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Sample records for layer inline separator

  1. Low Cost Geothermal Separators BLISS Boundary Layer Inline Separator Scrubber

    SciTech Connect

    Jung, Douglas; Wai, King

    2000-05-26

    A new compact, low cost, and high performance separator is being developed to help reduce the installed and O and M cost of geothermal power generation. This device has been given the acronym ''BLISS'' that stands for ''Boundary Layer Inline Separator Scrubber''. The device is the first of a series of separators, and in the case of injectates, scrubbers to address the cost-reduction needs of the industry. The BLISS is a multi-positional centrifugal separator primarily designed to be simply installed between pipe supports, in a horizontal position. This lower profile reduces the height safety concern for workers, and significantly reduces the total installation cost. The vessel can demand as little as one-quarter (25%) the amount of steel traditionally required to fabricate many large vertical separators. The compact nature and high separating efficiency of this device are directly attributable to a high centrifugal force coupled with boundary layer control. The pseudo isokinetic flow design imparts a self-cleaning and scale resistant feature. This polishing separator is designed to remove moderate amounts of liquid and entrained solids.

  2. Interaction of in-line twin synthetic jets with a separated flow

    NASA Astrophysics Data System (ADS)

    Wen, Xin; Tang, Hui; Duan, Fei

    2016-04-01

    An experimental investigation is carried out in a water tunnel to investigate the interaction of in-line twin synthetic jets (SJs) with a separated laminar boundary layer over inclined plates. The flow structures induced by the in-line twin SJs at four phase differences and their resulting flow separation delay are examined using dye visualization and particle image velocimetry (PIV) measurements. It is found that, in most of the cases, the heads of hairpin vortices that are produced from the upstream SJ actuator do not change too much, and the vortex legs are highly stretched by the separated shear layer. An exception is the case with 90° phase difference where the combined vortex head appears as a reversed letter "S" and the combined vortex legs are high enough to escape from the influence of the separated flow. Compared to the single SJ, the twin SJs generally exert greater influence on the separated flow regardless of the phase difference. The PIV results in the mid-span plane reveal that the periodic passage of vortex structures influences the separated flow significantly, causing the flapping of the upper edge of the reversed flow region that contributes to the flow separation delay. The delay of separation is also demonstrated by a streak of forward flow protrusion in the wall-parallel PIV results. It is found that the streak varies a lot at different phase differences. Proper orthogonal decomposition analysis is also conducted and two major types of energetic flow structures in the SJ controlled flow are identified: a strip of back-and-forth fluctuation along the upper edge of the reversed flow, and the vortex structures produced by the twin SJs. It is found that the fluctuation strip is most energetic in the single SJ case and the case with 270° phase difference, whereas the convective mode pair is most energetic in the case with 90° phase difference.

  3. Vortex dynamics of in-line twin synthetic jets in a laminar boundary layer

    NASA Astrophysics Data System (ADS)

    Wen, Xin; Tang, Hui; Duan, Fei

    2015-08-01

    An experimental investigation is conducted on the vortices induced by twin synthetic jets (SJs) in line with a laminar boundary layer flow over a flat plate. The twin SJs operating at four different phase differences, i.e., Δϕ = 0°, 90°, 180°, and 270°, are visualized using a stereoscopic color dye visualization system and measured using a two-dimensional particle image velocimetry (PIV) system. It is found that depending on the phase difference of twin SJs, three types of vortex structures are produced. At Δϕ = 90°, the two hairpin vortices interact in a very constructive way in terms of the vortex size, strength, and celerity, forming one combined vortex. At Δϕ = 270°, the two individual hairpin vortices do not have much interaction, forming two completely separated hairpin vortices that behave like doubling the frequency of the single SJ case. At Δϕ = 0° and 180°, the two hairpin vortices produced by the twin SJ actuators are close enough, with the head of one hairpin vortex coupled with the legs of the other, forming partially interacting vortex structures. Quantitative analysis of the twin SJs is conducted, including the time histories of vortex circulation in the mid-span plane as well as a selected spanwise-wall-normal plane, and the influence of the twin SJs on the boundary layer flow filed. In addition, dynamic mode decomposition analysis of the PIV data is conducted to extract representative coherent structures. Through this study, a better understanding in the vortex dynamics associated with the interaction of in-line twin SJs in laminar boundary layers is achieved, which provides useful information for future SJ-array applications.

  4. In-line filtration of platelet concentrates obtained with the Omnix blood cell separator.

    PubMed

    Moog, R; Müller, N; Nieper, A

    1995-12-01

    The quality of platelet concentrates (PC) obtained with the blood cell separator Omnix was investigated before and after in-line filtration. PC were filtered 2h (protocol A) and 4 h (protocol B) after the termination of apheresis. Platelet (PLT) yield after filtration was similar in both protocols (median 3.7 vs. 3.4 x 10(11)). Median white blood cell (WBC) contamination after leucocyte depletion was 0.07 x 10(6) (range 0.02-3.27 x 10(6)) in protocol A and 0.06 x 10(6) (range 0.02-2.1 x 10(6)) in protocol B. Glucose, lactate, lactate dehydrogenase, morphology score and pH value were not statistically different before and after filtration in both protocols. We conclude that in-line filtration results in sufficient leucocyte depletion of the PC. The prefiltration storage time did not influence the studied parameters of product quality. PMID:8646295

  5. Boundary Layers, Transitions and Separation

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Effects of roughness in boundary layers have to be addressed. Until adverse pressure gradient effects are understood, roughness will not significantly drive design. Mechanisms responsible for separation not understood. Effects on Zero Pressure Gradient boundary layers (shear stress). Effects on separation in pressure gradient (prediction of separation). Effect on scalar transport (heat transfer) not understood. Model for skin friction needed in simulations - first grid point likely to be in buffer layer. Definition of roughness important for useful experiments. A lot of validation experiments will be needed. How to get to ks for roughness of engineering interest? - depends on wavelength height, etc. for engineering interest? Re-discovering the wheel should be avoided: existing knowledge (theoretical and experimental) should find its way into the engineering models. It is a task of the industry to filter out the existing information in the literature for results relevant to its application, being external or internal.

  6. Cyclone separator having boundary layer turbulence control

    DOEpatents

    Krishna, Coimbatore R.; Milau, Julius S.

    1985-01-01

    A cyclone separator including boundary layer turbulence control that is operable to prevent undue build-up of particulate material at selected critical areas on the separator walls, by selectively varying the fluid pressure at those areas to maintain the momentum of the vortex, thereby preventing particulate material from inducing turbulence in the boundary layer of the vortical fluid flow through the separator.

  7. Three-dimensional boundary layers approaching separation

    NASA Technical Reports Server (NTRS)

    Williams, J. C., III

    1976-01-01

    The theory of semi-similar solutions of the laminar boundary layer equations is applied to several flows in which the boundary layer approaches a three-dimensional separation line. The solutions obtained are used to deduce the nature of three-dimensional separation. It is shown that in these cases separation is of the "ordinary" type. A solution is also presented for a case in which a vortex is embedded within the three-dimensional boundary layer.

  8. Dense, layered membranes for hydrogen separation

    DOEpatents

    Roark, Shane E.; MacKay, Richard; Mundschau, Michael V.

    2006-02-21

    This invention provides hydrogen-permeable membranes for separation of hydrogen from hydrogen-containing gases. The membranes are multi-layer having a central hydrogen-permeable layer with one or more catalyst layers, barrier layers, and/or protective layers. The invention also relates to membrane reactors employing the hydrogen-permeable membranes of the invention and to methods for separation of hydrogen from a hydrogen-containing gas using the membranes and reactors. The reactors of this invention can be combined with additional reactor systems for direct use of the separated hydrogen.

  9. Real and virtual image separation in digital in-line holography microscopy by recording two parallel holograms

    NASA Astrophysics Data System (ADS)

    Ling, Hangjian; Katz, Joseph

    2013-11-01

    Maintaining high magnification and micron resolution in applications of digital in-line holography microscopy for 3D velocity measurements requires a hologram plane located very close or even within the sample volume. Separation between overlapping real and virtual images becomes a challenge in such cases. Here, we introduced a simple method based on recording two holograms through the same microscope objective that are separated by a short distance from each other. When the same particle fields are reconstructed from the two holograms, the real images overlap, whereas virtual images are separated by twice the distance between hologram planes. Thus, real and virtual images can be easily distinguished. Due to the elongation of the reconstructed particle in the axial direction, the distance between hologram planes is selected to exceed the elongated traces. This technique has been applied to record 3D traces of thousands of 2 um particles in a 0 . 5 × 0 . 5 × 0 . 5 mm sample volume using hologram planes separated by 27 um. Experimental setup, alignment and data analysis procedures, including reconstruction, calibration, particles segmentation and precision particles positioning will be discussed. Sponsored by ONR.

  10. Electrostatic Separation Of Layers In Thermal Insulation

    NASA Technical Reports Server (NTRS)

    Bhandari, Pradeep

    1995-01-01

    Layers in multilayer insulation charged to keep them separated by electrostatic repulsion, eliminating need for spacer nets. Removal of spacer nets reduces conduction of heat between layers. Insulation in question type used to slow leakage of heat into Dewar flasks containing liquid helium. Proposal originally applied to insulation in cryogenic cooling subsystems of infrared-detector systems in outer space, also appears applicable to small panels of insulation for terrestrial cryogenic equipment, provided layers contained in evacuated spaces and weight of each layer small fraction of electrostatic force upon it.

  11. Near-infrared chemical imaging used for in-line analysis of inside adhesive layers in textile laminates.

    PubMed

    Mirschel, Gabriele; Daikos, Olesya; Scherzer, Tom; Steckert, Carsten

    2016-08-17

    This paper demonstrates for the first time that near-infrared (NIR) chemical imaging can be used for in-line analysis of textile lamination processes. In particular, it was applied for the quantitative determination of the applied coating weight and for monitoring of the spatial distribution of hot melt adhesive layers using chemometric approaches for spectra evaluation. Layers with coating weights between about 25 and 130 g m(-2) were used for the lamination of polyester fabrics and nonwovens as well as for polyurethane foam. It was shown that quantitative data with adequate precision can be actually obtained for layers applied to materials with significantly heterogeneous surface structure such as foam or for hidden layers inside fabric laminates. Even the coating weight and the homogeneity of adhesive layers in composites consisting of black textiles only could be quantitatively analyzed. The prediction errors (RMSEP) determined in an external validation of each calibration model were found to range from about 2 g m(-2) to 6 g m(-2) depending on the specific system under investigation. All calibration models were applied for chemical imaging in order to prove their performance for monitoring the thickness and the homogeneity of adhesive layers in the various textile systems. Moreover, they were used for the detection of irregularities and coating defects. Investigations were carried out with a large hyperspectral camera mounted above a conveyor. Therefore, this method allows large-area monitoring of the properties of laminar materials. Consequently, it is potentially suited for process and quality control during the lamination of fabrics, foams and other materials in field-scale. PMID:27286771

  12. The multi layered approach for AGM separators

    SciTech Connect

    Ferreira, A.L.

    1999-05-01

    The present absorbent glass mat separate is an offspring of the filtration medium and special paper industries. In these industries, the traditional method of manufacturing micro-glass mats, was to blend two or more types of fibers together in an aqueous acidic solution and deposit this blend onto a moving endless wire or onto a roto-former, another version of an endless wire. The sheet acquires consistency as the water is withdrawn, it is then pressed and dried against heated drums. The methods of fiber dispersion and deposition can be changed so that the different constituent fiber types of an AGM separator are processed separately in distinct and separate layers. This fiber segregation results in changes to some key characteristics of the separator and brings some very definite advantages to the VRLA battery performance. Various key characteristics of the battery are enhanced, such as its ability to deliver higher currents at the higher discharge rates. This paper sets out some basic principles for the manufacturer of wet laid microglass fiber mats. Also important AGM characteristics, such as wicking, porosity/pore size and stratification are analyzed in light of the multilayered AGM design. These characteristics are radically modified and as a consequence the VRLA battery high rate and cycling performances are equally affected.

  13. In-line micro-matrix solid-phase dispersion extraction for simultaneous separation and extraction of Sudan dyes in different spices.

    PubMed

    Rajabi, Maryam; Sabzalian, Sedigheh; Barfi, Behruz; Arghavani-Beydokhti, Somayeh; Asghari, Alireza

    2015-12-18

    A novel, simple, fast, and miniaturized method, termed in-line micro-matrix solid-phase dispersion (in-line MMSPD), coupled with high performance liquid chromatography (HPLC) was developed for the simultaneous extraction and determination of Sudan dyes (i.e. Sudan I-IV, Sudan orange G, Sudan black B, and Sudan red G) with the aid of an experimental design strategy. In this method, a matrix solid-phase dispersion (MSPD) column including a suitable mixture of polar sorbents was inserted in the mobile phase pathway, and while the interfering compounds were retained, the analytes were eluted and entered into the analytical column. In this way, the extraction, elution, and separation of the analytes were performed sequentially. Under the optimal experimental conditions (including the amount of sample, 0.0426g; amount of dispersant phase, 0.0216g of florisil, 0.0227g of silica, 0.0141g of alumina; and blending time, 112s), the limits of detection (LODs), limits of quantification, linear dynamic ranges, and recoveries were obtained to be 0.3-15.3μgkg(-1), 1-50μgkg(-1), 50-28,000μgkg(-1), and 94.5-99.1%, respectively. The results obtained showed that determination of the selected Sudan dyes in food samples using an enough sensitive and a simple analytically validated method like in-line MMSPD may offer a suitable screening method, which could be useful for food analysis and adulteration. PMID:26614171

  14. Advances in inline quantification of co-eluting proteins in chromatography: Process-data-based model calibration and application towards real-life separation issues.

    PubMed

    Brestrich, Nina; Sanden, Adrian; Kraft, Axel; McCann, Karl; Bertolini, Joseph; Hubbuch, Jürgen

    2015-07-01

    Pooling decisions in preparative liquid chromatography for protein purification are usually based on univariate UV absorption measurements that are not able to differentiate between product and co-eluting contaminants. This can result in inconsistent pool purities or yields, if there is a batch-to-batch variability of the feedstock. To overcome this analytical bottleneck, a tool for selective inline quantification of co-eluting model proteins using mid-UV absorption spectra and Partial Least Squares Regression (PLS) was presented in a previous study and applied for real-time pooling decisions. In this paper, a process-data-based method for the PLS model calibration will be introduced that allows the application of the tool towards chromatography steps of real-life processes. The process-data-based calibration method uses recorded inline mid-UV absorption spectra that are correlated with offline fraction analytics to calibrate PLS models. In order to generate average spectra from the inline data, a Visual Basic for Application macro was successfully developed. The process-data-based model calibration was established using a ternary model protein system. Afterwards, it was successfully demonstrated in two case studies that the calibration method is applicable towards real-life separation issues. The calibrated PLS models allowed a successful quantification of the co-eluting species in a cation-exchange-based aggregate and fraction removal during the purification of monoclonal antibodies and of co-eluting serum proteins in an anion-exchange-based purification of Cohn supernatant I. Consequently, the presented process-data-based PLS model calibration in combination with the tool for selective inline quantification has a great potential for the monitoring of future chromatography steps and may contribute to manage batch-to-batch variability by real-time pooling decisions. PMID:25683378

  15. Organic light emitting device having multiple separate emissive layers

    SciTech Connect

    Forrest, Stephen R.

    2012-03-27

    An organic light emitting device having multiple separate emissive layers is provided. Each emissive layer may define an exciton formation region, allowing exciton formation to occur across the entire emissive region. By aligning the energy levels of each emissive layer with the adjacent emissive layers, exciton formation in each layer may be improved. Devices incorporating multiple emissive layers with multiple exciton formation regions may exhibit improved performance, including internal quantum efficiencies of up to 100%.

  16. Application of a Reynolds stress model to separating boundary layers

    NASA Technical Reports Server (NTRS)

    Ko, Sung HO

    1993-01-01

    Separating turbulent boundary layers occur in many practical engineering applications. Nonetheless, the physics of separation/reattachment of flows is poorly understood. During the past decade, various turbulence models were proposed and their ability to successfully predict some types of flows was shown. However. prediction of separating/reattaching flows is still a formidable task for model developers. The present study is concerned with the process of separation from a smooth surface. Features of turbulent separating boundary layers that are relevant to modeling include the following: the occurrence of zero wall shear stress, which causes breakdown of the boundary layer approximation; the law of the wall not being satisfied in the mean back flow region; high turbulence levels in the separated region; a significant low-frequency motion in the separation bubble; and the turbulence structure of the separated shear layer being quite different from that of either the mixing layers or the boundary layers. These special characteristics of separating boundary layers make it difficult for simple turbulence models to correctly predict their behavior.

  17. Hypersonic flow separation in shock wave boundary layer interactions

    NASA Technical Reports Server (NTRS)

    Hamed, A.; Kumar, Ajay

    1992-01-01

    An assessment is presented for the experimental data on separated flow in shock wave turbulent boundary layer interactions at hypersonic and supersonic speeds. The data base consists mainly of two dimensional and axisymmetric interactions in compression corners or cylinder-flares, and externally generated oblique shock interactions with boundary layers over flat plates or cylindrical surfaces. The conditions leading to flow separation and the subsequent changes in the flow empirical correlations for incipient separation are reviewed. The effects of the Mach number, Reynolds number, surface cooling and the methods of detecting separation are discussed. The pertinent experimental data for the separated flow characteristics in separated turbulent boundary layer shock interaction are also presented and discussed.

  18. The evaluation of layered separators for nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Gahn, Randall F.

    1991-01-01

    The concept of using layered separators to achieve the required electrolyte retention and bubble pressure fo nickel-hydrogen cells was evaluated in a boilerplate cell test. Zircar cloth, polyethylene paper and polypropylene felt were combined with a layer of radiation-grafted polyethylene film to achieve the required properties. Three cells of each layered separator were built and tested by characterization cycling and by low earth orbit cycling for 5000 cycles at 80 percent DOD. Three cells containing asbestos separators were used as the reference.

  19. Radionuclide separations using pillared layered materials

    SciTech Connect

    Schroeder, N.C.; Wade, K.L.; Morgan, D.M.

    1998-12-31

    This is the final report of a two-year Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Pillared Layered Materials (PLMs) are layered inorganic ion exchangers propped apart by metal oxide pillars. PLMs have been synthesized to sorb strontium from liquid nuclear wastes. A study that compared over 60 sorbers for their ability to sorb strontium from Hanford simulants showed that PLMs were the best sorbers; strontium distribution coefficients ({sup Sr}K{sub d}) > 20000 mL/g were obtained. In addition, PLMs showed a high degree of selectivity for strontium over cesium, transition metals, lanthanides and actinides. The sorption of strontium is, however, inhibited by complexants (EDTA); {sup Sr}K{sub d} values drop to <20 mL/g when they are present. The most promising PLMs were the Cr, Ti, Zr, and Si pillared tantalum tungstate. The K{sub d} values for Sr{sup 2+} and Ba{sup 2+} show a strong pH dependence; K{sub d} values increase to >10{sup 4} above pH 12. The general surface complexation mechanism explains the sorption of these cations on PLMs.

  20. Experimental measurements of unsteady turbulent boundary layers near separation

    NASA Technical Reports Server (NTRS)

    Simpson, R. L.

    1982-01-01

    Investigations conducted to document the behavior of turbulent boundary layers on flat surfaces that separate due to adverse pressure gradients are reported. Laser and hot wire anemometers measured turbulence and flow structure of a steady free stream separating turbulent boundary layer produced on the flow of a wind tunnel section. The effects of sinusoidal and unsteadiness of the free stream velocity on this separating turbulent boundary layer at a reduced frequency were determined. A friction gage and a thermal tuft were developed and used to measure the surface skin friction and the near wall fraction of time the flow moves downstream for several cases. Abstracts are provided of several articles which discuss the effects of the periodic free stream unsteadiness on the structure or separating turbulent boundary layers.

  1. Control of flow separation in a turbulent boundary layer

    NASA Astrophysics Data System (ADS)

    Cho, Minjeong; Choi, Sangho; Choi, Haecheon

    2015-11-01

    Towards the development of successful control methods for separation delay in a turbulent boundary layer, we adopt a model flow field, in which a turbulent separation occurs above a flat plate (Na and Moin 1998 JFM), and apply controls to this flow for reducing the size of the separation bubble and investigating the interaction between the forcing and flow near the separation bubble. We provide a single-frequency forcing with zero net mass flow rate at the upstream of the separation bubble. At low forcing frequencies, spanwise vortices are generated and travel downstream, bringing high momentum toward the wall and reducing the size of the separation bubble. Also, these vortices cause the separation and reattachment points to travel downstream. On the other hand, at high forcing frequencies, the size of the separation bubble becomes smaller and larger in time, respectively, due to the pressure gradient alternating favorably and adversely in time. Supported by NRF-2011-0028032 and 2014048162.

  2. Air Flow in a Separating Laminar Boundary Layer

    NASA Technical Reports Server (NTRS)

    Schubauer, G B

    1936-01-01

    The speed distribution in a laminar boundary layer on the surface of an elliptic cylinder, of major and minor axes 11.78 and 3.98 inches, respectively, has been determined by means of a hot-wire anemometer. The direction of the impinging air stream was parallel to the major axis. Special attention was given to the region of separation and to the exact location of the point of separation. An approximate method, developed by K. Pohlhausen for computing the speed distribution, the thickness of the layer, and the point of separation, is described in detail; and speed-distribution curves calculated by this method are presented for comparison with experiment.

  3. Determination of perfluorooctanoate and perfluorooctanesulfonate in water matrices by inline matrix elimination liquid chromatography with reversed phase separation and suppressed conductivity detection.

    PubMed

    Subramanian, N Harihara; Manigandan, P; Wille, Andrea; Radhakrishnan, Ganga

    2011-09-01

    This work describes a new method for the determination of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in water matrices by suppressed conductivity detection. Separation was achieved by isocratic elution on a reversed-phase column thermostated at 45°C using an aqueous mobile phase containing boric acid and acetonitrile. The PFOA and PFOS content in the water matrix were quantified by a pre-concentration technique. For the concentration range of 1 to 15 ng/mL and 2 to 30 ng/mL, the linear calibration curve for PFOA and PFOS yielded coefficients of determination (R(2)) of 0.9995 and 0.9985, respectively. The relative standard deviations were smaller than 1.5% for PFOA and PFOS. The retention-time precision of four consecutive 12 h injections was smaller than 0.641% and 0.818%, respectively. The presence of common divalent cations, such as calcium, magnesium, and iron in water matrices impairs PFOS recovery. This drawback was overcome by applying inline matrix elimination method. The optimized method was successfully applied for drinking water, ground water, and seawater samples. PMID:21859533

  4. Effect of temperature on layer separation by plasma hydrogenation

    SciTech Connect

    Di, Z. F.; Wang, Y. Q.; Nastasi, M.; Rossi, F.; Shao, L.; Thompson, P. E.

    2008-12-22

    We have studied hydrogen diffusion in plasma hydrogenated Si/SiGe/Si heterostructure at different temperatures. At low temperature, intrinsic point defects in the molecular beam epitaxy grown Si capping layer are found to compete with the buried strain SiGe layer for hydrogen trapping. The interaction of hydrogen with point defects affects the hydrogen long-range diffusion, and restricts the amount of hydrogen available for trapping by the SiGe layer. However, hydrogen trapping by the capping layer is attenuated with increasing hydrogenation temperature allowing more hydrogen to be trapped in the strain SiGe layer with subsequent surface blister formation. A potential temperature window for plasma hydrogenation induced layer separation is identified based on the combined considerations of trap-limited diffusion at low temperature and outdiffusion of H{sub 2} molecule together with the dissociation of Si-H bonds inside of H platelet at high temperature.

  5. Effect of temperature on layer separation by plasma-hydrogenation

    SciTech Connect

    Di, Zengfeng; Michael, Nastasi A; Wang, Yongqiang

    2008-01-01

    We have studied hydrogen diffusion in plasma hydrogenated Si/SiGe/Si heterostructure at different temperatures. At low temperature, intrinsic point defects in the molecular beam epitaxy grown Si capping layer are found to compete with the buried strain SiGe layer for hydrogen trapping. The interaction of hydrogen with point defects affects the hydrogen long-range diffusion, and restricts the amount of hydrogen available for trapping by the SiGe layer. However, hydrogen trapping by the capping layer is attenuated with increasing hydrogenation temperature allowing more hydrogen to be trapped in the strain SiGe layer with subsequent surface blister formation. A potential temperature window for plasma hydrogenation induced layer separation is identified based on the combined considerations of trap-limited diffusion at low temperature and outdiffusion of H{sub 2} molecule together with the dissociation of Si-H bonds inside of H platelet at high temperature.

