed surfaces showed the pronounced formation of a tribofilm in some cases, while polishing on the surface was also observed in other cases. Contact configuration is important when oxide nanoparticles are being evaluated and the conclusions about their efficacy can be vastly different.

  9. On the asymptotic improvement of supervised learning by utilizing additional unlabeled samples - Normal mixture density case

    NASA Technical Reports Server (NTRS)

    Shahshahani, Behzad M.; Landgrebe, David A.

    1992-01-01

    The effect of additional unlabeled samples in improving the supervised learning process is studied in this paper. Three learning processes. supervised, unsupervised, and combined supervised-unsupervised, are compared by studying the asymptotic behavior of the estimates obtained under each process. Upper and lower bounds on the asymptotic covariance matrices are derived. It is shown that under a normal mixture density assumption for the probability density function of the feature space, the combined supervised-unsupervised learning is always superior to the supervised learning in achieving better estimates. Experimental results are provided to verify the theoretical concepts.

  10. Nanoparticle delivery of chemosensitizers improve chemotherapy efficacy without incurring additional toxicity

    NASA Astrophysics Data System (ADS)

    Caster, Joseph M.; Sethi, Manish; Kowalczyk, Sonya; Wang, Edina; Tian, Xi; Nabeel Hyder, Sayed; Wagner, Kyle T.; Zhang, Ying-Ao; Kapadia, Chintan; Man Au, Kin; Wang, Andrew Z.

    2015-01-01

    Chemosensitizers can improve the therapeutic index of chemotherapy and overcome treatment resistance. Successful translation of chemosensitizers depends on the development of strategies that can preferentially deliver chemosensitizers to tumors while avoiding normal tissue. We hypothesized that nanoparticle (NP) formulation of chemosensitizers can improve their delivery to tumors which can in turn improve their therapeutic index. To demonstrate the proof of principle of this approach, we engineered NP formulations of two chemosensitizers, the PI3-kindase inhibitor wortmanin (Wtmn) and the PARP inhibitor olaparib. NP Wtmn and NP olaparib were evaluated as chemosensitizers using lung cancer cells and breast cancer cells respectively. We found Wtmn to be an efficient chemosensitizer in all tested lung-cancer cell lines reducing tumor cell growth between 20 and 60% compared to drug alone. NP formulation did not decrease its efficacy in vitro. Olaparib showed less consistent chemosensitization as a free drug or in NP formulation. NP Wtmn was further evaluated as a chemosensitizer using mouse models of lung cancer. We found that NP Wtmn is an effective chemosensitizer and more effective than free Wtmn showing a 32% reduction in tumor growth compared to free Wtmn when given with etoposide. Importantly, NP Wtmn was able to sensitize the multi-drug resistant H69AR cells to etoposide. Additionally, the combination of NP Wtmn and etoposide chemotherapy did not significantly increase toxicity. The present study demonstrates the proof of principle of using NP formulation of chemosensitizing drugs to improve the therapeutic index of chemotherapy.

  11. Does performing drop jumps with additional eccentric loading improve jump performance?

    PubMed

    Aboodarda, Saied J; Byrne, Jeannette M; Samson, Michael; Wilson, Barry D; Mokhtar, Abdul H; Behm, David G

    2014-08-01

    Previous investigators have speculated that applying additional external load throughout the eccentric phase of the jumping movement could amplify the stretch-shortening cycle mechanism and modulate jumping performance and jump exercise intensity. The aims of this study, therefore, were to determine the effect of increased eccentric phase loading, as delivered using an elastic device, on drop jumps (DJs) performed from different drop heights. Of specific interest were changes in (a) the kinetics; eccentric and concentric impulse, rate of force development (RFD), concentric velocity and (b) the electromyographic (EMG) activity of leg muscles. In a randomized repeated-measure study, 15 highly resistance trained male subjects performed DJs from 3 heights (20, 35, and 50 cm) under 3 different conditions: body weight only (free DJ) and with elastic bands providing downward force equivalent to 20% (+20% DJ) and 30% (+30% DJ) of body mass. All DJs were recorded using video and force plate data that were synchronized with EMG data. Results demonstrated that using additional tensile load during the airborne and eccentric phases of the DJ could enhance eccentric impulse (p = 0.042) and RFD (p < 0.001) and resulted in small to moderate effect size (ES) increases in quadriceps intergrated EMG across the eccentric phase (0.23 > ES > 0.51). The observed greater eccentric loading, however, did not immediately alter concentric kinetics and jump height nor did it alter muscle activation levels during this phase. The findings indicated that, in addition to the conventional technique of increasing drop height, using a tensile load during the airborne and eccentric phases of the DJ could further improve eccentric loading of DJs. As it has been suggested that eccentric impulse and RFD are indicators of DJ exercise intensity, these findings suggest that the loaded DJs, using additional elastic load, may be an effective technique for improving DJ exercise intensity without acute effects

  12. An isothermal flowmeter with improved frequency response for measuring tissue blood flow.

    PubMed

    Olshausen, K; Gross, R; Kirchheim, H

    1976-11-30

    An isothermal flowmeter with improved frequency response for measuring tissue blood flow was developed using thermistors. Direct heating of the thermistors allows a simple construction of small (0.5 mm outer diameter) capillary probes which do not require any additional heating coil. The changes of a feedback current necessary to keep the thermistor at a constant increment above tissue temperature indicate tissue blood flow; a second thermistor compensates variations of tissue temperature. The dynamic performance of the device shows a low-pass characteristic with a cut-off frequency higher than 5 Hz. For low flow rates the output signal was found to be proportional to the flow; for higher flow rates a linearization was necessary. Since tissue temperature can be recorded continuously, intermittent quantitative in-vivo calibration seems possibly by evaluation of "heater off" curves in the perfused and non-perfused tissue. As the flowmeter is insensitive to tissue temperature, it can be used for long-term recordings.

  13. Improved Segmented-Flow Tracer-Monitored Titration for Automated Measurement of Total Alkalinity in Seawater

    NASA Astrophysics Data System (ADS)

    Spaulding, R. S.; Hales, B.; Beck, J. C.; Degrandpre, M. D.

    2008-12-01

    The four measurable inorganic carbon parameters commonly measured as part of oceanic carbon cycle studies are total dissolved inorganic carbon (DIC), total alkalinity (AT), hydrogen ion concentration (pH) and partial pressure of CO2 (pCO2). AT determination is critical for anthropogenic CO2 inventory calculations and for quantifying CaCO3 saturation. Additionally, measurement of AT in combination with one other carbonate parameter can be used to describe the inorganic carbon equilibria. Current methods for measuring AT require calibrated volumetric flasks and burettes, gravimetry, or precise flow measurements. These methods also require analysis times of ˜15 min and sample volumes of ˜200 mL, and sample introduction is not automated, resulting in labor-intensive measurements and low temporal resolution. The Tracer Monitored Titration (TMT) system was previously developed at the University of Montana for AT measurements. The TMT is not dependent on accurate gravimetric, volumetric or flow rate measurements because it relies on a pH-sensitive indicator (tracer) to track the amount of titrant added to the sample. Sample and a titrant-indicator mixture are mechanically stirred in an optical flow cell and pH is calculated using the indicator equilibrium constant and the spectrophotometrically determined concentrations of the acid and base forms of the indicator. AT is then determined using these data in a non-linear least squares regression of the AT mass and proton balances. The precision and accuracy of the TMT are 2 and 4 micromol per kg in 16 min using 110-mL of sample. The TMT is dependent on complete mixing of titrant with the sample and accurate absorbance measurements. We have developed the segmented-flow TMT (SF- TMT) to improve on these aspects and decrease sample analysis time. The TMT uses segmented flow instead of active mixing and a white LED instead of a tungsten-halogen light source. Air is added to the liquid flow stream, producing segments of liquid

  14. COUNTERCURRENT FLOW LIMITATION EXPERIMENTS AND MODELING FOR IMPROVED REACTOR SAFETY

    SciTech Connect

    Vierow, Karen

    2008-09-26

    This project is investigating countercurrent flow and “flooding” phenomena in light water reactor systems to improve reactor safety of current and future reactors. To better understand the occurrence of flooding in the surge line geometry of a PWR, two experimental programs were performed. In the first, a test facility with an acrylic test section provided visual data on flooding for air-water systems in large diameter tubes. This test section also allowed for development of techniques to form an annular liquid film along the inner surface of the “surge line” and other techniques which would be difficult to verify in an opaque test section. Based on experiences in the air-water testing and the improved understanding of flooding phenomena, two series of tests were conducted in a large-diameter, stainless steel test section. Air-water test results and steam-water test results were directly compared to note the effect of condensation. Results indicate that, as for smaller diameter tubes, the flooding phenomena is predominantly driven by the hydrodynamics. Tests with the test sections inclined were attempted but the annular film was easily disrupted. A theoretical model for steam venting from inclined tubes is proposed herein and validated against air-water data. Empirical correlations were proposed for air-water and steam-water data. Methods for developing analytical models of the air-water and steam-water systems are discussed, as is the applicability of the current data to the surge line conditions. This report documents the project results from July 1, 2005 through June 30, 2008.

  15. TOPAZ: The transient one-dimensional pipe flow analyzer: An update on code improvements and increased capabilities

    SciTech Connect

    Winters, W.S.

    1987-09-01

    TOPAZ is a ''user-friendly'' computer code for modeling the one-dimensional, transient physics of multi-species gas transfer in arbitrary arrangements of pipes, valves, vessels, and flow branches. This report, the fourth in a series of reports documenting TOPAZ, discusses coding improvements and the addition of new capabilities. These improvements make the current version of TOPAZ considerably more versatile than the original version which was distributed last year. For example, the new version does not restrict the user to modeling only hydrogen and helium isotope flows. Users now have the capability of modeling arbitrary gas mixture flows. In addition users may define time-dependent functions for mass generation, energy deposition, flow area, and maximum integration time step. Parallel flow paths and flows through channels having noncircular cross-sections may now be simulated. Improvements in TOPAZ mesh generation have been made which permit users to add additional ''plumbing'' to existing models without renumbering the mesh. 7 refs., 3 figs., 8 tabs.

  16. Additional research on instabilities in atmospheric flow systems associated with clear air turbulence

    NASA Technical Reports Server (NTRS)

    Stoeffler, R. C.

    1972-01-01

    Analytical and experimental fluid mechanics studies were conducted to investigate instabilities in atmospheric flow systems associated with clear air turbulence. The experimental portion of the program was conducted using an open water channel which allows investigation of flows having wide ranges of shear and density stratification. The program was primarily directed toward studies of the stability of straight, stratified shear flows with particular emphasis on the effects of velocity profile on stability; on studies of three-dimensional effects on the breakdown region in shear layers; on the the interaction of shear flows with long-wave length internal waves; and on the stability of shear flows consisting of adjacent stable layers. The results of these studies were used to evaluate methods used in analyses of CAT encounters in the atmosphere involving wave-induced shear layer instabilities of the Kelvin-Helmholta type. A computer program was developed for predicting shear-layer instability and CAT induced by mountain waves. This technique predicts specific altitudes and locations where CAT would be expected.

  17. Improved macroscopic traffic flow model for aggressive drivers

    SciTech Connect

    Mendez, A. R.; Velasco, R. M.

    2011-03-24

    As has been done for the treatment of diluted gases, kinetic methods are formulated for the study of unidirectional freeway traffic. Fluid dynamic models obtained from kinetic equations have inherent restrictions, the principal one is the restriction to the low density regime. Macroscopic models obtained from kinetic equations tends to selfrestrict to this regime and makes impossible to observe the medium density region. In this work, we present some results heading to improve this model and extend the observable region. Now, we are presenting a fluid dynamic model for aggressive drivers obtained from kinetic assumptions to extend the model to the medium density region in order to study synchronization phenomena which is a very interesting transition phase between free flow and traffic jams. We are changing the constant variance prefactor condition imposed before by a variance prefactor density dependent, the numerical solution of the model is presented, analyzed and contrasted with the previous one. We are also comparing our results with heuristic macroscopic models and real traffic observations.

  18. Enhancement of the anaerobic hydrolysis and fermentation of municipal solid waste in leachbed reactors by varying flow direction during water addition and leachate recycle

    SciTech Connect

    Uke, Matthew N.; Stentiford, Edward

    2013-06-15

    Highlights: ► Combined downflow and upflow water addition improved hydraulic conductivity. ► Upflow water addition unclogged perforated screen leading to more leachate flow. ► The volume of water added and transmitted positively correlated with hydrolysis process. ► Combined downflow and upflow water addition increased COD production and yield. ► Combined downflow and upflow leachate recycle improved leachate and COD production. - Abstract: Poor performance of leachbed reactors (LBRs) is attributed to channelling, compaction from waste loading, unidirectional water addition and leachate flow causing reduced hydraulic conductivity and leachate flow blockage. Performance enhancement was evaluated in three LBRs M, D and U at 22 ± 3 °C using three water addition and leachate recycle strategies; water addition was downflow in D throughout, intermittently upflow and downflow in M and U with 77% volume downflow in M, 54% volume downflow in U while the rest were upflow. Leachate recycle was downflow in D, alternately downflow and upflow in M and upflow in U. The strategy adopted in U led to more water addition (30.3%), leachate production (33%) and chemical oxygen demand (COD) solubilisation (33%; 1609 g against 1210 g) compared to D (control). The total and volatile solids (TS and VS) reductions were similar but the highest COD yield (g-COD/g-TS and g-COD/g-VS removed) was in U (1.6 and 1.9); the values were 1.33 and 1.57 for M, and 1.18 and 1.41 for D respectively. The strategy adopted in U showed superior performance with more COD and leachate production compared to reactors M and D.

  19. Nitrite addition to acidified sludge significantly improves digestibility, toxic metal removal, dewaterability and pathogen reduction

    NASA Astrophysics Data System (ADS)

    Du, Fangzhou; Keller, Jürg; Yuan, Zhiguo; Batstone, Damien J.; Freguia, Stefano; Pikaar, Ilje

    2016-12-01

    Sludge management is a major issue for water utilities globally. Poor digestibility and dewaterability are the main factors determining the cost for sludge management, whereas pathogen and toxic metal concentrations limit beneficial reuse. In this study, the effects of low level nitrite addition to acidified sludge to simultaneously enhance digestibility, toxic metal removal, dewaterability and pathogen reduction were investigated. Waste activated sludge (WAS) from a full-scale waste water treatment plant was treated at pH 2 with 10 mg NO2‑-N/L for 5 h. Biochemical methane potential tests showed an increase in the methane production of 28%, corresponding to an improvement from 247 ± 8 L CH4/kg VS to 317 ± 1 L CH4/kg VS. The enhanced removal of toxic metals further increased the methane production by another 18% to 360 ± 6 L CH4/kg VS (a total increase of 46%). The solids content of dewatered sludge increased from 14.6 ± 1.4% in the control to 18.2 ± 0.8%. A 4-log reduction for both total coliforms and E. coli was achieved. Overall, this study highlights the potential of acidification with low level nitrite addition as an effective and simple method achieving multiple improvements in terms of sludge management.

  20. Nitrite addition to acidified sludge significantly improves digestibility, toxic metal removal, dewaterability and pathogen reduction

    PubMed Central

    Du, Fangzhou; Keller, Jürg; Yuan, Zhiguo; Batstone, Damien J.; Freguia, Stefano; Pikaar, Ilje

    2016-01-01

    Sludge management is a major issue for water utilities globally. Poor digestibility and dewaterability are the main factors determining the cost for sludge management, whereas pathogen and toxic metal concentrations limit beneficial reuse. In this study, the effects of low level nitrite addition to acidified sludge to simultaneously enhance digestibility, toxic metal removal, dewaterability and pathogen reduction were investigated. Waste activated sludge (WAS) from a full-scale waste water treatment plant was treated at pH 2 with 10 mg NO2−-N/L for 5 h. Biochemical methane potential tests showed an increase in the methane production of 28%, corresponding to an improvement from 247 ± 8 L CH4/kg VS to 317 ± 1 L CH4/kg VS. The enhanced removal of toxic metals further increased the methane production by another 18% to 360 ± 6 L CH4/kg VS (a total increase of 46%). The solids content of dewatered sludge increased from 14.6 ± 1.4% in the control to 18.2 ± 0.8%. A 4-log reduction for both total coliforms and E. coli was achieved. Overall, this study highlights the potential of acidification with low level nitrite addition as an effective and simple method achieving multiple improvements in terms of sludge management. PMID:28004811

  1. Towards the design of new and improved drilling fluid additives using molecular dynamics simulations.

    PubMed

    Anderson, Richard L; Greenwel, H Christopher; Suter, James L; Jarvis, Rebecca M; Coveney, Peter V

    2010-03-01

    During exploration for oil and gas, a technical drilling fluid is used to lubricate the drill bit, maintain hydrostatic pressure, transmit sensor readings, remove rock cuttings and inhibit swelling of unstable clay based reactive shale formations. Increasing environmental awareness and resulting legislation has led to the search for new, improved biodegradable drilling fluid components. In the case of additives for clay swelling inhibition, an understanding of how existing effective additives interact with clays must be gained to allow the design of improved molecules. Owing to the disordered nature and nanoscopic dimension of the interlayer pores of clay minerals, computer simulations have become an increasingly useful tool for studying clay-swelling inhibitor interactions. In this work we briefly review the history of the development of technical drilling fluids, the environmental impact of drilling fluids and the use of computer simulations to study the interactions between clay minerals and swelling inhibitors. We report on results from some recent large-scale molecular dynamics simulation studies on low molecular weight water-soluble macromolecular inhibitor molecules. The structure and interactions of poly(propylene oxide)-diamine, poly(ethylene glycol) and poly(ethylene oxide)-diacrylate inhibitor molecules with montmorillonite clay are studied.

  2. Improving Brush Polymer Infrared One-Dimensional Photonic Crystals via Linear Polymer Additives

    SciTech Connect

    Macfarlane, Robert J.; Kim, Bongkeun; Lee, Byeongdu; Weitekamp, Raymond A.; Bates, Christopher M.; Lee, Siu Fung; Chang, Alice B.; Delaney, Kris T.; Fredrickson, Glen H.; Atwater, Harry A.; Grubbs, Robert H.

    2014-12-17

    Brush block copolymers (BBCPs) enable the rapid fabrication of self-assembled one-dimensional photonic crystals with photonic band gaps that are tunable in the UV-vis-IR, where the peak wavelength of reflection scales with the molecular weight of the BBCPs. Due to the difficulty in synthesizing very large BBCPs, the fidelity of the assembled lamellar nanostructures drastically erodes as the domains become large enough to reflect IR light, severely limiting their performance as optical filters. To overcome this challenge, short linear homopolymers are used to swell the arrays to ~180% of the initial domain spacing, allowing for photonic band gaps up to~1410 nm without significant opacity in the visible, demonstrating improved ordering of the arrays. Additionally, blending BBCPs with random copolymers enables functional groups to be incorporated into the BBCP array without attaching them directly to the BBCPs. The addition of short linear polymers to the BBCP arrays thus offers a facile means of improving the self-assembly and optical properties of these materials, as well as adding a route to achieving films with greater functionality and tailorability, without the need to develop or optimize the processing conditions for each new brush polymer synthesized.

  3. Improved Apparatus for the Measurement of Fluctuations of Air Speed in Turbulent Flow

    NASA Technical Reports Server (NTRS)

    Mock, W C , Jr; Dryden, H L

    1934-01-01

    This report describes recent improvements in the design of the equipment associated with the hot-wire anemometer for the measurement of fluctuating air speeds in turbulent air flow, and presents the results of some experimental investigations dealing with the response of the hot wire to speed fluctuations of various frequencies. Attempts at measuring the frequency of the fluctuations encountered in the Bureau of Standards' 54-inch wind tunnel are also reported. In addition, the difficulties encountered in the use of such apparatus and the precautions found helpful in avoiding them are discussed.

  4. Triamine-Modified Polyimides Having Improved Processability and Low Melt Flow Viscosity

    NASA Technical Reports Server (NTRS)

    Meador, Michael A. (Inventor); Nguyen, Baochan N. (Inventor); Eby, Ronald K. (Inventor)

    2001-01-01

    Addition-cured polyimides that contain the reaction product of an aromatic triamine or trianhydride analogue thereof, a reactive end group such as 5-norbornene-2, 3-dicarboxylic acid, ester derivatives of 5-norbornene-2, 3-dicarboxylic acid, anhydride derivatives of 5-norbornene-2, 3-dicarboxylic acid, or 4-phenylethynylphthalic anhydride, an aromatic diamine, and a dialkyl ester of an aromatic tetracarboxylic acid. The resultant starlike polyimides; exhibit lower melt flow viscosity than its linear counterparts, providing for improved processability of the polyimide. Also disclosed are methods for the synthesis of these polyimides as well as composite structures formed using these polyimides.

  5. Effect of Fruit Pomace Addition on Shortbread Cookies to Improve Their Physical and Nutritional Values.

    PubMed

    Tańska, Małgorzata; Roszkowska, Beata; Czaplicki, Sylwester; Borowska, Eulalia Julitta; Bojarska, Justyna; Dąbrowska, Aneta

    2016-09-01

    Fruit pomace remaining after juice extraction is still a source of bioactive compounds. Especially rich in these compounds is the pomace from blackcurrant fruit and from fruits of little-known horticultural plants, like: rowan, rosehip and elderberry. The addition of fruit pomace to bakery and confectionery products, especially to those made of white flour, may significantly enrich their composition with dietary fiber, vitamins and phenolic compounds. This study was aimed at determining the effect of 20 % addition of fruit pomace from rosehip, rowan, blackcurrant and elderberry on the properties of shortbread cookies. The pomace-containing cookies, compared to those without additives, were characterized by a darker color with a higher contribution of yellowness, and by higher hardness. The overall organoleptic assessment was comparable for all types of cookies, however the cookies with pomace were characterized by more perceptible taste and aroma, and were sourer. The extracts from pomace-supplemented cookies had a significantly stronger antioxidant capacity than that from the cookies without pomace, but they were ineffective in inhibiting lipid oxidation. The study showed that fruit pomace could improve the nutritional value of shortbread cookies. Furthermore, non-typical color of such a new product may be attractive to consumers.

  6. Improvement of the cloud point extraction of uranyl ions by the addition of ionic liquids.

    PubMed

    Gao, Song; Sun, Taoxiang; Chen, Qingde; Shen, Xinghai

    2013-12-15

    The cloud point extraction (CPE) of uranyl ions by different kinds of extractants in Triton X-114 (TX-114) micellar solution was investigated upon the addition of ionic liquids (ILs) with various anions, i.e., bromide (Br(-)), tetrafluoroborate (BF4(-)), hexafluorophosphate (PF6(-)) and bis[(trifluoromethyl)sulfonyl]imide (NTf2(-)). A significant increase of the extraction efficiency was found on the addition of NTf2(-) based ILs when using neutral extractant tri-octylphosphine oxide (TOPO), and the extraction efficiency kept high at both nearly neutral and high acidity. However, the CPE with acidic extractants, e.g., bis(2-ethylhexyl) phosphoric acid (HDEHP) and 8-hydroxyquinoline (8-HQ) which are only effective at nearly neutral condition, was not improved by ILs. The results of zeta potential and (19)F NMR measurements indicated that the anion NTf2(-) penetrated into the TX-114 micelles and was enriched in the surfactant-rich phase during the CPE process. Meanwhile, NTf2(-) may act as a counterion in the CPE of UO2(2+) by TOPO. Furthermore, the addition of IL increased the separation factor of UO2(2+) and La(3+), which implied that in the micelle TOPO, NTf2(-) and NO3(-) established a soft template for UO2(2+). Therefore, the combination of CPE and IL provided a supramolecular recognition to concentrate UO2(2+) efficiently and selectively.

  7. Improvement of capacitive performances of symmetric carbon/carbon supercapacitors by addition of nanostructured polypyrrole powder

    NASA Astrophysics Data System (ADS)

    Benhaddad, L.; Gamby, J.; Makhloufi, L.; Pailleret, A.; Pillier, F.; Takenouti, H.

    2016-03-01

    A nanostructured polypyrrole powder was synthesized in a previous work from the oxidation of pyrrole by a nanostructured MnO2 powder used simultaneously as an oxidizing agent and a sacrificial template in a redox heterogeneous mechanism. In this study, this original PPy powder was used as an active additive material with different ratio in carbon/carbon symmetrical supercapacitors whose performances were studied by cyclic voltammetry and electrochemical impedance spectroscopy (EIS) using a Swagelok-type cell. From the EIS spectra, the complex capacitance was extracted using a model involving two Cole-Cole type complex capacitances linked in series. The specific capacitance values evaluated by EIS and cyclic voltammetry are in a good agreement between them. The results show that the addition of nanostructured polypyrrole powder improves significantly the specific capacitance of the carbon electrode and consequently the performances of carbon/carbon supercapacitors. The original and versatile synthesis method used to produce this polypyrrole powder appears to be attractive for large scale production of promising additives for electrode materials of supercapacitors.

  8. Effects of sand addition on turbulent flow over an immobile gravel bed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The factors controlling the complex interaction of a coarse stream bed with flow and sediment are difficult to measure. However, planning for reservoir flushing or dam removal requires knowledge of these interactions. In both cases, impounded sediments are introduced to channel beds that have had ...

  9. New supported beta-amino alcohols as efficient catalysts for the enantioselective addition of diethylzinc to benzaldehyde under flow conditions.

    PubMed

    Burguete, M Isabel; García-Verdugo, Eduardo; Vicent, María J; Luis, Santiago V; Pennemann, Helmut; Graf von, Keyserling Nikolai; Martens, Jürgen

    2002-10-31

    [formula: see text] Polymeric monoliths 10 containing an amino alcohol moiety derived from an industrial waste material represent one of the best ligands for the enantioselective catalytic addition of ZnEt2 to benzaldehyde (99% ee), being recoverable and usable under flow conditions.

  10. The oxidation of organic additives in the positive vanadium electrolyte and its effect on the performance of vanadium redox flow battery

    NASA Astrophysics Data System (ADS)

    Nguyen, Tam D.; Whitehead, Adam; Scherer, Günther G.; Wai, Nyunt; Oo, Moe O.; Bhattarai, Arjun; Chandra, Ghimire P.; Xu, Zhichuan J.

    2016-12-01

    Despite many desirable properties, the vanadium redox flow battery is limited, in the maximum operation temperature that can be continuously endured, before precipitation begins in the positive electrolyte. Many additives have been proposed to improve the thermal stability of the charged positive electrolyte. However, we have found that the apparent stability, revealed in laboratory testing, is often simply an artifact of the test method and arises from the oxidation of the additive, with corresponding partial reduction of V(V) to V(IV). This does not improve the stability of the electrolyte in an operating system. Here, we examined the oxidation of some typical organic additives with carboxyl, alcohol, and multi-functional groups, in sulfuric acid solutions containing V(V). The UV-vis measurements and titration results showed that many compounds reduced the state-of-charge (SOC) of vanadium electrolyte, for example, by 27.8, 88.5, and 81.9% with the addition of 1%wt of EDTA disodium salt, pyrogallol, and ascorbic acid, respectively. The cell cycling also indicated the effect of organic additives on the cell performance, with significant reduction in the usable charge capacity. In addition, a standard screening method for thermally stable additives was introduced, to quickly screen suitable additives for the positive vanadium electrolyte.

  11. Addition of alarm pheromone components improves the effectiveness of desiccant dusts against Cimex lectularius.

    PubMed

    Benoit, Joshua B; Phillips, Seth A; Croxall, Travis J; Christensen, Brady S; Yoder, Jay A; Denlinger, David L

    2009-05-01

    We demonstrate that the addition of bed bug, Cimex lectularius, alarm pheromone to desiccant formulations greatly enhances their effectiveness during short-term exposure. Two desiccant formulations, diatomaceous earth (DE) and Dri-die (silica gel), were applied at the label rate with and without bed bug alarm pheromone components, (E)-2-hexenal, (E)-2-octenal, and a (E)-2-hexenal:(E)-2-octenal blend. First-instar nymphs and adult females were subjected to 10-min exposures, and water loss rates were used to evaluate the response. Optimal effectiveness was achieved with a pheromone concentration of 0.01 M. With Dri-die alone, the water loss was 21% higher than in untreated controls, and water loss increased nearly two times with (E)-2-hexenal and (E)-2-octenal and three times with the (E)-2-hexenal: (E)-2-octenal blend. This shortened survival of first-instar nymphs from 4 to 1 d, with a similar reduction noted in adult females. DE was effective only if supplemented with pheromone, resulting in a 50% increase in water loss over controls with the (E)-2-hexenal:(E)-2-octenal blend, and a survival decrease from 4 to 2 d in first-instar nymphs. Consistently, the addition of the pheromone blend to desiccant dust was more effective than adding either component by itself or by using Dri-die or DE alone. Based on observations in a small microhabitat, the addition of alarm pheromone components prompted bed bugs to leave their protective harborages and to move through the desiccant, improving the use of desiccants for control. We concluded that short exposure to Dri-die is a more effective treatment against bed bugs than DE and that the effectiveness of the desiccants can be further enhanced by incorporation of alarm pheromone. Presumably, the addition of alarm pheromone elevates excited crawling activity, thereby promoting cuticular changes that increase water loss.

  12. DOD Financial Management: Additional Efforts Needed to Improve Audit Readiness of Navy Military Pay and Other Related Activities

    DTIC Science & Technology

    2015-09-01

    DOD FINANCIAL MANAGEMENT Additional Efforts Needed to Improve Audit Readiness of Navy Military Pay and Other Related...REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE DOD Financial Management: Additional Efforts Needed to Improve Audit ...Additional Efforts Needed to Improve Audit Readiness of Navy Military Pay and Other Related Activities Why GAO Did This Study DOD continues to work

  13. Does Glucagon Improve Survival in a Porcine (Sus Scrofa) of Adult Asphyxial Cardiac Arrest in Addition to Standard Epinephrine Therapy?

    DTIC Science & Technology

    2012-01-17

    UDIIILI: oa. I..UN I ItA!.. I NUMDI:It Does Glucagon improve survival in a porcine (Sus Scrofa ) of adult asphyxial cardiac arrest in addition to...EXPIRATION DATE: 25 Mar 13 PROTOCOL TITLE: Does Glucagon Improve Survival in a Porcine (Sus scrofa ) Model of Adult Asphyxial Cardiac Arrest in Addition...Additions: Deletions: 2 Protocol No: A-2007-03 Protocol Title: Does Glucagon Improve Survival in a Porcine (Sus scrofa ) Model of Adult Asphyxial

  14. Using patient flow simulation to improve access at a multidisciplinary sleep centre.

    PubMed

    Pendharkar, Sachin R; Bischak, Diane P; Rogers, Paul; Flemons, Ward; Noseworthy, Tom W

    2015-06-01

    The lack of timely access to diagnosis and treatment for sleep disorders is well described, but little attention has been paid to understanding how multiple system constraints contribute to long waiting times. The objectives of this study were to identify system constraints leading to long waiting times at a multidisciplinary sleep centre, and to use patient flow simulation modelling to test solutions that could improve access. Discrete-event simulation models of patient flow were constructed using historical data from 150 patients referred to the sleep centre, and used to both examine reasons for access delays and to test alternative system configurations that were predicted by administrators to reduce waiting times. Four possible solutions were modelled and compared with baseline, including addition of capacity to different areas at the sleep centre and elimination of prioritization by urgency. Within the model, adding physician capacity improved time from patient referral to initial physician appointment, but worsened time from polysomnography requisition to test completion, and had no effect on time from patient referral to treatment initiation. Adding respiratory therapist did not improve model performance compared with baseline. Eliminating triage prioritization worsened time to physician assessment and treatment initiation for urgent patients without improving waiting times overall. This study demonstrates that discrete-event simulation can identify multiple constraints in access-limited healthcare systems and allow suggested solutions to be tested before implementation. The model of this sleep centre predicted that investments in capacity expansion proposed by administrators would not reduce the time to a clinically meaningful patient outcome.

  15. Improving patient flow in pre-operative assessment

    PubMed Central

    Stark, Cameron; Gent, Anne; Kirkland, Linda

    2015-01-01

    Annual patient attendances at a pre-operative assessment department increased by 24.8% from 5659 in 2009, to 7062 in 2012. The unit was staffed by administrative staff, nurses, and health care assistants (HCA). Medical review was accessed via on call medical staff, or notes were sent to anaesthetists for further review. With rising demand, patient waits increased. The average lead time for a patient (time from entering the department to leaving) was 79 minutes. 9.3% of patients attended within two weeks of their scheduled surgery date. 10% of patients were asked to return on a later day, as there was not sufficient capacity to undertake their assessment. There were nine routes of referral in to the department. Patients moved between different clinic rooms and the waiting area several times. Work patterns were uneven, as many attendances were from out-patient clinics which meant peak attendance times were linked to clinic times. There were substantial differences in the approaches of different nurses, making the HCA role difficult. Patients reported dissatisfaction with waits. Using a Lean quality improvement process with rapid PDSA cycles, the service changed to one in which patients were placed in a room, and remained there for the duration of their assessment. Standard work was developed for HCWs and nurses. Rooms were standardised using 5S processes, and set up improved to reduce time spent looking for supplies. A co-ordinator role was introduced using existing staff to monitor flow and to organise the required medical assessments and ECGs. Timing of booked appointments were altered to take account of clinic times. Routes in to the department were reduced from nine to one. Ten months after the work began, the average lead time had reduced to 59 minutes. The proportion of people attending within two weeks of their surgery decreased from 9.3% to 5.3%. Referrals for an anaesthetic opinion decreased from 30% to 20%, and in the month reviewed no one had to return to

  16. Improving the quality of fresh-cut apples, pears, and melons using natural additives.

    PubMed

    Alandes, L; Quiles, A; Pérez-Munuera, I; Hernando, I

    2009-03-01

    Improving the quality of different fresh-cut fruits by adding natural substances was studied. "Fuji" apples, "Flor de Invierno" pears, and "Piel de Sapo" melons were treated with calcium lactate, N-acetyl-L-cysteine, glutathione, and malic acid and stored for 4 wk at 4 degrees C. Instrumental texture (penetration), microstructure (light microscopy), acidity, soluble solids, color, pectinmethylesterase activity, and microflora were studied. The results showed that the combined treatment reinforced the cell walls strengthening the structure and texture of these fruits and maintained the L* and a* values throughout 4 wk of storage at 4 degrees C. The combination of additives provided low microbial counts in apples until the 4th week and in melons until the 2nd week. So, this combined treatment could be used to extend the shelf life of some fresh-cut fruits while preserving their quality.

  17. Additional Arctic observations improve weather and sea-ice forecasts for the Northern Sea Route.

    PubMed

    Inoue, Jun; Yamazaki, Akira; Ono, Jun; Dethloff, Klaus; Maturilli, Marion; Neuber, Roland; Edwards, Patti; Yamaguchi, Hajime

    2015-11-20

    During ice-free periods, the Northern Sea Route (NSR) could be an attractive shipping route. The decline in Arctic sea-ice extent, however, could be associated with an increase in the frequency of the causes of severe weather phenomena, and high wind-driven waves and the advection of sea ice could make ship navigation along the NSR difficult. Accurate forecasts of weather and sea ice are desirable for safe navigation, but large uncertainties exist in current forecasts, partly owing to the sparse observational network over the Arctic Ocean. Here, we show that the incorporation of additional Arctic observations improves the initial analysis and enhances the skill of weather and sea-ice forecasts, the application of which has socioeconomic benefits. Comparison of 63-member ensemble atmospheric forecasts, using different initial data sets, revealed that additional Arctic radiosonde observations were useful for predicting a persistent strong wind event. The sea-ice forecast, initialised by the wind fields that included the effects of the observations, skilfully predicted rapid wind-driven sea-ice advection along the NSR.

  18. Additives for vaccine storage to improve thermal stability of adenoviruses from hours to months

    NASA Astrophysics Data System (ADS)

    Pelliccia, Maria; Andreozzi, Patrizia; Paulose, Jayson; D'Alicarnasso, Marco; Cagno, Valeria; Donalisio, Manuela; Civra, Andrea; Broeckel, Rebecca M.; Haese, Nicole; Jacob Silva, Paulo; Carney, Randy P.; Marjomäki, Varpu; Streblow, Daniel N.; Lembo, David; Stellacci, Francesco; Vitelli, Vincenzo; Krol, Silke

    2016-11-01

    Up to 80% of the cost of vaccination programmes is due to the cold chain problem (that is, keeping vaccines cold). Inexpensive, biocompatible additives to slow down the degradation of virus particles would address the problem. Here we propose and characterize additives that, already at very low concentrations, improve the storage time of adenovirus type 5. Anionic gold nanoparticles (10-8-10-6 M) or polyethylene glycol (PEG, molecular weight ~8,000 Da, 10-7-10-4 M) increase the half-life of a green fluorescent protein expressing adenovirus from ~48 h to 21 days at 37 °C (from 7 to >30 days at room temperature). They replicate the known stabilizing effect of sucrose, but at several orders of magnitude lower concentrations. PEG and sucrose maintained immunogenicity in vivo for viruses stored for 10 days at 37 °C. To achieve rational design of viral-vaccine stabilizers, our approach is aided by simplified quantitative models based on a single rate-limiting step.

  19. Additional Arctic observations improve weather and sea-ice forecasts for the Northern Sea Route

    PubMed Central

    Inoue, Jun; Yamazaki, Akira; Ono, Jun; Dethloff, Klaus; Maturilli, Marion; Neuber, Roland; Edwards, Patti; Yamaguchi, Hajime

    2015-01-01

    During ice-free periods, the Northern Sea Route (NSR) could be an attractive shipping route. The decline in Arctic sea-ice extent, however, could be associated with an increase in the frequency of the causes of severe weather phenomena, and high wind-driven waves and the advection of sea ice could make ship navigation along the NSR difficult. Accurate forecasts of weather and sea ice are desirable for safe navigation, but large uncertainties exist in current forecasts, partly owing to the sparse observational network over the Arctic Ocean. Here, we show that the incorporation of additional Arctic observations improves the initial analysis and enhances the skill of weather and sea-ice forecasts, the application of which has socioeconomic benefits. Comparison of 63-member ensemble atmospheric forecasts, using different initial data sets, revealed that additional Arctic radiosonde observations were useful for predicting a persistent strong wind event. The sea-ice forecast, initialised by the wind fields that included the effects of the observations, skilfully predicted rapid wind-driven sea-ice advection along the NSR. PMID:26585690

  20. The replacement of alkyl-phenol ethoxylates to improve the environment acceptability of drilling fluid additives

    SciTech Connect

    Getliff, J.M.; James, S.G.

    1996-12-31

    Alkyl-phenol ethoxylates (APEO) are a class of surfactants which have been used widely in the drilling fluid industry. The popularity of these surfactants is based on their cost effectiveness, availability and the range of hydrophilic-lipophilic balance values obtainable. Studies have shown that APEOs exhibit oestrogenic effects, and can cause sterility in some male aquatic species. This may have subsequent human consequences and such problems have lead to a banning of their use in some countries and agreements to phase out their use e.g. PARCOM recommendation 92/8. The use of APEOs as additives in detergents, lubricants and stuck-pipe release agents for drilling fluid applications is discussed. The effectiveness of products formulated with APEOs are directly compared with alternative products which are non-persistent and less damaging to aquatic species. Lubricity measurements using standard and in-house designed equipment and washing tests to compare the efficiency of surfactants are explained and product performance results presented. The results show that alternatives to products containing APEOs are available and that in some cases they show a better technical performance. In addition to the improved environmental acceptability of the base chemicals, the better performance enables lower concentrations to be used, hence reducing the environmental impact even further.

  1. Additives for vaccine storage to improve thermal stability of adenoviruses from hours to months

    PubMed Central

    Pelliccia, Maria; Andreozzi, Patrizia; Paulose, Jayson; D'Alicarnasso, Marco; Cagno, Valeria; Donalisio, Manuela; Civra, Andrea; Broeckel, Rebecca M.; Haese, Nicole; Jacob Silva, Paulo; Carney, Randy P.; Marjomäki, Varpu; Streblow, Daniel N.; Lembo, David; Stellacci, Francesco; Vitelli, Vincenzo; Krol, Silke

    2016-01-01

    Up to 80% of the cost of vaccination programmes is due to the cold chain problem (that is, keeping vaccines cold). Inexpensive, biocompatible additives to slow down the degradation of virus particles would address the problem. Here we propose and characterize additives that, already at very low concentrations, improve the storage time of adenovirus type 5. Anionic gold nanoparticles (10−8–10−6 M) or polyethylene glycol (PEG, molecular weight ∼8,000 Da, 10−7–10−4 M) increase the half-life of a green fluorescent protein expressing adenovirus from ∼48 h to 21 days at 37 °C (from 7 to >30 days at room temperature). They replicate the known stabilizing effect of sucrose, but at several orders of magnitude lower concentrations. PEG and sucrose maintained immunogenicity in vivo for viruses stored for 10 days at 37 °C. To achieve rational design of viral-vaccine stabilizers, our approach is aided by simplified quantitative models based on a single rate-limiting step. PMID:27901019

  2. Improvement of attenuation functions of a clayey sandstone for landfill leachate containment by bentonite addition.

    PubMed

    Ruiz, Ana I; Fernández, Raúl; Sánchez Jiménez, Nicanor; Rodríguez Rastrero, Manuel; Regadío, Mercedes; de Soto, Isabel S; Cuevas, Jaime

    2012-03-01

    Enhanced sand-clay mixtures have been prepared by using a sandstone arkosic material and have been evaluated for consideration as landfill liners. A lab-scale test was carried out under controlled conditions with different amended natural sandstones whereby leachate was passed through the compacted mixtures. The compacted samples consisted of siliceous sand (quartz-feldspar sand separated from the arkose sandstone) and clay (purified clay from arkose sandstone and two commercial bentonites) materials that were mixed in different proportions. The separation of mineral materials from a common and abundant natural source, for soil protection purposes, is proposed as an economic and environmentally efficient practice. The liner qualities were compared for their mineralogical, physicochemical and major ions transport and adsorption properties. Although all samples fulfilled hydraulic conductivity requirements, the addition of bentonite to arkose sandstone was determined to be an effective strategy to decrease the permeability of the soil and to improve the pollutants retention. The clay materials from arkose sandstone also contributed to pollutant retention by a significant improvement of the cation exchange capacity of the bulk material. However, the mixtures prepared with clay materials from the arkose, exhibited a slight increase of hydraulic conductivity. This effect has to be further evaluated.

  3. Significantly improved cyclability of lithium manganese oxide under elevated temperature by an easily oxidized electrolyte additive

    NASA Astrophysics Data System (ADS)

    Zhu, Yunmin; Rong, Haibo; Mai, Shaowei; Luo, Xueyi; Li, Xiaoping; Li, Weishan

    2015-12-01

    Spinel lithium manganese oxide, LiMn2O4, is a promising cathode for lithium ion battery in large-scale applications, because it possesses many advantages compared with currently used layered lithium cobalt oxide (LiCoO2) and olivine phosphate (LiFePO4), including naturally abundant resource, environmental friendliness and high and long work potential plateau. Its poor cyclability under high temperature, however, limits its application. In this work, we report a significant cyclability improvement of LiMn2O4 under elevated temperature by using dimethyl phenylphonite (DMPP) as an electrolyte additive. Charge/discharge tests demonstrate that the application of 0.5 wt.% DMPP yields a capacity retention improvement from 16% to 82% for LiMn2O4 after 200 cycles under 55 °C at 1 C (1C = 148 mAh g-1) between 3 and 4.5 V. Electrochemical and physical characterizations indicate that DMPP is electrochemically oxidized at the potential lower than that for lithium extraction, forming a protective cathode interphase on LiMn2O4, which suppresses the electrolyte decomposition and prevents LiMn2O4 from crystal destruction.

  4. Attempts to improve nitrogen utilization efficiency of aquaponics through nitrifies addition and filler gradation.

    PubMed

    Zou, Yina; Hu, Zhen; Zhang, Jian; Xie, Huijun; Liang, Shuang; Wang, Jinhe; Yan, Runxin

    2016-04-01

    Aquaponics has attracted worldwide attention in recent years and is considered as an alternative technology for conventional aquaculture. In this study, common carp (Cyprinus carpio) and pakchoi (Brassica chinensis) were cultured in lab-scale aquaponics, and attempts were conducted to enhance its nitrogen utilization efficiency (NUE) through two optimization methods, i.e., nitrifies addition (NA) and filler gradation (FG). Results showed that NA and FG could improve the NUE of aquaponics by 8.8 and 16.0%, respectively, compared with control. The total ammonia (TAN) and nitrite (NO2(-)) concentrations in NA and FG systems were maintained at relatively low level (TAN < 0.5 mg/L, NO2(-) < 0.1 mg/L), which demonstrated that both the NA and FG could provide non-toxic water environment for fish culture. Nitrous oxide conversion ratio of the control, NA, and FG were 0.8, 1.2, and 1.7%, respectively, indicating that media-based aquaponics also contributed to global warming. Although the two proposed attempts in this study caused more N2O emission, they made new breakthrough in improving the NUE of aquaponics.

  5. Potential of aeration flow rate and bio-char addition to reduce greenhouse gas and ammonia emissions during manure composting.

    PubMed

    Chowdhury, Md Albarune; de Neergaard, Andreas; Jensen, Lars Stoumann

    2014-02-01

    Aeration is an important factor influencing CO2, CH4, N2O and NH3 emissions from the composting process. Both CH4 and N2O are potent greenhouse gases (GHG) of high importance. Here, we examined the effects of high and low aeration rates together with addition of barley straw with and without bio-char on GHG and NH3 emissions from composting cattle slurry and hen manure in small-scale laboratory composters. Depending on treatment, cumulative C losses via CO2 and CH4 emissions accounted for 11.4-22.5% and 0.004-0.2% of initial total carbon, while N losses as N2O and NH3 emissions comprised 0.05-0.1% and 0.8-26.5% of initial total nitrogen, respectively. Decreasing the flow rate reduced cumulative NH3 losses non-significantly (by 88%) but significantly increased CH4 losses (by 51%) from composting of cattle slurry with barley straw. Among the hen manure treatments evaluated, bio-char addition to composting hen manure and barley straw at low flow rates proved most effective in reducing cumulative NH3 and CH4 losses. Addition of bio-char in combination with barley straw to hen manure at both high and low flow rates reduced total GHG emissions (as CO2-equivalents) by 27-32% compared with barley straw addition alone. Comparisons of flow rates showed that low flow could be an alternative strategy for reducing NH3 losses without any significant change in N2O emissions, pointing to the need for well-controlled composting conditions if gaseous emissions are to be minimised.

  6. Gas flow means for improving efficiency of exhaust hoods

    DOEpatents

    Gadgil, Ashok J.

    1994-01-01

    Apparatus for inhibiting the flow of contaminants in an exhaust enclosure toward an individual located adjacent an opening into the exhaust enclosure by providing a gas flow toward a source of contaminants from a position in front of an individual to urge said contaminants away from the individual toward a gas exit port. The apparatus comprises a gas mani-fold which may be worn by a person as a vest. The manifold has a series of gas outlets on a front face thereof facing away from the individual and toward the contaminants to thereby provide a flow of gas from the front of the individual toward the contaminants.

  7. Gas flow means for improving efficiency of exhaust hoods

    DOEpatents

    Gadgil, A.J.

    1994-01-11

    Apparatus is described for inhibiting the flow of contaminants in an exhaust enclosure toward an individual located adjacent an opening into the exhaust enclosure by providing a gas flow toward a source of contaminants from a position in front of an individual to urge said contaminants away from the individual toward a gas exit port. The apparatus comprises a gas manifold which may be worn by a person as a vest. The manifold has a series of gas outlets on a front face thereof facing away from the individual and toward the contaminants to thereby provide a flow of gas from the front of the individual toward the contaminants. 15 figures.

  8. Use of Additives to Improve Performance of Methyl Butyrate-Based Lithium-Ion Electrolytes

    NASA Technical Reports Server (NTRS)

    Smart, Marshall C.; Bugga, Ratnakumar V.

    2011-01-01

    This work addresses the need for robust rechargeable batteries that can operate well over a wide temperature range. To this end, a number of electrolyte formulations have been developed that incorporate the use of electrolyte additives to improve the high-temperature resilience, low-temperature power capability, and life characteristics of methyl butyrate-based electrolyte solutions. These electrolyte additives include mono-fluoroethylene carbonate (FEC), lithium oxalate, vinylene carbonate (VC), and lithium bis(oxalato)borate (LiBOB), which have been shown to result in improved high-temperature resilience of all carbonate-based electrolytes. Improved performance has been demonstrated of Li-ion cells with methyl butyrate-based electrolytes, including 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %); 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 2% FEC; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 4% FEC; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + lithium oxalate; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 2% VC; and 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 0.10M LiBOB. These electrolytes have been shown to improve performance in MCMB-LiNiCoO2 and graphite-LiNi1/3Co1/3Mn1/3O2 experimental Li-ion cells. A number of LiPF6-based mixed carbonate electrolyte formulations have been developed that contain ester co-solvents, which have been optimized for operation at low temperature, while still providing reasonable performance at high temperature. For example, a number of ester co-solvents were investigated, including methyl propionate (MP), ethyl propionate (EP), methyl butyrate (MB), ethyl butyrate (EB), propyl butyrate (PB), and butyl butyrate (BB) in multi-component electrolytes of the following composition: 1.0M LiPF6 in ethylene carbonate (EC) + ethyl methyl carbonate (EMC) + X (20:60:20 v/v %) [where X = ester co-solvent]. ["Optimized Car bon ate and Ester-Based Li-Ion Electrolytes", NASA Tech Briefs, Vol. 32, No. 4 (April 2008), p. 56.] Focusing upon improved rate

  9. Improved technique for blood flow velocity measurement using Doppler effect

    NASA Astrophysics Data System (ADS)

    Valadares Oliveira, Eduardo J.; Nantes Button, Vera L. d. S.; Maia, Joaquim M.; Costa, Eduardo T.

    2002-04-01

    The Doppler velocimeter developed allows to determine the angle between the ultrasonic beam and the velocity vector of the flow, and to calculate the precise blood flow in a vessel. Four piezoelectric transducers constitute the Doppler velocimeter. Three of these transducers are positioned to form an equilateral triangle (base of a pyramid). When these transducers move simultaneously, backward or forward from the initial position, the emitted ultrasonic beams focalize on a position (peak of the pyramid) closer or farther from the transducers faces, according to the depth of the vessel where we intend to measure de flow. The angle between the transducers allows adjusting the height of this pyramid and the position of the focus (where the three beams meet). A forth transducer is used to determine the diameter of the vessel and monitor the position of the Doppler velocimeter relative to the vessel. Simulation results showed that with this technique is possible to accomplish precise measurement of blood flow.

  10. The Addition of Duration Does Not Improve The Luminosity Relations for Gamma Ray Bursts

    NASA Astrophysics Data System (ADS)

    Collazzi, Andrew C.; Schaefer, Bradley E.

    2009-05-01

    Firmani et al. (2006) proposed a new Gamma Ray Burst (GRB) luminosity relation that showed a significant improvement over the Liso-Epeak relation. (Liso is the isotropic peak luminosity and Epeak is the photon energy of the spectral peak for the burst.) The new proposed relation simply modifies the Epeak value by multiplying it by a power of T0.45, where T0.45 is a particular measure of the GRB duration. We begin by reproducing the results of Firmani for his 19 bursts. We then test the Firmani relation for the same 19 bursts except that we use independently measured values for Liso, T0.45 and Epeak, and we find that the relation deteriorates substantially. We further test the relation by using 60 GRBs with measured spectroscopic redshifts, and find a relation that has a comparable scatter as the original Liso-Epeak relation. That is, a much larger sample of bursts does not reproduce the small scatter as reported by Firmani et al. Finally, we investigate whether the Firmani relation is improved by the use of any of 32 measures of duration (e.g., T90, T50, T90/Npeak, the fluence divided by the peak flux, T0.30, and T0.60) in place of T0.45. The quality of each alternative duration measure is evaluated with the root mean square of the scatter between the observed and fitted logarithmic Liso values. Although we find some durations yield slightly better results than T0.45, the differences between the duration measures are minimal. We find that the addition of a duration does not add any significant improvement to the Liso-Epeak relation. We also present a simple and direct derivation of the Firmani relation from both the Liso-Epeak and Amati (2002) relations. In all we conclude that the Firmani relation neither has an independent existence nor does it provide any significant improvement on previously known relations that are simpler.

  11. Enhanced Cholinergic Activity Improves Cerebral Blood Flow during Orthostatic Stress

    PubMed Central

    Serrador, Jorge M.; Freeman, Roy

    2017-01-01

    Cerebral blood flow (CBF) and consequently orthostatic tolerance when upright depends on dilation of the cerebral vasculature in the face of reduced perfusion pressure associated with the hydrostatic gradient. However, it is still unclear if cholinergic activation plays a role in this dilation. To determine if enhancing central cholinergic activity with the centrally acting acetylcholinesterase inhibitor, physostigmine would increase CBF when upright compared to the peripherally acting acetylcholinesterase inhibitor, neostigmine, or saline. We performed a randomized double-blind dose-ranging study that took place over 3 days in a hospital-based research lab. Eight healthy controls (six women and two men, mean age, 26 years; range 21–33) were given infusions of physostigmine, neostigmine, or saline on three different days. Five-minute tilts were repeated at baseline (no infusion), Dose 1 (0.2 μg/kg/min physostigmine; 0.1 μg/kg/min neostigmine) and Dose 2 (0.6 μg/kg/min physostigmine or 0.3 μg/kg/min neostigmine), and placebo (0.9% NaCl). Cerebral blood velocity, beat-to-beat blood pressure, and end-tidal CO2 were continuously measured during tilts. Physostigmine (0.6 μg/kg/min) resulted in higher cerebral blood velocity during tilt (90.5 ± 1.5%) than the equivalent neostigmine (85.5 ± 2.6%) or saline (84.8 ± 1.7%) trials (P < 0.05). This increase occurred despite a greater postural hypocapnia, suggesting physostigmine had a direct vasodilatory effect on the cerebral vasculature. Cerebral hypoperfusion induced by repeated tilts was eliminated by infusion of physostigmine not neostigmine. In conclusion, this study provides the first evidence that enhancement of central, not peripheral, cholinergic activity attenuates the physiological decrease in CBF seen during upright tilt. These data support the need for further research to determine if enhancing central cholinergic activity may improve symptoms in patients with symptomatic

  12. Copper, Boron, and Cerium Additions in Type 347 Austenitic Steel to Improve Creep Rupture Strength

    NASA Astrophysics Data System (ADS)

    Laha, Kinkar; Kyono, J.; Shinya, Norio

    2012-04-01

    Type 347 austenitic stainless steel (18Cr-12Ni-Nb) was alloyed with copper (3 wt pct), boron (0.01 to 0.06 wt pct), and cerium (0.01 wt pct) with an aim to increase the creep rupture strength of the steel through the improved deformation and cavitation resistance. Short-term creep rupture strength was found to increase with the addition of copper in the 347 steel, but the long-term strength was inferior. Extensive creep cavitation deprived the steel of the beneficial effect of creep deformation resistance induced by nano-size copper particles. Boron and cerium additions in the copper-containing steel increased its creep rupture strength and ductility, which were more for higher boron content. Creep deformation, grain boundary sliding, and creep cavity nucleation and growth in the steel were found to be suppressed by microalloying the copper-containing steel with boron and cerium, and the suppression was more for higher boron content. An auger electron spectroscopic study revealed the segregation of boron instead of sulfur on the cavity surface of the boron- and cerium-microalloyed steel. Cerium acted as a scavenger for soluble sulfur in the steels through the precipitation of cerium sulfide (CeS). This inhibited the segregation of sulfur and facilitated the segregation of boron on cavity surface. Boron segregation on the nucleated cavity surface reduced its growth rate. Microalloying the copper-containing 347 steel with boron and cerium thus enabled to use the full extent of creep deformation resistance rendered by copper nano-size particle by increase in creep rupture strength and ductility.

  13. Improvement of sag resistance by the addition of tungsten in Si-Cr-Mo-V steels

    SciTech Connect

    Nam, W.J.; Lee, C.S.; Ban, D.Y.

    1997-06-01

    The sag resistance of automobile suspension springs is defined, in general, as the resistance to the plastic deformation of springs during repeated loading in service. Since it is one of the most important properties required for high strength spring steels, earlier works on high strength spring steels have concentrated on the improvement of the sag resistance by adding alloying elements or by changing processing treatments. However, the effect of W, a carbide former, on the sag resistance has not been clarified yet. It is, therefore, of interest to investigate the effect of the W addition on the sag resistance. The evaluation of the sag resistance is usually performed by direct static and dynamic tests on prototype springs. However, such a direct method leads to high costs and long testing time. Thus, Furr has proposed the torsional Bauschinger test as one of convenient testing methods, which is related to the Bauschinger effect. He has also shown that the size of hysteresis loops generated in the torsional Bauschinger test has a close relationship with the sag resistance of springs. Ohara, et al. have investigated the correlation between a direct testing on prototype springs and the torsional Bauschinger test, and have shown that a larger loop area in the torsional Bauschinger test represents a higher sag resistance. In view of the foregoing, the purposes of this investigation are to examine the effects of the W addition on (a) the microstructural evolution during tempering and (b) the sag resistance, using the torsional Bauschinger test, for 0.6C-1.5Si-0.5Cr-0.1Mo-0.2V (wt.%) spring steels.