  6. On the theory of laminar boundary layers involving separation

    NASA Technical Reports Server (NTRS)

    Von Karman, TH; Millikan, C

    1934-01-01

    This paper presents a mathematical discussion of the laminar boundary layer, which was developed with a view of facilitating the investigation of those boundary layers in particular for which the phenomenon of separation occurs. The treatment starts with a slight modification of the form of the boundary layer equation first published by Von Mises. Two approximate solutions of this equation are found, one of which is exact at the outer edge of the boundary layer while the other is exact at the wall. The final solution is obtained by joining these two solutions at the inflection points of the velocity profiles. The final solution is given in terms of a series of universal functions for a fairly broad class of potential velocity distributions outside of the boundary layer. Detailed calculations of the boundary layer characteristics are worked out for the case in which the potential velocity is a linear function of the distance from the upstream stagnation point. Finally, the complete separation point characteristics are determined for the boundary layer associated with a potential velocity distribution made up of two linear functions of the distance from the stagnation point. It appears that extensions of the detailed calculations to more complex potential flows can be fairly easily carried out by using the explicit formulae given in the paper. (author)

  7. Double-Layered Lateral Meniscus Accompanied by Meniscocapsular Separation

    PubMed Central

    Fukuda, Aki; Nishimura, Akinobu; Nakazora, Shigeto; Kato, Ko

    2015-01-01

    We report an extremely rare case of double-layered lateral meniscus accompanied by meniscocapsular separation. The upper accessory meniscus was connected with the posterior horn and middle segment of the lower normal meniscus and was more mobile than the lower normal meniscus. A meniscocapsular separation was evident at the overlapping middle segment. Clinical symptoms were significantly improved by the resection of the upper accessory meniscus and the repair of the meniscocapsular separation. Careful arthroscopic analysis of other associated pathologies together with this rare abnormality was needed to achieve clinical improvement. PMID:26090252

  8. The numerical calculation of laminar boundary-layer separation

    NASA Technical Reports Server (NTRS)

    Klineberg, J. M.; Steger, J. L.

    1974-01-01

    Iterative finite-difference techniques are developed for integrating the boundary-layer equations, without approximation, through a region of reversed flow. The numerical procedures are used to calculate incompressible laminar separated flows and to investigate the conditions for regular behavior at the point of separation. Regular flows are shown to be characterized by an integrable saddle-type singularity that makes it difficult to obtain numerical solutions which pass continuously into the separated region. The singularity is removed and continuous solutions ensured by specifying the wall shear distribution and computing the pressure gradient as part of the solution. Calculated results are presented for several separated flows and the accuracy of the method is verified. A computer program listing and complete solution case are included.

  9. Ultrafast molecule separation through layered WS(2) nanosheet membranes.

    PubMed

    Sun, Luwei; Ying, Yulong; Huang, Hubiao; Song, Zhigong; Mao, Yiyin; Xu, Zhiping; Peng, Xinsheng

    2014-06-24

    Two-dimensional layered materials have joined in the family of size-selective separation membranes recently. Here, chemically exfoliated tungsten disulfide (WS2) nanosheets are assembled into lamellar thin films and explored as an ultrafast separation membrane for small molecules with size of about 3 nm. Layered WS2 membranes exhibit 5- and 2-fold enhancement in water permeance of graphene oxide membranes and MoS2 laminar membranes with similar rejection, respectively. To further increase the water permeance, ultrathin nanostrands are used as templates to generate more fluidic channel networks in the WS2 membrane. The water permeation behavior and separation performance in the pressure loading-unloading process reveal that the channels created by the ultrathin nanostrands are cracked under high pressure and result in a further 2-fold increase of the flux without significantly degrading the rejection for 3 nm molecules. This is supported by finite-element-based mechanical simulation. These layered WS2 membranes demonstrate up to 2 orders of magnitude higher separation performance than that of commercial membranes with similar rejections and hold the promising potential for water purification. PMID:24853383

  10. Blow-up and control of marginally separated boundary layers.

    PubMed

    Braun, Stefan; Kluwick, Alfred

    2005-05-15

    Interactive solutions for steady two-dimensional laminar marginally separated boundary layers are known to exist up to a critical value Gamma(c) of the controlling parameter (e.g. the angle of attack of a slender airfoil) Gamma only. Here, we investigate three-dimensional unsteady perturbations of such boundary layers, assuming that the basic flow is almost critical, i.e. in the limit Gamma(c)-Gamma-->0. It is then shown that the interactive equations governing such perturbations simplify significantly, allowing, among others, a systematic study of the blow-up phenomenon observed in earlier investigations and the optimization of devices used in boundary-layer control. PMID:16105768

  11. Turbulent Boundary Layers in the Vicinity of Separation

    NASA Astrophysics Data System (ADS)

    Indinger, Thomas; Buschmann, Matthias H.; Gad-El-Hak, Mohamed

    2004-11-01

    There has been some controversy regarding the behavior of the mean velocity profile of turbulent boundary layers approaching separation. While a number of experiments show that the logarithmic law is sustained even under strong adverse-pressure-gradient and non-equilibrium conditions, other experiments and DNS results reveal that the mean velocity profile breaks down in the vicinity of separation. Measurements at TU Dresden of a decelerated, fully developed turbulent boundary layer over a smooth flat plate in a closed water channel show that the classical log law no longer describes the mean velocity in the overlap region after a certain fraction of the flow travels in the upstream direction. This finding is consistent with the physical explanation advanced by Dengel & Fernholz (J. Fluid Mech. 212, 1990) that the log law failure is caused by the first occurrence of reverse flow. Analyzing adverse-pressure-gradient turbulent boundary layer data from three independent groups, we demonstrate that the log law can be restored by replacing y^+ with a new variable depending both on the wall-normal coordinate and the reverse-flow parameter \\chi_w. This finding is of importance in cases where other complexities such as surface roughness or structured walls (riblets, dimples, etc.) are involved and a universal profile in inner variables is desired.

  12. Plasmons in spatially separated double-layer graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Bagheri, Mehran; Bahrami, Mousa

    2014-05-01

    Motivated by innovative progresses in designing multi-layer graphene nanostructured materials in the laboratory, we theoretically investigate the Dirac plasmon modes of a spatially separated double-layer graphene nanoribbon system, made up of a vertically offset armchair and metallic graphene nanoribbon pair. We find striking features of the collective excitations in this novel Coulomb correlated system, where both nanoribbons are supposed to be either intrinsic (undoped/ungated) or extrinsic (doped/gated). In the former, it is shown the low-energy acoustical and the high-energy optical plasmon modes are tunable only by the inter-ribbon charge separation. In the later, the aforementioned plasmon branches are modified by the added doping factor. As a result, our model could be useful to examine the existence of a linear Landau-undamped low-energy acoustical plasmon mode tuned via the inter-ribbon charge separation as well as doping. This study might also be utilized for devising novel quantum optical waveguides based on the Coulomb coupled graphene nanoribbons.

  13. Plasmons in spatially separated double-layer graphene nanoribbons

    SciTech Connect

    Bagheri, Mehran; Bahrami, Mousa

    2014-05-07

    Motivated by innovative progresses in designing multi-layer graphene nanostructured materials in the laboratory, we theoretically investigate the Dirac plasmon modes of a spatially separated double-layer graphene nanoribbon system, made up of a vertically offset armchair and metallic graphene nanoribbon pair. We find striking features of the collective excitations in this novel Coulomb correlated system, where both nanoribbons are supposed to be either intrinsic (undoped/ungated) or extrinsic (doped/gated). In the former, it is shown the low-energy acoustical and the high-energy optical plasmon modes are tunable only by the inter-ribbon charge separation. In the later, the aforementioned plasmon branches are modified by the added doping factor. As a result, our model could be useful to examine the existence of a linear Landau-undamped low-energy acoustical plasmon mode tuned via the inter-ribbon charge separation as well as doping. This study might also be utilized for devising novel quantum optical waveguides based on the Coulomb coupled graphene nanoribbons.

  14. Reynolds shear stress measurements in a separated boundary layer flow

    NASA Technical Reports Server (NTRS)

    Driver, David M.

    1991-01-01

    Turbulence measurements were obtained for two cases of boundary layer flow with an adverse pressure gradient, one attached and the other separated. A three-component laser Doppler velocimeter system was used to measure three mean velocity components, all six Reynolds stress components, and all ten velocity triple product correlations. Independent measurements of skin-friction obtained with a laser oil-flow interferometer were used to examine the law of the wall in adverse pressure gradient flows where p(+) is less than 0.05. Strong similiarities were seen between the two adverse pressure gradient flows and free shear layer type flows. Eddy viscosities, dissipation rates, and pressure-strain rates were deduced from the data and compared to various turbulence modeling assumptions.

  15. Polymer coatings as separator layers for microbial fuel cell cathodes

    NASA Astrophysics Data System (ADS)

    Watson, Valerie J.; Saito, Tomonori; Hickner, Michael A.; Logan, Bruce E.

    2011-03-01

    Membrane separators reduce oxygen flux from the cathode into the anolyte in microbial fuel cells (MFCs), but water accumulation and pH gradients between the separator and cathode reduces performance. Air cathodes were spray-coated (water-facing side) with anion exchange, cation exchange, and neutral polymer coatings of different thicknesses to incorporate the separator into the cathode. The anion exchange polymer coating resulted in greater power density (1167 ± 135 mW m-2) than a cation exchange coating (439 ± 2 mW m-2). This power output was similar to that produced by a Nafion-coated cathode (1114 ± 174 mW m-2), and slightly lower than the uncoated cathode (1384 ± 82 mW m-2). Thicker coatings reduced oxygen diffusion into the electrolyte and increased coulombic efficiency (CE = 56-64%) relative to an uncoated cathode (29 ± 8%), but decreased power production (255-574 mW m-2). Electrochemical characterization of the cathodes ex situ to the MFC showed that the cathodes with the lowest charge transfer resistance and the highest oxygen reduction activity produced the most power in MFC tests. The results on hydrophilic cathode separator layers revealed a trade off between power and CE. Cathodes coated with a thin coating of anion exchange polymer show promise for controlling oxygen transfer while minimally affecting power production.

  16. Circular Hydraulic Jumps Triggered by Boundary Layer Separation.

    PubMed

    Chang; Demekhin; Takhistov

    2001-01-15

    When a high-flow-rate circular jet impinges vertically on a horizontal plane, it flows out radially and then undergoes a distinctive hydraulic jump on the plane because of boundary layer separation induced by hydrostatic back pressure. The jump radius is shown to be 0.37 a Re(1/3) Lambda(-1/8), where Lambda=(ga(3)/nu(2)) Re(-7/3) is a modified Froude number, Re=(Q/anu) is the jet Reynolds number, a is the jet radius, and Q the liquid flow rate, which is favorably compared to experimental data in the limit of small Lambda. When Lambda exceeds 3.0x10(-4) at low flow rates, the jump radius decreases below a minimum in the film depth and our experiments detect a different jump mechanism that may be triggered by capillary pressure rather than hydrostatic pressure. Copyright 2001 Academic Press. PMID:11121283

  17. Near-wall turbulence modeling for boundary layers with separation

    NASA Astrophysics Data System (ADS)

    Ko, S. H.

    1991-12-01

    As a turbulent boundary layer undergoes a strong adverse pressure gradient, the flow may separate from the wall, and the use of empirical wall functions is inappropriate. The turbulence transport equations as well as the momentum equations must be solved through the laminar sublayer to the wall. The laminar sublayer encompasses a region where viscous effects become increasingly important. For the past two decades, many proposals for near-wall turbulence models of the kappa-epsilon type have been presented for calculating near-wall flows. A thorough review and a systematic evaluation of these models was previously given. It was found that some of the models tested failed to reproduce even the simple flat-plate boundary layer flow. Overall, the authors concluded that the near-wall turbulence models needed further refinement if they were to be used with confidence to calculate near-wall flows. Recently, the use of a direct numerical simulation (DNS) data base has provided new insight and data for development and testing of near-wall turbulence models.

  18. Calculation of shock-separated turbulent boundary layers

    NASA Technical Reports Server (NTRS)

    Baldwin, B. S.; Rose, W. C.

    1975-01-01

    Numerical solutions of the complete, time-averaged conservation equations using several eddy-viscosity models for the Reynolds shear stress to close the equations are compared with experimental measurements in a compressible, turbulent separated flow. An efficient time-splitting, explicit difference scheme was used to solve the two-dimensional conservation equations. The experiment used for comparison was a turbulent boundary layer that was separated by an incident shock wave in a Mach 2.93 flow with a unit Reynolds number of 5.7 x 10 to the seventh power m. Comparisons of predicted and experimental values of surface pressure, shear stress along the wall, and velocity profiles are shown. One of the tested eddy-viscosity models which allows the shear stress to be out of equilibrium with the mean flow produces substantially better agreement with the experimental measurements than the simpler models. A tool is thereby provided for inferring additional information about the flow, such as static pressures in the stream, which might not be directly obtainable from experiments.

  19. Comparison of several methods for predicting separation in a compressible turbulent boundary layer

    NASA Technical Reports Server (NTRS)

    Gerhart, P. M.; Bober, L. J.

    1974-01-01

    Several methods for predicting the separation point for a compressible turbulent boundary layer were applied to the flow over a bump on a wind-tunnel wall. Measured pressure distributions were used as input. Two integral boundary-layer methods, three finite-difference boundary-layer methods, and three simple methods were applied at five free-stream Mach numbers ranging from 0.354 to 0.7325. Each of the boundary-layer methods failed to explicitly predict separation. However, by relaxing the theoretical separation criteria, several boundary-layer methods were made to yield reasonable separation predictions, but none of the methods accurately predicted the important boundary-layer parameters at separation. Only one of the simple methods consistently predicted separation with reasonable accuracy in a manner consistent with the theory. The other methods either indicated several possible separation locations or only sometimes predicted separation.

  20. Experimental and numerical investigation of the coherent flow structures around tandem in-line surface-mounted cubes in a thin boundary layer

    NASA Astrophysics Data System (ADS)

    Havel, Brian

    The flow around two interfering surface-mounted cubes of height, H, in a thin boundary layer was experimentally and numerically investigated as a function of the obstacle spacing, S, at a Reynolds number of Re H = 22,000 in a thin boundary layer. The mutual aerodynamic interference between the two surface-mounted cubes is described in terms of changes in vortex shedding frequency and in terms of changes in the mean and turbulent field structures. Mean, instantaneous and phase-averaged velocity data from Laser Doppler Velocimetry (LDV) and surface pressure data were analysed to characterize three flow regimes. The studies were complemented by surface pattern and laser-sheet visualizations. The results were compared to the two-dimensional counterpart of this flow. Based on vortex shedding behaviour, it had been established that four distinct flow regimes exist: "one-body", bi-stable, lock-in, and quasi-isolated. For short spacings S/H<1.5, the shear layer separating at the leading edge of the upstream obstacle reattaches on the sides of the second obstacle giving rise to two intermittent modes of oscillations. For this mechanism to occur it is suggested that sufficient circulation must freely enter the gap, which is not the case for the 2D geometry. To broaden the understanding of the lock-in regime, 1.5< S/H<2.3, detailed LES simulations were conducted. The LES predicted the Strouhal number correctly, as well as the macroscopic and turbulent features of the flow field. It had been shown using phase-averaging that the vortex shedding is not like the traditional Karman type of mechanism. Instead the top shear layer from the first cube interferes with the vortex formation and triggers shedding. The result is a streamwise shed vortex that can be traced into the wake of the second obstacle on its opposite side. Using the LDV measurements and LES simulations it has been shown that an arch-shaped vortex dominates the inter-obstacle cavity. Keywords. Vortex shedding, two

  1. On the use of Lagrangian variables in descriptions of unsteady boundary-layer separation

    NASA Technical Reports Server (NTRS)

    Cowley, Stephen J.; Vandommelen, Leon L.; Lam, Shui T.

    1990-01-01

    The Lagrangian description of unsteady boundary layer separation is reviewed from both analytical and numerical perspectives. It is explained in simple terms how particle distortion gives rise to unsteady separation, and why a theory centered on Lagrangian coordinates provides the clearest description of this phenomenon. Some of the more recent results for unsteady three dimensional compressible separation are included. The different forms of separation that can arise from symmetries are emphasized. A possible description of separation is also included when the detaching vorticity layer exits the classical boundary layer region, but still remains much closer to the surface than a typical body-lengthscale.

  2. Membranes having aligned 1-D nanoparticles in a matrix layer for improved fluid separation

    DOEpatents

    Revanur, Ravindra; Lulevich, Valentin; Roh, Il Juhn; Klare, Jennifer E.; Kim, Sangil; Noy, Aleksandr; Bakajin, Olgica

    2015-12-22

    Membranes for fluid separation are disclosed. These membranes have a matrix layer sandwiched between an active layer and a porous support layer. The matrix layer includes 1-D nanoparticles that are vertically aligned in a porous polymer matrix, and which substantially extend through the matrix layer. The active layer provides species-specific transport, while the support layer provides mechanical support. A matrix layer of this type has favorable surface morphology for forming the active layer. Furthermore, the pores that form in the matrix layer tend to be smaller and more evenly distributed as a result of the presence of aligned 1-D nanoparticles. Improved performance of separation membranes of this type is attributed to these effects.

  3. Control and reduction of unsteady pressure loads in separated shock wave turbulent boundary layer interaction

    NASA Technical Reports Server (NTRS)

    Dolling, David S.; Barter, John W.

    1995-01-01

    The focus was on developing means of controlling and reducing unsteady pressure loads in separated shock wave turbulent boundary layer interactions. Section 1 describes how vortex generators can be used to effectively reduce loads in compression ramp interaction, while Section 2 focuses on the effects of 'boundary-layer separators' on the same interaction.

  4. Categories and calculations of three-dimensional boundary-layer-separation

    NASA Astrophysics Data System (ADS)

    Nishikawa, N.

    The three-dimensional boundary layer separation is characterized and its numerical calculation is discussed. The three-dimensional boundary layer separation is defined according to envelope and skin friction line theories. Flow separations behind the hatch-back car, are analyzed and applications of nose-coordinate to a parabolic body, use of the ZIG-ZAG scheme, and evaluation of the characteristic box scheme are studied.

  5. Development of Techniques for Separating Waterproof Layer from XLPE Cable Sheath by Hot Water Heating

    NASA Astrophysics Data System (ADS)

    Okazaki, Masato; Nakade, Masahiko; Okashita, Minoru; Tanimoto, Mihoko

    Waterproof layer is used to prevent penetration of water which is one of the factors of dielectric breakdown in XLPE cables more than 66kV class. A XLPE cable sheath with waterproof layer is done landfill disposal as industrial waste because separation of waterproof layer is difficult for technology and cost. However, around 20 years passes after waterproof layer was introduced, and social consciousness for environment changes during these 20 years, and responsibility of company for environment of a society grows bigger. We report the result that examined techniques for separating waterproof layer.

  6. Experimental detection of a periodically forced turbulent boundary layer separation

    NASA Astrophysics Data System (ADS)

    Chabert, Timothée; Dandois, Julien; Garnier, Eric; Jacquin, Laurent

    2013-02-01

    Wind tunnel experiments are conducted to investigate the effect of periodic blowing over a non-slotted NACA-type flap equipped with seven pulsed slots. The tests are performed at Re ≃ 3 × 106 for different deflection angles ranging from 2° to 35°. Wall-mounted hot-films are chordwise distributed on the flap. The purpose of the experiments is to assess the ability of wall shear stress signals to detect flow separation with and without periodic control, and to be used as reliable feedback information in a closed-loop control framework. Laser beam tomoscopy is first used to visualize flow structures with and without flow control. Two separation criteria based on higher-order statistical moments of hot-film signals are proposed to detect flow separation. They present the advantage of being independent of the free-stream velocity. The two criteria are finally practised to follow the steady-state response of the system and determine its static map local gradient.

  7. Fabrication of triple layered vascular scaffolds by combining electrospinning, braiding, and thermally induced phase separation

    NASA Astrophysics Data System (ADS)

    Mi, Hao-Yang; Jing, Xin; Yu, Emily; McNulty, Jason; Turng, Lih-Sheng

    2015-12-01

    Triple layered small diameter vascular scaffolds, which consisted of thermoplastic polyurethane (TPU) and silk, were fabricated in this study for the first time by combining electrospinning, braiding, and thermally induced phase separation methods. These novel vascular scaffolds, which possess three layers of different structures (nanofibrous inner layer, woven silk filament middle layer, and porous outer layer) have a desired toe region in the tensile test and sufficient suture retention and burst pressure for vascular graft applications. The endothelia cell culture tests showed that a cell layer could form on the inner surface of a scaffold with high cell viability. Furthermore, the cells showed favorable morphology on the scaffold.

  8. The efficient simulation of separated three-dimensional viscous flows using the boundary-layer equations

    NASA Technical Reports Server (NTRS)

    Van Dalsem, W. R.; Steger, J. L.

    1985-01-01

    A simple and computationally efficient algorithm for solving the unsteady three-dimensional boundary-layer equations in the time-accurate or relaxation mode is presented. Results of the new algorithm are shown to be in quantitative agreement with detailed experimental data for flow over a swept infinite wing. The separated flow over a 6:1 ellipsoid at angle of attack, and the transonic flow over a finite-wing with shock-induced 'mushroom' separation are also computed and compared with available experimental data. It is concluded that complex, separated, three-dimensional viscous layers can be economically and routinely computed using a time-relaxation boundary-layer algorithm.

  9. Confined phase separation in SiOX nanometric thin layers

    NASA Astrophysics Data System (ADS)

    Roussel, M.; Talbot, E.; Pareige, C.; Pratibha Nalini, R.; Gourbilleau, F.; Pareige, P.

    2013-11-01

    Phase separation in silicon-rich silica/silica multilayers was investigated using Atom Probe Tomography and Atomistic Kinetic Monte Carlo simulation. It is shown that the thickness of silicon-rich silicon oxide sublayers plays an important role during phase transformation. It determines the morphology of Si-rich phase formed after subsequent annealing, which is of prime interest for microelectronic and optoelectronic applications. Monte Carlo simulation reveals that the formation of isolated Si clusters can be achieved even in the case of spinodal decomposition and is directly related to the ratio between the spinodal wavelength and the sublayer thickness.

  10. Prediction of Laminar and Turbulent Boundary Layer Flow Separation in V/STOL Engine Inlets

    NASA Technical Reports Server (NTRS)

    Chou, D. C.; Luidens, R. W.; Stockman, N. O.

    1977-01-01

    A description is presented of the development of the boundary layer on the lip and diffuser surface of a subsonic inlet at arbitrary operating conditions of mass flow rate, free stream velocity and incidence angle. Both laminar separation on the lip and turbulent separation in the diffuser are discussed. The agreement of the theoretical results with model experimental data illustrates the capability of the theory to predict separation. The effects of throat Mach number, inlet size, and surface roughness on boundary layer development and separation are illustrated.

  11. Prediction of laminar and turbulent boundary layer flow separation in V/STOL engine inlets

    NASA Technical Reports Server (NTRS)

    Chou, D. C.; Luidens, R. W.; Stockman, N. O.

    1977-01-01

    The paper provides a theoretical description of the development of the boundary layer on the lip and diffuser surface of a subsonic inlet at arbitrary operating conditions of mass flow rate, freestream velocity and incidence angle. Both laminar separation on the lip and turbulent separation in the diffuser are discussed. The agreement of the theoretical results with model experimental data illustrates the capability of the theory to predict separation. The effects of throat Mach number, inlet size, and surface roughness on boundary-layer development and separation are illustrated.

  12. Radionuclide separations using pillared layered materials. Final report

    SciTech Connect

    Clearfield, A.

    1995-08-31

    The objective of this project is to prepare an all inorganic strontium specific sorbent or ion exchanger for the removal of highly alkaline nuclear waste solutions. A series of clays and layered titanates were pillared and calcined to convert their essentially two dimensional structure to three dimensional porous structures with high surface areas. The pillaring agents were alumina, zirconia, chromia and silica based. The pillared clays, particularly those containing Zr pillars, achieved moderate (Kd as high at 13,700 ml/g with V:m = 28) selectivities for Sr{sup 2+}. In contrast, the silica pillared titanates showed exceptional affinities for Sr{sup 2+} with Kd values in excess of 100,000 ml/g in 5M NaNO{sup 3} + 1M NaOH. These latter results suggest a more detailed study of the pillared titanates in the presence of simulants closely resembling real waste solutions.

  13. Mechanically durable, superoleophobic coatings prepared by layer-by-layer technique for anti-smudge and oil-water separation

    NASA Astrophysics Data System (ADS)

    Brown, Philip S.; Bhushan, Bharat

    2015-03-01

    Superoleophobic surfaces are of interest for anti-fouling, self-cleaning, anti-smudge, low-drag, anti-fog, and oil-water separation applications. Current bioinspired surfaces are of limited use due to a lack of mechanical durability. A so-called layer-by-layer approach, involving charged species with electrostatic interactions between layers, can provide the flexibility needed to improve adhesion to the substrate while providing a low surface tension coating at the air interface. In this work, a polyelectrolyte binder, SiO2 nanoparticles, and a fluorosurfactant are spray deposited separately to create a durable, superoleophobic coating. Polydiallyldimethylammonium chloride (PDDA) polyelectrolyte was complexed with a fluorosurfactant layer (FL), which provides oil repellency while being hydrophilic. This oleophobic/superhydrophilic behavior was enhanced through the use of roughening with SiO2 particles resulting in a superoleophobic coating with hexadecane contact angles exceeding 155° and tilt angles of less than 4°. The coating is also superhydrophilic, which is desirable for oil-water separation applications. The durability of these coatings was examined through the use of micro- and macrowear experiments. These coatings currently display characteristics of transparency. Fabrication of these coatings via the layer-by-layer technique results in superoleophobic surfaces displaying improved durability compared to existing work where either the durability or the oil-repellency is compromised.

  14. Mechanically durable, superoleophobic coatings prepared by layer-by-layer technique for anti-smudge and oil-water separation.

    PubMed

    Brown, Philip S; Bhushan, Bharat

    2015-01-01

    Superoleophobic surfaces are of interest for anti-fouling, self-cleaning, anti-smudge, low-drag, anti-fog, and oil-water separation applications. Current bioinspired surfaces are of limited use due to a lack of mechanical durability. A so-called layer-by-layer approach, involving charged species with electrostatic interactions between layers, can provide the flexibility needed to improve adhesion to the substrate while providing a low surface tension coating at the air interface. In this work, a polyelectrolyte binder, SiO2 nanoparticles, and a fluorosurfactant are spray deposited separately to create a durable, superoleophobic coating. Polydiallyldimethylammonium chloride (PDDA) polyelectrolyte was complexed with a fluorosurfactant layer (FL), which provides oil repellency while being hydrophilic. This oleophobic/superhydrophilic behavior was enhanced through the use of roughening with SiO2 particles resulting in a superoleophobic coating with hexadecane contact angles exceeding 155° and tilt angles of less than 4°. The coating is also superhydrophilic, which is desirable for oil-water separation applications. The durability of these coatings was examined through the use of micro- and macrowear experiments. These coatings currently display characteristics of transparency. Fabrication of these coatings via the layer-by-layer technique results in superoleophobic surfaces displaying improved durability compared to existing work where either the durability or the oil-repellency is compromised. PMID:25731716

  15. Mechanically durable, superoleophobic coatings prepared by layer-by-layer technique for anti-smudge and oil-water separation

    PubMed Central

    Brown, Philip S.; Bhushan, Bharat

    2015-01-01

    Superoleophobic surfaces are of interest for anti-fouling, self-cleaning, anti-smudge, low-drag, anti-fog, and oil-water separation applications. Current bioinspired surfaces are of limited use due to a lack of mechanical durability. A so-called layer-by-layer approach, involving charged species with electrostatic interactions between layers, can provide the flexibility needed to improve adhesion to the substrate while providing a low surface tension coating at the air interface. In this work, a polyelectrolyte binder, SiO2 nanoparticles, and a fluorosurfactant are spray deposited separately to create a durable, superoleophobic coating. Polydiallyldimethylammonium chloride (PDDA) polyelectrolyte was complexed with a fluorosurfactant layer (FL), which provides oil repellency while being hydrophilic. This oleophobic/superhydrophilic behavior was enhanced through the use of roughening with SiO2 particles resulting in a superoleophobic coating with hexadecane contact angles exceeding 155° and tilt angles of less than 4°. The coating is also superhydrophilic, which is desirable for oil-water separation applications. The durability of these coatings was examined through the use of micro- and macrowear experiments. These coatings currently display characteristics of transparency. Fabrication of these coatings via the layer-by-layer technique results in superoleophobic surfaces displaying improved durability compared to existing work where either the durability or the oil-repellency is compromised. PMID:25731716

  16. Improvements to in-line desalting of oligosaccharides separated by high-pH anion exchange chromatography with pulsed amperometric detection.

    PubMed

    Thayer, J R; Rohrer, J S; Avdalovic, N; Gearing, R P

    1998-02-15

    High-pH anion exchange chromatography with pulsed amperometric detection (HPAEC/PAD) (1) is routinely used to separate neutral and charged oligosaccharides differing by branch, linkage, and positional isomerism. Oligosaccharides are eluted in 0.1 M NaOH with gradients of sodium acetate (up to 0.25 M). Analyses of HPAEC/PAD-purified oligosaccharides generally require neutralization and removal of eluent salts. To facilitate the process, we designed and produced a cation-exchange system to remove sodium ions (Na+) from the eluent after oligosaccharide detection [the Carbohydrate Membrane Desalter (CMD), with a volatile regenerant]. Exchange of >99.5% of eluent Na+ for hydronium ions (H3O+) within the CMD generates dilute acetic acid (removable by vacuum evaporation). The exchange process desalts up to 0.35 M Na+ at 1.0 ml/min. Oligosaccharides collected after on-line desalting, evaporated and resuspended in their original volume of deionized water contained < or = 350 muM residual Na+ when the eluting sodium concentration was 300 mM. This represents a desalting efficiency of >99.8%. Recovery of neutral and sialylated oligosaccharides under these conditions ranged from 75 to 100%. With the CMD system and postcollection evaporation, HPAEC/PAD can purify oligosaccharides ready for further characterization. As a proof test, oligosaccharides from a human monoclonal antibody were separated by HPAEC/PAD, desalted with the CMD system, dried, and analyzed by matrix-assisted laser desorption-ionization, time-of-flight mass spectrometry. PMID:9473279

  17. 30 CFR 57.22210 - In-line filters (I-C mines).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false In-line filters (I-C mines). 57.22210 Section... Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22210 In-line filters (I-C mines). Filters or separators shall be installed on air-lift fan systems to prevent explosive concentrations...

  18. 30 CFR 57.22210 - In-line filters (I-C mines).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false In-line filters (I-C mines). 57.22210 Section... Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22210 In-line filters (I-C mines). Filters or separators shall be installed on air-lift fan systems to prevent explosive concentrations...

  19. 30 CFR 57.22210 - In-line filters (I-C mines).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false In-line filters (I-C mines). 57.22210 Section... Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22210 In-line filters (I-C mines). Filters or separators shall be installed on air-lift fan systems to prevent explosive concentrations...

  20. 30 CFR 57.22210 - In-line filters (I-C mines).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false In-line filters (I-C mines). 57.22210 Section... Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22210 In-line filters (I-C mines). Filters or separators shall be installed on air-lift fan systems to prevent explosive concentrations...

  1. Separated shear-layer instability reproduction by a Reynolds stress model of turbulence

    NASA Astrophysics Data System (ADS)

    Jakirlic, Suad; Maduta, Robert

    2013-11-01

    A boundary layer separating from a solid wall transforms into a `separated shear layer' exhibiting a broader frequency range. Such a highly-unsteady shear layer separating the mean stream from the flow reversal is dominated by the organized, large-scale coherent structures, influencing to a large extent the overall flow behavior. Unlike in the case of a flat-plate boundary layer separating at a fixed point characterizing a backward-facing step geometry, which can be reasonably well captured by a statistical model of turbulence, the separation process pertinent to continuous curved surfaces as well as some fence- or rib-shaped configurations is beyond the reach of any RANS (Reynolds-Averaged Navier Stokes) model independent of the modeling level. The latter issue motivated the present work, dealing with an appropriate extension of a near-wall Second-Moment Closure (SMC) model towards an instability-sensitive formulation. The production term in the corresponding scale-supplying equation is selectively enhanced through introduction of the ratio of the first to the second derivative of the velocity field, the latter representing the integral part of the von Karman length scale, enabling appropriate capturing of the fluctuating turbulence and accordingly the reproduction of the separated shear-layer instability. The analysis is performed by simulating the flow separated from a fence, an axisymmetric hill and a cylinder configuration.

  2. THIN-LAYER SEPARATION OF CITRIC ACID CYCLE INTERMEDIATES, LACTIC ACID, AND THE AMINO ACID TAURINE

    EPA Science Inventory

    This paper describes a two-dimensional mixed-layer method for separating citric acid cycle intermediates, lactic acid and the amino acid taurine. The method cleanly separates all citric acid cycle intermediates tested, excepting citric acid and isocitric acid. The solvents are in...

  3. Three-dimensional separation for interaction of shock waves with turbulent boundary layers

    NASA Technical Reports Server (NTRS)

    Goldberg, T. J.

    1973-01-01

    For the interaction of shock waves with turbulent boundary layers, obtained experimental three-dimensional separation results and correlations with earlier two-dimensional and three-dimensional data are presented. It is shown that separation occurs much earlier for turbulent three-dimensional than for two-dimensional flow at hypersonic speeds.

  4. Ion Layer Separation and Equilibrium Zonal Winds in Midlatitude Sporadic E

    NASA Technical Reports Server (NTRS)

    Earle, G. D.; Kane, T. J.; Pfaff, R. F.; Bounds, S. R.

    2000-01-01

    In-situ observations of a moderately strong mid-latitude sporadic-E layer show a separation in altitude between distinct sublayers composed of Fe(+), Mg(+), and NO(+). From these observations it is possible to estimate the zonal wind field consistent with diffusive equilibrium near the altitude of the layer. The amplitude of the zonal wind necessary to sustain the layer against diffusive effects is less than 10 meters per second, and the vertical wavelength is less than 10 km.

  5. Shock-induced separation of adiabatic turbulent boundary layers in supersonic axially symmetric internal flow

    NASA Technical Reports Server (NTRS)

    Page, R. J.; Childs, M. E.

    1974-01-01

    An experimental investigation at Mach 4 of shock-induced turbulent boundary layer separation at the walls of axially symmetric flow passages is discussed, with particular emphasis placed on determining the shock strengths required for incipient separation. The shock waves were produced by interchangeable sting-mounted cones placed on the axes of the flow passages and aligned with the freestream flow. The interactions under study simulate those encountered in axially symmetric engine inlets of supersonic aircraft. Knowledges of the shock strengths required for boundary layer separation in inlets is important since for shocks of somewhat greater strength rather drastic alterations in the inlet flow field may occur.

  6. Measurements in Separated and Transitional Boundary Layers Under Low-Pressure Turbine Airfoil Conditions

    NASA Technical Reports Server (NTRS)

    Volino, Ralph J.; Hultgren, Lennart .

    2000-01-01

    Detailed velocity measurements were made along a flat plate subject to the same dimensionless pressure gradient as the suction side of a modern low-pressure turbine airfoil. Reynolds numbers based on wetted plate length and nominal exit velocity were varied from 50,000 to 300,000, covering cruise to takeoff conditions. Low and high inlet free-stream turbulence intensities (0.2% and 7%) were set using passive grids. The location of boundary-layer separation does not depend strongly on the free-stream turbulence level or Reynolds number, as long as the boundary layer remains non-turbulent prior to separation. Strong acceleration prevents transition on the upstream part of the plate in all cases. Both free-stream turbulence and Reynolds number have strong effects on transition in the adverse pressure gradient region. Under low free-stream turbulence conditions transition is induced by instability waves in the shear layer of the separation bubble. Reattachment generally occurs at the transition start. At Re = 50,000 the separation bubble does not close before the trailing edge of the modeled airfoil. At higher Re, transition moves upstream, and the boundary layer reattaches. With high free-stream turbulence levels, transition appears to occur in a bypass mode, similar to that in attached boundary layers. Transition moves upstream, resulting in shorter separation regions. At Re above 200,000, transition begins before separation. Mean velocity, turbulence and intermittency profiles are presented.

  7. Investigation of supersonic turbulent boundary-layer separation on a compression ramp by an integral method

    NASA Technical Reports Server (NTRS)

    Patel, D. K.; Czarnecki, K. R.

    1977-01-01

    An investigation was made to determine the feasibility of using a boundary layer integral method to study the separation of a turbulent boundary layer on a two dimensional ramp at supersonic speeds. The numerical calculations were made for a free stream Mach number of 3, a Reynolds number of 10 million, and over a ramp angle range from 0 deg to 30 deg. For ramp angles where no flow separation was indicated, theoretical calculations were in reasonable agreement with experimental data except for a somewhat belated rise in pressure. For larger ramp angles, where separation was present, the investigation produced results that were not in agreement with experiment or with results calculated by time dependent Navier-Stokes methods. This apparently was true because no provision had been made for a proper shock boundary layer interaction where strong normal pressure gradients are induced within the boundary layer under the shock independent of surface curvature effects.

  8. Numerical computation of unsteady laminar boundary layers with separation using two-parameter integral method

    NASA Astrophysics Data System (ADS)

    Akamatsu, T.; Matsushita, M.; Murata, S.

    1985-11-01

    A two-parameter integral method is presented which is applicable even to separated boundary layers. The governing equation system, which consists of three moment equations of the boundary layer equation, is shown to be classifiable as a quasi-linear hyperbolic system under the assumed velocity profile function. The governing system is numerically solved by a dissipative finite difference scheme in order to capture a discontinuous solution associated with the singularity of unsteady separation. The spontaneous generation of singularity associated with unsteady separation is confirmed as the focusing of characteristics. The starting flows of a circular and an elliptic cylinder are considered as definite examples. This method is found to give excellent results in comparison with exact methods, not only for practically important boundary layer quantities such as displacement thickness or skin friction coefficient, but also for generation of separation singularity.

  9. Turbulence characteristics of separated boundary layer flow under unsteady pressure gradients using direct numerical simulation

    NASA Astrophysics Data System (ADS)

    Park, Junshin; Bromby, William; You, Donghyun

    2013-11-01

    To understand turbulence characteristics of separated boundary layer flow under unsteady pressure gradients, a direct numerical simulation study is performed. Steady and unsteady blowing-suction velocity distributions are imposed along the upper boundary of the computational domain to introduce steady and unsteady adverse pressure gradients leading to steady and unsteady separated turbulent boundary layers, respectively. Time averaged and phase averaged turbulence statistics such as velocity, vorticity, kinetic energy budgets, Reynolds stress budgets, wall pressure fluctuations and skin friction distributions are examined in detail with aims of gaining understanding of flow physics for unsteady separated turbulent boundary layer and the sources of incapability of the conventional Reynolds-averaged Navier-Stokes models in predicting unsteady separation. Supported by the Army Research Office Grant W911NF1010348 and the National Research Foundation of Korea Grant NRF-2012R1A1A2003699.

  10. Inverse solutions for laminar boundary-layer flows with separation and reattachment

    NASA Technical Reports Server (NTRS)

    Carter, J. E.

    1975-01-01

    Numerical solutions of the laminar, incompressible boundary layer equations are presented for flows involving separation and reattachment. Regular solutions are obtained with an inverse approach in which either the displacement thickness or the skin friction is specified; the pressure is deduced from the solution. A vorticity-stream-function formulation of the boundary layer equations is used to eliminate the unknown pressure. Solutions of the resulting finite difference equations, in which the flow direction is taken into account, are obtained by several global iteration schemes which are stable and have unconditional diagonal dominance. Results are compared with Klineberg and Steger's separated boundary layer calculations, and with Briley's solution of Navier-Stokes equations for a separated region. In addition, an approximate technique is presented in which the streamwise convection of vorticity is set equal to zero in the reversed flow region; such a technique results in a quick forward marching procedure for separated flows.

  11. Injection slot location for boundary-layer control in shock-induced separation

    NASA Technical Reports Server (NTRS)

    Viswanath, P. R.; Sankaran, L.; Sagdeo, P. M.; Narasimha, R.; Prabhu, A.

    1978-01-01

    An experimental investigation of the effect of tangential air injection, when the injection slot is located inside of what would otherwise have been the dead air zone in a separated flow, in controlling shock-induced turbulent boundary layer separation is presented. The experiments were carried out at a free-stream Mach number of 2.5 in the separated flow induced by a compression corner with a 20 deg angle. The observations made were wall static pressures, pitot profiles, and schlieren visualizations of the flow. The results show that the present location for injection is more effective in suppressing boundary-layer separation than the more conventional one, where the slot is located upstream of where separation would occur in the absence of injection.

  12. Boundary-layer separation on isolated boattail nozzles. M.S. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Abeyounis, W. K.

    1978-01-01

    An angle of attack of 0 deg was investigated in the Langley 16 foot transonic tunnel at free-stream Mach numbers from 0.40 to 0.95 to study the phenomenon of separated flow on a series of circular-arc afterbodies. Both high-pressure air and solid circular cylinders with the cylinder diameter equal to the nozzle-exit diameter were used to simulate jet exhausts. The results indicate that boundary-layer separation is most extensive on steep boattails at high Mach numbers. The jet total-pressure ratio changes (jet total pressure to free-stream static pressure) affected the extent of separation very little; however, comparison of the separation data obtained by using the two jet-simulation techniques indicate that entrainment associated with the presence of a jet had a significant effect on the extent of separation. The solid-simulator separation data were also used to evaluate the predictions of eight separation criteria.

  13. Electric Double-Layer Effects Induce Separation of Aqueous Metal Ions.

    PubMed

    Ji, Qinghua; An, Xiaoqiang; Liu, Huijuan; Guo, Lin; Qu, Jiuhui

    2015-11-24

    Metal ion separation is crucial to environmental decontamination, chromatography, and metal recovery and recycling. Theoretical studies have suggested that the ion distributions in the electric double-layer (EDL) region depend on the nature of the ions and the characteristics of the charged electrode surface. We believe that rational design of the electrode material and device structure will enable EDL-based devices to be utilized in the separation of aqueous metal ions. On the basis of this concept, we fabricate an EDL separation (EDLS) device based on sandwich-structured N-functionalized graphene sheets (CN-GS) for selective separation of aqueous toxic heavy metal ions. We demonstrate that the EDLS enables randomly distributed soluble ions to form a coordination-driven layer and electrostatic-driven layer in the interfacial region of the CN-GS/solution. Through tuning the surface potential of the CN-GS, the effective separation of heavy metal ions (coordination-driven layer) from alkali or alkaline earth metal ions (electrostatic-driven layer) can be achieved. PMID:26481603

  14. In-line hydraulic dashpot

    NASA Astrophysics Data System (ADS)

    Moody, Paul E.

    1992-10-01

    An in-line hydraulic dashpot is disclosed that effectively decelerates the piston of a power cylinder by controllably choking off the oil which is providing pressure to the piston. The in-line hydraulic dashpot of the invention includes a valve spool member movable between an open and closed position along a fluid flow path that supplies oil to the power cylinder. An actuator rod is cooperative with the valve spool member and the piston shaft of the power cylinder to move tile valve spool member between its open and closed positions. The in-line hydraulic dashpot eliminates the clashing of mechanical parts and therewith eliminates the noise that would otherwise be generated thereby. The in-line hydraulic dashpot of the present invention makes possible the adaptation of a fixed stroke power cylinder to applications that call for a variable stroke length.

  15. Turbine airfoil with dual wall formed from inner and outer layers separated by a compliant structure

    DOEpatents

    Campbell; Christian X. , Morrison; Jay A.

    2011-12-20

    A turbine airfoil usable in a turbine engine with a cooling system and a compliant dual wall configuration configured to enable thermal expansion between inner and outer layers while eliminating stress formation is disclosed. The compliant dual wall configuration may be formed a dual wall formed from inner and outer layers separated by a compliant structure. The compliant structure may be configured such that the outer layer may thermally expand without limitation by the inner layer. The compliant structure may be formed from a plurality of pedestals positioned generally parallel with each other. The pedestals may include a first foot attached to a first end of the pedestal and extending in a first direction aligned with the outer layer, and may include a second foot attached to a second end of the pedestal and extending in a second direction aligned with the inner layer.

  16. Solutions for incompressible separated boundary layers including viscous-inviscid interaction

    NASA Technical Reports Server (NTRS)

    Carter, J. E.; Wornom, S. F.

    1975-01-01

    Numerical solutions are presented for the laminar and turbulent boundary-layer equations for incompressible flows with separation and reattachment. The separation angularity is avoided by using an inverse technique in which the displacement thickness is prescribed and the pressure is deduced from the resulting solution. The turbulent results appear qualitatively correct despite the use of a two-layer eddy-viscosity model which is generally assumed appropriate only for mild-pressure-gradient flows. A new viscous-inviscid interaction technique is presented in which the inviscid flow is solved inversely by prescribing the pressure from the boundary-layer solution and deducing the new displacement thickness from the solution of a Cauchy integral. Calculations are presented using this interaction procedure for a laminar flow in which separation and reattachment occur on a solid surface.

  17. On the Lagrangian description of unsteady boundary layer separation. Part 2: The spinning sphere

    NASA Technical Reports Server (NTRS)

    Vandommelen, Leon L.

    1989-01-01

    A theory to explain the initial stages of unsteady separation was proposed by Van Dommelen and Cowley (1989). This theory is verified for the separation process that occurs at the equatorial plane of a sphere or a spheroid which is impulsively spun around an axis of symmetry. A Lagrangian numerical scheme is developed which gives results in good agreement with Eulerian computations, but which is significantly more accurate. This increased accuracy, and a simpler structure to the solution, also allows verification of the Eulerian structure, including the presence of logarithmic terms. Further, while the Eulerian computations broke down at the first occurrence of separation, it is found that the Lagrangian computation can be continued. It is argued that this separated solution does provide useful insight into the further evolution of the separated flow. A remarkable conclusion is that an unseparated vorticity layer at the wall, a familiar feature in unsteady separation processes, disappears in finite time.

  18. On the Lagrangian description of unsteady boundary-layer separation. II - The spinning sphere

    NASA Technical Reports Server (NTRS)

    Van Dommelen, Leon L.

    1990-01-01

    A theory to explain the initial stages of unsteady separation was proposed by Van Dommelen and Cowley (1989). This theory is verified for the separation process that occurs at the equatorial plane of a sphere or a spheroid which is impulsively spun around an axis of symmetry. A Lagrangian numerical scheme is developed which gives results in good agreement with Eulerian computations, but which is significantly more accurate. This increased accuracy, and a simpler structure to the solution, also allows verification of the Eulerian structure, including the presence of logarithmic terms. Further, while the Eulerian computations broke down at the first occurrence of separation, it is found that the Lagrangian computation can be continued. It is argued that this separated solution does provide useful insight into the further evolution of the separated flow. A remarkable conclusion is that an unseparated vorticity layer at the wall, a familiar feature in unsteady separation processes, disappears in finite time.

  19. Numerical investigation of three-dimensional flow separation using the boundary layer equations

    NASA Technical Reports Server (NTRS)

    Wie, Yong-Sun; Dejarnette, Fred R.

    1988-01-01

    The steady, incompressible, three-dimensional laminar and turbulent boundary-layer equations are solved in a streamline coordinate system and in a self-adaptive grid system using Matsuno's finite difference method. Techniques are described for calculating laminar and turbulent separation using the boundary-layer equations. Any type (bubble type or free vortex-layer type) of major separation line can be calculated at an angle of attack on ellipsoids of revolution by this boundary layer code. Results are presented for ellipsoids of revolution at angles of attack up to 45 degrees. Agreements with other numerical and experimental results are very good for laminar flows. Turbulent flows are also investigated with algebraic turbulence models proposed by Rotta and Cebeci and Smith. Good agreement with experimental results was obtained at a small angle of attack (10 degrees) but only qualitative agreement was obtained at a high angle of attack (30 degrees) for turbulent flow on a 6:1 ellipsoid of revolution.

  20. Modifications of the law of the wall and algebraic turbulence modelling for separated boundary layers

    NASA Technical Reports Server (NTRS)

    Baldwin, B. S.; Maccormack, R. W.

    1976-01-01

    Various modifications of the conventional algebraic eddy viscosity turbulence model are investigated for application to separated flows. Friction velocity is defined in a way that avoids singular behavior at separation and reattachment but reverts to the conventional definition for flows with small pressure gradients. This leads to a modified law of the wall for separated flows. The effect on the calculated flow field of changes in the model that affect the eddy viscosity at various distances from the wall are determined by (1) switching from Prandtl's form to an inner layer formula due to Clauser at various distances from the wall, (2) varying the constant in the Van Driest damping factor, (3) using Clauser's inner layer formula all the way to the wall, and (4) applying a relaxation procedure in the evaluation of the constant in Clauser's inner layer formula. Numerical solutions of the compressible Navier-Stokes equations are used to determine the effects of the modifications. Experimental results from shock-induced separated flows at Mach numbers 2.93 and 8.45 are used for comparison. For these cases improved predictions of wall pressure distribution and positions of separation and reattachment are obtained from the relaxation version of the Clauser inner layer eddy viscosity formula.

  1. Laminar and turbulent boundary layer separation control of Mako shark skin

    NASA Astrophysics Data System (ADS)

    Afroz, Farhana

    The Shortfin Mako shark (Isurus oxyrinchus) is one of the fastest swimmers in nature. They have an incredible turning agility and are estimated to achieve speeds as high as ten body lengths per second. Shark skin is known to contain flexible denticles or scales, capable of being actuated by the flow whereby a unique boundary layer control (BLC) method could reduce drag. It is hypothesized that shark scales bristle when the flow is reversed, and this bristling may serve to control flow separation by (1) inhibiting the localized flow reversal near the wall and (2) inducing mixing within the boundary layer by cavities formed between the scales that increases the momentum of the flow near the wall. To test this hypothesis, samples of Mako shark skin have been studied under various amounts of adverse pressure gradient (APG). These samples were collected from the flank region of a Shortfin Mako shark where the scales have the greatest potential for separation control due to the highest bristling angles. An easy technique for inducing boundary layer separation has been developed where an APG can be generated and varied using a rotating cylinder. Both the experimental and numerical studies showed that the amount of APG can be varied as a function of cylinder rotation speed or cylinder gap height for a wide range of Reynolds numbers. This method of generating an APG is used effectively for inducing both laminar and turbulent boundary layer separation over a flat plate. Laminar and turbulent boundary layer separation studies conducted over a smooth plate have been compared with the same setup repeated over shark skin. The time-averaged DPIV results showed that shark scale bristling controlled both laminar and turbulent boundary layer separation to a measurable extent. It shows that the shark scales cause an early transition to turbulence and reduce the degree of laminar separation. For turbulent separation, reverse flow near the wall and inside the boundary layer is

  2. A contour-line color layer separation algorithm based on fuzzy clustering and region growing

    NASA Astrophysics Data System (ADS)

    Liu, Tiange; Miao, Qiguang; Xu, Pengfei; Tong, Yubing; Song, Jianfeng; Xia, Ge; Yang, Yun; Zhai, Xiaojie

    2016-03-01

    The color layers of contour-lines separated from scanned topographic map are the basis of contour-line extraction, but it is difficult to separate them well due to the color aliasing and mixed color problems. This paper will focus us on contour-line color layer separation and presents a novel approach for it based on fuzzy clustering and Single-prototype Region Growing for Contour-line Layer (SRGCL). The purpose of this paper is to provide a solution for processing scanned topographic maps on which contour-lines are abundant and densely distributed, for example, in the condition similar to hilly areas and mountainous regions, the contour-lines always occupy the largest proportion in linear features and the contour-line separation is the most difficult task. The proposed approach includes steps as follows. First step, line features are extracted from the map to reduce the interference from area features in fuzzy clustering. Second step, fuzzy clustering algorithm is employed to obtain membership matrix of pixels in the line map. Third step, based on the membership matrix, we obtain the most-similar prototype and the second-similar prototype of each pixel as the indicators of the pixel in SRGCL. The spatial relationship and the fuzzy similarity of color features are used in SRGCL to overcome the inaccurate classification of ambiguous pixels. The procedure focusing on single contour-line layer will improve the accuracy of contour-line segmentation result of SRGCL relative to general segmentation methods. We verified the algorithm on several USGS historical maps, the experimental results show that our algorithm produces contour-line color layers with good continuity and few noises, which verifies the improvement in contour-line color layer separation of our algorithm relative to two general segmentation methods.