  14. New electrolytes and electrolyte additives to improve the low temperature performance of lithium-ion batteries

    SciTech Connect

    Yang, Xiao-Qing

    2008-08-31

    In this program, two different approaches were undertaken to improve the role of electrolyte at low temperature performance - through the improvement in (i) ionic conductivity and (ii) interfacial behavior. Several different types of electrolytes were prepared to examine the feasibil.ity of using these new electrolytes in rechargeable lithium-ion cells in the temperature range of +40°C to -40°C. The feasibility studies include (a) conductivity measurements of the electrolytes, (b) impedance measurements of lithium-ion cells using the screened electrolytes with di.fferent electrochemical history such as [(i) fresh cells prior to formation cycles, (ii) after first charge, and (iii) after first discharge], (c) electrical performance of the cells at room temperatures, and (d) charge discharge behavior at various low temperatures. Among the different types of electrolytes investigated in Phase I and Phase II of this SBIR project, carbonate-based LiPF6 electrolytes with the proposed additives and the low viscous ester as a third component to the carbonate-based LiPF6 electrolytes show promising results at low temperatures. The latter electrolytes deliver over 80% of room temperature capacity at -20{degrees}C when the lithium-ion cells containing these electrolytes were charged at -20 °C. Also, there was no lithium plating when the lithium­-ion cells using C-C composite anode and LiPF{sub 6} in EC/EMC/MP electrolyte were charged at -20{degrees}C at C/5 rate. The studies of ionic conductivity and AC impedance of these new electrolytes, as well as the charge discharge characteristics of lithium-ion cells using these new electrolytes at various low temperatures provide new findings: The reduced capacity and power capability, as well as the problem of lithium plating at low temperatures charging of lithium-ion cells are primarily due to slow the lithium-ion intercalation/de-intercalation kinetics in the carbon structure.

  15. Cross-flow turbines: physical and numerical model studies towards improved array simulations

    NASA Astrophysics Data System (ADS)

    Wosnik, M.; Bachant, P.

    2015-12-01

    Cross-flow, or vertical-axis turbines, show potential in marine hydrokinetic (MHK) and wind energy applications. As turbine designs mature, the research focus is shifting from individual devices towards improving turbine array layouts for maximizing overall power output, i.e., minimizing wake interference for axial-flow turbines, or taking advantage of constructive wake interaction for cross-flow turbines. Numerical simulations are generally better suited to explore the turbine array design parameter space, as physical model studies of large arrays at large model scale would be expensive. However, since the computing power available today is not sufficient to conduct simulations of the flow in and around large arrays of turbines with fully resolved turbine geometries, the turbines' interaction with the energy resource needs to be parameterized, or modeled. Most models in use today, e.g. actuator disk, are not able to predict the unique wake structure generated by cross-flow turbines. Experiments were carried out using a high-resolution turbine test bed in a large cross-section tow tank, designed to achieve sufficiently high Reynolds numbers for the results to be Reynolds number independent with respect to turbine performance and wake statistics, such that they can be reliably extrapolated to full scale and used for model validation. To improve parameterization in array simulations, an actuator line model (ALM) was developed to provide a computationally feasible method for simulating full turbine arrays inside Navier--Stokes models. The ALM predicts turbine loading with the blade element method combined with sub-models for dynamic stall and flow curvature. The open-source software is written as an extension library for the OpenFOAM CFD package, which allows the ALM body force to be applied to their standard RANS and LES solvers. Turbine forcing is also applied to volume of fluid (VOF) models, e.g., for predicting free surface effects on submerged MHK devices. An

  16. Development of a New Hypersonic Shock Tunnel Facility to Investigate Electromagnetic Energy Addition for Flow Control and Basic Supersonic Combustion

    NASA Astrophysics Data System (ADS)

    Toro, P. G. P.; Minucci, M. A. S.; Chanes, J. B.; Pereira, A. L.; Nagamatsu, H. T.

    2006-05-01

    A new 0.6-m. diameter Hypersonic Shock Tunnel is been designed, fabricated and will be installed at the Laboratory of Aerothermodynamics and Hypersonics IEAv-CTA, Brazil. The brand new hypersonic facility, designated as T3, is primarily intended to be used as an important tool in the investigation of supersonic combustion management and of electromagnetic energy addition for flow control. The design of the runnel enables relatively long test times, 2-10 milliseconds, suitable for basic supersonic combustion and energy addition by laser experiments. Free stream Mach numbers ranging from 6 to 25 can be produced and stagnation pressures and temperatures of 200 atm. and 5,500 K, respectively, can be generated. Shadowgraph and schlieren optical techniques will be used for flow visualization and the new facility is expected to be commissioned by the end of 2006.

  17. Flue gas conditioning for improved particle collection in electrostatic precipitators. First topical report, Results of laboratory screening of additives

    SciTech Connect

    Durham, M.D.

    1993-04-16

    Several tasks have been completed in a program to evaluate additives to improve fine particle collection in electrostatic precipitators. Screening tests and laboratory evaluations of additives are summarized in this report. Over 20 additives were evaluated; four were found to improve flyash precipitation rates. The Insitec particle analyzer was also evaluated; test results show that the analyzer will provide accurate sizing and counting information for particles in the size range of {le} 10 {mu}m dia.

  18. Additions and improvements to the high energy density physics capabilities in the FLASH code

    NASA Astrophysics Data System (ADS)

    Lamb, D. Q.; Flocke, N.; Graziani, C.; Tzeferacos, P.; Weide, K.

    2016-10-01

    FLASH is an open source, finite-volume Eulerian, spatially adaptive radiation magnetohydrodynamics code that has the capabilities to treat a broad range of physical processes. FLASH performs well on a wide range of computer architectures, and has a broad user base. Extensive high energy density physics (HEDP) capabilities have been added to FLASH to make it an open toolset for the academic HEDP community. We summarize these capabilities, emphasizing recent additions and improvements. In particular, we showcase the ability of FLASH to simulate the Faraday Rotation Measure produced by the presence of magnetic fields; and proton radiography, proton self-emission, and Thomson scattering diagnostics with and without the presence of magnetic fields. We also describe several collaborations with the academic HEDP community in which FLASH simulations were used to design and interpret HEDP experiments. This work was supported in part at the University of Chicago by the DOE NNSA ASC through the Argonne Institute for Computing in Science under field work proposal 57789; and the NSF under Grant PHY-0903997.

  19. Additions and Improvements to the FLASH Code for Simulating High Energy Density Physics Experiments

    NASA Astrophysics Data System (ADS)

    Lamb, D. Q.; Daley, C.; Dubey, A.; Fatenejad, M.; Flocke, N.; Graziani, C.; Lee, D.; Tzeferacos, P.; Weide, K.

    2015-11-01

    FLASH is an open source, finite-volume Eulerian, spatially adaptive radiation hydrodynamics and magnetohydrodynamics code that incorporates capabilities for a broad range of physical processes, performs well on a wide range of computer architectures, and has a broad user base. Extensive capabilities have been added to FLASH to make it an open toolset for the academic high energy density physics (HEDP) community. We summarize these capabilities, with particular emphasis on recent additions and improvements. These include advancements in the optical ray tracing laser package, with methods such as bi-cubic 2D and tri-cubic 3D interpolation of electron number density, adaptive stepping and 2nd-, 3rd-, and 4th-order Runge-Kutta integration methods. Moreover, we showcase the simulated magnetic field diagnostic capabilities of the code, including induction coils, Faraday rotation, and proton radiography. We also describe several collaborations with the National Laboratories and the academic community in which FLASH has been used to simulate HEDP experiments. This work was supported in part at the University of Chicago by the DOE NNSA ASC through the Argonne Institute for Computing in Science under field work proposal 57789; and the NSF under grant PHY-0903997.

  20. Improved microstructure of cement-based composites through the addition of rock wool particles

    SciTech Connect

    Lin, Wei-Ting; Cheng, An; Huang, Ran; Zou, Si-Yu

    2013-10-15

    Rock wool is an inorganic fibrous substance produced by steam blasting and cooling molten glass. As with other industrial by-products, rock wool particles can be used as cementitious materials or ultra fine fillers in cement-based composites. This study investigated the microstructure of mortar specimens produced with cement-based composites that include various forms of rock wool particles. It conducted compressive strength testing, rapid chloride penetration tests, X-ray diffraction analysis, thermo-gravimetric analysis, and scanning electronic microscopy to evaluate the macro- and micro-properties of the cement-based composites. Test results indicate that inclusion of rock wool particles in composites improved compressive strength and reduced chloride ion penetration at the age of 91 days due to the reduction of calcium hydroxide content. Microscopic analysis confirms that the use of rock wool particles contributed to the formation of a denser, more compact microstructure within the hardened paste. In addition, X-ray diffraction analysis shows few changes in formation of pozzolanic reaction products and no new hydrations are formed with incorporating rock wool particles. - Highlights: • We report the microstructural characterization of cement-based composites. • Different mixes produced with various rock wool particles have been tested. • The influence of different mixes on macro and micro properties has been discussed. • The macro properties are included compressive strength and permeability. • XRD and SEM observations confirm the pozzolanic reaction in the resulting pastes.

  1. Elements of an improved model of debris‐flow motion

    USGS Publications Warehouse

    Iverson, Richard M.

    2009-01-01

    A new depth‐averaged model of debris‐flow motion describes simultaneous evolution of flow velocity and depth, solid and fluid volume fractions, and pore‐fluid pressure. Non‐hydrostatic pore‐fluid pressure is produced by dilatancy, a state‐dependent property that links the depth‐averaged shear rate and volumetric strain rate of the granular phase. Pore‐pressure changes caused by shearing allow the model to exhibit rate‐dependent flow resistance, despite the fact that the basal shear traction involves only rate‐independent Coulomb friction. An analytical solution of simplified model equations shows that the onset of downslope motion can be accelerated or retarded by pore‐pressure change, contingent on whether dilatancy is positive or negative. A different analytical solution shows that such effects will likely be muted if downslope motion continues long enough, because dilatancy then evolves toward zero, and volume fractions and pore pressure concurrently evolve toward steady states.

  2. Improved Flux Formulations for Unsteady Low Mach Number Flows

    DTIC Science & Technology

    2012-07-01

    modeling multi-species flows (as, for example, the combusted exhaust plume from an aircraft engine). One effective way for expressing a general...physical-Mach number and the ratio of specific heats : 2 1 1p p p M M ρ γ ρ γ γ ′  ′ − = +     (5) where 2 2 2 2 minmin max( , , ),1p...the CRUNCH CFD ® code, developed at CRAFT Tech [12]-[15]. The candidate flux formulations for unsteady low Mach number flows will be tested out

  3. U.S. stream flow measurement and data dissemination improve

    USGS Publications Warehouse

    Hirsch, Robert M.; Costa, John E.

    2004-01-01

    Stream flow information is essential for many important uses across a broad range of scales, including global water balances, engineering design, flood forecasting, reservoir operations, navigation, water supply, recreation, and environmental management. Growing populations and competing priorities for water, including preservation and restoration of aquatic habitat, are spurring demand for more accurate, timely, and accessible water data.To be most useful, stream flow information must be collected in a standardized manner, with a known accuracy, and for a long and continuous time period.

  4. What maintains the waters flowing in our rivers? - Rethinking hydrogeology to improve public policy

    NASA Astrophysics Data System (ADS)

    Vasconcelos, Vitor Vieira

    2016-01-01

    This article discusses how new contributions from hydrogeological science in the 20th and 21st centuries have allowed for a better understanding of the processes that affect the maintenance of river flows. Moreover, the way in which this knowledge has been conveyed beyond academia and has been gradually incorporated into public policy for natural resource management is also discussed. This article explains the development of several approaches used to understand the relationships among the management of aquifers, vegetation and river flows, including water balance, aquifer recharge, the piston effect, seasonal effects, and safe and sustainable yields. Additionally, the current challenges regarding the modeling of hydrological processes that integrate groundwater and surface waters are discussed. Examples of studies applied in Brazil that demonstrate these processes and stimulate thought regarding water management strategies are presented. In light of the case studies, it is possible to propose different strategies, each adapted for specific hydrogeological context to maximize aquifer recharge or base flow maintenance. Based on these strategies, the role of infiltration ponds and other artificial recharge techniques is re-evaluated in the context of the mitigation of environmental impacts on the maintenance of river flows. Proposals for the improvement of public policies regarding the payment of related environmental services to stimulate investment in aquifer recharge and the maintenance of base flow, for which the goal is to attain win-win-win situations for the environment, farmers and water users, while preventing land speculation, are discussed. Lastly, a conceptual model for the dissemination of hydrogeological knowledge in public policies is provided, and its challenges and possibilities are discussed.

  5. Improved Flow Modeling in Transient Reactor Safety Analysis Computer Codes

    SciTech Connect

    Holowach, M.J.; Hochreiter, L.E.; Cheung, F.B.

    2002-07-01

    A method of accounting for fluid-to-fluid shear in between calculational cells over a wide range of flow conditions envisioned in reactor safety studies has been developed such that it may be easily implemented into a computer code such as COBRA-TF for more detailed subchannel analysis. At a given nodal height in the calculational model, equivalent hydraulic diameters are determined for each specific calculational cell using either laminar or turbulent velocity profiles. The velocity profile may be determined from a separate CFD (Computational Fluid Dynamics) analysis, experimental data, or existing semi-empirical relationships. The equivalent hydraulic diameter is then applied to the wall drag force calculation so as to determine the appropriate equivalent fluid-to-fluid shear caused by the wall for each cell based on the input velocity profile. This means of assigning the shear to a specific cell is independent of the actual wetted perimeter and flow area for the calculational cell. The use of this equivalent hydraulic diameter for each cell within a calculational subchannel results in a representative velocity profile which can further increase the accuracy and detail of heat transfer and fluid flow modeling within the subchannel when utilizing a thermal hydraulics systems analysis computer code such as COBRA-TF. Utilizing COBRA-TF with the flow modeling enhancement results in increased accuracy for a coarse-mesh model without the significantly greater computational and time requirements of a full-scale 3D (three-dimensional) transient CFD calculation. (authors)

  6. Planning for ambulatory care: simple methods for improving patient flow.

    PubMed

    Schuh, S E; Tolins, I; Westphal, M C; Miller, M C

    1977-06-01

    A combined patient flow and work sampling study was done at the Ambulatory Pediatric Service of the Medical University of South Carolina. The biggest problem was that almost two thirds of the patient's time was spent waiting to see the doctor. Reasons for delay included too few examining rooms, the single block appointment system, and design of the facility.

  7. Toward the improved simulation of microscale gas flow

    NASA Astrophysics Data System (ADS)

    McNenly, Matthew James

    2007-12-01

    Recent interest in fluidic micro-electro-mechanical systems (MEMS) in gaseous environments has increased the need for accurate simulation techniques to aid in their design process. Many fluidic MEMS operate in a low-speed non-equilibrium gas flow regime that is challenging to simulate both accurately and efficiently. Classic computational fluid dynamics techniques (e.g. Navier-Stokes simulation) are based on the assumption that the fluid behaves as a continuum. This assumption, however, becomes increasingly less accurate as the local flow conditions deviate further from local thermodynamic equilibrium. Alternatively, it is possible to achieve an accurate approximation of non-equilibrium gas flows using particle-based methods (e.g. DSMC), but the resulting simulations are much more computationally expensive than the continuum-based method. In fact, for the very low speeds commonly found in fluidic MEMS, the slow convergence of the DSMC solution can lead to intractably long computation times on all but the largest supercomputers. Two different approaches are pursued in this investigation, in an effort to design a physically accurate and computationally efficient simulation of low-speed, non-equilibrium flows. The first approach constructs new empirical models to correct the error in the Navier-Stokes simulation in the transition regime due to the appreciable deviation from local thermodynamic equilibrium. The empirically corrected Navier-Stokes simulation is not actually predicting strongly non-equilibrium gas flows; however, it is shown to be a useful analysis tool in certain design situations. The second more novel approach develops an original quasi-Monte Carlo (QMC) particle simulation that retains the physical accuracy of the DSMC method while at the same time achieving a faster (near-linear) convergence rate. The design of a QMC method is far more complex in general than a Monte Carlo method for the same problem. Further, no known QMC particle simulation has

  8. Improved simulations of heat transfer in liquid metal flows.

    SciTech Connect

    Tzanos, C.

    2011-04-01

    In liquid-metal flows, the predictions of the Nusselt number (heat transfer) by Reynolds-averaged Navier-Stokes models of turbulence that use the assumption of a constant turbulent Prandtl number can be significantly off. Heat transfer analyses were performed with a number of turbulence models for flows in a triangular rod bundle and in a pipe, and model predictions were compared with experimental data. Emphasis was placed on the low Reynolds (low-Re) number k-{var_epsilon} model that resolves the boundary layer and does not use 'logarithmic wall functions.' The high Reynolds (high-Re) number k-{var_epsilon} model underpredicts the Nusselt number up to 30%, while the low-Re number model overpredicts it up to 34%. For high Peclet number values, the low-Re number model provides better predictions than the high-Re number model. For Peclet numbers higher than 1500, the predictions of the Reynolds stress model (RSM) are in very good agreement with experimental measurements, but for lower Peclet number values its predictions are significantly off. A relationship was developed that expresses the turbulent Prandtl number as a function of the ratio of the turbulent viscosity to the molecular viscosity. With this modified turbulent Prandtl number, for the flow in the rod bundle the predictions of the low-Re number model are well within the spread of the experimental measurements. For pipe flow, the model predictions are not as sensitive to the correction of the turbulent Prandtl number as they are in the case of the flow in a bundle. The modified low-Re number model underpredicts the limited experimental data by 4%.

  9. Can Vitamin D Supplementation in Addition to Asthma Controllers Improve Clinical Outcomes in Patients With Asthma?

    PubMed Central

    Luo, Jian; Liu, Dan; Liu, Chun-Tao

    2015-01-01

    Abstract Effects of vitamin D on acute exacerbation, lung function, and fraction of exhaled nitric oxide (FeNO) in patients with asthma are controversial. We aim to further evaluate the roles of vitamin D supplementation in addition to asthma controllers in asthmatics. From 1946 to July 2015, we searched the PubMed, Embase, Medline, Cochrane Central Register of Controlled Trials, and ISI Web of Science using “Vitamin D,” “Vit D,” or “VitD” and “asthma,” and manually reviewed the references listed in the identified articles. Randomized controlled trials which reported rate of asthma exacerbations and adverse events, forced expiratory volume in 1 s (FEV1, % of predicted value), FeNO, asthma control test (ACT), and serum 25-hydroxyvitamin D levels were eligible. We conducted the heterogeneities test and sensitivity analysis of the enrolled studies, and random-effects or fixed-effects model was applied to calculate risk ratio (RR) and mean difference for dichotomous and continuous data, respectively. Cochrane systematic review software Review Manager (RevMan) was used to test the hypothesis by Mann–Whitney U test, which were displayed in Forest plots. Seven trials with a total of 903 patients with asthma were pooled in our final studies. Except for asthma exacerbations (I2 = 81%, χ2 = 10.28, P = 0.006), we did not find statistical heterogeneity in outcome measures. The pooled RR of asthma exacerbation was 0.66 (95% confidence interval: 0.32–1.37), but without significant difference (z = 1.12, P = 0.26), neither was in FEV1 (z = 0.30, P = 0.77), FeNO (z = 0.28, P = 0.78), or ACT (z = 0.92, P = 0.36), although serum 25-hydroxyvitamin D was significantly increased (z = 6.16, P < 0.001). Vitamin D supplementation in addition to asthma controllers cannot decrease asthma exacerbation and FeNO, nor improve lung function and asthma symptoms, although it can be safely applied to increase serum 25

  10. Enhanced Efficacy of Doxorubicin by microRNA-499-Mediated Improvement of Tumor Blood Flow

    PubMed Central

    Okamoto, Ayaka; Asai, Tomohiro; Ryu, Sho; Ando, Hidenori; Maeda, Noriyuki; Dewa, Takehisa; Oku, Naoto

    2016-01-01

    Genetic therapy using microRNA-499 (miR-499) was combined with chemotherapy for the advanced treatment of cancer. Our previous study showed that miR-499 suppressed tumor growth through the inhibition of vascular endothelial growth factor (VEGF) production and subsequent angiogenesis. In the present study, we focused on blood flow in tumors treated with miR499, since some angiogenic vessels are known to lack blood flow. Tetraethylenepentamine-based polycation liposomes (TEPA-PCL) were prepared and modified with Ala-Pro-Arg-Pro-Gly peptide (APRPG) for targeted delivery of miR-499 (APRPG-miR-499) to angiogenic vessels and tumor cells. The tumor blood flow was significantly improved, so-called normalized, after systemic administration of APRPG-miR-499 to Colon 26 NL-17 carcinoma–bearing mice. In addition, the accumulation of doxorubicin (DOX) in the tumors was increased by pre-treatment with APRPG-miR-499. Moreover, the combination therapy of APRPG-miR-499 and DOX resulted in significant suppression of the tumors. Taken together, our present data indicate that miR-499 delivered with APRPG-modified-TEPA-PCL normalized tumor vessels, resulting in enhancement of intratumoral accumulation of DOX. Our findings suggest that APRPG-miR-499 may be a therapeutic, or a combination therapeutic, candidate for cancer treatment. PMID:26797645

  11. Enhanced Efficacy of Doxorubicin by microRNA-499-Mediated Improvement of Tumor Blood Flow.

    PubMed

    Okamoto, Ayaka; Asai, Tomohiro; Ryu, Sho; Ando, Hidenori; Maeda, Noriyuki; Dewa, Takehisa; Oku, Naoto

    2016-01-19

    Genetic therapy using microRNA-499 (miR-499) was combined with chemotherapy for the advanced treatment of cancer. Our previous study showed that miR-499 suppressed tumor growth through the inhibition of vascular endothelial growth factor (VEGF) production and subsequent angiogenesis. In the present study, we focused on blood flow in tumors treated with miR499, since some angiogenic vessels are known to lack blood flow. Tetraethylenepentamine-based polycation liposomes (TEPA-PCL) were prepared and modified with Ala-Pro-Arg-Pro-Gly peptide (APRPG) for targeted delivery of miR-499 (APRPG-miR-499) to angiogenic vessels and tumor cells. The tumor blood flow was significantly improved, so-called normalized, after systemic administration of APRPG-miR-499 to Colon 26 NL-17 carcinoma-bearing mice. In addition, the accumulation of doxorubicin (DOX) in the tumors was increased by pre-treatment with APRPG-miR-499. Moreover, the combination therapy of APRPG-miR-499 and DOX resulted in significant suppression of the tumors. Taken together, our present data indicate that miR-499 delivered with APRPG-modified-TEPA-PCL normalized tumor vessels, resulting in enhancement of intratumoral accumulation of DOX. Our findings suggest that APRPG-miR-499 may be a therapeutic, or a combination therapeutic, candidate for cancer treatment.

  12. Perilla oil improves blood flow through inhibition of platelet aggregation and thrombus formation

    PubMed Central

    Jang, Ja-Young; Kim, Tae-Su; Cai, Jingmei; Kim, Jihyun; Kim, Youngeun; Shin, Kyungha; Kim, Kwang-Sei; Lee, Sung-Pyo; Kang, Myung-Hwa; Choi, Ehn-Kyoung

    2014-01-01

    The inhibitory effects of perilla oil on the platelet aggregation in vitro and thrombosis in vivo were investigated in comparison with aspirin, a well-known blood flow enhancer. Rabbit platelet-rich plasma was incubated with perilla oil and aggregation inducers collagen or thrombin, and the platelet aggregation rate was analyzed. Perilla oil significantly inhibited both the collagen- and thrombin-induced platelet aggregations, in which the thromboxane B2 formation from collagen-activated platelets were reduced in a concentration-dependent manner. Rats were administered once daily by gavage with perilla oil for 1 week, carotid arterial thrombosis was induced by applying 35% FeCl3-soaked filter paper for 10 min, and the blood flow was monitored with a laser Doppler probe. Perilla oil delayed the FeCl3-induced arterial occlusion in a dose-dependent manner, doubling the occlusion time at 0.5 mL/kg. In addition, a high dose (2 mL/kg) of perilla oil greatly prevented the occlusion, comparable to the effect of aspirin (30 mg/kg). The results indicate that perilla oil inhibit platelet aggregation by blocking thromboxane formation, and thereby delay thrombosis following oxidative arterial wall injury. Therefore, it is proposed that perilla oil could be a good candidate without adverse effects for the improvement of blood flow. PMID:24707301

  13. Improving the analytical performance of hydride generation non-dispersive atomic fluorescence spectrometry. Combined effect of additives and optical filters

    NASA Astrophysics Data System (ADS)

    D'Ulivo, Alessandro; Bramanti, Emilia; Lampugnani, Leonardo; Zamboni, Roberto

    2001-10-01

    The effects of tetrahydroborate and acid concentration and the presence of L-cysteine and thiourea were investigated in the determination of As, Bi and Sn using continuous flow hydride generation atomic fluorescence spectrometry (HG AFS). The aim was to find conditions allowing the control of those effects exerting negative influence on the analytical performance of the HG AFS apparatus. The effects taken into account were: (i) the radiation scattering generated by carryover of solution from the gas-liquid separator to the atomizer; (ii) the introduction of molecular species generated by tetrahydroborate decomposition into the atomizer; and (iii) interference effects arising from other elements in the sample matrix and from different acids. The effects (i) and (ii) could be controlled using mild reaction conditions in the HG stage. The effect of HG conditions on carryover was studied by radiation scattering experiments without hydride atomization. Compromised HG conditions were found by studying the effects of tetrahydroborate (0.1-20 g l -1) and acid (0.01-7 mol l -1) concentration, and the addition of L-cysteine (10 g l -1) and thiourea (0.1 mol l -1) on the HG AFS signals. The effect of optical filters was investigated with the aim of improving the signal-to-noise ratio. Optical filters with peak wavelengths of 190 and 220 nm provided an improvement of detection limits by factors of approximately 4 and 2 for As and Te, respectively. Under optimized conditions the detection limits were 6, 5, 3, 2, 2 and 9 ng l -1 for As, Sb, Bi, Sn, Se and Te, respectively. Good tolerance to various acid compositions and sample matrices was obtained by using L-cysteine or thiourea as masking agents. Determination of arsenic in sediment and copper certified reference materials, and of bismuth in steel, sediment, soil and ore certified reference material is reported.

  14. Novel Flow Cytometry Analyses of Boar Sperm Viability: Can the Addition of Whole Sperm-Rich Fraction Seminal Plasma to Frozen-Thawed Boar Sperm Affect It?

    PubMed Central

    Díaz, Rommy; Boguen, Rodrigo; Martins, Simone Maria Massami Kitamura; Ravagnani, Gisele Mouro; Leal, Diego Feitosa; Oliveira, Melissa de Lima; Muro, Bruno Bracco Donatelli; Parra, Beatriz Martins; Meirelles, Flávio Vieira; Papa, Frederico Ozanan; Dell’Aqua, José Antônio; Alvarenga, Marco Antônio; Moretti, Aníbal de Sant’Anna; Sepúlveda, Néstor

    2016-01-01

    Boar semen cryopreservation remains a challenge due to the extension of cold shock damage. Thus, many alternatives have emerged to improve the quality of frozen-thawed boar sperm. Although the use of seminal plasma arising from boar sperm-rich fraction (SP-SRF) has shown good efficacy; however, the majority of actual sperm evaluation techniques include a single or dual sperm parameter analysis, which overrates the real sperm viability. Within this context, this work was performed to introduce a sperm flow cytometry fourfold stain technique for simultaneous evaluation of plasma and acrosomal membrane integrity and mitochondrial membrane potential. We then used the sperm flow cytometry fourfold stain technique to study the effect of SP-SRF on frozen-thawed boar sperm and further evaluated the effect of this treatment on sperm movement, tyrosine phosphorylation and fertility rate (FR). The sperm fourfold stain technique is accurate (R2 = 0.9356, p > 0.01) for simultaneous evaluation of plasma and acrosomal membrane integrity and mitochondrial membrane potential (IPIAH cells). Centrifugation pre-cryopreservation was not deleterious (p > 0.05) for any analyzed variables. Addition of SP-SRF after cryopreservation was able to improve total and progressive motility (p < 0.05) when boar semen was cryopreserved without SP-SRF; however, it was not able to decrease tyrosine phosphorylation (p > 0.05) or improve IPIAH cells (p > 0.05). FR was not (p > 0.05) statistically increased by the addition of seminal plasma, though females inseminated with frozen-thawed boar semen plus SP-SRF did perform better than those inseminated with sperm lacking seminal plasma. Thus, we conclude that sperm fourfold stain can be used to simultaneously evaluate plasma and acrosomal membrane integrity and mitochondrial membrane potential, and the addition of SP-SRF at thawed boar semen cryopreserved in absence of SP-SRF improve its total and progressive motility. PMID:27529819

  15. Edge-Hydroxylated Boron Nitride Nanosheets as an Effective Additive to Improve the Thermal Response of Hydrogels.

    PubMed

    Xiao, Feng; Naficy, Sina; Casillas, Gilberto; Khan, Majharul H; Katkus, Tomas; Jiang, Lei; Liu, Huakun; Li, Huijun; Huang, Zhenguo

    2015-11-25

    Upon flowing hot steam over hexagonal boron nitride (h-BN) bulk powder, efficient exfoliation and hydroxylation of BN occur simultaneously. Through effective hydrogen bonding with water and N-isopropylacrylamide, edge-hydroxylated BN nanosheets dramatically improve the dimensional change and dye release of this temperature-sensitive hydrogel and thereby enhance its efficacy in bionic, soft robotic, and drug-delivery applications.

  16. Flow improvement caused by agents who ignore traffic rules.

    PubMed

    Baek, Seung Ki; Minnhagen, Petter; Bernhardsson, Sebastian; Choi, Kweon; Kim, Beom Jun

    2009-07-01

    A system of agents moving along a road in both directions is studied numerically within a cellular-automata formulation. An agent steps to the right with probability q or to the left with 1-q when encountering other agents. Our model is restricted to two agent types, traffic-rule abiders (q=1) and traffic-rule ignorers (q=1/2) , and the traffic flow, resulting from the interaction between these two types of agents, which is obtained as a function of density and relative fraction. The risk for jamming at a fixed density, when starting from a disordered situation, is smaller when every agent abides by a traffic rule than when all agents ignore the rule. Nevertheless, the absolute minimum occurs when a small fraction of ignorers are present within a majority of abiders. The characteristic features for the spatial structure of the flow pattern are obtained and discussed.

  17. Improvement of Unbalanced Load Flow Program for Large Power Systems

    NASA Astrophysics Data System (ADS)

    Imai, Shinichi; Suzuki, Haruhiko; Iba, Kenji; Fujiwara, Shuhei

    The idea of unbalanced power flow calculation was proposed many years ago. At that time, however, the needs for such techniques was not an argent issue. But modern power system networks are comprised of long untransposed transmission lines. Therefore, for some kind of analysis, it is now almost impossible to treat a system as though it were a symmetrical network. The aims of most previous studies were oriented to solve voltage/current imbalance in local or small system because local imbalance was a serious concern. This is still an important issue, but more recently our needs have become concentrated on practical bulk power systems, since principal EHV lines are entirely untransposed. Following such a background, we have developed a practical unbalanced load flow program. This program was developed for steady state analysis of large scale of practical networks under many possible unbalanced conditions.

  18. Modeling of time dependent localized flow shear stress and its impact on cellular growth within additive manufactured titanium implants

    PubMed Central

    Zhang, Ziyu; Yuan, Lang; Lee, Peter D; Jones, Eric; Jones, Julian R

    2014-01-01

    Bone augmentation implants are porous to allow cellular growth, bone formation and fixation. However, the design of the pores is currently based on simple empirical rules, such as minimum pore and interconnects sizes. We present a three-dimensional (3D) transient model of cellular growth based on the Navier–Stokes equations that simulates the body fluid flow and stimulation of bone precursor cellular growth, attachment, and proliferation as a function of local flow shear stress. The model's effectiveness is demonstrated for two additive manufactured (AM) titanium scaffold architectures. The results demonstrate that there is a complex interaction of flow rate and strut architecture, resulting in partially randomized structures having a preferential impact on stimulating cell migration in 3D porous structures for higher flow rates. This novel result demonstrates the potential new insights that can be gained via the modeling tool developed, and how the model can be used to perform what-if simulations to design AM structures to specific functional requirements. PMID:24664988

  19. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. R.; St. Clair, T. L.; Burks, H. D.; Stoakley, D. M.

    1987-01-01

    A method has been found for enhancing the melt flow of thermoplastic polyimides during processing. A high molecular weight 422 copoly(amic acid) or copolyimide was fused with approximately 0.05 to 5 pct by weight of a low molecular weight amic acid or imide additive, and this melt was studied by capillary rheometry. Excellent flow and improved composite properties on graphite resulted from the addition of a PMDA-aniline additive to LARC-TPI. Solution viscosity studies imply that amic acid additives temporarily lower molecular weight and, hence, enlarge the processing window. Thus, compositions containing the additive have a lower melt viscosity for a longer time than those unmodified.

  20. Elements of an improved model of debris-flow motion

    USGS Publications Warehouse

    Iverson, R.M.

    2009-01-01

    A new depth-averaged model of debris-flow motion describes simultaneous evolution of flow velocity and depth, solid and fluid volume fractions, and pore-fluid pressure. Non-hydrostatic pore-fluid pressure is produced by dilatancy, a state-dependent property that links the depth-averaged shear rate and volumetric strain rate of the granular phase. Pore-pressure changes caused by shearing allow the model to exhibit rate-dependent flow resistance, despite the fact that the basal shear traction involves only rate-independent Coulomb friction. An analytical solution of simplified model equations shows that the onset of downslope motion can be accelerated or retarded by pore-pressure change, contingent on whether dilatancy is positive or negative. A different analytical solution shows that such effects will likely be muted if downslope motion continues long enough, because dilatancy then evolves toward zero, and volume fractions and pore pressure concurrently evolve toward steady states. ?? 2009 American Institute of Physics.

  1. Improved Flow-Field Structures for Direct Methanol Fuel Cells

    SciTech Connect

    Gurau, Bogdan

    2013-05-31

    The direct methanol fuel cell (DMFC) is ideal if high energy-density liquid fuels are required. Liquid fuels have advantages over compressed hydrogen including higher energy density and ease of handling. Although state-of-the-art DMFCs exhibit manageable degradation rates, excessive fuel crossover diminishes system energy and power density. Although use of dilute methanol mitigates crossover, the concomitant lowering of the gross fuel energy density (GFED) demands a complex balance-of-plant (BOP) that includes higher flow rates, external exhaust recirculation, etc. An alternative approach is redesign of the fuel delivery system to accommodate concentrated methanol. NuVant Systems Inc. (NuVant) will maximize the GFED by design and assembly of a DMFC that uses near neat methanol. The approach is to tune the diffusion of highly concentrated methanol (to the anode catalytic layer) to the back-diffusion of water formed at the cathode (i.e. in situ generation of dilute methanol at the anode layer). Crossover will be minimized without compromising the GFED by innovative integration of the anode flow-field and the diffusion layer. The integrated flow-field-diffusion-layers (IFDLs) will widen the current and potential DMFC operating ranges and enable the use of cathodes optimized for hydrogen-air fuel cells.

  2. Building block style recipes for productivity improvement in OPC, RET and ILT flows

    NASA Astrophysics Data System (ADS)

    Wu, Linghui; Kwa, Denny; Wan, Jinyin; Wang, Tom; St. John, Matt; Deeth, Steven; Chen, Xiaohui; Cecil, Tom; Meng, Xiaodong; Lucas, Kevin

    2016-03-01

    Traditional model-based Optical Proximity Correction (OPC) and rule-based Resolution Enhancement Technology (RET) methods have been the workhorse mask synthesis methods in volume production for logic and memory devices for more than 15 years. Rule-based OPC methods have been in standard use for over 20 years now. With continuous technical enhancements, these methods have proven themselves robust, flexible and fast enough to meet many of the technical needs of even the most advanced nodes. Inverse Lithography Technology (ILT) methods are well known to have strong benefits in finding flexible mask pattern solutions to improve process window for the most advanced design locations where traditional methods are not sufficient. However, OPC/RET requirements at each node have changed radically in the last 20 years beyond just technical requirements. The volume of engineering work to be done has also skyrocketed. The number of device layers which need OPC/RET can be 10X higher than in earlier nodes. Additionally, the number of mask layers per device layer is often 2X or more times higher with multiple patterning. Finally, the number of features to correct per mask increases ~2X with each node. These factors led to a large increase in the number of OPC engineers needed to develop the complex new OPC/RET recipes for advanced nodes. In this paper, we describe new developments which significantly improve the productivity of OPC engineers to deploy Rule Based OPC (RBOPC), Model Based OPC (MBOPC), AF, and ILT recipes in modern manufacturing flows. In addition to technical improvements such as novel multiple segment hotspot fixing solvers and ILT hot-spot fixing necessary to support correction needs, we have re-architected the entire flow based on how OPC engineers now develop and maintain OPC/RET recipes. The re-architecture of the flow takes advantages of more recent developments in modular and structured programming methods which are known to benefit ease engineering software

  3. Design of Flow Systems for Improved Networking and Reduced Noise in Biomolecular Signal Processing in Biocomputing and Biosensing Applications

    PubMed Central

    Verma, Arjun; Fratto, Brian E.; Privman, Vladimir; Katz, Evgeny

    2016-01-01

    We consider flow systems that have been utilized for small-scale biomolecular computing and digital signal processing in binary-operating biosensors. Signal measurement is optimized by designing a flow-reversal cuvette and analyzing the experimental data to theoretically extract the pulse shape, as well as reveal the level of noise it possesses. Noise reduction is then carried out numerically. We conclude that this can be accomplished physically via the addition of properly designed well-mixing flow-reversal cell(s) as an integral part of the flow system. This approach should enable improved networking capabilities and potentially not only digital but analog signal-processing in such systems. Possible applications in complex biocomputing networks and various sense-and-act systems are discussed. PMID:27399702

  4. Design of Flow Systems for Improved Networking and Reduced Noise in Biomolecular Signal Processing in Biocomputing and Biosensing Applications.

    PubMed

    Verma, Arjun; Fratto, Brian E; Privman, Vladimir; Katz, Evgeny

    2016-07-05

    We consider flow systems that have been utilized for small-scale biomolecular computing and digital signal processing in binary-operating biosensors. Signal measurement is optimized by designing a flow-reversal cuvette and analyzing the experimental data to theoretically extract the pulse shape, as well as reveal the level of noise it possesses. Noise reduction is then carried out numerically. We conclude that this can be accomplished physically via the addition of properly designed well-mixing flow-reversal cell(s) as an integral part of the flow system. This approach should enable improved networking capabilities and potentially not only digital but analog signal-processing in such systems. Possible applications in complex biocomputing networks and various sense-and-act systems are discussed.

  5. Additional tangential and normal stress close to the wall in the motion of a two-component flow

    SciTech Connect

    Beznosov, A.V.; Fedotovskii, V.S.; Orlov, S.Y.; Serov, V.E.

    1986-09-01

    Industrial tests of the cleaning of a T-100-130 turbine by a twocomponent condenser flow for sludgy deposits of thickness 0.5-1.2.10/sup -3/ m have been carried out for the operating conditions of water-circulation systems at atomic power plants. The additional pulsations of the tangential and normal stress arising in the deposits under the action of the water-air flow proved sufficient for their destruction. Visual inspection of the system after the tests showed the absence of deposits on the inlet sections of the forward and backward tubes and reduction in thickness of the deposits on the outlet sections to low values: (0.1-0.2) .10/sup -3/ m.

  6. The Role of Flow Field Computation in Improving Turbomachinery.

    DTIC Science & Technology

    1986-06-01

    sad total pressure within Solls-Royce t9 design turbine blade %hopes. loan. The comressors need in engines designed in Moruigesn and ReJily. 7 0 ) wrote... engine improve efficiency. In one case, blading designed specific fuel conaumption improved by some I Z. by NOTS for a mall Industrial turbine anufact...the corners Nost small aeronautical gas turbines have there- between wall and blade , and in due course also for fore chosen to use several axial stages

  7. Addition of meloxicam to the treatment of clinical mastitis improves subsequent reproductive performance.

    PubMed

    McDougall, S; Abbeloos, E; Piepers, S; Rao, A S; Astiz, S; van Werven, T; Statham, J; Pérez-Villalobos, N

    2016-03-01

    A blinded, negative controlled, randomized intervention study was undertaken to test the hypothesis that addition of meloxicam, a nonsteroidal anti-inflammatory drug, to antimicrobial treatment of mild to moderate clinical mastitis would improve fertility and reduce the risk of removal from the herd. Cows (n=509) from 61 herds in 8 regions (sites) in 6 European countries were enrolled. Following herd-owner diagnosis of mild to moderate clinical mastitis within the first 120 d of lactation in a single gland, the rectal temperature, milk appearance, and California Mastitis Test score were assessed. Cows were randomly assigned within each site to be treated either with meloxicam or a placebo (control). All cows were additionally treated with 1 to 4 intramammary infusions of cephalexin and kanamycin at 24-h intervals. Prior to treatment and at 14 and 21 d posttreatment, milk samples were collected for bacteriology and somatic cell count. Cows were bred by artificial insemination and pregnancy status was subsequently defined. General estimating equations were used to determine the effect of treatment (meloxicam versus control) on bacteriological cure, somatic cell count, the probability of being inseminated by 21 d after the voluntary waiting period, the probability of conception to first artificial insemination, the number of artificial insemination/conception, the probability of pregnancy by 120 or 200 d postcalving, and the risk of removal by 300 d after treatment. Cox's proportional hazards models were used to test the effect of treatment on the calving to first insemination and calving to conception intervals. Groups did not differ in terms of age, clot score, California Mastitis Test score, rectal temperature, number of antimicrobial treatments given or bacteria present at the time of enrollment, but cows treated with meloxicam had greater days in milk at enrollment. Cows treated with meloxicam had a higher bacteriological cure proportion than those treated with

  8. Applications of recently improved electronic speckle pattern interferometry by addition of incremental images

    NASA Astrophysics Data System (ADS)

    Hertwig, Manfred H. F.; Floureux, Thierry; Flemming, Torsten

    1994-12-01

    This paper demonstrates the advantages of a recently reported improved technique of phase- shifted electronic speckle interferometry. The improvement extends the range and enhances the accuracy of measurements and thus unlocks many new applications. One of these is detecting various types of fatigue damage in carbon-fiber-reinforced plastics (CFRP). The optical measurements of surface matrix cracks and of delaminations agree very well with the results of other non-destructive testing (NDT) methods. We also demonstrate an improved contouring technique and present the theory behind the experimental procedure, leading to the improved results reported here.

  9. Review of passive shear-flow control research for improved subsonic and supersonic combustion

    SciTech Connect

    Schadow, K.C.; Gutmark, E.

    1989-01-01

    Shear-flow investigations have been conducted in the high-Re, turbulent initial-condition combustion regime representative of flow configurations encountered in ramjets and in supersonic plumes. Large-scale vortical structures were identified and characterized in both nonreacting and combustion-reaction experimental conditions; attention was given to these structures' role in mixing, and their breakup into fine-scale turbulence. Shear-flow/combustion control was obtained by actively enlisting duct acoustics and passively employing noncircular flow cross-sections. The investigations were extended to supersonic shear flows, yielding improved mixing for supersonic combustion. 44 refs.

  10. Improved Flux Formulations for Unsteady Low Mach Number Flows

    DTIC Science & Technology

    2012-06-01

    flows (as, for example, the combusted exhaust plume from an aircraft engine). One effective way for expressing a general iterative method is through a...pseudo-Mach number to physical-Mach number and the ratio of specific heats : 2 1 1p p p M M (5) where 2 2 2 2 minmin max( , , ),1p i uM M M M (6...performed with the CRUNCH CFD ® code, developed at CRAFT Tech12-15. The candidate flux formulations for unsteady low Mach 8 American Institute of

  11. Improvement of transient stability using unified power flow controller

    SciTech Connect

    Mihalic, R.; Zunko, P.; Povh, D.

    1996-01-01

    The aim of the paper is to analyze the effect of an Unified Power Flow Controller (UPFC) on transient stability margin enhancement of a longitudinal system. To utilize the UPFC possibilities fully, the three controllable UPFC parameters were determined during the digital simulation process performed by the NETOMAC simulation program. The basis for determination of the suitable damping strategy and for determination of the optimal UPFC parameters is a mathematical model, which describes the interdependence between longitudinal transmission system parameters, operating conditions and UPFC parameters in the form of analytical equations. On the basis of the mathematical model, the theoretical UPFC limits were also detected, and their appearance explained.

  12. Improved Turbine Blade Cooling Using Endwall Flow Modifications

    DTIC Science & Technology

    2007-11-02

    ANEMOMETER AND PROBE 21 3.3 PRESSURE TRANSDUCER 22 3.4 PITOT TUBE 23 3.5 KIEL PROBE 23 3.6 LASER DOPPLER ANEMOMETRY 24 4 FLOW VISUALIZATION 26 4.1 OIL AND...blades and nozzle vanes ) and the endwalls (Ito, 1978). One common cooling method is "film cooling" in which cool air is bled from the compressor and...demodulator outputs to a voltage which is proportional to the pressure difference across the diaphragm. A pitot tube was placed in the wind tunnel and

  13. Tank mixture additives approach to improve efficiency of bentazon against broadleaf weeds in peas.

    PubMed

    Balah, Mohamed A; Hanafi, Ahmad; Ghani, Sherif B Abdel

    2012-01-01

    Efficiency of different tank-mixed additives with bentazon at half rate was investigated on (Malva parviflora) and other broad leaf weeds compared with bentazon at the full recommended rate without additives in peas in open field. All the tested additives enhanced the efficiency of bentazon at the half rate. Nonyl phenol and toximol S proved to be the most effective additives in comparison with the full rate treatment. The tested treatments did not show any significant effect on chlorophyll content and soil microorganisms. Bentazon residues were determined in certain treatments to investigate the effect of the tested additives on bentazon deposition. Samples were extracted using QuEChERS method and residues were determined using LC-MS/MS. Residues after 24 hours in the half rate treatment reached 4 times lower than the Maximum Residues Limit (MRL) (0.11 mg kg(-1)), compared to the full rate treatment (0.51 mg kg(-1)), that was slightly above the MRL.

  14. Improving the performance of biomimetic hair-flow sensors by electrostatic spring softening

    NASA Astrophysics Data System (ADS)

    Droogendijk, H.; Bruinink, C. M.; Sanders, R. G. P.; Dagamseh, A. M. K.; Wiegerink, R. J.; Krijnen, G. J. M.

    2012-06-01

    We report improvements in the detection limit and responsivity of biomimetic hair-flow sensors by electrostatic spring softening. Applying a dc-bias voltage to our capacitive flow sensors results in a reduced sensory threshold, improving the mechanical transfer and flow detection limit by more than 6 dB. We further show that the sensor's responsivity for airflows is also improved on application of high-frequency ac-bias voltages to the sensor's capacitive structures with little sensitivity to the bias frequency.

  15. An improved flow cytometry assay to monitor phagosome acidification.

    PubMed

    Colas, Chloé; Menezes, Shinelle; Gutiérrez-Martínez, Enric; Péan, Claire B; Dionne, Marc S; Guermonprez, Pierre

    2014-10-01

    Phago-lysosome formation is important for cell-autonomous immunity to intracellular pathogens, antigen presentation and metabolism. A hallmark feature of phago-lysosomal compartments is that they undergo progressive luminal acidification controlled by the activation of vacuolar V-ATPase. Acidification is required for many enzymatic processes taking place in phago-lysosomes, like proteolysis, and supports the microbicidal activity of macrophages. Here we present a new quantitative methodology to assess phagosome acidification by flow cytometry based on the use of bi-fluorescent particles. This method relies on the use of UV polystyrene beads labelled with the acid sensor pHrodo-succinimidyl ester (pHrodo(TM) SE red) and enables us to dissociate particle association with phagocytes from their engulfment in acidified compartments. This methodology is well suited to monitor the acidification of phagosomes formed in vivo after fluorescent bead administration.

  16. MoFlow: visualizing conformational changes in molecules as molecular flow improves understanding

    PubMed Central

    2015-01-01

    Background Current visualizations of molecular motion use a Timeline-analogous representation that conveys "first the molecule was shaped like this, then like this...". This scheme is orthogonal to the Pathline-like human understanding of motion "this part of the molecule moved from here to here along this path". We present MoFlow, a system for visualizing molecular motion using a Pathline-analogous representation. Results The MoFlow system produces high-quality renderings of molecular motion as atom pathlines, as well as interactive WebGL visualizations, and 3D printable models. In a preliminary user study, MoFlow representations are shown to be superior to canonical representations for conveying molecular motion. Conclusions Pathline-based representations of molecular motion are more easily understood than timeline representations. Pathline representations provide other advantages because they represent motion directly, rather than representing structure with inferred motion. PMID:26361501

  17. Report: Additional Efforts Needed to Improve EPA’s Oversight of Assistance Agreements

    EPA Pesticide Factsheets

    Report #2002-P-00018, September 30, 2002. Although EPA developed corrective actions to improve oversight controls for assistance agreements, a number of EPA OIG, Agency, and GAO reviews determined that oversight continued to be a weakness.

  18. Process for improving mechanical properties of epoxy resins by addition of cobalt ions

    NASA Technical Reports Server (NTRS)

    Stoakley, D. M.; St.clair, A. K. (Inventor)

    1984-01-01

    A resin product useful as an adhesive, composite or casting resin is described as well as the process used in its preparation to improve its flexural strength mechanical property characteristics. Improved flexural strength is attained with little or no change in density, thermal stability or moisture resistance by chemically incorporating 1.2% to 10.6% by weight Co(3) ions in an epoxidized resin system.

  19. Hierarchical random additive process and logarithmic scaling of generalized high order, two-point correlations in turbulent boundary layer flow

    NASA Astrophysics Data System (ADS)

    Yang, X. I. A.; Marusic, I.; Meneveau, C.

    2016-06-01

    Townsend [Townsend, The Structure of Turbulent Shear Flow (Cambridge University Press, Cambridge, UK, 1976)] hypothesized that the logarithmic region in high-Reynolds-number wall-bounded flows consists of space-filling, self-similar attached eddies. Invoking this hypothesis, we express streamwise velocity fluctuations in the inertial layer in high-Reynolds-number wall-bounded flows as a hierarchical random additive process (HRAP): uz+=∑i=1Nzai . Here u is the streamwise velocity fluctuation, + indicates normalization in wall units, z is the wall normal distance, and ai's are independently, identically distributed random additives, each of which is associated with an attached eddy in the wall-attached hierarchy. The number of random additives is Nz˜ln(δ /z ) where δ is the boundary layer thickness and ln is natural log. Due to its simplified structure, such a process leads to predictions of the scaling behaviors for various turbulence statistics in the logarithmic layer. Besides reproducing known logarithmic scaling of moments, structure functions, and correlation function [" close="]3/2 uz(x ) uz(x +r ) >, new logarithmic laws in two-point statistics such as uz4(x ) > 1 /2, 1/3, etc. can be derived using the HRAP formalism. Supporting empirical evidence for the logarithmic scaling in such statistics is found from the Melbourne High Reynolds Number Boundary Layer Wind Tunnel measurements. We also show that, at high Reynolds numbers, the above mentioned new logarithmic laws can be derived by assuming the arrival of an attached eddy at a generic point in the flow field to be a Poisson process [Woodcock and Marusic, Phys. Fluids 27, 015104 (2015), 10.1063/1.4905301]. Taken together, the results provide new evidence supporting the essential ingredients of the attached eddy hypothesis to describe streamwise velocity fluctuations of large, momentum transporting eddies in wall-bounded turbulence, while

  20. An Improved Lattice Kinetic Scheme for Incompressible Viscous Fluid Flows

    NASA Astrophysics Data System (ADS)

    Suzuki, Kosuke; Inamuro, Takaji

    2014-01-01

    The lattice Boltzmann method (LBM) is an explicit numerical scheme for the incompressible Navier-Stokes equations (INSE) without integrating the Poisson equation for the pressure. In spite of its merit, the LBM has some drawbacks in accuracy. First, we review drawbacks for three numerical methods based on the LBM. The three methods are the LBM with the Bhatnagar-Gross-Krook model (LBGK), the lattice kinetic scheme (LKS) and the link-wise artificial compressibility method (LWACM). Second, in order to remedy the drawbacks, we propose an improved LKS. The present method incorporates (i) the scheme used in the LWACM for determining the kinematic viscosity, (ii) an iterative calculation of the pressure and (iii) a semi-implicit algorithm, while preserving the simplicity of the algorithm of the original LKS. Finally, in simulations of test problems, we find that the improved LKS eliminates the drawbacks and gives more accurate and stable results than LBGK, LKS and LWACM.

  1. Using Sap Flow Monitoring for Improved Process-based Ecohydrologic Understanding 2022

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sap flow measurements can be an important tool for unraveling the complex web of ecosystem fluxes, especially when it is combined with other measurements like eddy covariance, isotopes, remote sensing, etc. In this talk, we will demonstrate how sap flow measurements have improved our process-level u...

  2. Coal flow aids reduce coke plant operating costs and improve production rates

    SciTech Connect

    Bedard, R.A.; Bradacs, D.J.; Kluck, R.W.; Roe, D.C.; Ventresca, B.P.

    2005-06-01

    Chemical coal flow aids can provide many benefits to coke plants, including improved production rates, reduced maintenance and lower cleaning costs. This article discusses the mechanisms by which coal flow aids function and analyzes several successful case histories. 2 refs., 10 figs., 1 tab.

  3. Improving aerobic stability and biogas production of maize silage using silage additives.

    PubMed

    Herrmann, Christiane; Idler, Christine; Heiermann, Monika

    2015-12-01

    The effects of air stress during storage, exposure to air at feed-out, and treatment with silage additives to enhance aerobic stability on methane production from maize silage were investigated at laboratory scale. Up to 17% of the methane potential of maize without additive was lost during seven days exposure to air on feed-out. Air stress during storage reduced aerobic stability and further increased methane losses. A chemical additive containing salts of benzoate and propionate, and inoculants containing heterofermentative lactic acid bacteria were effective to increase aerobic stability and resulted in up to 29% higher methane yields after exposure to air. Exclusion of air to the best possible extent and high aerobic stabilities should be primary objectives when ensiling biogas feedstocks.

  4. LJUBLJANICA CONNECTS - Restoration of the Ljubljanica River corridor and improvement of the river's flow regime

    NASA Astrophysics Data System (ADS)

    Zabret, Katarina; Sapač, Klaudija; Šraj, Mojca; Bezak, Nejc; Sečnik, Matej; Vidmar, Andrej; Brilly, Mitja

    2016-04-01

    The project Ljubljanica connects is focused on improving connectivity and living conditions in Ljubljanica River which flows through capital city of Slovenia, Ljubljana. It represents living environment for endangered and Natura 2000 targeted fish species Danube Salmon (Hucho hucho), Danube Roach (Rutilus pigus) and Striped Chub (Leuciscus souffia). The project consists of four sets of activities: concrete restoration actions including improvement of two fish passes, monitoring of fish migration, monitoring of eco-hydrological parameters, and raising of public awareness. To improve living conditions the concrete restoration measures were performed. The reconstructions of sill and two fish passes on the Ljubljanica River have been implemented and barrier's lifting system on the weir was modernized. Above the sill in Zalog there is an oxbow which was disconnected with main river channel during the low flows. Interrupted inflow of fresh water caused very poor living conditions for animals in the oxbow. The raise of the sill helped to improve this situation. One of the fish passes included in the project is more than 100 years old whereas both are protected as cultural and technical heritage. None was working properly and due to the protection no visible nor drastic measures were allowed. With smaller improvements we managed to re-establish their operation. A lifting system of the barrier at the Ambrožev trg gate was outdated and did not allow precise regulation of the water level. Too fast raising of the barrier instantly caused deterioration of eco-hydrological conditions downstream. With modernization of the electromechanical equipment the situation is improved. The fish monitoring helps us to evaluate success of concrete restoration actions. The fish population status is monitored with marking the fish with Visible Implant Elastomer (VIE) tags. Regarding the location of catch we implant tags beneath transparent or translucent tissue combining different tag

  5. Yield Improvement and Energy Savings Uing Phosphonates as Additives in Kraft pulping

    SciTech Connect

    Ulrike W. Tschirner; Timothy Smith

    2007-03-31

    Project Objective: Develop a commercially viable modification to the Kraft process resulting in energy savings, increased yield and improved bleachability. Evaluate the feasibility of this technology across a spectrum of wood species used in North America. Develop detailed fundamental understanding of the mechanism by which phosphonates improve KAPPA number and yield. Evaluate the North American market potential for the use of phosphonates in the Kraft pulping process. Examine determinants of customer perceived value and explore organizational and operational factors influencing attitudes and behaviors. Provide an economic feasibility assessment for the supply chain, both suppliers (chemical supply companies) and buyers (Kraft mills). Provide background to most effectively transfer this new technology to commercial mills.