  3. Comparison Between Navier-Stokes and Thin-Layer Computations for Separated Supersonic Flow

    NASA Technical Reports Server (NTRS)

    Degani, David; Steger, Joseph L.

    1983-01-01

    In the numerical simulation of high Reynolds-number flow, one can frequently supply only enough grid points to resolve the viscous terms in a thin layer. As a consequence, a body-or stream-aligned coordinate system is frequently used and viscous terms in this direction are discarded. It is argued that these terms cannot be resolved and computational efficiency is gained by their neglect. Dropping the streamwise viscous terms in this manner has been termed the thin-layer approximation. The thin-layer concept is an old one, and similar viscous terms are dropped, for example, in parabolized Navier-Stokes schemes. However, such schemes also make additional assumptions so that the equations can be marched in space, and such a restriction is not usually imposed on a thin-layer model. The thin-layer approximation can be justified in much the same way as the boundary-layer approximation; it requires, therefore, a body-or stream-aligned coordinate and a high Reynolds number. Unlike the boundary-layer approximation, the same equations are used throughout, so there is no matching problem. Furthermore, the normal momentum equation is not simplified and the convection terms are not one-sided differenced for marching. Consequently, the thin-layer equations are numerically well behaved at separation and require no special treatment there. Nevertheless, the thin-layer approximation receives criticism. It has been suggested that the approximation is invalid at separation and, more recently, that it is inadequate for unsteady transonic flow. Although previous comparisons between the thin-layer and Navier-Stokes equations have been made, these comparisons have not been adequately documented.

  4. Heat Transfer at the Reattachment Zone of Separated Laminar Boundary Layers

    NASA Technical Reports Server (NTRS)

    Chung, Paul M.; Viegas, John R.

    1961-01-01

    The flow and heat transfer are analyzed at the reattachment zone of two-dimensional separated laminar boundary layers. The fluid is considered to be flowing normal to the wall at reattachment. An approximate expression is derived for the heat transfer in the reattachment region and a calculated value is compared with an experimental measurement.

  5. Thin-Layer Chromatographic Separation of Phenols: An Undergraduate Laboratory Experiment.

    ERIC Educational Resources Information Center

    Kurth, Mark J.

    1986-01-01

    Background information, procedures used, and equipment needed are provided for an experiment in which a series of readily available, inexpensive, and relatively nontoxic phenols are separated using thin-layer chromatographic techniques. The experiment permits a discussion of how relative Rf values may be rationalized by considering a molecule's…

  6. Effects of boundary-layer separation controllers on a desktop fume hood.

    PubMed

    Huang, Rong Fung; Chen, Jia-Kun; Hsu, Ching Min; Hung, Shuo-Fu

    2016-10-01

    A desktop fume hood installed with an innovative design of flow boundary-layer separation controllers on the leading edges of the side plates, work surface, and corners was developed and characterized for its flow and containment leakage characteristics. The geometric features of the developed desktop fume hood included a rearward offset suction slot, two side plates, two side-plate boundary-layer separation controllers on the leading edges of the side plates, a slanted surface on the leading edge of the work surface, and two small triangular plates on the upper left and right corners of the hood face. The flow characteristics were examined using the laser-assisted smoke flow visualization technique. The containment leakages were measured by the tracer gas (sulphur hexafluoride) detection method on the hood face plane with a mannequin installed in front of the hood. The results of flow visualization showed that the smoke dispersions induced by the boundary-layer separations on the leading edges of the side plates and work surface, as well as the three-dimensional complex flows on the upper-left and -right corners of the hood face, were effectively alleviated by the boundary-layer separation controllers. The results of the tracer gas detection method with a mannequin standing in front of the hood showed that the leakage levels were negligibly small (≤0.003 ppm) at low face velocities (≥0.19 m/s). PMID:27104797

  7. Knuckleball and Flying Disk: Boundary Layer Transitions, Separations and Vortex Wakes in Sports Aerodynamics

    NASA Astrophysics Data System (ADS)

    Higuchi, Hiroshi; Kiura, Toshiro; Goto, Yuichiro; Hiramoto, Riho

    2001-11-01

    In spite of their popularity, flow structures over common baseball and flying disks have not been studied in detail. A slowly rotating baseball is subject to erratic flight paths, and is known as a knuckleball. In the present experiment, the characteristic of force acting on a baseball was obtained and the velocity vector field near the surface of the ball and the wake were measured with the DPIV technique. The seam triggered the boundary layer transition or caused the boundary layer separation itself. The laminar/turbulent boundary layer separations were identified with specific ball orientations. Corresponding three-dimensional wake pattern and the side force result in unpredictable trajectories. In the second part of the talk, flow physics regarding a spin-stabilized flying disk is addressed. The roll-up of trailing vortices was visualized in detail and their vorticity field was measured with the DPIV. The vortical flow over the disk produced flow reattachment at a very high angle of attack. The boundary layer at low angles of attack was affected by the surface motion with asymmetric boundary layer transitions as evidenced by the flow visualization and the hot wire survey. The flow separation and attachment on the underside cavity were also affected by the rotation.

  8. Double-Layer Magnetic Nanoparticle-Embedded Silica Particles for Efficient Bio-Separation

    PubMed Central

    Kang, Homan; Cho, Hong-Jun; Park, Sung-Jun; Yang, Jin-Kyoung; Kim, Sehoon; Kim, Hyung-Mo; Jun, Bong-Hyun; Lee, Yoon-Sik

    2015-01-01

    Superparamagnetic Fe3O4 nanoparticles (NPs) based nanomaterials have been exploited in various biotechnology fields including biomolecule separation. However, slow accumulation of Fe3O4 NPs by magnets may limit broad applications of Fe3O4 NP-based nanomaterials. In this study, we report fabrication of Fe3O4 NPs double-layered silica nanoparticles (DL MNPs) with a silica core and highly packed Fe3O4 NPs layers. The DL MNPs had a superparamagnetic property and efficient accumulation kinetics under an external magnetic field. Moreover, the magnetic field-exposed DL MNPs show quantitative accumulation, whereas Fe3O4 NPs single-layered silica nanoparticles (SL MNPs) and silica-coated Fe3O4 NPs produced a saturated plateau under full recovery of the NPs. DL MNPs are promising nanomaterials with great potential to separate and analyze biomolecules. PMID:26599084

  9. Turbine blade boundary layer separation suppression via synthetic jet: An experimental and numerical study

    NASA Astrophysics Data System (ADS)

    Bernardini, C.; Carnevale, M.; Manna, M.; Martelli, F.; Simoni, D.; Zunino, P.

    2012-10-01

    The present paper focuses on the analysis of a synthetic jet device (with a zero net massflow rate) on a separated boundary layer. Separation has been obtained on a flat plate installed within a converging-diverging test section specifically designed to attain a local velocity distribution typical of a high-lift LPT blade. Both experimental and numerical investigations have been carried out. Unsteady RANS results have been compared with experiments in terms of time-averaged velocity and turbulence intensity distributions. Two different Reynolds number cases have been investigated, namely Re = 200, 000 and Re = 70, 000, which characterize low-pressure turbine operating conditions during take-off/landing and cruise. A range of synthetic jet aerodynamic parameters (Strouhal number and blowing ratio) has been tested in order to analyze the features of control — separated boundary layer interaction for the aforementioned Reynolds numbers.

  10. Interacting boundary-layer solutions for laminar separated flow past airfoils

    NASA Technical Reports Server (NTRS)

    Burggraf, O. R.

    1984-01-01

    Numerical solutions of the interacting laminar boundary layer equations are presented for two symmetric airfoils at zero incidence: the NACA 0012 and the NACA 66 sub 3-108 airfoils. The potential flow was computed using Carlson's code, and viscous interaction was treated following a Hilbert integral scheme due to Veldman. Effects of various grid parameters are studied, and pressure and skin friction distributions are compared at several Reynolds numbers. For the NACA 0012 airfoil, Reynolds number is varied from a value just below separation (R sub N = 3000) to a value for which extensive separation occurs (R sub N = 100,000). For the 66 sub 3-018 airfoil, results are given at intermediate values (R sub N - 10,000 and 40,000). The method fails to converge for greater values of Reynolds number, corresponding to the development of very thin well separated shear layers where transition to turbulence would occur naturally.

  11. Spontaneous reconnection at a separator current layer: 1. Nature of the reconnection

    NASA Astrophysics Data System (ADS)

    Stevenson, J. E. H.; Parnell, C. E.

    2015-12-01

    Magnetic separators, which lie on the boundary between four topologically distinct flux domains, are prime locations in three-dimensional magnetic fields for reconnection, especially in the magnetosphere between the planetary and interplanetary magnetic fields and also in the solar atmosphere. Little is known about the details of separator reconnection, and so the aim of this paper, which is the first of two, is to study the properties of magnetic reconnection at a single separator. Three-dimensional, resistive magnetohydrodynamic numerical experiments are run to study separator reconnection starting from a magnetohydrostatic equilibrium which contains a twisted current layer along a single separator linking a pair of opposite-polarity null points. The resulting reconnection occurs in two phases. The first is short involving rapid reconnection in which the current at the separator is reduced by a factor of around 2.3. Most (75%) of the magnetic energy is converted during this phase, via Ohmic dissipation, directly into internal energy, with just 0.1% going into kinetic energy. During this phase the reconnection occurs along most of the separator away from its ends (the nulls) but in an asymmetric manner which changes both spatially and temporally over time. The second phase is much longer and involves slow impulsive bursty reconnection. Again, Ohmic heating dominates over viscous damping. Here the reconnection occurs in small localized bursts at random anywhere along the separator.

  12. Controlling turbulent boundary layer separation using biologically inspired 2D transverse grooves

    NASA Astrophysics Data System (ADS)

    Lang, Amy; Jones, Emily; Afroz, Farhana

    2013-11-01

    It is theorized that the presence of grooves, such as the sinusoidal ones found on dolphin skin or the cavities that form between bristled shark skin scales, can lead to induced boundary layer mixing and result in the control of turbulent boundary layer separation. To test this hypothesis, a series of water tunnel experiments using DPIV studied the characteristics of a flat plate turbulent boundary layer whereby a rotating cylinder was used to induce an adverse pressure gradient and resulting flow separation. The experiments were repeated with the use of a plate covered with two types of grooves, rectangular and sinusoidal, with a spacing of 2 mm in size. Flow similarity of the cavity flow was preserved between the experiments and flow over bristled shark skin scales. Both geometries resulted in a reduction of flow separation as measured by backflow coefficient. In addition, Reynolds stress profiles showed that as the pressure gradient was increased, the sinusoidal geometry outperformed the rectangular grooves in terms of increased mixing close to the wall. The sinusoidal plate also generated a lower momentum deficit within the boundary layer which would indicate a smaller drag penalty. Support from NSF grant CBET 0932352 and a UA Graduate Council Fellowship is gratefully acknowledged.

  13. On the Lagrangian description of unsteady boundary-layer separation. I - General theory

    NASA Technical Reports Server (NTRS)

    Van Dommelen, Leon L.; Cowley, Stephen J.

    1990-01-01

    Although unsteady, high-Reynolds number, laminar boundary layers have conventionally been studied in terms of Eulerian coordinates, a Lagrangian approach may have significant analytical and computational advantages. In Lagrangian coordinates the classical boundary layer equations decouple into a momentum equation for the motion parallel to the boundary, and a hyperbolic continuity equation (essentially a conserved Jacobian) for the motion normal to the boundary. The momentum equations, plus the energy equation if the flow is compressible, can be solved independently of the continuity equation. Unsteady separation occurs when the continuity equation becomes singular as a result of touching characteristics, the condition for which can be expressed in terms of the solution of the momentum equations. The solutions to the momentum and energy equations remain regular. Asymptotic structures for a number of unsteady 3-D separating flows follow and depend on the symmetry properties of the flow. In the absence of any symmetry, the singularity structure just prior to separation is found to be quasi 2-D with a displacement thickness in the form of a crescent shaped ridge. Physically the singularities can be understood in terms of the behavior of a fluid element inside the boundary layer which contracts in a direction parallel to the boundary and expands normal to it, thus forcing the fluid above it to be ejected from the boundary layer.

  14. On the Lagrangian description of unsteady boundary layer separation. Part 1: General theory

    NASA Technical Reports Server (NTRS)

    Vandommelen, Leon L.; Cowley, Stephen J.

    1989-01-01

    Although unsteady, high-Reynolds number, laminar boundary layers have conventionally been studied in terms of Eulerian coordinates, a Lagrangian approach may have significant analytical and computational advantages. In Lagrangian coordinates the classical boundary layer equations decouple into a momentum equation for the motion parallel to the boundary, and a hyperbolic continuity equation (essentially a conserved Jacobian) for the motion normal to the boundary. The momentum equations, plus the energy equation if the flow is compressible, can be solved independently of the continuity equation. Unsteady separation occurs when the continuity equation becomes singular as a result of touching characteristics, the condition for which can be expressed in terms of the solution of the momentum equations. The solutions to the momentum and energy equations remain regular. Asymptotic structures for a number of unsteady 3-D separating flows follow and depend on the symmetry properties of the flow. In the absence of any symmetry, the singularity structure just prior to separation is found to be quasi 2-D with a displacement thickness in the form of a crescent shaped ridge. Physically the singularities can be understood in terms of the behavior of a fluid element inside the boundary layer which contracts in a direction parallel to the boundary and expands normal to it, thus forcing the fluid above it to be ejected from the boundary layer.

  15. Flowfield measurements in a separated and reattached flat plate turbulent boundary layer

    NASA Technical Reports Server (NTRS)

    Patrick, William P.

    1987-01-01

    The separation and reattachment of a large-scale, two-dimensional turbulent boundary layer at low subsonic speed on a flat plate has been studied experimentally. The separation bubble was 55 cm long and had a maximum bubble thickness, measured to the height of the mean dividing streamline, of 17 cm, which was twice the thickness of the inlet boundary layer. A combination of laser velocimetry, hot-wire anemometry, pneumatic probing techniques, and flow visualization were used as diagnostics. Principal findings were that an outer inviscid rotational flow was defined which essentially convected over the blockage associated with the inner, viscously dominated bubble recirculation region. A strong backflow region in which the flow moved upstream 100 percent of the time was measured near the test surface over the central 35 percent of the bubble. A laminar backflow boundary layer having pseudo-turbulent characteristics including a log-linear velocity profile was generated under the highly turbulent backflow. Velocity profile shapes in the reversed flow region matched a previously developed universal backflow profile at the upstream edge of the separation region but not in the steady backflow region downstream. A smoke flow visualization movie and hot-film measurements revealed low frequency nonperiodic flapping at reattachment. However, forward flow fraction data at reattachment and mean velocity profiles in the redeveloping boundary layer downstream of reattachment correlated with backward-facing step data when the axial dimension was scaled by the distance from the maximum bubble thickness to reattachment.

  16. Boundary layer separation method for recycling of sodium ions from industrial wastewater.

    PubMed

    Petho, Dóra; Horváth, Géza; Liszi, János; Tóth, Imre; Paor, Dávid

    2010-12-01

    The most effective technological solution for waste treatment is recycling. We have developed a new method for the treatment of industrial wastewaters and have called it the boundary layer separation method (BLSM). We have used the phenomenon that, on the surface of an electrically charged electrode, ions can be enriched in the boundary layer, as compared with the inside of the phase. The essence of the method is that, with an appropriately chosen velocity, the boundary layer can be removed from the wastewater, and the boundary layer, which is rich in ions, can be recycled. The BLSM can be executed as a cyclic procedure. The capacitance of the boundary layer was examined. The best mass transport can be achieved with the use of 1000 and 1200 mV polarization potentials in the examined system, with its value being 1200 mg/m2 per cycle. The necessary operation times were determined by the examination of the velocity of the electrochemical processes. When using 1000 mV polarization potential, the necessary adsorption time is at least 25 seconds, and the desorption time at least 300 seconds. The advantage of the procedure is that it does not use dangerous chemicals, only inert electrodes. The drawback is that it is not selective to ions, the achievable separation in one step is low, and the hydrogen that emerges during the electrolysis might be dangerous. PMID:21214032

  17. Functional separator consisted of polyimide nonwoven fabrics and polyethylene coating layer for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Shi, Chuan; Zhang, Peng; Huang, Shaohua; He, Xinyi; Yang, Pingting; Wu, Dezhi; Sun, Daoheng; Zhao, Jinbao

    2015-12-01

    In this paper, a composite membrane with nonwoven polyimide (PI) membrane as structural support and polyethylene (PE) particles coating layer as a thermal shutdown layer, is fabricated as the separator for lithium-ion battery. Different from PI nonwoven membrane, the PE coating PI nonwoven composite membrane (PE-PI-S) not only shows excellent thermal shutdown function, similar to traditional multilayer PP/PE/PP separator, but also exhibits much higher thermal stability, better wettability to the polar electrolyte and lower internal resistance than the PP/PE/PP separator. The electrolyte uptake and ionic conductivity of PE-PI-S increase from 58%, 0.84 mS cm-1 to 400%, 1.34 mS cm-1, respectively. Furthermore, the thermal shutdown function of PE-PI-S can be controlled widely in the temperature range from 120 °C to more than 200 °C while the multilayer PP/PE/PP separator only with a shutdown temperature range from 130 °C to 160 °C. Lithium ion battery with PE-PI-S nonwoven separator also shows excellent stable cycling and good rate performance.

  18. Use of multiple discrete wall jets for delaying boundary layer separation

    NASA Technical Reports Server (NTRS)

    Mclean, J. D.; Herring, H. J.

    1974-01-01

    The effectiveness of a spanwise array of small discrete blowing nozzles in preventing separation of a turbulent boundary layer was investigated experimentally. The spacing, axial location, and momentum flux of the nozzles were varied in a systematic way, and overall performance was measured for each combination. Extensive mean velocity profiles were measured for one selected combination. Overall diffusion achieved before separation was correlated successfully with a momentum flux excess parameter, and in terms of this parameter discrete nozzles, when advantageously placed, were found to perform somewhat better than an optimally placed two-dimensional jet slot.

  19. The behaviour of a compressible turbulent boundary layer under incipient separation conditions

    NASA Technical Reports Server (NTRS)

    Muck, K. C.; Smits, A. J.

    1984-01-01

    This paper presents an experimental study of a turbulent boundary-layer/shock-wave interaction. The interaction was generated by a two-dimensional compression corner, and the flow was on the point of separating. Measurements were made using both normal and inclined hot wires, and the data include measurements of the longitudinal mass-flow fluctuation intensity and the mass-weighted Reynolds shear stress.

  20. The effect of thin liquid films on boundary-layer separation

    NASA Astrophysics Data System (ADS)

    Cimpeanu, Radu; Papageorgiou, Demetrios; Kravtsova, Marina; Ruban, Anatoly

    2015-11-01

    In this study we develop the theory for understanding the process of boundary-layer separation in the presence of a thin liquid film. The investigation is physically motivated by the accumulation of water on aircraft surfaces as a result of flying during adverse weather conditions, with implications in aircraft safety, certification and performance. We present an extension of the asymptotic framework of viscous-inviscid interaction and formulate a modified triple-deck model accounting for the strong density and viscosity contrast between the fluids in the system. The primary goal of the study is to address the question of whether the thin liquid layer acts to suppress or promote boundary-layer separation. We find that an increase in liquid film height (within its asymptotic scaling) contributes to a delay in the onset of separation. Furthermore, the main flow features, represented by local extrema in the perturbed flow quantities, are shifted further downstream within the interaction region. The consequences of the presence of the liquid film are illustrated through two typical examples encountered in flows past aircraft wings, namely surface roughness elements and corners/flap junctions.

  1. A documentation of two- and three-dimensional shock-separated turbulent boundary layers

    NASA Technical Reports Server (NTRS)

    Brown, J. D.; Brown, J. L.; Kussoy, M. I.

    1988-01-01

    A shock-related separation of a turbulent boundary layer has been studied and documented. The flow was that of an axisymmetric turbulent boundary layer over a 5.02-cm-diam cylinder that was aligned with the wind tunnel axis. The boundary layer was compressed by a 30 deg half-angle conical flare, with the cone axis inclined at an angle alpha to the cylinder axis. Nominal test conditions were P sub tau equals 1.7 atm and M sub infinity equals 2.85. Measurements were confined to the upper-symmetry, phi equals 0 deg, plane. Data are presented for the cases of alpha equal to 0. 5. and 10 deg and include mean surface pressures, streamwise and normal mean velocities, kinematic turbulent stresses and kinetic energies, as well as reverse-flow intermittencies. All data are given in tabular form; pressures, streamwise velocities, turbulent shear stresses, and kinetic energies are also presented graphically.

  2. Control of Shock-Induced Boundary Layer Separation by using Pulsed Plasma Jets

    NASA Astrophysics Data System (ADS)

    Greene, Benton R.; Clemens, Noel T.; Micka, Daniel

    2012-11-01

    Shock-induced turbulent boundary layer separation can have many detrimental effects in supersonic flow including flow instability, fatigue of structural panels, and unstart in supersonic inlets. Pulsed plasma jets (or ``spark jets''), which are characterized by high bandwidth and the ability to direct momentum into the flow, are one promising method of reducing shock-induced separation. The current study is focused on investigating the efficacy of plasma jets to reduce the separated flow induced by a compression ramp in a Mach 3 flow. Three different 3-jet actuator configurations are tested: 20° pitched, 45° pitched, and 22° pitched and 45° skewed. The jets are pulsed at frequencies between 2 kHz and 4 kHz with duty cycles between 5 and 15%. The shock wave is generated using a 20° compression ramp, and the location of the shock-induced separation is visualized using surface oil streak visualization as well as particle image velocimetry. The results of the study show that of the three configurations, the plasma jets pitched at 20° from the streamwise direction cause the greatest reduction in separation, and when pulsed at a frequency of 3.2 kHz and 12% duty cycle can reduce the size of the separation region by up to 40%. This work is supported by AFRL under SBIR contract.

  3. A multi-layered approach for absorptive glass-mat separators

    NASA Astrophysics Data System (ADS)

    Ferreira, A. L.

    The traditional method of manufacturing absorptive glass mats (AGMs) for valve-regulated lead-acid (VRLA) batteries is to blend two or more types of fibres together in an aqueous acidic solution and deposit this blend on to either a moving endless wire or a roto-former (another version of an endless wire). The sheet acquires consistency as the water is withdrawn; it is then pressed and dried against heated drums. The methods of fibre dispersion and deposition can be changed so that the different constituent fibre types of an AGM separator are processed separately in distinct and separate layers. This fibre segregation results in the enhancement of some key characteristics of the separator and thus brings some very definite advantages to the performance of VRLA batteries, e.g., the ability to deliver higher currents at higher discharge rates. Also, important AGM characteristics, such as wicking, porosity/pore-size and stratification, are radically modified by adoption of the multi-layered AGM design. As a consequence, the high-rate and cycling performances of VRLA batteries are equally affected.

  4. Boundary Layer Separation and Reattachment Detection on Airfoils by Thermal Flow Sensors

    PubMed Central

    Sturm, Hannes; Dumstorff, Gerrit; Busche, Peter; Westermann, Dieter; Lang, Walter

    2012-01-01

    A sensor concept for detection of boundary layer separation (flow separation, stall) and reattachment on airfoils is introduced in this paper. Boundary layer separation and reattachment are phenomena of fluid mechanics showing characteristics of extinction and even inversion of the flow velocity on an overflowed surface. The flow sensor used in this work is able to measure the flow velocity in terms of direction and quantity at the sensor's position and expected to determine those specific flow conditions. Therefore, an array of thermal flow sensors has been integrated (flush-mounted) on an airfoil and placed in a wind tunnel for measurement. Sensor signals have been recorded at different wind speeds and angles of attack for different positions on the airfoil. The sensors used here are based on the change of temperature distribution on a membrane (calorimetric principle). Thermopiles are used as temperature sensors in this approach offering a baseline free sensor signal, which is favorable for measurements at zero flow. Measurement results show clear separation points (zero flow) and even negative flow values (back flow) for all sensor positions. In addition to standard silicon-based flow sensors, a polymer-based flexible approach has been tested showing similar results. PMID:23202160

  5. Investigation of Shock-Induced Laminar Separation Bubble in a Supersonic Boundary Layer

    NASA Astrophysics Data System (ADS)

    Sivasubramanian, Jayahar; Fasel, Hermann

    2015-11-01

    The interaction between an impinging oblique shock and a laminar boundary-layer on a flat plate is investigated using DNS. In particular, the two-dimensional separation bubble resulting from the shock/boundary-layer interaction (SBLI) at freestream Mach number of 2.0 is investigated in detail. The flow parameters used for the present investigation match the laboratory conditions in the experiments by Hakkinen et al. The skin friction and pressure distribution from the simulations are compared to the experimental measurements and numerical results available in the literature. Our results confirm the asymmetric nature of the separation bubble as reported in the literature. In addition to the steady flow field calculations, the response to low-amplitude disturbances is investigated in order to study the linear stability behavior of the separation bubble. For comparison, both the development of two-dimensional and three-dimensional (oblique) disturbances are studied with and without the impinging oblique shock. Furthermore, the effects of the shock incidence angle and Reynolds number are also investigated. Finally, three-dimensional simulations were performed in order to explore the laminar-turbulent transition process in the presence of a laminar separation bubble. Funded by the Air Force Office of Scientific Research under grant FA9550-14-1-0195.