  6. Nattokinase improves blood flow by inhibiting platelet aggregation and thrombus formation

    PubMed Central

    Jang, Ja-Young; Kim, Tae-Su; Cai, Jingmei; Kim, Jihyun; Kim, Youngeun; Shin, Kyungha; Kim, Kwang Sei; Park, Sung Kyeong; Lee, Sung-Pyo; Choi, Ehn-Kyoung

    2013-01-01

    The effects of nattokinase on the in vitro platelet aggregation and in vivo thrombosis were investigated in comparison with aspirin. Rabbit platelet-rich plasma was incubated with nattokinase and aggregation inducers collagen and thrombin, and the platelet aggregation rate was analyzed. Nattokinase significantly inhibited both the collagen- and thrombin-induced platelet aggregations. Nattokinase also reduced thromboxane B2 formation from collagen-activated platelets in a concentration-dependent manner. Rats were orally administered with nattokinase for 1 week, and their carotid arteries were exposed. Arterial thrombosis was induced by applying 35% FeCl3-soaked filter paper for 10 min, and the blood flow was monitored with a laser Doppler probe. Nattokinase delayed the FeCl3-induced arterial occlusion in a dose-dependent manner, doubling the occlusion time at 160 mg/kg. In addition, a high dose (500 mg/kg) of nattokinase fully prevented the occlusion, as achieved with aspirin (30 mg/kg). The results indicate that nattokinase extracted from fermented soybean inhibit platelet aggregation by blocking thromboxane formation, and thereby delay thrombosis following oxidative arterial wall injury. Therefore, it is suggested that nattokinase could be a good candidate without adverse effects for the improvement of blood flow. PMID:24396387

  7. Nattokinase improves blood flow by inhibiting platelet aggregation and thrombus formation.

    PubMed

    Jang, Ja-Young; Kim, Tae-Su; Cai, Jingmei; Kim, Jihyun; Kim, Youngeun; Shin, Kyungha; Kim, Kwang Sei; Park, Sung Kyeong; Lee, Sung-Pyo; Choi, Ehn-Kyoung; Rhee, Man Hee; Kim, Yun-Bae

    2013-12-01

    The effects of nattokinase on the in vitro platelet aggregation and in vivo thrombosis were investigated in comparison with aspirin. Rabbit platelet-rich plasma was incubated with nattokinase and aggregation inducers collagen and thrombin, and the platelet aggregation rate was analyzed. Nattokinase significantly inhibited both the collagen- and thrombin-induced platelet aggregations. Nattokinase also reduced thromboxane B2 formation from collagen-activated platelets in a concentration-dependent manner. Rats were orally administered with nattokinase for 1 week, and their carotid arteries were exposed. Arterial thrombosis was induced by applying 35% FeCl3-soaked filter paper for 10 min, and the blood flow was monitored with a laser Doppler probe. Nattokinase delayed the FeCl3-induced arterial occlusion in a dose-dependent manner, doubling the occlusion time at 160 mg/kg. In addition, a high dose (500 mg/kg) of nattokinase fully prevented the occlusion, as achieved with aspirin (30 mg/kg). The results indicate that nattokinase extracted from fermented soybean inhibit platelet aggregation by blocking thromboxane formation, and thereby delay thrombosis following oxidative arterial wall injury. Therefore, it is suggested that nattokinase could be a good candidate without adverse effects for the improvement of blood flow.

  8. Time Domain Transformations to Improve Hydrologic Model Consistency: Parameterization in Flow-Corrected Time

    NASA Astrophysics Data System (ADS)

    Smith, T. J.; Marshall, L. A.; McGlynn, B. L.

    2015-12-01

    Streamflow modeling is highly complex. Beyond the identification and mapping of dominant runoff processes to mathematical models, additional challenges are posed by the switching of dominant streamflow generation mechanisms temporally and dynamic catchment responses to precipitation inputs based on antecedent conditions. As a result, model calibration is required to obtain parameter values that produce acceptable simulations of the streamflow hydrograph. Typical calibration approaches assign equal weight to all observations to determine the best fit over the simulation period. However, the objective function can be biased toward (i.e., implicitly weight) certain parts of the hydrograph (e.g., high streamflows). Data transformations (e.g., logarithmic or square root) scale the magnitude of the observations and are commonly used in the calibration process to reduce implicit weighting or better represent assumptions about the model residuals. Here, we consider a time domain data transformation rather than the more common data domain approaches. Flow-corrected time was previously employed in the transit time modeling literature. Conceptually, it stretches time during high streamflow and compresses time during low streamflow periods. Therefore, streamflow is dynamically weighted in the time domain, with greater weight assigned to periods with larger hydrologic flux. Here, we explore the utility of the flow-corrected time transformation in improving model performance of the Catchment Connectivity Model. Model process fidelity was assessed directly using shallow groundwater connectivity data collected at Tenderfoot Creek Experimental Forest. Our analysis highlights the impact of data transformations on model consistency and parameter sensitivity.

  9. Addition of glucose oxidase for the improvement of refrigerated dough quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Refrigerated dough encompasses a wide range of products and is a very popular choice for consumers. Two of the largest problems that occur during refrigerated dough storage are dough syruping and loss of dough strength. The goal of this study was to evaluate glucose oxidase as an additive to refri...

  10. Improving Student Understanding of Addition of Angular Momentum in Quantum Mechanics

    ERIC Educational Resources Information Center

    Zhu, Guangtian; Singh, Chandralekha

    2013-01-01

    We describe the difficulties advanced undergraduate and graduate students have with concepts related to addition of angular momentum in quantum mechanics. We also describe the development and implementation of a research-based learning tool, Quantum Interactive Learning Tutorial (QuILT), to reduce these difficulties. The preliminary evaluation…

  11. Lewis base additives improve the zeolite ferrierite-catalyzed synthesis of isostearic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Isostearic acid (IA) is of interest for industrial purposes especially in the area of biolubricants, such as cosmetics and slip additives for polyolefin and related copolymer films. This study was designed to develop a zeolitic catalysis process for IA production through isomerization of fatty aci...

  12. Improved numerical methods for turbulent viscous flows aerothermal modeling program, phase 2

    NASA Technical Reports Server (NTRS)

    Karki, K. C.; Patankar, S. V.; Runchal, A. K.; Mongia, H. C.

    1988-01-01

    The details of a study to develop accurate and efficient numerical schemes to predict complex flows are described. In this program, several discretization schemes were evaluated using simple test cases. This assessment led to the selection of three schemes for an in-depth evaluation based on two-dimensional flows. The scheme with the superior overall performance was incorporated in a computer program for three-dimensional flows. To improve the computational efficiency, the selected discretization scheme was combined with a direct solution approach in which the fluid flow equations are solved simultaneously rather than sequentially.

  13. Improved flow characteristics of bauxite by treatment with a bauxite handling aid

    SciTech Connect

    Cardounel, C.; O`Brien, K.

    1996-10-01

    Sherwin Plant bauxite handling facilities are capable of processing relatively free flowing dry bauxites. The processing of wet bauxite through these facilities was challenging and required the use of backhoes and bulldozers. The use of a bauxite handling aid to enhance flow properties of wet bauxite was investigated in the laboratory and subsequently tested in the plant. A significant improvement in flow characteristics was achieved. The bauxite became free flowing, eliminating the need for backhoes and bulldozers to reclaim the bauxite. This paper relates how laboratory testing led to successful plant application of the bauxite handling aid.

  14. Modification of silicone sealant to improve gamma radiation resistance, by addition of protective agents

    NASA Astrophysics Data System (ADS)

    González-Pérez, Giovanni; Burillo, Guillermina

    2013-09-01

    Poly (dimethylsiloxane) (PDMS) sealant (SS) was modified with the addition of different protective compounds to conserve its physical-chemical properties during gamma irradiation. 2-Vinyl naphthalene (2-VN), bisphenol-A (BPA) and poly (vinyl carbazole) (PVK) were used to evaluate radiation protection through the crosslinking effect of radiation. The samples were irradiated with doses from 100 kGy to 500 kGy at room temperature in air, with a 60Co gamma source, and the changes in molecular weight, thermal behavior, elastic properties and infrared spectra (FTIR-ATR) absorbance analysis were determined. The molecular weight of unmodified silicone sealant increases with the absorbed dose because of crosslinking as predominant effect. However, the crosslinking effect was inhibited with the addition of protective agent due to the aromatic compounds present. Modified silicone sealant films present better radiation resistance than unmodified system.

  15. Improved adhesive strength and toughness of polyvinyl acetate glue on addition of small quantities of graphene.

    PubMed

    Khan, Umar; May, Peter; Porwal, Harshit; Nawaz, Khalid; Coleman, Jonathan N

    2013-02-01

    We have prepared composites of polyvinyl acetate (PVAc) reinforced with solution exfoliated graphene. We observe a 50% increase in stiffness and a 100% increase in tensile strength on addition of 0.1 vol % graphene compared to the pristine polymer. As PVAc is commonly used commercially as a glue, we have tested such composites as adhesives. The adhesive strength and toughness of the composites were up to 4 and 7 times higher, respectively, than the pristine polymer.

  16. Improvement of the superconducting properties of polycrystalline FeSe by silver addition

    NASA Astrophysics Data System (ADS)

    Nazarova, E.; Balchev, N.; Nenkov, K.; Buchkov, K.; Kovacheva, D.; Zahariev, A.; Fuchs, G.

    2015-12-01

    We investigated the influence of different Ag additions (up to 10 wt%) on the superconducting properties of FeSe0.94. The structural investigations (XRD and SEM) indicated that Ag is present in three different forms. Ag at grain boundaries supports the excellent intergrain connections and reduces ΔT to values smaller than 1 K at B = 0 and ΔT ≤ 2.74 K at B = 14 T. Ag insertion in the crystal lattice unit cell provides additional carriers and changes the electron-hole imbalance in FeSe0.94. This results in an increase in the magnetoresistive effect (MR) and critical temperature (T c). Reacted Ag forms a small amount (˜1%) of Ag2Se impurity phase, which may increase the pinning energy in comparison with that of the undoped sample. The enhanced upper critical field (B c2) is also a result of the increased impurity scattering. Thus, unlike cuprates, Ag addition enhances the T c, B c2, pinning energy and MR making the properties of polycrystalline FeSe0.94 similar to those of single crystals.

  17. Improvement of organics removal by bio-ceramic filtration of raw water with addition of phosphorus.

    PubMed

    Sang, Junqiang; Zhang, Xihui; Li, Lingzhi; Wang, Zhansheng

    2003-11-01

    The purpose of this study was to investigate the effect of phosphorus addition on biological pretreatment of raw water. Experiments were conducted in pilot-scale bio-ceramic filters with raw water from a reservoir located in Beijing, China. The results demonstrated that phosphorus was the limiting nutrient for bacterial growth in the raw water investigated in this study. The measured values of bacterial regrowth potential (BRP) and biodegradable dissolved organic carbon (BDOC) of the raw water increased by 50-65% and 30-40% with addition of 50 microg of PO4(3-)-PL(-1), respectively. Addition of 25 microg of PO4(3-)-PL(-1) to the influent of bio-ceramic filter enhanced the percent removal of organics by 4.6, 5.7 and 15 percentage points in terms of COD(Mn), TOC and BDOC, respectively. Biomass in terms of phospholipid content increased by 13-22% and oxygen uptake rate (OUR) increased by 35-45%. The ratio of C:P for bacteria growth was 100:1.6 for the raw water used in this study. Since change of phosphorus concentrations can influence the performance of biological pretreatment and the biological stability of drinking water, this study is of substantial significance for waterworks in China. The role of phosphorus in biological processes of drinking water should deserve more attention.

  18. Improvement of the quality of wheat bread by addition of glycoside hydrolase family 10 xylanases.

    PubMed

    Zheng, Han; Guo, Bing; Chen, Xiu-Lan; Fan, Sou-Jin; Zhang, Yu-Zhong

    2011-04-01

    Although many xylanases are widely used in the baking industry, only one glycoside hydrolase family 10 (GH 10) xylanase has previously been reported to be effective in baking. In this study, we compared the effectiveness of two GH 10 xylanases, psychrophilic XynA from Glaciecola mesophila and mesophilic EX1 from Trichoderma pseudokoningii, in bread making. The optimal dosages needed to improve wheat flour dough and bread quality were 270-U/kg flour for EX1 and 0.9-U/kg flour for XynA. At their optimal dosage, both XynA and EX1 had significant dough-softening ability, resulting in a 50% reduction in Brabender units. XynA was more effective than EX1 in reducing the time to reach maximum consistency. XynA and EX1 showed similar effects in improving the bread volume (~30% increase). EX1 was more effective in reducing the initial crumb firmness. Although both enzymes exhibited similar anti-staling effects on the bread, based on a decrease in the bread firmness, XynA had a greater effect on reducing the firming rate, and EX1 showed an enhanced reduction in the initial firmness. These results show that these two GH 10 xylanases have unique advantages in improving dough and bread quality and indicate their potential in bread making.

  19. Improved lattice Boltzmann model for multi-component diffusion flow with large pressure difference

    NASA Astrophysics Data System (ADS)

    Liu, Fu-Min; Wang, An-Lin; Qiu, Ruo-Fan; Jiang, Tao

    2016-05-01

    The pseudopotential lattice Boltzmann model has been widely used to solve multi-phase and multi-component flow problems. However, original pseudopotential model cannot be used in simulating diffusion flow with large pressure difference because of its limitation. In this paper, we incorporate pseudopotential model with a new form of effective mass to solve this problem based on the relationship between pressure difference and effective mass. The improved model is verified through Laplace’s law and binary immiscible Poiseuille flow. By simulating pipeline binary diffusion flow and two-inlet binary cavity jet flow, we show that the improved model can achieve larger pressure difference than pseudopotential model with traditional effective mass forms.

  20. Post Processing Methods used to Improve Surface Finish of Products which are Manufactured by Additive Manufacturing Technologies: A Review

    NASA Astrophysics Data System (ADS)

    Kumbhar, N. N.; Mulay, A. V.

    2016-08-01

    The Additive Manufacturing (AM) processes open the possibility to go directly from Computer-Aided Design (CAD) to a physical prototype. These prototypes are used as test models before it is finalized as well as sometimes as a final product. Additive Manufacturing has many advantages over the traditional process used to develop a product such as allowing early customer involvement in product development, complex shape generation and also save time as well as money. Additive manufacturing also possess some special challenges that are usually worth overcoming such as Poor Surface quality, Physical Properties and use of specific raw material for manufacturing. To improve the surface quality several attempts had been made by controlling various process parameters of Additive manufacturing and also applying different post processing techniques on components manufactured by Additive manufacturing. The main objective of this work is to document an extensive literature review in the general area of post processing techniques which are used in Additive manufacturing.

  1. Improved Soft Abrasive Flow Finishing Method Based on Turbulent Kinetic Energy Enhancing

    NASA Astrophysics Data System (ADS)

    LI, Jun; JI, Shiming; TAN, Dapeng

    2017-03-01

    Soft abrasive flow(SAF) finishing can process the irregular geometric surfaces, but with the matter of low processing efficiency. To address the issue, an improved SAF finishing method based on turbulent kinetic energy enhancing is proposed. A constrained flow passage with serration cross-section is constructed to increase the turbulence intensity. Taking the constrained flow passage as the objective, a two-phase fluid dynamic model is set up by using particle trajectory model and standard k-ɛ turbulence model, and the flow field characteristics of the flow passage are acquired. The numerical results show that the serration flow passage can enhance the turbulence intensity, uniform the particles distribution, and increase the particle concentration near the bottom wall. The observation results by particle image velocimetry(PIV) show that the internal vortex structures are formed in flow passage, and the abrasive flow takes on turbulence concentrating phenomenon in near-wall region. The finishing experiments prove that the proposed method can obtain better surface uniformity, and the processing efficiency can be improved more 35%. This research provides an abrasive flow modeling method to reveal the particle motion regulars, and can offer references to the technical optimization of fluid-based precision processing.

  2. High Sensitivity Carbon Nanotubes Flow-Rate Sensors and Their Performance Improvement by Coating

    PubMed Central

    Yang, Xing; Zhou, Zhaoying; Wang, Dingqu; Liu, Xiaoli

    2010-01-01

    A new type of hot-wire flow-rate sensor (HWFS) with a sensing element made of a macro-sized carbon nanotube (CNT) strand is presented in this study. An effective way to improve repeatability of the CNT flow-rate sensor by coating a layer of Al2O3 on the CNT surface is proposed. Experimental results show that due to the large surface-to-volume ratio and thin coated Al2O3 layer, the CNT flow-rate sensor has higher sensitivity and faster response than a conventional platinum (Pt) HWFS. It is also demonstrated that the covered CNT flow-rate sensor has better repeatability than its bare counterpart due to insulation from the surrounding environment. The proposed CNT flow-rate sensor shows application potential for high-sensitivity measurement of flow rate. PMID:22399913

  3. An Additive to Improve the Wear Characteristics of Perfluoropolyether Based Greases

    NASA Technical Reports Server (NTRS)

    Jones, David G. V.; Fowzy, Mahmoud A.; Landry, James F.; Jones, William R., Jr.; Shogrin, Bradley A.; Nguyen, QuynhGiao

    1999-01-01

    The friction and wear characteristics of two formulated perfluoropolyether based greases were compared to their non-additive base greases. One grease was developed for the electronics industry (designated as GXL-296A) while the other is for space applications (designated as GXL-320A). The formulated greases (GXL-296B and GXL-320B) contained a proprietary antiwear additive at an optimized concentration. Tests were conducted using a vacuum four-ball tribometer. AISI 52100 steel specimens were used for all GXL-296 tests. Both AISI 52100 steel and 440C stainless steel were tested with the GXL-320 greases. Test conditions included: a pressure less than 6.7 x 10(exp )-4 Pa, a 200N load, a sliding velocity of 28.8 mm/sec (100 rpm) and room temperature (approximately equal to 23 C). Wear rates for each grease were determined from the slope of the wear volume as a function of sliding distance. Both non-additive base greases yielded relatively high wear rates on the order of 10(exp -8) cu mm using AISI 52100 steel specimens. Formulated grease GXL-296B yielded a reduction in wear rate by a factor of approximately 21, while grease GXL-320B had a reduction of approximately 12 times. Lower wear rates (-50%) were observed with both GXL-320 greases using 440C stainless steel. Mean friction coefficients were slightly higher for both formulated greases compared to their base greases. The GXL-296 series (higher base oil viscosity) yielded much higher friction coefficients compared to their GXL-320 series (lower base oil viscosity) counterparts.

  4. Evaluation Of Electrochemical Machining Technology For Surface Improvements In Additive Manufactured Components

    SciTech Connect

    Dehoff, Ryan R.; List, III, Frederick Alyious; Carver, Keith

    2015-09-23

    ORNL Manufacturing Demonstration Facility worked with ECM Technologies LLC to investigate the use of precision electro-chemical machining technology to polish the surface of parts created by Arcam electron beam melting. The goals for phase one of this project have been met. The project goal was to determine whether electro-chemical machining is a viable method to improve the surface finish of Inconel 718 parts fabricated using the Arcam EBM method. The project partner (ECM) demonstrated viability for parts of both simple and complex geometry. During the course of the project, detailed process knowledge was generated. This project has resulted in the expansion of United States operations for ECM Technologies.

  5. Hemolysate-mediated platelet aggregation: an additional risk mechanism contributing to thrombosis of continuous flow ventricular assist devices.

    PubMed

    Tran, Phat L; Pietropaolo, Maria-Grazia; Valerio, Lorenzo; Brengle, William; Wong, Raymond K; Kazui, Toshinobu; Khalpey, Zain I; Redaelli, Alberto; Sheriff, Jawaad; Bluestein, Danny; Slepian, Marvin J

    2016-07-01

    Despite the clinical success and growth in the utilization of continuous flow ventricular assist devices (cfVADs) for the treatment of advanced heart failure, hemolysis and thrombosis remain major limitations. Inadequate and/or ineffective anticoagulation regimens, combined with high pump speed and non-physiological flow patterns, can result in hemolysis which often is accompanied by pump thrombosis. An unexpected increase in cfVADs thrombosis was reported by multiple major VAD implanting centers in 2014, highlighting the association of hemolysis and a rise in lactate dehydrogenase (LDH) presaging thrombotic events. It is well established that thrombotic complications arise from the abnormal shear stresses generated by cfVADs. What remains unknown is the link between cfVAD-associated hemolysis and pump thrombosis. Can hemolysis of red blood cells (RBCs) contribute to platelet aggregation, thereby, facilitating prothrombotic complications in cfVADs? Herein, we examine the effect of RBC-hemolysate and selected major constituents, i.e., lactate dehydrogenase (LDH) and plasma free hemoglobin (pHb) on platelet aggregation, utilizing electrical resistance aggregometry. Our hypothesis is that elements of RBCs, released as a result of shear-mediated hemolysis, will contribute to platelet aggregation. We show that RBC hemolysate and pHb, but not LDH, are direct contributors to platelet aggregation, posing an additional risk mechanism for cfVAD thrombosis.

  6. Ionic liquids in chromatographic and electrophoretic techniques: toward additional improvements in the separation of natural compounds

    PubMed Central

    Freire, Carmen S. R.; Coutinho, João A. P.; Silvestre, Armando J. D.; Freire, Mara G.

    2016-01-01

    Due to their unique properties, in recent years, ionic liquids (ILs) have been largely investigated in the field of analytical chemistry. Particularly during the last sixteen years, they have been successfully applied in the chromatographic and electrophoretic analysis of value-added compounds extracted from biomass. Considering the growing interest in the use of ILs in this field, this critical review provides a comprehensive overview on the improvements achieved using ILs as constituents of mobile or stationary phases in analytical techniques, namely in capillary electrophoresis and its different modes, in high performance liquid chromatography, and in gas chromatography, for the separation and analysis of natural compounds. The impact of the IL chemical structure and the influence of secondary parameters, such as the IL concentration, temperature, pH, voltage and analysis time (when applied), are also critically addressed regarding the achieved separation improvements. Major conclusions on the role of ILs in the separation mechanisms and the performance of these techniques in terms of efficiency, resolution and selectivity are provided. Based on a critical analysis of all published results, some target-oriented ILs are suggested. Finally, current drawbacks and future challenges in the field are highlighted. In particular, the design and use of more benign and effective ILs as well as the development of integrated (and thus more sustainable) extraction–separation processes using IL aqueous solutions are suggested within a green chemistry perspective. PMID:27667965

  7. Ionic liquids in chromatographic and electrophoretic techniques: toward additional improvements in the separation of natural compounds.

    PubMed

    Soares, Belinda; Passos, Helena; Freire, Carmen S R; Coutinho, João A P; Silvestre, Armando J D; Freire, Mara G

    2016-09-07

    Due to their unique properties, in recent years, ionic liquids (ILs) have been largely investigated in the field of analytical chemistry. Particularly during the last sixteen years, they have been successfully applied in the chromatographic and electrophoretic analysis of value-added compounds extracted from biomass. Considering the growing interest in the use of ILs in this field, this critical review provides a comprehensive overview on the improvements achieved using ILs as constituents of mobile or stationary phases in analytical techniques, namely in capillary electrophoresis and its different modes, in high performance liquid chromatography, and in gas chromatography, for the separation and analysis of natural compounds. The impact of the IL chemical structure and the influence of secondary parameters, such as the IL concentration, temperature, pH, voltage and analysis time (when applied), are also critically addressed regarding the achieved separation improvements. Major conclusions on the role of ILs in the separation mechanisms and the performance of these techniques in terms of efficiency, resolution and selectivity are provided. Based on a critical analysis of all published results, some target-oriented ILs are suggested. Finally, current drawbacks and future challenges in the field are highlighted. In particular, the design and use of more benign and effective ILs as well as the development of integrated (and thus more sustainable) extraction-separation processes using IL aqueous solutions are suggested within a green chemistry perspective.

  8. Accuracy improvement of the ice flow rate measurements on Antarctic ice sheet by DInSAR method

    NASA Astrophysics Data System (ADS)

    Shiramizu, Kaoru; Doi, Koichiro; Aoyama, Yuichi

    2015-04-01

    to be apparent ones, the average could be a measure of flow rate estimation accuracy by DInSAR. Therefore, it is concluded that the accuracy of the ice flow rate measurement can be improved by using PRISM-DEM. In this presentation, we will show the results of the estimated flow rate of ice streams in the region of interest, and discuss the additional accuracy improvement of this method.

  9. Crude clove bud oil (CBO) quality improvement by bentonite adsorption process in flow system

    NASA Astrophysics Data System (ADS)

    Rubiyanto, Dwiarso; Diaty, Dita; Allwar

    2017-03-01

    Improvement of the quality of crude clove bud oil (crude CBO) by bentonite adsorption process in flow system had been done. This research aimed to improve the quality of crude CBO based on SNI 06-4267-1996 and SNI 06-2387-2006. The parameters were colours, densities, refractives index, eugenol and trans-caryophillene contents and also the additional analysis parameter which were the analysis of Fe using bentonite and measurement of pH using universal paper. Adsorption was carried out in the optimation of bentonite. The weight variations of bentonite was 5, 10, 15 and 20 grams. From the surface area analysis, it showed that bentonite had surface area about 30,512 m2/g which was activated chemically using 0,5 M HCl and calcinated using furnace in temperature of 400 0C. The results showed that the analysis of colours, densities, recfractives index and test of pH were not different significantly. Meanwhile the adsorption of Fe metal using 20 gram bentonite be able to adsorp until 94,20%. The highest percentage of eugenol found in the variation of 5 gram which was about 13,52% and decreased trans-caryophillene in 9,64% of 15 gram bentonite.

  10. Experimental study on improvement effect of guide wall to water flow in bend of spillway chute.

    PubMed

    Zhang, Qinghua; Diao, Yanfang; Zhai, Xingtao; Li, Shuning

    2016-01-01

    In order to improve water flow in a bend of a spillway chute using a guide wall, modeling experiments with or without a guide wall under conditions of three different bend axial radii, three chute bottom slopes and three flow rates were carried out in this study. Two indexes were calculated, which are the improved water surface uniformity and the reduced rate of water surface difference in concave and convex banks of the cross-section. The results show that: (1) setting a guide wall in a bend can improve water flow in the bend because it increased the water surface uniformity of the cross-section and reduced the water surface difference in the concave and convex banks; (2) the smaller the bend axial radius, the better the water surface improvement effect will be using a guide wall; (3) the steeper the bottom slope, the more cross-sections with less water surface difference; and (4) flow rates have a great influence on water surface improvement in the bend, and the guide wall can improve water flow obviously when the water depth in the starting section of the bend is lower than the height of the guide wall. This study has important implications in engineering design of guide walls.

  11. Response improvement of a mover device using hydrogen storage alloy powder by addition of catalyst

    NASA Astrophysics Data System (ADS)

    Sato, Akira; Akazawa, Kaoru; Ogasawara, Takashi; Uchida, Haru-Hisa; Nishi, Yoshitake

    2007-01-01

    Recently we proposed a mechanical mover device in a unimorph structure with powder hydrogen storage alloy dispersed. A silicone rubber sheet with the alloy was piled up on another pure silicone rubber sheet, then mechanical movement was generated by hydrogen gas absorption and desorption. Because the response of the movement was slow, therefore, in this research we tested the additive effect of catalyst of Pd-Al IIO 3 powder into the hydrogen storage alloy powder before mixing with rubber. The mover device with the catalyst indicated drastically modified responses, such as higher initial moving rate and also larger displacement. The results suggested the possibility of the device for medical purpose such as catheter because of a powerful but tender characteristic of the device.

  12. Multifunctional additives to improve the low-temperature properties of distillate fuels and compositions thereof

    SciTech Connect

    Baillargeon, D.J.; Cardis, A.B.; Heck, F.; Heck, D.B.

    1991-08-13

    This patent describes a fuel composition comprising a major proportion of a liquid hydrocarbyl fuel and a minor proportion. It comprises about 0.001 wt % to about 10 wt % based on the total weight of the composition of an additive product of reaction obtained by reacting in differing ratios a hydrocarbyl diol or mixture of hydrocarbyl diols and a reactive acid and/or anhydride derived from the reaction of pyromellitic dianhydride of its acid equivalent having hydrocarbyl groups derived from aminoalcohols, derived from secondary amines capped with an olefin oxide, having a combination of hydrocarbyl groups attached thereto and wherein the differing ratios are less than molar ratios, substantially molar ratios and more than molar ratios and; where the temperature of reaction varies from about 150{degrees} C to 200{degrees} C, at pressure of from about 0.001 atm to 1 atm.

  13. Color reproductivity improvement with additional virtual color filters for WRGB image sensor

    NASA Astrophysics Data System (ADS)

    Kawada, Shun; Kuroda, Rihito; Sugawa, Shigetoshi

    2013-02-01

    We have developed a high accuracy color reproduction method based on an estimated spectral reflectance of objects using additional virtual color filters for a wide dynamic range WRGB color filter CMOS image sensor. The four virtual color filters are created by multiplying the spectral sensitivity of White pixel by gauss functions which have different central wave length and standard deviation, and the virtual sensor outputs of those virtual filters are estimated from the four real output signals of the WRGB image sensor. The accuracy of color reproduction was evaluated with a Macbeth Color Checker (MCC), and the averaged value of the color difference ΔEab of 24 colors was 1.88 with our approach.

  14. Poly iron sulfate flocculant as an effective additive for improving the performance of microbial fuel cells.

    PubMed

    Miyahara, Morio; Sakamoto, Akihiro; Kouzuma, Atsushi; Watanabe, Kazuya

    2016-12-01

    Laboratory microbial fuel cells were supplied with artificial wastewater and used to examine how supplementation with poly iron sulfate, an inorganic polymer flocculant widely used in wastewater-treatment plants, affects electricity generation and anode microbiomes. It is shown that poly iron sulfate substantially increases electric outputs from microbial fuel cells. Microbiological analyses show that iron and sulfate separately affect anode microbiomes, and the increase in power output is associated with the increases in bacteria affiliated with the families Geobacteraceae and/or Desulfuromonadaceae. We suggest that poly iron sulfate is an effective additive for increasing the electric output from microbial fuel cells. Other utilities of poly iron sulfate in microbial fuel cells are also discussed.

  15. Addition of Selenium Nanoparticles to Electrospun Silk Scaffold Improves the Mammalian Cell Activity While Reducing Bacterial Growth

    PubMed Central

    Chung, Stanley; Ercan, Batur; Roy, Amit K.; Webster, Thomas J.

    2016-01-01

    Silk possesses many beneficial wound healing properties, and electrospun scaffolds are especially applicable for skin applications, due to their smaller interstices and higher surface areas. However, purified silk promotes microbial growth. Selenium nanoparticles have shown excellent antibacterial properties and are a novel antimicrobial chemistry. Here, electrospun silk scaffolds were doped with selenium nanoparticles to impart antibacterial properties to the silk scaffolds. Results showed significantly improved bacterial inhibition and mild improvement in human dermal fibroblast metabolic activity. These results suggest that the addition of selenium nanoparticles to electrospun silk is a promising approach to improve wound healing with reduced infection, without relying on antibiotics. PMID:27471473

  16. Buffer additives, Mg-lime improve SO/sub 2/ scrubber performance

    SciTech Connect

    Smock, R.

    1982-08-01

    Demonstrations indicate that adipic acid and other organic buffering agents can improve the performance of limestone scrubbers for utilities using high-sulfur coal. Organic buffers used during the nine-month demonstration boosted the efficiency of sulfur dioxide (SO/sub 2/) removal from 70% to 95%. Despite legal incentives, the results are consistent with other industrial-scale and pilot-plant tests. Dibasic acids (DBA) had similar results. The low cost of buffer enhancing makes it a low-risk investment for utilities that need to bring their scrubbers into compliance with environmental standards. Scrubbers using adipic acid reduce capital costs 10% below conventional designs and annual operating costs 11%. 1 figure, 6 tables. (DCK)

  17. Improved performance of U-Mo dispersion fuel by Si addition in Al matrix.

    SciTech Connect

    Kim, Y S; Hofman, G L

    2011-06-01

    The purpose of this report is to collect in one publication and fit together work fragments presented in many conferences in the multi-year time span starting 2002 to the present dealing with the problem of large pore formation in U-Mo/Al dispersion fuel plates first observed in 2002. Hence, this report summarizes the excerpts from papers and reports on how we interpreted the relevant results from out-of-pile and in-pile tests and how this problem was dealt with. This report also provides a refined view to explain in detail and in a quantitative manner the underlying mechanism of the role of silicon in improving the irradiation performance of U-Mo/Al.

  18. Improvements and Additions to NASA Near Real-Time Earth Imagery

    NASA Technical Reports Server (NTRS)

    Cechini, Matthew; Boller, Ryan; Baynes, Kathleen; Schmaltz, Jeffrey; DeLuca, Alexandar; King, Jerome; Thompson, Charles; Roberts, Joe; Rodriguez, Joshua; Gunnoe, Taylor; Wong, Minnie; Alarcon, Christian; DeCesare, Cristina; Pressley, Natalie

    2016-01-01

    For many years, the NASA Global Imagery Browse Services (GIBS) has worked closely with the Land, Atmosphere Near real-time Capability for EOS (Earth Observing System) (LANCE) system to provide near real-time imagery visualizations of AIRS (Atmospheric Infrared Sounder), MLS (Microwave Limb Sounder), MODIS (Moderate Resolution Imaging Spectrometer), OMI (Ozone Monitoring Instrument), and recently VIIRS (Visible Infrared Imaging Radiometer Suite) science parameters. These visualizations are readily available through standard web services and the NASA Worldview client. Access to near real-time imagery provides a critical capability to GIBS and Worldview users. GIBS continues to focus on improving its commitment to providing near real-time imagery for end-user applications. The focus of this presentation will be the following completed or planned GIBS system and imagery enhancements relating to near real-time imagery visualization.

  19. Iron bioavailability in corn-masa tortillas is improved by the addition of disodium EDTA.

    PubMed

    Walter, Tomás; Pizarro, Fernando; Olivares, Manuel

    2003-10-01

    Corn-masa flour flat bread tortillas are the main staple of Mexican and Central American populations. Due to high concentrations of inhibitors of iron absorption, the bioavailability from this matrix is unknown. We wanted to determine the most suitable fortificant that would efficaciously improve iron bioavailability. In tortillas prepared with commercial precooked, lime-treated, corn-masa flour, we examined the in vitro solubility of the following forms of iron: native iron with and without Na2EDTA, elemental reduced iron plus Na2EDTA, ferrous fumarate with and without Na2EDTA, bisglycine iron, ferrous sulfate and NaFeEDTA. We also examined the in vivo bioavailability in humans with double radioiron erythrocyte incorporation of ferrous fumarate with and without Na2EDTA, bisglycine iron, NaFeEDTA and native iron plus Na2EDTA, beans and rice. In vitro, solubility ranged from 1% in iron forms without Na2EDTA to 19.4% for NaFeEDTA. Forms of iron with Na2EDTA had intermediate values. In vivo radioiron studies showed that iron forms without Na2EDTA also had low bioavailability (< or =1%). NaFeEDTA had the highest bioavailability (5.3%). The bioavailability of all iron forms improved significantly when tested with Na2EDTA (<0.05). Adding Na2EDTA to ferrous fumarate increased bioavailability from 0.87% to 2.9% (P < 0.001). We conclude that NaFeEDTA is the form of iron best absorbed, but alternatively, ferrous fumarate plus Na2EDTA comprises a feasible option as a fortificant.

  20. Sub-piexl methods for improving vector quality in echo PIV flow, imaging technology.

    PubMed

    Niu, Lili; Wang, Jing; Qian, Ming; Zheng, Hairong

    2009-01-01

    Developments of many cardiovascular problems have been shown to have a close relationship with arterial flow conditions. An ultrasound-based particle image velocimetry technique(Echo PIV) was recently developed to measure multi-component velocity vectors and local shear rates in arteries and opaque fluid flows by identifying and tracking flow tracers (ultrasound contrast microbubbles) within these flow fields. To improve the measurement accuracy, sub-pixel calculation method was adopted in this paper to maximize the ultrasound RF signal and B mode image correlation accuracy and increase the image spatial resolution. This algorithm is employed in processing both computer-generated particle image patterns and the B-mode images of microbubbles in rotating flows obtained by a high frame rate (up to 1000 frames per second) ultrasound imaging system. The results show the correlation of particle patterns and individual flow vector quality are improved and the overall flow mappings are also improved significantly. This would help the Echo PIV system to provide better multi-component velocity accuracy.

  1. Engineered particles demonstrate improved flow properties at elevated drug loadings for direct compression manufacturing.

    PubMed

    Trementozzi, Andrea N; Leung, Cheuk-Yui; Osei-Yeboah, Frederick; Irdam, Erwin; Lin, Yiqing; MacPhee, J Michael; Boulas, Pierre; Karki, Shyam B; Zawaneh, Peter N

    2017-03-08

    Optimizing powder flow and compaction properties are critical for ensuring a robust tablet manufacturing process. The impact of flow and compaction properties of the active pharmaceutical ingredient (API) becomes progressively significant for higher drug load formulations, and for scaling up manufacturing processes. This study demonstrated that flow properties of a powder blend can be improved through API particle engineering, without critically impacting blend tabletability at elevated drug loadings. In studying a jet milled API (D50=24μm) and particle engineered wet milled API (D50=70μm and 90μm), flow functions of all API lots were similarly poor despite the vast difference in average particle size (ffc<4). This finding strays from the common notion that powder flow properties are directly correlated to particle size distribution. Upon adding excipients, however, clear trends in flow functions based on API particle size were observed. Wet milled API blends had a much improved flow function (ffc>10) compared with the jet milled API blends. Investigation of the compaction properties of both wet and jet milled powder blends also revealed that both jet and wet milled material produced robust tablets at the drug loadings used. The ability to practically demonstrate this uncommon observation that similarly poor flowing APIs can lead to a marked difference upon blending is important for pharmaceutical development. It is especially important in early phase development during API selection, and is advantageous particularly when material-sparing techniques are utilized.

  2. A Discounted Cash Flow variant to detect the optimal amount of additional burdens in Public-Private Partnership transactions.

    PubMed

    Copiello, Sergio

    2016-01-01

    The Discounted Cash Flow method is a long since well-known tool to assess the feasibility of investment projects, as the background which shapes a broad range of techniques, from the Cost-Benefit Analysis up to the Life-Cycle Cost Analysis. Its rationale lies in the comparison of deferred values, only once they have been discounted back to the present. The DCF variant proposed here fits into a specific application field. It is well-suited to the evaluations required in order to structure equitable transactions under the umbrella of Public-Private Partnership. •The discount rate relies upon the concept of expected return on equity, instead than on those of weighted average cost of capital, although the latter is the most common reference within the scope of real estate investment valuation.•Given a feasible project, whose Net Present Value is more than satisfactory, we aim to identify the amount of the additional burdens that could be charged to the project, under the condition of keeping the same economically viable.•The DCF variant essentially deals with an optimization problem, which can be solved by means of simple one-shot equations, derived from financial mathematics, or through iterative calculations if additional constraints must be considered.

  3. Improving the predictive accuracy of hurricane power outage forecasts using generalized additive models.

    PubMed

    Han, Seung-Ryong; Guikema, Seth D; Quiring, Steven M

    2009-10-01

    Electric power is a critical infrastructure service after hurricanes, and rapid restoration of electric power is important in order to minimize losses in the impacted areas. However, rapid restoration of electric power after a hurricane depends on obtaining the necessary resources, primarily repair crews and materials, before the hurricane makes landfall and then appropriately deploying these resources as soon as possible after the hurricane. This, in turn, depends on having sound estimates of both the overall severity of the storm and the relative risk of power outages in different areas. Past studies have developed statistical, regression-based approaches for estimating the number of power outages in advance of an approaching hurricane. However, these approaches have either not been applicable for future events or have had lower predictive accuracy than desired. This article shows that a different type of regression model, a generalized additive model (GAM), can outperform the types of models used previously. This is done by developing and validating a GAM based on power outage data during past hurricanes in the Gulf Coast region and comparing the results from this model to the previously used generalized linear models.

  4. Natural and synthetic antioxidant additives for improving the performance of new biolubricant formulations.

    PubMed

    Quinchia, Lida A; Delgado, Miguel A; Valencia, Concepción; Franco, José M; Gallegos, Crispulo

    2011-12-28

    Knowledge of the oxidative stability of vegetable oils for lubricant applications is a key point, because vegetable oil oxidation potential is the main disadvantage for its use as a lubricant. Oil degradation after an oxidation process can seriously affect its lubricating function and increase wear. In this work, two different methods for evaluating the oxidation stability of lubricating vegetable oils, the oxidation onset temperature, characterized through DSC measurements (ASTM E 2009-08), and the pressure drop in the oxygen pressure vessel (ASTM D 942-02), have been used. Additionally, thermogravimetric analysis and FTIR studies have also been carried out. High-oleic sunflower (HOSO) and castor (CO) oils were selected and blended with natural ((+)-α-tocopherol (TCP), propyl gallate (PG), l-ascorbic acid 6-palmitate (AP)) or synthetic antioxidants (4,4'-methylenebis(2,6-di-tert-butylphenol) (MBP)), with the aim of formulating biodegradable vegetable-based lubricants according to REACH regulation. (1) The results showed that the most effective biodegradable antioxidant is PG, comparable to MBP, whereas lower effectiveness was obtained for TCP and AP. In relation to the methods tested, DSC measurements achieve accurate data more quickly for evaluating the oxidation stability of these basestocks, showing a linear correlation with the traditional method based on the oxygen bomb test. The empirical equation obtained depends on the mechanism involved in the antioxidant activity.

  5. Using porphyritic andesite as a new additive for improving hydrolysis and acidogenesis of solid organic wastes.

    PubMed

    Li, Dawei; Zhou, Tao; Chen, Ling; Jiang, Weizhong; Cheng, Fan; Li, Baoming; Kitamura, Yutaka

    2009-12-01

    The effects of porphyritic andesite on the hydrolysis and acidogenesis of solid organic wastes were investigated by batch and continuous experiments using a rotational drum fermentation system. The results of the batch experiment show that if porphyritic andesite (1%, 3%, and 5% reactants) is added initially, the pH level increases and hydrolysis and acidogenesis are accelerated. The highest surface based hydrolysis constant (26.4x10(-3) kgm(-2) d(-1)) and volatile solid degradation ratio (43.3%) were obtained at a 1% porphyritic andesite addition. In the continuous experiment, porphyritic andesite elevated the first order hydrolysis constant from 13.10x10(-3) d(-1) to 18.82x10(-3) d(-1). A particle mean diameter reduction rate of 33.05 microm/d and a volatile solid degradation rate of 3.53 g/L d(-1) were obtained under the hydraulic retention time of 4, 8, 12 and 16 d.

  6. Improvements in nanoscale zero-valent iron production by milling through the addition of alumina

    NASA Astrophysics Data System (ADS)

    Ribas, D.; Cernik, M.; Martí, V.; Benito, J. A.

    2016-07-01

    A new milling procedure for a cost-effective production of nanoscale zero-valent iron for environmental remediation is presented. Conventional ball milling of iron in an organic solvent as Mono Ethylene Glycol produces flattened iron particles that are unlikely to break even after very long milling times. With the aim of breaking down these iron flakes, in this new procedure, further milling is carried out by adding an amount of fine alumina powder to the previously milled solution. As the amount of added alumina increases from 9 to 54 g l-1, a progressive decrease of the presence of flakes is observed. In the latter case, the appearance of the particles formed by fragments of former flakes is rather homogeneous, with most of the final nanoparticles having an equivalent diameter well below 1 µm and with an average particle size in solution of around 400 nm. An additional increase of alumina content results in a highly viscous solution showing worse particle size distribution. Milled particles, in the case of alumina concentrations of 54 g l-1, have a fairly large specific surface area and high Fe(0) content. These new particles show a very good Cr(VI) removal efficiency compared with other commercial products available. This good reactivity is related to the absence of an oxide layer, the large amount of superficial irregularities generated by the repetitive fracture process during milling and the presence of a fine nanostructure within the iron nanoparticles.

  7. Improvement of dairy manufacture effluent anaerobic digestion with biological waste addition using a Chinese dome digester.

    PubMed

    Jihen, Toumi; Hassib, Bouallagui; Moktar, Hamdi; Said, Nouira

    2010-05-01

    Anaerobic co-digestion of dairy manufacture effluent (DME) and biological waste (BW) was investigated at various DME/BW ratios using laboratory batch digesters. The biogas yield ranged 0.34-0.88l biogas g(-1) volatile solids (VS) removed. The highest VS reductions of 58% and 62% were obtained for DME/BW ratios of 60:40% and 80:20%, respectively. Results were used to operate a pilot-scale digester of 5m(3). The highest biogas yield of 0.48lg(-1) VS removed was obtained at an organic loading rate (OLR) of 1.64gVSl(-1)d(-1) corresponding to a DME/BW ratio of 80:20%. This could be mainly attributed to the higher biodegradability of DME and the correction of the C:N ratio by the addition of the BW. The N, P and K contents were increased significantly in the TS of the digestate to be around 6.8%, 0.64% and 1.26%, respectively.

  8. Addition of cattle manure to sheep bedding allows vermicomposting process and improves vermicompost quality.

    PubMed

    Cestonaro, Taiana; Costa, Mônica Sarolli Silva de Mendonça; Costa, Luiz Antonio de Mendonça; Pereira, Dercio Ceri; Rozatti, Marcos A T; Martins, Marcos F Leal

    2017-03-01

    Animal waste is usually a good substrate for vermicomposting. However, numerous animal husbandry systems use bedding that consists primarily of lignocellulosic substrates, which hinders earthworm and microorganism's development and thus, the entire bioconversion process. One possible solution is to mix the used bedding with other waste materials that are more amenable to earthworm ingestion and can provide better conditions for earthworm population growth. Here, we have aimed to examine the effectiveness of such procedure by mixing rice-husk-based sheep bedding with cattle manure in different proportions (0%, 25%, 50%, 75% and 100%). We have carried out vermicomposting experiments in benchtop vermireactors inoculated with 0.88kg of dry matter (sheep bedding+cattle manure). Data used in the Principal Component Analysis were the multiple vermicomposting variables (i.e., EC; pH; HA/FA and C/N ratios; P, K, cellulose, and hemicellulose content). The effect of the treatment on earthworm count was analyzed with ANOVA. We have observed that the addition of at least 25% of cattle manure to sheep bedding allows vermicomposting process but it is necessary 148days to obtain a stabilized vermicompost. However, increasing the proportion of cattle manure to sheep bedding, the vermicomposting time decreases proportionally to 94days. We concluded that vermicomposting can be considered a bioprocess to stabilize rice husk after being used as sheep bedding.

  9. Improved stability of chokeberry juice anthocyanins by β-cyclodextrin addition and refrigeration.

    PubMed

    Howard, Luke R; Brownmiller, Cindi; Prior, Ronald L; Mauromoustakos, Andy

    2013-01-23

    Chokeberry anthocyanins are susceptible to degradation during processing and storage of processed products. This study determined the effects of three pH levels (2.8, 3.2, and 3.6) and four β-cyclodextrin (BCD) concentrations (0, 0.5, 1, and 3%) alone and in combination on the stability of chokeberry juice anthocyanins before and after pasteurization and over 8 months of storage at 4 and 25 °C. Lowering the pH from 3.6 to 2.8 in the absence of BCD provided marginal protection against anthocyanin losses during processing and storage. Addition of 3% BCD at the natural chokeberry pH of 3.6 resulted in excellent protection of anthocyanins, with 81 and 95% retentions after 8 months of storage at 25 and 4 °C, respectively. The protective effect of BCD was lessened with concentrations <3% and reduction in pH, indicating changes in anthocyanin structure play an important role in BCD stabilization of anthocyanins.

  10. Effect of water quality improvement on the remediation of river sediment due to the addition of calcium nitrate.

    PubMed

    Liu, Xiaoning; Tao, Yi; Zhou, Kuiyu; Zhang, Qiqi; Chen, Guangyao; Zhang, Xihui

    2017-01-01

    In situ sediment remediation technique is commonly used to control the release of pollutants from sediment. Addition of calcium nitrate to sediment has been applied to control the release of phosphorus from sediments. In this study, laboratory experiments were conducted to investigate the effect of water quality improvement on the remediation of river sediment with the addition of calcium nitrate. The results demonstrated that the redox-potential of sediments increased from -282mV to -130mV after 28days of calcium nitrate treatment. The acid volatile sulphide in the sediments significantly decreased (by 54.9% to 57.1%), whereas the total organic carbon decreased by 9.7% to 10.2%. However, the difference between these and water quality improvement was not significant. Due to the addition of calcium nitrate, low phosphate concentration in the water column and interstitial phosphate in the sediment were observed, indicating that the calcium nitrate was beneficial to controlling the release of phosphorus from river sediment. The decrease in phosphorus release could be attributed to the fixation of iron-phosphorus and calcium-phosphorus due to the addition of calcium nitrate. The addition of calcium nitrate to sediment caused the oxidation of sulphide to sulphate, hence resulting in high nitrate and sulphate concentrations in the water column, and high interstitial nitrate and sulphate concentrations in the sediment. The results also showed that only the water quality improvement had a significant effect on the interstitial nitrate and sulphate concentrations in the sediment.

  11. Reevaluation of Tetrahydrophthalic Anhydride as an End Cap for Improved Oxidation Resistance in Addition Polyimides

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.; Frimer, Aryeh A.; Johnston, J. Christopher

    2003-01-01

    Several substituted 1,2,3,6-tetrahydrophthalic anhydride end caps - including the 3-phenyl, 3-methoxy, 3-trimethylsilyloxy, and 3,6-diphenyl analogs - were synthesized via the Diels-Alder condensation of the corresponding butadienes and maleic anhydride. These anhydrides, as well as the commercially available 3-hydro and 4-methyl analogs, were each ground together with methylenedianiline in a 2:1 ratio and heated gradually from 204 C to 371 C, with the thermolysis followed by NMR. Generally speaking, a transformation via monoimide to bisimide was observed in the lower temperature range, followed by competition between crosslinking and aromatization. We believe that this competition produces a substantial percentage of aromatic product, with the concomitant lowering of the relative amount of crosslinking and is responsible for improving both thermal oxidative stability of tetrahydrophthalic end capped polyimides and their substantial frangibility. The thermolysis of the tetrahydrophthalimides under inert atmosphere dramatically lowers the amount of aromatization hence, the mechanism for aromatization is an oxidative one.

  12. Improvement of mesophilic anaerobic co-digestion of agri-food waste by addition of glycerol.

    PubMed

    Serrano, Antonio; Siles, Jose A; Chica, Arturo F; Martin, M Angeles

    2014-07-01

    Anaerobic co-digestion is a promising alternative to manage agri-food waste rather than landfilling, composting or incineration. But improvement of methane yield and biodegradability is often required to optimize its economic viability. Biomethanization of agri-food solid waste presents the disadvantage of a slow hydrolytic phase, which might be enhanced by adding a readily digestible substrate such as glycerol. In this study, strawberry extrudate, fish waste and crude glycerol derived from biodiesel manufacturing are mixed at a proportion of 54:5:41, in VS (VS, total volatile solids), respectively. The mesophilic anaerobic co-digestion at lab-scale of the mixture was stable at loads lower than 1.85 g VS/L, reaching a methane yield coefficient of 308 L CH4/kg VS (0 °C, 1 atm) and a biodegradability of 96.7%, in VS. Moreover, the treatment capacity of strawberry and fish waste was increased 16% at adding the crude glycerol. An economic assessment was also carried out in order to evaluate the applicability of the proposed process. Even in a pessimistic scenario, the net balance was found to be positive. The glycerol adding implied a net saving in a range from 25.5 to 42.1 €/t if compared to landfill disposal.

  13. Associating cooking additives with sodium hydroxide to pretreat bamboo residues for improving the enzymatic saccharification and monosaccharides production.

    PubMed

    Huang, Caoxing; He, Juan; Wang, Yan; Min, Douyong; Yong, Qiang

    2015-10-01

    Cooking additive pulping technique is used in kraft mill to increase delignification degree and pulp yield. In this work, cooking additives were firstly applied in the sodium hydroxide pretreatment for improving the bioconversion of bamboo residues to monosaccharides. Meanwhile, steam explosion and sulfuric acid pretreatments were also carried out on the sample to compare their impacts on monosaccharides production. Results indicated that associating anthraquinone with sodium hydroxide pretreatment showed the best performance in improving the original carbohydrates recovery, delignification, enzymatic saccharification, and monosaccharides production. After consecutive pretreatment and enzymatic saccharification process, 347.49 g, 307.48 g, 142.93 g, and 87.15 g of monosaccharides were released from 1000 g dry bamboo residues pretreated by sodium hydroxide associating with anthraquinone, sodium hydroxide, steam explosion and sulfuric acid, respectively. The results suggested that associating cooking additive with sodium hydroxide is an effective pretreatment for bamboo residues to enhance enzymatic saccharification for monosaccharides production.

  14. Improving the quality of polymer-coated urea with recycled plastic, proper additives, and large tablets.

    PubMed

    Yang, Yue-Chao; Zhang, Min; Li, Yuncong; Fan, Xiao-Hui; Geng, Yu-Qing

    2012-11-14

    Polymer-coated urea (PCU) has great potential for increasing crop production and enhancing nitrogen (N) fertilizer use efficiency, benefiting the ecosystem. However, current PCUs are used only in a limited market, and the main obstacle to the wider use of PCUs is high cost compared to that of conventional N fertilizers. In this study, the low cost PCU and large tablet polymer-coated urea (LTPCU) were prepared by using recycling polystyrene foam and various sealants as the coating materials. The structural and chemical characteristics of the coating shells of the coated fertilizers were examined. The N release characteristics of coated fertilizers were determined in 25 °C water under laboratory conditions. The relationship between the N release longevity and the amount of coating material and the percentage of different sealants were evaluated. The results indicated that recycling polystyrene foam was the ideal coating material of the controlled release fertilizer. The polyurethane that was synthesized by the reaction of castor oil and isocyanate was better than the wax as the additive to delay the N release rate of coated urea. The coating material used for LTPCU was 70-80% less than those used for commercial PCUs under the same N release longevity. The cost of the recycling polystyrene foam used for coating one ton of pure N of the LTPCU was about one-seventh to one-eighth of the cost of the traditional polymer used for the commercial PCU. The experimental data showed that the LTPCU with good controlled-release capacities, being economical and eco-friendly, could be promising for wide use in agriculture and horticulture.

  15. Addition of a Gastrointestinal Microbiome Modulator to Metformin Improves Metformin Tolerance and Fasting Glucose Levels

    PubMed Central

    Burton, Jeffrey H.; Johnson, Matthew; Johnson, Jolene; Hsia, Daniel S.; Greenway, Frank L.; Heiman, Mark L.

    2015-01-01

    Background: Adverse effects of metformin are primarily related to gastrointestinal (GI) intolerance that could limit titration to an efficacious dose or cause discontinuation of the medication. Because some metformin side effects may be attributable to shifts in the GI microbiome, we tested whether a GI microbiome modulator (GIMM) used in combination with metformin would ameliorate the GI symptoms. Methods: A 2-period crossover study design was used with 2 treatment sequences, either placebo in period 1 followed by GIMM in period 2 or vice versa. Study periods lasted for 2 weeks, with a 2-week washout period between. During the first week, type 2 diabetes patients (T2D) who experienced metformin GI intolerance took 500 mg metformin along with their assigned NM504 (GIMM) or placebo treatment with breakfast and with dinner. In the second week, the 10 subjects took 500 mg metformin (t.i.d.), with GIMM or placebo consumed with the first and third daily metformin doses. Subjects were permitted to discontinue metformin dosing if it became intolerable. Results: The combination of metformin and GIMM treatment produced a significantly better tolerance score to metformin than the placebo combination (6.78 ± 0.65 [mean ± SEM] versus 4.45 ± 0.69, P = .0006). Mean fasting glucose levels were significantly (P < .02) lower with the metformin–GIMM combination (121.3 ± 7.8 mg/dl) than with metformin-placebo (151.9 ± 7.8 mg/dl). Conclusion: Combining a GI microbiome modulator with metformin might allow the greater use of metformin in T2D patients and improve treatment of the disease. PMID:25802471

  16. Improvements in sparse matrix/vector technique applications for on-line load flow calculation

    SciTech Connect

    Ristanovic, P.; Bjelogrlic, M.; Babic, B.S.

    1989-02-01

    Sparsity technique is applied to a wide range of problems in power systems analysis. In this paper the authors propose several analytical and computational improvements in sparsity applications. The new partial matrix refactorization method and ordering algorithm are presented. The proposed method is very efficient when applied to various kinds of programs, such as: on-line load flow, optimal power flow and steady-state security analysis. The proposed methodology is applied in a fast decoupled load flow program which include the treatment of tap violations on under-load tap changing (ULTC) transformers and reactive power generation on PV buses. Effects of proposed improvements are well tested and documented on the three networks: 118 bus IEEE test network and two utility networks with 209 and 519 buses, respectively. Keywords: sparsity technique, load flow analysis, security analysis.

  17. Improved Modeling of Naturally Fractured Reservoirs by Quantitatively Handling Flow Convergence into the Wellbore

    NASA Astrophysics Data System (ADS)

    Stadelman, M.; Crandall, D.; Sams, W. N.; Bromhal, G. S.

    2015-12-01

    Complex fractured networks in the subsurface control the flow of fluids in many applications, and accurately modeling their interaction with wells is critical to understanding their behavior. For tight sand and shale formations, fluid flow is primarily restricted to fractures within each rock layer. NFFLOW was designed by the Department of Energy to model gas well production from naturally fractured reservoirs. NFFLOW is a discrete fracture simulator, with every fracture and rock matrix in the domain handled individually. One-dimensional models are used calculate the flow through connected fractures and flow from the surrounding rocks into fractures. Flow into wellbores are determined from the combined flux from connecting fractures and adjacent rock matrices. One-dimensional fluid flow equations are used because they are extremely fast to solve and represent a reasonable approximation of the physical behavior of fluids in most of the reservoir. However, near the wellbore those models become inaccurate due to gas flow convergence, which is a multidimensional situation. We present a method to correct the one-dimensional models, using data from two-dimensional fluid flow models, while maintaining the original simulator speed. By applying corrections from the two-dimensional model, the one-dimensional models can better account for gas flow convergence into the wellbore as well as the location of the wellbore within the rock strata. Corrections were successful in scaling the one-dimensional flow rates to match the two dimensional values over a wide range of parameters for both fracture flow and porous media flow into the wellbore. This is shown to increase the accuracy of history matching to production data for a wide range of wells, allowing for better modeling and prediction of future productivity. With an accurate history match established, NFFLOW can then be used to investigate issues such as the ability of the formation to sequester carbon dioxide or the effects

  18. Improved prediction of disturbed flow via hemodynamically-inspired geometric variables.

    PubMed

    Bijari, Payam B; Antiga, Luca; Gallo, Diego; Wasserman, Bruce A; Steinman, David A

    2012-06-01

    Arterial geometry has long been considered as a pragmatic alternative for inferring arterial flow disturbances, and their impact on the natural history and treatment of vascular diseases. Traditionally, definition of geometric variables is based on convenient shape descriptors, with only superficial consideration of their influence on flow and wall shear stress patterns. In the present study we demonstrate that a more studied consideration of the actual (cf. nominal) local hemodynamics can lead to substantial improvements in the prediction of disturbed flow by geometry. Starting from a well-characterized computational fluid dynamics (CFD) dataset of 50 normal carotid bifurcations, we observed that disturbed flow tended to be confined proximal to the flow divider, whereas geometric variables previously shown to be significant predictors of disturbed flow included features distal to the flow divider in their definitions. Flaring of the bifurcation leading to flow separation was redefined as the maximum relative expansion of the common carotid artery (CCA), proximal to the flow divider. The beneficial effect of primary curvature on flow inertia, via suppression of flow separation, was characterized by the in-plane tortuosity of CCA as it enters the flare region. Multiple linear regressions of these redefined geometric variables against various metrics of disturbed flow revealed R(2) values approaching 0.6, better than the roughly 0.3 achieved using the conventional shape-based variables, while maintaining their demonstrated real-world reproducibility. Such a hemodynamically-inspired approach to the definition of geometric variables may reap benefits for other applications where geometry is used as a surrogate marker of local hemodynamics.

  19. Improved radiation dose efficiency in solution SAXS using a sheath flow sample environment

    PubMed Central

    Kirby, Nigel; Cowieson, Nathan; Hawley, Adrian M.; Mudie, Stephen T.; McGillivray, Duncan J.; Kusel, Michael; Samardzic-Boban, Vesna; Ryan, Timothy M.

    2016-01-01

    Radiation damage is a major limitation to synchrotron small-angle X-ray scattering analysis of biomacromolecules. Flowing the sample during exposure helps to reduce the problem, but its effectiveness in the laminar-flow regime is limited by slow flow velocity at the walls of sample cells. To overcome this limitation, the coflow method was developed, where the sample flows through the centre of its cell surrounded by a flow of matched buffer. The method permits an order-of-magnitude increase of X-ray incident flux before sample damage, improves measurement statistics and maintains low sample concentration limits. The method also efficiently handles sample volumes of a few microlitres, can increase sample throughput, is intrinsically resistant to capillary fouling by sample and is suited to static samples and size-exclusion chromatography applications. The method unlocks further potential of third-generation synchrotron beamlines to facilitate new and challenging applications in solution scattering. PMID:27917826

  20. Enhancement of critical heat flux in subcooled flow boiling of water by use of a volatile additive

    SciTech Connect

    Pabisz, R.A. Jr.; Bergles, A.E.

    1996-12-31

    The present investigation considers the effect of a 1-pentanol additive in water on the critical heat flux (CHF) and pressure drop in forced subcooled boiling. A small quantity of 1-pentanol was added to distilled water with the objective of getting an approximate 2% by weight mixture, which had been found to give superior performance in previous studies of pool and flow boiling. Experiments were performed using stainless steel tubes with internal diameters of 4.4 and 6.1 mm. Tests were conducted with mass fluxes of 4,400 kg/m{sup 2}s, exit pressures of 9 bar, length-to-diameter ratios of 25, and exit subcoolings from 65 to 90 C. Test sections were heated directly by DC power, and critical heat flux data were inferred from test-section burnout. The alcohol concentration was periodically checked by draining off a sample and performing a Proton Nuclear Magnetic Resonance scan on the mixture. At high subcoolings, the mixture exhibited an increase in the critical heat flux over that of pure water. However at low subcoolings there is a decrease in the critical heat flux. The increases in critical heat flux noted with the 1-pentanol mixture in this experiment were not as large as would be expected from saturated pool boiling results published by Van Stralen (1959). Pressure drop data for both the mixture and the pure water also were recorded. The 1-pentanol mixture, in general, exhibited larger pressure drops for the same conditions. Subcooled flow boiling has a wide array of commercial cooling applications, including blades in gas turbines, high power laser optics, plasma-facing components in fusion reactors, supercomputers, etc.

  1. Additions to compact heat exchanger technology: Jet impingement cooling & flow & heat transfer in metal foam-fins

    NASA Astrophysics Data System (ADS)

    Onstad, Andrew J.

    Compact heat exchangers have been designed following the same basic methodology for over fifty years. However, with the present emphasis on energy efficiency and light weight of prime movers there is increasing demand for completely new heat exchangers. Moreover, new materials and mesoscale fabrication technologies offer the possibility of significantly improving heat exchanger performance over conventional designs. This work involves fundamental flow and heat transfer experimentation to explore two new heat exchange systems: in Part I, large arrays of impinging jets with local extraction and in Part II, metal foams used as fins. Jet impingement cooling is widely used in applications ranging from paper manufacturing to the cooling of gas turbine blades because of the very high local heat transfer coefficients that are possible. While the use of single jet impingement results in non-uniform cooling, increased and more uniform mean heat transfer coefficients may be attained by dividing the total cooling flow among an array of smaller jets. Unfortunately, when the spent fluid from the array's central jets interact with the outer jets, the overall mean heat transfer coefficient is reduced. This problem can be alleviated by locally extracting the spent fluid before it is able to interact with the surrounding jets. An experimental investigation was carried out on a compact impingement array (Xn/Djet = 2.34) utilizing local extraction of the spent fluid (Aspent/Ajet = 2.23) from the jet exit plane. Spatially resolved measurements of the mean velocity field within the array were carried out at jet Reynolds numbers of 2300 and 5300 by magnetic resonance velocimetry, MRV. The geometry provided for a smooth transition from the jet to the target surface and out through the extraction holes without obvious flow recirculation. Mean Nusselt number measurements were also carried out for a Reynolds number range of 2000 to 10,000. The Nusselt number was found to increase with the

  2. Modification and Improvement of Software for Modeling Multidimensional Reacting Fuel Flows

    DTIC Science & Technology

    1989-07-01

    aQ IC FILE COPY WRDC-TR-89-2056 MODIFICATION AND IMPROVEMENT OF SOFTWARE FOR MODELING MULTIDIMENSIONAL REACTING FUEL FLOWS Dr. David E. Keyes Mr...Modeling Multidimensional Reacting Fuel Flows 12. PERSONAL AUITHOR(S Dr. David Keyes , Mr. Dennis Philbin, Dr. Mitchell Smoke I I& TYPt Of IMPORT 113b. TIME...al. [15], and Keyes and Smooke [16)). We assume that the fuel and the oxidizer obey a single overall irreversible reaction of the type Fuel (F

  3. Using Discrete Event Computer Simulation to Improve Patient Flow in a Ghanaian Acute Care Hospital

    PubMed Central

    Best, Allyson M.; Dixon, Cinnamon A.; Kelton, W. David; Lindsell, Christopher J.

    2014-01-01

    Objectives Crowding and limited resources have increased the strain on acute care facilities and emergency departments (EDs) worldwide. These problems are particularly prevalent in developing countries. Discrete event simulation (DES) is a computer-based tool that can be used to estimate how changes to complex healthcare delivery systems, such as EDs, will affect operational performance. Using this modality, our objective was to identify operational interventions that could potentially improve patient throughput of one acute care setting in a developing country. Methods We developed a simulation model of acute care at a district level hospital in Ghana to test the effects of resource-neutral (e.g. modified staff start times and roles) and resource-additional (e.g. increased staff) operational interventions on patient throughput. Previously captured, de-identified time-and-motion data from 487 acute care patients were used to develop and test the model. The primary outcome was the modeled effect of interventions on patient length of stay (LOS). Results The base-case (no change) scenario had a mean LOS of 292 minutes (95% CI 291, 293). In isolation, neither adding staffing, changing staff roles, nor varying shift times affected overall patient LOS. Specifically, adding two registration workers, history takers, and physicians resulted in a 23.8 (95% CI 22.3, 25.3) minute LOS decrease. However, when shift start-times were coordinated with patient arrival patterns, potential mean LOS was decreased by 96 minutes (95% CI 94, 98); and with the simultaneous combination of staff roles (Registration and History-taking) there was an overall mean LOS reduction of 152 minutes (95% CI 150, 154). Conclusions Resource-neutral interventions identified through DES modeling have the potential to improve acute care throughput in this Ghanaian municipal hospital. DES offers another approach to identifying potentially effective interventions to improve patient flow in emergency and acute

  4. Improving the performance of an aerobic membrane bioreactor (MBR) treating pharmaceutical wastewater with powdered activated carbon (PAC) addition.

    PubMed

    Kaya, Yasemin; Bacaksiz, A Murat; Golebatmaz, Ugur; Vergili, Ilda; Gönder, Z Beril; Yilmaz, Gulsum

    2016-04-01

    In this study, the effects of organic loading rate (OLR) and the addition of powdered activated carbon (PAC) on the performance and membrane fouling of MBR were conducted to treat real pharmaceutical process wastewater. Over 145 days of operation, the MBR system was operated at OLRs ranging from 1 to 2 kg COD m(-3) day(-1) without sludge wasting. The addition of PAC provided an improvement in the flux, despite an increase in the OLR:PAC ratio. The results demonstrated that the hybrid PAC-MBR system maintained a reduced amount of membrane fouling and steadily increased the removal performance of etodolac. PAC addition reduced the deposition of extracellular polymeric substance and organic matter on the membrane surface and resulted an increase in COD removal even at higher OLRs with low PAC addition. Membrane fouling mechanisms were investigated using combined adsorption fouling models. Modified fouling index values and normalized mass transfer coefficient values indicated that predominant fouling mechanism was cake adsorption.

  5. Improvement of photovoltaic properties by addition of a perylene compound in P3HT:PCBM BHJ system.

    PubMed

    Jeong, Seonju; Woo, Sung-Ho; Lyu, Hong-Kun; Kim, Charm; Kim, Hoyoung; Han, Yoon Soo

    2012-05-01

    The synthesized n-type perylene derivative, N,N'-bis-(4-bromophenyl)-1,6,7,12-tetrakis(4-n-butoxy-phenoxy)-3,4,9,10-perylene tetracarboxdiimide (PIBr), was applied as an additive to polymer solar cells (PSCs) with P3HT [poly(3-hexylthiophene)]:PCBM [[6,6]-phenyl C61-butyric acid methyl ester] blend films. Without post thermal annealing, a considerable improvement of about 98% in power conversion efficiency was achieved by the addition of 1 wt% PIBr into a P3HT:PCBM layer, when compared with that of reference cell without the additive. The results, in combination with relevant data from UV-Vis. absorption, photoluminescence, X-ray measurements and carrier mobility studies, revealed that the addition of the perylene compound within active layer contributed to more effective charge transfer and enhanced electron mobility.

  6. Understanding the Role of Additives in Improving the Performance of Polymer:Fullerene Bulk Heterojunction Solar Cells

    NASA Astrophysics Data System (ADS)

    Chen, Wei

    2014-03-01

    Solar cells based on the polymer:fullerene bulk heterojunction (BHJ) represent one of the most promising technologies for next-generation solar energy conversion due to their low-cost and scalability. In the last fifteen years, research efforts have led to organic photovoltaic (OPV) devices with power conversion efficiencies (PCEs) ~ 12%, but these values are still insufficient for the devices to become widely marketable. To further improve solar cell performance, a thorough understanding of the complex processing-structure-performance relationships in OPV devices is required. Recently, the use of processing additives have been proved to be one of the most effective methods to tune the nanomorphology of polymer:fullerene active layer, as the incorporation of a small percentage of solvent additives results in a nearly doubling of device efficiency. However, the physics behind these improved performances by processing additives still remains unclear. In this work, by taking advantage of resonant soft x-ray scattering (RSoXS) and energy-filtered transmission electron microscopy (EFTEM), we have determined that the solvent additives induce the change in the formation mechanism of polymer:fullerene nanomorphologies in the process of film casting. Progress established in the course of these studies on structural and morphological characterizations will serve as the foundation for further improving the efficiency of polymer solar cells to realize their large-scale commercial use.

  7. Method and apparatus for improved melt flow during continuous strip casting

    DOEpatents

    Follstaedt, D.W.; King, E.L.; Schneider, K.C.

    1991-11-12

    The continuous casting of metal strip using the melt overflow process is improved by controlling the weir conditions in the nozzle to provide a more uniform flow of molten metal across the width of the nozzle and reducing the tendency for freezing of metal along the interface with refractory surfaces. A weir design having a sloped rear wall and tapered sidewalls and critical gap controls beneath the weir has resulted in the drastic reduction in edge tearing and a significant improvement in strip uniformity. The floor of the container vessel is preferably sloped and the gap between the nozzle and the rotating substrate is critically controlled. The resulting flow patterns observed with the improved casting process have reduced thermal gradients in the bath, contained surface slag and eliminated undesirable solidification near the discharge area by increasing the flow rates at those points. 8 figures.

  8. Method and apparatus for improved melt flow during continuous strip casting

    DOEpatents

    Follstaedt, Donald W.; King, Edward L.; Schneider, Ken C.

    1991-11-12

    The continuous casting of metal strip using the melt overflow process is improved by controlling the weir conditions in the nozzle to provide a more uniform flow of molten metal across the width of the nozzle and reducing the tendency for freezing of metal along the interface with refractory surfaces. A weir design having a sloped rear wall and tapered sidewalls and critical gap controls beneath the weir has resulted in the drastic reduction in edge tearing and a significant improvement in strip uniformity. The floor of the container vessel is preferably sloped and the gap between the nozzle and the rotating substrate is critically controlled. The resulting flow patterns observed with the improved casting process have reduced thermal gradients in the bath, contained surface slag and eliminated undesirable solidification near the discharge area by increasing the flow rates at those points.

  9. Oral antioxidants improve leg blood flow during exercise in patients with chronic obstructive pulmonary disease.

    PubMed

    Rossman, Matthew J; Trinity, Joel D; Garten, Ryan S; Ives, Stephen J; Conklin, Jamie D; Barrett-O'Keefe, Zachary; Witman, Melissa A H; Bledsoe, Amber D; Morgan, David E; Runnels, Sean; Reese, Van R; Zhao, Jia; Amann, Markus; Wray, D Walter; Richardson, Russell S

    2015-09-01

    The consequence of elevated oxidative stress on exercising skeletal muscle blood flow as well as the transport and utilization of O2 in patients with chronic obstructive pulmonary disease (COPD) is not well understood. The present study examined the impact of an oral antioxidant cocktail (AOC) on leg blood flow (LBF) and O2 consumption during dynamic exercise in 16 patients with COPD and 16 healthy subjects. Subjects performed submaximal (3, 6, and 9 W) single-leg knee extensor exercise while LBF (Doppler ultrasound), mean arterial blood pressure, leg vascular conductance, arterial O2 saturation, leg arterial-venous O2 difference, and leg O2 consumption (direct Fick) were evaluated under control conditions and after AOC administration. AOC administration increased LBF (3 W: 1,604 ± 100 vs. 1,798 ± 128 ml/min, 6 W: 1,832 ± 109 vs. 1,992 ± 120 ml/min, and 9W: 2,035 ± 114 vs. 2,187 ± 136 ml/min, P < 0.05, control vs. AOC, respectively), leg vascular conductance, and leg O2 consumption (3 W: 173 ± 12 vs. 210 ± 15 ml O2/min, 6 W: 217 ± 14 vs. 237 ± 15 ml O2/min, and 9 W: 244 ± 16 vs 260 ± 18 ml O2/min, P < 0.05, control vs. AOC, respectively) during exercise in COPD, whereas no effect was observed in healthy subjects. In addition, the AOC afforded a small, but significant, improvement in arterial O2 saturation only in patients with COPD. Thus, these data demonstrate a novel beneficial role of AOC administration on exercising LBF, O2 consumption, and arterial O2 saturation in patients with COPD, implicating oxidative stress as a potential therapeutic target for impaired exercise capacity in this population.

  10. Oral antioxidants improve leg blood flow during exercise in patients with chronic obstructive pulmonary disease

    PubMed Central

    Rossman, Matthew J.; Trinity, Joel D.; Garten, Ryan S.; Ives, Stephen J.; Conklin, Jamie D.; Barrett-O'Keefe, Zachary; Witman, Melissa A. H.; Bledsoe, Amber D.; Morgan, David E.; Runnels, Sean; Reese, Van R.; Zhao, Jia; Amann, Markus; Wray, D. Walter

    2015-01-01

    The consequence of elevated oxidative stress on exercising skeletal muscle blood flow as well as the transport and utilization of O2 in patients with chronic obstructive pulmonary disease (COPD) is not well understood. The present study examined the impact of an oral antioxidant cocktail (AOC) on leg blood flow (LBF) and O2 consumption during dynamic exercise in 16 patients with COPD and 16 healthy subjects. Subjects performed submaximal (3, 6, and 9 W) single-leg knee extensor exercise while LBF (Doppler ultrasound), mean arterial blood pressure, leg vascular conductance, arterial O2 saturation, leg arterial-venous O2 difference, and leg O2 consumption (direct Fick) were evaluated under control conditions and after AOC administration. AOC administration increased LBF (3 W: 1,604 ± 100 vs. 1,798 ± 128 ml/min, 6 W: 1,832 ± 109 vs. 1,992 ± 120 ml/min, and 9W: 2,035 ± 114 vs. 2,187 ± 136 ml/min, P < 0.05, control vs. AOC, respectively), leg vascular conductance, and leg O2 consumption (3 W: 173 ± 12 vs. 210 ± 15 ml O2/min, 6 W: 217 ± 14 vs. 237 ± 15 ml O2/min, and 9 W: 244 ± 16 vs 260 ± 18 ml O2/min, P < 0.05, control vs. AOC, respectively) during exercise in COPD, whereas no effect was observed in healthy subjects. In addition, the AOC afforded a small, but significant, improvement in arterial O2 saturation only in patients with COPD. Thus, these data demonstrate a novel beneficial role of AOC administration on exercising LBF, O2 consumption, and arterial O2 saturation in patients with COPD, implicating oxidative stress as a potential therapeutic target for impaired exercise capacity in this population. PMID:26188020

  11. Separation of silver nanoparticles by hollow fiber flow field-flow fractionation: Addition of tannic acid into carrier liquid as a modifier.

    PubMed

    Saenmuangchin, Rattaporn; Mettakoonpitak, Jaruwan; Shiowatana, Juwadee; Siripinyanond, Atitaya

    2015-10-09

    A homemade hollow fiber flow-field fractionation (Hf-FlFFF) coupled with inductively coupled plasma mass spectrometry (ICP-MS) was set-up for silver nanoparticles (AgNPs) separation by using polysulfone hollow fiber membrane (30,000 MW cutoff) as a separation channel. Tannic acid and citrate stabilized AgNPs were synthesized and introduced into Hf-FlFFF. The effects of carrier liquid and stabilizing agent on retention behavior of AgNPs were investigated. Different elution behaviors were observed as follows: with 0.02% (w/v) FL-70, all of AgNPs were eluted from Hf-FlFFF but differences in retention behaviors were observed for AgNPs with tannic acid and citrate stabilizing agents; and with 30mM TRIS buffer, only tannic acid stabilized AgNPs were eluted from Hf-FlFFF, whereas citrate stabilized AgNPs were not eluted. In this work, tannic acid addition into carrier liquid was proposed to modify the surface of AgNPs and the surface of the membrane, and thereby adjusting the retention behaviors of AgNPs. Various concentrations of tannic acid were added into FL-70 and TRIS buffer. With the use of 0.1mM tannic acid in 30mM TRIS buffer as the carrier liquid, retention behaviors of both tannic acid stabilized- and citrate stabilized-AgNPs were similar and with similar fractionation recovery.

  12. Facilitators and barriers to the implementation of patient flow improvement strategies.

    PubMed

    Van Dyke, Kevin J; McHugh, Megan; Yonek, Julie; Moss, Dina

    2011-01-01

    Patient flow improvement strategies have been effective in reducing emergency department (ED) crowding, but little guidance is available on the implementation process. By using a qualitative research design, our objective was to identify common facilitators and barriers to the implementation of patient flow improvement strategies and successful approaches for mitigating barriers. Six hospitals participated in an 18-month Urgent Matters learning network launched in October 2008. The hospitals selected strategies to improve patient flow that could be implemented within 3 months with measurable impact. Across 6 hospitals, 8 strategies were implemented. We conducted 2 rounds of key informant interviews with improvement teams, for a total of 129 interviews. Interviews were recorded, transcribed, and coded by using a grounded theory approach to identify common themes. Factors facilitating implementation included participation in the learning network and strategic selection of team members. Common challenges included staff resistance and entrenched organizational culture. Some of the challenges were mitigated through approaches such as staff education and department leaders' constant reinforcement. Our findings indicate that several facilitators and barriers are common to the implementation of different strategies. Leveraging facilitators and developing a strategy to address common barriers may leave hospital and ED leaders better prepared to implement patient flow improvement strategies.

  13. Sensory Property Improvement of Jokbal (Korean Pettitoes) Made from Frozen Pig Feet by Addition of Herbal Mixture.

    PubMed

    Hwang, Young-Jung; Hwang, Seol-A; Lee, Ju-Woon

    2016-01-01

    This study was conducted to improve sensory quality of Jokbal (Korean Pettitoes) made from frozen pig feet by addition of herbal mixture (glasswort, raspberry and Sansa powders). After adding herbal mixture, lipid oxidation (2-thiobarbituric acid values, TBARS), sensory property, and textural property were determined. Herbs were individually added into cooking soup at concentration of 6% (low concentration treatment, LCT) or 12% (high concentration treatment, HCT) of raw pig feet. Refrigerated pig feet were used as control. Thawed feet without any herbal mixture were used as freezing treatment (FT). TBARS in LCT or HCT were lower than that in FT, and showed the similar to that in Control. Addition of the herbal mixture was effective in improving the flavor and textural property of thawed feet by inhibiting lipid oxidation and protein denaturation in a dose-dependent manner.

  14. Sensory Property Improvement of Jokbal (Korean Pettitoes) Made from Frozen Pig Feet by Addition of Herbal Mixture

    PubMed Central

    Lee, Ju-Woon

    2016-01-01

    This study was conducted to improve sensory quality of Jokbal (Korean Pettitoes) made from frozen pig feet by addition of herbal mixture (glasswort, raspberry and Sansa powders). After adding herbal mixture, lipid oxidation (2-thiobarbituric acid values, TBARS), sensory property, and textural property were determined. Herbs were individually added into cooking soup at concentration of 6% (low concentration treatment, LCT) or 12% (high concentration treatment, HCT) of raw pig feet. Refrigerated pig feet were used as control. Thawed feet without any herbal mixture were used as freezing treatment (FT). TBARS in LCT or HCT were lower than that in FT, and showed the similar to that in Control. Addition of the herbal mixture was effective in improving the flavor and textural property of thawed feet by inhibiting lipid oxidation and protein denaturation in a dose-dependent manner. PMID:27499659

  15. Unmanned Aircraft Systems: Additional Actions Needed to Improve Management and Integration of DOD Efforts to Support Warfighter Needs

    DTIC Science & Technology

    2008-11-01

    Services, House of Representatives UNMANNED AIRCRAFT SYSTEMS Additional Actions Needed to Improve Management and Integration of DOD Efforts to...Armed Services, House of Representatives The Department of Defense’s (DOD) use of unmanned aircraft systems (UAS) continues to increase. In 2000...unmanned aircraft systems This is a work of the U.S. government and is not subject to copyright protection in the United States. It may be reproduced

  16. The Addition of Vascular Calcification Scores to Traditional Risk Factors Improves Cardiovascular Risk Assessment in Patients with Chronic Kidney Disease

    PubMed Central

    Diouf, Momar; Temmar, Mohamed; Renard, Cédric; Choukroun, Gabriel; Massy, Ziad A.

    2015-01-01

    Background Although a variety of non-invasive methods for measuring cardiovascular (CV) risk (such as carotid intima media thickness, pulse wave velocity (PWV), coronary artery and aortic calcification scores (measured either by CT scan or X-ray) and the ankle brachial index (ABI)) have been evaluated separately in chronic kidney disease (CKD) cohorts, few studies have evaluated these methods simultaneously. Here, we looked at whether the addition of non-invasive methods to traditional risk factors (TRFs) improves prediction of the CV risk in patients at different CKD stages. Methods We performed a prospective, observational study of the relationship between the outputs of non-invasive measurement methods on one hand and mortality and CV outcomes in 143 patients at different CKD stages on the other. During the follow-up period, 44 patients died and 30 CV events were recorded. We used Cox models to calculate the relative risk for outcomes. To assess the putative clinical value of each method, we also determined the categorical net reclassification improvement (NRI) and the integrated discrimination improvement. Results Vascular calcification, PWV and ABI predicted all-cause mortality and CV events in univariate analyses. However, after adjustment for TRFs, only aortic and coronary artery calcification scores were found to be significant, independent variables. Moreover, the addition of coronary artery calcification scores to TRFs improved the specificity of prediction by 20%. Conclusion The addition of vascular calcification scores (especially the coronary artery calcification score) to TRFs appears to improve CV risk assessment in a CKD population. PMID:26181592

  17. Improvement of durability of an organic photocatalyst in p-xylene oxygenation by addition of a Cu(II) complex†

    PubMed Central

    Yamada, Yusuke; Maeda, Kazuki; Ohkubo, Kei; Karlin, Kenneth D.; Fukuzumi, Shunichi

    2012-01-01

    The catalytic durability of an organic photocatalyst, 9-mesityl-10-methyl acridinium ion (Acr+–Mes), has been dramatically improved by the addition of [{tris(2-pyridylmethyl)amine}-CuII](ClO4)2 ([(tmpa)CuII]2+) in the photocatalytic oxygenation of p-xylene by molecular oxygen in acetonitrile. Such an improvement is not observed by the addition of Cu(ClO4)2 in the absence of organic ligands. The addition of [(tmpa)Cu]2+ in the reaction solution resulted in more than an 11 times higher turnover number (TON) compared with the TON obtained without [(tmpa)CuII]2+. In the photocatalytic oxygenation, a stoichiometric amount of H2O2 formation was observed in the absence of [(tmpa)CuII]2+, however, much less H2O2 formation was observed in the presence of [(tmpa)CuII]2+. The photocatalytic mechanism was investigated by laser flash photolysis measurements in order to detect intermediates. The reaction of O2˙− with [(tmpa)CuII]2+ monitored by UV-vis spectroscopy in propionitrile at 203 K suggested formation of [{(tmpa)CuII}2O2]2+, a transformation which is crucial for the overall 4-electron reduction of molecular O2 to water, and a key in the observed improvement in the catalytic durability of Acr+–Mes. PMID:22692585

  18. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Fletcher, James C. (Inventor); Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1992-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  19. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1993-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of the additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  20. Device specific analysis of neonatal aortic outflow cannula jet flows for improved cardiopulmonary bypass hemodynamics

    NASA Astrophysics Data System (ADS)

    Menon, Prahlad; Sotiropoulos, Fotis; Undar, Akif; Pekkan, Kerem

    2011-11-01

    Hemodynamically efficient aortic outflow cannulae can provide high blood volume flow rates at low exit force during extracorporeal circulation in pediatric or neonatal cardiopulmonary bypass repairs. Furthermore, optimal hemolytic aortic insertion configurations can significantly reduce risk of post-surgical neurological complications and developmental defects in the young patient. The methodology and results presented in this study serve as a baseline for design of superior aortic outflow cannulae based on a novel paradigm of characterizing jet-flows at different flow regimes. In-silico evaluations of multiple cannula tips were used to delineate baseline hemodynamic performance of the popular pediatric cannula tips in an experimental cuboidal test-rig, using PIV. High resolution CFD jet-flow simulations performed for various cannula tips in the cuboidal test-rig as well as in-vivo insertion configurations have suggested the existence of optimal surgically relevant characteristics such as cannula outflow angle and insertion depth for improved hemodynamic performance during surgery. Improved cannula tips were designed with internal flow-control features for decreased blood damage and increased permissible flow rates.

  1. Improvement in safety and cycle life of lithium-ion batteries by employing quercetin as an electrolyte additive

    NASA Astrophysics Data System (ADS)

    Lee, Meng-Lun; Li, Yu-Han; Yeh, Jien-Wei; Shih, Han C.

    2012-09-01

    Quercetin, an organic antioxidant, has been employed as an additive in lithium-ion cells to enhance the electrochemical performance to enhance the cycle life and the overcharging characteristics of LiPF6/EC + EMC + DMC (1 M) when used as an electrolyte. A LiCoO2/graphite full cell with 0.05% quercetin showed a significant improvement in safety associated with overcharging tolerance and thermal stability, without causing damage in C-rate capability, and even a small improvement in cycle life performance. The quercetin-containing lithium battery showed an improvement in its electrochemical properties with 92% capacity retention after 350 cycles from 2.8 to 4.3 V, at a rate of 1 C; compared to 85% capacity retention for a cell without quercetin operated under the same conditions. The electrochemical impedance spectroscopy (EIS) results for the LiCoO2 cathode show that the addition of 0.05% quercetin provides a significant suppression in the impedance of the cell after 60 cycles. The improvement might result from the formation of a passivation microstructure (from quercetin oxidation) on the electrode's surface. The quercetin-containing batteries provided long term cycling and a high safety performance, making them a viable power source for applications involving electric devices with significant safety requirements.

  2. [High Throughput Screening Analysis of Preservatives and Sweeteners in Carbonated Beverages Based on Improved Standard Addition Method].

    PubMed

    Wang, Su-fang; Liu, Yun; Gong, Li-hua; Dong, Chun-hong; Fu, De-xue; Wang, Guo-qing

    2016-02-01

    Simulated water samples of 3 kinds of preservatives and 4 kinds of sweeteners were formulated by using orthogonal design. Kernel independent component analysis (KICA) was used to process the UV spectra of the simulated water samples and the beverages added different amounts of the additive standards, then the independent components (ICs), i. e. the UV spectral profiles of the additives, and the ICs' coefficient matrices were used to establish UV-KICA-SVR prediction model of the simulated preservatives and sweeteners solutions using support vector regression (SVR) analysis. The standards added beverages samples were obtained by adding different amounts level of additives in carbonated beverages, their UV spectra were processed by KICA, then IC information represented to the additives and other sample matrix were obtained, and the sample background can be deducted by removing the corresponding IC, other ICs' coefficient matrices were used to estimate the amounts of the additives in the standard added beverage samples based on the UV-KICA-SVR model, while the intercept of linear regression equation of predicted amounts and the added amounts in the standard added samples is the additive content in the raw beverage sample. By utilization of chemometric "blind source separation" method for extracting IC information of the tested additives in the beverage and other sample matrix, and using SVR regression modeling to improve the traditional standard addition method, a new method was proposed for the screening of the preservatives and sweeteners in carbonated beverages. The proposed UV-KICA-SVR method can be used to determine 3 kinds of preservatives and 4 kinds of sweetener in the carbonate beverages with the limit of detection (LOD) are located with the range 0.2-1.0 mg · L⁻¹, which are comparable to that of the traditional high performance liquid chromatographic (HPLC) method.

  3. Juncture flow improvement for wing/pylon configurations by using CFD methodology

    NASA Technical Reports Server (NTRS)

    Gea, Lie-Mine; Chyu, Wei J.; Stortz, Michael W.; Chow, Chuen-Yen

    1993-01-01

    Transonic flow field around a fighter wing/pylon configuration was simulated by using an implicit upwinding Navier-Stokes flow solver (F3D) and overset grid technology (Chimera). Flow separation and local shocks near the wing/pylon junction were observed in flight and predicted by numerical calculations. A new pylon/fairing shape was proposed to improve the flow quality. Based on numerical results, the size of separation area is significantly reduced and the onset of separation is delayed farther downstream. A smoother pressure gradient is also obtained near the junction area. This paper demonstrates that computational fluid dynamics (CFD) methodology can be used as a practical tool for aircraft design.

  4. High resolution characterization of aquifers to improve flow and transport models of highly heterogeneous media

    NASA Astrophysics Data System (ADS)

    Dogan Diker, Mine

    Aquifers are the primary sources of clean drinking water. Pollution in aquifers is one of the most challenging and important environmental problems. It is not only extremely complex to map but also difficult to remediate. Flow and transport of water and pollutants in porous media requires detailed characterization of the properties of the media. The main property which controls the flow and transport is hydraulic conductivity (K), which can be defined as the ability of the media to let the water flow through. Intensive studies to map the distribution of hydraulic conductivity are necessary to model the plume migration. Conventional in-situ aquifer characterization techniques are invasive and lack the necessary high resolution. Therefore, novel methods are required to improve the methods to monitor and simulate the flow and transport through aquifers. This study introduces a combination of novel techniques to provide the necessary information related to porous media. The proposed method was tested at a highly heterogeneous site called the Macro Dispersion Experiment (MADE) site in Mississippi. The MADE site is a very well studied site where several large scale tracer tests were conducted in the 1980s and 1990s. The tracers used for these tests were monitored using more than 300 multi-level sampler (MLS) wells. Concentration measurements showed that the majority of the mass stayed near the injection area, whereas minute concentrations were measured further down-gradient. This behavior is significantly different from the simulations created using models based on the Advection-Dispersion Equation (ADE). This behavior and the inability to explain this using most models has led to a major debate in the hydrologic science community. The hypothesis of this study is that the ADE based models can reproduce simulations of the measured transport when the models are parameterized with sufficient high-resolution hydraulic conductivity data. Two novel high resolution

  5. Interim Columbia and Snake rivers flow improvement measures for salmon: Final Supplemental Environmental Impact Statement (SEIS)

    SciTech Connect

    Not Available

    1993-03-01

    Public comments are sought on this final SEIS, which supplements the 1992 Columbia River Salmon Flow Measures Options Analysis (OA)/Environmental Impact Statement (EIS). The Corps of Engineers, in cooperation with the Bonneville Power Administration and the Bureau of Reclamation proposes five alternatives to improve flows of water in the lower Columbia-Snake rivers in 1993 and future years to assist the migration of juvenile and adult anadromous fish past eight hydropower dams. These are: (1) Without Project (no action) Alternative, (2) the 1992 Operation, (3) the 1992 Operation with Libby/Hungry Horse Sensitivity, (4) a Modified 1992 Operation with Improvements to Salmon Flows from Dworshak, and (5) a Modified 1992 Operation with Upper Snake Sensitivity. Alternative 4, Modified 1992 Operations, has been identified as the preferred alternative.

  6. The electronic image stabilization technology research based on improved optical-flow motion vector estimation

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Ji, Ming; Zhang, Ying; Jiang, Wentao; Lu, Xiaoyan; Wang, Jiaoying; Yang, Heng

    2016-01-01

    The electronic image stabilization technology based on improved optical-flow motion vector estimation technique can effectively improve the non normal shift, such as jitter, rotation and so on. Firstly, the ORB features are extracted from the image, a set of regions are built on these features; Secondly, the optical-flow vector is computed in the feature regions, in order to reduce the computational complexity, the multi resolution strategy of Pyramid is used to calculate the motion vector of the frame; Finally, qualitative and quantitative analysis of the effect of the algorithm is carried out. The results show that the proposed algorithm has better stability compared with image stabilization based on the traditional optical-flow motion vector estimation method.

  7. An improved version of NCOREL: A computer program for 3-D nonlinear supersonic potential flow computations

    NASA Technical Reports Server (NTRS)

    Siclari, Michael J.

    1988-01-01

    A computer code called NCOREL (for Nonconical Relaxation) has been developed to solve for supersonic full potential flows over complex geometries. The method first solves for the conical at the apex and then marches downstream in a spherical coordinate system. Implicit relaxation techniques are used to numerically solve the full potential equation at each subsequent crossflow plane. Many improvements have been made to the original code including more reliable numerics for computing wing-body flows with multiple embedded shocks, inlet flow through simulation, wake model and entropy corrections. Line relaxation or approximate factorization schemes are optionally available. Improved internal grid generation using analytic conformal mappings, supported by a simple geometric Harris wave drag input that was originally developed for panel methods and internal geometry package are some of the new features.

  8. Atorvastatin preconditioning improves the forward blood flow in the no-reflow rats.

    PubMed

    Shao, Liang; Zhang, Yong; Ma, Aiqun; Zhang, Ping; Wu, Dayin; Li, Wenzhu; Wang, Jue; Liu, Kun; Wang, Zhaohui

    2014-02-01

    Atorvastatin is not only an antilipemic but also used as an anti-inflammatory medicine in heart disease. Our working hypothesis was that atorvastatin preconditioning could improve the forward blood flow in the no-reflow rats associated with inflammation. We investigated that two doses of atorvastatin preconditioning (20 and 5 mg/kg/day) could alleviate deterioration of early cardiac diastolic function in rats with inflammation detected by echocardiography and haemodynamics. This benefit was obtained from the effect of atorvastatin preconditioning on improving forward blood flow and preserving the infarct cardiomyocytes, which was estimated by Thioflavin S and TTC staining in rats with myocardial ischemia/reperfusion. Subsequently, the improving of forward blood flow was ascribed to reduction of microthrombus in microvascular and myocardial fibrosis observed by MSB and Masson's trichrome staining with atorvastatin preconditioning. Ultimately, we found that atorvastatin preconditioning could reduce inflammation factor, such as tumor necrosis factor-α and fibrinogen-like protein 2, both in myocardial and in mononuclear cells, which probably attribute to microcirculation dysfunction in no-reflow rats detected by immunohistochemistry staining, western blot, and ELISA detection, respectively. In conclusion, atorvastatin preconditioning could alleviate deterioration of early cardiac diastolic function and improve the forward blood flow in the no-reflow rats attributing to reduction of TNF-α and fgl-2 expression.

  9. Improving cash flow in a down economy. How HIM can help reduce denials.

    PubMed

    Dunn, Rose

    2009-03-01

    Maybe HIM professionals can't ease tight credit or reduce bad debt, but they can make sure their organizations get full, correct reimbursement on the first submission. HIM professionals help improve cash flow by contributing to revenue cycle management n these tough economic times-when increases in bad

  10. Improvement of mechanical and biological properties of TiNi alloys by addition of Cu and Co to orthodontic archwires.

    PubMed

    Phukaoluan, Aphinan; Khantachawana, Anak; Kaewtatip, Pongpan; Dechkunakorn, Surachai; Kajornchaiyakul, Julathep

    2016-09-01

    The purpose of this study was to investigate improved performances of TiNi in order to promote tooth movement. Special attention was paid to the effect on the clinical properties of TiNi of adding Cu and Co to this alloy. Ti49.4Ni50.6, Ti49Ni46Cu5 and Ti50Ni47Co3 (at %) alloys were prepared. Specimens were cold-rolled at 30% reduction and heat-treated at 400°C for 60min. Then, the test results were compared with two types of commercial archwires. The findings showed that superelasticity properties were confirmed in the manufactured commercial alloys at mouth temperature. The difference of stress plateau in TiNi, TiNiCo and commercial wires B at 25°C changed significantly at various testing temperatures due to the combination of martensite and austenite phases. At certain temperatures the alloys exhibited zero recovery stress at 2% strain and consequently produced zero activation force for moving teeth. The corrosion test showed that the addition of Cu and Co to TiNi alloys generates an increase in corrosion potential (Ecorr) and corrosion current densities (Icorr). Finally, we observed that addition of Cu and Co improved cell viability. We conclude that addition of an appropriate amount of a third alloying element can help enhance the performances of TiNi orthodontic archwires.

  11. The Evaluation of Triphenyl Phosphate as a Flame Retardant Additive to Improve the Safety of Lithium-Ion Battery Electrolytes

    NASA Technical Reports Server (NTRS)

    Smart, M. C.; Krause, F. C.; Hwang, C.; West, W. C.; Soler, J.; Prakash, G. K. S.; Ratnakumar, B. V.

    2011-01-01

    With the intent of improving the safety characteristics of lithium ion cells, electrolytes containing flame retardant additives have been investigated. A number of triphenyl phosphate-containing electrolytes were evaluated in both coin cells and experimental three electrode lithium-ion cells (containing reference electrodes). A number of chemistries were investigated, including MCMB carbon/LiNi(0.8)Co(0.2)O2 (NCO), graphite/LiNi(0.8)Co(0.15)Al(0.05)O2 (NCA), Li/Li(Li(0.17)Ni(0.25)Mn(0.58))O2, Li/LiNiMnCoO2 (NMC) and graphite/LiNiMnCoO2 (NMC), to study the effect that different electrolyte compositions have upon performance. A wide range of TPP-containing electrolytes were demonstrated to have good compatibility with the C/NCO, C/NCA, and Li/NMC systems, however, poor performance was initially observed with the high voltage C/NMC system. This necessitated the development of improved electrolytes with stabilizing additives, leading to formulations containing lithium bis(oxalato)borate (LiBOB) that displayed substantially improved performance.

  12. Improvements to a Flow Sensor for Liquid Bismuth-Fed Hall Thrusters

    NASA Technical Reports Server (NTRS)

    Bonds, Kevin; Polzin, Kurt A.

    2010-01-01

    Recently, there has been significant interest in using bismuth metal as a propellant in Hall Thrusters [1, 2]. Bismuth offers some considerable cost, weight, and space savings over the traditional propellant--xenon. Quantifying the performance of liquid metal-fed Hall thrusters requires a very precise measure of the low propellant flow rates [1, 2]. The low flow rates (10 mg/sec) and the temperature at which free flowing liquid bismuth exists (above 300 C) preclude the use of off-the-shelf flow sensing equipment [3]. Therefore a new type of sensor is required. The hotspot bismuth flow sensor, described in Refs. [1-5] is designed to perform a flow rate measurement by measuring the velocity at which a thermal feature moves through a flow chamber. The mass flow rate can be determined from the time of flight of the thermal peak, [4, 5]. Previous research and testing has been concerned mainly with the generation of the thermal peak and it's subsequent detection. In this paper, we present design improvements to the sensor concept; and the results of testing conducted to verify the functionality of these improvements. A ceramic material is required for the sensor body (see Fig. 1), which must allow for active heating of the bismuth flow channel to keep the propellant in a liquid state. The material must be compatible with bismuth and must be bonded to conductive elements to allow for conduction of current into the liquid metal and measurement of the temperature in the flow. The new sensor requires fabrication techniques that will allow for a very small diameter flow chamber, which is required to produce useful measurements. Testing of various materials has revealed several that are potentially compatible with liquid bismuth. Of primary concern in the fabrication and testing of a robust, working prototype, is the compatibility of the selected materials with one another. Specifically, the thermal expansion rates of the materials relative to the ceramic body cannot expand so

  13. Design of a Water Coupling Bolus with Improved Flow Distribution for Multielement Superficial Hyperthermia Applicators

    PubMed Central

    Arunachalam, Kavitha; Maccarini, Paolo F; Schlorff, Jaime L.; Birkelund, Yngve; Jacobsen, Svein; Stauffer, Paul R.

    2009-01-01

    A water bolus used in superficial hyperthermia couples the electromagnetic (EM) or acoustic energy into the target tissue and cools the tissue surface to minimize thermal hotspots and patient discomfort during treatment. Parametric analyses of the fluid pressure inside the bolus computed using 3D fluid dynamics simulations are used in this study to determine a bolus design with improved flow and surface temperature distributions for large area superficial heat applicators. The simulation results are used in the design and fabrication of a 19×32 cm prototype bolus with dual input-dual output (DIDO) flow channels. Sequential thermal images of the bolus surface temperature recorded for a step change in the circulating water temperature are used to assess steady state flow and surface temperature distributions across the bolus. Modeling and measurement data indicate substantial improvement in bolus flow and surface temperature distributions when changing from the previous single input-single output (SISO) to DIDO configuration. Temperature variation across the bolus at steady state was measured to be less than 0.8°C for the DIDO bolus compared to 1.5°C for the SISO waterbolus. The new DIDO bolus configuration maintains a nearly uniform flow distribution and low variation in surface temperature over a large area typically treated in superficial hyperthermia. PMID:19848618

  14. Improvement in Myocardial Function and Coronary Blood Flow in Ischemic Myocardium after Mannitol

    PubMed Central

    Willerson, James T.; Powell, Wm. John; Guiney, Timothy E.; Stark, James J.; Sanders, Charles A.; Leaf, Alexander

    1972-01-01

    The purpose of this study was to evaluate the effect of hyperosmolality on the performance of, and the collateral blood flow to, ischemic myocardium. The myocardial response to mannitol, a hyperosmolar agent which remains extracellular, was evaluated in anesthetized dogs. Mannitol was infused into the aortic roots of 31 isovolumic hearts and of 15 dogs on right heart bypass, before and during ischemia. Myocardial ischemia was produced by temporary ligation of either the proximal or mid-left anterior descending coronary artery. Mannitol significantly improved the depressed ventricular function curves which occurred with left anterior descending coronary artery occlusion. Mannitol also significantly lessened the S-T segment elevation (epicardial electrocardiogram) occurring during myocardial ischemia in the isovolumic hearts and this reduction was associated with significant increases in total coronary blood flow (P < 0.005) and with increased collateral coronary blood flow to the ischemia area (P < 0.005). Thus, increases in serum osmolality produced by mannitol result in the following beneficial changes during myocardial ischemia: (a) improved myocardial function, (b) reduced S-T segment elevation, (c) increased total coronary blood flow, and (d) increased collateral coronary blood flow. PMID:4640943

  15. Improving Power Production in Acetate-Fed Microbial Fuel Cells via Enrichment of Exoelectrogenic Organisms in Flow-Through Systems

    SciTech Connect

    Borole, Abhijeet P; Hamilton, Choo Yieng; Vishnivetskaya, Tatiana A; Leak, David; Andras, Calin

    2009-01-01

    An exoelectrogenic, biofilm-forming microbial consortium was enriched in an acetate-fed microbial fuel cell (MFC) using a flow-through anode coupled to an air-cathode. Multiple parameters known to improve MFC performance were integrated in one design including electrode spacing, specific electrode surface area, flow-through design, minimization of dead volume within anode chamber, and control of external resistance. In addition, continuous feeding of carbon source was employed and the MFC was operated at intermittent high flows to enable removal of non-biofilm forming organisms over a period of six months. The consortium enriched using the modified design and operating conditions resulted in a power density of 345 W m-3 of net anode volume (3650 mW m-2), when coupled to a ferricyanide cathode. The enriched consortium included -, -, -Proteobacteria, Bacteroidetes and Firmicutes. Members of the order Rhodocyclaceae and Burkholderiaceae (Azospira spp. (49%), Acidovorax spp. (11%) and Comamonas spp. (7%)), dominated the microbial consortium. Denaturing gradient gel electrophoresis (DGGE) analysis based on primers selective for Archaea suggested a very low abundance of methanogens. Limiting the delivery of the carbon source via continuous feeding corresponding to the maximum cathodic oxidation rates permitted in the flow-through, air-cathode MFC resulted in coulombic efficiencies reaching 88 5.7%.

  16. Improved Diffuse Fluorescence Flow Cytometer Prototype for High Sensitivity Detection of Rare Circulating Cells In Vivo

    NASA Astrophysics Data System (ADS)

    Pestana, Noah Benjamin

    Accurate quantification of circulating cell populations is important in many areas of pre-clinical and clinical biomedical research, for example, in the study of cancer metastasis or the immune response following tissue and organ transplants. Normally this is done "ex-vivo" by drawing and purifying a small volume of blood and then analyzing it with flow cytometry, hemocytometry or microfludic devices, but the sensitivity of these techniques are poor and the process of handling samples has been shown to affect cell viability and behavior. More recently "in vivo flow cytometry" (IVFC) techniques have been developed where fluorescently-labeled cells flowing in a small blood vessel in the ear or retina are analyzed, but the sensitivity is generally poor due to the small sampling volume. To address this, our group recently developed a method known as "Diffuse Fluorescence Flow Cytometry" (DFFC) that allows detection and counting of rare circulating cells with diffuse photons, offering extremely high single cell counting sensitivity. In this thesis, an improved DFFC prototype was designed and validated. The chief improvements were three-fold, i) improved optical collection efficiency, ii) improved detection electronics, and iii) development of a method to mitigate motion artifacts during in vivo measurements. In combination, these improvements yielded an overall instrument detection sensitivity better than 1 cell/mL in vivo, which is the most sensitive IVFC system reported to date. Second, development and validation of a low-cost microfluidic device reader for analysis of ocular fluids is described. We demonstrate that this device has equivalent or better sensitivity and accuracy compared a fluorescence microscope, but at an order-of-magnitude reduced cost with simplified operation. Future improvements to both instruments are also discussed.

  17. Large-scale Manufacturing of Nanoparticulate-based Lubrication Additives for Improved Energy Efficiency and Reduced Emissions

    SciTech Connect

    Erdemir, Ali

    2013-09-26

    This project was funded under the Department of Energy (DOE) Lab Call on Nanomanufacturing for Energy Efficiency and was directed toward the development of novel boron-based nanocolloidal lubrication additives for improving the friction and wear performance of machine components in a wide range of industrial and transportation applications. Argonne's research team concentrated on the scientific and technical aspects of the project, using a range of state-of-the art analytical and tribological test facilities. Argonne has extensive past experience and expertise in working with boron-based solid and liquid lubrication additives, and has intellectual property ownership of several. There were two industrial collaborators in this project: Ashland Oil (represented by its Valvoline subsidiary) and Primet Precision Materials, Inc. (a leading nanomaterials company). There was also a sub-contract with the University of Arkansas. The major objectives of the project were to develop novel boron-based nanocolloidal lubrication additives and to optimize and verify their performance under boundary-lubricated sliding conditions. The project also tackled problems related to colloidal dispersion, larger-scale manufacturing and blending of nano-additives with base carrier oils. Other important issues dealt with in the project were determination of the optimum size and concentration of the particles and compatibility with various base fluids and/or additives. Boron-based particulate additives considered in this project included boric acid (H{sub 3}BO{sub 3}), hexagonal boron nitride (h-BN), boron oxide, and borax. As part of this project, we also explored a hybrid MoS{sub 2} + boric acid formulation approach for more effective lubrication and reported the results. The major motivation behind this work was to reduce energy losses related to friction and wear in a wide spectrum of mechanical systems and thereby reduce our dependence on imported oil. Growing concern over greenhouse gas

  18. Numerical study of tree-level improved lattice gradient flows in pure Yang-Mills theory

    NASA Astrophysics Data System (ADS)

    Kamata, Norihiko; Sasaki, Shoichi

    2017-03-01

    We study several types of tree-level improvement in the Yang-Mills gradient flow method in order to reduce the lattice discretization errors in line with Fodor et al. [J. High Energy Phys. 09 (2014) 018., 10.1007/JHEP09(2014)018]. The tree-level O (a2) improvement can be achieved in a simple manner, where an appropriate weighted average is computed between the plaquette and clover-leaf definitions of the action density ⟨E (t )⟩ measured at every flow time t . We further develop the idea of achieving the tree-level O (a4) improvement within a usage of actions consisting of the 1 ×1 plaquette and 1 ×2 planar loop for both the flow and gauge actions. For testing our proposal, we present numerical results for ⟨E (t )⟩ obtained on gauge configurations generated with the Wilson and Iwasaki gauge actions at three lattice spacings (a ≈0.1 ,0.07 , and 0.05 fm). Our results show that tree-level improved flows significantly eliminate the discretization corrections on t2⟨E (t )⟩ in the relatively small-t regime for up to t ≳a2 . To demonstrate the feasibility of our tree-level improvement proposal, we also study the scaling behavior of the dimensionless combinations of the ΛMS ¯ parameter and the new reference scale tX, which is defined through tX2⟨E (tX)⟩=X for the smaller X , e.g., X =0.15 . It is found that √{t0.15 }ΛMS ¯ shows a nearly perfect scaling behavior as a function of a2 regardless of the types of gauge action and flow, after tree-level improvement is achieved up to O (a4) . Further detailed study of the scaling behavior exposes the presence of the remnant O (g2 na2) corrections, which are beyond the tree level. Although our proposal is not enough to eliminate all O (a2) effects, we show that the O (g2 na2) corrections can be well under control even by the simplest tree-level O (a2) improved flow.

  19. Improved geometric variables for predicting disturbed flow at the normal carotid bifurcation

    NASA Astrophysics Data System (ADS)

    Bijari, Payam B.; Antiga, Luca; Steinman, David A.

    2011-03-01

    Recent work from our group has shown the primacy of the bifurcation area ratio and tortuosity in determining the amount of disturbed flow at the carotid bifurcation, believed to be a local risk factor for the carotid atherosclerosis. We have also presented fast and reliable methods of extraction of geometry from routine 3D contrast-enhanced magnetic resonance angiography, as the necessary step along the way for large-scale trials of such local risk factors. In the present study, we refine our original geometric variables to better reflect the underlying fluid mechanical principles. Flaring of the bifurcation, leading to flow separation, is defined by the maximum relative expansion of the common carotid artery (CCA), proximal to the bifurcation apex. The beneficial effect of curvature on flow inertia, via its suppression of flow separation, is now characterized by the tortuosity of CCA as it enters the flare region. Based on data from 50 normal carotid bifurcations, multiple linear regressions of these new independent geometric predictors against the dependent disturbed flow burden reveals adjusted R2 values approaching 0.5, better than the values closer to 0.3 achieved using the original variables. The excellent scan-rescan reproducibility demonstrated for our earlier geometric variables is shown to be preserved for the new definitions. Improved prediction of disturbed flow by robust and reproducible vascular geometry offers a practical pathway to large-scale studies of local risk factors in atherosclerosis.

  20. Sequential approach to joint flow-seismic inversion for improved characterization of fractured media

    NASA Astrophysics Data System (ADS)

    Kang, Peter K.; Zheng, Yingcai; Fang, Xinding; Wojcik, Rafal; McLaughlin, Dennis; Brown, Stephen; Fehler, Michael C.; Burns, Daniel R.; Juanes, Ruben

    2016-02-01

    Seismic interpretation of subsurface structures is traditionally performed without any account of flow behavior. Here we present a methodology for characterizing fractured geologic reservoirs by integrating flow and seismic data. The key element of the proposed approach is the identification—within the inversion—of the intimate relation between fracture compliance and fracture transmissivity, which determine the acoustic and flow responses of a fractured reservoir, respectively. Owing to the strong (but highly uncertain) dependence of fracture transmissivity on fracture compliance, the modeled flow response in a fractured reservoir is highly sensitive to the geophysical interpretation. By means of synthetic models, we show that by incorporating flow data (well pressures and tracer breakthrough curves) into the inversion workflow, we can simultaneously reduce the error in the seismic interpretation and improve predictions of the reservoir flow dynamics. While the inversion results are robust with respect to noise in the data for this synthetic example, the applicability of the methodology remains to be tested for more complex synthetic models and field cases.

  1. Improvement of low-humidity performance of PEMFC by addition of hydrophilic SiO 2 particles to catalyst layer

    NASA Astrophysics Data System (ADS)

    Jung, Un Ho; Park, Ki Tae; Park, Eun Hee; Kim, Sung Hyun

    Hydrophilic SiO 2 particles are added to the catalyst layer of a fuel cell membrane-electrode assembly (MEA) to improve wettability and performance at low-humidity conditions. The SiO 2 added MEAs are prepared by spraying technique and the contact angle is measured by the sessile drop method. The effects of SiO 2 additions of 0, 20, 40 and 60 wt.% (based on Pt/C) are investigated for various relative humidity levels in the anode and the cathode. The increased wettability of the cathode catalyst layer exerts an adverse effect on cell performance by causing flooding; this result demonstrates the hydrophilicity of SiO 2. With 40 wt.% addition of SiO 2 to the anode catalyst layer, the current density at 0.6 V and 0% relative humidity of the anode is 93% of that at 100% relative humidity. By comparison, the performance of a cell using a MEA with no added SiO 2 is only 85% of that at 0% relative humidity. A MEA with SiO 2 addition in the anode gives a higher performance at 60% relative humidity of the cathode than one with an undoped MEA. Increased wettability of the anode catalyst layer caused by SiO 2 addition renders it easy to absorb water from back diffusion.

  2. Aerothermal modeling program. Phase 2, element A: Improved numerical methods for turbulent viscous recirculating flows

    NASA Technical Reports Server (NTRS)

    Karki, K. C.; Mongia, H. C.; Patankar, Suhas V.; Runchal, A. K.