  6. Boundary layer separation and reattachment detection on airfoils by thermal flow sensors.

    PubMed

    Sturm, Hannes; Dumstorff, Gerrit; Busche, Peter; Westermann, Dieter; Lang, Walter

    2012-01-01

    A sensor concept for detection of boundary layer separation (flow separation, stall) and reattachment on airfoils is introduced in this paper. Boundary layer separation and reattachment are phenomena of fluid mechanics showing characteristics of extinction and even inversion of the flow velocity on an overflowed surface. The flow sensor used in this work is able to measure the flow velocity in terms of direction and quantity at the sensor's position and expected to determine those specific flow conditions. Therefore, an array of thermal flow sensors has been integrated (flush-mounted) on an airfoil and placed in a wind tunnel for measurement. Sensor signals have been recorded at different wind speeds and angles of attack for different positions on the airfoil. The sensors used here are based on the change of temperature distribution on a membrane (calorimetric principle). Thermopiles are used as temperature sensors in this approach offering a baseline free sensor signal, which is favorable for measurements at zero flow. Measurement results show clear separation points (zero flow) and even negative flow values (back flow) for all sensor positions. In addition to standard silicon-based flow sensors, a polymer-based flexible approach has been tested showing similar results. PMID:23202160

  7. Modified Separator Using Thin Carbon Layer Obtained from Its Cathode for Advanced Lithium Sulfur Batteries.

    PubMed

    Liu, Naiqiang; Huang, Bicheng; Wang, Weikun; Shao, Hongyuan; Li, Chengming; Zhang, Hao; Wang, Anbang; Yuan, Keguo; Huang, Yaqin

    2016-06-29

    The realization of a practical lithium sulfur battery system, despite its high theoretical specific capacity, is severely limited by fast capacity decay, which is mainly attributed to polysulfide dissolution and shuttle effect. To address this issue, we designed a thin cathode inactive material interlayer modified separator to block polysulfides. There are two advantages for this strategy. First, the coating material totally comes from the cathode, thus avoids the additional weights involved. Second, the cathode inactive material modified separator improve the reversible capacity and cycle performance by combining gelatin to chemically bond polysulfides and the carbon layer to physically block polysulfides. The research results confirm that with the cathode inactive material modified separator, the batteries retain a reversible capacity of 644 mAh g(-1) after 150 cycles, showing a low capacity decay of about 0.11% per circle at the rate of 0.5C. PMID:27267483

  8. Active control of Boundary Layer Separation & Flow Distortion in Adverse Pressure Gradient Flows via Supersonic Microjets

    NASA Technical Reports Server (NTRS)

    Alvi, Farrukh S.; Gorton, Susan (Technical Monitor)

    2005-01-01

    Inlets to aircraft propulsion systems must supply flow to the compressor with minimal pressure loss, flow distortion or unsteadiness. Flow separation in internal flows such as inlets and ducts in aircraft propulsion systems and external flows such as over aircraft wings, is undesirable as it reduces the overall system performance. The aim of this research has been to understand the nature of separation and more importantly, to explore techniques to actively control this flow separation. In particular, the use of supersonic microjets as a means of controlling boundary layer separation was explored. The geometry used for the early part of this study was a simple diverging Stratford ramp, equipped with arrays of supersonic microjets. Initial results, based on the mean surface pressure distribution, surface flow visualization and Planar Laser Scattering (PLS) indicated a reverse flow region. We implemented supersonic microjets to control this separation and flow visualization results appeared to suggest that microjets have a favorable effect, at least to a certain extent. However, the details of the separated flow field were difficult to determine based on surface pressure distribution, surface flow patterns and PLS alone. It was also difficult to clearly determine the exact influence of the supersonic microjets on this flow. In the latter part of this study, the properties of this flow-field and the effect of supersonic microjets on its behavior were investigated in further detail using 2-component (planar) Particle Image Velocimetry (PIV). The results clearly show that the activation of microjets eliminated flow separation and resulted in a significant increase in the momentum of the fluid near the ramp surface. Also notable is the fact that the gain in momentum due to the elimination of flow separation is at least an order of magnitude larger (two orders of magnitude larger in most cases) than the momentum injected by the microjets and is accomplished with very

  9. Phase-separated, epitaxial composite cap layers for electronic device applications and method of making the same

    DOEpatents

    Aytug, Tolga; Paranthaman, Mariappan Parans; Polat, Ozgur

    2012-07-17

    An electronic component that includes a substrate and a phase-separated layer supported on the substrate and a method of forming the same are disclosed. The phase-separated layer includes a first phase comprising lanthanum manganate (LMO) and a second phase selected from a metal oxide (MO), metal nitride (MN), a metal (Me), and combinations thereof. The phase-separated material can be an epitaxial layer and an upper surface of the phase-separated layer can include interfaces between the first phase and the second phase. The phase-separated layer can be supported on a buffer layer comprising a composition selected from the group consisting of IBAD MgO, LMO/IBAD-MgO, homoepi-IBAD MgO and LMO/homoepi-MgO. The electronic component can also include an electronically active layer supported on the phase-separated layer. The electronically active layer can be a superconducting material, a ferroelectric material, a multiferroic material, a magnetic material, a photovoltaic material, an electrical storage material, and a semiconductor material.

  10. Characterization of an incipiently separated shock wave/turbulent boundary layer interaction

    NASA Astrophysics Data System (ADS)

    Schreyer, A.-M.; Dussauge, J.-P.; Krämer, E.

    2016-05-01

    The turbulence structure in a shock wave/turbulent boundary layer interaction at incipient separation was investigated in order to get insight into turbulence generation and amplification mechanisms in such flow fields. The flow along a two-dimensional 11.5° compression corner was studied experimentally at a Mach number of M=2.53 and with a momentum-thickness Reynolds number of Re_{θ }=5370 . From hot-wire boundary layer traverses and surface heat-flux density fluctuation measurements with the fast-response atomic layer thermopile, the turbulence structure and amplification was described. Space-time correlations of the mass-flux fluctuations across the boundary layer and the surface heat-flux density fluctuations were measured to further characterize the development of the turbulence structure across the interaction. The large-scale boundary layer structures are concealed by shock-related effects in the strongly disturbed shock-foot region. Shortly downstream, however, large-scale structures dominate the signal again, just as in the incoming flow. A mechanism explaining this behavior is suggested.

  11. First Signs of Flow Reversal Within a Separated Turbulent Boundary Layer

    NASA Astrophysics Data System (ADS)

    Hammerton, Jared; Lang, Amy

    2015-11-01

    A shark's skin is covered in millions of microscopic scales that have been shown to be able to bristle in a reversing flow. The motive of this project is to further explore a potential bio-inspired passive separation control mechanism which can reduce drag. To better understand this mechanism, a more complete understanding of flow reversal within the turbulent boundary layer is required. In order to capture this phenomenon, water tunnel testing at The University of Alabama was conducted. Using a long flat plate and a rotating cylinder, a large turbulent boundary layer and adverse pressure gradient were generated. Under our testing conditions the boundary layer had a Reynolds number of 200,000 and a boundary layer height in the testing window of 5.6 cm. The adverse pressure gradient causes the viscous length scale to increase and thus increase the size of the individual components of the turbulent boundary layer. This will make the low speed streaks approximately 1 cm in width and thus large enough to measure. Results will be presented that test our hypothesis that the first signs of flow reversal will occur within the section of lowest momentum located furthest from the wall, or within the low speed streaks. This Project was funded by NSF REU Site Award 1358991.

  12. Control of unsteady shock-induced turbulent boundary layer separation upstream of blunt fins

    NASA Technical Reports Server (NTRS)

    Kleifges, K.; Dolling, D. S.

    1993-01-01

    Fluctuating wall pressure measurements have been made on centerline upstream of blunt fins in a Mach 5 turbulent boundary layer. Standard time series analysis and conditional sampling algorithms have been used to examine the effects of leading edge sweepback, leading edge shape, and fin root modifications on the fluctuating pressures. Leading edge sweep considerably reduces the mean and rms pressure loading at the fin root, the extent of the region of unsteady separation shock motion, and the separation length. The frequency of pressure fluctuations in the intermittent region increases with leading edge sweepback, while the spectral content of pressure fluctuations in the separated region is virtually unchanged by leading edge sweep. A swept hemicylindrically blunted root fillet reduces the centerline upstream influence and intermittent region length by 50 percent, and reduces the mean and rms pressure loading at the fin root by about 75 percent and 95 percent respectively. Experiments using hemicylindrical, wedge shaped and flat leading edges show that while separated flow scales increase with increasing 'bluntness', intermittent region length and root loading decrease, and separation shock frequency increases.

  13. Ionic conductivity of the aqueous layer separating a lipid bilayer membrane and a glass support.

    PubMed

    White, Ryan J; Zhang, Bo; Daniel, Susan; Tang, John M; Ervin, Eric N; Cremer, Paul S; White, Henry S

    2006-12-01

    The in-plane ionic conductivity of the approximately 1-nm-thick aqueous layer separating a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer membrane and a glass support was investigated. The aqueous layer conductivity was measured by tip-dip deposition of a POPC bilayer onto the surface of a 20- to 75-microm-thick glass membrane containing a single conical-shaped nanopore and recording the current-voltage (i-V) behavior of the glass membrane nanopore/POPC bilayer structure. The steady-state current across the glass membrane passes through the nanopore (45-480 nm radius) and spreads radially outward within the aqueous layer between the glass support and bilayer. This aqueous layer corresponds to the dominant resistance of the glass membrane nanopore/POPC bilayer structure. Fluorescence recovery after photobleaching measurements using dye-labeled lipids verified that the POPC bilayer maintains a significant degree of fluidity on the glass membrane. The slopes of ohmic i-V curves yield an aqueous layer conductivity of (3 +/- 1) x 10(-3) Omega(-1) cm(-1) assuming a layer thickness of 1.0 nm. This conductivity is essentially independent of the concentration of KCl in the bulk solution (10-4 to 1 M) in contact with the membrane. The results indicate that the concentration and mobility of charge carriers in the aqueous layer between the glass support and bilayer are largely determined by the local structure of the glass/water/bilayer interface. PMID:17129059

  14. Phase separation and atomic ordering in indium gallium nitride epitaxial layers

    NASA Astrophysics Data System (ADS)

    Rao, Manu

    Phase separation and atomic ordering were investigated in InGaN layers grown by metalorganic chemical vapor deposition on (0001) sapphire substrates. Transmission electron microscopy (TEM) of InGaN layers during their early stages of growth reveal 2-D quantum rings that form spontaneously. In thick layers at InN contents of 3%, planview TEM images show a random distribution of atomic species and selected area diffraction (SAD) patterns do not exhibit satellite spots continuous to Bragg reflections. InN contents of 12% result in a speckled microstructure and satellites are present in SAD patterns. No satellites are observed along the [0001] direction, implying that phase separation is two-dimensional in nature and may occur on the surface while the layer is growing. These results are indicative of composition modulations lying in the (0001) growth plane. Samples containing InN fractions of between 22 and 34% exhibit microstructures having stronger contrast variations and SAD patterns with satellites further spaced from fundamental reflections. In cross-sectional TEM images, contrast striations oriented along [0001] are present except near the InGaN/GaN interface. The spacing of these striations is comparable to the composition modulation wavelengths calculated from SADPs and decreases with increasing InN content. Similarly, plan view TEM images taken from very thin specimens exhibit a domain structure with well aligned stripes within the domains. Increasing the growth rate from 400nm/h to 900nm/h results in a reduction in the intensity of satellite spots, indicating that the amplitude of composition modulations is reduced. The absence of contrast near the InGaN/GaN interface suggest reduced In incorporation, resulting in the absence of phase separation. Reduced In incorporation is confirmed by high angle angular dark field (HAADF) imaging and energy dispersive x-ray spectroscopy (EDS). X-ray diffraction and photoluminescence data are consistent with the occurrence

  15. DNS of self-similar adverse pressure gradient turbulent boundary layer at incipient separation

    NASA Astrophysics Data System (ADS)

    Soria, Julio; Kitsios, Vassili; Atkinson, Callum; Sillero, Juan; Borrell, Guillem; Gungar, Ayse; Jimenez, Javier

    2015-11-01

    A direct numerical simulation of a self-similar adverse pressure gradient turbulent boundary layer (APG-TBL) flow at incipient separation has been carried out. The maximum Reynolds number based on the momentum thickness, Reδ2 , reached in this DNS is 6,500. A wall-normal far-field boundary condition to effect the desired APG that will lead to the desired self-similar flow at the verge of separation has been developed. The self-similar analysis of the mean turbulent boundary layer equations yields the necessary conditions for a self-similar mean flow to exists. These conditions are tested using the DNS APG-TBL data base. First and second order statistics of the velocity across the APG-TBL are also presented in the light of the self-similar analysis results and compared to the results of a zero pressure gradient turbulent boundary layer DNS with similar mean inflow characteristics as the APG-TBL. The support of the ARC, NCI and Pawsey SCC funded by the Australian and Western Australian governments as well as the support of PRACE funded by the European Union are gratefully acknowledged.

  16. Flexible single-layer ionic organic-inorganic frameworks towards precise nano-size separation.

    PubMed

    Yue, Liang; Wang, Shan; Zhou, Ding; Zhang, Hao; Li, Bao; Wu, Lixin

    2016-01-01

    Consecutive two-dimensional frameworks comprised of molecular or cluster building blocks in large area represent ideal candidates for membranes sieving molecules and nano-objects, but challenges still remain in methodology and practical preparation. Here we exploit a new strategy to build soft single-layer ionic organic-inorganic frameworks via electrostatic interaction without preferential binding direction in water. Upon consideration of steric effect and additional interaction, polyanionic clusters as connection nodes and cationic pseudorotaxanes acting as bridging monomers connect with each other to form a single-layer ionic self-assembled framework with 1.4 nm layer thickness. Such soft supramolecular polymer frameworks possess uniform and adjustable ortho-tetragonal nanoporous structure in pore size of 3.4-4.1 nm and exhibit greatly convenient solution processability. The stable membranes maintaining uniform porous structure demonstrate precisely size-selective separation of semiconductor quantum dots within 0.1 nm of accuracy and may hold promise for practical applications in selective transport, molecular separation and dialysis systems. PMID:26923611

  17. Flexible single-layer ionic organic–inorganic frameworks towards precise nano-size separation

    PubMed Central

    Yue, Liang; Wang, Shan; Zhou, Ding; Zhang, Hao; Li, Bao; Wu, Lixin

    2016-01-01

    Consecutive two-dimensional frameworks comprised of molecular or cluster building blocks in large area represent ideal candidates for membranes sieving molecules and nano-objects, but challenges still remain in methodology and practical preparation. Here we exploit a new strategy to build soft single-layer ionic organic–inorganic frameworks via electrostatic interaction without preferential binding direction in water. Upon consideration of steric effect and additional interaction, polyanionic clusters as connection nodes and cationic pseudorotaxanes acting as bridging monomers connect with each other to form a single-layer ionic self-assembled framework with 1.4 nm layer thickness. Such soft supramolecular polymer frameworks possess uniform and adjustable ortho-tetragonal nanoporous structure in pore size of 3.4–4.1 nm and exhibit greatly convenient solution processability. The stable membranes maintaining uniform porous structure demonstrate precisely size-selective separation of semiconductor quantum dots within 0.1 nm of accuracy and may hold promise for practical applications in selective transport, molecular separation and dialysis systems. PMID:26923611

  18. LS Channel Estimation and Signal Separation for UHF RFID Tag Collision Recovery on the Physical Layer.

    PubMed

    Duan, Hanjun; Wu, Haifeng; Zeng, Yu; Chen, Yuebin

    2016-01-01

    In a passive ultra-high frequency (UHF) radio-frequency identification (RFID) system, tag collision is generally resolved on a medium access control (MAC) layer. However, some of collided tag signals could be recovered on a physical (PHY) layer and, thus, enhance the identification efficiency of the RFID system. For the recovery on the PHY layer, channel estimation is a critical issue. Good channel estimation will help to recover the collided signals. Existing channel estimates work well for two collided tags. When the number of collided tags is beyond two, however, the existing estimates have more estimation errors. In this paper, we propose a novel channel estimate for the UHF RFID system. It adopts an orthogonal matrix based on the information of preambles which is known for a reader and applies a minimum-mean-square-error (MMSE) criterion to estimate channels. From the estimated channel, we could accurately separate the collided signals and recover them. By means of numerical results, we show that the proposed estimate has lower estimation errors and higher separation efficiency than the existing estimates. PMID:27023560

  19. Flexible single-layer ionic organic-inorganic frameworks towards precise nano-size separation

    NASA Astrophysics Data System (ADS)

    Yue, Liang; Wang, Shan; Zhou, Ding; Zhang, Hao; Li, Bao; Wu, Lixin

    2016-02-01

    Consecutive two-dimensional frameworks comprised of molecular or cluster building blocks in large area represent ideal candidates for membranes sieving molecules and nano-objects, but challenges still remain in methodology and practical preparation. Here we exploit a new strategy to build soft single-layer ionic organic-inorganic frameworks via electrostatic interaction without preferential binding direction in water. Upon consideration of steric effect and additional interaction, polyanionic clusters as connection nodes and cationic pseudorotaxanes acting as bridging monomers connect with each other to form a single-layer ionic self-assembled framework with 1.4 nm layer thickness. Such soft supramolecular polymer frameworks possess uniform and adjustable ortho-tetragonal nanoporous structure in pore size of 3.4-4.1 nm and exhibit greatly convenient solution processability. The stable membranes maintaining uniform porous structure demonstrate precisely size-selective separation of semiconductor quantum dots within 0.1 nm of accuracy and may hold promise for practical applications in selective transport, molecular separation and dialysis systems.

  20. LS Channel Estimation and Signal Separation for UHF RFID Tag Collision Recovery on the Physical Layer

    PubMed Central

    Duan, Hanjun; Wu, Haifeng; Zeng, Yu; Chen, Yuebin

    2016-01-01

    In a passive ultra-high frequency (UHF) radio-frequency identification (RFID) system, tag collision is generally resolved on a medium access control (MAC) layer. However, some of collided tag signals could be recovered on a physical (PHY) layer and, thus, enhance the identification efficiency of the RFID system. For the recovery on the PHY layer, channel estimation is a critical issue. Good channel estimation will help to recover the collided signals. Existing channel estimates work well for two collided tags. When the number of collided tags is beyond two, however, the existing estimates have more estimation errors. In this paper, we propose a novel channel estimate for the UHF RFID system. It adopts an orthogonal matrix based on the information of preambles which is known for a reader and applies a minimum-mean-square-error (MMSE) criterion to estimate channels. From the estimated channel, we could accurately separate the collided signals and recover them. By means of numerical results, we show that the proposed estimate has lower estimation errors and higher separation efficiency than the existing estimates. PMID:27023560

  1. Micro vortex generator control of axisymmetric high-speed laminar boundary layer separation

    NASA Astrophysics Data System (ADS)

    Estruch-Samper, D.; Vanstone, L.; Hillier, R.; Ganapathisubramani, B.

    2015-09-01

    Interest in the development of micro vortex generators (MVGs) to control high-speed flow separation has grown in the last decade. In contrast to conventional vortex generators, MVGs are fully submerged in the boundary layer and have the potential of inducing surface flow mixing with marginal drag penalty when suitably designed. Also, they do not result in undesired reduced mass flow such as with suction methods. The flow mechanisms at the location of MVGs are not yet fully understood, and optimal designs are difficult to establish given that both numerical predictions and experiments are particularly challenged for short element heights, yet optimal MVGs are generally expected to be at least shorter than half the local boundary layer thickness. The present work aims at investigating experimentally the fundamental flow physics concerning an individual MVG element (of `canonical' or simplified geometry) at a range of near-wall heights. A fully laminar base flow is considered so as to isolate the effect of incoming turbulence as well as the more complex physics that may occur when specific and/or multiple elements are used. Tests were performed in a gun tunnel at a freestream Mach number of 8.9 and Reynolds number of /m, and the basic test model consisted of a blunt-nosed cylinder which produced an axisymmetric laminar boundary layer with an edge Mach number of 3.4 and Reynolds number of /m at the MVG location. A laminar shock-wave/boundary layer interaction with separation was induced by a flare located further downstream on the model. Measurements consisted of time-resolved surface heat transfer obtained in the axial direction immediately downstream of the MVG and along the interaction, together with simultaneous high-speed schlieren imaging. The height () of the MVG element used in a `diamond' configuration (square planform with one vertex facing the flow) was adjusted between tests ranging from = 0.03 to 0.58, where the local undisturbed boundary layer thickness

  2. Study of Separation and Transition of Boundary Layer For Flow Through Linear Turbine Cascade

    NASA Astrophysics Data System (ADS)

    Mutnuri, Pavan Kumar; Ayyalasomayajula, Haritha; Ghia, Urmila; "Karman" Ghia, Kirti

    2002-11-01

    The objective of the present work is to study the boundary-layer separation of unsteady flow in turbomachines. A parallel, Chimera version of FDL3DI is used as the flow solver. The code uses second and fourth-order damping for a stable numerical solution. The use of fourth-order damping terms necessitates a minimum of 4-cell overlap at inter-block boundaries. The extended overlap is also necessary for the later intended use of a higher-order accurate differencing technique. The blocks are extended in such a way that the grid points in the overlap region coincide with the grid points in the neighboring-block (under-lapping) region and hence direct injection may be used for inter-block communication. This maintains the order of accuracy of the difference scheme; otherwise, any interpolation involved in inter-block communication needs to be of the same high-order accuracy as the difference scheme of the flow equations. PEGASUS is used to update the flow variables at the block interfaces. A 12-block structured grid of multiple topologies generated by GRIDPRO is used. Low-Re separated flow results are examined and will be presented for a cascade configuration. Passive control methodology is also planned for application to unsteady boundary-layer flow separation in the cascade.

  3. Large-eddy simulation of separation-reattachment of a flat-plate turbulent boundary layer

    NASA Astrophysics Data System (ADS)

    Cheng, Wan; Pullin, Dale; Samtaney, Ravi

    2014-11-01

    We describe large-eddy simulations (LES) of turbulent boundary-layer flow over a flat plate at high Reynolds number in the presence of three-dimensional flow separation. The stretched-vortex subgrid-scale model is used in the bulk of the flow domain combined with a wall-model that is a two-dimensional extension of that described by Chung and Pullin [J. Fluid Mech. 631, 281 (2009)]. Wall-normal averaging of the wall-parallel, stream-wise momentum equations combined with local inner scaling for the resolved-scale velocity gives an ordinary differential equation describing the wall shear-stress vector at each wall point. Together with a specification of a slip velocity at a raised, wall-parallel plane, this provides a boundary condition for the outer LES that allows local backflow. The present LES is motivated by experiments on flows exhibiting separation induced by the response of a turbulent boundary layer to an adverse-favorable pressure-gradient profile. Detailed discussion of detachment and reattachment of the separation bubble will be presented.

  4. Structure of the Supersonic Turbulent Boundary Layer and its Influence on Unsteady Separation.

    NASA Astrophysics Data System (ADS)

    Unalmis, Omer Haldun

    1995-01-01

    This experimental study evolved out of earlier work by other investigators which focused on the unsteadiness of shock-wave induced turbulent boundary layer separation. The primary objective of the current study was to gain a better understanding of the structure and behavior of the compressible turbulent boundary layer, in order to (i) learn more about the large-scale turbulent structures which the earlier work showed were responsible for the high frequency, "jitter" motion of the separated flow, and (ii) determine what in the incoming boundary layer is the cause of the "low frequency component" which appears to be responsible for the low frequency pulsation of the separated flow. Results from fluctuating wall pressure measurements show that the overall streamwise decay length of the turbulent structure is about 20 delta_0, where delta_0 is the boundary layer thickness. The spanwise decay length is about 3 delta_0. Experiments with and without vortex generators showed that the decay of the low frequency component of the wall pressure field appears to be closely connected to Gortler vortices in the tunnel floor boundary layer. With respect to the decay of the high frequency component, the Strouhal number was shown to be an appropriate correlating parameter for incompressible, subsonic, and supersonic boundary layers. Bull's suggestion that the structures lose their coherence over distances of about four wavelengths appears to be approximately valid at Mach 5. Comparisons of wall pressure spectra were made under incompressible, subsonic, and supersonic flow conditions. The subsonic data included flight-test results from The Boeing Company. "Mixed" scaling does the best job of collapsing the compressible and incompressible data. The flight-test spectra, however, did not collapse with the wind tunnel data and it was shown that this was mainly due to the lack of well-controlled conditions in the flight-test environment. Of the two methods widely used for predicting the

  5. Pointwise and scanning laser anemometer measurements in steady and unsteady separated turbulent boundary layers

    NASA Technical Reports Server (NTRS)

    Simpson, R. L.; Chehroudi, B.; Shivaprasad, B. G.