    1987-01-01

    The objective of this effort is to develop improved numerical schemes for predicting combustor flow fields. Various candidate numerical schemes were evaluated, and promising schemes were selected for detailed assessment. The criteria for evaluation included accuracy, computational efficiency, stability, and ease of extension to multidimensions. The candidate schemes were assessed against a variety of simple one- and two-dimensional problems. These results led to the selection of the following schemes for further evaluation: flux spline schemes (linear and cubic) and controlled numerical diffusion with internal feedback (CONDIF). The incorporation of the flux spline scheme and direct solution strategy in a computer program for three-dimensional flows is in progress.

  3. Utilization of deep eutectic solvents as novel mobile phase additives for improving the separation of bioactive quaternary alkaloids.

    PubMed

    Tan, Ting; Zhang, Mingliang; Wan, Yiqun; Qiu, Hongdeng

    2016-01-01

    Deep eutectic solvents (DESs) were used as novel mobile phase additives to improve chromatographic separation of four quaternary alkaloids including coptisine chloride, sanguinarine, berberine chloride and chelerythrine on a C18 column. DESs as a new class of ionic liquids are renewably sourced, environmentally benign, low cost and easy to prepare. Seven DESs were obtained by mixing different hydrogen acceptors and hydrogen-bond donors. The effects of organic solvents, the concentration of DESs, the types of DESs and the pH values of the buffer solution on the separation of the analytes were investigated. The composition of acetonitrile and 1.0% deep eutectic solvents aqueous solution (pH 3.3, adjusted with hydrochloric acid) in a 32:68 (v/v) ratio was used as optimized mobile phase, with which four quaternary alkaloids were well separated. When a small amount of DESs was added in the mobile phase for the separation of alkaloids on the C18 column, noticeable improvements were distinctly observed such as decreasing peak tailing and improving resolution. The separation mechanism mediated by DESs as mobile phase additives can be attributed to combined effect of both hydrogen acceptors and hydrogen-bond donors. For example, choline chloride can effectively cover the residual silanols on silica surface and ethylene glycol can reduce the retention time of analytes. The proposed method has been applied to determine BerbC in Lanqin Chinese herbal oral solution and BerbC tablet. Utilization of DESs in mobile phase can efficiently improve separation and selectivity of analytes from complex samples.

  4. Phosphorus applications improved the soil microbial responses under nitrogen additions in Chinese fir plantations of subtropical China

    NASA Astrophysics Data System (ADS)

    Zhang, Xinyu; Li, Dandan; Yang, Yang; Tang, Yuqian; Wang, Huimin; Chen, Fusheng; Sun, Xiaomin

    2016-04-01

    Nitrogen (N) deposition and low soil phosphorus (P) content aggravate the P limitation in subtropical forest soils. However, the responses of soil microbial communities, enzyme kinetics, and N cycling genes to P additions in subtropical plantations are still not clear. The hypothesis that P application can alleviate the limitation and improve the soil microbial properties was tested by long term field experiment in the Chinese fir plantations in subtropical China. Thirty 20m×20m plots were established in November 2011 and six different treatments were randomly distributed with five replicates. The treatments are control (CK, no N and P application), low N addition (N1: 50 kg N ha-1 yr-1), high N addition (N2: 100 kg N ha-1 yr-1), P addition (P: 50 kg P ha-1 yr-1), low N and P addition (N1P: 50 kg N ha-1 yr-1 and 50 kg P ha-1 yr-1) and high N and P addition (N2P: 100 kg N ha-1 yr-1 and 50 kg P ha-1 yr-1). A suite of responses of soil microorganism across four years (2012-2015) during three seasons (spring, summer and autumn) were measured. Following 4 years of N amendments, fertilized soils were more acidic and had lower soil microbial biomass carbon contents than CK. However, P alleviated the soil acidification and increased the soil microbial biomass carbon contents. Increases in microbial PLFA biomarkers and exoenzyme kinetics in N fertilized plots were observed in the initial year (2013) but reduced since then (2014 and 2015). Whereas P amendments increased the soil PLFA biomarkers and exoenzyme kinetics through the four years except that the acid phosphatase activities declined after 3 years applications. P applications enhanced the soil N cycling by increases the abundances of nitrifiers (ammonia-oxidizing archea) and denitrifiers (nos Z, norG, and nirK). The bacterial and fungal residue carbons (calculated by amino sugar indicators) were higher under NP fertilizations than the other treatments. Our results suggest that P application could improve the soil

  5. Budesonide added to modified porcine surfactant Curosurf may additionally improve the lung functions in meconium aspiration syndrome.

    PubMed

    Mikolka, P; Mokrá, D; Kopincová, J; Tomčíková-Mikušiaková, L; Calkovská, A

    2013-01-01

    Severe meconium aspiration syndrome (MAS) in newborns is often treated by exogenous surfactant. Because its efficacy is reduced by meconium-induced inflammation, glucocorticoid budesonide was added into surfactant preparation Curosurf to enhance efficacy of the surfactant therapy in experimental model of MAS. Oxygen-ventilated rabbits were intratracheally given meconium (25 mg/ml, 4 ml/kg) to induce respiratory failure. Thirty minutes later, animals were treated by intratracheal budesonide (0.25 mg/kg) or surfactant lung lavage (10 ml/kg, 5 mg phospholipids/ml) repeated twice, followed by undiluted Curosurf (100 mg phospholipids/kg) or by the above mentioned surfactant treatment with the last surfactant dose fortified with budesonide (0.25 mg/kg) or were untreated. Animals were ventilated for additional 5 hours and respiratory parameters were measured regularly. After sacrificing animals, wet-dry lung weight ratio was evaluated and plasma levels of interleukins (IL)-1beta, -6, -8, and TNF-alpha were measured by ELISA method. Efficacy of the given therapies to enhance lung functions and to diminish lung edema formation and inflammation increased from budesonide-only and surfactant-only therapy to surfactant+budesonide therapy. Combined therapy improved gas exchange from 30 min of administration, and showed a longer-lasting effect than surfactant-only therapy. In conclusions, budesonide additionally improved the effects of exogenous surfactant in experimental MAS.

  6. Improving performance and cyclability of zinc-silver oxide batteries by using graphene as a two dimensional conductive additive.

    PubMed

    Ozgit, Dilek; Hiralal, Pritesh; Amaratunga, Gehan A J

    2014-12-10

    In this article, the use of reduced graphene oxide (rGO) as a high-surface-area conductive additive for enhancing zinc-silver oxide (Zn-Ag2O) batteries is reported for the first time. Specific capacity, rate capability and cyclability are all improved with the addition of 5% thermally reduced graphene oxide to the electrode. It is shown that the rGO morphology becomes more beneficial as the active materials tend toward the nanoscale. The combination results in a better utilization of the active material, which in turn improves the specific capacity of the zinc-silver oxide batteries by ca. 50%, as a result of the more intimate contact with the nano (∼50 nm) electrode particles. The resulting rGO network also creates a high-surface-area conducting template for ZnO electrodeposition upon discharge, significantly reducing the overall particle size of the ZnO deposit, thus inhibiting the formation of dendrites, and increasing the number of achievable cycles from 4 to >160 with a basic cellulose separator. The morphology of the electrodes and its electrochemical parameters are studied as a function of cycling.

  7. Finite element analysis of transonic flows in cascades: Importance of computational grids in improving accuracy and convergence

    NASA Technical Reports Server (NTRS)

    Ecer, A.; Akay, H. U.

    1981-01-01

    The finite element method is applied for the solution of transonic potential flows through a cascade of airfoils. Convergence characteristics of the solution scheme are discussed. Accuracy of the numerical solutions is investigated for various flow regions in the transonic flow configuration. The design of an efficient finite element computational grid is discussed for improving accuracy and convergence.

  8. An improved continuous flow analysis system for high-resolution field measurements on ice cores.

    PubMed

    Kaufmann, Patrik R; Federer, Urs; Hutterli, Manuel A; Bigler, Matthias; Schüpbach, Simon; Ruth, Urs; Schmitt, Jochen; Stocker, Thomas F

    2008-11-01

    Continuous flow analysis (CFA) is a well-established method to obtain information about impurity contents in ice cores as indicators of past changes in the climate system. A section of an ice core is continuously melted on a melter head supplying a sample water flow which is analyzed online. This provides high depth and time resolution of the ice core records and very efficient sample decontamination as only the inner part of the ice sample is analyzed. Here we present an improved CFA system which has been totally redesigned in view of a significantly enhanced overall efficiency and flexibility, signal quality, compactness, and ease of use. These are critical requirements especially for operations of CFA during field campaigns, e.g., in Antarctica or Greenland. Furthermore, a novel deviceto measure the total air content in the ice was developed. Subsequently, the air bubbles are now extracted continuously from the sample water flow for subsequent gas measurements.

  9. Human Factors Operability Timeline Analysis to Improve the Processing Flow of the Orion Spacecraft

    NASA Technical Reports Server (NTRS)

    Stambolian, Damon B.; Schlierf, Roland; Miller, Darcy; Posada, Juan; Haddock, Mike; Haddad, Mike; Tran, Donald; Henderon, Gena; Barth, Tim

    2011-01-01

    This slide presentation reviews the use of Human factors and timeline analysis to have a more efficient and effective processing flow. The solution involved developing a written timeline of events that included each activity within each functional flow block. Each activity had computer animation videos and pictures of the people involved and the hardware. The Human Factors Engineering Analysis Tool (HFEAT) was improved by modifying it to include the timeline of events. The HFEAT was used to define the human factors requirements and design solutions were developed for these requirements. An example of a functional flow block diagram is shown, and a view from one of the animations (i.e., short stack pallet) is shown and explained.

  10. Improvement in the Mechanical Behavior of Mechanically Alloyed Aluminum Using Short-Time NH3 Flow

    NASA Astrophysics Data System (ADS)

    Caballero, E. S.; Cintas, J.; Cuevas, F. G.; Montes, J. M.; Herrera-García, M.

    2016-12-01

    In order to study the influence of a short-time ammonia gas flow during mechanical alloying (MA) of aluminum powders, samples were prepared using a simple press and sinter method. All milling experiments were performed at room temperature for a total of 10 hours. A short-time ammonia flow was incorporated into the milling process, allowing for the appearance of nitrogen-rich second phases, mainly oxycarbonitride and oxynitride aluminum (Al3CON and Al5O6N, respectively), during powder sintering. Testing of the sintering parts showed that the use of a short-time ammonia gas flow during vacuum milling substantially improved the mechanical properties at room and high temperatures.

  11. Influence of low-frequency vibrations on blood flow improvement in human's limbs.

    PubMed

    Venslauskas, Mantas; Ostasevicius, Vytautas; Vilkinis, Paulius

    2017-01-01

    The fundamental cause of diabetic limbs' problem is insufficient blood supply. The aim of the current work was to experimentally and numerically investigate the blood flow velocity and pressure changes in the channel during vibrational excitation. The micro-scale Particle Image Velocimetry (μPIV) technique as well as corresponding numerical channel model in COMSOL Multiphysics software were used to investigate the influence of external vibrations. Momentum upstream flow were noted on the fluid that was influenced by vibrations. Furthermore, momentum flow velocity increased by more than 3 times in both experimentally and theoretically. These results show that suggested novel low-frequency vibrational excitation method should be investigated in clinical studies in case of improvement of blood circulation in human limbs.

  12. Improving the performance of a compression ignition engine by directing flow of inlet air

    NASA Technical Reports Server (NTRS)

    Kemper, Carlton

    1946-01-01

    The object of this report is to present the results of tests performed by the National Advisory Committee for Aeronautics to determine the effect on engine performance of directing the flow of the inlet air to a 5-inch by 7-inch cylinder, solid injection, compression ignition engine, After a few preliminary tests, comparative runs were made at a speed of 1500 r.p.m. with and without directed air flow. It was found that directing the flow of the inlet air toward the fuel injection valve gave steadier engine operation, and an appreciable increase in power, and decreased fuel consumption. The results indicate the possibility of improving the performance of a given type of combustion chamber without changing its shape and with no change in valve timing. They would also seem to prove that directional turbulence, set up before the inlet valve of a four-stroke cycle engine, continues in the engine cylinder throughout the compression stroke.

  13. Evaluation of Next Generation Thermal Stability-Improving Additives for JP-8, Phase 1, Thermal Stability Impact Characterization

    DTIC Science & Technology

    2012-04-01

    the field, performance in combustor and nozzle tests, and altitude relight characteristics are critical ele- ments that determine an additive’s...represents fuel flow through the engine to the combustor nozzles that is used for propulsion. The recirculation fuel flow is flow that is recycled...in the combustor nozzle that controls fuel flow between primary and second- ary nozzle orifices. At this location, the fuel is at a significantly

  14. Stability improvement of natural food colors: Impact of amino acid and peptide addition on anthocyanin stability in model beverages.

    PubMed

    Chung, Cheryl; Rojanasasithara, Thananunt; Mutilangi, William; McClements, David Julian

    2017-03-01

    Anthocyanins are prone to chemical degradation and color fading in the presence of vitamin C. The potential of three amino acids (l-phenylalanine, l-tyrosine, l-tryptophan) and a polypeptide (ε-poly-l-lysine) in prolonging the color stability of purple carrot anthocyanins (0.025%) in model beverages (0.05% l-ascorbic acid, citric acid, pH 3.0) stored at elevated temperature (40°C/7 days) was examined. In the absence of amino acids or peptides, anthocyanin degraded at first-order reaction rate. Addition of amino acids or peptide (0.1%) increased the color stability of anthocyanins, with the most significant improvement observed for l-tryptophan. The average half-life of anthocyanin color increased from 2 days to 6 days with l-tryptophan addition. Fluorescence quenching measurements revealed that the l-tryptophan interacted with anthocyanins mainly through hydrogen bonding, although some hydrophobic interaction may also have been involved. Overall, this study suggests that amino acid or peptide addition may prolong the color stability of anthocyanin in beverage products.

  15. Improvement of the fermentative activity of lactic acid bacteria starter culture by the addition of Mn²⁺.

    PubMed

    Cheng, Xin; Dong, Ying; Su, Ping; Xiao, Xiang

    2014-11-01

    Production of lactic acid bacteria (LAB) starter with raw material has received much scientific investigation, but little information is available on the influences of some trace elements on the growth and fermentative activity of LAB. Based on this fact, this paper aimed to investigate the effects of Mn(2+) on the performance of Lactobacillus plantarum CX-15 starter with Jerusalem artichoke (JA) as the main medium substrate. The results showed that Mn(2+) addition had a significant beneficial affect on the fermentative activity of L. plantarum CX-15 starter. In contrast, the lack of Mn(2+) would cause the subsequent fermentation significantly slower, whether the cell density in starter culture was higher or lower. The possible mechanism of these phenomenons was further elucidated by the time course analysis of the specific activities of metabolism key enzymes during the culture processes of L. plantarum CX-15 starter. Compared to the fermentation processes without Mn(2+) addition, it was found that Mn(2+) addition would enhance the lactate dehydrogenase (LDH) activity but reduce the activities of pyruvate dehydrogenase (PDH) and ATPase activity. Therefore, it could be concluded that the improvement of L. plantarum starter fermentative activity was probably a consequence of Mn(2+) acting as "metabolic switch," which regulated the metabolic flux from pyruvic acid to lactic acid and other metabolism pathway.

  16. Overview of the Icing and Flow Quality Improvements Program for the NASA Glenn Icing Research Tunnel

    NASA Technical Reports Server (NTRS)

    Irvine, Thomas B.; Kevdzija, Susan L.; Sheldon, David W.; Spera, David A.

    2001-01-01

    Major upgrades were made in 1999 to the 6- by 9-Foot (1.8- by 2.7-m) Icing Research Tunnel (IRT) at the NASA Glenn Research Center. These included replacement of the electronic controls for the variable-speed drive motor, replacement of the heat exchanger, complete replacement and enlargement of the leg of the tunnel containing the new heat-exchanger, the addition of flow-expanding and flow-contracting turning vanes upstream and downstream of the heat exchanger, respectively, and the addition of fan outlet guide vanes (OGV's). This paper describes the rationale behind this latest program of IRT upgrades and the program's requirements and goals. An overview is given of the scope of work undertaken by the design and construction contractors, the scale-model IRT (SMIRT) design verification program, the comprehensive reactivation test program initiated upon completion of construction, and the overall management approach followed.

  17. Improving flow patterns and spillage characteristics of a box-type commercial kitchen hood.

    PubMed

    Huang, Rong Fung; Chen, Jia-Kun; Han, Meng-Ji; Priyambodo, Yusuf

    2014-01-01

    A conventional box-type commercial kitchen hood and its improved version (termed the "IQV commercial kitchen hood") were studied using the laser-assisted smoke flow visualization technique and tracer-gas (sulfur hexafluoride) detection methods. The laser-assisted smoke flow visualization technique qualitatively revealed the flow field of the hood and the areas apt for leakages of hood containment. The tracer-gas concentration detection method measured the quantitative leakage levels of the hood containment. The oil mists that were generated in the conventional box-type commercial kitchen hood leaked significantly into the environment from the areas near the front edges of ceiling and side walls. Around these areas, the boundary-layer separation occurred, inducing highly unsteady and turbulent recirculating flow, and leading to spillages of hood containment due to inappropriate aerodynamic design at the front edges of the ceiling and side walls. The tracer-gas concentration measurements on the conventional box-type commercial kitchen hood showed that the sulfur hexafluoride concentrations detected at the hood face attained very large values on an order of magnitude about 10(3)-10(4) ppb. By combining the backward-offset narrow suction slot, deflection plates, and quarter-circular arcs at the hood entrance, the IQV commercial kitchen hood presented a flow field containing four backward-inclined cyclone flow structures. The oil mists generated by cooking were coherently confined in these upward-rising cyclone flow structures and finally exhausted through the narrow suction slot. The tracer-gas concentration measurements on the IQV commercial kitchen hood showed that the order of magnitude of the sulfur hexafluoride concentrations detected at the hood face is negligibly small--only about 10(0) ppb across the whole hood face.

  18. DSMC simulation of hypersonic flows using an improved SBT-TAS technique

    NASA Astrophysics Data System (ADS)

    Goshayeshi, Bijan; Roohi, Ehsan; Stefanov, Stefan

    2015-12-01

    The current paper examines a new DSMC approach to hypersonic flow simulation consisting of a combination between the Simplified Bernoulli Trials (SBT) collision algorithm and the transient adaptive subcell (TAS) selection procedure. The SBT collision algorithm has already been introduced as a scheme that provides accurate results with a quite small number of particles per cells and its combination with the transient adaptive subcell (TAS) technique will enable SBT to have coarser grid sizes as well. In the current research, the no-time-counter (NTC) collision algorithm and nearest neighbor (NN) pair selection procedure of Bird DS2V code are substituted by the SBT-TAS and comparisons between the new algorithm and NTC-NN are made considering appropriate test cases including hypersonic cylinder flow and axisymmetric biconic flow. Hypersonic cylinder flow is a well-known benchmark problem with a wide collision frequency range while the biconic flow exhibits laminar shock/shock and shock/boundary-layer interactions. Improvements implemented in the SBT-TAS technique, including subcell volume estimation, surface properties filter, and time controller, are discussed in detail. The simulations of these hypersonic test cases demonstrated that from the viewpoint of consumed sample-size, SBT-TAS is an efficient collision technique.

  19. Active Gaze Control Improves Optic Flow-Based Segmentation and Steering

    PubMed Central

    Raudies, Florian; Mingolla, Ennio; Neumann, Heiko

    2012-01-01

    An observer traversing an environment actively relocates gaze to fixate objects. Evidence suggests that gaze is frequently directed toward the center of an object considered as target but more likely toward the edges of an object that appears as an obstacle. We suggest that this difference in gaze might be motivated by specific patterns of optic flow that are generated by either fixating the center or edge of an object. To support our suggestion we derive an analytical model that shows: Tangentially fixating the outer surface of an obstacle leads to strong flow discontinuities that can be used for flow-based segmentation. Fixation of the target center while gaze and heading are locked without head-, body-, or eye-rotations gives rise to a symmetric expansion flow with its center at the point being approached, which facilitates steering toward a target. We conclude that gaze control incorporates ecological constraints to improve the robustness of steering and collision avoidance by actively generating flows appropriate to solve the task. PMID:22719889

  20. Improved Measurement of B(sub 22) of Macromolecules in a Flow Cell

    NASA Technical Reports Server (NTRS)

    Wilson, Wilbur; Fanguy, Joseph; Holman, Steven; Guo, Bin

    2008-01-01

    An improved apparatus has been invented for use in determining the osmotic second virial coefficient of macromolecules in solution. In a typical intended application, the macromolecules would be, more specifically, protein molecules, and the protein solution would be pumped through a flow cell to investigate the physical and chemical conditions that affect crystallization of the protein in question. Some background information is prerequisite to a meaningful description of the novel aspects of this apparatus. A method of determining B22 from simultaneous measurements of the static transmittance (taken as an indication of concentration) and static scattering of light from the same location in a flowing protein solution was published in 2004. The apparatus used to implement the method at that time included a dual-detector flow cell, which had two drawbacks: a) The amount of protein required for analysis of each solution condition was of the order of a milligram - far too large a quantity for a high-throughput analysis system, for which microgram or even nanogram quantities of protein per analysis are desirable. b) The design of flow cell was such that two light sources were used to probe different regions of the flowing solution. Consequently, the apparatus did not afford simultaneous measurements at the same location in the solution and, hence, did not guarantee an accurate determination of B22.

  1. Web-Based Predictive Analytics to Improve Patient Flow in the Emergency Department

    NASA Technical Reports Server (NTRS)

    Buckler, David L.

    2012-01-01

    The Emergency Department (ED) simulation project was established to demonstrate how requirements-driven analysis and process simulation can help improve the quality of patient care for the Veterans Health Administration's (VHA) Veterans Affairs Medical Centers (VAMC). This project developed a web-based simulation prototype of patient flow in EDs, validated the performance of the simulation against operational data, and documented IT requirements for the ED simulation.

  2. Improved method of determining flow parameters in a hotshot wind tunnel

    NASA Astrophysics Data System (ADS)

    Gavrishev, A. A.; Tsyryulnikov, I. S.

    2016-10-01

    In this article, an improved algorithm of calculating the free-stream parameters in the test section of the hotshot wind tunnel is purposed. This algorithm accounts real gas effects and heat losses, by including experimental values of the flow velocity as a function of the gas exhaustion time. To obtain these data, we realized a two-beam time-of-flight method of velocity measurement.

  3. An additional aromatic interaction improves the thermostability and thermophilicity of a mesophilic family 11 xylanase: structural basis and molecular study.

    PubMed Central

    Georis, J.; de Lemos Esteves, F.; Lamotte-Brasseur, J.; Bougnet, V.; Devreese, B.; Giannotta, F.; Granier, B.; Frère, J. M.

    2000-01-01

    In a general approach to the understanding of protein adaptation to high temperature, molecular models of the closely related mesophilic Streptomyces sp. S38 Xyl1 and thermophilic Thermomonospora fusca TfxA family 11 xylanases were built and compared with the three-dimensional (3D) structures of homologous enzymes. Some of the structural features identified as potential contributors to the higher thermostability of TfxA were introduced in Xyl1 by site-directed mutagenesis in an attempt to improve its thermostability and thermophilicity. A new Y11-Y16 aromatic interaction, similar to that present in TfxA and created in Xyl1 by the T11Y mutation, improved both the thermophilicity and thermostability. Indeed, the optimum activity temperature (70 vs. 60 degrees C) and the apparent Tm were increased by about 9 degrees C, and the mutant was sixfold more stable at 57 degrees C. The combined mutations A82R/F168H/N169D/delta170 potentially creating a R82-D169 salt bridge homologous to that present in TfxA improved the thermostability but not the thermophilicity. Mutations R82/D170 and S33P seemed to be slightly destabilizing and devoid of influence on the optimal activity temperature of Xyl1. Structural analysis revealed that residues Y11 and Y16 were located on beta-strands B1 and B2, respectively. This interaction should increase the stability of the N-terminal part of Xyl1. Moreover, Y11 and Y16 seem to form an aromatic continuum with five other residues forming putative subsites involved in the binding of xylan (+3, +2, +1, -1, -2). Y11 and Y16 might represent two additional binding subsites (-3, -4) and the T11Y mutation could thus improve substrate binding to the enzyme at higher temperature and thus the thermophilicity of Xyl1. PMID:10752608

  4. Identifiability analysis and improvement of a tree water flow and storage model.

    PubMed

    De Pauw, D J W; Steppe, K; De Baets, B

    2008-02-01

    A recently published tree water flow and storage model (RCGro) for simulating water transport dynamics in trees and related stem diameter variations was improved in order to better describe a data set gathered under mild drought stress conditions. Model improvements were carried out based on the results of a mathematical identifiability analysis. This analysis provided important information with respect to the balance between model complexity and data availability. Using the identifiability analysis results, we were able to (1) highlight weaknesses of the model; (2) obtain information on how the model could be reduced in some places, to improve its identifiability properties, and extended in others, to enhance model performance; (3) identify which measurements are necessary to optimally calibrate the model. The resulting improved model was less complex (contained less unidentifiable parameters), had better dynamic properties and was able to better describe the stress data set.

  5. Additions to Magnetic Trackline Archive For Improvements to Earth Magnetic Anomaly Grid (EMAG2) and Improvements to Data Dissemination at NGDC

    NASA Astrophysics Data System (ADS)

    Meyer, B.; Jencks, J.; Barckhausen, U.; Ishihara, T.; Campagnoli, J.

    2014-12-01

    The National Geophysical Data Center (NGDC) is the primary archive of marine geophysical data worldwide. However, it has been challenging for scientist to discover and access data due to variable data formats, non-digital data holdings, and transitioning data discovery portals. In 2014, NGDC made a concerted effort to identify, ingest, and archive all publicly available magnetic trackline data for access via a new Trackline Geophysical Data web-based interface. Non-digital data were digitized and added to the Global Geophysical Database and are now available for download in a common MGD77 format. All ancillary and analog data are accessible via the same interface, without having to navigate through multiple directories or prompts. The result is over 16.5 million miles of magnetic trackline data are now available, both through NGDC's improved user interface and as a web service for incorporation into other portals. This allows the geoscience community unprecedented access to global geophysical magnetic trackline data from a secure long-term archive. The addition of 6.5 million miles of magnetic trackline data to the database, since the previous release of the Earth Magnetic Anomaly Grid (EMAG2), will give NGDC the ability to improve the model coverage, especially in areas of low coverage, such as around the Eltanin Fracture Zone in the South Pacific. This poster will focus on some key data additions and how they will help us validate the accuracy of the ocean age model/directional gridding algorithm and improve the Earth Magnetic Anomaly Grid going forward.

  6. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  7. PERFORMANCE IMPROVEMENT OF CROSS-FLOW FILTRATION FOR HIGH LEVEL WASTE TREATMENT

    SciTech Connect

    Duignan, M.; Nash, C.; Poirier, M.

    2011-01-12

    In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing cross-flow equipment. The Savannah River National Laboratory (SRNL) was included in those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Cross-flow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate slurries. This separation technology generally has the advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Modular Caustic Side Solvent Extraction Unit and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date increased rates are generally realized by either increasing the cross-flow filter axial flowrate, limited by pump capacity, or by increasing filter surface area, limited by space and increasing the required pump load. SRNL set up both dead-end and cross-flow filter tests to better understand filter performance based on filter media structure, flow conditions, filter cleaning, and several different types of filter aids and body feeds. Using non-radioactive simulated wastes, both chemically and physically similar to the actual radioactive wastes, the authors performed

  8. The Symbiotic Performance of Chickpea Rhizobia Can Be Improved by Additional Copies of the clpB Chaperone Gene.

    PubMed

    Paço, Ana; Brígido, Clarisse; Alexandre, Ana; Mateos, Pedro F; Oliveira, Solange

    2016-01-01

    The ClpB chaperone is known to be involved in bacterial stress response. Moreover, recent studies suggest that this protein has also a role in the chickpea-rhizobia symbiosis. In order to improve both stress tolerance and symbiotic performance of a chickpea microsymbiont, the Mesorhizobium mediterraneum UPM-Ca36T strain was genetically transformed with pPHU231 containing an extra-copy of the clpB gene. To investigate if the clpB-transformed strain displays an improved stress tolerance, bacterial growth was evaluated under heat and acid stress conditions. In addition, the effect of the extra-copies of the clpB gene in the symbiotic performance was evaluated using plant growth assays (hydroponic and pot trials). The clpB-transformed strain is more tolerant to heat shock than the strain transformed with pPHU231, supporting the involvement of ClpB in rhizobia heat shock tolerance. Both plant growth assays showed that ClpB has an important role in chickpea-rhizobia symbiosis. The nodulation kinetics analysis showed a higher rate of nodule appearance with the clpB-transformed strain. This strain also induced a greater number of nodules and, more notably, its symbiotic effectiveness increased ~60% at pH5 and 83% at pH7, compared to the wild-type strain. Furthermore, a higher frequency of root hair curling was also observed in plants inoculated with the clpB-transformed strain, compared to the wild-type strain. The superior root hair curling induction, nodulation ability and symbiotic effectiveness of the clpB-transformed strain may be explained by an increased expression of symbiosis genes. Indeed, higher transcript levels of the nodulation genes nodA and nodC (~3 folds) were detected in the clpB-transformed strain. The improvement of rhizobia by addition of extra-copies of the clpB gene may be a promising strategy to obtain strains with enhanced stress tolerance and symbiotic effectiveness, thus contributing to their success as crop inoculants, particularly under

  9. EFFECT OF OXYGEN ADDITION ON POLYCYCLIC AROMATIC HYDROCARBON FORMATION IN 1,3 BUTADIENE COUNTER-FLOW DIFFUSION FLAMES. (R828193)

    EPA Science Inventory

    The effect of 3% O2 addition to the fuel on detailed chemical structure of a 1,3 butadiene counter-flow diffusion flame has been investigated by using heated microprobe sampling and online gas chromatography mass spectrometry. Centerline gas temperature and species ...

  10. Addition of Al and Fe salts during treatment of paper mill effluents to improve activated sludge settlement characteristics.

    PubMed

    Agridiotis, V; Forster, C F; Carliell-Marquet, C

    2007-11-01

    Metal salts, ferrous sulphate and aluminium chloride, were added to laboratory-scale activated sludge plant treating paper mill effluents to investigate the effect on settlement characteristics. Before treatment the sludge was filamentous, had stirred sludge volume index (SSVI) values in excess of 300 and was moderately hydrophobic. The use of FeSO4.7H2O took three weeks to reduce the SSVI to 90. Microscopic examination showed that Fe had converted the filamentous flocs into a compact structure. When the iron dosing was stopped, the sludge returned to its bulking state within four weeks. In a subsequent trial, the addition of AlCl3 initially resulted in an improvement of the settlement index but then caused deterioration of the sludge properties. It is possible that aluminium was overdosed and caused charge reversal, increasing the SSVI.

  11. Optimization of a Y-graft design for improved hepatic flow distribution in the fontan circulation.

    PubMed

    Yang, Weiguang; Feinstein, Jeffrey A; Shadden, Shawn C; Vignon-Clementel, Irene E; Marsden, Alison L

    2013-01-01

    Single ventricle heart defects are among the most serious congenital heart diseases, and are uniformly fatal if left untreated. Typically, a three-staged surgical course, consisting of the Norwood, Glenn, and Fontan surgeries is performed, after which the superior vena cava (SVC) and inferior vena cava (IVC) are directly connected to the pulmonary arteries (PA). In an attempt to improve hemodynamic performance and hepatic flow distribution (HFD) of Fontan patients, a novel Y-shaped graft has recently been proposed to replace the traditional tube-shaped extracardiac grafts. Previous studies have demonstrated that the Y-graft is a promising design with the potential to reduce energy loss and improve HFD. However these studies also found suboptimal Y-graft performance in some patient models. The goal of this work is to determine whether performance can be improved in these models through further design optimization. Geometric and hemodynamic factors that influence the HFD have not been sufficiently investigated in previous work, particularly for the Y-graft. In this work, we couple Lagrangian particle tracking to an optimal design framework to study the effects of boundary conditions and geometry on HFD. Specifically, we investigate the potential of using a Y-graft design with unequal branch diameters to improve hepatic distribution under a highly uneven RPA/LPA flow split. As expected, the resulting optimal Y-graft geometry largely depends on the pulmonary flow split for a particular patient. The unequal branch design is demonstrated to be unnecessary under most conditions, as it is possible to achieve the same or better performance with equal-sized branches. Two patient-specific examples show that optimization-derived Y-grafts effectively improve the HFD, compared to initial nonoptimized designs using equal branch diameters. An instance of constrained optimization shows that energy efficiency slightly increases with increasing branch size for the Y-graft, but that a

  12. Improvements on digital inline holographic PTV for 3D wall-bounded turbulent flow measurements

    NASA Astrophysics Data System (ADS)

    Toloui, Mostafa; Mallery, Kevin; Hong, Jiarong

    2017-04-01

    Three-dimensional (3D) particle image velocimetry (PIV) and particle tracking velocimetry (PTV) provide the most comprehensive flow information for unraveling the physical phenomena in a wide range of fluid problems, from microfluidics to wall-bounded turbulent flows. Compared with other 3D PIV techniques, such as tomographic PIV and defocusing PIV, the digital inline holographic PTV (DIH-PTV) provides 3D flow measurement solution with high spatial resolution, low cost optical setup, and easy alignment and calibration. Despite these advantages, DIH-PTV suffers from major limitations including poor longitudinal resolution, human intervention (i.e. requirement for manually determined tuning parameters during tracer field reconstruction and extraction), limited tracer concentration, small sampling volume and expensive computations, limiting its broad use for 3D flow measurements. In this study, we present our latest developments on minimizing these challenges, which enables high-fidelity DIH-PTV implementation to larger sampling volumes with significantly higher particle seeding densities suitable for wall-bounded turbulent flow measurements. The improvements include: (1) adjustable window thresholding; (2) multi-pass 3D tracking; (3) automatic wall localization; and (4) continuity-based out-of-plane velocity component computation. The accuracy of the proposed DIH-PTV method is validated with conventional 2D PIV and double-view holographic PTV measurements in smooth-wall turbulent channel flow experiments. The capability of the technique in characterization of wall-bounded turbulence is further demonstrated through its application to flow measurements for smooth- and rough-wall turbulent channel flows. In these experiments, 3D velocity fields are measured within sampling volumes of 14.7  ×  50.0  ×  14.4 mm3 (covering the entire depth of the channel) with a velocity resolution of  <1.1 mm/vector. Overall, the presented DIH-PTV method and

  13. Improved efficiency in micellar liquid chromatography using triethylamine and 1-butanol as mobile phase additives to reduce surfactant adsorption.

    PubMed

    Thomas, David P; Foley, Joe P

    2008-09-26

    The effect of triethylamine as a mobile phase modifier on chromatographic efficiency in micellar liquid chromatography (MLC) is reported for nine different columns with various bonded stationary phases and silica pore sizes, including large-pore short alkyl chain, non-porous, and perfluorinated. Reduced plate height (h) versus reduced velocity (nu) plots were constructed for each column and the A' and C' terms calculated using a simplified Van Deemter equation introduced in our previous work. To further explore the practicality of using triethylamine in the micellar mobile phase, the efficiency of nine polar and non-polar substituted benzenes was studied on seven columns. Surfactant adsorption isotherms were measured for five columns with three micellar mobile phases to understand the relationship between adsorbed surfactant, mobile phase additive, and column efficiency. Clear improvements in efficiency were observed with the addition of 2% (v/v) triethylamine to a 1-butanol modified aqueous micellar mobile phase. This finding is supported by the lower amount of surfactant adsorbed onto the stationary phase when TEA is present in the mobile phase compared to an SDS only or a 1-butanol modified SDS mobile phase.

  14. Improvement of an integrated system of membrane bioreactor and worm reactor by phosphorus removal using additional post-chemical treatment.

    PubMed

    Liu, Jia; Zuo, Wei; Tian, Yu; Zhang, Jun; Li, Hui; Li, Lipin

    2016-11-01

    A membrane bioreactor (MBR) coupled with a worm reactor (SSBWR) was designed as SSBWR-MBR for sewage treatment and excess sludge reduction. However, total phosphorus (TP) release caused by worm predation in the SSBWR could increase the effluent TP concentration in the SSBWR-MBR. To decrease the amount of TP excreted, chemical treatment reactor was connected after the SSBWR-MBR to remove the excess phosphorus (P). The effects of chemical treatment at different time intervals on the performance of the SSBWR-MBR were assessed. The results showed that a maximum TP removal efficiency of 21.5 ± 1.0% was achieved in the SSBWR-MBR after chemical treatment. More importantly, a higher sulfate concentration induced by chemical treatment could promote TP release in the SSBWR, which provided further TP removal from the SSBWR-MBR. Additionally, chemical oxygen demand (COD) removal efficiency of the SSBWR-MBR was increased by 1.3% after effective chemical treatment. In the SSBWR-MBR, the chemical treatment had little effects on NH3-N removal and sludge production. Eventually, chemical treatment also alleviated the membrane fouling in the SSBWR-MBR. In this work, the improvement on TP, COD removal and membrane fouling alleviation was achieved in the SSBWR-MBR using additional chemical treatment.

  15. Investigation of cross-linked and additive containing polymer materials for membranes with improved performance in pervaporation and gas separation.

    PubMed

    Hunger, Katharina; Schmeling, Nadine; Jeazet, Harold B Tanh; Janiak, Christoph; Staudt, Claudia; Kleinermanns, Karl

    2012-10-22

    Pervaporation and gas separation performances of polymer membranes can be improved by crosslinking or addition of metal-organic frameworks (MOFs). Crosslinked copolyimide membranes show higher plasticization resistance and no significant loss in selectivity compared to non-crosslinked membranes when exposed to mixtures of CO2/CH4 or toluene/cyclohexane. Covalently crosslinked membranes reveal better separation performances than ionically crosslinked systems. Covalent interlacing with 3-hydroxypropyldimethylmaleimide as photocrosslinker can be investigated in situ in solution as well as in films, using transient UV/Vis and FTIR spectroscopy. The photocrosslinking yield can be determined from the FTIR-spectra. It is restricted by the stiffness of the copolyimide backbone, which inhibits the photoreaction due to spatial separation of the crosslinker side chains. Mixed-matrix membranes (MMMs) with MOFs as additives (fillers) have increased permeabilities and often also selectivities compared to the pure polymer. Incorporation of MOFs into polysulfone and Matrimid® polymers for MMMs gives defect-free membranes with performances similar to the best polymer membranes for gas mixtures, such as O2/N2 H2/CH4, CO2/CH4, H2/CO2, CH4/N2 and CO2/N2 (preferentially permeating gas is named first). The MOF porosity, its particle size and content in the MMM are factors to influence the permeability and the separation performance of the membranes.

  16. Investigation of Cross-Linked and Additive Containing Polymer Materials for Membranes with Improved Performance in Pervaporation and Gas Separation

    PubMed Central

    Hunger, Katharina; Schmeling, Nadine; Jeazet, Harold B. Tanh; Janiak, Christoph; Staudt, Claudia; Kleinermanns, Karl

    2012-01-01

    Pervaporation and gas separation performances of polymer membranes can be improved by crosslinking or addition of metal-organic frameworks (MOFs). Crosslinked copolyimide membranes show higher plasticization resistance and no significant loss in selectivity compared to non-crosslinked membranes when exposed to mixtures of CO2/CH4 or toluene/cyclohexane. Covalently crosslinked membranes reveal better separation performances than ionically crosslinked systems. Covalent interlacing with 3-hydroxypropyldimethylmaleimide as photocrosslinker can be investigated in situ in solution as well as in films, using transient UV/Vis and FTIR spectroscopy. The photocrosslinking yield can be determined from the FTIR-spectra. It is restricted by the stiffness of the copolyimide backbone, which inhibits the photoreaction due to spatial separation of the crosslinker side chains. Mixed-matrix membranes (MMMs) with MOFs as additives (fillers) have increased permeabilities and often also selectivities compared to the pure polymer. Incorporation of MOFs into polysulfone and Matrimid® polymers for MMMs gives defect-free membranes with performances similar to the best polymer membranes for gas mixtures, such as O2/N2 H2/CH4, CO2/CH4, H2/CO2, CH4/N2 and CO2/N2 (preferentially permeating gas is named first). The MOF porosity, its particle size and content in the MMM are factors to influence the permeability and the separation performance of the membranes. PMID:24958427

  17. An additional S-shaped structure for sensitivity improvement of coaxial probe for permittivity determination of low loss materials

    NASA Astrophysics Data System (ADS)

    Jiao, Xingmin; Jin, Wei; Yang, Xiaoqing

    2015-05-01

    Permittivity measurement of materials is important in microwave chemistry, microwave material processing and microwave heating. The open-ended coaxial line method is one of the most popular and effective means for permittivity measurement. However, the conventional coaxial probe has difficulty in distinguishing small permittivity variations for low loss media. In this paper an additional S-shaped structure is proposed for sensitivity improvement of a coaxial probe for permittivity determination of low loss materials at 2.45 GHz. The small permittivity variation can be distinguished due to field enhancement generated by the additional S-shaped structure. We studied the variation of reflection coefficient amplitude for three kinds of samples with different moisture content, within the probe at different insertion depths. We find that the conventional coaxial probe cannot distinguish small permittivity variations until the moisture content of materials reaches 3%. Meanwhile, the probe with the S-shaped structure can detect such small permittivity variations when the moisture content of samples changes by only 1%. The experimental results demonstrate that the new probe proposed in this paper is reliable and feasible.

  18. Stereoselective Access to Tubuphenylalanine and Tubuvaline: Improved Mn-Mediated Radical Additions and Assembly of A Tubulysin Tetrapeptide Analog

    PubMed Central

    Banerjee, Koushik; Marié, Jean-Charles; Mali, Umesh; Yao, Lei

    2016-01-01

    Synthesis of tubuphenylalanine and tubuvaline, α-substituted γ-amino acid building blocks for tubulysin family of antimitotic compounds, has been improved using a radical addition reaction in the presence of unprotected hydroxyl functionality. The key carbon–carbon bond construction entails stereoselective Mn-mediated photolytic additions of alkyl iodides to the C=N bond of chiral N-acylhydrazones, and generates the chiral amines in high yield with complete stereocontrol. Reductive N–N bond cleavage and alcohol oxidation converted these amino alcohols into the corresponding γ-amino acids. The route to tubuvaline proceeded via peptide coupling with serine methyl ester, followed by a high-yielding sequence to convert the serine amide to a thiazole. Finally, peptide bond construction established the tubulysin framework in the form of a C-terminal alcohol analog. Attempted oxidation to the C-terminal carboxylate was unsuccessful; control experiments with dipeptide 18 showed a cyclization interfered with the desired oxidation process. PMID:26883395

  19. Polyethylene glycol addition does not improve exogenous surfactant function in an experimental model of meconium aspiration syndrome.

    PubMed

    Lyra, Joao Cesar; Mascaretti, Renata Suman; Precioso, Alexander Roberto; Haddad, Luciana Branco; Mauad, Thais; Vaz, Flavio A Costa; Rebello, Celso Moura

    2009-02-01

    Meconium (MEC) is a potent inactivator of pulmonary surfactant. The authors studied the effects of polyethylene glycol addition to the exogenous surfactant over the lung mechanics and volumes. Human meconium was administrated to newborn rabbits. Animals were ventilated for 20 minutes and dynamic compliance, ventilatory pressure, and tidal volume were recorded. Animals were randomized into 3 study groups: MEC group (without surfactant therapy); S100 group (100 mg/kg surfactant); and PEG group (100 mg/kg porcine surfactant plus 5% PEG). After ventilation, a pulmonary pressure-volume curve was built. Histological analysis was carried out to calculate the mean alveolar size (Lm) and the distortion index (DI). Both groups treated with surfactant showed higher values of dynamic pulmonary compliance and lower ventilatory pressure, compared with the MEC group (P < .05). S100 group had a larger maximum lung volume, V(30), compared with the MEC group (P < .05). Lm and DI values were smaller in the groups treated with surfactant than in the MEC group (P < .05). No differences were observed between the S100 and PEG groups. Animals treated with surfactant showed significant improvement in pulmonary function as compared to nontreated animals. PEG added to exogenous surfactant did not improve lung mechanics or volumes.

  20. Potential of Lactobacillus reuteri from Spontaneous 
Sourdough as a Starter Additive for Improving Quality Parameters of Bread

    PubMed Central

    Vaičiulytė-Funk, Lina; Šalomskienė, Joana; Alenčikienė, Gitana; Mieželienė, Aldona

    2016-01-01

    Summary Retardation of microbial spoilage of bread can be achieved by the use of spontaneous sourdough with an antimicrobial activity. This study was undertaken to identify lactic acid bacteria naturally occurring in spontaneous sourdough and use them for quality improvement and prolonging shelf life of rye, wheat and rye with wheat bread. Identification of isolates from spontaneous sourdough by pyrosequencing assay showed that Lactobacillus reuteri were dominant lactic acid bacteria. The isolates showed a wide range of antimicrobial activity and displayed a synergistic activity against other lactobacilli, some lactococci and foodborne yeasts. The best application of spontaneous sourdough was noticed in the rye bread with the lowest crumb firmness of the final product, although the sensory results of wheat and rye with wheat bread did not statistically differ from control bread. L. reuteri showed a high preserving capacity against fungi during storage. This may be due to bacteriocins and various fatty acids secreted into the growth medium that were identified by agar well diffusion assay and gas chromatography. L. reuteri showing high antimicrobial activity have the potential to be used as a starter additive that could improve safety and/or shelf life of bread. PMID:27956866

  1. Community shifts of actively growing lake bacteria after N-acetyl-glucosamine addition: improving the BrdU-FACS method.

    PubMed

    Tada, Yuya; Grossart, Hans-Peter

    2014-02-01

    In aquatic environments, community dynamics of bacteria, especially actively growing bacteria (AGB), are tightly linked with dissolved organic matter (DOM) quantity and quality. We analyzed the community dynamics of DNA-synthesizing and accordingly AGB by linking an improved bromodeoxyuridine immunocytochemistry approach with fluorescence-activated cell sorting (BrdU-FACS). FACS-sorted cells of even oligotrophic ecosystems in winter were characterized by 16S rRNA gene analysis. In incubation experiments, we examined community shifts of AGB in response to the addition of N-acetyl-glucosamine (NAG), one of the most abundant aminosugars in aquatic systems. Our improved BrdU-FACS analysis revealed that AGB winter communities of oligotrophic Lake Stechlin (northeastern Germany) substantially differ from those of total bacteria and consist of Alpha-, Beta-, Gamma-, Deltaproteobacteria, Actinobacteria, Candidatus OP10 and Chloroflexi. AGB populations with different BrdU-fluorescence intensities and cell sizes represented different phylotypes suggesting that single-cell growth potential varies at the taxon level. NAG incubation experiments demonstrated that a variety of widespread taxa related to Alpha-, Beta-, Gammaproteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, Planctomycetes, Spirochaetes, Verrucomicrobia and Chloroflexi actively grow in the presence of NAG. The BrdU-FACS approach enables detailed phylogenetic studies of AGB and, thus, to identify those phylotypes which are potential key players in aquatic DOM cycling.

  2. Improving cyclic stability of lithium nickel manganese oxide cathode at elevated temperature by using dimethyl phenylphosphonite as electrolyte additive

    NASA Astrophysics Data System (ADS)

    Mai, Shaowei; Xu, Mengqing; Liao, Xiaolin; Xing, Lidan; Li, Weishan

    2015-01-01

    A novel electrolyte additive, dimethyl phenylphosphonite (DMPP), is reported in this paper to be able to improve significantly the cyclic stability of LiNi0.5Mn1.5O4 cathode of high voltage lithium ion battery at elevated temperature. When experiencing charge/discharge cycling at 50 °C with 1C (1C = 146.7 mAh g-1) rate in a standard (STD) electrolyte (1.0 M LiPF6 in ethylene carbonate (EC)/dimethyl carbonate (DMC), EC/DMC = 1/2 in volume), LiNi0.5Mn1.5O4 suffers serious discharge capacity decaying, with a capacity retention of 42% after 100 cycles. With adding 0.5% DMPP into the STD electrolyte, the capacity retention is increased to 91%. This improvement can be ascribed to the preferential oxidation of DMPP to the STD electrolyte and the subsequent formation of a protective film on LiNi0.5Mn1.5O4, which suppresses the electrolyte decomposition and protects LiNi0.5Mn1.5O4 from destruction. Theoretical calculations together with voltammetric analyses demonstrate the preferential oxidation of DMPP and the consequent suppression of electrolyte decomposition, while the observations from scanning electron microscopy, X-ray photoelectronic spectroscopy and Fourier transform infrared spectroscopy confirm the protection that DMPP provides for LiNi0.5Mn1.5O4.

  3. Randomized clinical trial assessing whether additional massage treatments for chronic neck pain improve 12- and 26-week outcomes

    PubMed Central

    Cook, Andrea J.; Wellman, Robert D.; Cherkin, Daniel C.; Kahn, Janet R.; Sherman, Karen J.

    2015-01-01

    Background Context This is the first study to systematically evaluate the value of a longer treatment period for massage. We provide a framework of how to conceptualize an optimal dose in this challenging setting of non-pharmacological treatments. Purpose To determine the optimal dose of massage for neck pain. Study Design/Setting Two-phase randomized trial for persons with chronic non-specific neck pain. Primary randomization to one of 5 groups receiving 4 weeks of massage (30 minutes 2×/ or 3×/week or 60 minutes 1×, 2×, or 3×/week). Booster randomization of participants to receive an additional 6 massages, 60 minute 1×/week, or no additional massage. Patient Sample 179 participants from Group Health and the general population of Seattle, WA USA recruited between June 2010 and August 2011. Outcome Measures Primary outcomes self-reported neck-related dysfunction (Neck Disability Index) and pain (0–10 scale) were assessed at baseline, 12, and 26 weeks. Clinically meaningful improvement was defined as >5 point decrease in dysfunction and > 30% decrease in pain from baseline. Methods Clinically meaningful improvement for each primary outcome with both follow-up times was analyzed using adjusted modified Poisson generalized estimating equations. Secondary analyses for the continuous outcomes used linear generalized estimating equations. This study was funded the National Center for Complementary and Alternative Medicine, NIH, USA (R01 AT004411). The funders had no role in the interpretation or reporting of results. Results There were no observed differences by primary treatment group at 12 or 26 weeks. Those receiving booster dose had improvements in both dysfunction and pain at 12 weeks (dysfunction: RR=1.56(1.08–2.25), P=0.018; pain: RR=1.25(0.98–1.61); P=0.077), but those were non-significant at 26 weeks (dysfunction: RR=1.22(0.85–1.74); pain: RR=1.09(0.82–1.43)). Subgroup analysis by primary and booster treatments found the booster dose only

  4. Assessing and improving the measuring capability of the Etna_NETVIS camera network for lava flow rapid mapping

    NASA Astrophysics Data System (ADS)

    Marsella, Maria; Junior Valentino D'Aranno, Peppe; Nardinocchi, Carla; Scifoni, Silvia; Scutti, Marianna; Sonnessa, Alberico; Biale, Emilio; Ciancitto, Francesco; Coltelli, Mauro; Pecora, Emilio; Prestifilippo, Michele; Proietti, Cristina

    2014-05-01

    This work is aimed at improving the performance of the ground NEtwork of Thermal and VIsible and cameras located on Mt. Etna volcano (Etna_NETVIS) by optimizing its observational capability on lava flows evolution and by developing dedicated tools for systematically measuring quantitative parameters of known accuracy. The first goal will be achieved through the analysis of the geometrical configuration and its improvement by means of the establishment of additional observation sites to be equipped with mobile stations, depending on the area of interest. This will increment the spatial coverage and improve the observation of the most active areas for surface sin-eruptive processes. For the second objective we will implement new processing tools to permit a reliable quantitative use of the data collected by the surveillance sensors of NETVIS, extending their capability in monitor the lava flow thermal and spatial evolution and by providing georeferenced data for rapid mapping scope. The tool will be used to automatically pre-process multitemporal datasets and will be tested on both simulated and real scenarios. Thanks to data collected and archive by the NETVIS INGV team, we will have the opportunity to develop and test the procedure in different operational conditions selected among the large number of lava flows coupled to lava fountan events occurred between 2011 and 2013. Additionally, Etna_NETVIS data can be used to downscale the information derived from satellite data and/or to integrate the satellite datasets in case of incomplete coverage or missing acquisitions (both due to low revisiting time or bad geometrical conditions). Therefore an additional goal is that of comparing/integrating quantitative data derived from visible and radar satellite sensors with the maps obtained using Etna_NETVIS. The procedure will take into account the discrepancy among the different datasets in terms of accuracy and resolution and will attempt to provide a combined approach

  5. Improved lattice Boltzmann modeling of binary flow based on the conservative Allen-Cahn equation

    NASA Astrophysics Data System (ADS)

    Ren, Feng; Song, Baowei; Sukop, Michael C.; Hu, Haibao

    2016-08-01

    The primary and key task of binary fluid flow modeling is to track the interface with good accuracy, which is usually challenging due to the sharp-interface limit and numerical dispersion. This article concentrates on further development of the conservative Allen-Cahn equation (ACE) [Geier et al., Phys. Rev. E 91, 063309 (2015), 10.1103/PhysRevE.91.063309] under the framework of the lattice Boltzmann method (LBM), with incorporation of the incompressible hydrodynamic equations [Liang et al., Phys. Rev. E 89, 053320 (2014), 10.1103/PhysRevE.89.053320]. Utilizing a modified equilibrium distribution function and an additional source term, this model is capable of correctly recovering the conservative ACE through the Chapman-Enskog analysis. We also simulate four phase-tracking benchmark cases, including one three-dimensional case; all show good accuracy as well as low numerical dispersion. By coupling the incompressible hydrodynamic equations, we also simulate layered Poiseuille flow and the Rayleigh-Taylor instability, illustrating satisfying performance in dealing with complex flow problems, e.g., high viscosity ratio, high density ratio, and high Reynolds number situations. The present work provides a reliable and efficient solution for binary flow modeling.

  6. Laser speckle contrast analysis (LASCA) for blood flow visualization: improved image processing

    NASA Astrophysics Data System (ADS)

    Briers, J. D.; He, Xiao-Wei

    1998-06-01

    LASCA is a single-exposure, full-field technique for mapping flow velocities. The motion of the particles in a fluid flow causes fluctuations in the speckle patten produced when laser light is scattered by the particles. The frequency of these intensity fluctuations increases with increasing velocity. These intensity fluctuations blur the speckle pattern and hence reduce its contrast. With a suitable integration time for the exposure, velocity can be mapped as speckle contrast. The equipment required is very simple. A CCD camera and a framegrabber capture an image of the area of interest. The local speckle contrast is computed and used to produce a false-color map of velocities. LASCA can be used to map capillary blood flow. The results are similar to those obtained by the scanning laser Doppler technique, but are obtained without the need to scan. This reduces the time needed for capturing the image from several minutes to a fraction of a second, already a clinical advantage. Until recently, however, processing the captured image did take several minutes. Improvements in the software have now reduced the processing tome to one second, thus providing a truly real-time method for obtaining a map of capillary blood flow.

  7. Multiplexed lateral flow biosensors: Technological advances for radically improving point-of-care diagnoses.

    PubMed

    Li, Jia; Macdonald, Joanne

    2016-09-15

    Lateral flow biosensors are a leading technology in point-of-care diagnostics due to their simplicity, rapidness and low cost. Their primacy in this arena continues through technological breakthroughs such as multiplexing: the detection of more than one biomarker in a single assay. Multiplexing capacity is critical for improving diagnostic efficiency, enhancing the diagnostic precision for specific diseases and reducing diagnostic cost. Here we review, for the first time, the various types and strategies employed for creating multiplexed lateral flow biosensors. These are classified into four main categories in terms of specific application or multiplexing level, namely linear, parameter, spatial and conceptual. We describe the practical applications and implications for each approach and compare their advantages and disadvantages. Importantly, multiplexing is still subject to limitations of the traditional lateral flow biosensor, such as sensitivity and specificity. However, by pushing the limitations of the traditional medium into the multiplex arena, several technological breakthroughs are emerging with novel solutions that further expand the utility of lateral flow biosensing for point-of-care applications.

  8. Critical transport issues for improving the performance of aqueous redox flow batteries

    NASA Astrophysics Data System (ADS)

    Zhou, X. L.; Zhao, T. S.; An, L.; Zeng, Y. K.; Wei, L.

    2017-01-01

    As the fraction of electricity generated from intermittent renewable sources (such as solar and wind) grows, developing reliable energy storage technologies to store electrical energy in large scale is of increasing importance. Redox flow batteries are now enjoying a renaissance and regarded as a leading technology in providing a well-balanced solution for current daunting challenges. In this article, state-of-the-art studies of the complex multicomponent transport phenomena in aqueous redox flow batteries, with a special emphasis on all-vanadium redox flow batteries, are reviewed and summarized. Rather than elaborating on the details of previous experimental and numerical investigations, this article highlights: i) the key transport issues in each battery's component that need to be tackled so that the rate capability and cycling stability of flow batteries can be significantly improved, ii) the basic mechanisms that control the active species/ion/electron transport behaviors in each battery's component, and iii) the key experimental and numerical findings regarding the correlations between the multicomponent transport processes and battery performance.