    1982-01-01

    The physical features of steady and unsteady freestream separating turbulent boundary layers that have been determined by pointwise laser anemometer measurements are outlined. It is seen that the large-scale structures control the outer region's backflow behavior. Near the wall, the mean backflow velocity profile for both the steady and unsteady cases is found to scale on the maximum negative mean velocity and its distance from the wall. A description is given of a scanning laser anemometer that produces nearly instantaneous velocity profiles for examing the temporal features of these large-scale structures. Also described is a 'zero-wake' seeder that supplies particles to the outer shear layer and freestream flow with a minimal disturbance.

  6. Separation of catechins and O-methylated (-)-epigallocatechin gallate using polyamide thin-layer chromatography.

    PubMed

    Wang, Kunbo; Chen, Qincao; Lin, Yong; Yu, Shuangshang; Lin, Haiyan; Huang, Jianan; Liu, Zhonghua

    2016-04-01

    Thin-layer chromatography (TLC) method for the separation and quantitative determination of seven related compounds: (+)-catechin (C), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG), (-)-epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3″Me) and (-)-epigallocatechin- 3-O-(4-O-methyl) gallate (EGCG4″Me) has been developed. The above-mentioned seven compounds have been resolved using polyamide TLC plates using a double-development with methanol followed by acetone/acetic acid (2:1, v/v). In addition, separation of the phenolic acids namely gallic acid, chlorogenic acid, and caffeic acid was achieved using the same solvent system. The applicability of the method was checked by screening of extracts of green, black, oolong, white tea and tea cultivars leaves. PMID:26990737

  7. MEMS flexible thermal flow sensor for measurement of boundary layer separation

    NASA Astrophysics Data System (ADS)

    Yu, Jui-Ming; Leu, Tzong-Shyng; Miau, Jiun-Jih; Chen, Shih-Jiun

    2016-05-01

    Micro-electro-mechanical systems (MEMS) thermal flow sensors featured with high spatial resolutions, fast frequency response and minimal interference with fluid flow have been applied widely in boundary-layer studies and aerodynamic flow sensing and control due to the inherent outstanding performances. In this study, MEMS thermal flow sensors were designed and fabricated on a flexible skin using the MEMS technology. The dimension of a single sensing element was 200 μm × 260 μm, which had a resistance of about 200 Ω after annealing. By configuring thermal flow sensors in either a single thermal flow sensor and a thermal tuft sensor, separation points of a two-dimensional (2D) LS(1) 0417 airfoil at various angles of attack could be precisely detected. The experimental results show good agreement with the hot wire sensor and particle traced flow visualization in detecting the separation point on the suction surface of the airfoil.

  8. The separation of grain and grain boundary impedance in thin yttria stabilized zirconia (YSZ) layers

    PubMed Central

    Gerstl, M.; Navickas, E.; Friedbacher, G.; Kubel, F.; Ahrens, M.; Fleig, J.

    2011-01-01

    An improved electrode geometry is proposed to study thin ion conducting films by impedance spectroscopy. It is shown that long, thin, and closely spaced electrodes arranged interdigitally allow a separation of grain and grain boundary effects also in very thin films. This separation is shown to be successful for yttria stabilized zirconia (YSZ) layers thinner than 20 nm. In a series of experiments it is demonstrated that the extracted parameters correspond to the YSZ grain boundary and grain bulk resistances or to grain boundary and substrate capacitances. Results also show that our YSZ films produced by pulsed-laser deposition (PLD) on sapphire substrates exhibit a bulk conductivity which is very close to that of macroscopic YSZ samples.

  9. Study of the Pressure Rise Across Shock Waves Required to Separate Laminar and Turbulent Boundary Layers

    NASA Technical Reports Server (NTRS)

    Donaldson, Coleman Dup; Lange, Roy H

    1952-01-01

    Results are presented of a dimensional study and an experimental investigation of the pressure rise across a shock wave which causes separation of the boundary layer on a flat plate. The experimental part of the investigation was conducted at a Mach number of 3.03 for a Reynolds number range of 2 x 10 (sup) 6 to 19 x 10 (sup) 6. The available experimental data are compared with the predictions of the present study, and the significance of the results obtained is discussed relative to certain practical design problems.

  10. Bacterial surface layer proteins as a novel capillary coating material for capillary electrophoretic separations.

    PubMed

    Moreno-Gordaliza, Estefanía; Stigter, Edwin C A; Lindenburg, Petrus W; Hankemeier, Thomas

    2016-06-01

    A novel concept for stable coating in capillary electrophoresis, based on recrystallization of surface layer proteins on hydrophobized fused silica capillaries, was demonstrated. Surface layer protein A (SlpA) from Lactobacillus acidophilus bacteria was extracted, purified and used for coating pre-silanized glass substrates presenting different surface wettabilities (either hydrophobic or hydrophilic). Contact angle determination on SlpA-coated hydrophobic silica slides showed that the surfaces turned to hydrophilic after coating (53 ± 5°), due to a protein monolayer formation by protein-surface hydrophobic interactions. Visualization by atomic force microscopy demonstrated the presence of a SlpA layer on methylated silica slides displaying a surface roughness of 0.44 ± 0.02 nm. Additionally, a protein layer was visualized by fluorescence microscopy in methylated silica capillaries coated with SlpA and fluorescein isothiocyanate-labeled. The SlpA-coating showed an outstanding stability, even after treatment with 20 mM NaOH (pH 12.3). The electroosmotic flow in coated capillaries showed a partial suppression at pH 7.50 (3.8 ± 0.5 10(-9) m(2) V(-1) s(-1)) when compared with unmodified fused silica (5.9 ± 0.1 10(-8) m(2) V(-1) s(-1)). To demonstrate the potential of this novel coating, the SlpA-coated capillaries were applied for the first time for electrophoretic separation, and proved to be very suitable for the isotachophoretic separation of lipoproteins in human serum. The separations showed a high degree of repeatability (absolute migration times with 1.1-1.8% coefficient-of-variation (CV) within a day) and 2-3% CV inter-capillary reproducibility. The capillaries were stable for more than 100 runs at pH 9.40, and showed to be an exceptional alternative for challenging electrophoretic separations at long-term use. PMID:27155306

  11. Finite-difference simulation of transonic separated flow using a full potential boundary layer interaction approach

    NASA Technical Reports Server (NTRS)

    Van Dalsem, W. R.; Steger, J. L.

    1983-01-01

    A new, fast, direct-inverse, finite-difference boundary-layer code has been developed and coupled with a full-potential transonic airfoil analysis code via new inviscid-viscous interaction algorithms. The resulting code has been used to calculate transonic separated flows. The results are in good agreement with Navier-Stokes calculations and experimental data. Solutions are obtained in considerably less computer time than Navier-Stokes solutions of equal resolution. Because efficient inviscid and viscous algorithms are used, it is expected this code will also compare favorably with other codes of its type as they become available.

  12. In-line thermoelectric module

    DOEpatents

    Pento, Robert; Marks, James E.; Staffanson, Clifford D.

    2000-01-01

    A thermoelectric module with a plurality of electricity generating units each having a first end and a second end, the units being arranged first end to second end along an in-line axis. Each unit includes first and second elements each made of a thermoelectric material, an electrically conductive hot member arranged to heat one side of the first element, and an electrically conductive cold member arranged to cool another side of the first element and to cool one side of the second element. The hot member, the first element, the cold member and the second element are supported in a fixture, are electrically connected respectively to provide an electricity generating unit, and are arranged respectively in positions along the in-line axis. The individual components of each generating unit and the respective generating units are clamped in their in-line positions by a loading bolt at one end of the fixture and a stop wall at the other end of the fixture. The hot members may have a T-shape and the cold members an hourglass shape to facilitate heat transfer. The direction of heat transfer through the hot members may be perpendicular to the direction of heat transfer through the cold members, and both of these heat transfer directions may be perpendicular to the direction of current flow through the module.

  13. Thin-layer chromatographic (TLC) separations and bioassays of plant extracts to identify antimicrobial compounds.

    PubMed

    Kagan, Isabelle A; Flythe, Michael D

    2014-01-01

    A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the chromatograms to microbial suspensions (e.g. fungi or bacteria in broth or agar), allowing time for the microbes to grow in a humid environment, and visualizing zones with no microbial growth. The effectiveness of this screening method, known as bioautography, depends on both the quality of the chromatographic separation and the care taken with microbial culture conditions. This paper describes standard protocols for TLC and contact bioautography with a novel application to amino acid-fermenting bacteria. The extract is separated on flexible (aluminum-backed) silica TLC plates, and bands are visualized under ultraviolet (UV) light. Zones are cut out and incubated face down onto agar inoculated with the test microorganism. Inhibitory bands are visualized by staining the agar plates with tetrazolium red. The method is applied to the separation of red clover (Trifolium pratense cv. Kenland) phenolic compounds and their screening for activity against Clostridium sticklandii, a hyper ammonia-producing bacterium (HAB) that is native to the bovine rumen. The TLC methods apply to many types of plant extracts and other bacterial species (aerobic or anaerobic), as well as fungi, can be used as test organisms if culture conditions are modified to fit the growth requirements of the species. PMID:24747583

  14. Thin-layer Chromatographic (TLC) Separations and Bioassays of Plant Extracts to Identify Antimicrobial Compounds

    PubMed Central

    Kagan, Isabelle A.; Flythe, Michael D.

    2014-01-01

    A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the chromatograms to microbial suspensions (e.g. fungi or bacteria in broth or agar), allowing time for the microbes to grow in a humid environment, and visualizing zones with no microbial growth. The effectiveness of this screening method, known as bioautography, depends on both the quality of the chromatographic separation and the care taken with microbial culture conditions. This paper describes standard protocols for TLC and contact bioautography with a novel application to amino acid-fermenting bacteria. The extract is separated on flexible (aluminum-backed) silica TLC plates, and bands are visualized under ultraviolet (UV) light. Zones are cut out and incubated face down onto agar inoculated with the test microorganism. Inhibitory bands are visualized by staining the agar plates with tetrazolium red. The method is applied to the separation of red clover (Trifolium pratense cv. Kenland) phenolic compounds and their screening for activity against Clostridium sticklandii, a hyper ammonia-producing bacterium (HAB) that is native to the bovine rumen. The TLC methods apply to many types of plant extracts and other bacterial species (aerobic or anaerobic), as well as fungi, can be used as test organisms if culture conditions are modified to fit the growth requirements of the species. PMID:24747583

  15. Turbulent boundary layer separation over a rearward facing ramp and its control through mechanical excitation

    NASA Technical Reports Server (NTRS)

    Mckinzie, Daniel J., Jr.

    1991-01-01

    A vane oscillating about a fixed point at the inlet to a two-dimensional 20 degree rearward facing ramp has proven effective in delaying the separation of a turbulent boundary layer. Measurements of the ramp surface static pressure coefficient obtained under the condition of vane oscillation and constant inlet velocity revealed that two different effects occurred with surface distance along the ramp. In the vicinity of the oscillating vane, the pressure coefficients varied as a negative function of the vane's trailing edge rms velocity; the independent variable on which the rms velocity depends are the vane's oscillation frequency and its displacement amplitude. From a point downstream of the vane to the exit of the ramp; however, the pressure coefficient varied as a more complex function of the two independent variables. That is, it was found to vary as a function of the vane's oscillation frequency throughout the entire range of frequencies covered during the test, but over only a limited range of the trailing edge displacement amplitudes covered. More specifically, the value of the pressure coefficient was independent of increases in the vane's displacement amplitude above approximately 35 inner wall units of the boundary layer. Below this specific amplitude it varied as a function of the vane's trailing edge rms velocity. This height is close to the upper limit of the buffer layer. A parametric study was made to determine the variation of the maximum static pressure recovery as a function of the vane's oscillation frequency, for several ramp inlet velocities and a constant displacement amplitude of the vane's trailing edge. The results indicate that the phenomenon producing the optimum delay of separation may be Strouhal number dependent. Corona anemometer measurements obtained in the inner wall regions of the boundary layer for the excited case reveal a large range of unsteadiness in the local velocities. These measurements imply the existence of inflections

  16. The effects of laser plasma discharge on a separating boundary layer

    NASA Astrophysics Data System (ADS)

    Browne, Kevin Patrick

    Modification of the separation and drag characteristics of a laminar airfoil using a remotely located high-power laser was experimentally investigated in a low speed, low-turbulence wind tunnel. It was proposed that pulsed laser energy could be used to cause a disturbance in the boundary layer of a laminar airfoil thus modifying the flow by inducing a cross exchange of momentum within the boundary layer. The result is a unique zero net mass flux and zero net momentum flux actuator for delaying separation. A 500 mm chord length laminar airfoil was designed and fabricated to closely emulate in the wind tunnel the flight characteristics of a Cessna 177 at cruise speed. At zero degrees angle of attack the airfoil was determined to have an incipient laminar separation bubble on its lifting surface between 67 and 80% chord. By focusing the collimated laser beam emitted from a 900mW Q-switched YAG laser a strong plasma pulse was generated from the optical breakdown of the air. The plasma was focused to a location approximately 2 mm in front of the airfoil. High temperature plasma produced by each pulse generates a shockwave and volume of heated turbulent air which interacts with the airfoil and travels along its lifting surface. Particle Image Velocimetry (PIV) system was used as the primary data collection method. Determining the effects of the plasma on the flow over the airfoil requires measuring the behavior deep within the boundary layer which is typically less than 2 mm thick. Custom optics were used to capture flow behavior in a 6 mm x 6 mm field of view along the centerline of the airfoil. The PIV system was electronically triggered by the plasma laser. By varying the trigger delay time a range of data captured the onset, peak and decay of the plasma with fine spatial resolution. Results of this investigation show that a burst of turbulence generated by the pulsed plasma exchanges significant momentum between the freestream and the incipient separation bubble

  17. Boundary layer and separation control on wings at low Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Yang, Shanling

    Results on boundary layer and separation control through acoustic excitation at low Re numbers are reported. The Eppler 387 profile is specifically chosen because of its pre-stall hysteresis and bi-stable state behavior in the transitional Re regime, which is a result of flow separation and reattachment. External acoustic forcing on the wing yields large improvements (more than 70%) in lift-to-drag ratio and flow reattachment at forcing frequencies that correlate with the measured anti-resonances in the wind tunnel. The optimum St/Re1/2 range for Re = 60,000 matches the proposed optimum range in the literature, but there is less agreement for Re = 40,000, which suggests that correct St scaling has not been determined. The correlation of aerodynamic improvements to wind tunnel resonances implies that external acoustic forcing is facility-dependent, which inhibits practical application. Therefore, internal acoustic excitation for the same wing profile is also pursued. Internal acoustic forcing is designed to be accomplished by embedding small speakers inside a custom-designed wing that contains many internal cavities and small holes in the suction surface. However, initial testing of this semi-porous wing model shows that the presence of the small holes in the suction surface completely transforms the aerodynamic performance by changing the mean chordwise separation location and causing an originally separated, low-lift state flow to reattach into a high-lift state. The aerodynamic improvements are not caused by the geometry of the small holes themselves, but rather by Helmholtz resonance that occurs in the cavities, which generate tones that closely match the intrinsic flow instabilities. Essentially, opening and closing holes in the suction surface of a wing, perhaps by digital control, can be used as a means of passive separation control. Given the similarity of wing-embedded pressure tap systems to Helmholtz resonators, particular attention must be given to the

  18. Using the in-line component for fixed-wing EM 1D inversion

    NASA Astrophysics Data System (ADS)

    Smiarowski, Adam

    2015-09-01

    Numerous authors have discussed the utility of multicomponent measurements. Generally speaking, for a vertical-oriented dipole source, the measured vertical component couples to horizontal planar bodies while the horizontal in-line component couples best to vertical planar targets. For layered-earth cases, helicopter EM systems have little or no in-line component response and as a result much of the in-line signal is due to receiver coil rotation and appears as noise. In contrast to this, the in-line component of a fixed-wing airborne electromagnetic (AEM) system with large transmitter-receiver offset can be substantial, exceeding the vertical component in conductive areas. This paper compares the in-line and vertical response of a fixed-wing airborne electromagnetic (AEM) system using a half-space model and calculates sensitivity functions. The a posteriori inversion model parameter uncertainty matrix is calculated for a bathymetry model (conductive layer over more resistive half-space) for two inversion cases; use of vertical component alone is compared to joint inversion of vertical and in-line components. The joint inversion is able to better resolve model parameters. An example is then provided using field data from a bathymetry survey to compare the joint inversion to vertical component only inversion. For each inversion set, the difference between the inverted water depth and ship-measured bathymetry is calculated. The result is in general agreement with that expected from the a posteriori inversion model parameter uncertainty calculation.

  19. Mixing layer dynamics in separated flow over an estuarine sill with variable stratification

    NASA Astrophysics Data System (ADS)

    Talke, S. A.; Horner-Devine, A. R.; Chickadel, C. C.

    2010-09-01

    We investigate the generation of a mixing layer in the separated flow behind an estuarine sill (height H ˜ 4 m) in the Snohomish River, Washington as part of a larger investigation of coherent structures using remote and in situ sensing. During increasing ebb flows the depth d and stratification decrease and a region of sheared flow characterized by elevated production of turbulent kinetic energy develops. Profiles of velocity and acoustic backscatter exhibit coherent fluctuations of order 0.1 Hz and are used to define the boundaries of the mixing layer. Variations in the mixing layer width and its embedded coherent structures are caused by changes to both the normalized sill height H/d and to a bulk Richardson number Rih defined using the depth of flow over the sill. Entrainment ET and the mixing layer expansion angle increase as stratification and the bulk Richardson number decrease; this relationship is parameterized as ET = 0.07Rih-0.5 and is valid for approximately 0.1 < Rih < 2.8. Available comparisons with literature for inertially dominated conditions (Rih < 0.1) are consistent with our data and validate our approach, though lateral gradients may introduce an upwards bias of approximately 20%. As the ratio H/d increases over the ebb, the free surface boundary pushes the mixing layer trajectory downward, reduces its expansion angle, and produces asymmetry in the acoustic backscatter (coherent structures). Three-dimensional divergence, as imaged by infrared video and transecting data, becomes more prominent for H/d > 0.8 due to blocking of flow by the sill.

  20. Layer-by-Layer Deposition of Organic-Inorganic Hybrid Multilayer on Microporous Polyethylene Separator to Enhance the Electrochemical Performance of Lithium-Ion Battery.

    PubMed

    Xu, Wuxia; Wang, Zhuyi; Shi, Liyi; Ma, Ying; Yuan, Shuai; Sun, Lining; Zhao, Yin; Zhang, Meihong; Zhu, Jiefang

    2015-09-23

    A simple layer-by-layer (LbL) self-assembly process of poly(acrylic acid) (PAA) and ZrO2 was applied to construct functional ultrathin multilayers on polyethylene (PE) separators without sacrificing the excellent porous structure of separators. Such PAA/ZrO2 LbL-modified PE separators possess good electrolyte wettability, excellent electrolyte uptake, high ionic conductivity and large Li(+) transference number. More importantly, the top layer of LbL self-assembly would affect the dissociation of electrolyte and the formation of solid electrolyte interphase (SEI) layer in half-cells. Compared with the pristine and (PAA/ZrO2)1PAA-modified PE separators, (PAA/ZrO2)3-modified PE separator shows a larger Li(+) transference number (0.6) and a faster tendency to form a stable SEI layer, endowing half-cells with excellent capacity retention at high C-rates and superior cycling performance. These fascinating characteristics will provide the LbL self-assembly with a promising method to improve the surface property of PE separators for high performance lithium-ion batteries. PMID:26336109

  1. A new turbulence closure model for boundary layer flows with strong adverse pressure gradients and separation

    NASA Technical Reports Server (NTRS)

    Johnson, D. A.; King, L. S.

    1984-01-01

    A new turbulence closure model designed specifically to treat two-dimensional, turbulent boundary layers with strong adverse pressure gradients and attendant separation, is presented. The influence of history effects are modeled by using an ordinary differential equation (ODE) derived from the turbulence kinetic-energy equation, to describe the streamwise development of the maximum Reynolds shear stress in conjunction with an assumed eddy-viscosity distribution which has as its velocity scale the maximum Reynolds shear stress. In the outer part of the boundary layer, the eddy viscosity is treated as a free parameter which is adjusted in order to satisfy the ODE for the maximum shear stress. Because of this, the model s not simply an eddy-viscosity model, but contains features of a Reynolds-stress model. Comparisons with experiments are presented which clearly show the proposed model to be superior to the Cebeci-Smith model in treating strongly retarded and separated flows. In contrast to two-equation, eddy-viscosity models, it requires only slightly more computational effort than simple models like the Cebeci-Smith model.

  2. An INDEHISCENT-Controlled Auxin Response Specifies the Separation Layer in Early Arabidopsis Fruit.

    PubMed

    van Gelderen, Kasper; van Rongen, Martin; Liu, An'an; Otten, Anne; Offringa, Remko

    2016-06-01

    Seed dispersal is an important moment in the life cycle of a plant species. In Arabidopsis thaliana, it is dependent on transcription factor INDEHISCENT (IND)-mediated specification of a separation layer in the dehiscence zone found in the margin between the valves (carpel walls) and the central replum of the developing fruit. It was proposed that IND specifies the separation layer by inducing a local auxin minimum at late stages of fruit development. Here we show that morphological differences between the ind mutant and wild-type fruit already arise at early stages of fruit development, coinciding with strong IND expression in the valve margin. We show that IND-reduced PIN-FORMED3 (PIN3) auxin efflux carrier abundance leads to an increased auxin response in the valve margin during early fruit development, and that the concomitant cell divisions that form the dehiscence zone are lacking in ind mutant fruit. Moreover, IND promoter-driven ectopic expression of the AGC kinases PINOID (PID) and WAG2 induced indehiscence by expelling auxin from the valve margin at stages 14-16 of fruit development through increased PIN3 abundance. Our results show that IND, besides its role at late stages of Arabidopsis fruit development, functions at early stages to facilitate the auxin-triggered cell divisions that form the dehiscence zone. PMID:26995296

  3. Thermophoretic motion behavior of submicron particles in boundary-layer-separation flow around a droplet.

    PubMed

    Wang, Ao; Song, Qiang; Ji, Bingqiang; Yao, Qiang

    2015-12-01

    As a key mechanism of submicron particle capture in wet deposition and wet scrubbing processes, thermophoresis is influenced by the flow and temperature fields. Three-dimensional direct numerical simulations were conducted to quantify the characteristics of the flow and temperature fields around a droplet at three droplet Reynolds numbers (Re) that correspond to three typical boundary-layer-separation flows (steady axisymmetric, steady plane-symmetric, and unsteady plane-symmetric flows). The thermophoretic motion of submicron particles was simulated in these cases. Numerical results show that the motion of submicron particles around the droplet and the deposition distribution exhibit different characteristics under three typical flow forms. The motion patterns of particles are dependent on their initial positions in the upstream and flow forms. The patterns of particle motion and deposition are diversified as Re increases. The particle motion pattern, initial position of captured particles, and capture efficiency change periodically, especially during periodic vortex shedding. The key effects of flow forms on particle motion are the shape and stability of the wake behind the droplet. The drag force of fluid and the thermophoretic force in the wake contribute jointly to the deposition of submicron particles after the boundary-layer separation around a droplet. PMID:26764827

  4. Boundary-Layer Separation Regimes: An Analysis Based on Large-Eddy Simulations

    NASA Astrophysics Data System (ADS)

    Sachsperger, J.; Serafin, S.; Grubisic, V.

    2013-12-01

    Boundary layer separation (BLS) may occur when a strong adverse pressure gradient force is imposed on boundary layer flow. The strong deceleration caused by the pressure gradient results, through mass continuity, in the detachment of streamlines from the surface. In neutrally stratified flow, the boundary layer commonly separates at the salient edge of very sharp obstacles. In the case of stratified flow, pressure perturbations strong enough to cause BLS can also be induced by internal gravity waves. A well-known phenomenon related to wave-induced BLS is that of atmospheric rotors. Laboratory experiments in a stratified water tank show that the key governing parameters for BLS over a two-dimensional obstacle are the airflow speed U, the stratification N, the height H and half-width L of the mountain. These quantities can be combined to form the non-dimensional numbers NH/U (non-dimensional mountain height) and H/L (vertical aspect ratio), which can be used for a concise characterization of the flow regime. Wave-induced BLS was shown to occur preferentially for relatively high non-dimensional mountain height and for relatively low aspect ratio. Linear theory suggests similar results. The behavior of BLS in strongly nonlinear flow regimes and its response to variable surface friction is less known. In this study, the CM1 model is used to perform large eddy simulations (LES) under free-slip and quasi-no-slip lower boundary conditions. Conditions favorable for BLS are investigated under different combinations of NH/U, H/L and the surface momentum flux. Results confirm the importance of NH/U and H/L as key parameters in defining the flow regime in the free-slip case, and show the expected transition from subcritical to supercritical flow associated with wave breaking and downslope windstorms. Findings from quasi-no-slip simulations show that rotors downstream are able to induce secondary non-hydrostatic waves even if the flow over the mountain upstream is within the

  5. Discontinuous Inter-Granular Separations (DIGS) in the Gas Nitride Layer of ISS Race Rings

    NASA Technical Reports Server (NTRS)

    Figert, John; Dasgupta, Rajib; Martinez, James

    2010-01-01

    The starboard solar alpha rotary joint (SARJ) race ring on the International space station (ISS) failed due to severe spalling of the outer diameter, 45 degree (outer canted) nitrided surface. Subsequent analysis at NASA-KSC revealed that almost all of the debris generated due to the failure was nitrided 15-5 stainless steel. Subsequent analysis of the nitride control coupons (NCC) at NASA-JSC revealed the presence of discontinuous inter-granular separations (DIGS) in the gas nitride layer. These DIGS were present in the inter-granular networking located in the top 2 mils of the nitride layer. The manufacturer's specification requires the maximum white structure to be 0.0003 inches and intergranular networking below the allowable white structure depth to be cause for rejection; a requirement that the NCCs did not meet. Subsequent testing and analysis revealed that lower DIGS content significantly lowered the probability of nitride spalling in simulated, dry condition runs. One batch of nitride samples with DIGS content similar to the port SARJ (did not fail on orbit) which exhibited almost no nitride spalling after being run on one test rig. Another batch of nitride samples with DIGS content levels similar to the starboard SARJ exhibited significant nitride spalling on the same test rig with the same load under dry conditions. Although DIGS were not the root cause of starboard race ring failure, testing indicates that increased DIGS reduced the robustness of the gas nitride layer under dry operating conditions.

  6. Hot Microbubble Injection in Thin Liquid Film Layers for Ammonia-Water Separation

    NASA Astrophysics Data System (ADS)

    Desai, Pratik; Zimmerman, William

    2015-11-01

    140 MT of NH3 produced p.a. barely keeps up with the global usage of this ubiquitously used commodity. NH3 manufacture & later remediation from landfill leachate to lower eco-toxicity makes further demands on the energy utilised for this ``NH3 cycle.'' Moreover, current methods for lowering eco-toxicity destroy NH3 rather than recovering it. Air stripping is a widely employed low energy industrial process used for NH3 recovery but has a long processing time- ≅24h for 60% efficiency & 100h for 95% efficiency. The solution presented herein is based on hot microbubble injection in thin liquid film layers designed to separate NH3 from NH3-H2O solutions. The transport phenomena exhibited by the microbubbles helps them separate volatile liquids effectively with negligible sensible heat transfer. This process is nearly isothermal simply because evaporation by microbubbles is controlled by internal mixing, which is fast relative to sensible heat transfer, when limited to short contact times in thin films. A 1000-3000-fold increase in mass transfer, over conventional stripping, and a 100% separation efficiency achieved in a processing time of 30 minutes is observed, potentially, if persisting with industrial scale up, resulting in a 200-fold reduction in processing time. The authors would like to acknowledge contributions from Michael Turley MEng - University of Sheffield and Richard Robinson from Viridor for their help and support as well as EPSRC Grant Number EP/K001329/1 - ``4CU''.

  7. Ultrathin membranes of single-layered MoS2 nanosheets for high-permeance hydrogen separation

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Wang, Zhenggong; Wang, Lei; Hu, Liang; Jin, Jian

    2015-10-01

    Single-layered MoS2-based ultrathin membranes with well-controlled thicknesses are prepared by a simple filtration method, and for the first time applied to gas separation. These membranes exhibit superior H2/CO2 separation performance and extremely high H2 permeance. The H2/CO2 separation performance surpasses the state-of-the-art upper-bound of polymeric and inorganic membranes.Single-layered MoS2-based ultrathin membranes with well-controlled thicknesses are prepared by a simple filtration method, and for the first time applied to gas separation. These membranes exhibit superior H2/CO2 separation performance and extremely high H2 permeance. The H2/CO2 separation performance surpasses the state-of-the-art upper-bound of polymeric and inorganic membranes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06321c

  8. Three-dimensional boundary-layer instability and separation induced by small-amplitude streamwise vorticity in the upstream flow

    NASA Technical Reports Server (NTRS)

    Goldstein, M. E.; Leib, S. J.

    1993-01-01

    We consider the effects of a small-amplitude, steady, streamwise vorticity field on the flow over an infinitely thin flat plate in an otherwise uniform stream. We show how the initially linear perturbation, ultimately leads to a small-amplitude but nonlinear cross flow far downstream from the leading edge. This motion is imposed on the boundary-layer flow and eventually causes the boundary layer to separate. The streamwise velocity profiles within the boundary layer become inflexional in localized spanwise regions just upstream of the separation point. The flow in these regions is therefore susceptible to rapidly growing inviscid instabilities.

  9. Nanorod measurement-layer separate structure for nanorod-character measurement, simulation, and application as sensor devices

    NASA Astrophysics Data System (ADS)

    Leem, Myoung-Kun; Park, Jin-Uk; Kim, Chang-Man; Kim, Kyu-Jin; Yeom, Se-Hyuk; Choi, Woo-Youp; Kang, Won-Seok; Kim, Jae-Ho; Kang, Shin-Won

    2009-02-01

    This paper reported the simple nanorod characteristic measurement method by layer separated structure. The structures are designed by the ANSYS simulation and they are fabricated by semiconductor fabrications. In the experiment, dielectrophoresis (DEP) principle is used to assemble nanorods which are synthesized by electrochemical deposition (ECD) method. However, it is difficult to make devices without assembly process because nanorods which are synthesized by the ECD method are dispersed in the medium. Therefore, this paper was studied to design and fabricate the nanorod assembly-layer and measurement-layer separation. After assembling the nanorods, I-V characteristics of the nanorods were measured.

  10. Boundary layer separation on isolated boattail nozzles. M.S. Thesis; [conducted in the Langley 16-foot transonic wind tunnel

    NASA Technical Reports Server (NTRS)

    Abeyounis, W. K.

    1977-01-01

    The phenomenon of separated flow on a series of circular-arc afterbodies was investigated using the Langley 16-foot transonic tunnel at free-stream Mach numbers from 0.40 to 0.95 at 0 deg angle of attack. Both high-pressure air and solid circular cylinders with a diameter equal to the nozzle exit diameter were used to simulate jet exhausts. A detailed data base of boundary layer separation locations was obtained using oil-flow techniques. The results indicate that boundary layer separation is most extensive on steep boattails at high Mach numbers.

  11. Dielectric Barrier Discharge Ionization in Characterization of Organic Compounds Separated on Thin-Layer Chromatography Plates

    PubMed Central

    Cegłowski, Michał; Smoluch, Marek; Babij, Michał; Gotszalk, Teodor; Silberring, Jerzy; Schroeder, Grzegorz

    2014-01-01

    A new method for on-spot detection and characterization of organic compounds resolved on thin layer chromatography (TLC) plates has been proposed. This method combines TLC with dielectric barrier discharge ionization (DBDI), which produces stable low-temperature plasma. At first, the compounds were separated on TLC plates and then their mass spectra were directly obtained with no additional sample preparation. To obtain good quality spectra the center of a particular TLC spot was heated from the bottom to increase volatility of the compound. MS/MS analyses were also performed to additionally characterize all analytes. The detection limit of proposed method was estimated to be 100 ng/spot of compound. PMID:25170762

  12. Direct Numerical Simulation of an Adverse Pressure Gradient Turbulent Boundary Layer at the Verge of Separation

    NASA Astrophysics Data System (ADS)

    Kitsios, Vassili; Atkinson, Callum; Sillero, Juan; Guillem, Borrell; Gungor, Ayse; Jimenéz, Javier; Soria, Julio

    2014-11-01

    We investigate the structure of an adverse pressure gradient (APG) turbulent boundary layer (TBL) at the verge of separation. The intended flow is generated via direct numerical simulation (DNS). The adopted DNS code was previously developed for a zero pressure gradient TBL. Here the farfield boundary condition (BC) is modified to generate the desired APG flow. The input parameters required for the APG BC are initially estimated from a series of Reynolds Averaged Navier-Stokes simulations. The BC is implemented into the DNS code with further refinement of the BC performed. The behaviour of the large scale dynamics is illustrated via the extraction of coherent structures from the DNS using analysis of the velocity gradient tensor and vortex clustering techniques. The authors acknowledge the research funding from the Australian Research Council and European Research Council, and the computational resources provided by NCI and PRACE.

  13. Rigorous waveguiding analysis of the separated multiclad-layer stripe-geometry laser

    SciTech Connect

    Armann, M.C.

    1986-10-01

    The waveguide modes of separated multiclad-layer (SML) laser diodes are calculated accurately by means of laterally-coupled mode equations. Thereby, it is shown that the mode losses are appreciably higher as compared to previous calculations. In particular, enhancement of the mode losses in narrow-stripe SML lasers (..omega.. less than or equal to 5 ..mu..m) may explain the relatively high threshold currents and low efficiencies reported so far for AlGaAs-GaAs and InGaAsP-InP SML lasers. A detailed investigation of various geometries reveals this laser structure to equal the related channeled substrate planar (CSP) laser with respect to the waveguide losses.

  14. Effect of water separation layer on metal nanoforming process investigated using molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Wu, Cheng-Da; Chang Chin, Po-Yuan; Chiang, Chia-Chin; Lai, Rong-Jer; Fang, Te-Hua

    2013-11-01

    The effects of water separation layer and temperature on the nanoforming process of Al films are studied using molecular dynamics simulations. These effects are evaluated in terms of molecular/atomic trajectories, potential energy, slip vectors, and the radial distribution function. The simulation results show that Al films can automatically fill cavities via heating without requiring an external loading exerted on them. At the complete filling stage, the most compact structure is obtained for forming with no water; however, the pattern collapses during the demolding process due to strong adhesion with the mold. In nanoforming in a humid environment, water molecules between the mold and Al film act as a buffer which relieves the forming pressure on the Al film, slowing down the deformation. During demolding, the buffer effectively prevents the formation of pattern defects induced by adhesion. Water molecules gradually vaporize with increasing temperature, which causes pattern failure due to a decrease in humidity. Moderate water layers are beneficial for better order and a compact pattern structure.

  15. Separation of visibly-excited fluorescent components in fingerprint residue by thin-layer chromatography.

    PubMed

    Jones, N E; Davies, L M; Brennan, J S; Bramble, S K

    2000-11-01

    The use of lasers for the detection of fingermarks is widespread in the forensic field. Despite this, and the fact that many studies have been conducted into the composition of fingermark residue, the components responsible for the inherent visible fluorescence remain unidentified. Traditionally compositional studies have been performed on sweat, sebum, or skin surface washes, none of which are truly representative of the situation when a fingerprint is deposited on a surface. In this paper thin-layer chromatography (TLC) has been performed on sebum-rich fingermarks laid directly onto TLC plates and an argon ion laser used to visualize the separated components. It has been found to be a robust and reproducible method for studying the fluorescent components in fingermark residue and is considered to be more realistic than other methods of sample preparation as it eliminates the chances of extraneous matter being extracted from the skin surface. Investigations into the nature of the separated compounds have also been made and the results are reported. PMID:11110184

  16. Separation of transition and heavy metals using stationary phase gradients and thin layer chromatography.

    PubMed

    Stegall, Stacy L; Ashraf, Kayesh M; Moye, Julie R; Higgins, Daniel A; Collinson, Maryanne M

    2016-05-13

    Stationary phase gradients for chelation thin layer chromatography (TLC) have been investigated as a tool to separate a mixture of metal ions. The gradient stationary phases were prepared using controlled rate infusion (CRI) from precursors containing mono-, bi-, and tri-dentate ligands, specifically 3-aminopropyltriethoxysilane, N-[3-(trimethoxysilyl)propyl] ethylenediamine, and N-[3-(trimethoxysilyl)propyl] diethylenetriamine. The presence and the extent of gradient formation were confirmed using N1s X-ray photoelectron spectroscopy (XPS). XPS results showed that the degree of modification was dependent on the aminosilane precursor, its concentration, and the rate of infusion. The separation of four transition and heavy metals (Co(2+), Pb(2+), Cu(2+), and Fe(3+)) on gradient and uniformly modified plates was compared using a mobile phase containing a stronger chelating agent, ethylenediaminetetraacetic acid (EDTA). The retention of the metal ions was manipulated by varying the surface concentration of the chelating ligands. The order of retention on unmodified plates and on plates modified with a monodentate ligand was Fe(3+)>Cu(2+)∼Pb(2+)∼Co(2+), while the order of retention on plates modified with bi- and tri-dentate ligands was Fe(3+)>Cu(2+)>Pb(2+)∼Co(2+). Fe(3+) and Cu(2+) were much more sensitive to the concentration of chelating ligand on the surface (displaying lower Rf values with increasing ligand concentration) than Pb(2+) and Co(2+). Complete separation was achieved using a high concentration of the tridentate ligand coupled with a longer time for modification, yielding a retention order of Fe(3+)>Cu(2+)>Co(2+)>Pb(2+). PMID:27090390

  17. An ODE for boundary layer separation on a sphere and a hyperbolic space

    NASA Astrophysics Data System (ADS)

    Chan, Chi Hin; Czubak, Magdalena; Yoneda, Tsuyoshi

    2014-07-01

    Ma and Wang derived an equation linking the separation location and times for the boundary layer separation of incompressible fluid flows. The equation gave a necessary condition for the separation (bifurcation) point. The purpose of this paper is to generalize the equation to other geometries, and to phrase it as a simple ODE. Moreover we consider the Navie-Stokes equation with the Coriolis effect, which is related to the presence of trade winds on Earth. A ∂-singular point (bifurcation point) occurs at t0 iff a function α1(t) satisfies α1(t0)=0. The above result is a generalization of [10] which is considered in the Euclidean space R2. We can regard α1(t), α2(t) and α3(t) as a part of the inflow profile. However η(t) is not. Let us be more precise. Choose p˜∈∂K close to p0∈∂K, and let K˜≔{p∈M-K:d(p,p˜)0. It is reasonable to assume uθ does not grow polynomially for the r direction (this is due to the observation of the "boundary layer", since the flow should be a uniform one away from the boundary). Thus, it should be reasonable to focus on the following two cases: (Poiseuille type profile) -k2α1(t)+2kα2(t)<0 (α1(t)>0, α2(t)<0) and α3(t) is small comparing with α1(t) and α2(t). (Before separation profile) 2kα2(t)+α3(t)<0 (α2(t)>0, α3(t)<0) and α1(t) is small comparing with α2(t) and α3(t). In this point of view, the well-known physical phenomena of "adverse

  18. Open-loop control of noise amplification in a separated boundary layer flow

    SciTech Connect

    Boujo, E. Gallaire, F.; Ehrenstein, U.

    2013-12-15

    Linear optimal gains are computed for the subcritical two-dimensional separated boundary-layer flow past a bump. Very large optimal gain values are found, making it possible for small-amplitude noise to be strongly amplified and to destabilize the flow. The optimal forcing is located close to the summit of the bump, while the optimal response is the largest in the shear layer. The largest amplification occurs at frequencies corresponding to eigenvalues which first become unstable at higher Reynolds number. Nonlinear direct numerical simulations show that a low level of noise is indeed sufficient to trigger random flow unsteadiness, characterized here by large-scale vortex shedding. Next, a variational technique is used to compute efficiently the sensitivity of optimal gains to steady control (through source of momentum in the flow, or blowing/suction at the wall). A systematic analysis at several frequencies identifies the bump summit as the most sensitive region for control with wall actuation. Based on these results, a simple open-loop control strategy is designed, with steady wall suction at the bump summit. Linear calculations on controlled base flows confirm that optimal gains can be drastically reduced at all frequencies. Nonlinear direct numerical simulations also show that this control allows the flow to withstand a higher level of stochastic noise without becoming nonlinearly unstable, thereby postponing bypass transition. In the supercritical regime, sensitivity analysis of eigenvalues supports the choice of this control design. Full restabilization of the flow is obtained, as evidenced by direct numerical simulations and linear stability analysis.

  19. Open-loop control of noise amplification in a separated boundary layer flow

    NASA Astrophysics Data System (ADS)

    Boujo, E.; Ehrenstein, U.; Gallaire, F.

    2013-12-01

    Linear optimal gains are computed for the subcritical two-dimensional separated boundary-layer flow past a bump. Very large optimal gain values are found, making it possible for small-amplitude noise to be strongly amplified and to destabilize the flow. The optimal forcing is located close to the summit of the bump, while the optimal response is the largest in the shear layer. The largest amplification occurs at frequencies corresponding to eigenvalues which first become unstable at higher Reynolds number. Nonlinear direct numerical simulations show that a low level of noise is indeed sufficient to trigger random flow unsteadiness, characterized here by large-scale vortex shedding. Next, a variational technique is used to compute efficiently the sensitivity of optimal gains to steady control (through source of momentum in the flow, or blowing/suction at the wall). A systematic analysis at several frequencies identifies the bump summit as the most sensitive region for control with wall actuation. Based on these results, a simple open-loop control strategy is designed, with steady wall suction at the bump summit. Linear calculations on controlled base flows confirm that optimal gains can be drastically reduced at all frequencies. Nonlinear direct numerical simulations also show that this control allows the flow to withstand a higher level of stochastic noise without becoming nonlinearly unstable, thereby postponing bypass transition. In the supercritical regime, sensitivity analysis of eigenvalues supports the choice of this control design. Full restabilization of the flow is obtained, as evidenced by direct numerical simulations and linear stability analysis.

  20. Thermal stability and separation characteristics of anti-sticking layers of Pt/Cr films for the hot slumping technique

    NASA Astrophysics Data System (ADS)

    Ma, Shuang; Wen, Ming-Wu; Wang, Zhan-Shan

    2016-07-01

    The thermal stability and separation characteristics of anti-sticking layers of Pt/Cr films are studied in this paper. Several types of adhesion layers were investigated: 10.0 nm Pt, 1.5 nm Cr + 50.0 nm Pt, 2.5 nm Cr + 50.0 nm Pt and 3.5 nm Cr + 50.0 nm Pt fabricated using direct current magnetron sputtering. The variation of layer thickness, roughness, crystallization and surface topography of Pt/Cr films were analyzed by grazing incidence X-ray reflectometry, large angle X-ray diffraction and optical profiler before and after heating. 2.5 nm Cr + 50.0 nm Pt film exhibits the best thermal stability and separation characteristics according to the heating and hot slumping experiments. The film was also applied as an anti-sticking layer to optimize the maximum temperature of the hot slumping technique. Supported by CAS XTP project XDA04060605

  1. High-rate/high-temperature capability of a single-layer zicar-separator nickel-hydrogen cell

    NASA Technical Reports Server (NTRS)

    Wheeler, James R.

    1995-01-01

    A 50 Ampere-hour nickel-hydrogen cell with a single-layer Zircar separator stack design was fully charged and then discharged at a 2C current rate to an end voltage of 1 volt. This extreme test resulted in high temperatures which were recorded at three locations on the cell, i.e., the cell wall, the boss (barrel of the compression seal), and a terminal. The results provide new information about the high-temperature and high-discharge-rate capabilities of nickel-hydrogen cells. This information also adds to the growing data base for single-layer zirconium-oxide-cloth (Zircar) separator cell designs.

  2. A Resonant Pulse Detonation Actuator for High-Speed Boundary Layer Separation Control

    NASA Technical Reports Server (NTRS)

    Beck, B. T.; Cutler, A. D.; Drummond, J. P.; Jones, S. B.

    2004-01-01

    A variety of different types of actuators have been previously investigated as flow control devices. Potential applications include the control of boundary layer separation in external flows, as well as jet engine inlet and diffuser flow control. The operating principles for such devices are typically based on either mechanical deflection of control surfaces (which include MEMS flap devices), mass injection (which includes combustion driven jet actuators), or through the use of synthetic jets (diaphragm devices which produce a pulsating jet with no net mass flow). This paper introduces some of the initial flow visualization work related to the development of a relatively new type of combustion-driven jet actuator that has been proposed based on a pulse detonation principle. The device is designed to utilize localized detonation of a premixed fuel (Hydrogen)-air mixture to periodically inject a jet of gas transversely into the primary flow. Initial testing with airflow successfully demonstrated resonant conditions within the range of acoustic frequencies expected for the design. Schlieren visualization of the pulsating air jet structure revealed axially symmetric vortex flow, along with the formation of shocks. Flow visualization of the first successful sustained oscillation condition is also demonstrated for one configuration of the current test section. Future testing will explore in more detail the onset of resonant combustion and the approach to conditions of sustained resonant detonation.

  3. A simple and residual-layer-free solute-solvent separation soft lithography method

    NASA Astrophysics Data System (ADS)

    Dai, Xianglu; Xie, Huimin

    2015-09-01

    A solute-solvent separation soft lithography (3S soft lithography) is reported in this paper, which aims at offering a residual-layer-free micromachining technique that can be realized in an ordinary laboratory conveniently. In 3S soft lithography, a polydimethylsiloxane (PDMS) block containing micro-structure relief serves as the stamp, and the resist (as the solute) is dissolved in a solvent to form a solution before being molded by the stamp. During the molding process, the stamp absorbs the solvent and filters the resist; as a result, the resist can solidify on the substrate and replicate the pattern on the stamp. To improve the global geometric uniformity of the duplicated pattern, a hybrid PDMS stamp whose effectiveness is verified by the finite element analysis is used. Moreover, the liquid bridge phenomenon is creatively applied to remove the bubble defects caused during the molding process. The pattern transfer fidelity of 3S soft lithography is analyzed, and some suggestions are summarized for performing a high quality 3S soft lithography based on the experimental results. Verified by our experiment, the micro-structure fabricated by 3S soft lithography can serve as a mask for the following etching, and a lattice with minimum line width of 200 nm has been successfully fabricated on the silicon wafer in our study.

  4. Separation of non-stationary sound fields with single layer pressure-velocity measurements.

    PubMed

    Bi, Chuan-Xing; Geng, Lin; Zhang, Xiao-Zheng

    2016-02-01

    This paper examines the feasibility of extracting the non-stationary sound field generated by a target source in the presence of disturbing source from single layer pressure-velocity measurements. Unlike the method described in a previous paper [Bi, Geng, and Zhang, J. Acoust. Soc. Am. 135(6), 3474-3482 (2014)], the proposed method allows measurements of pressure and particle velocity signals on a single plane instead of pressure signals on two planes, and the time-dependent pressure generated by the target source is extracted by a simple superposition of the measured pressure and the convolution between the measured particle velocity and the corresponding impulse response function. Because the particle velocity here is measured directly, the error caused by the finite difference approximation can be avoided, which makes it possible to perform the separation better than the previous method. In this paper, a Microflown pressure-velocity probe is used to perform the experimental measurements, and the calibration procedure of the probe in the time domain is given. The experimental results demonstrate that the proposed method is effective in extracting the desired non-stationary sound field generated by the target source from the mixed one in both time and space domains, and it obtains more accurate results than the previous method. PMID:26936560

  5. A Laboratory Demonstration of the Three-Dimensional Nature of In-Line Holography.

    ERIC Educational Resources Information Center

    Baez, Albert V.; Castro, George

    1999-01-01

    Describes an experiment in which two semi-transparent reticles and a photographic plate separated by several centimeters are illuminated by a monochromatic point source in a typical in-line configuration that results in a hologram that contains information from both reticles. (Author/WRM)

  6. Computation of unsteady turbulent boundary layers with flow reversal and evaluation of two separate turbulence models

    NASA Technical Reports Server (NTRS)

    Cebeci, T.; Carr, L. W.

    1981-01-01

    A procedure which solves the governing boundary layer equations within Keller's box method was developed for calculating unsteady laminar flows with flow reversal. This method is extended to turbulent boundary layers with flow reversal. Test cases are used to investigate the proposition that unsteady turbulent boundary layers also remain free of singularities. Turbulent flow calculations are performed. The governing equations for both models are solved. As in laminar flows, the unsteady turbulent boundary layers are free from singularities, but there is a clear indication of rapid thickening of the boundary layer with increasing flow reversal. Predictions of both turbulence models are the same for all practical purposes.

  7. Dynamic layer-by-layer self-assembly of multi-walled carbon nanotubes on quartz wool for on-line separation of lysozyme in egg white.