  9. Improving the early-warning of a mud-debris flow using radar rainfall data

    NASA Astrophysics Data System (ADS)

    Jun, Hwandon; Kim, Soojun; Lee, Jiho

    2016-04-01

    The timely and accurate warning of mud-debris flows including landslide hazards is very important to protect life and property. The rainfall estimation uncertainty makes it difficult to issue accurate warning. Traditionally rain gauges have been the main source of surface rainfall measurements. The rain gauges provide an accurate point rainfall estimates, but their spatial resolution is limited by the low-density of a gauge network. The errors associated with interpolation schemes to fill in the missing data over the ungauged sites can introduce significant error due to the long distance between the rain gauge stations and the hazard site (ungauged sites), particularly over rough terrain. The radar system can provide rainfall information at higher temporal and spatial resolutions than was previously possible from rain gauge measurements. While radar provides accurate spatial and temporal resolution of the rainfall field at significant heights above the surface of the earth, numerous measurement errors can result in an inaccurate rainfall depth at the ground. This study attempts to improve mud-debris flow early-warnings through accurate rainfall depth estimation by applying an innovative artificial neural network method. The first scenario uses the nearest rainfall observing site from an ungauged hazard site. The second uses the radar rainfall data and improves the rainfall estimation compared to the first scenario. The third scenario integrates the above two scenarios using both radar and observed rainfall at the sites around the ungauged hazard site, and improves the rainfall estimation by the largest margin. This methodology is applied to the Seoul metropolitan area. The proposed methodology can be applied to improve the confidence in the early-warning of the mud-debris flow hazard in other areas. Acknowledgment This research was supported by a grant (13SCIPS04) from Smart Civil Infrastructure Research Program funded by Ministry of Land, Infrastructure and

  10. Improving electricity production in tubular microbial fuel cells through optimizing the anolyte flow with spiral spacers.

    PubMed

    Zhang, Fei; Ge, Zheng; Grimaud, Julien; Hurst, Jim; He, Zhen

    2013-04-01

    The use of spiral spacers to create a helical flow for improving electricity generation in microbial fuel cells (MFCs) was investigated in both laboratory and on-site tests. The lab tests found that the MFC with the spiral spacers produced more electricity than the one without the spiral spacers at different recirculation rates or organic loading rates, likely due to the improved transport/distribution of ions and electron mediators instead of the substrates because the organic removal efficiency was not obviously affected by the presence of the spiral spacers. The energy production in the MFC with the spiral spacers reached 0.071 or 0.073 kWh/kg COD in either vertical or horizontal installment. The examination of the MFCs installed in an aeration tank of a municipal wastewater treatment plant confirmed the advantage of using the spiral spacers. Those results demonstrate that spiral spacers could be an effective approach to improve energy production in MFCs.

  11. An improved multi-value cellular automata model for heterogeneous bicycle traffic flow

    NASA Astrophysics Data System (ADS)

    Jin, Sheng; Qu, Xiaobo; Xu, Cheng; Ma, Dongfang; Wang, Dianhai

    2015-10-01

    This letter develops an improved multi-value cellular automata model for heterogeneous bicycle traffic flow taking the higher maximum speed of electric bicycles into consideration. The update rules of both regular and electric bicycles are improved, with maximum speeds of two and three cells per second respectively. Numerical simulation results for deterministic and stochastic cases are obtained. The fundamental diagrams and multiple states effects under different model parameters are analyzed and discussed. Field observations were made to calibrate the slowdown probabilities. The results imply that the improved extended Burgers cellular automata (IEBCA) model is more consistent with the field observations than previous models and greatly enhances the realism of the bicycle traffic model.

  12. Unmasking translucent protein particles by improved micro-flow imaging™ algorithms.

    PubMed

    Pedersen, Jesper Søndergaard; Persson, Malin

    2014-01-01

    Micro-flow imaging (MFI(™) ) is an increasingly important technique for the characterization of subvisible particles during the development of biopharmaceutical products. Protein particles are highly variable in size, appearance, and translucency posing challenges to optical detection techniques. We have developed a set of standard statistical tests applicable for routine evaluation of MFI™ particle dataset quality. The tests evaluate the spatial randomness of particles using nearest neighbor and quadrat analysis. Using case studies of stressed antibody samples, we demonstrate how the tests uncover fragmentation artifacts and uneven detector sensitivity for translucent particles. To improve the detection of translucent particles, a new local pixel intensity variance particle detection algorithm has been developed. The improved algorithm significantly decreases fragmentation artifacts, and also increases sensitivity toward translucent particles in general. Our results highlight current limitations and the potential for improvements in the optical detection techniques for subvisible protein aggregates.

  13. Does the Addition of a Duration Improve the Liso-Epeak Relation for Gamma-Ray Bursts?

    NASA Astrophysics Data System (ADS)

    Collazzi, Andrew C.; Schaefer, Bradley E.

    2008-11-01

    Firmani et al. proposed a new gamma ray burst (GRB) luminosity relation that showed a significant improvement over the Liso- Epeak relation (where Liso is the isotropic peak luminosity and Epeak is the photon energy of the spectral peak for the burst). The new proposed relation simply modifies the Epeak value by multiplying it by a power of T0.45, where T0.45 is a particular measure of the GRB duration. We begin by reproducing the results of Firmani for his 19 bursts. We then test the Firmani relation for the same 19 bursts, except that we use independently measured values for Liso, T0.45, and Epeak, and we find that the relation deteriorates substantially. We further test the relation by using 60 GRBs with measured spectroscopic redshifts, and find a relation that has a comparable scatter as the original L iso-Epeak relation. That is, a much larger sample of bursts does not reproduce the small scatter as reported by Firmani et al. Finally, we investigate whether the Firmani relation is improved by the use of any of 32 measures of duration (e.g., T90, T50, T90/Npeak, the fluence divided by the peak flux, T0.30, and T0.60) in place of T0.45. The quality of each alternative duration measure is evaluated with the root mean square of the scatter between the observed and fitted logarithmic Liso values. Although we find that some durations yield slightly better results than T0.45, the differences between the duration measures are minimal. We find that the addition of a duration does not add any significant improvement to the Liso- Epeak relation. We also present a simple and direct derivation of the Firmani relation from both the Liso-Epeak and Amati relations. In all, we conclude that the Firmani relation neither has an independent existence nor does it provide any significant improvement on previously known relations that are simpler.

  14. Improved turbulence models based on large eddy simulation of homogeneous, incompressible turbulent flows

    NASA Technical Reports Server (NTRS)

    Bardino, J.; Ferziger, J. H.; Reynolds, W. C.

    1983-01-01

    The physical bases of large eddy simulation and subgrid modeling are studied. A subgrid scale similarity model is developed that can account for system rotation. Large eddy simulations of homogeneous shear flows with system rotation were carried out. Apparently contradictory experimental results were explained. The main effect of rotation is to increase the transverse length scales in the rotation direction, and thereby decrease the rates of dissipation. Experimental results are shown to be affected by conditions at the turbulence producing grid, which make the initial states a function of the rotation rate. A two equation model is proposed that accounts for effects of rotation and shows good agreement with experimental results. In addition, a Reynolds stress model is developed that represents the turbulence structure of homogeneous shear flows very well and can account also for the effects of system rotation.

  15. The effectiveness of a provider in triage in the emergency department: a quality improvement initiative to improve patient flow.

    PubMed

    Love, Robert A; Murphy, John A; Lietz, Timothy E; Jordan, Kathleen S

    2012-01-01

    Hospital emergency departments (EDs) throughout the United States are faced with overwhelming challenges due to the high demand for services, an increasing number of visits, overuse and misuse of services, and escalating healthcare costs. The result of this situation is that EDs are overcrowded, patients are experiencing long wait times, ambulances are being diverted, admitted patients are being boarded, and patients in need of emergency medical care are leaving without treatment. The purpose of this article is to present a quality improvement initiative designed and implemented to improve patient flow through an ED by redesigning the triage process to increase the efficiency and timeliness of initial patient contact with a licensed medical provider, increasing patient satisfaction, and decreasing the number of patients who leave without being seen. To accomplish these goals, a nurse practitioner/physician assistant medical provider was reallocated to the triage area to perform an initial assessment and initiate diagnostic studies. The results of this initiative have proven to be positive in goal attainment. The time from patient arrival to initial contact with a licensed medical provider has decreased from 75 to 25 min. The percentage of patients who leave without being seen has decreased from 3.6% to 0.9%.

  16. Improved numerical modeling of groundwater flow and transport at the MADE-2 site. Final report

    SciTech Connect

    Gray, D.D.; Rucker, D.F.

    1995-02-01

    Public domain computer programs were used to attempt an improved model of the tritium plume observed during Macrodispersion Experiment 2 (MADE-2), a field scale natural gradient experiment conducted at Columbus Air Force Base, Mississippi. The finite difference program MODFLOW was used to simulate the flow of groundwater through a 330 m x 105 m computational domain. Solutions for the 468 day experiment were obtained using a Sun Sparcstation 2 for several choices of convergence and storage parameters. The simulations had small mass balance errors and were consistent with continuous head observations. Tritium plume simulations used the mixed Lagrangian-Eulerian finite difference program MT3D to solve the contaminant transport equation using the MODFLOW-predicted flow field. Thirteen runs were made using various advection algorithms and dispersivities, but none was successful.

  17. An Improved Treatment of External Boundary for Three-Dimensional Flow Computations

    NASA Technical Reports Server (NTRS)

    Tsynkov, Semyon V.; Vatsa, Veer N.

    1997-01-01

    We present an innovative numerical approach for setting highly accurate nonlocal boundary conditions at the external computational boundaries when calculating three-dimensional compressible viscous flows over finite bodies. The approach is based on application of the difference potentials method by V. S. Ryaben'kii and extends our previous technique developed for the two-dimensional case. The new boundary conditions methodology has been successfully combined with the NASA-developed code TLNS3D and used for the analysis of wing-shaped configurations in subsonic and transonic flow regimes. As demonstrated by the computational experiments, the improved external boundary conditions allow one to greatly reduce the size of the computational domain while still maintaining high accuracy of the numerical solution. Moreover, they may provide for a noticeable speedup of convergence of the multigrid iterations.

  18. Availability Improvement of Layer 2 Seamless Networks Using OpenFlow

    PubMed Central

    Molina, Elias; Jacob, Eduardo; Matias, Jon; Moreira, Naiara; Astarloa, Armando

    2015-01-01

    The network robustness and reliability are strongly influenced by the implementation of redundancy and its ability of reacting to changes. In situations where packet loss or maximum latency requirements are critical, replication of resources and information may become the optimal technique. To this end, the IEC 62439-3 Parallel Redundancy Protocol (PRP) provides seamless recovery in layer 2 networks by delegating the redundancy management to the end-nodes. In this paper, we present a combination of the Software-Defined Networking (SDN) approach and PRP topologies to establish a higher level of redundancy and thereby, through several active paths provisioned via the OpenFlow protocol, the global reliability is increased, as well as data flows are managed efficiently. Hence, the experiments with multiple failure scenarios, which have been run over the Mininet network emulator, show the improvement in the availability and responsiveness over other traditional technologies based on a single active path. PMID:25759861

  19. An improved method for calculating flow past flapping and hovering airfoils

    NASA Astrophysics Data System (ADS)

    Sengupta, T. K.; Vikas, V.; Johri, A.

    2005-12-01

    A method is reported here for calculating unsteady aerodynamics of hovering and flapping airfoil for two-dimensional flow via the following improved methodologies: (a) a correct formulation of the problem using stream function (ψ) and vorticity (ω) as dependent variables; (b) calculating loads and moment by a new method to solve the governing pressure Poisson equation (PPE) in a truncated part of the computational domain on a nonstaggered grid; (c) accurate solution using high accuracy compact difference scheme for the vorticity transport equation (VTE) and (d) accelerating the computations by using a high-order filter after each time step of integration. These have been used to solve Navier-Stokes equation for flow past flapping and hovering NACA 0014 and 0015 airfoils at typical Reynolds numbers relevant to the study of unsteady aerodynamics of micro air vehicle (MAV) and insect/bird flight.

  20. Pair collisions of fluid-filled elastic capsules in shear flow: Effects of membrane properties and polymer additives

    NASA Astrophysics Data System (ADS)

    Pranay, Pratik; Anekal, Samartha G.; Hernandez-Ortiz, Juan P.; Graham, Michael D.

    2010-12-01

    The dynamics and pair collisions of fluid-filled elastic capsules during Couette flow in Newtonian fluids and dilute solutions of high-molecular weight (drag-reducing) polymers are investigated via direct simulation. Capsule membranes are modeled using either a neo-Hookean constitutive model or a model introduced by Skalak et al. ["Strain energy function of red blood-cell membranes," Biophys. J. 13, 245 (1973)], which includes an energy penalty for area changes. This model was developed to capture the elastic properties of red blood cells. Polymer molecules are modeled as bead-spring trimers with finitely extensible nonlinearly elastic springs; parameters were chosen to loosely approximate 4000 kDa poly(ethylene oxide). Simulations are performed with a novel Stokes flow formulation of the immersed boundary method for the capsules, combined with Brownian dynamics for the polymer molecules. The results for isolated capsules in shear indicate that at the very low concentrations considered here, polymers have a little effect on the capsule shape. In the case of pair collisions, the effect of polymer is strongly dependent on the elastic properties of the capsules' membranes. For neo-Hookean capsules or for Skalak capsules with only a small penalty for area change, the net displacement in the gradient direction after collision is virtually unaffected by the polymer. For Skalak capsules with a large penalty for area change, polymers substantially decrease the net displacement when compared to the Newtonian case and the effect is enhanced upon increasing the polymer concentration. The differences between the polymer effects in the various cases are associated with the extensional flow generated in the region between the capsules as they leave the collision. The extension rate is highest when there is a strong resistance to a change in the membrane area and is substantially decreased in the presence of polymer.

  1. Addition of fentanyl to the ultrasound-guided transversus abdominis plane block does not improve analgesia following cesarean delivery

    PubMed Central

    WANG, LI-ZHONG; LIU, XIA; ZHANG, YING-FA; HU, XIAO-XIA; ZHANG, XIAO-MING

    2016-01-01

    The present study aimed to investigate whether the addition of fentanyl to the transversus abdominis plane (TAP) block procedure may improve analgesic duration following cesarean delivery. A total of 147 nulliparous women with an American Society of Anesthesiologists physical status I–II, scheduled for elective cesarean delivery under spinal anesthesia, were enrolled in the present study. All patients underwent cesarean delivery under spinal anesthesia with 10 mg bupivacaine and 10 µg fentanyl, after which the patients underwent an ultrasound-guided bilateral TAP block with either 0.375% ropivacaine (group TR; n=48), 0.375% ropivacaine and 50 µg subcutaneous fentanyl (group TRSF; n=49), or a mixture of 0.375% ropivacaine and 50 µg fentanyl (2.5 µg/ml; group TRF; n=50) per side. The TAP block formed part of a multimodal analgesic regimen comprising patient-controlled analgesia (PCA) with intravenous fentanyl, and regular treatment with diclofenac and paracetamol. The TAP block was performed in the midaxillary line using an in-plane technique. The primary outcome was the time to the first PCA, whereas secondary outcomes were the cumulative and interval PCA consumptions, visual analogue scale (VAS) pain scores at rest and during movement, side effects assessed at 2, 6, 12, 24 and 48 h postoperatively, and patient satisfaction with postoperative analgesia. No significant differences were observed in the median time to the first PCA among the three groups (P=0.640), which were 150 min (70–720 min) in group TR, 165 min (90–670 min) in group TRSF, and 190 min (70–680 min) in group TRF. Fentanyl consumption, VAS pain scores, side effects and patient satisfaction were similar among the three groups; however, the demand for fentanyl was significantly decreased in the TRSF and TRF groups at 2 h postoperatively (P=0.001 and 0.002, respectively), as compared with group TR. No complications attributed to the TAP block were detected. In conclusion, the results of the

  2. Flow cytometry as an improved method for the titration of Chlamydiaceae and other intracellular bacteria.

    PubMed

    Käser, T; Pasternak, J A; Hamonic, G; Rieder, M; Lai, K; Delgado-Ortega, M; Gerdts, V; Meurens, F

    2016-05-01

    Chlamydiaceae is a family of intracellular bacteria causing a range of diverse pathological outcomes. The most devastating human diseases are ocular infections with C. trachomatis leading to blindness and genital infections causing pelvic inflammatory disease with long-term sequelae including infertility and chronic pelvic pain. In order to enable the comparison of experiments between laboratories investigating host-chlamydia interactions, the infectious titer has to be determined. Titer determination of chlamydia is most commonly performed via microscopy of host cells infected with a serial dilution of chlamydia. However, other methods including fluorescent ELISpot (Fluorospot) and DNA Chip Scanning Technology have also been proposed to enumerate chlamydia-infected cells. For viruses, flow cytometry has been suggested as a superior alternative to standard titration methods. In this study we compared the use of flow cytometry with microscopy and Fluorospot for the titration of C. suis as a representative of other intracellular bacteria. Titer determination via Fluorospot was unreliable, while titration via microscopy led to a linear read-out range of 16 - 64 dilutions and moderate reproducibility with acceptable standard deviations within and between investigators. In contrast, flow cytometry had a vast linear read-out range of 1,024 dilutions and the lowest standard deviations given a basic training in these methods. In addition, flow cytometry was faster and material costs were lower compared to microscopy. Flow cytometry offers a fast, cheap, precise, and reproducible alternative for the titration of intracellular bacteria like C. suis. © 2016 International Society for Advancement of Cytometry.

  3. Improving gelation efficiency and cytocompatibility of visible light polymerized thiol-norbornene hydrogels via addition of soluble tyrosine.

    PubMed

    Shih, Han; Liu, Hung-Yi; Lin, Chien-Chi

    2017-02-28

    Hydrogels immobilized with biomimetic peptides have been used widely for tissue engineering and drug delivery applications. Photopolymerization has been among the most commonly used techniques to fabricate peptide-immobilized hydrogels as it offers rapid and robust peptide immobilization within a crosslinked hydrogel network. Both chain-growth and step-growth photopolymerizations can be used to immobilize peptides within covalently crosslinked hydrogels. A previously developed visible light mediated step-growth thiol-norbornene gelation scheme has demonstrated efficient crosslinking of hydrogels composed of an inert poly(ethylene glycol)-norbornene (PEGNB) macromer and a small molecular weight bis-thiol linker, such as dithiothreitol (DTT). Compared with conventional visible light mediated chain-polymerizations where multiple initiator components are required, step-growth photopolymerized thiol-norbornene hydrogels are more cytocompatible for the in situ encapsulation of radical sensitive cells (e.g., pancreatic β-cells). This contribution explored visible light based crosslinking of various bis-cysteine containing peptides with macromer 8-arm PEGNB to form biomimetic hydrogels suitable for in situ cell encapsulation. It was found that the addition of soluble tyrosine during polymerization not only significantly accelerated gelation, but also improved the crosslinking efficiency of PEG-peptide hydrogels as evidenced by a decreased gel point and enhanced gel modulus. In addition, soluble tyrosine drastically enhanced the cytocompatibility of the resulting PEG-peptide hydrogels, as demonstrated by in situ encapsulation and culture of pancreatic MIN6 β-cells. This visible light based thiol-norbornene crosslinking mechanism provides an attractive gelation method for preparing cytocompatible PEG-peptide hydrogels for tissue engineering applications.

  4. Reduced glutathione addition improves both the kinematics and physiological quality of post-thawed red deer sperm.

    PubMed

    Anel-López, L; Garcia-Alvarez, O; Maroto-Morales, A; Iniesta-Cuerda, M; Ramón, M; Soler, A J; Fernández-Santos, M R; Garde, J J

    2015-11-01

    The potential protective effect of reduced glutathione (GSH) and trolox (TRX), an analogue of vitamin E, supplementation during in vitro culture (2h, 39°C) of electroejaculated frozen/thawed red deer sperm was investigated. Cryopreserved sperm were thawed and incubated with no additive (Control) and 1mM or 5mM of each antioxidant to find out whether these supplementations can maintain the sperm quality, considering the use of thawed samples for in vitro techniques such as in vitro fertilisation (IVF), sperm sex sorting or refreezing. The effect of GSH on sperm motility was positive compared to TRX which was negative (P<0.001). After 2h of incubation at 39°C, use of GSH improved motility while TRX supplementation reduced sperm motility compared with Control samples without antioxidant. Use of TRX at both concentrations (1 and 5mM; TRX1 and TRX5) resulted in lesser percentages of apoptotic sperm (12.4±1.1% and 11.7±0.9%) than GSH1, GSH5 (15.2±1% and 14.6±1.1%) and Control samples (16.9±1.2%) (P<0.001). Use of GSH at both concentrations (1 and 5mM) resulted in greater mitochondrial activity as compared with findings for the Control, TRX1 and TRX5 groups. Results of this study indicate that GSH is a suitable supplement for electroejaculated red deer sperm. It would be necessary to conduct fertility trials (in vivo and in vitro), to assess whether GSH supplementation of thawed red deer sperm could improve fertility rates.

  5. Refinement of Fread s Method for improved tracking of stream discharges during unsteady flows

    DOE PAGES

    Lee, Kyutae; Muste, Marian

    2017-02-07

    There are a plethora of analytical approaches to account for the effect of unsteady flow (a.k.a. hysteretic behavior) on the conventionally-built steady rating curves (RCs) used to continuously estimate discharges in open channel flow. One of the most complete correction methods is Fread s method (Fread, 1975) which is based on fully dynamic one-dimensional wave equation. Proposed herein is a modified Fread s method which is adjusted to account for the actual geometry of the cross section. This method improves the accuracy associated with the estimation of conveyance factor and energy slope, so it is particularly useful for small tomore » mid-size streams/rivers where the original method s assumption does not properly hold. The modified Fread s method is tested for the sites in Clear Creek (Iowa, USA) and Ebro River (Spain) to illustrate the significance of its improvement in discharge estimation. While the degree of improvement is apparent for the conveyance factor because the hydraulic depth is replaced by hydraulic radius, that for the energy slope term specifically depends on the site and event conditions.« less

  6. Food additives

    MedlinePlus

    ... or natural. Natural food additives include: Herbs or spices to add flavor to foods Vinegar for pickling ... Certain colors improve the appearance of foods. Many spices, as well as natural and man-made flavors, ...

  7. Effect of Steam Addition on the Flow Field and NOx Emissions for Jet-A in an Aircraft Combustor

    NASA Astrophysics Data System (ADS)

    Xue, Rui; Hu, Chunbo; Nikolaidis, Theoklis; Pilidis, Pericle

    2016-12-01

    The steam injection technology for aircraft engines is gaining rising importance because of the strong limitations imposed by the legislation for NOx reduction in airports. In order to investigate the impact of steam addition on combustion and NOx emissions, an integrated performance-CFD-chemical reactor network (CRN) methodology was developed. The CFD results showed steam addition reduced the high temperature size and the radical pool moved downstream. Then different post-processing techniques are employed and CRN is generated to predict NOx emissions. This network consists of 14 chemical reactor elements and the results were in close agreement with the ICAO databank. The established CRN model was then used for steam addition study and the results showed under air/steam mixture atmosphere, high steam content could push the NOx formation region to the post-flame zone and a large amount of the NOx emission could be reduced when the steam mass fraction is quite high.

  8. An artificial intelligence based improved classification of two-phase flow patterns with feature extracted from acquired images.

    PubMed

    Shanthi, C; Pappa, N

    2017-02-13

    Flow pattern recognition is necessary to select design equations for finding operating details of the process and to perform computational simulations. Visual image processing can be used to automate the interpretation of patterns in two-phase flow. In this paper, an attempt has been made to improve the classification accuracy of the flow pattern of gas/ liquid two- phase flow using fuzzy logic and Support Vector Machine (SVM) with Principal Component Analysis (PCA). The videos of six different types of flow patterns namely, annular flow, bubble flow, churn flow, plug flow, slug flow and stratified flow are recorded for a period and converted to 2D images for processing. The textural and shape features extracted using image processing are applied as inputs to various classification schemes namely fuzzy logic, SVM and SVM with PCA in order to identify the type of flow pattern. The results obtained are compared and it is observed that SVM with features reduced using PCA gives the better classification accuracy and computationally less intensive than other two existing schemes. This study results cover industrial application needs including oil and gas and any other gas-liquid two-phase flows.

  9. Aripiprazole Improves Associated Comorbid Conditions in Addition to Tics in Adult Patients with Gilles de la Tourette Syndrome.

    PubMed

    Gerasch, Sarah; Kanaan, Ahmad Seif; Jakubovski, Ewgeni; Müller-Vahl, Kirsten R

    2016-01-01

    Gilles de la Tourette Syndrome (GTS) is characterized by motor and vocal tics, as well as associated comorbid conditions including obsessive-compulsive disorder (OCD), attention deficit/hyperactivity disorder (ADHD), depression, and anxiety which are present in a substantial number of patients. Although randomized controlled trials including a large number of patients are still missing, aripiprazole is currently considered as a first choice drug for the treatment of tics. The aim of this study was to further investigate efficacy and safety of aripiprazole in a group of drug-free, adult patients. Specifically, we investigated the influence of aripiprazole on tic severity, comorbidities, premonitory urge (PU), and quality of life (QoL). Moreover, we were interested in the factors that influence a patient's decision in electing for-or against- pharmacological treatment. In this prospective uncontrolled open-label study, we included 44 patients and used a number of rating scales to assess tic severity, PU, comorbidities, and QoL at baseline and during treatment with aripiprazole. Eighteen out of fortyfour patients decided for undergoing treatment for their tics with aripiprazole and completed follow-up assessments after 4-6 weeks. Our major findings were (1) aripiprazole resulted in significant reduction of tics, but did not affect PU; (2) aripiprazole significantly improved OCD and showed a trend toward improvement of other comorbidities including depression, anxiety, and ADHD; (3) neither severity of tics, nor PU or QoL influenced patients' decisions for or against treatment of tics with aripiprazole; instead patients with comorbid OCD tended to decide in favor of, while patients with comorbid ADHD tended to decide against tic treatment; (4) most frequently reported adverse effects were sleeping problems; (5) patients' QoL was mostly impaired by comorbid depression. Our results suggest that aripiprazole may improve associated comorbid conditions in addition to tics

  10. Aripiprazole Improves Associated Comorbid Conditions in Addition to Tics in Adult Patients with Gilles de la Tourette Syndrome

    PubMed Central

    Gerasch, Sarah; Kanaan, Ahmad Seif; Jakubovski, Ewgeni; Müller-Vahl, Kirsten R.

    2016-01-01

    Gilles de la Tourette Syndrome (GTS) is characterized by motor and vocal tics, as well as associated comorbid conditions including obsessive-compulsive disorder (OCD), attention deficit/hyperactivity disorder (ADHD), depression, and anxiety which are present in a substantial number of patients. Although randomized controlled trials including a large number of patients are still missing, aripiprazole is currently considered as a first choice drug for the treatment of tics. The aim of this study was to further investigate efficacy and safety of aripiprazole in a group of drug-free, adult patients. Specifically, we investigated the influence of aripiprazole on tic severity, comorbidities, premonitory urge (PU), and quality of life (QoL). Moreover, we were interested in the factors that influence a patient's decision in electing for-or against- pharmacological treatment. In this prospective uncontrolled open-label study, we included 44 patients and used a number of rating scales to assess tic severity, PU, comorbidities, and QoL at baseline and during treatment with aripiprazole. Eighteen out of fortyfour patients decided for undergoing treatment for their tics with aripiprazole and completed follow-up assessments after 4–6 weeks. Our major findings were (1) aripiprazole resulted in significant reduction of tics, but did not affect PU; (2) aripiprazole significantly improved OCD and showed a trend toward improvement of other comorbidities including depression, anxiety, and ADHD; (3) neither severity of tics, nor PU or QoL influenced patients' decisions for or against treatment of tics with aripiprazole; instead patients with comorbid OCD tended to decide in favor of, while patients with comorbid ADHD tended to decide against tic treatment; (4) most frequently reported adverse effects were sleeping problems; (5) patients' QoL was mostly impaired by comorbid depression. Our results suggest that aripiprazole may improve associated comorbid conditions in addition to tics

  11. Improving segmentation of 3D touching cell nuclei using flow tracking on surface meshes.

    PubMed

    Li, Gang; Guo, Lei

    2012-01-01

    Automatic segmentation of touching cell nuclei in 3D microscopy images is of great importance in bioimage informatics and computational biology. This paper presents a novel method for improving 3D touching cell nuclei segmentation. Given binary touching nuclei by the method in Li et al. (2007), our method herein consists of several steps: surface mesh reconstruction and curvature information estimation; direction field diffusion on surface meshes; flow tracking on surface meshes; and projection of surface mesh segmentation to volumetric images. The method is validated on both synthesised and real 3D touching cell nuclei images, demonstrating its validity and effectiveness.

  12. Explicit Runge-Kutta schemes for incompressible flow with improved energy-conservation properties

    NASA Astrophysics Data System (ADS)

    Capuano, F.; Coppola, G.; Rández, L.; de Luca, L.

    2017-01-01

    The application of pseudo-symplectic Runge-Kutta methods to the incompressible Navier-Stokes equations is discussed in this work. In contrast to fully energy-conserving, implicit methods, these are explicit schemes of order p that preserve kinetic energy to order q, with q > p. Use of explicit methods with improved energy-conservation properties is appealing for convection-dominated problems, especially in case of direct and large-eddy simulation of turbulent flows. A number of pseudo-symplectic methods are constructed for application to the incompressible Navier-Stokes equations and compared in terms of accuracy and efficiency by means of numerical simulations.

  13. Improvement of bioactivity, degradability, and cytocompatibility of biocement by addition of mesoporous magnesium silicate into sodium-magnesium phosphate cement.

    PubMed

    Wu, Yingyang; Tang, Xiaofeng; Chen, Jie; Tang, Tingting; Guo, Han; Tang, Songchao; Zhao, Liming; Ma, Xuhui; Hong, Hua; Wei, Jie

    2015-09-01

    A novel mesoporous magnesium-based cement (MBC) was fabricated by using the mixed powders of magnesium oxide, sodium dihydrogen phosphate, and mesoporous magnesium silicate (m-MS). The results indicate that the setting time and water absorption of the MBC increased as a function of increasing m-MS content, while compressive strength decreased. In addition, the degradability of the MBC in a solution of Tris-HCl and the ability of apatite formation on the MBC were significantly improved with the increase in m-MS content. In cell culture experiments, the results show that the attachment, proliferation, and alkaline phosphatase activity of the MC3T3-E1 cells on the MBC were significantly enhanced with the increase of the content of m-MS. It can be suggested that the MBC with good cytocompatibility could promote the proliferation and differentiation of the MC3T3-E1 cells. In short, our findings indicate that the MBC containing m-MS had promising potential as a new biocement for bone regeneration and repair applications.

  14. Additive effects on the improvement of insecticidal activity: Design, synthesis, and insecticidal activity of novel pymetrozine derivatives.

    PubMed

    Yang, Yan; Liu, Yuxiu; Song, Hongjian; Li, Yongqiang; Wang, Qingmin

    2016-02-01

    A series of new pymetrozine analogues containing both methyl on the imine carbon and phenoxy group at the pyridine ring were designed and synthesized. Their insecticidal activities against bean aphid (Aphis craccivora), mosquito larvae (Culex pipiens pallens), cotton bollworm (Helicoverpa armigera), corn borer (Ostrinia nubilalis) and oriental armyworm (Mythimna separata) were evaluated. The results of bioassays indicated that most of the target compounds showed good insecticidal activity against bean aphid; especially, IIIf (80%) and IIIl (80%) exhibited higher aphicidal activity than pymetrozine (30%) at 5mg/kg, and the two compounds still showed 20% and 30% mortality at 2.5mg/kg, respectively, whereas pymetrozine displayed no activity at the same concentration. These compounds exhibited a completely different structure-activity relationship to that of known pymetrozine derivatives, in which it is thought introducing alkyl group on the imine carbon could be detrimental to the activities. Our new result suggested that the methyl on the imine carbon and phenoxy group at the pyridine ring of phenoxy group may play additive effects on the improvement of aphicidal activity. Besides this, compound IIIs, containing an allyl at the para position of phenoxy group, exhibited excellent insecticidal activity against mosquito larvae, lepidoptera pests cotton bollworm, corn borer and oriental armyworm.

  15. Did the addition of concomitant chemotherapy to radiotherapy improve outcomes in hypopharyngeal cancer? A population-based study

    PubMed Central

    Hall, S.F.; Griffiths, R.

    2016-01-01

    Background For oncologists and for patients, no site-specific clinical trial evidence has emerged for the use of concurrent chemotherapy with radiotherapy (ccrt) over radiotherapy (rt) alone for cancer of the hypopharynx (hpc) or for other human papilloma virus–negative head-and-neck cancers. Methods This retrospective population-based cohort study using administrative data compared treatments over time (1990–2000 vs. 2000–2010), treatment outcomes, and outcomes over time in 1333 cases of hpc diagnosed in Ontario between January 1990 and December 2010. Results The incidence of hpc is declining; the use of ccrt that began in 2001 is increasing; and the 3-year overall survival for all patients remains poor at 34.6%. No difference in overall survival was observed in a comparison of patients treated in the decade before ccrt and of patients treated in the decade during the uptake of ccrt. Conclusions The addition of ccrt to the armamentarium of treatment options for oncologists treating head-and-neck patients did not improve outcomes for hpc at the population level. PMID:27536177

  16. An evaluation of EDTA additions for improving the phytoremediation efficiency of different plants under various cultivation systems.

    PubMed

    Luo, Jie; Qi, Shihua; Gu, X W Sophie; Wang, Jinji; Xie, Xianming

    2016-05-01

    Previous studies have shown that phytoremediation usually requires soil amendments, such as chelates, to mobilize low bioavailability heavy metals for better plant absorption and, consequently, for remediation efficiency. A total dry biomass of 3.39 and 0.0138 kg per plant was produced by a phytoremediator, Eucalyptus globulus, and a nitrogen fixing crop, Cicer arietinum (chickpea), respectively. The accumulation of Pb in E. globulus and chickpea reached 1170.61 and 1.33 mg per plant (700 and 324 mg kg(-1)), respectively, under an ethylene diamine tetraacetic acid (EDTA) treatment, which was a five and sixfold increase over the value in untreated experiments, respectively. EDTA enhanced the phytoremediation efficiency and increased the heavy metal concentration in the soil solution. In pot experiments, approximately 27 % of the initial Pb leached from the spiked soil after EDTA and 25 mm artificial precipitation additions into soil without plants, which was considerably larger than the value under the same conditions without EDTA application (7 %). E. globulus planted in a mixed culture had higher water use efficiency than monocultures of either species in field experiments, and E. globulus intercepted almost all of the artificial precipitation in the pot experiments. This study demonstrates that E. globulus can maximize the potential of EDTA for improving the phytoremediation efficiency and minimizing its negative effects to the environment simultaneously by absorbing the metal-rich leachate, especially in a mixed culture of E. globulus and chickpeas.

  17. Improvement of low bioavailability of a novel factor Xa inhibitor through formulation of cationic additives in its oral dosage form.

    PubMed

    Fujii, Yoshimine; Kanamaru, Taro; Kikuchi, Hiroshi; Nakagami, Hiroaki; Yamashita, Shinji; Akashi, Mitsuru; Sakuma, Shinji

    2011-12-15

    A clinical trial of (2S)-2-[4-[[(3S)-1-acetimidoyl-3-pyrrolidinyl]oxy]phenyl]-3-(7-amidino-2-naphtyl) propanoic acid (DX-9065) revealed that its oral bioavailability was only 3% when it was administered as a conventional capsule formulation. The low bioavailability of DX-9065 was likely caused by both its poor membrane permeability and its electrostatic interaction with anionic bile acids. We hypothesized that DX-9065 absorption would be enhanced when the cationic drug was free from the complex through its replacement with other cationic substances. Polystyrene nanospheres coated with cationic poly(vinylamine) and cholestyramine, which is clinically used as a cholesterol-lowering agent, dramatically prevented DX-9065 from interacting with chenodeoxycholic acid in vitro. Successive animal experiments showed that bioavailability of DX-9065 administered with these cationic substances was 2-3 times that of DX-9065 administered solely. A dry syrup formulation with one-half of a minimal cholesterol-lowering equivalent dose of cholestyramine was designed, and the clinical trial was resumed. A 1.3-fold increase in bioavailability of DX-9065 was observed when the dry syrup was administered. We successfully demonstrated that DX-9065 absorption was enhanced when the drug was administered with cationic additives; however, it appeared that the absorption-enhancing function of cholestyramine largely depended on its dose. The dose escalation is probably prerequisite for the significant improvement of DX-9065 absorption in humans.

  18. Improving the Compatibility of Donor Polymers in Efficient Ternary Organic Solar Cells via Post-Additive Soaking Treatment.

    PubMed

    Yang, Xiaoyu; Zheng, Fei; Xu, Weilong; Bi, Pengqing; Feng, Lin; Liu, Jianqiang; Hao, Xiaotao

    2017-01-11

    In dual-donor ternary organic solar cells, the compatibility between the donor polymers plays important roles to control the conformational change and govern the photophysical behavior in the blend films. Here, we apply a post-additive soaking (PAS) approach to reconstruct the morphology in a ternary organic photovoltaic BHJ of PTB7-Th: PCDTBT: PC71BM. The PAS-treated device has a maximum power conversion efficiency (PCE) of about 8.7% in this ternary system. From the analyses of GIWAXS and GISAXS, the superior device performance is attributed to the favorable nanomorphology with optimum crystallinity of PTB7-Th and good intermixing of PCDTBT with PTB7-Th:PC71BM, leading to improved charge transport in the vertical direction. AFM and TRPL measurements clearly demonstrate PAS-treated film envisages a homogeneous distribution of smaller PC71BM aggregates to facilitate the exciton dissociation and carrier extraction at the interface. The increased PCE ascribed to not only the enhancement of absorption and nonradiative Förster resonance energy transfer (FRET) between two donors (PCDTBT and PTB7-Th) but also the formation of a bicontinuous interpenetrating network of PC71BM.

  19. Improving Landslide Inventories by Limiting Land Classification to Drainage Areas of Debris Flow-Dominated Channels

    NASA Astrophysics Data System (ADS)

    Lyons, N. J.; Mitasova, H.; Wegmann, K. W.

    2011-12-01

    Landslide inventories, frequently created by aerial photograph interpretation (API), are often used in the production of hillslope hazard maps to characterize past landslides or to evaluate a hazard model. In the former application of inventories, potential landslides in hazard maps are delineated as areas that have similar morphometrics as past landslides at locations of modeled hillslope instability. Therefore, the accuracy of the inventory has a strong influence upon hazard extent. In the latter application, the partial inventories that sometimes result from API, due to the subjectivity of interpretation and revegetation of landslides, likely results in incorrect evaluations. A more complete, less subjective technique is needed to not only better characterize past landslides and improve evaluation of hazard models, but also to assess the extent of areas prone to significant mass wasting in mountainous regions due to the evolution of landscapes. Inventory accuracy continues to improve with new technology and automated techniques, though rarely is the form of a channel's topography incorporated into the inventory process despite the growing evidence of a topographic signature of debris flows. This signature demarcates the transition between the dominant channel erosional process: fluvial or debris flow. These process transitions are often observed at scaling breaks in log-log plots of a channel's drainage area versus slope (DS plot). The scaling breaks, above which the effects of fluvial power laws upon channel topography are not observed and below which debris flow scars are not found, may signify the lowest point in the watershed where debris flows occur. We present an inventory technique that limits a land classification algorithm to areas that are upstream from this scaling break determined from DS plots of five streams in the Great Smoky Mountains National Park (GSMNP) region of the southern Appalachians. Topographic data for the DS plots and the

  20. Autonomic information flow improves prognostic impact of task force HRV monitoring.

    PubMed

    Hoyer, Dirk; Friedrich, Holger; Frank, Birgit; Pompe, Bernd; Baranowski, Rafal; Zebrowski, Jan J; Schmidt, Hendrik

    2006-03-01

    Heart rate variability (HRV) represents the cardiovascular control mediated by the autonomic nervous system and other mechanisms. In the established task force HRV monitoring different cardiovascular control mechanisms can approximately be identified at typical frequencies of heart rate oscillations by power spectral analysis. HRV measures assessing complex and fractal behavior partly improved clinical risk stratification. However, their relationship to (patho-)physiology is not sufficiently explored. Objective of the present work is the introduction of complexity measures of different physiologically relevant time scales. This is achieved by a new concept of the autonomic information flow (AIF) analysis which was designed according to task force HRV. First applications show that different time scales of AIF improve the risk stratification of patients with multiple organ dysfunction syndrome and cardiac arrest patients in comparison to standard HRV. Each group's significant time scales correspond to their respective pathomechanisms.

  1. Improvement of operational flood forecasting through the assimilation of satellite observations and multiple river flow data

    NASA Astrophysics Data System (ADS)

    Castelli, Fabio; Ercolani, Giulia

    2016-05-01

    Data assimilation has the potential to improve flood forecasting. However, it is rarely employed in distributed hydrologic models for operational predictions. In this study, we present variational assimilation of river flow data at multiple locations and of land surface temperature (LST) from satellite in a distributed hydrologic model that is part of the operational forecasting chain for the Arno river, in central Italy. LST is used to estimate initial condition of soil moisture through a coupled surface energy/water balance scheme. We present here several hindcast experiments to assess the performances of the assimilation system. The results show that assimilation can significantly improve flood forecasting, although in the limit of data error and model structure.

  2. A novel class of laboratory middleware. Promoting information flow and improving computerized provider order entry.

    PubMed

    Grisson, Ricky; Kim, Ji Yeon; Brodsky, Victor; Kamis, Irina K; Singh, Balaji; Belkziz, Sidi M; Batra, Shalini; Myers, Harold J; Demyanov, Alexander; Dighe, Anand S

    2010-06-01

    A central duty of the laboratory is to inform clinicians about the availability and usefulness of laboratory testing. In this report, we describe a new class of laboratory middleware that connects the traditional clinical laboratory information system with the rest of the enterprise, facilitating information flow about testing services. We demonstrate the value of this approach in efficiently supporting an inpatient order entry application. We also show that order entry monitoring and iterative middleware updates can enhance ordering efficiency and promote improved ordering practices. Furthermore, we demonstrate the value of algorithmic approaches to improve the accuracy and completeness of laboratory test searches. We conclude with a discussion of design recommendations for middleware applications and discuss the potential role of middleware as a sharable, centralized repository of laboratory test information.

  3. Improving post-wildfire hydrologic simulations with ParFlow in southern California

    NASA Astrophysics Data System (ADS)

    Lopez, Sonya; Kinoshita, Alicia; Atchley, Adam

    2016-04-01

    Wildfires alter the natural hydrologic processes within a watershed and may impact hydrologic characteristics including surface runoff and subsurface water storage. Generally, post-fire hydrologic models are either one-dimensional, empirically-based models, or two-dimensional, conceptually-based models with lumped parameter distributions. These models are useful in providing runoff measurements at the watershed outlet; however, do not provide distributed hydrologic simulation at each point within the watershed. This work uses ParFlow, a three-dimensional, distributed hydrologic model to represent soil burn severity and evaluate vegetation recovery rate impacts on water components. This model is developed for Devil Canyon, a watershed burned in 2003 by the Old Fire in southern California. The domain uses a 30m-cell size resolution over a 6.7 km by 6.4 km lateral extent. The subsurface reaches 30 m and is assigned a variable cell thickness, allowing an explicit consideration of the soil burn severity throughout the stages of recovery and vegetation regrowth. Vegetation regrowth is monitored using satellite-based Enhanced Vegetation Index (EVI) products. Pre- and post-fire hydrologic responses are evaluated using runoff measurements at the watershed outlet, and using water component (overland flow, lateral flow, baseflow) measurements. The long-term continuous simulations will improve our understanding of post-fire hydrological partitioning between water balance components and the spatial variability of watershed processes.

  4. Recalibration of the Shear Stress Transport Model to Improve Calculation of Shock Separated Flows

    NASA Technical Reports Server (NTRS)

    Georgiadis, Nicholas J.; Yoder, Dennis A.

    2013-01-01

    The Menter Shear Stress Transport (SST) k . turbulence model is one of the most widely used two-equation Reynolds-averaged Navier-Stokes turbulence models for aerodynamic analyses. The model extends Menter s baseline (BSL) model to include a limiter that prevents the calculated turbulent shear stress from exceeding a prescribed fraction of the turbulent kinetic energy via a proportionality constant, a1, set to 0.31. Compared to other turbulence models, the SST model yields superior predictions of mild adverse pressure gradient flows including those with small separations. In shock - boundary layer interaction regions, the SST model produces separations that are too large while the BSL model is on the other extreme, predicting separations that are too small. In this paper, changing a1 to a value near 0.355 is shown to significantly improve predictions of shock separated flows. Several cases are examined computationally and experimental data is also considered to justify raising the value of a1 used for shock separated flows.

  5. Reducing metal alloy powder costs for use in powder bed fusion additive manufacturing: Improving the economics for production

    NASA Astrophysics Data System (ADS)

    Medina, Fransisco

    Titanium and its associated alloys have been used in industry for over 50 years and have become more popular in the recent decades. Titanium has been most successful in areas where the high strength to weight ratio provides an advantage over aluminum and steels. Other advantages of titanium include biocompatibility and corrosion resistance. Electron Beam Melting (EBM) is an additive manufacturing (AM) technology that has been successfully applied in the manufacturing of titanium components for the aerospace and medical industry with equivalent or better mechanical properties as parts fabricated via more traditional casting and machining methods. As the demand for titanium powder continues to increase, the price also increases. Titanium spheroidized powder from different vendors has a price range from 260/kg-450/kg, other spheroidized alloys such as Niobium can cost as high as $1,200/kg. Alternative titanium powders produced from methods such as the Titanium Hydride-Dehydride (HDH) process and the Armstrong Commercially Pure Titanium (CPTi) process can be fabricated at a fraction of the cost of powders fabricated via gas atomization. The alternative powders can be spheroidized and blended. Current sectors in additive manufacturing such as the medical industry are concerned that there will not be enough spherical powder for production and are seeking other powder options. It is believed the EBM technology can use a blend of spherical and angular powder to build fully dense parts with equal mechanical properties to those produced using traditional powders. Some of the challenges with angular and irregular powders are overcoming the poor flow characteristics and the attainment of the same or better packing densities as spherical powders. The goal of this research is to demonstrate the feasibility of utilizing alternative and lower cost powders in the EBM process. As a result, reducing the cost of the raw material to reduce the overall cost of the product produced with

  6. Additives in plastics.

    PubMed Central

    Deanin, R D

    1975-01-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products. PMID:1175566

  7. Additives in plastics.

    PubMed

    Deanin, R D

    1975-06-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products.

  8. An improved immersed boundary-lattice Boltzmann method for simulating three-dimensional incompressible flows

    NASA Astrophysics Data System (ADS)

    Wu, J.; Shu, C.

    2010-07-01

    The recently proposed boundary condition-enforced immersed boundary-lattice Boltzmann method (IB-LBM) [14] is improved in this work to simulate three-dimensional incompressible viscous flows. In the conventional IB-LBM, the restoring force is pre-calculated, and the non-slip boundary condition is not enforced as compared to body-fitted solvers. As a result, there is a flow penetration to the solid boundary. This drawback was removed by the new version of IB-LBM [14], in which the restoring force is considered as unknown and is determined in such a way that the non-slip boundary condition is enforced. Since Eulerian points are also defined inside the solid boundary, the computational domain is usually regular and the Cartesian mesh is used. On the other hand, to well capture the boundary layer and in the meantime, to save the computational effort, we often use non-uniform mesh in IB-LBM applications. In our previous two-dimensional simulations [14], the Taylor series expansion and least squares-based lattice Boltzmann method (TLLBM) was used on the non-uniform Cartesian mesh to get the flow field. The final expression of TLLBM is an algebraic formulation with some weighting coefficients. These coefficients could be computed in advance and stored for the following computations. However, this way may become impractical for 3D cases as the memory requirement often exceeds the machine capacity. The other way is to calculate the coefficients at every time step. As a result, extra time is consumed significantly. To overcome this drawback, in this study, we propose a more efficient approach to solve lattice Boltzmann equation on the non-uniform Cartesian mesh. As compared to TLLBM, the proposed approach needs much less computational time and virtual storage. Its good accuracy and efficiency are well demonstrated by its application to simulate the 3D lid-driven cubic cavity flow. To valid the combination of proposed approach with the new version of IBM [14] for 3D flows

  9. Extracting kinetic freeze-out temperature and radial flow velocity from an improved Tsallis distribution

    NASA Astrophysics Data System (ADS)

    Lao, Hai-Ling; Liu, Fu-Hu; Lacey, Roy A.

    2017-03-01

    We analyze the transverse-momentum (pT) spectra of identified particles (π^{±}, K^{±}, p, and \\bar{p}) produced in gold-gold (Au-Au) and lead-lead (Pb-Pb) collisions over a √{s_{NN}} (center-of-mass energy per nucleon pair) range from 14.5 GeV (one of the Relativistic Heavy Ion Collider (RHIC) energies) to 2.76 TeV (one of the Large Hadron Collider (LHC) energies). For the spectra with a narrow pT range, an improved Tsallis distribution which is in fact the Tsallis distribution with radial flow is used. For the spectra with a wide pT range, a superposition of the improved Tsallis distribution and an inverse power law is used. Both the extracted kinetic freeze-out temperature (T0) and radial flow velocity (βT) increase with the increase of √{s_{NN}}, which indicates a higher excitation and larger expansion of the interesting system at the LHC. Both the values of T0 and βT in central collisions are slightly larger than those in peripheral collisions, and they are independent of isospin and slightly dependent on mass.

  10. Exploring a Method for Improving Turbulent Separated-Flow Predictions with kappa-omega Models

    NASA Technical Reports Server (NTRS)

    Rumsey, Christopher L.

    2009-01-01

    A particular failing of Reynolds-averaged Navier-Stokes separated turbulent flow computations is addressed within the context of a kappa-omega two-equation turbulence model. The failing is the tendency for turbulence models to under-predict turbulent shear stress in the shear layers of some separation bubbles, yielding late boundary layer reattachment and recovery. Inspired by unpublished work of Volker, Langtry, and Menter, the author undertook an independent investigation in an attempt to improve the ability of the Menter shear stress transport (SST) model to predict flowfield characteristics in and downstream of separation bubbles. The fix is an ad hoc term that is a function of the local ratio of turbulent production to dissipation; it is used to multiply the omega-destruction term, increasing eddy viscosity in separated regions. With this fix, several flowfields are investigated. Results show that, although the "separation fix" can provide dramatic improvement in some cases, it is not consistently good for all flows. Thus, although it may prove helpful in many situations in its current form, this model may benefit from further refinements, including better sensitization to the energetics of turbulence in the separated region.

  11. [Improvement in the efficiency of an ambulatory service case load by applying a computerized method (patient flow analysis)].

    PubMed

    Benussi, G; Canciani, G P; de Luyk, S; Parco, S; Visconti, P; Grandolfo, M; Mangiarotti, M A

    1984-03-01

    The authors describe the application of a technique called Patient Flow Analysis aimed at the improvement of Clinic Personnel efficiency and reduction of patient waiting time. Results were satisfactory and encourage further experiences.

  12. Environmental flow assessment for improvement of ecological integrity in the Haihe River Basin, China.

    PubMed

    Yang, Tao; Liu, Jingling; Chen, Qiuying; Zhang, Jing; Yang, Yi

    2014-05-01

    The Haihe River Basin is a semiarid water resources area of China. River ecosystem was degraded for high population density and intensive water resources development activities. To assist in the improvement of the ecological integrity of this river ecosystem, an environmental flow assessment model was developed that consider both spatial structure and dominant eco-function parameters. River ecosystem was divided into three sub-ecosystems which including river reach, wetland and estuary based on the spatial structure of river ecosystem. River reach was divided into three types which including habitat restoration type (HR), water quality restoration type (WQR) and vegetation restoration substitute water quantity restoration type (VRSWQR) according to their dominant eco-function. The spatio-temporal distribution of environmental flow (EF) for the river ecosystem in the Haihe River Basin was assessed based on the model. The results indicate that the EF for the river reach, wetland, and estuary are 2.267, 1.532, and 0.972 billion m(3), respectively. The EF for HR type of river reach, the WQR type of river reach and VRSWQR type of river reach are 1.140, 1.138, and 0.154 billion m(3), which are equal to 4.320, 4.312, and 0.584 % of the average annual flow of 26.39 billion m(3), respectively. EF for river ecosystem in wet period (June-September), normal period (October-January) and dry period (February-May) are 2.999, 0.951, and 0.821 billion m(3), respectively. Annual EF for river ecosystem of the Basin are 4.771 billion m(3), which accounts for 18 % of the average annual flows of 26.39 billion m(3).

  13. Improving Long-term Post-wildfire hydrologic simulations using ParFlow

    NASA Astrophysics Data System (ADS)

    Lopez, S. R.; Kinoshita, A. M.

    2015-12-01

    Wildfires alter the natural hydrologic processes within a watershed. After vegetation is burned, the combustion of organic material and debris settles into the soil creating a hydrophobic layer beneath the soil surface with varying degree of thickness and depth. Vegetation regrowth rates vary as a function of radiative exposure, burn severity, and precipitation patterns. Hydrologic models used by the Burned Area Emergency Response (BAER) teams use input data and model calibration constraints that are generally either one-dimensional, empirically-based models, or two-dimensional, conceptually-based models with lumped parameter distributions. These models estimate runoff measurements at the watershed outlet; however, do not provide a distributed hydrologic simulation at each point within the watershed. This work uses ParFlow, a three-dimensional, distributed hydrologic model to (1) correlate burn severity with hydrophobicity, (2) evaluate vegetation recovery rate on water components, and (3) improve flood prediction for managers to help with resource allocation and management operations in burned watersheds. ParFlow is applied to Devil Canyon (43 km2) in San Bernardino, California, which was 97% burned in the 2003 Old Fire. The model set-up uses a 30m-cell size resolution over a 6.7 km by 6.4 km lateral extent. The subsurface reaches 30 m and is assigned a variable cell thickness. Variable subsurface thickness allows users to explicitly consider the degree of recovery throughout the stages of regrowth. Burn severity maps from remotely sensed imagery are used to assign initial hydrophobic layer parameters and thickness. Vegetation regrowth is represented with satellite an Enhanced Vegetation Index. Pre and post-fire hydrologic response is evaluated using runoff measurements at the watershed outlet, and using water component (overland flow, lateral flow, baseflow) measurements.

  14. Does Coronary Stenting Following Balloon Angioplasty Improve Myocardial Fractional Flow Reserve?

    SciTech Connect

    Takeuchi, Masaaki; Himeno, Etsuro

    1998-11-15

    Purpose: Suboptimal distal coronary flow reserve after successful balloon angioplasty has been attributed to angiographically unrecognized inadequate lumen expansion, and adjunct coronary stenting has been shown to improve coronary flow reserve. The aim of this study was to investigate whether myocardial fractional flow reserve (FFRmyo) would increase further after coronary stenting compared with balloon angioplasty alone in the same patient group. Methods: FFRmyo and quantitative coronary angiography were obtained before and after pre-stent balloon dilation, and again after stent placement in 11 patients (7 left anterior descending artery, 3 right coronary artery and 1 left circumflex artery). FFRmyo was calculated as the ratio of Pd/Pa during intracoronary adenosine 5'-triphosphate (50 {mu}g and 20 {mu}g in the left and right coronary arteries, respectively)-induced maximum hyperemia, where Pd represents mean distal coronary pressure measured by a 2.1 Fr infusion catheter and Pa represents mean aortic pressure measured by the guiding catheter. Results: Percent diameter stenosis significantly decreased after balloon angioplasty (74% {+-} 15% vs 37% {+-} 17%, p < 0.001), and decreased further after stent placement (18% {+-} 10%, p < 0.001 vs baseline and balloon angioplasty). FFRmyo after coronary stenting (0.85 {+-} 0.09) was significantly higher than that at baseline (0.51 {+-} 0.16, p < 0.001) and after balloon angioplasty (0.77 {+-} 0.11, p < 0.05). There was a significant correlation between angiographic variables and FFRmyo. The increase in lumen dimensions after coronary stenting was followed by a further significant improvement of FFRmyo. Conclusion: These results suggest that coronary stenting may provide a more favorable functional status and lumen geometry of residual coronary stenosis compared with balloon angioplasty alone.

  15. Improved Flow Cytometric Assessment Reveals Distinct Microvesicle (Cell-Derived Microparticle) Signatures in Joint Diseases

    PubMed Central

    György, Bence; Szabó, Tamás G.; Turiák, Lilla; Wright, Matthew; Herczeg, Petra; Lédeczi, Zsigmond; Kittel, Ágnes; Polgár, Anna; Tóth, Kálmán; Dérfalvi, Beáta; Zelenák, Gergő; Böröcz, István; Carr, Bob; Nagy, György; Vékey, Károly; Gay, Steffen; Falus, András; Buzás, Edit I.

    2012-01-01

    Introduction Microvesicles (MVs), earlier referred to as microparticles, represent a major type of extracellular vesicles currently considered as novel biomarkers in various clinical settings such as autoimmune disorders. However, the analysis of MVs in body fluids has not been fully standardized yet, and there are numerous pitfalls that hinder the correct assessment of these structures. Methods In this study, we analyzed synovial fluid (SF) samples of patients with osteoarthritis (OA), rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA). To assess factors that may confound MV detection in joint diseases, we used electron microscopy (EM), Nanoparticle Tracking Analysis (NTA) and mass spectrometry (MS). For flow cytometry, a method commonly used for phenotyping and enumeration of MVs, we combined recent advances in the field, and used a novel approach of differential detergent lysis for the exclusion of MV-mimicking non-vesicular signals. Results EM and NTA showed that substantial amounts of particles other than MVs were present in SF samples. Beyond known MV-associated proteins, MS analysis also revealed abundant plasma- and immune complex-related proteins in MV preparations. Applying improved flow cytometric analysis, we demonstrate for the first time that CD3+ and CD8+ T-cell derived SF MVs are highly elevated in patients with RA compared to OA patients (p = 0.027 and p = 0.009, respectively, after Bonferroni corrections). In JIA, we identified reduced numbers of B cell-derived MVs (p = 0.009, after Bonferroni correction). Conclusions Our results suggest that improved flow cytometric assessment of MVs facilitates the detection of previously unrecognized disease-associated vesicular signatures. PMID:23185418

  16. Improved instrumentation for blood flow velocity measurements in the microcirculation of small animals

    SciTech Connect

    Mesquita, Jayme Alves Jr. de; Bouskela, Eliete; Wajnberg, Eliane; Lopes de Melo, Pedro

    2007-02-15

    Microcirculation is the generic name of vessels with internal diameter less than 100 {mu}m of the circulatory system, whose main functions are tissue nutrition and oxygen supply. In microcirculatory studies, it is important to know the amount of oxyhemoglobin present in the blood and how fast it is moving. The present work describes improvements introduced in a classical hardware-based instrument that has usually been used to monitor blood flow velocity in the microcirculation of small animals. It consists of a virtual instrument that can be easily incorporated into existing hardware-based systems, contributing to reduce operator related biases and allowing digital processing and storage. The design and calibration of the modified instrument are described as well as in vitro and in vivo results obtained with electrical models and small animals, respectively. Results obtained in in vivo studies showed that this new system is able to detect a small reduction in blood flow velocity comparing arteries and arterioles (p<0.002) and a further reduction in capillaries (p<0.0001). A significant increase in velocity comparing capillaries and venules (p<0.001) and venules and veins (p<0.001) was also observed. These results are in close agreement with biophysical principles. Moreover, the improvements introduced in the device allowed us to clearly observe changes in blood flow introduced by a pharmacological intervention, suggesting that the system has enough temporal resolution to track these microcirculatory events. These results were also in close conformity to physiology, confirming the high scientific potential of the modified system and indicating that this instrument can also be useful for pharmacological evaluations.

  17. Composition and Flow Behavior of F-Canyon Tank 804 Sludge following Manganese Addition and pH Adjustment

    SciTech Connect

    Poirier, M. R.; Stallings, M. E.; Burket, P.R.; Fink, S. D.

    2005-11-30

    The Site Deactivation and Decommissioning (SDD) Organization is evaluating options to disposition the 800 underground tanks (including removal of the sludge heels from these tanks). To support this effort, SDD requested assistance from Savannah River National Laboratory (SRNL) personnel to examine the composition and flow characteristics of the Tank 804 sludge slurry after diluting it 10:1 with water, adding manganese nitrate to produce a slurry containing 5.5 wt % manganese (40:1 ratio of Mn:Pu), and adding sufficient 8 M caustic to raise the pH to 7, 10, and 14. Researchers prepared slurries containing one part Tank 804 sludge and 10 parts water. The water contained 5.5 wt % manganese (which SDD will add to poison the plutonium in Tank 804) and was pH adjusted to 3, 7, 10, or 14. They hand mixed (i.e., shook) these slurries and allowed them to sit overnight. With the pH 3, 7, and 10 slurries, much of the sludge remained stuck to the container wall. With the pH 14 slurry, most of the sludge appeared to be suspended in the slurry. They collected samples from the top and bottom of each container, which were analyzed for plutonium, manganese, and organic constituents. Following sampling, they placed the remaining material into a viscometer and measured the relationship between applied shear stress and shear rate. The pH 14 slurry was placed in a spiral ''race track'' apparatus and allowed to gravity drain.

  18. Improvement of methyl orange dye biotreatment by a novel isolated strain, Aeromonas veronii GRI, by SPB1 biosurfactant addition.

    PubMed

    Mnif, Inès; Maktouf, Sameh; Fendri, Raouia; Kriaa, Mouna; Ellouze, Semia; Ghribi, Dhouha

    2016-01-01

    Aeromonas veronii GRI (KF964486), isolated from acclimated textile effluent after selective enrichment on azo dye, was assessed for methyl orange biodegradation potency. Results suggested the potential of this bacterium for use in effective treatment of azo-dye-contaminated wastewaters under static conditions at neutral and alkaline pH value, characteristic of typical textile effluents. The strain could tolerate higher doses of dyes as it was able to decolorize up to 1000 mg/l. When used as microbial surfactant to enhance methyl orange biodecolorization, Bacillus subtilis SPB1-derived lipopeptide accelerated the decolorization rate and maximized slightly the decolorization efficiency at an optimal concentration of about 0.025%. In order to enhance the process efficiency, a Taguchi design was conducted. Phytotoxicity bioassay using sesame and radish seeds were carried out to assess the biotreatment effectiveness. The bacterium was able to effectively decolorize the azo dye when inoculated with an initial optical density of about 0.5 with 0.25% sucrose, 0.125% yeast extract, 0.01% SPB1 biosurfactant, and when conducting an agitation phase of about 24 h after static incubation. Germination potency showed an increase toward the nonoptimized conditions indicating an improvement of the biotreatment. When comparing with synthetic surfactants, a drastic decrease and an inhibition of orange methyl decolorization were observed in the presence of CTAB and SDS. The nonionic surfactant Tween 80 had a positive effect on methyl orange biodecolorization. Also, studies ensured that methyl orange removal by this strain could be due to endocellular enzymatic activities. To conclude, the addition of SPB1 bioemulsifier reduced energy costs by reducing effective decolorization period, biosurfactant stimulated bacterial decolorization method may provide highly efficient, inexpensive, and time-saving procedure in treatment of textile effluents.

  19. Ducted fan inlet/exit and rotor tip flow improvements for vertical lift systems

    NASA Astrophysics Data System (ADS)

    Akturk, Ali

    The current research utilized experimental and computational techniques in 5" and 22" diameter ducted fan test systems that have been custom designed and manufactured. Qualitative investigation of flow around the ducted fan was also performed using smoke flow visualizations. Quantitative measurements consisted of 2D and 3D velocity measurements using planar and Stereoscopic Particle Image Velocimetry (PIV and SPIV), high resolution total pressure measurements using Kiel total pressure probes and real time six-component force and torque measurements. The computational techniques used in this thesis included a recently developed radial equilibrium based rotor model(REBRM) and a three dimensional Reynolds-Averaged Navier Stokes (RANS) based CFD model. A radial equilibrium based rotor model (REBRM) developed by the author was effectively integrated into a three-dimensional RANS based computational system. The PIV measurements and computational flow predictions using (REBRM) near the fan inlet plane were in a good agreement at hover and forward flight conditions. The aerodynamic modifications resulting from the fan inlet flow distortions in forward flight regime were clearly captured in 2D PIV results. High resolution total pressure measurements at the downstream of the fan rotor showed that tip leakage, rotor hub separation, and passage flow related total pressure losses were dominant in hover condition. However, the losses were dramatically increased in forward flight because of inlet lip separation and distortion. A novel ducted fan inlet flow conditioning concept named "Double Ducted Fan" (DDF) was developed. The (DDF) concept has a potential to significantly improve the performance and controllability of VTOL UAVs and many other ducted fan based vertical lift systems. The new concept that will significantly reduce the inlet lip separation related performance penalties used a secondary stationary duct system to control "inlet lip separation" occurring especially at

  20. Physiologically-relevant measurements of flow through coils and stents: towards improved modeling of endovascular treatment of intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Barbour, Michael; Levitt, Michael; Geindreau, Christian; Rolland Du Roscoat, Sabine; Johnson, Luke; Chivukula, Keshav; Aliseda, Alberto

    2016-11-01

    The hemodynamic environment in cerebral aneurysms undergoing flow-diverting stent (FDS) or coil embolization treatment plays a critical role in long-term outcomes. Standard modeling approaches to endovascular coils and FDS simplify the complex geometry into a homogenous porous volume or surface through the addition of a Darcy-Brinkman pressure loss term in the momentum equation. The inertial and viscous loss coefficients are typically derived from published in vitro studies of pressure loss across FDS and coils placed in a straight tube, where the only fluid path is across the treatment - an unrealistic representation of treatment apposition in vivo. The pressure drop across FDS and coils in side branch aneurysms located on curved parent vessels is measured. Using PIV, the velocity at the aneurysm neck plane is reconstructed and used to determine loss coefficients for better models of endovascular coils or FDS that account for physiological placement and vessel curvature. These improved models are incorporated into CFD simulations and validated against in vitro model PIV velocity, as well as compared to microCT-based coil/stent-resolving CFD simulations of patient-specific treated aneurysm flow.

  1. Improving the bond strength between steel rebar and concrete by ozone treatment of rebar and polymer addition to concrete

    SciTech Connect

    Fu, X.; Chung, D.D.L.

    1997-05-01

    Ozone treatment of steel rebar, together with latex addition (20% by weight of cement) to concrete, resulted in a 39% increase in the shear bond strength between rebar and concrete, compared to a 25% increase resulted from either ozone treatment alone or latex addition alone. Ozone treatment and latex addition resulted in similarly small increases in the contact electrical resistivity between rebar and concrete. Methylcellulose addition (0.4% by weight of cement) to concrete gave slightly less bond strength increase than the latex addition, but did not affect the contact resistivity.

  2. Optimal Control of Shock Tube Flow via Water Addition with Application to Ignition Overpressure Mitigation in Launch Vehicles

    NASA Astrophysics Data System (ADS)

    Moshman, Nathan

    2009-11-01

    Ignition Overpressure (IOP) in launch vehicles occurs at the start of ignition when a steep rise in pressure propagates outward from the rocket nozzle. It is crucial to minimize the overpressure so as to decrease risk of damage to the rocket body. Currently, CFD studies exist on this situation but there are no optimization studies of the water addition as a means to suppress the IOP. The proposed dissertation will use a numerical method to compute an approximate solution for an optimal control problem constrained by the one-dimensional Euler PDEs of fluid dynamics as well as volume fraction conservation. A model for inter-phase transport of mass momentum and energy and fluid interface quantities will be given. The control will be water addition from external nozzles. The adjoint system of equations will be derived and discretized. Necessary optimal conditions will be derived. An SQP method will solve an optimal situation. Predictions will be validated against shock tube experiments at the NPS rocket lab.

  3. Treatment of denture-related stomatitis improves endothelial function assessed by flow-mediated vascular dilation

    PubMed Central

    Osmenda, Grzegorz; Maciąg, Joanna; Wilk, Grzegorz; Maciąg, Anna; Nowakowski, Daniel; Loster, Jolanta; Dembowska, Elżbieta; Robertson, Douglas; Guzik, Tomasz

    2016-01-01

    Introduction The presence of oral inflammation has recently been linked with the pathogenesis of cardiovascular diseases. While numerous studies have described links between periodontitis and endothelial dysfunction, little is known about the influence of denture-related stomatitis (DRS) on cardiovascular risk. Therefore, the aim of this study was to determine whether the treatment of DRS can lead to improvement of the clinical measures of vascular dysfunction. Material and methods The DRS patients were treated with a local oral antifungal agent for 3 weeks. Blood pressure, flow-mediated dilatation (FMD) and nitroglycerine-mediated vascular dilatation (NMD) were measured during three study visits: before treatment, one day and two months after conclusion of antifungal therapy. Results Flow-mediated dilatation measurements showed significant improvement of endothelial function 2 months after treatment (FMD median 5%, 95 CI: 3–8.3 vs. 11%, 95% CI: 8.8–14.4; p < 0.01), while there was no difference in control, endothelium-independent vasorelaxations (NMD; median = 15.3%, 95% CI: 10.8–19.3 vs. 12.7%, 95% CI: 10.6–15; p = 0.3). Other cardiovascular parameters such as systolic (median = 125 mm Hg; 95% CI: 116–129 vs. 120 mm Hg, 95% CI: 116–126; p = 0.1) as well as diastolic blood pressure and heart rate (median = 65.5 bpm, 95% CI: 56.7–77.7 vs. 71 bpm, 95% CI: 66.7–75; p = 0.5) did not change during or after the treatment. Conclusions Treatment of DRS is associated with improvement of endothelial function. Since endothelial dysfunction is known to precede the development of severe cardiovascular disorders such as atherosclerosis and hypertension, patients should be more carefully screened for DRS in general dental practice, and immediate DRS treatment should be advised. PMID:28144257

  4. Enhancement of the anaerobic hydrolysis and fermentation of municipal solid waste in leachbed reactors by varying flow direction during water addition and leachate recycle.

    PubMed

    Uke, Matthew N; Stentiford, Edward

    2013-06-01

    Poor performance of leachbed reactors (LBRs) is attributed to channelling, compaction from waste loading, unidirectional water addition and leachate flow causing reduced hydraulic conductivity and leachate flow blockage. Performance enhancement was evaluated in three LBRs M, D and U at 22 ± 3°C using three water addition and leachate recycle strategies; water addition was downflow in D throughout, intermittently upflow and downflow in M and U with 77% volume downflow in M, 54% volume downflow in U while the rest were upflow. Leachate recycle was downflow in D, alternately downflow and upflow in M and upflow in U. The strategy adopted in U led to more water addition (30.3%), leachate production (33%) and chemical oxygen demand (COD) solubilisation (33%; 1609 g against 1210 g) compared to D (control). The total and volatile solids (TS and VS) reductions were similar but the highest COD yield (g-COD/g-TS and g-COD/g-VS removed) was in U (1.6 and 1.9); the values were 1.33 and 1.57 for M, and 1.18 and 1.41 for D respectively. The strategy adopted in U showed superior performance with more COD and leachate production compared to reactors M and D.

  5. Continuous-Flow Left Ventricular Assist Device Support Improves Myocardial Supply:Demand in Chronic Heart Failure.

    PubMed

    Soucy, Kevin G; Bartoli, Carlo R; Phillips, Dustin; Giridharan, Guruprasad A; Sobieski, Michael A; Wead, William B; Dowling, Robert D; Wu, Zhongjun J; Prabhu, Sumanth D; Slaughter, Mark S; Koenig, Steven C

    2017-02-06

    Continuous-flow left ventricular assist devices (CF LVADs) are rotary blood pumps that improve mean blood flow, but with potential limitations of non-physiological ventricular volume unloading and diminished vascular pulsatility. In this study, we tested the hypothesis that left ventricular unloading with increasing CF LVAD flow increases myocardial flow normalized to left ventricular work. Healthy (n = 8) and chronic ischemic heart failure (IHF, n = 7) calves were implanted with CF LVADs. Acute hemodynamics and regional myocardial blood flow were measured during baseline (LVAD off, clamped), partial (2-4 L/min) and full (>4 L/min) LVAD support. IHF calves demonstrated greater reduction of cardiac energy demand with increasing LVAD support compared to healthy calves, as calculated by rate-pressure product. Coronary artery flows (p < 0.05) and myocardial blood flow (left ventricle (LV) epicardium and myocardium, p < 0.05) decreased with increasing LVAD support in normal calves. In the IHF model, blood flow to the septum, LV, LV epicardium, and LV myocardium increased significantly with increasing LVAD support when normalized to cardiac energy demand (p < 0.05). In conclusion, myocardial blood flow relative to cardiac demand significantly increased in IHF calves, thereby demonstrating that CF LVAD unloading effectively improves cardiac supply and demand ratio in the setting of ischemic heart failure.

  6. An improved multiphase lattice Boltzmann flux solver for three-dimensional flows with large density ratio and high Reynolds number

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Shu, C.; Yang, L. M.

    2015-12-01

    An improved multiphase lattice Boltzmann flux solver (MLBFS) is proposed in this work for effective simulation of three-dimensional (3D) multiphase flows with large density ratio and high Reynolds number. As a finite volume scheme, the MLBFS originally proposed in [27] applies the finite volume method to solve for macroscopic flow variables directly. The fluxes are reconstructed locally at each cell interface by using the standard LBM solutions. Due to the modeling error of the standard LBM, the reconstructed fluxes deviate from those in the Navier-Stokes equations; and to compensate this error, a complex tensor is introduced in the original MLBFS. However, the computation of the tensor introduces additional complexity and usually needs a relatively thicker interface thickness to maintain numerical stability, which makes the solver be complex and inefficient in the 3D case. To remove this drawback, in this work, a theoretical analysis to the formulations obtained from the Chapman-Enskog expansion is conducted. It is shown that the modeling error can be effectively removed by modifying the computation of the equilibrium density distribution function. With this improvement, the proposed 3D MLBFS not only avoids the calculation of the compensation tensor but also is able to maintain numerical stability with very thin interface thickness. Several benchmark cases, including the challenging droplet impacting on a dry surface, head-on collisions of binary droplets and droplet splashing on a thin film with density ratio 1000 and Reynolds number up to 3000, are studied to validate the proposed solver. The obtained results agree well with the published data.

  7. Fast Gas Replacement in Plasma Process Chamber by Improving Gas Flow Pattern

    NASA Astrophysics Data System (ADS)

    Morishita, Sadaharu; Goto, Tetsuya; Akutsu, Isao; Ohyama, Kenji; Ito, Takashi; Ohmi, Tadahiro

    2009-01-01

    The precise and high-speed alteration of various gas species is important for realizing precise and well-controlled multiprocesses in a single plasma process chamber with high throughput. The gas replacement times in the replacement of N2 by Ar and that of H2 by Ar are measured in a microwave excited high-density and low electron-temperature plasma process chamber at various working pressures and gas flow rates, incorporating a new gas flow control system, which can avoid overshoot of the gas pressure in the chamber immediately after the valve operation, and a gradational lead screw booster pump, which can maintain excellent pumping capability for various gas species including lightweight gases such as H2 in a wide pressure region from 10-1 to 104 Pa. Furthermore, to control the gas flow pattern in the chamber, upper ceramic shower plates, which have thousands of very fine gas injection holes (numbers of 1200 and 2400) formed with optimized allocation on the plates, are adopted, while the conventional gas supply method in the microwave-excited plasma chamber uses many holes only opened at the sidewall of the chamber (gas ring). It has been confirmed that, in the replacement of N2 by Ar, a short replacement time of approximately 1 s in the cases of 133 and 13.3 Pa and approximately 3 s in the case of 4 Pa can be achieved when the upper shower plate has 2400 holes, while a replacement time longer than approximately 10 s is required for all pressure cases where the gas ring is used. In addition, thanks to the excellent pumping capability of the gradational lead screw booster pump for lightweight gases, it has also been confirmed that the replacement time of H2 by Ar is almost the same as that of N2 by Ar.

  8. Subthalamic nucleus stimulation-induced regional blood flow responses correlate with improvement of motor signs in Parkinson disease.

    PubMed

    Karimi, M; Golchin, N; Tabbal, S D; Hershey, T; Videen, T O; Wu, J; Usche, J W M; Revilla, F J; Hartlein, J M; Wernle, A R; Mink, J W; Perlmutter, J S

    2008-10-01

    Deep brain stimulation of the subthalamic nucleus (STN DBS) improves motor symptoms in idiopathic Parkinson's disease, yet the mechanism of action remains unclear. Previous studies indicate that STN DBS increases regional cerebral blood flow (rCBF) in immediate downstream targets but does not reveal which brain regions may have functional changes associated with improved motor manifestations. We studied 48 patients with STN DBS who withheld medication overnight and underwent PET scans to measure rCBF responses to bilateral STN DBS. PET scans were performed with bilateral DBS OFF and ON in a counterbalanced order followed by clinical ratings of motor manifestations using Unified Parkinson Disease Rating Scale 3 (UPDRS 3). We investigated whether improvement in UPDRS 3 scores in rigidity, bradykinesia, postural stability and gait correlate with rCBF responses in a priori determined regions. These regions were selected based on a previous study showing significant STN DBS-induced rCBF change in the thalamus, midbrain and supplementary motor area (SMA). We also chose the pedunculopontine nucleus region (PPN) due to mounting evidence of its involvement in locomotion. In the current study, bilateral STN DBS improved rigidity (62%), bradykinesia (44%), gait (49%) and postural stability (56%) (paired t-tests: P < 0.001). As expected, bilateral STN DBS also increased rCBF in the bilateral thalami, right midbrain, and decreased rCBF in the right premotor cortex (P < 0.05, corrected). There were significant correlations between improvement of rigidity and decreased rCBF in the SMA (r(s) = -0.4, P < 0.02) and between improvement in bradykinesia and increased rCBF in the thalamus (r(s) = 0.31, P < 0.05). In addition, improved postural reflexes correlated with decreased rCBF in the PPN (r(s) = -0.38, P < 0.03). These modest correlations between selective motor manifestations and rCBF in specific regions suggest possible regional selectivity for improvement of different motor

  9. A systematic review of triage-related interventions to improve patient flow in emergency departments

    PubMed Central

    2011-01-01

    Background Overcrowding in emergency departments is a worldwide problem. A systematic literature review was undertaken to scientifically explore which interventions improve patient flow in emergency departments. Methods A systematic literature search for flow processes in emergency departments was followed by assessment of relevance and methodological quality of each individual study fulfilling the inclusion criteria. Studies were excluded if they did not present data on waiting time, length of stay, patients leaving the emergency department without being seen or other flow parameters based on a nonselected material of patients. Only studies with a control group, either in a randomized controlled trial or in an observational study with historical controls, were included. For each intervention, the level of scientific evidence was rated according to the GRADE system, launched by a WHO-supported working group. Results The interventions were grouped into streaming, fast track, team triage, point-of-care testing (performing laboratory analysis in the emergency department), and nurse-requested x-ray. Thirty-three studies, including over 800,000 patients in total, were included. Scientific evidence on the effect of fast track on waiting time, length of stay, and left without being seen was moderately strong. The effect of team triage on left without being seen was relatively strong, but the evidence for all other interventions was limited or insufficient. Conclusions Introducing fast track for patients with less severe symptoms results in shorter waiting time, shorter length of stay, and fewer patients leaving without being seen. Team triage, with a physician in the team, will probably result in shorter waiting time and shorter length of stay and most likely in fewer patients leaving without being seen. There is only limited scientific evidence that streaming of patients into different tracks, performing laboratory analysis in the emergency department or having nurses to

  10. An improved algorithm for the modeling of vapor flow in heat pipes

    NASA Technical Reports Server (NTRS)

    Tower, Leonard K.; Hainley, Donald C.

    1989-01-01

    A heat pipe vapor flow algorithm suitable for use in codes on microcomputers is presented. The incompressible heat pipe vapor flow studies of Busse are extended to incorporate compressibility effects. The Busse velocity profile factor is treated as a function of temperature and pressure. The assumption of a uniform saturated vapor temperature determined by the local pressure at each cross section of the pipe is not made. Instead, a mean vapor temperature, defined by an energy integral, is determined in the course of the solution in addition to the pressure, saturation temperature at the wall, and the Busse velocity profile factor. For alkali metal working fluids, local species equilibrium is assumed. Temperature and pressure profiles are presented for several cases involving sodium heat pipes. An example for a heat pipe with an adiabatic section and two evaporators in sequence illustrates the ability to handle axially varying heat input. A sonic limit plot for a short evaporator falls between curves for the Busse and Levy inviscid sonic limits.

  11. An Improved Discrete-Time Model for Heterogeneous High-Speed Train Traffic Flow

    NASA Astrophysics Data System (ADS)

    Xu, Yan; Jia, Bin; Li, Ming-Hua; Li, Xin-Gang

    2016-03-01

    This paper aims to present a simulation model for heterogeneous high-speed train traffic flow based on an improved discrete-time model (IDTM). In the proposed simulation model, four train control strategies, including departing strategy, traveling strategy, braking strategy, overtaking strategy, are well defined to optimize train movements. Based on the proposed simulation model, some characteristics of train traffic flow are investigated. Numerical results indicate that the departure time intervals, the station dwell time, the section length, and the ratio of fast trains have different influence on traffic capacity and train average velocity. The results can provide some theoretical support for the strategy making of railway departments. Supported by the National Basic Research Program of China under Grant No. 2012CB725400, the National Natural Science Foundation of China under Grant No. 71222101, the Research Foundation of State Key Laboratory of Rail Traffic Control and Safety under Grant No. RCS2014ZT16, and the Fundamental Research Funds for the Central Universities No. 2015YJS088, Beijing Jiaotong University

  12. Combination of principal component analysis and optical-flow motion compensation for improved cardiac MR thermometry

    NASA Astrophysics Data System (ADS)

    Toupin, S.; de Senneville, B. Denis; Ozenne, V.; Bour, P.; Lepetit-Coiffe, M.; Boissenin, M.; Jais, P.; Quesson, B.

    2017-02-01

    The use of magnetic resonance (MR) thermometry for the monitoring of thermal ablation is rapidly expanding. However, this technique remains challenging for the monitoring of the treatment of cardiac arrhythmia by radiofrequency ablation due to the heart displacement with respiration and contraction. Recent studies have addressed this problem by compensating in-plane motion in real-time with optical-flow based tracking technique. However, these algorithms are sensitive to local variation of signal intensity on magnitude images associated with tissue heating. In this study, an optical-flow algorithm was combined with a principal component analysis method to reduce the impact of such effects. The proposed method was integrated to a fully automatic cardiac MR thermometry pipeline, compatible with a future clinical workflow. It was evaluated on nine healthy volunteers under free breathing conditions, on a phantom and in vivo on the left ventricle of a sheep. The results showed that local intensity changes in magnitude images had lower impact on motion estimation with the proposed method. Using this strategy, the temperature mapping accuracy was significantly improved.

  13. Blood flow-restricted training does not improve jump performance in untrained young men.

    PubMed

    Madarame, Haruhiko; Ochi, E; Tomioka, Y; Nakazato, K; Ishii, N

    2011-12-01

    The purpose of this study was to investigate the effect of blood flow-restricted training (BFRT) on jump performance in relation to changes in muscle strength. Seventeen untrained young men were assigned into either BFRT or normal training (NORT) groups and performed low-intensity [30-40% of one-repetition maximum (1RM)] resistance exercise (horizontal squat, 3-4 sets × 15-30 repetitions) twice a week for 10 weeks. The BFRT performed the exercise with their proximal thighs compressed by air-pressure cuffs for the purpose of blood flow restriction. Squat 1RM, muscle cross-sectional area (CSA) of quadriceps femoris, and countermovement jump (CMJ) height were measured before and after the 10-wk training period. Squat 1RM increased greater in BFRT than in NORT (19.3% vs. 9.7%, P < 0.01). Although the CSA increase was independent of groups, it tended to be larger in BFRT than in NORT (8.3% vs. 2.9%, P = 0.094). On the other hand, CMJ height did not change after the training (P = 0.51). In conclusion, the present study showed that BFRT induced muscle hypertrophy and strength increase, whereas it did not increase CMJ height in previously untrained young men. It is suggested that BFRT is ineffective in improving jump performance.

  14. Improved performance of gravitational field-flow fractionation for screening wine-making yeast varieties.

    PubMed

    Sanz, R; Torsello, B; Reschiglian, P; Puignou, L; Galceran, M T

    2002-08-09

    Performance of gravitational field-flow fractionation (GFFF) is improved here with respect to the ability to fractionate and distinguish different varieties of wine-making yeast from Saccharomyces cerevisiae. A new GFFF channel with non-polar walls has been employed to enhance fractionation selectivity and reproducibility. Since GFFF retention depends from first principles on particle size, Coulter counter measurements were performed in order to compare size distribution profiles with GFFF profiles. From such a comparison, GFFF was shown to be able to reveal differences in yeast cells other than size. This could make use of GFFF for screening different varieties of wine-making yeast towards future quality assessment procedures based on a possible correlation between yeast cell morphology indexes and quality indexes.

  15. Thermal modeling in an engine cooling system to control coolant flow for fuel consumption improvement

    NASA Astrophysics Data System (ADS)

    Park, Sangki; Woo, Seungchul; Kim, Minho; Lee, Kihyung

    2016-09-01

    The design and evaluation of engine cooling and lubrication systems is generally based on real vehicle tests. Our goal here was to establish an engine heat balance model based on mathematical and interpretive analysis of each element of a passenger diesel engine cooling system using a 1-D numerical model. The purpose of this model is to determine ways of optimizing the cooling and lubrication components of an engine and then to apply these methods to actual cooling and lubrication systems of engines that will be developed in the future. Our model was operated under the New European Driving Cycle (NEDC) mode conditions, which represent the fuel economy evaluation mode in Europe. The flow rate of the cooling system was controlled using a control valve. Our results showed that the fuel efficiency was improved by as much as 1.23 %, cooling loss by 1.35 %, and friction loss by 2.21 % throughout NEDC modes by modification of control conditions.

  16. Probabilistic power flow using improved Monte Carlo simulation method with correlated wind sources

    NASA Astrophysics Data System (ADS)

    Bie, Pei; Zhang, Buhan; Li, Hang; Deng, Weisi; Wu, Jiasi

    2017-01-01

    Probabilistic Power Flow (PPF) is a very useful tool for power system steady-state analysis. However, the correlation among different random injection power (like wind power) brings great difficulties to calculate PPF. Monte Carlo simulation (MCS) and analytical methods are two commonly used methods to solve PPF. MCS has high accuracy but is very time consuming. Analytical method like cumulants method (CM) has high computing efficiency but the cumulants calculating is not convenient when wind power output does not obey any typical distribution, especially when correlated wind sources are considered. In this paper, an Improved Monte Carlo simulation method (IMCS) is proposed. The joint empirical distribution is applied to model different wind power output. This method combines the advantages of both MCS and analytical method. It not only has high computing efficiency, but also can provide solutions with enough accuracy, which is very suitable for on-line analysis.

  17. Addition of a fracture risk assessment to a coordinator's role improved treatment rates within 6 months of screening in a fragility fracture screening program.

    PubMed

    Beaton, D E; Vidmar, M; Pitzul, K B; Sujic, R; Rotondi, N K; Bogoch, E R; Sale, J E M; Jain, R; Weldon, J

    2017-03-01

    We evaluated the impact of a more intensive version of an existing post-fracture coordinator-based fracture prevention program and found that the addition of a full-risk assessment improved treatment rates. These findings provide additional support for more intensive programs aimed at reducing the risk of re-fractures.

  18. N-doped TiO2 Nanotubes as an Effective Additive to Improve the Catalytic Capability of Methanol Oxidation for Pt/Graphene Nanocomposites

    PubMed Central

    Wang, Xiaohua; Li, Yueming; Liu, Shimin; Zhang, Long

    2016-01-01

    N-doped TiO2 nanotubes have been prepared as additives to improve the catalytic capability of Pt/graphene composites in methanol oxidation reactions. Electrochemical experiments show that the catalytic performance of Pt/graphene composites has been greatly improved by the introduction of N-doped TiO2 nanotubes.

  19. VEGF improves myocardial blood flow but produces EDRF-mediated hypotension in porcine hearts.

    PubMed

    Hariawala, M D; Horowitz, J R; Esakof, D; Sheriff, D D; Walter, D H; Keyt, B; Isner, J M; Symes, J F

    1996-06-01

    Several recent studies have demonstrated the potential for improving myocardial perfusion by the continuous administration of angiogenic growth factors. Studies in our laboratory have shown that a single intraarterial or intravenous bolus of the endothelial cell specific mitogen vascular endothelial growth factor (VEGF) can significantly improve perfusion in a rabbit ischemic limb model. To test the efficacy of this therapeutic approach in chronic myocardial ischemia, 18 Yorkshire pigs underwent a left thoracotomy followed by placement of an ameroid constrictor around the proximal circumflex coronary artery. Gradual occlusion of the artery (26 +/- 4 days) was accompanied by identifiable hypokinesis of the posterolateral wall of the left ventricle (2D echo). Thirty days postoperatively, rhVEGF(165) (2 mg; n = 8) or saline (n = 10) was administered directly into the left coronary ostium. Postadenosine myocardial perfusion studies using colored microspheres 30 days later demonstrated superior blood flow in the ischemic zone of the VEGF-treated hearts (ischemic/normal ratio 1.09 vs 0.97, P < 0.05) compared with those receiving saline injection. Four of eight VEGF-treated animals succumbed, however, to severe hypotension following VEGF administration. Therefore 500 micrograms of VEGF were administered intracoronary to five normal pigs. A significant drop in mean arterial pressure (-44.4 +/- 3.2%, P < 0.05 vs baseline) and peripheral resistance (-13.2 +/- 4.5%, P < 0.05 vs baseline) was accompanied by increased heart rate. IV administration of N(omega)-nitro-L-arginine (L-NNA), an EDRF inhibitor, restored blood pressure to baseline. We conclude that a single intracoronary bolus of VEGF is capable of significantly augmenting flow to collateral-dependent ischemic myocardium. The associated hypotension appears to be EDRF-mediated. Further studies are needed to define the best dose and route of administration of VEGF for the treatment of coronary insufficiency.

  20. Lean techniques for the improvement of patients’ flow in emergency department

    PubMed Central

    Chan, HY; Lo, SM; Lee, LLY; Lo, WYL; Yu, WC; Wu, YF; Ho, ST; Yeung, RSD; Chan, JTS

    2014-01-01

    BACKGROUND: Emergency departments (EDs) face problems with overcrowding, access block, cost containment, and increasing demand from patients. In order to resolve these problems, there is rising interest to an approach called “lean” management. This study aims to (1) evaluate the current patient flow in ED, (2) to identify and eliminate the non-valued added process, and (3) to modify the existing process. METHODS: It was a quantitative, pre- and post-lean design study with a series of lean management work implemented to improve the admission and blood result waiting time. These included structured re-design process, priority admission triage (PAT) program, enhanced communication with medical department, and use of new high sensitivity troponin-T (hsTnT) blood test. Triage waiting time, consultation waiting time, blood result time, admission waiting time, total processing time and ED length of stay were compared. RESULTS: Among all the processes carried out in ED, the most time consuming processes were to wait for an admission bed (38.24 minutes; SD 66.35) and blood testing result (mean 52.73 minutes, SD 24.03). The triage waiting time and end waiting time for consultation were significantly decreased. The admission waiting time of emergency medical ward (EMW) was significantly decreased from 54.76 minutes to 24.45 minutes after implementation of PAT program (P<0.05). CONCLUSION: The application of lean management can improve the patient flow in ED. Acquiescence to the principle of lean is crucial to enhance high quality emergency care and patient satisfaction. PMID:25215143

  1. Optic flow improves adaptability of spatiotemporal characteristics during split-belt locomotor adaptation with tactile stimulation

    PubMed Central

    Anthony Eikema, Diderik Jan A.; Chien, Jung Hung; Stergiou, Nicholas; Myers, Sara A.; Scott-Pandorf, Melissa M.; Bloomberg, Jacob J.; Mukherjee, Mukul

    2015-01-01

    Human locomotor adaptation requires feedback and feed-forward control processes to maintain an appropriate walking pattern. Adaptation may require the use of visual and proprioceptive input to decode altered movement dynamics and generate an appropriate response. After a person transfers from an extreme sensory environment and back, as astronauts do when they return from spaceflight, the prolonged period required for re-adaptation can pose a significant burden. In our previous paper, we showed that plantar tactile vibration during a split-belt adaptation task did not interfere with the treadmill adaptation however, larger overground transfer effects with a slower decay resulted. Such effects, in the absence of visual feedback (of motion) and perturbation of tactile feedback, is believed to be due to a higher proprioceptive gain because, in the absence of relevant external dynamic cues such as optic flow, reliance on body-based cues is enhanced during gait tasks through multisensory integration. In this study we therefore investigated the effect of optic flow on tactile stimulated split-belt adaptation as a paradigm to facilitate the sensorimotor adaptation process. Twenty healthy young adults, separated into two matched groups, participated in the study. All participants performed an overground walking trial followed by a split-belt treadmill adaptation protocol. The tactile group (TC) received vibratory plantar tactile stimulation only, whereas the virtual reality and tactile group (VRT) received an additional concurrent visual stimulation: a moving virtual corridor, inducing perceived self-motion. A post-treadmill overground trial was performed to determine adaptation transfer. Interlimb coordination of spatiotemporal and kinetic variables was quantified using symmetry indices, and analyzed using repeated-measures ANOVA. Marked changes of step length characteristics were observed in both groups during split-belt adaptation. Stance and swing time symmetry were

  2. Landscape and flow metrics affecting the distribution of a federally-threatened fish: Improving management, model fit, and model transferability

    USGS Publications Warehouse

    Brewer, Shannon K.; Worthington, Thomas A.; Zhang, Tianjioa; Logue, Daniel R.; Mittelstet, Aaron R.

    2016-01-01

    Truncated distributions of pelagophilic fishes have been observed across the Great Plains of North America, with water use and landscape fragmentation implicated as contributing factors. Developing conservation strategies for these species is hindered by the existence of multiple competing flow regime hypotheses related to species persistence. Our primary study objective was to compare the predicted distributions of one pelagophil, the Arkansas River Shiner Notropis girardi, constructed using different flow regime metrics. Further, we investigated different approaches for improving temporal transferability of the species distribution model (SDM). We compared four hypotheses: mean annual flow (a baseline), the 75th percentile of daily flow, the number of zero-flow days, and the number of days above 55th percentile flows, to examine the relative importance of flows during the spawning period. Building on an earlier SDM, we added covariates that quantified wells in each catchment, point source discharges, and non-native species presence to a structured variable framework. We assessed the effects on model transferability and fit by reducing multicollinearity using Spearman’s rank correlations, variance inflation factors, and principal component analysis, as well as altering the regularization coefficient (β) within MaxEnt. The 75th percentile of daily flow was the most important flow metric related to structuring the species distribution. The number of wells and point source discharges were also highly ranked. At the default level of β, model transferability was improved using all methods to reduce collinearity; however, at higher levels of β, the correlation method performed best. Using β = 5 provided the best model transferability, while retaining the majority of variables that contributed 95% to the model. This study provides a workflow for improving model transferability and also presents water-management options that may be considered to improve the

  3. Improved Predictions of Carbon Tetrachloride Contaminant Flow and Transport: Implementation of Kinetic Volatilization and Multicomponent NAPL Behavior

    SciTech Connect

    Oostrom, Martinus; Zhang, Z. F.; Freedman, Vicky L.; Tartakovsky, Guzel D.

    2008-09-29

    Carbon tetrachloride (CT) was discharged to waste sites that are included in the 200-PW-1 Operable Unit in Hanford 200 West Area. Fluor Hanford, Inc. is conducting a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial investigation/feasibility study (RI/FS) for the 200-PW-1 Operable Unit. The RI/FS process and remedial investigations for the 200-PW-1, 200 PW-3, and 200-PW-6 Operable Units are described in the Plutonium/Organic-Rich Process Condensate/Process Waste Groups Operable Unit RI/FS Work Plan. As part of this overall effort, Pacific Northwest National Laboratory (PNNL) was contracted to improve the STOMP simulator (White and Oostrom, 2006) by incorporating kinetic volatilization of nonaqueous phase liquids (NAPL) and multicomponent flow and transport. This work supports the U.S. Department of Energy's (DOE's) efforts to characterize the nature and distribution of CT in the 200 West Area and subsequently select an appropriate final remedy. Previous numerical simulation results with the STOMP simulator have overestimated the effect of soil vapor extraction (SVE) on subsurface CT, showing rapid removal of considerably more CT than has actually been recovered so far. These previous multiphase simulations modeled CT mass transfer between phases based on equilibrium partitioning. Equilibrium volatilization can overestimate volatilization because mass transfer limitations present in the field are not considered. Previous simulations were also conducted by modeling the NAPL as a single component, CT. In reality, however, the NAPL mixture disposed of at the Hanford site contained several non-volatile and nearly insoluble organic components, resulting in time-variant fluid properties as the CT component volatilized or dissolved over time. Simulation of CT removal from a DNAPL mixture using single-component DNAPL properties typically leads to an overestimation of CT removal. Other possible reasons for the discrepancy between

  4. Minimizing ED Waiting Times and Improving Patient Flow and Experience of Care.

    PubMed

    Sayah, Assaad; Rogers, Loni; Devarajan, Karthik; Kingsley-Rocker, Lisa; Lobon, Luis F

    2014-01-01

    We conducted a pre- and postintervention analysis to assess the impact of a process improvement project at the Cambridge Hospital ED. Through a comprehensive and collaborative process, we reengineered the emergency patient experience from arrival to departure. The ED operational changes have had a significant positive impact on all measured metrics. Ambulance diversion decreased from a mean of 148 hours per quarter before changes in July 2006 to 0 hours since April 2007. ED total length of stay decreased from a mean of 204 minutes before the changes to 132 minutes. Press Ganey patient satisfaction scores rose from the 12th percentile to the 59th percentile. ED patient volume grew by 11%, from a mean of 7,221 patients per quarter to 8,044 patients per quarter. Compliance with ED specific quality core measures improved from a mean of 71% to 97%. The mean rate of ED patients that left without being seen (LWBS) dropped from 4.1% to 0.9%. Improving ED operational efficiency allowed us to accommodate increasing volume while improving the quality of care and satisfaction of the ED patients with minimal additional resources, space, or staffing.

  5. Minimizing ED Waiting Times and Improving Patient Flow and Experience of Care

    PubMed Central

    Rogers, Loni; Devarajan, Karthik; Lobon, Luis F.

    2014-01-01

    We conducted a pre- and postintervention analysis to assess the impact of a process improvement project at the Cambridge Hospital ED. Through a comprehensive and collaborative process, we reengineered the emergency patient experience from arrival to departure. The ED operational changes have had a significant positive impact on all measured metrics. Ambulance diversion decreased from a mean of 148 hours per quarter before changes in July 2006 to 0 hours since April 2007. ED total length of stay decreased from a mean of 204 minutes before the changes to 132 minutes. Press Ganey patient satisfaction scores rose from the 12th percentile to the 59th percentile. ED patient volume grew by 11%, from a mean of 7,221 patients per quarter to 8,044 patients per quarter. Compliance with ED specific quality core measures improved from a mean of 71% to 97%. The mean rate of ED patients that left without being seen (LWBS) dropped from 4.1% to 0.9%. Improving ED operational efficiency allowed us to accommodate increasing volume while improving the quality of care and satisfaction of the ED patients with minimal additional resources, space, or staffing. PMID:24829802

  6. Measurement of emulsion flow in porous media: Improvements in heavy oil recovery

    NASA Astrophysics Data System (ADS)

    Bryan, J.; Wang, J.; Kantzas, A.

    2009-02-01

    Many heavy oil and bitumen reservoirs in the world are too small or thin for thermal enhanced oil recovery methods to be economic. In these fields, novel methods of less energy intensive, non-thermal technologies are required. Previous experience has shown that the injection of low concentrations of aqueous alkali-surfactant solutions into the reservoir can significantly improve the oil recovery, beyond that of waterflooding. This is due to the in-situ formation of emulsions, which plug off the water channels and lead to improved sweep efficiency in the reservoir. The proper control of these floods requires methods for monitoring the formation and effect of these emulsions. In this paper, the results of laboratory core floods are interpreted to demonstrate how the pressure and flow response can be related to the formation of these emulsions. A new technique (low field NMR) is also used to directly measure W/O emulsions in porous media. Finally, a numerical study is performed in order to demonstrate how the in-situ formation of emulsions can be simply represented in simulation software.

  7. Improvement in antioxidant functionality and shelf life of yukwa (fried rice snack) by turmeric (Curcuma longa L.) powder addition.

    PubMed

    Lim, Seung-Taik; Han, Jung-Ah

    2016-05-15

    The physico-chemical, oxidative and sensory characteristics of fried rice snack, yukwa with different amounts of turmeric powder (Curcuma longa) were investigated. The moisture content of the pallet ranged from 16.47% to 19.84%. After frying the pallet, a slight decrease in the degree of expansion was obtained with increasing turmeric powder content. The textural properties of yukwa were not changed until the turmeric powder content reached 5%; however, over 8% addition induced a decrease in the hardness and an increase in the crispiness. Oxidative deterioration was effectively inhibited by turmeric powder addition, and more turmeric powder in yukwa led to higher free radical scavenging activity. Based on the sensory characteristics, a 5% addition of turmeric powder was the most acceptable for the yukwa product. In the correlation results among variables, the moisture content of the pallet proved to be the most important factor for yukwa quality.

  8. Improved magneto-caloric effect of the Gd50Co50 metallic glass by minor Si addition

    NASA Astrophysics Data System (ADS)

    Tang, B. Z.; Yu, P.; Ding, D.; Wu, C.; Xia, L.

    2017-02-01

    In the present work, we studied the effect of minor Si addition on the magneto-caloric effect (MCE) of the Gd50Co50 metallic glass. The Gd50Co50-xSix (x=2, 5) as-spun ribbons show typical amorphous characteristics in structure and magneto-caloric behaviors. The peak values for the magnetic entropy change (-ΔSmpeak) of the Gd50Co50-xSix (x=0, 2, 5) metallic glasses increase significantly with the addition of Si. The mechanism for the enhanced MCE by minor addition of Si was investigated by revealing the relationship between -ΔSmpeak and the Curie temperature in the Gd-Co-based amorphous ribbons.

  9. Simultaneous determination of some food additives in soft drinks and other liquid foods by flow injection on-line dialysis coupled to high performance liquid chromatography.

    PubMed

    Kritsunankul, Orawan; Jakmunee, Jaroon

    2011-06-15

    Flow injection on-line dialysis was developed for sample pretreatment prior to the simultaneous determination of some food additives by high performance liquid chromatography (FID-HPLC). A liquid sample or mixed standard solution (900 μL) was injected into a donor stream (5%, w/v, sucrose) of FID system and was pushed further through a dialysis cell, while an acceptor solution (0.025 mol L(-1) phosphate buffer, pH 3.75) was held in the opposite side of the dialysis membrane. The dialysate was then flowed to an injection loop of the HPLC valve, where it was further injected into the HPLC system and analyzed under isocratic reverse-phase HPLC conditions and UV detection (230 nm). The order of elution of five food additives was acesulfame-K, saccharin, caffeine, benzoic acid and sorbic acid, respectively, with the analysis time of 14 min. On-line dialysis and HPLC analysis could be performed in parallel, providing sample throughput of 4.3h(-1). Dialysis efficiencies of five food additives were in ranges of 5-11%. Linear calibration graphs were in ranges of 10-100 mg L(-1) for acesulfame-K and saccharin, 10-250 mg L(-1) for benzoic acid and 10-500 mg L(-1) for caffeine and sorbic acid. Good precisions (RSD<5%) for all the additives were obtained. The proposed system was applied to soft drink and other liquid food samples. Acceptable percentage recoveries could be obtained by appropriate dilution of the sample before injecting into the system. The developed system has advantages of high degrees of automation for sample pretreatment, i.e., on-line sample separation and dilution and low consumption of chemicals and materials.

  10. Crystallization of calcium carbonate (CaCO3) in a flowing system: Influence of Cu2+ additives on induction time and crystalline phase transformation

    NASA Astrophysics Data System (ADS)

    Usmany, Y.; Putranto, W. A.; Bayuseno, A. P.; Muryanto, S.

    2016-04-01

    Scaling of calcium carbonate (CaCO3) is commonly found in piping systems in oil, gas, desalination and other chemical processes. The scale may create technical problems, leading to the reduction of heat transfer, increase of energy consumption and unscheduled equipment shutdown. This paper presents crystallization scaling experiments and evaluation of the effect of Cu2+ additives on the induction time and calcium carbonate transformation. The crystals precursors were prepared using equimolar of CaCl2 and Na2CO3 resulted in concentrations of 3000 ppm Ca2+ in the solution. The Cu2+ in amounts of 0, 1 and 10 ppm was separately added in the solution. The flow rates (20, 35, and 60 mL/min) and elevated temperatures (27, 35 and 45°C) were selected in the study. The induction time for crystallization of CaCO3 was observed by measuring the solution conductivity over time, while the phase transformation of calcium carbonate was examined by XRD method and SEM/EDX. It was found that the conductivity remained steady for a certain period reflecting to the induction time of crystal formation, and then decreased sharply afterwards,. The induction time was increased from 34 and 48 minutes in the presence of Cu additives (1 and 10 ppm), depending on the flow rates and temperature observed. In all the experiments, the Cu2+ addition leads to the reduction of mass of crystals. Apparently, the presence of Cu2+ could inhibit the CaCO3 crystallization. In the absence of Cu2+ and at elevated temperature, the crystals obtained were a mixture of vaterite and calcite. In the presence of Cu2+ and at elevated temperature, the crystals formed were aragonite and calcite. Here, the presence of Cu2+ additives might have controlled the crystal transformation of CaCO3.

  11. Inorganic nitrate ingestion improves vascular compliance but does not alter flow-mediated dilatation in healthy volunteers.

    PubMed

    Bahra, M; Kapil, V; Pearl, V; Ghosh, S; Ahluwalia, A

    2012-05-15

    Ingestion of inorganic nitrate elevates blood and tissue levels of nitrite via bioconversion in the entero-salivary circulation. Nitrite is converted to NO in the circulation, and it is this phenomenon that is thought to underlie the beneficial effects of inorganic nitrate in humans. Our previous studies have demonstrated that oral ingestion of inorganic nitrate decreases blood pressure and inhibits the transient endothelial dysfunction caused by ischaemia-reperfusion injury in healthy volunteers. However, whether inorganic nitrate might improve endothelial function per se in the absence of a pathogenic stimulus and whether this might contribute to the blood pressure lowering effects is yet unknown. We conducted a randomised, double-blind, crossover study in 14 healthy volunteers to determine the effects of oral inorganic nitrate (8 mmol KNO(3)) vs. placebo (8 mmol KCl) on endothelial function, measured by flow-mediated dilatation (FMD) of the brachial artery, prior to and 3h following capsule ingestion. In addition, blood pressure (BP) was measured and aortic pulse wave velocity (aPWV) determined. Finally, blood, saliva and urine samples were collected for chemiluminescence analysis of [nitrite] and [nitrate] prior to and 3h following interventions. Inorganic nitrate supplementation had no effect on endothelial function in healthy volunteers (6.9±1.1% pre- to 7.1±1.1% post-KNO(3)). Despite this, there was a significant elevation of plasma [nitrite] (0.4±0.1 μM pre- to 0.7±0.2 μM post-KNO(3), p<0.001). In addition these changes in [nitrite] were associated with a decrease in systolic BP (116.9±3.8mm Hg pre- vs. 112.1±3.4 mm Hg post-KNO(3), p<0.05) and aPWV (6.5±0.1 m/s pre- to 6.2±0.1 post-KNO(3), p<0.01). In contrast KCl capsules had no effect on any of the parameters measured. These findings demonstrate that although inorganic nitrate ingestion does not alter endothelial function per se, it does appear to improve blood flow, in combination with a

  12. Thermochemistry and Kinetics for Designer Molecules Additives to Energetic Materials for Improved Performance: Thermal Generation of Hydrazine

    DTIC Science & Technology

    2007-09-28

    Functional, Moller Plesset ab initio, and the CBS- QB3 (Complete Basis Set) computational chemistry methods. In each case the elimination of... QB3 calculation energies and by improving the the entropy S o (T) and heat capacity Cp(T) contributions from values further analysis of the internal

  13. Improving the long-term cycling performance of lithium-ion batteries at elevated temperature with electrolyte additives

    NASA Astrophysics Data System (ADS)

    Xia, Jian; Ma, Lin; Dahn, J. R.

    2015-08-01

    The effects of vinylene carbonate-based and prop-1-ene-1,3-sultone-based electrolyte additives on the cycling behavior of Li[Ni1/3Mn1/3Co1/3]O2/graphite pouch type cells at elevated temperature have been systematically studied. Capacity fade during cycling, charge-transfer resistance before and after cycling as well as gas evolution during formation and also during cycling were examined and compared. For vinylene carbonate-based additive blends, only 3% vinylene carbonate, 2% vinylene carbonate + 1% 1,3,2-dioxathiolane-2,2-dioxide + 1% tris(trimethylsilyl) phosphite or 2% vinylene carbonate + 1% methylene methyl disulfonate + 1% tris(trimethylsilyl) phosphite showed less capacity fade than 2% vinylene carbonate alone. Cells with all of these vinylene carbonate-based electrolyte additive blends lost more than 20% of their initial capacity after ∼1000 cycles at 55 °C and all the vinylene carbonate-based cells swelled more than 10% of their initial volume during this test. Cells containing all prop-1-ene-1,3-sultone-based additive blends generally produced much less gas than the vinylene carbonate-based blends. Many cells containing prop-1-ene-1,3-sultone-based additive blends lost less than 20% of their initial capacity after 1000 cycles. Moreover, the impedance of these prop-1-ene-1,3-sultone-based electrolytes decreased after long-term cycling. These results suggest that prop-1-ene-1,3-sultone-based electrolytes are more useful than vinylene carbonate-based electrolytes at high temperatures in Li[Ni1/3Mn1/3Co1/3]O2/graphite cells.

  14. Using flow cytometry to estimate pollen DNA content: improved methodology and applications

    PubMed Central

    Kron, Paul; Husband, Brian C.

    2012-01-01

    Background and Aims Flow cytometry has been used to measure nuclear DNA content in pollen, mostly to understand pollen development and detect unreduced gametes. Published data have not always met the high-quality standards required for some applications, in part due to difficulties inherent in the extraction of nuclei. Here we describe a simple and relatively novel method for extracting pollen nuclei, involving the bursting of pollen through a nylon mesh, compare it with other methods and demonstrate its broad applicability and utility. Methods The method was tested across 80 species, 64 genera and 33 families, and the data were evaluated using established criteria for estimating genome size and analysing cell cycle. Filter bursting was directly compared with chopping in five species, yields were compared with published values for sonicated samples, and the method was applied by comparing genome size estimates for leaf and pollen nuclei in six species. Key Results Data quality met generally applied standards for estimating genome size in 81 % of species and the higher best practice standards for cell cycle analysis in 51 %. In 41 % of species we met the most stringent criterion of screening 10 000 pollen grains per sample. In direct comparison with two chopping techniques, our method produced better quality histograms with consistently higher nuclei yields, and yields were higher than previously published results for sonication. In three binucleate and three trinucleate species we found that pollen-based genome size estimates differed from leaf tissue estimates by 1·5 % or less when 1C pollen nuclei were used, while estimates from 2C generative nuclei differed from leaf estimates by up to 2·5 %. Conclusions The high success rate, ease of use and wide applicability of the filter bursting method show that this method can facilitate the use of pollen for estimating genome size and dramatically improve unreduced pollen production estimation with flow cytometry. PMID

  15. An Improved Flow Cytometry Method For Precise Quantitation Of Natural-Killer Cell Activity

    NASA Technical Reports Server (NTRS)

    Crucian, Brian; Nehlsen-Cannarella, Sandra; Sams, Clarence

    2006-01-01

    The ability to assess NK cell cytotoxicity using flow cytometry has been previously described and can serve as a powerful tool to evaluate effector immune function in the clinical setting. Previous methods used membrane permeable dyes to identify target cells. The use of these dyes requires great care to achieve optimal staining and results in a broad spectral emission that can make multicolor cytometry difficult. Previous methods have also used negative staining (the elimination of target cells) to identify effector cells. This makes a precise quantitation of effector NK cells impossible due to the interfering presence of T and B lymphocytes, and the data highly subjective to the variable levels of NK cells normally found in human peripheral blood. In this study an improved version of the standard flow cytometry assay for NK activity is described that has several advantages of previous methods. Fluorescent antibody staining (CD45FITC) is used to positively identify target cells in place of membranepermeable dyes. Fluorescent antibody staining of target cells is less labor intensive and more easily reproducible than membrane dyes. NK cells (true effector lymphocytes) are also positively identified by fluorescent antibody staining (CD56PE) allowing a simultaneous absolute count assessment of both NK cells and target cells. Dead cells are identified by membrane disruption using the DNA intercalating dye PI. Using this method, an exact NK:target ratio may be determined for each assessment, including quantitation of NK target complexes. Backimmunoscatter gating may be used to track live vs. dead Target cells via scatter properties. If desired, NK activity may then be normalized to standardized ratios for clinical comparisons between patients, making the determination of PBMC counts or NK cell percentages prior to testing unnecessary. This method provides an exact cytometric determination of NK activity that highly reproducible and may be suitable for routine use in the

  16. Improved design and optimization of subsurface flow constructed wetlands and sand filters

    NASA Astrophysics Data System (ADS)

    Brovelli, A.; Carranza-Díaz, O.; Rossi, L.; Barry, D. A.

    2010-05-01

    Subsurface flow constructed wetlands and sand filters are engineered systems capable of eliminating a wide range of pollutants from wastewater. These devices are easy to operate, flexible and have low maintenance costs. For these reasons, they are particularly suitable for small settlements and isolated farms and their use has substantially increased in the last 15 years. Furthermore, they are also becoming used as a tertiary - polishing - step in traditional treatment plants. Recent work observed that research is however still necessary to understand better the biogeochemical processes occurring in the porous substrate, their mutual interactions and feedbacks, and ultimately to identify the optimal conditions to degrade or remove from the wastewater both traditional and anthropogenic recalcitrant pollutants, such as hydrocarbons, pharmaceuticals, personal care products. Optimal pollutant elimination is achieved if the contact time between microbial biomass and the contaminated water is sufficiently long. The contact time depends on the hydraulic residence time distribution (HRTD) and is controlled by the hydrodynamic properties of the system. Previous reports noted that poor hydrodynamic behaviour is frequent, with water flowing mainly through preferential paths resulting in a broad HRTD. In such systems the flow rate must be decreased to allow a sufficient proportion of the wastewater to experience the minimum residence time. The pollutant removal efficiency can therefore be significantly reduced, potentially leading to the failure of the system. The aim of this work was to analyse the effect of the heterogeneous distribution of the hydraulic properties of the porous substrate on the HRTD and treatment efficiency, and to develop an improved design methodology to reduce the risk of system failure and to optimize existing systems showing poor hydrodynamics. Numerical modelling was used to evaluate the effect of substrate heterogeneity on the breakthrough curves of

  17. An improved optical flow tracking technique for real-time MR-guided beam therapies in moving organs

    NASA Astrophysics Data System (ADS)

    Zachiu, C.; Papadakis, N.; Ries, M.; Moonen, C.; de Senneville, B. Denis

    2015-12-01

    Magnetic resonance (MR) guided high intensity focused ultrasound and external beam radiotherapy interventions, which we shall refer to as beam therapies/interventions, are promising techniques for the non-invasive ablation of tumours in abdominal organs. However, therapeutic energy delivery in these areas becomes challenging due to the continuous displacement of the organs with respiration. Previous studies have addressed this problem by coupling high-framerate MR-imaging with a tracking technique based on the algorithm proposed by Horn and Schunck (H and S), which was chosen due to its fast convergence rate and highly parallelisable numerical scheme. Such characteristics were shown to be indispensable for the real-time guidance of beam therapies. In its original form, however, the algorithm is sensitive to local grey-level intensity variations not attributed to motion such as those that occur, for example, in the proximity of pulsating arteries. In this study, an improved motion estimation strategy which reduces the impact of such effects is proposed. Displacements are estimated through the minimisation of a variation of the H and S functional for which the quadratic data fidelity term was replaced with a term based on the linear L1norm, resulting in what we have called an L2-L1 functional. The proposed method was tested in the livers and kidneys of two healthy volunteers under free-breathing conditions, on a data set comprising 3000 images equally divided between the volunteers. The results show that, compared to the existing approaches, our method demonstrates a greater robustness to local grey-level intensity variations introduced by arterial pulsations. Additionally, the computational time required by our implementation make it compatible with the work-flow of real-time MR-guided beam interventions. To the best of our knowledge this study was the first to analyse the behaviour of an L1-based optical flow functional in an applicative context: real-time MR

  18. WETTABILITY ALTERATION OF POROUS MEDIA TO GAS-WETTING FOR IMPROVING PRODUCTIVITY AND INJECTIVITY IN GAS-LIQUID FLOWS

    SciTech Connect

    Abbas Firoozabadi

    2002-10-21

    The authors have performed a number of imbibition tests with the treated and untreated cores in nC{sub 10}, nC{sub 14}, and nC{sub 16} and a natural gas condensate liquid. Imbibition tests for nC{sub 14} and nC{sub 16} were also carried out at elevated temperatures of 100 C and 140 C. An experimental polymer synthesized for the purpose of this project was used in core treatment. Imbibition results are very promising and imply liquid condensate mobility enhancement in the treated core. They also performed flow tests to quantify the increase in well deliverability and to simulate flow under realistic field conditions. In the past we have performed extensive testing of wettability alteration in intermediate gas wetting for polymer FC759 at temperatures of 24 C and 90 C. The results were promising for the purpose of gas well deliverability improvement in gas condensate wells. We used FC759 to lower the surface energy of various rocks. The model fluids nC{sub 10}, and nC{sub 14} were used to represent condensate liquid, and air was used as the gas phase. A new (L-16349) polymer, which has been recently synthesized for the purpose of the project, was used in the work to be presented here. L-16349 is a water-soluble fluorochemical polymer, with low order, neutral PH and very low volatile organic compound (VOC < 9.1 g/l). It is light yellow in appearance and density in 25% solution is 1.1 g/cc. Polymer L-16349 is very safe from environmental considerations and it is economical for our purpose. In this work, in addition to nC{sub 10}, and nC{sub 14}, we used two other liquids nC{sub 16}, and a liquid condensate in order to study the effect of wettability alteration with a broader range of fluids.

  19. An improved UPLC method for the detection of undeclared horse meat addition by using myoglobin as molecular marker.

    PubMed

    Di Giuseppe, Antonella M A; Giarretta, Nicola; Lippert, Martina; Severino, Valeria; Di Maro, Antimo

    2015-02-15

    In 2013, following the scandal of the presence of undeclared horse meat in various processed beef products across the Europe, several researches have been undertaken for the safety of consumer health. In this framework, an improved UPLC separation method has been developed to detect the presence of horse myoglobin in raw meat samples. The separation of both horse and beef myoglobins was achieved in only seven minutes. The methodology was improved by preparing mixtures with different composition percentages of horse and beef meat. By using myoglobin as marker, low amounts (0.50mg/0.50g, w/w; ∼0.1%) of horse meat can be detected and quantified in minced raw meat samples with high reproducibility and sensitivity, thus offering a valid alternative to conventional PCR techniques.

  20. Development of an improved rhodium catalyst for z-selective anti-markovnikov addition of carboxylic acids to terminal alkynes.

    PubMed

    Wei, Siping; Pedroni, Julia; Meißner, Antje; Lumbroso, Alexandre; Drexler, Hans-Joachim; Heller, Detlef; Breit, Bernhard

    2013-09-02

    To develop more active catalysts for the rhodium-catalyzed addition of carboxylic acids to terminal alkynes furnishing anti-Markovnikov Z enol esters, a thorough study of the rhodium complexes involved was performed. A number of rhodium complexes were characterized by NMR, ESI-MS, and X-ray analysis and applied as catalysts for the title reaction. The systematic investigations revealed that the presence of chloride ions decreased the catalyst activity. Conversely, generating and applying a mixture of two rhodium species, namely, [Rh(DPPMP)2][H(benzoate)2] (DPPMP=diphenylphosphinomethylpyridine) and [{Rh(COD)(μ2-benzoate)}2], provided a significantly more active catalyst. Furthermore, the addition of a catalytic amount of base (Cs2CO3) had an additional accelerating effect. This higher catalyst activity allowed the reaction time to be reduced from 16 to 1-4 h while maintaining high selectivity. Studies on the substrate scope revealed that the new catalysts have greater functional-group compatibility.

  1. Improvement of stability and carotenoids fraction of virgin olive oils by addition of microalgae Scenedesmus almeriensis extracts.

    PubMed

    Limón, Piedad; Malheiro, Ricardo; Casal, Susana; Acién-Fernández, F Gabriel; Fernández-Sevilla, José M; Rodrigues, Nuno; Cruz, Rebeca; Bermejo, Ruperto; Pereira, José Alberto

    2015-05-15

    Humans are not capable of synthesizing carotenoids de novo and thus, their presence in human tissues is entirely of dietary origin. Consumption of essential carotenoids is reduced due to the lower intake of fruits and vegetables. Microalgae are a good source of carotenoids that can be exploited. In the present work, carotenoids rich extracts from Scenedesmus almeriensis were added to extra-virgin olive oils at different concentrations (0.1 and 0.21 mg/mL) in order to enhance the consumption of these bioactives. Extracts brought changes in olive oils color, turning them orange-reddish. Quality of olive oils was improved, since peroxidation was inhibited. Olive oils fatty acids and tocopherols were not affected. β-carotene and lutein contents increase considerably, as well as oxidative stability, improving olive oils shelf-life and nutritional value. Inclusion of S. almeriensis extracts is a good strategy to improve and enhance the consumption of carotenoids, since olive oil consumption is increasing.

  2. The enhancement of cyclic electron flow around photosystem I improves the recovery of severely desiccated Porphyra yezoensis (Bangiales, Rhodophyta).

    PubMed

    Gao, Shan; Wang, Guangce

    2012-07-01

    Porphyra yezoensis, a representative species of intertidal macro-algae, is able to withstand periodic desiccation at low tide but is submerged in seawater at high tide. In this study, changes in photosynthetic electron flow in P. yezoensis during desiccation and re-hydration were investigated. The results suggested that the cyclic electron flow around photosystem I (PSI) increased significantly during desiccation, continued to operate at times of severe desiccation, and showed greater tolerance to desiccation than the electron flow around PSII. In addition, PSI activity in desiccated blades recovered faster than PSII activity during re-hydration. Even though linear electron flow was suppressed by DCMU [3-(3',4'-dichlorophenyl)-1,1-dimethylurea], cyclic electron flow could still be restored. This process was insensitive to antimycin A and could be suppressed by dibromothymoquinone (DBMIB). The prolonged dark treatment of blades reduced the speed in which the cyclic electron flow around PSI recovered, suggesting that stromal reductants, including NAD(P)H, played an important role in the donation of electrons to PSI and were the main cause of the rapid recovery of cyclic electron flow in desiccated blades during re-hydration. These results suggested that cyclic electron flow in P. yezoensis played a significant physiological role during desiccation and re-hydration and may be one of the most important factors allowing P. yezoensis blades to adapt to intertidal environments.

  3. Blood flow dynamic improvement with aneurysm repair detected by a patient-specific model of multiple aortic aneurysms.

    PubMed

    Sughimoto, Koichi; Takahara, Yoshiharu; Mogi, Kenji; Yamazaki, Kenji; Tsubota, Ken'ichi; Liang, Fuyou; Liu, Hao

    2014-05-01

    Aortic aneurysms may cause the turbulence of blood flow and result in the energy loss of the blood flow, while grafting of the dilated aorta may ameliorate these hemodynamic disturbances, contributing to the alleviation of the energy efficiency of blood flow delivery. However, evaluating of the energy efficiency of blood flow in an aortic aneurysm has been technically difficult to estimate and not comprehensively understood yet. We devised a multiscale computational biomechanical model, introducing novel flow indices, to investigate a single male patient with multiple aortic aneurysms. Preoperative levels of wall shear stress and oscillatory shear index (OSI) were elevated but declined after staged grafting procedures: OSI decreased from 0.280 to 0.257 (first operation) and 0.221 (second operation). Graftings may strategically counter the loss of efficient blood delivery to improve hemodynamics of the aorta. The energy efficiency of blood flow also improved postoperatively. Novel indices of pulsatile pressure index (PPI) and pulsatile energy loss index (PELI) were evaluated to characterize and quantify energy loss of pulsatile blood flow. Mean PPI decreased from 0.445 to 0.423 (first operation) and 0.359 (second operation), respectively; while the preoperative PELI of 0.986 dropped to 0.820 and 0.831. Graftings contributed not only to ameliorate wall shear stress or oscillatory shear index but also to improve efficient blood flow. This patient-specific modeling will help in analyzing the mechanism of aortic aneurysm formation and may play an important role in quantifying the energy efficiency or loss in blood delivery.

  4. Improving lateral-flow immunoassay (LFIA) diagnostics via biomarker enrichment for mHealth.

    PubMed

    Lai, James J; Stayton, Patrick S

    2015-01-01

    Optical detection technologies based on mobile devices can be utilized to enable many mHealth applications, including a reader for lateral-flow immunoassay (LFIA). However, an intrinsic challenge associated with LFIA for clinical diagnostics is the limitation in sensitivity. Therefore, rapid and simple specimen processing strategies can directly enable more sensitive LFIA by purifying and concentrating biomarkers. Here, a binary reagent system is presented for concentrating analytes from a larger volume specimen to improve the malaria LFIA's limit of detection (LOD). The biomarker enrichment process utilizes temperature-responsive gold-streptavidin conjugates, biotinylated antibodies, and temperature-responsive magnetic nanoparticles. The temperature-responsive gold colloids were synthesized by modifying the citrate-stabilized gold colloids with a diblock copolymer, containing a thermally responsive poly(N-isopropylacrylamide) (pNIPAAm) segment and a gold-binding block composed of NIPAAm-co-N,N-dimethylaminoethylacrylamide. The gold-streptavidin conjugates were synthesized by conjugating temperature-responsive gold colloids with streptavidin via covalent linkages using carbodiimide chemistry chemistry. The gold conjugates formed half-sandwiches, gold labeled biomarker, by complexing with biotinylated antibodies that were bound to Plasmodium falciparum histidine-rich protein 2 (PfHRP2), a malaria antigen. When a thermal stimulus was applied in conjunction with a magnetic field, the half-sandwiches and temperature-responsive magnetic nanoparticles that were both decorated with pNIPAAm formed large aggregates that were efficiently magnetically separated from human plasma. The binary reagent system was applied to a large volume (500 μL) specimen for concentrating biomarker 50-fold into a small volume and applied directly to an off-the-shelf malaria LFIA to improve the signal-to-noise ratio.

  5. Accuracy Maximization Analysis for Sensory-Perceptual Tasks: Computational Improvements, Filter Robustness, and Coding Advantages for Scaled Additive Noise

    PubMed Central

    Burge, Johannes

    2017-01-01

    Accuracy Maximization Analysis (AMA) is a recently developed Bayesian ideal observer method for task-specific dimensionality reduction. Given a training set of proximal stimuli (e.g. retinal images), a response noise model, and a cost function, AMA returns the filters (i.e. receptive fields) that extract the most useful stimulus features for estimating a user-specified latent variable from those stimuli. Here, we first contribute two technical advances that significantly reduce AMA’s compute time: we derive gradients of cost functions for which two popular estimators are appropriate, and we implement a stochastic gradient descent (AMA-SGD) routine for filter learning. Next, we show how the method can be used to simultaneously probe the impact on neural encoding of natural stimulus variability, the prior over the latent variable, noise power, and the choice of cost function. Then, we examine the geometry of AMA’s unique combination of properties that distinguish it from better-known statistical methods. Using binocular disparity estimation as a concrete test case, we develop insights that have general implications for understanding neural encoding and decoding in a broad class of fundamental sensory-perceptual tasks connected to the energy model. Specifically, we find that non-orthogonal (partially redundant) filters with scaled additive noise tend to outperform orthogonal filters with constant additive noise; non-orthogonal filters and scaled additive noise can interact to sculpt noise-induced stimulus encoding uncertainty to match task-irrelevant stimulus variability. Thus, we show that some properties of neural response thought to be biophysical nuisances can confer coding advantages to neural systems. Finally, we speculate that, if repurposed for the problem of neural systems identification, AMA may be able to overcome a fundamental limitation of standard subunit model estimation. As natural stimuli become more widely used in the study of psychophysical and

  6. Comparison of two live Bacillus species as feed additives for improving in vitro fermentation of cereal straws.

    PubMed

    Wang, Zuo; He, Zhixiong; Beauchemin, Karen A; Tang, Shaoxun; Zhou, Chuanshe; Han, Xuefeng; Wang, Min; Kang, Jinhe; Odongo, Nicholas E; Tan, Zhiliang

    2016-01-01

    This study was performed in a 2 × 4 factorial arrangement to explore and compare the effects of inclusion of two live Bacillus additives (B. licheniformis and B. subtilis) at four doses (0, 0.25 × 10(7), 0.50 × 10(7) and 0.75 × 10(7) colony-forming units (cfu)) on in vitro gas production kinetics, fiber degradation, methane production and ruminal fermentation characteristics of maize stover and rice straw by mixed rumen microorganisms in dairy cows. The pH, concentrations of ammonia nitrogen (NH3-N) and isovalerate were increased (P < 0.05), while the methane (CH4) production, ratio of acetate to propionate, and total volatile fatty acids (TVFA) concentration were decreased (P < 0.05) by the supplementation of B. licheniformis compared with that of B. subtilis. Adding B. licheniformis and B. subtilis raised (P < 0.05) or numerically raised the maximum gas production, while decreasing (P < 0.05) or numerically lowering pH and concentrations of most volatile fatty acids. The addition of B. licheniformis increased (P < 0.05) the NH3-N concentration but reduced CH4 production and ratio of acetate to propionate (P < 0.05), while the NH3 -N concentration was decreased (P < 0.05), and the CH4 production and ratio of acetate to propionate were increased by that of B. subtilis compared to the control. Results obtained in this research suggest that B. licheniformis would be preferred as a live Bacillus additive in comparison with B. subtilis, and its optimal dose should be 0.25 × 10(7) cfu/500 mg substrates.

  7. Ensemble Data Assimilation for Channel Flow Routing to Improve Operational Hydrologic Forecasting

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Lee, H.; Seo, D.; Brown, J.; Corby, R.; Howieson, T.

    2008-12-01

    Channel flow routing, which predicts hydrograph transformation as water moves downstream, is a critical step in operational forecasting of floods and water resources. Like hydrologic modeling for headwater basins, routing modeling involves many kinds of uncertainties arising from observational data and the model itself. In addition to in-channel transformations, routing must also consider uncertainties from less-than-well-known sources and sinks along the channel. Data assimilation holds large potential in accounting for these different uncertainties in a dynamically and statistically consistent way. In this presentation, we describe an application of ensemble data assimilation for a hydrologic channel routing model based on the variable three-parameter Muskingum method, in which we consider errors in the inflow and outflow observations, and uncertainties in the initial conditions and Muskingum parameters. For data assimilation, we adopt the Maximum Likelihood Ensemble Filter (or MLEF, Zupanski 2005), which combines the strengths of variational data assimilation and ensemble filtering techniques. Results from applications to selected river sections in Texas in the WGRFC's service area will be presented, along with issues from research and operational perspectives.

  8. Improved hydrophilic interaction chromatography LC/MS of heparinoids using a chip with postcolumn makeup flow.

    PubMed

    Staples, Gregory O; Naimy, Hicham; Yin, Hongfeng; Kileen, Kevin; Kraiczek, Karsten; Costello, Catherine E; Zaia, Joseph

    2010-01-15

    Heparan sulfate (HS) and heparin are linear, heterogeneous carbohydrates of the glycosaminoglycan (GAG) family that are modified by N-acetylation, N-sulfation, O-sulfation, and uronic acid epimerization. HS interacts with growth factors in the extracellular matrix, thereby modulating signaling pathways that govern cell growth, development, differentiation, proliferation, and adhesion. High-performance liquid chromatography (HPLC)-chip-based hydrophilic interaction liquid chromatography/mass spectrometry has emerged as a method for analyzing the domain structure of GAGs. However, analysis of highly sulfated GAG structures decasaccharide or larger in size has been limited by spray instability in the negative-ion mode. This report demonstrates that addition of postcolumn makeup flow to the amide-HPLC-chip configuration permits robust and reproducible analysis of extended GAG domains (up to degree of polymerization 18) from HS and heparin. This platform provides quantitative information regarding the oligosaccharide profile, degree of sulfation, and nonreducing chain termini. It is expected that this technology will enable quantitative, comparative glycomics profiling of extended GAG oligosaccharide domains of functional interest.

  9. Improved two-equation k-omega turbulence models for aerodynamic flows

    NASA Technical Reports Server (NTRS)

    Menter, Florian R.

    1992-01-01

    Two new versions of the k-omega two-equation turbulence model will be presented. The new Baseline (BSL) model is designed to give results similar to those of the original k-omega model of Wilcox, but without its strong dependency on arbitrary freestream values. The BSL model is identical to the Wilcox model in the inner 50 percent of the boundary-layer but changes gradually to the high Reynolds number Jones-Launder k-epsilon model (in a k-omega formulation) towards the boundary-layer edge. The new model is also virtually identical to the Jones-Lauder model for free shear layers. The second version of the model is called Shear-Stress Transport (SST) model. It is based on the BSL model, but has the additional ability to account for the transport of the principal shear stress in adverse pressure gradient boundary-layers. The model is based on Bradshaw's assumption that the principal shear stress is proportional to the turbulent kinetic energy, which is introduced into the definition of the eddy-viscosity. Both models are tested for a large number of different flowfields. The results of the BSL model are similar to those of the original k-omega model, but without the undesirable freestream dependency. The predictions of the SST model are also independent of the freestream values and show excellent agreement with experimental data for adverse pressure gradient boundary-layer flows.

  10. Methods to improve traffic flow and noise exposure estimation on minor roads.

    PubMed

    Morley, David W; Gulliver, John

    2016-09-01

    Address-level estimates of exposure to road traffic noise for epidemiological studies are dependent on obtaining data on annual average daily traffic (AADT) flows that is both accurate and with good geographical coverage. National agencies often have reliable traffic count data for major roads, but for residential areas served by minor roads, especially at national scale, such information is often not available or incomplete. Here we present a method to predict AADT at the national scale for minor roads, using a routing algorithm within a geographical information system (GIS) to rank roads by importance based on simulated journeys through the road network. From a training set of known minor road AADT, routing importance is used to predict AADT on all UK minor roads in a regression model along with the road class, urban or rural location and AADT on the nearest major road. Validation with both independent traffic counts and noise measurements show that this method gives a considerable improvement in noise prediction capability when compared to models that do not give adequate consideration to minor road variability (Spearman's rho. increases from 0.46 to 0.72). This has significance for epidemiological cohort studies attempting to link noise exposure to adverse health outcomes.

  11. An Improved Method for High-throughput Discrimination and Enumeration of Sedimentary Cells Using Flow Cytometry

    NASA Astrophysics Data System (ADS)

    Morono, Y.; Kallmeyer, J.; Terada, T.; Inagaki, F.; IODP Expedition 329 Shipboard Science Party

    2011-12-01

    Detection and enumeration of microbial life in marine subsurface environments provides primary information on the extent and habitability of the Earth's biosphere. Flow cytometry (FCM) is a powerful tool for identifying and enumerating fluorescence-stained cells with high throughput, using fluorescent intensity, range of wavelength, and cell size. FCM is widely used in medical sciences and aquatic microbial ecology. However, mineral grains and difficulties in distinguishing between life cells and non-specific background fluorescence prevented FCM to be applied for counting microbial cells in sediment or rock samples. SYBR Green I-stained cells can be distinguished from non-biological background signals based on differences in their fluorescence spectra. Here we extended this technique to FCM analysis by modifying the cell detachment protocol using a density gradient method, and then standardized an FCM cell counting method for various types of marine subsurface sediments. Microbial cells in sediment samples could effectively be detached and analyzed discriminatively with FCM. The high capacity of FCM to count particles (up to 10,000 cells/sec) and its high sensitivity will provide information about microbial cell abundance at high spatial resolution and with unprecedented accuracy. This improved cell count method will be useful to evaluate samples with high depth resolution, including narrow geochemical and geological interfaces as potential specific microbial niches, and may even help to asses very low population densities at the fringe of the biosphere.

  12. Analysing the information flow between financial time series . An improved estimator for transfer entropy

    NASA Astrophysics Data System (ADS)

    Marschinski, R.; Kantz, H.

    2002-11-01

    Following the recently introduced concept of transfer entropy, we attempt to measure the information flow between two financial time series, the Dow Jones and DAX stock index. Being based on Shannon entropies, this model-free approach in principle allows us to detect statistical dependencies of all types, i.e. linear and nonlinear temporal correlations. However, when available data is limited and the expected effect is rather small, a straightforward implementation suffers badly from misestimation due to finite sample effects, making it basically impossible to assess the significance of the obtained values. We therefore introduce a modified estimator, called effective transfer entropy, which leads to improved results in such conditions. In the application, we then manage to confirm an information transfer on a time scale of one minute between the two financial time series. The different economic impact of the two indices is also recovered from the data. Numerical results are then interpreted on one hand as capability of one index to explain future observations of the other, and on the other hand within terms of coupling strengths in the framework of a bivariate autoregressive stochastic model. Evidence is given for a nonlinear character of the coupling between Dow Jones and DAX.

  13. Improving variational mass-consistent models of hydrodynamic flows via boundary conditions

    NASA Astrophysics Data System (ADS)

    Núñez, M. A.

    2012-04-01

    Variational mass-consistent models for the velocity field v have been used by mesoscale meteorological community to modeling the wind field from an observed field v 0 in a bounded region Ω with boundary Γ. Variational calculus reduces the problem to the solution of an elliptic equation for a Lagrange multiplier λ subject to Dirichlet Boundary Condition (DBC) on flow-through boundaries. In this work, it is shown that DBC decreases the regularity of λ and this in turn decreases the accuracy with which the velocity field satisfies the mass-balance. The boundary condition (BC) v · n = v T · ngiven by the true field v T on the whole boundary Γ, leads only to a Neumann boundary condition (NBC) for λ. Approximations of this BC are studied. Analytic and numerical results show that the velocity field U 0 obtained from v 0 by direct integration of the continuity equation, yields a NBC that improves significantly the fields obtained with DBC's.

  14. The improved mechanical properties of β-CaSiO3 bioceramics with Si3N4 addition.

    PubMed

    Pan, Ying; Zuo, Kaihui; Yao, Dongxu; Yin, Jinwei; Xin, Yunchuan; Xia, Yongfeng; Liang, Hanqin; Zeng, Yuping

    2015-03-01

    The motivation of this study is to investigate the effect of Si3N4 addition on the sinterability of β-CaSiO3 ceramics. β-CaSiO3 ceramics with different content of Si3N4 were prepared at the sintering temperature ranging from 1000°C to 1150°C. The results showed that Si3N4 can be successfully used as sintering additive by being oxidized to form SiO2. The β-CaSiO3 ceramics with 3wt% Si3N4 sintered at 1100°C revealed flexural strength, hardness and fracture toughness of 157.2MPa, 4.4GPa and 2.3MPam(1/2) respectively, which was much higher than that of pure β-CaSiO3 ceramics (41.1MPa, 1.0GPa, 1.1MPam(1/2)). XRD analysis and SEM observation indicated that the main phase maintained to be β-phase after sintering.

  15. Improved bioactivity of antimicrobial peptides by addition of amino-terminal copper and nickel (ATCUN) binding motifs.

    PubMed

    Libardo, M Daben; Cervantes, Jorge L; Salazar, Juan C; Angeles-Boza, Alfredo M

    2014-08-01

    Antimicrobial peptides (AMPs) are promising candidates to help circumvent antibiotic resistance, which is an increasing clinical problem. Amino-terminal copper and nickel (ATCUN) binding motifs are known to actively form reactive oxygen species (ROS) upon metal binding. The combination of these two peptidic constructs could lead to a novel class of dual-acting antimicrobial agents. To test this hypothesis, a set of ATCUN binding motifs were screened for their ability to induce ROS formation, and the most potent were then used to modify AMPs with different modes of action. ATCUN binding motif-containing derivatives of anoplin (GLLKRIKTLL-NH2), pro-apoptotic peptide (PAP; KLAKLAKKLAKLAK-NH2), and sh-buforin (RAGLQFPVGRVHRLLRK-NH2) were synthesized and found to be more active than the parent AMPs against a panel of clinically relevant bacteria. The lower minimum inhibitory concentration (MIC) values for the ATCUN-anoplin peptides are attributed to the higher pore-forming activity along with their ability to cause ROS-induced membrane damage. The addition of the ATCUN motifs to PAP also increases its ability to disrupt membranes. DNA damage is the major contributor to the activity of the ATCUN-sh-buforin peptides. Our findings indicate that the addition of ATCUN motifs to AMPs is a simple strategy that leads to AMPs with higher antibacterial activity and possibly to more potent, usable antibacterial agents.

  16. Appropriate Fe (II) Addition Significantly Enhances Anaerobic Ammonium Oxidation (Anammox) Activity through Improving the Bacterial Growth Rate

    PubMed Central

    Liu, Yiwen; Ni, Bing-Jie

    2015-01-01

    The application of anaerobic ammonium oxidation (Anammox) process is often limited by the slow growth rate of Anammox bacteria. As the essential substrate element that required for culturing Anammox sludge, Fe (II) is expected to affect Anammox bacterial growth. This work systematically studied the effects of Fe (II) addition on Anammox activity based on the kinetic analysis of specific growth rate using data from batch tests with an enriched Anammox sludge at different dosing levels. Results clearly demonstrated that appropriate Fe (II) dosing (i.e., 0.09 mM) significantly enhanced the specific Anammox growth rate up to 0.172 d−1 compared to 0.118 d−1 at regular Fe (II) level (0.03 mM). The relationship between Fe (II) concentration and specific Anammox growth rate was found to be well described by typical substrate inhibition kinetics, which was integrated into currently well-established Anammox model to describe the enhanced Anammox growth with Fe (II) addition. The validity of the integrated Anammox model was verified using long-term experimental data from three independent Anammox reactors with different Fe (II) dosing levels. This Fe (II)-based approach could be potentially implemented to enhance the process rate for possible mainstream application of Anammox technology, in order for an energy autarchic wastewater treatment. PMID:25644239

  17. Efficiency improvement using bis(trifluoromethane) sulfonamide lithium salt as a chemical additive in porphyrin based organic solar cells.

    PubMed

    Arrechea, Susana; Aljarilla, Ana; de la Cruz, Pilar; Palomares, Emilio; Sharma, Ganesh D; Langa, Fernando

    2016-10-20

    Two new conjugated acceptor-π-donor-π-acceptor (A-π-D-π-A) porphyrins have been synthesised using 3-ethylrhodanine (1a) or dicyanovinylene (1b) groups as acceptor units. Their optical and electrochemical properties made these materials excellent electron donors along with PC71BM as the acceptor for solution-processed bulk heterojunction organic solar cells. The devices based on 1a:PC71BM (1 : 2) and 1b:PC71BM (1 : 2) processed with CB showed low power conversion efficiencies (PCE) of 2.30% and 2.80%, respectively. Nonetheless, after processing the active layer using a mixture of 3 vol% of a pyridine additive in THF, the PCE was enhanced up to 5.14% and 6.06% for 1a:PC71BM and 1b:PC71BM, respectively. Moreover, when we used LiTFSI as the chemical additive in pyridine/CB-processed 1b:PC71BM an excellent PCE of 7.63% was recorded. The effects over the film morphology and the device characteristics (Jsc, Voc and FF) due to the introduction of LiTFSI are discussed.

  18. Assessment of and Improvements to Acoustic Velocimetry in Flows in Core-like Geometries

    NASA Astrophysics Data System (ADS)

    Mautino, A. R.; Adams, M. M.; Stone, D.; Triana, S. A.; Lathrop, D. P.; Lekic, V.

    2015-12-01

    Rapidly rotating fluid flows are found in a wide variety of geophysical and astrophysical contexts, including the Earth's outer core. The dynamics of such flows can be studied experimentally at conditions inaccessible to computational modeling. However, accurately measuring the mean and time-varying flows noninvasively presents a technical challenge, particularly in opaque liquids. In this study, we tackle the problem of mapping zonal flow profiles in spherical Couette flows, shear flows in a core-like geometry. These rotating flows induce shifts and splittings in the spectrum of the acoustically resonant fluid-filled cavity. The azimuthal component of flow can be estimated from the spectra of the acoustic modes, using inversion procedures adapted from Helioseismology. Here, we present a technique for reconstructing the mean velocity field using modal analysis by way of the Finite Element Method, which is used to compute the forward model accurately, taking into account structural geometries associated with the experimental setups, such as shafts and axles. Accurate forward modeling is crucial for reliable mode identification, and we demonstrate that it allows us to identify many more modes than is possible when using the spherically symmetric approximation. We model flow geometry as a superposition of low order basis flow patterns, each of which affects mode frequency splittings and shifts through advection and Coriolis forces.

  19. Improving the accuracy of convexity splitting methods for gradient flow equations

    NASA Astrophysics Data System (ADS)

    Glasner, Karl; Orizaga, Saulo

    2016-06-01

    This paper introduces numerical time discretization methods which significantly improve the accuracy of the convexity-splitting approach of Eyre (1998) [7], while retaining the same numerical cost and stability properties. A first order method is constructed by iteration of a semi-implicit method based upon decomposing the energy into convex and concave parts. A second order method is also presented based on backwards differentiation formulas. Several extrapolation procedures for iteration initialization are proposed. We show that, under broad circumstances, these methods have an energy decreasing property, leading to good numerical stability. The new schemes are tested using two evolution equations commonly used in materials science: the Cahn-Hilliard equation and the phase field crystal equation. We find that our methods can increase accuracy by many orders of magnitude in comparison to the original convexity-splitting algorithm. In addition, the optimal methods require little or no iteration, making their computation cost similar to the original algorithm.

  20. Improvement of Frozen Storage Tolerance by the Addition of Sugar in Dusky Spinefoot, Lizard fish and Horse mackerel Surimi

    NASA Astrophysics Data System (ADS)

    Kawashima, Akane; Hamada, Yuki; Kusano, Sawa; Osako, Kazufumi; Tachibana, Katsuyasu; Nozaki, Yukinori

    The effects of three different sugars (sucrose, trehalose, sorbitol, at 5%) were analyzed and compared against a control for frozen surimi (-25 °C) made from dusky spinefoot, lizard fish and horse mackerel, for a total storage period of 180 days. Kamaboko was prepared at defined time intervals, and its jelly strength (J.S.), water holding capacity (W.H.C.), and whiteness, and the total Ca-ATPase activity of surimi were analyzed. Present results showed that all parameters of sugar free control samples decreased faster than those of sugar added samples during frozen storage.Sugar resulted a good additive for long time surimi conservation for all the species analyzed.

  1. The Evaluation of Triphenyl Phosphate as a Flame Retardant Additive to Improve the Safety of Lithium-Ion Battery Electrolytes

    NASA Technical Reports Server (NTRS)

    Smart, M. C.; Krause, F. C.; Hwang, C.; Westa, W. C.; Soler, J.; Prakash, G. K. S.; Ratnakumar, B. V.

    2011-01-01

    NASA is actively pursuing the development of advanced electrochemical energy storage and conversion devices for future lunar and Mars missions. The Exploration Technology Development Program, Energy Storage Project is sponsoring the development of advanced Li-ion batteries and PEM fuel cell and regenerative fuel cell systems for the Altair Lunar Lander, Extravehicular Activities (EVA), and rovers and as the primary energy storage system for Lunar Surface Systems. At JPL, in collaboration with NASA-GRC, NASA-JSC and industry, we are actively developing advanced Li-ion batteries with improved specific energy, energy density and safety. One effort is focused upon developing Li-ion battery electrolyte with enhanced safety characteristics (i.e., low flammability). A number of commercial applications also require Li-ion batteries with enhanced safety, especially for automotive applications.

  2. Improve Quality of Life - additional criteria for health and social care information technology acceptance in an ageing world.

    PubMed

    Monteiro, Jorge

    2012-01-01

    Reversing the rising cost of health and social systems is needed in ageing developed and developing countries. A new model of ageing is advocated by the World Health Organization. This new model asks for more personal health accountability and a more integrated approach on care and preventive cure. Information systems and technologies can play an important role in supporting the changes needed in order to have better and more sustainable health and social care systems. Using value and results for patients as criteria by which systems are accepted by users and by organizations can contribute to a value based competition in health and social care systems. The unified theory of acceptance and use of technology is presented, and the pertinence of adding an extension to the theory in order capture Quality of Life improvements expectations is explored.

  3. Addition of gut active carbohydrates to colostrum replacer does not improve passive transfer of immunoglobulin G in Holstein dairy calves.

    PubMed

    Villettaz Robichaud, M; Godden, S M; Haines, D M; Haley, D B; Pearl, D L

    2014-09-01

    The primary objective of this study was to investigate the effects of supplementing a commercial colostrum replacer (CR) with gut active carbohydrates (GAC) on passive transfer of IgG in commercial dairy calves. A secondary objective was to evaluate the effect of treatment on preweaning health and growth. A total of 240 newborn Holstein dairy calves on a commercial dairy farm were enrolled in this study. Newborn heifer and bull calves were weighed and then randomly assigned to either the treated group [GAC: 30g of GAC mixed into 1.5 doses (150g of IgG) of commercial colostrum replacer; n=119] or the control group [CON: 1.5 doses (150g of IgG) of CR; n=121]. The assigned CR treatment was fed within 3.5h of birth using an esophageal tube feeder. Venous blood samples were collected at 0 and 24h of age and used to measure serum IgG (mg/mL) and serum total protein (g/dL) concentrations and to estimate the apparent efficiency of absorption of IgG (%). The 129 heifers calves enrolled (CON=60; GAC=69) were also followed until weaning to assess the effect of GAC addition on preweaning health and growth. Multivariable linear regression showed that the addition of GAC to CR did not influence passive transfer of IgG, as measured by apparent efficiency of absorption at 24h of age (CON=54.0 vs. GAC=54.3%), serum IgG (CON=20.3 vs. GAC=20.2mg/mL), and serum total protein (CON=5.69 vs. GAC=5.68g/dL). Although study sample sizes were not originally derived to evaluate health outcomes, treatment had no effect on weight gain or incidence of health events (diarrhea, pneumonia, mortality) for heifer calves between birth and 7 wk of age.

  4. Addition of n-butyl cyanoacrylate to classic transarterial chemoembolization may improve the radiological response in patients with hepatocellular carcinoma

    PubMed Central

    Monsignore, Lucas Moretti; Elias-Junior, Jorge; Muglia, Valdair Francisco; Teixeira, Andreza Correa; Mente, Enio David; de Lourdes Candolo Martinelli, Ana; Abud, Daniel Giansante

    2015-01-01

    OBJECTIVE: Transarterial chemoembolization is the treatment of choice for intermediate-stage hepatocellular carcinoma. However, there are no clear data supporting transarterial chemoembolization vs. transarterial embolization or regarding the best chemotherapeutic agent, which may suggest a preponderant role of ischemia over chemotherapeutic action. This study sought to evaluate the radiological response and outcome of transarterial chemoembolization modified by n-butyl cyanoacrylate addition compared to conventional transarterial chemoembolization in hepatocellular carcinoma patients. MATERIALS AND METHODS: A retrospective review identified forty-seven patients who underwent modified chemoembolization and thirty-three who underwent conventional chemoembolization between June 2006 and December 2011. The radiological response was reassessed using the modified Response Evaluation Criteria in Solid Tumors. The sustained complete response, time to progression and overall survival rates were also analyzed. RESULTS: Complete response rates were significantly higher in patients who had undergone modified chemoembolization compared to those who had undergone conventional treatment (61.7% and 24.3%, respectively; p<0.001). The rate of sustained complete response was significantly higher in the modified chemoembolization group compared to the conventional chemoembolization group (median of 236 and 37 days, respectively; p<0.001). Time to progression was significantly higher in the modified chemoembolization group compared to the conventional chemoembolization group (median of 424 and 201 days, respectively; p=0.042). Overall survival rates revealed no difference between patients who received modified chemoembolization and conventional chemoembolization (median of 483 and 399 days, respectively; p=0.316). CONCLUSION: Transarterial chemoembolization modified by n-butyl cyanoacrylate addition was superior to conventional transarterial chemoembolization in terms of the

  5. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  6. Proposed Ice Flow, Given 200m and 400m Additional Ice in the Allan Hills Region, Antarctica: Implications for Meteorite Concentration

    NASA Astrophysics Data System (ADS)

    Traub-Metlay, S.; Cassidy, W. A.

    1992-07-01

    The Allan Hills-David Glacier region contains some of the most highly populated meteorite stranding surfaces in Antarctica. Nearly 2000 meteorites have to date been collected from the icefields associated with the Allan Hills, and nearly 1500 from areas around Elephant Moraine. While much attention has been focused on the current geological and glaciological conditions of these stranding surfaces, less work has been done concerning what they may have looked like in the past, when ice thicknesses may have been greater. In this study, conjectural maps of the current Allan Hills area with 200 meters and 400 meters of additional ice cover each are analyzed for probable regional and local ice flow patterns. A dramatic decrease in ice thickness over a relatively brief period of time could result either from climatic change or a geologically rapid regional uplift. Delisle and Sievers (1991) noted that the valley between the Allan Hills Main Icefield and the Allan Hills resembles a half-graben resulting from east-west extensional tectonics, and that the mesa-like bedrock features associated with the Near Western and Mid Western Icefields resemble fault blocks. They concluded that the Allan Hills area icefields may have become active stranding surfaces as a result of a regional uplift within the past 1-2 million years, assuming a current rate of uplift in the Allan Hills region of ~100 meters/million years. Whether the cause was climatic or tectonic, generalized maps of current ice contours plus 400 and 200 meters ice may provide views of what the Allan Hills region looked like just before activation of the modern meteorite stranding surfaces (Figs. 1 and 2). At an ice thickness greater by 400 meters, ice could flow smoothly over the Allan Hills and would drain down to the Mawson Glacier via the Odell Glacier, east of the Allan Hills; down the Manhaul Bay depression between the east and west arms of Allan Hills; and down the half-graben discovered by Delisle and Sievers

  7. Design optimization of axial flow hydraulic turbine runner: Part I - an improved Q3D inverse method

    NASA Astrophysics Data System (ADS)

    Peng, Guoyi; Cao, Shuliang; Ishizuka, Masaru; Hayama, Shinji

    2002-06-01

    With the aim of constructing a comprehensive design optimization procedure of axial flow hydraulic turbine, an improved quasi-three-dimensional inverse method has been proposed from the viewpoint of system and a set of rotational flow governing equations as well as a blade geometry design equation has been derived. The computation domain is firstly taken from the inlet of guide vane to the far outlet of runner blade in the inverse method and flows in different regions are solved simultaneously. So the influence of wicket gate parameters on the runner blade design can be considered and the difficulty to define the flow condition at the runner blade inlet is surmounted. As a pre-computation of initial blade design on S2m surface is newly adopted, the iteration of S1 and S2m surfaces has been reduced greatly and the convergence of inverse computation has been improved. The present model has been applied to the inverse computation of a Kaplan turbine runner. Experimental results and the direct flow analysis have proved the validation of inverse computation. Numerical investigations show that a proper enlargement of guide vane distribution diameter is advantageous to improve the performance of axial hydraulic turbine runner. Copyright

  8. Flow analysis techniques as effective tools for the improved environmental analysis of organic compounds expressed as total indices.

    PubMed

    Maya, Fernando; Estela, José Manuel; Cerdà, Víctor

    2010-04-15

    The scope of this work is the accomplishment of an overview about the current state-of-the-art flow analysis techniques applied to the environmental determination of organic compounds expressed as total indices. Flow analysis techniques are proposed as effective tools for the quick obtention of preliminary chemical information about the occurrence of organic compounds on the environment prior to the use of more complex, time-consuming and expensive instrumental techniques. Recently improved flow-based methodologies for the determination of chemical oxygen demand, halogenated organic compounds and phenols are presented and discussed in detail. The aim of the present work is to demonstrate the highlight of flow-based techniques as vanguard tools on the determination of organic compounds in environmental water samples.

  9. From the track to the ocean: Using flow control to improve marine bio-logging tags for cetaceans

    PubMed Central

    Fiore, Giovani; Anderson, Erik; Garborg, C. Spencer; Murray, Mark; Johnson, Mark; Moore, Michael J.; Howle, Laurens

    2017-01-01

    Bio-logging tags are an important tool for the study of cetaceans, but superficial tags inevitably increase hydrodynamic loading. Substantial forces can be generated by tags on fast-swimming animals, potentially affecting behavior and energetics or promoting early tag removal. Streamlined forms have been used to reduce loading, but these designs can accelerate flow over the top of the tag. This non-axisymmetric flow results in large lift forces (normal to the animal) that become the dominant force component at high speeds. In order to reduce lift and minimize total hydrodynamic loading this work presents a new tag design (Model A) that incorporates a hydrodynamic body, a channel to reduce fluid speed differences above and below the housing and wing to redirect flow to counter lift. Additionally, three derivatives of the Model A design were used to examine the contribution of individual flow control features to overall performance. Hydrodynamic loadings of four models were compared using computational fluid dynamics (CFD). The Model A design eliminated all lift force and generated up to ~30 N of downward force in simulated 6 m/s aligned flow. The simulations were validated using particle image velocimetry (PIV) to experimentally characterize the flow around the tag design. The results of these experiments confirm the trends predicted by the simulations and demonstrate the potential benefit of flow control elements for the reduction of tag induced forces on the animal. PMID:28196148

  10. From the track to the ocean: Using flow control to improve marine bio-logging tags for cetaceans.

    PubMed

    Fiore, Giovani; Anderson, Erik; Garborg, C Spencer; Murray, Mark; Johnson, Mark; Moore, Michael J; Howle, Laurens; Shorter, K Alex

    2017-01-01

    Bio-logging tags are an important tool for the study of cetaceans, but superficial tags inevitably increase hydrodynamic loading. Substantial forces can be generated by tags on fast-swimming animals, potentially affecting behavior and energetics or promoting early tag removal. Streamlined forms have been used to reduce loading, but these designs can accelerate flow over the top of the tag. This non-axisymmetric flow results in large lift forces (normal to the animal) that become the dominant force component at high speeds. In order to reduce lift and minimize total hydrodynamic loading this work presents a new tag design (Model A) that incorporates a hydrodynamic body, a channel to reduce fluid speed differences above and below the housing and wing to redirect flow to counter lift. Additionally, three derivatives of the Model A design were used to examine the contribution of individual flow control features to overall performance. Hydrodynamic loadings of four models were compared using computational fluid dynamics (CFD). The Model A design eliminated all lift force and generated up to ~30 N of downward force in simulated 6 m/s aligned flow. The simulations were validated using particle image velocimetry (PIV) to experimentally characterize the flow around the tag design. The results of these experiments confirm the trends predicted by the simulations and demonstrate the potential benefit of flow control elements for the reduction of tag induced forces on the animal.

  11. Bubble Size Control to Improve Oxygen-Based Bleaching: Characterization of Flow Regimes in Pulp-Water-Gas Three-Phase Flows

    SciTech Connect

    S.M. Ghiaasiaan and Seppo Karrila

    2006-03-20

    Flow characteristics of fibrous paper pulp-water-air slurries were investigated in a vertical circular column 1.8 m long, with 5.08 cm diameter. Flow structures, gas holdup (void fraction), and the geometric and population characteristics of gas bubbles were experimentally investigated, using visual observation, Gamma-ray densitometry, and flash X-ray photography. Five distinct flow regimes could be visually identified: dispersed bubbly, layered bubbly, plug, churn-turbulent, and slug. Flow regime maps were constructed, and the regime transition lines were found to be sensitive to consistency. The feasibility of using artificial neural networks (ANNs) for the identification of the flow regimes, using the statistical characteristics of pressure fluctuations measured by a single pressure sensor, was demonstrated. Local pressure fluctuations at a station were recorded with a minimally-intrusive transducer. Three-layer, feed-forward ANNs were designed that could identify the four major flow patterns (bubbly, plug, churn, and slug) well. The feasibility of a transportable artificial neural network (ANN) - based technique for the classification of flow regimes was also examined. Local pressures were recorded at three different locations using three independent but similar transducers. An ANN was designed, trained and successfully tested for the classification of the flow regimes using one of the normalized pressure signals (from Sensor 1). The ANN trained and tested for Sensor 1 predicted the flow regimes reasonably well when applied directly to the other two sensors, indicating a good deal of transportability. An ANN-based method was also developed, whereby the power spectrum density characteristics of other sensors were adjusted before they were used as input to the ANN that was based on Sensor 1 alone. The method improved the predictions. The gas-liquid interfacial surface area concentration was also measured in the study. The gas absorption technique was applied

  12. Perspectives on the utilization of aquaculture coproduct in Europe and Asia: prospects for value addition and improved resource efficiency.

    PubMed

    Newton, Richard; Telfer, Trevor; Little, Dave

    2014-01-01

    Aquaculture has often been criticized for its environmental impacts, especially efficiencies concerning global fisheries resources for use in aquafeeds among others. However, little attention has been paid to the contribution of coproducts from aquaculture, which can vary between 40% and 70% of the production. These have often been underutilized and could be redirected to maximize the efficient use of resource inputs including reducing the burden on fisheries resources. In this review, we identify strategies to enhance the overall value of the harvested yield including noneffluent processing coproducts for three of the most important global aquaculture species, and discuss the current and prospective utilization of these resources for value addition and environmental impact reduction. The review concludes that in Europe coproducts are often underutilized because of logistical reasons such as the disconnected nature of the value chain, and perceived legislative barriers. However, in Asia, most coproducts are used, often innovatively but not to their full economic potential and sometimes with possible human health and biosecurity risks. These include possible spread of diseased material and low traceability in some circumstances. Full economic and environmental appraisal is long overdue for the current and potential strategies available for coproduct utilization.

  13. Improving iron-enriched basalt with additions of ZrO{sub 2} and TiO{sub 2}

    SciTech Connect

    Reimann, G.A.; Kong, P.C.

    1993-06-01

    The iron-enriched basalt (IEB) waste form, developed at the Idaho National Engineering Laboratory a decade ago, was modified to IEB4 by adding sufficient ZrO{sub 2} and TiO{sub 2} to develop crystals of zirconolite upon cooling, in addition to the crystals that normally form in a cooling basalt. Zirconolite (CaZrTi{sub 2}O{sub 7}) is an extremely leach-resistant mineral with a strong affinity for actinides. Zirconolite crystals containing uranium and thorium have been found that have endured more than 2 billion years of natural processes. On this basis, zirconolite was considered to be an ideal host crystal for the actinides contained in transuranic (TRU)-contaminated wastes. Crystals of zirconolite were developed in laboratory melts of IEB4 that contained 5% each of ZrO{sub 2} and TiO{sub 2} and that were slow-cooled in the 1200--1000{degrees}C range. When actinide surrogates were added to IEB4, these oxides were incorporated into the crystals of zirconolite rather than precipitating in the residual glass phase. Zirconolite crystals developed in IEB4 should stabilize and immobilize the dilute TRUs in heterogeneous, buried low-level wastes as effectively as this same phase does in the various formulations of Synroc used for the more concentrated TRUs encountered in high-level wastes. Synroc requires hot-pressing equipment, while IEB4 precipitates zirconolite from a cooling basaltic melt.

  14. Effects of Sucrose Stearate Addition on the Quality Improvement of Ready-To-Eat Samgyetang During Storage at 25℃

    PubMed Central

    2014-01-01

    The effects of sucrose stearate at various concentrations (0.1%, 0.2%, and 0.3%, w/v) on the physico-chemical characteristics of ready-to-eat (RTE) Samgyetang were investigated during storage at 25℃ for 12 mon. Over the storage duration, the addition of sucrose stearate had no significant effects on the proximate composition of Samgyetang, including meat, broth, and porridge, or the hardness and spreadability of the porridge, although it resulted in significantly higher CIE L* values for the porridge. The CIE L* values of Samgyetang porridge with added sucrose stearate increased until 9 mon, while the control decreased until 6 mon, and the values for both changed insignificantly thereafter. The breast meat of Samgyetang treated with sucrose stearate showed higher percentages of polyunsaturated fatty acid after 3 mon and lower percentages of monounsaturated fatty acid after 6 mon compared to the control (p<0.05), while no significant differences were observed with the different sucrose stearate concentrations (p>0.05). The overall sensory acceptability scores were higher at sucrose stearate concentrations of 0.2% or 0.3% after 6 mon and at 0.1% after 9 mon compared to those of the control. PMID:26761503

  15. Addition of a video camera system improves the ease of Airtraq(®) tracheal intubation during chest compression.

    PubMed

    Kohama, Hanako; Komasawa, Nobuyasu; Ueki, Ryusuke; Itani, Motoi; Nishi, Shin-ichi; Kaminoh, Yoshiroh

    2012-04-01

    Recent resuscitation guidelines for cardiopulmonary resuscitation emphasize that rescuers should perform tracheal intubation with minimal interruption of chest compressions. We evaluated the use of video guidance to facilitate tracheal intubation with the Airtraq (ATQ) laryngoscope during chest compression. Eighteen novice physicians in our anesthesia department performed tracheal intubation on a manikin using the ATQ with a video camera system (ATQ-V) or with no video guidance (ATQ-N) during chest compression. All participants were able to intubate the manikin using the ATQ-N without chest compression, but five failed during chest compression (P < 0.05). In contrast, all participants successfully secured the airway with the ATQ-V, with or without chest compression. Concurrent chest compression increased the time required for intubation with the ATQ-N (without chest compression 14.8 ± 4.5 s; with chest compression, 28.2 ± 10.6 s; P < 0.05), but not with the ATQ-V (without chest compression, 15.9 ± 5.8 s; with chest compression, 17.3 ± 5.3 s; P > 0.05). The ATQ video camera system improves the ease of tracheal intubation during chest compressions.

  16. Potent Vinblastine C20′ Ureas Displaying Additionally Improved Activity Against a Vinblastine-Resistant Cancer Cell Line

    PubMed Central

    2013-01-01

    A series of disubstituted C20′-urea derivatives of vinblastine were prepared from 20′-aminovinblastine that was made accessible through a unique Fe(III)/NaBH4-mediated alkene functionalization reaction of anhydrovinblastine. Three analogues were examined across a panel of 15 human tumor cell lines, displaying remarkably potent cell growth inhibition activity (avg. IC50 = 200–300 pM), being 10–200-fold more potent than vinblastine (avg. IC50 = 6.1 nM). Significantly, the analogues also display further improved activity against the vinblastine-resistant HCT116/VM46 cell line that bears the clinically relevant overexpression of Pgp, exhibiting IC50 values on par with that of vinblastine against the sensitive HCT116 cell line, 100–200-fold greater than the activity of vinblastine against the resistant HCT116/VM46 cell line, and display a reduced 10–20-fold activity differential between the matched sensitive and resistant cell lines (vs 100-fold for vinblastine). PMID:24223237

  17. Improvement of microstructure and magnetic properties of Nd-Fe-B alloys by Nb and Co additions

    NASA Astrophysics Data System (ADS)

    Ahmed, F. M.; Harris, I. R.

    In order to establish the role of niobium on the hydrogenation, disproportionation, desorption and recombination (HDDR) behavior of near-stoichiometric alloys, two alloys: NdI3Fe8OB7 and Nd13Fe78Nb1Co1B7 (at%) were investigated before, during and after the HDDR process. The microstructure of the as-cast Nb-free alloy before employing the HDDR process was found to consist of three phases, the matrix Nd 2Fe 14B (φ) phase, Nd-rich phase and a significant amount of free iron; whereas, the microstructure of the Nb-containing alloy consisted of only the first two phases. The HDDR behavior of the above alloys was characterized using a high-resolution scanning electron microscope (HRSEM). The disproportionation of the Nd 2Fe 14B (φ) matrix phase starts at the Nd-rich/φ phase interface, resulting in the formation of a sub-micron structure consisting of Fe, Fe 2B and Nd-hydride. The disproportionated structures of the Nb-free alloy contained large arms of free iron dendrites, which were retained from the as-cast structures. In the niobium-containing alloy, the recombined grains appear finer and with more rounded shapes in comparison with those of the NdFeB alloy. Promising magnetic properties have been obtained for bonded magnets using the HDDR powder. The magnetic properties, especially the intrinsic coercivity, improved significantly by using ˜1% Nd in excess of the stoichiometric content.

  18. Addition of HfO2 interface layer for improved synaptic performance of phase change memory (PCM) devices

    NASA Astrophysics Data System (ADS)

    Suri, M.; Bichler, O.; Hubert, Q.; Perniola, L.; Sousa, V.; Jahan, C.; Vuillaume, D.; Gamrat, C.; DeSalvo, B.

    2013-01-01

    In this work, we will focus on the use of phase change memory (PCM) to emulate synaptic behavior in emerging neuromorphic system-architectures. In particular, we will show that the performance and energy-efficiency of large scale neuromorphic systems can be improved by engineering individual PCM devices used as synapses. This is obtained by adding a thin HfO2 interface layer to standard GST PCM devices, allowing for the lowering of the Set/Reset currents and the increase of the number of intermediate resistance states (or synaptic weights) in the synaptic potentiation characteristics. The experimentally obtained potentiation characteristics of such PCM devices are used to simulate a 2-layer ultra-dense spiking neural network (SNN) and to perform a complex visual pattern extraction from a test case based on real world data (i.e. cars passing on a 6-lane freeway). The total power dissipated in the learning mode, for the pattern extraction experiment is estimated to be as low as 60 μW. Average detection rate of cars is found to be greater than 90%.

  19. Pretreatment of Asian elephant (Elephas maximus) spermatozoa with cholesterol-loaded cyclodextrins and glycerol addition at 4°C improves cryosurvival.

    PubMed

    Kiso, Wendy K; Asano, Atsushi; Travis, Alexander J; Schmitt, Dennis L; Brown, Janine L; Pukazhenthi, Budhan S

    2012-01-01

    Asian elephant spermatozoa are sensitive to chilling and do not respond well to cryopreservation. The objectives of the present study were to: (1) determine whether cholesterol content can be modified by preincubation of Asian elephant spermatozoa with cholesterol-loaded cyclodextrin (CLC); and (2) assess the effects of CLC concentration(s), temperature at time of glycerol addition (22°C vs 4°C) and dilution medium on post-thaw sperm survival. Spermatozoa incubated with ≥1.5 mg CLC exhibited increased (P < 0.05) cholesterol concentrations. Pretreatment of spermatozoa with 1.5 mg CLC resulted in improvements (P < 0.05) in all post-thaw parameters. Glycerol addition at 4°C also improved all post-thaw parameters compared with 22°C. Dilution of thawed spermatozoa in an egg yolk-based medium improved (P < 0.05) motility compared with Ham's F-10 culture medium. In summary, our findings indicate that modifying cholesterol content within the plasma membrane improves the cryosurvival of Asian elephant spermatozoa. The development of an improved cryopreservation method that includes modification of membrane cholesterol and the addition of glycerol at 4°C, as reported in the present study, is an important step towards utilisation of cryopres