    PubMed

    Du, Zhuo; Zhang, Suling; Zhou, Chanyuan; Liu, Miao; Li, Gongke

    2012-05-30

    The multi-walled carbon nanotubes (MWNTs) coated quartz wool (MWNTs/QW) prepared by dynamic layer-by-layer self-assembly was used as solid-phase extraction (SPE) absorbent for on-line separation and preconcentration of lysozyme in egg white. The coating procedures were performed continuously in a flow system operated by a set of sequential injection devices. The quartz wool was placed in a microcolumn forming a loose packing to guarantee the minimized flow impedance and the intimate contact between proteins and absorbent surface. Various parameters affecting SPE efficiency including the volume, pH, ionic strength and flow rate of sample and eluent were systematically studied. The feasibility of the proposed method was validated by successfully applied to the separation of lysozyme in egg white. PMID:22608421

  8. Separation of pigment formulations by high-performance thin-layer chromatography with automated multiple development.

    PubMed

    Stiefel, Constanze; Dietzel, Sylvia; Endress, Marc; Morlock, Gertrud E

    2016-09-01

    Food packaging is designed to provide sufficient protection for the respective filling, legally binding information for the consumers like nutritional facts or filling information, and an attractive appearance to promote the sale. For quality and safety of the package, a regular quality control of the used printing materials is necessary to get consistently good print results, to avoid migration of undesired ink components into the food and to identify potentially faulty ink batches. Analytical approaches, however, have hardly been considered for quality assurance so far due to the lack of robust, suitable methods for the analysis of rarely soluble pigment formulations. Thus, a simple and generic high-performance thin-layer chromatography (HPTLC) method for the separation of different colored pigment formulations was developed on HPTLC plates silica gel 60 by automated multiple development. The gradient system provided a sharp resolution for differently soluble pigment constituents like additives and coating materials. The results of multi-detection allowed a first assignment of the differently detectable bands to particular chemical substance classes (e.g., lipophilic components), enabled the comparison of different commercially available pigment batches and revealed substantial variations in the composition of the batches. Hyphenation of HPTLC with high resolution mass spectrometry and infrared spectroscopy allowed the characterization of single unknown pigment constituents, which may partly be responsible for known quality problems during printing. The newly developed, precise and selective HPTLC method can be used as part of routine quality control for both, incoming pigment batches and monitoring of internal pigment production processes, to secure a consistent pigment composition resulting in consistent ink quality, a faultless print image and safe products. Hyphenation of HPTLC with the A. fischeri bioassay gave first information on the bioactivity or rather

  9. Preparation of novel nanoporous layered silicates by swelling of AMH-3 and their use in nanocomposite membranes for gas separation

    NASA Astrophysics Data System (ADS)

    Choi, Sunho

    Nanoporous layered materials can be described as a class of lamellar solids that have an intermediate structure between layered materials (e.g., clays) and nanoporous frameworks (e.g., zeolites). Among these, nanoporous layered silicates have been studied for various industrial applications since the rich intercalation chemistry of clays can be applied to yield their swollen and exfoliated derivatives. Their pore connectivity in the direction perpendicular to the layers has been expected to provide an ability of molecular recognition based on the size of permeating species. These unique structural characteristics are important in the membrane industry because the molecular sieving of permeable nanolayers, if exfoliated and incorporated in polymers, is able to enhance the separation properties of polymeric membranes. AMH-3, a layered silicate built of nanoporous layers and interlayer space occupied by cations and water molecules, has been known to have a unique three-dimensional eight membered-ring (8 MR) pore system. Due to its unique porosity, it has been proposed to use exfoliated layers of AMH-3 as a selectivity-enhancing additive in polymers for small molecule separation. However, experimental procedures for the AMH-3 swelling, required for the nanocomposite demonstrated. This research reveals a novel process for AMH-3 swelling, involving the sequential intercalation of surfactant molecules following proton exchange of interlayer cations in the presence of amino acids. Structural information of swollen AMH-3 is investigated using various characterization techniques and the emergence of structural changes indicates that it should be considered as a new nanoporous layered silicate rather than a simple intercalated derivative. Consequently, polymeric nanocomposites incorporating the nanoparticles of swollen AMH-3 are fabricated by solution blending. These nanocomposite membranes present substantial improvements of the hydrogen/carbon dioxide ideal selectivity more

  10. Competitive separation of di- vs. mono-valent cations in electrodialysis: effects of the boundary layer properties.

    PubMed

    Kim, Younggy; Walker, W Shane; Lawler, Desmond F

    2012-05-01

    In electrodialysis desalination, the boundary layer near ion-exchange membranes is the limiting region for the overall rate of ionic separation due to concentration polarization over tens of micrometers in that layer. Under high current conditions, this sharp concentration gradient, creating substantial ionic diffusion, can drive a preferential separation for certain ions depending on their concentration and diffusivity in the solution. Thus, this study tested a hypothesis that the boundary layer affects the competitive transport between di- and mono-valent cations, which is known to be governed primarily by the partitioning with cation-exchange membranes. A laboratory-scale electrodialyzer was operated at steady state with a mixture of 10mM KCl and 10mM CaCl(2) at various flow rates. Increased flows increased the relative calcium transport. A two-dimensional model was built with analytical solutions of the Nernst-Planck equation. In the model, the boundary layer thickness was considered as a random variable defined with three statistical parameters: mean, standard deviation, and correlation coefficient between the thicknesses of the two boundary layers facing across a spacer. Model simulations with the Monte Carlo method found that a greater calcium separation was achieved with a smaller mean, greater standard deviation, or more negative correlation coefficient. The model and experimental results were compared for the cationic transport number as well as the current and potential relationship. The mean boundary layer thickness was found to decrease from 40 to less than 10 μm as the superficial water velocity increased from 1.06 to 4.24 cm/s. The standard deviation was greater than the mean thickness at slower water velocities and smaller at faster water velocities. PMID:22336628

  11. Turbulent boundary layer heat transfer experiments - A separate effects study on a convexly-curved wall

    NASA Technical Reports Server (NTRS)

    Simon, T. W.; Moffat, R. J.

    1981-01-01

    Surface heat transfer rates have been measured for several different flows on an isothermal, convexly curved surface. The freestream velocity, boundary layer thickness, acceleration parameter, and unheated starting length were varied systematically, and both turbulent and transitional boundary layers were studied. The effect of convex curvature on heat transfer rates is significant with Stanton numbers reduced 20-25% below flat wall values for the same enthalpy thickness Reynolds number. Heat transfer rates recovered slowly on a flat wall downstream of the curved wall, and after 60 cm, the Stanton numbers were still 15-20% below flat wall values. The behavior of the boundary layer suggests the existence of an asymptotic condition. Boundary layer thickness, freestream velocity, and boundary layer maturity affect the initial response to the introduction of curvature and the rate at which the asymptotic state is approached. Convex curvature appears to increase the boundary layer's sensitivity to acceleration; it also delays and retards transition. Near-laminar or early-transitional boundary layers recover from curvature rapidly, whereas late-transitional and mature boundary layers recover slowly.

  12. Superconductivity in KCa2Fe4As4F2 with Separate Double Fe2As2 Layers.

    PubMed

    Wang, Zhi-Cheng; He, Chao-Yang; Wu, Si-Qi; Tang, Zhang-Tu; Liu, Yi; Ablimit, Abduweli; Feng, Chun-Mu; Cao, Guang-Han

    2016-06-29

    We report the synthesis, crystal structure, and physical properties of a quinary iron arsenide fluoride, KCa2Fe4As4F2. The new compound crystallizes in a body-centered tetragonal lattice (space group I4/mmm, a = 3.8684(2) Å, c = 31.007(1) Å, Z = 2) that contains double Fe2As2 conducting layers separated by insulating Ca2F2 layers. Our measurements of electrical resistivity, direct-current magnetic susceptibility, and heat capacity demonstrate bulk superconductivity at 33 K in KCa2Fe4As4F2. PMID:27321364

  13. Drag Reduction by Suction of the Boundary Layer Separated Behind Shock Wave Formation at High Mach Numbers

    NASA Technical Reports Server (NTRS)

    Regenscheit, B.

    1947-01-01

    With an approach of the velocity of flight of a ship to the velocity of sound, there occurs a considerable increase of the drag. The reason for this must be found in the boundary layer separation caused by formation of shock waves. It will be endeavored to reduce the drag increase by suction of the boundary layer. Experimental results showed that drag increase may be considerably reduced by this method. It was, also, observed that, by suction, the position of shock waves can be altered to a considerable extent.

  14. Separation and electrical properties of self-organized graphene/graphite layers

    NASA Astrophysics Data System (ADS)

    Mailian, Manuel R.; Mailian, Aram R.

    2015-02-01

    Intrinsic layered structure of graphite is the source of ongoing and expanding search of ways of obtaining low-cost and promising graphite thin layers. We report on a novel method of obtaing and seperating rubbed graphite sheets by using water soluble NaCl substrate. The electrical behavior of sheets was characterized by current-voltage measurements. An in-plane electrical anisotropy depending on rubbing direction is discovered. Optical microscopy observations combined with discovered non-linear electrical behavior revealed that friction leads to the formation of sheet makeup which contain an optically transparent lamina of self-organized few-layer graphene.

  15. Computation of the shock-wave boundary layer interaction with flow separation

    NASA Technical Reports Server (NTRS)

    Ardonceau, P.; Alziary, T.; Aymer, D.

    1980-01-01

    The boundary layer concept is used to describe the flow near the wall. The external flow is approximated by a pressure displacement relationship (tangent wedge in linearized supersonic flow). The boundary layer equations are solved in finite difference form and the question of the presence and unicity of the solution is considered for the direct problem (assumed pressure) or converse problem (assumed displacement thickness, friction ratio). The coupling algorithm presented implicitly processes the downstream boundary condition necessary to correctly define the interacting boundary layer problem. The algorithm uses a Newton linearization technique to provide a fast convergence.

  16. EphrinB/EphB Signaling Controls Embryonic Germ Layer Separation by Contact-Induced Cell Detachment

    PubMed Central

    Rohani, Nazanin; Canty, Laura; Luu, Olivia

    2011-01-01

    Background The primordial organization of the metazoan body is achieved during gastrulation by the establishment of the germ layers. Adhesion differences between ectoderm, mesoderm, and endoderm cells could in principle be sufficient to maintain germ layer integrity and prevent intermixing. However, in organisms as diverse as fly, fish, or amphibian, the ectoderm-mesoderm boundary not only keeps these germ layers separated, but the ectoderm also serves as substratum for mesoderm migration, and the boundary must be compatible with repeated cell attachment and detachment. Principal Findings We show that localized detachment resulting from contact-induced signals at the boundary is at the core of ectoderm-mesoderm segregation. Cells alternate between adhesion and detachment, and detachment requires ephrinB/EphB signaling. Multiple ephrinB ligands and EphB receptors are expressed on each side of the boundary, and tissue separation depends on forward signaling across the boundary in both directions, involving partially redundant ligands and receptors and activation of Rac and RhoA. Conclusion This mechanism differs from a simple differential adhesion process of germ layer formation. Instead, it involves localized responses to signals exchanged at the tissue boundary and an attachment/detachment cycle which allows for cell migration across a cellular substratum. PMID:21390298

  17. In-line monitoring of (MR) fluid properties

    NASA Astrophysics Data System (ADS)

    Kordonski, William; Gorodkin, Sergei; Behlok, Ray

    2015-05-01

    Proper functionality of devices and processes based on (MR) fluids greatly depends, along with other factors, on stability of fluid characteristics such as concentration of magnetic particles and magnetic properties of the particles. The concentration of magnetic particles may change due to evaporation or leakage of carrier fluid, as well as particle sedimentation. Magnetic properties may change due to temperature, corrosion of particles or irreversible aggregation. In-line noninvasive monitoring of particle concentration and magnetic properties allows, in one way or another, compensation for the impact of destabilizing factors and provides system stable output. Two novel methods of in-line measurement of MR fluid magnetic permeability or magnetic particle concentration are considered in this presentation. The first one is based on the principle of mutual inductance and is intended for monitoring MR fluid flowing in pipes or channels. In the second one, permeability is measured by a flash-mount sensor which reacts on changes in the reluctance of the MR fluid layer adjacent to the wall. The use of the methods for stabilization of the material removal rate in high precision finishing process employing aqueous MR fluid is discussed.

  18. Polymer Solar Cell Device Characteristics Are Independent of Vertical Phase Separation in Active Layers

    NASA Astrophysics Data System (ADS)

    Loo, Yueh-Lin

    2013-03-01

    Preferential segregation of organic semiconductor constituents in multicomponent thin-film active layers has long been speculated to affect the characteristics of bulk-heterojunction polymer solar cells. Using soft-contact lamination and delamination schemes - with which we have been able to remove compositionally well characterized polymer thin films, flip them over so as to reverse their composition profiles, and then transfer them onto existing device platforms - we showed unambiguously that the device performance of P3HT:PCBM solar cells are independent of the interfacial segregation characteristics of the active layers. Temperature-dependent single-carrier diode measurements of the organic semiconductor constituents suggest that the origin of this invariance stems from the fact that P3HT comprises a high density of mid-gap states. Hole carriers in these mid-gap states can in turn recombine with electrons at the electron-collecting interface, effectively promoting electron transfer from the cathode to the active layer.

  19. Thermodynamical effects accompanied freezing of two water layers separated by sea ice sheet

    NASA Astrophysics Data System (ADS)

    Bogorodsky, Petr; Marchenko, Aleksey

    2014-05-01

    The process of melt pond freezing is very important for generation of sea ice cover thermodynamic and mass balance during winterperiod. However, due to significant difficulties of field measurements the available data of model estimations still have no instrumental confirmation. In May 2009 the authors carried out laboratory experiment on freezing of limited water volume in the University Centre in Svalbard ice tank. In the course of experiment fresh water layer of 27.5 cm thickness at freezing point poured on the 24 cm sea ice layer was cooled during 50 hours at the temperature -10º C and then once again during 60 hours at -20º C. For revealing process typical characteristics the data of continuous measurements of temperature and salinity in different phases were compared with data of numerical computations obtained with thermodynamic model which was formulated in the frames of 1-D equation system (infinite extension of water freezing layer) and adapted to laboratory conditions. The known surprise of the experiment became proximity of calculated and measured estimates of process dynamics that confirmed the adequacy of the problem mathematical statement (excluding probably process finale stage). This effect can be explained by formation of cracks on the upper layer of ice at sharp decreases of air temperature, which temporary compensated hydrostatic pressure growth during freezing of closed water volume. Another compensated mechanism can be migration of brine through the lower layer of ice under influence of vertical pressure gradient and also rejection of gas dissolved in water which increased its compressibility. During 110 hours cooling thickness of water layer between ice layers reduced approximately to 2 cm. According to computations this layer is not chilled completely but keeps as thin brine interlayer within ice body whose thickness (about units of mm) is determined by temperature fluctuations of cooled surface. Nevertheless, despite good coincidence of

  20. Mechanism of shock unsteadiness in separated shock/boundary-layer interactions

    NASA Astrophysics Data System (ADS)

    Agostini, L.; Larchevêque, L.; Dupont, P.

    2015-12-01

    A large-eddy simulation-based study is presented and focuses on different unsteadiness-source features in a Mach 2.3 shock reflection with separation. The sources of unsteadiness are localized and the path taken by disturbance as it spreads out to the whole field is defined. It is shown that the phenomena arising inside the recirculation bubble govern the whole interaction, at both low and intermediate frequencies. Indeed, the shock motion appears to mirror phenomena found in the separated zone. Moreover, features of separated-flow unsteadiness bear some resemblance to those occurring in incompressible flows. An equivalent inviscid scheme of the unsteady interaction is established in order to describe the whole shock-system unsteadiness at low and intermediate frequencies and the downstream unsteady-pressure field.

  1. What Factors Affect the Separation of Substances Using Thin-Layer Chromatography? An Undergraduate Experiment.

    ERIC Educational Resources Information Center

    Nash, John J.; Meyer, Jeanne A.; Everson, Barbara

    2001-01-01

    Rx values in thin-layer chromatography (TLC) depend strongly on the solvent saturation of the atmosphere above the liquid in the TLC developing chamber. Presents an experiment illustrating the potentially dramatic effects on TLC Rx values of not equilibrating the solvent atmosphere during development. (ASK)

  2. Molecular simulation of adsorption and separation of mixtures of short linear alkanes in pillared layered materials at ambient temperature.

    PubMed

    Li, Wen-Zhuo; Liu, Zi-Yang; Che, Yu-Liang; Zhang, Dan

    2007-08-15

    Grand canonical Monte Carlo and configurational-bias Monte Carlo techniques are carried out to simulate the adsorption of ternary and quaternary mixtures of short linear alkanes, involving methane, ethane, propane, and n-butane, in pillared layered materials at ambient temperature, T=300 K. In the simulation, a pillared layered pore is modeled by a uniform distribution of pillars between two layered walls built by making two separate talc lamellas parallel each other with a given size of interlayer distance. The interaction between fluid molecules and two layered walls is measured by storing potentials calculated in advance at a series of grid points. The interaction between fluid molecules and pillars is also calculated by a site-to-site method. The potential model proposed in this work is proved to be effective because of the simulation result being good agreement with the experimental data for the adsorption of nitrogen at 77 K. Then, the adsorption isotherms of mixtures of short linear alkanes in pillared layered pores with three different porosities psi=0.98, 0.93 and 0.85, and three pore widths H=1.02, 1.70 and 2.38 nm at 300 K are obtained by taking advantage of the model. The simulation results tell us that the longer chain component is preferentially adsorbed at low pressures, and its adsorption increases and then decreases as the pressure increases while the shorter chain component is still adsorbed at high pressures. Moreover, the sorption selectivity of pillared layered materials for the longest chain component in alkane mixtures increases as the mole fraction of methane in the gas phase increases. The selectivity of pillared layered materials for the longest chain component in alkane mixtures also increases as the pore width decreases and the porosity increases. PMID:17482203

  3. In-line powder coating of pultrusions

    SciTech Connect

    Spoo, K.; Smith, G.

    1996-11-01

    This paper discusses the pros and cons of an in-line powder coating process that applies an acrylic modified polyurethane powder to pultruded window lineals. The system applies the finish to the pultruded part downstream from the pultrusion die. Capital costs, direct costs, and mechanics of the process are discussed.

  4. IMPROVED THIN-LAYER CHROMATOGRAPHIC SEPARATION OF 32P-POSTLABELING DNA ADDUCTS

    EPA Science Inventory

    DNA adducts represent the putative initiating event in the chemical process. 2P-Postlabeling is one of several assayswhich have been developed for the sensitive detection of DNA adducts. n integral part of the 32p-postlabeling assay is the separation of adducted nucleotides by mu...

  5. Separation of the Carotenoid Bixin from Annatto Seeds Using Thin-Layer and Column Chromatography

    ERIC Educational Resources Information Center

    McCullagh, James V.; Ramos, Nicholas

    2008-01-01

    In this experiment the carotenoid bixin is isolated from annatto ("Bixa orellana") seeds using column chromatography. The experiment has several key advantages over previous pigment separation experiments. First, unlike other experiments significant quantities of the carotenoid (typically 20 to 25 mg) can be isolated from small quantities of plant…

  6. Three-layered absorptive glass mat separator with membrane for application in valve-regulated lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Naidenov, V.; Pavlov, D.; Cherneva, M.

    During charge and discharge of the lead-acid cell equal amounts of H 2SO 4 participate in the reactions at the two types of plates (electrodes). However, the charge and discharge reactions at the positive plates involve also 2 mol of water per every mole of reacted PbO 2. Consequently, a concentration difference appears in the electrolyte between the two electrodes (horizontal stratification), which affects the reversibility of the processes at the two electrodes and thus the cycle life of the battery. The present paper proposes the use of a three-layered absorptive glass mat (AGM) separator, the middle layer playing the role of a membrane that divides (separates) the anodic and cathodic electrolyte spaces, and controls the exchange rates of H 2SO 4, H + ions, O 2 and H 2O flows between the two electrode spaces. To be able to perform this membrane function, the thinner middle AGM layer (0.2 mm) is processed with an appropriate polymeric emulsion to acquire balanced hydrophobic/hydrophilic properties, which sustain constant H 2SO 4 concentration in the two electrode spaces during cycling. Three types of polymeric emulsions have been used for treatment of the membrane: (a) polyvinylpyrollidonestyrene (MPVS), (b) polyvinylpyrrolidone "Luviskol" (MPVP), or (c) polytetrafluorethylene modified with Luviskol (MMAGM). It is established experimentally that the MMAGM membrane maintains equal acid concentration in the anodic and cathodic spaces (no horizontal stratification) during battery cycling and hence ensures longer cycle life performance.

  7. Fluorescence enhancement of photosynthetic complexes separated from nanoparticles by a reduced graphene oxide layer

    NASA Astrophysics Data System (ADS)

    Twardowska, Magdalena; Kamińska, Izabela; Wiwatowski, Kamil; Ashraf, Khuram U.; Cogdell, Richard J.; Mackowski, Sebastian; Niedziółka-Jönsson, Joanna

    2014-03-01

    We observe that introducing a layer of reduced graphene oxide between electrochemically deposited gold nanoparticles and natural photosynthetic Fenna-Matthews-Olson (FMO) complex from green sulfur bacteria, results in an increase of the fluorescence emission of the FMO. This increase is not accompanied with any substantial change of the fluorescence dynamics. Our findings indicate that incorporating graphene-based materials in hybrid assemblies yields better performance of such structures, thus holds promise for designing biosensing and optoelectronic devices.

  8. Formation of separating layers under conditions of the thermal aging of sorbents modified by fluorinated polyimide

    NASA Astrophysics Data System (ADS)

    Yakovleva, E. Yu.; Shundrina, I. K.; Gerasimov, E. Yu.; Vaganova, T. A.

    2014-03-01

    Thermogravimetry, elemental analysis, low-temperature nitrogen adsorption, high-resolution electron microscopy, and gas chromatography are used to study the effect of the content of perfluorinated polyimide when used as a stationary phase for modifying Chromosorb P NAW diatomite supports and aluminum oxide, and the effect of thermal aging conditions on changes in their texture and chromatographic characteristics. It is shown that Chromosorb P NAW + 5 wt % of polyimide (PI) adsorbent thermally aged at 700°C in a flow of inert gas exhibits properties of carbon molecular sieves, while aluminum oxide impregnated with 10 wt % of PI and thermally aged at 250°C allows us to selectively separate permanent and organic gases, as well separate saturated and unsaturated hydrocarbons.

  9. Model analysis of separate-confinement heterojunction lasers with inhomogeneous cladding layers

    SciTech Connect

    Streifer, W.; Burnham, R.D.; Scifres, D.R.

    1983-05-01

    Separate-confinement heterostructure lasers with thin active regions are analyzed. For four different interior-cladding-region refractive-index spatial variations, i.e., step, triangular, parabolic, and inverted parabolic, wave-guide modes are calculated and thresholds are compared. Based on optical considerations alone, the step-index profile has the lowest threshold; however, for optimum cladding thicknesses the differences are not great.

  10. Separation by thin-layer chromatography and structure elucidation of bilirubin conjugates isolated from dog bile.

    PubMed Central

    Heirwegh, K P; Fevery, J; Michiels, R; van Hees, G P; Compernolle, F

    1975-01-01

    1. A system for separation of bile pigments by t.l.c. and for their structure elucidation is presented. Separated bile pigments are characterized by t.l.c. of derived dipyrrolic azopigments. 2. At the tetrapyrrolic stage hydrolysis in strongly alkaline medium followed by t.l.c. demonstrates the presence of bilirubin-IIIalpha, -IXalpha and -XIIIalpha and allows assessment of their relative amounts. 3. Most structural information is derived from analysis of dipyrrolic azopigments. Such derivatives, obtained by treatment of separated bile pigments with diazotized ethyl anthranilate, were separated and purified by t.l.c. Micro methods showed (a) the nature of the dipyrrolic aglycone, (b) the nature of the bonds connecting aglycone to a conjugating group, (c) the ratio of vinyl/isovinyl isomers present in the aglycone and, (d) the nature of the conjugating groups (by suitable derivative formation and t.l.c. with reference to known compounds). 4. In bile of normal dogs at least 20 tetrapyrrolic, diazo-positive bile pigments could be recognized. Except for two pigments the tetrapyrrolic nucleus corresponded predominantly to bilirubin-IXalpha. All conjugated pigments had their conjugating groups connected in ester linkage to the tetrapyrrolic aglycone, Apart from bilirubin-IXalpha, monoconjugates and homogeneous and mixed diconjugates of bilirubin were demonstrated; conjugating groups of major importance were xylose, glucose and glucuronic acid. 5. Bilirubin isomer determination on native bile and isolated bile pigments, and dipyrrole-exchange assays with [14C8]bilirubin indicated (a) that the conjugates pre-exist in bile, and (b) that no significant dipyrrole exchange occurs during isolation of the pigments. PMID:1156357

  11. Rational Integration of Polypropylene/Graphene Oxide/Nafion as Ternary-Layered Separator to Retard the Shuttle of Polysulfides for Lithium-Sulfur Batteries.

    PubMed

    Zhuang, Ting-Zhou; Huang, Jia-Qi; Peng, Hong-Jie; He, Lian-Yuan; Cheng, Xin-Bing; Chen, Cheng-Meng; Zhang, Qiang

    2016-01-20

    The reversible electrochemical transformation from lithium (Li) and sulfur (S) into Li2 S through multielectron reactions can be utilized in secondary Li-S batteries with very high energy density. However, both the low Coulombic efficiency and severe capacity degradation limits the full utilization of active sulfur, which hinders the practical applications of Li-S battery system. The present study reports a ternary-layered separator with a macroporous polypropylene (PP) matrix layer, graphene oxide (GO) barrier layer, and Nafion retarding layer as the separator for Li-S batteries with high Coulombic efficiency and superior cyclic stability. In the ternary-layered separator, ultrathin layer of GO (0.0032 mg cm(-2) , estimated to be around 40 layers) blocks the macropores of PP matrix, and a dense ion selective Nafion layer with a very low loading amount of 0.05 mg cm(-2) is attached as a retarding layer to suppress the crossover of sulfur-containing species. The ternary-layered separators are effective in improving the initial capacity and the Coulombic efficiency of Li-S cells from 969 to 1057 mAh g(-1) , and from 80% to over 95% with an LiNO3 -free electrolyte, respectively. The capacity degradation is reduced from 0.34% to 0.18% per cycle within 200 cycles when the PP separator is replaced by the ternary-layered separators. This work provides the rational design strategy for multifunctional separators at cell scale to effective utilizing of active sulfur and retarding of polysulfides, which offers the possibility of high energy density Li-S cells with long cycling life. PMID:26641415

  12. Three separate ion populations observed simultaneously in the plasma sheet boundary layer in the distant geomagnetic tail

    NASA Astrophysics Data System (ADS)

    Saito, Yoshifumi; Mukai, Toshifumi; Terasawa, Toshio; Machida, Shinobu

    2004-04-01

    The detailed structure of ion velocity space distributions in the plasma sheet boundary layer (PSBL) in the distant geomagnetic tail has been investigated. Three separate, tailward-streaming ion populations have been observed simultaneously in PSBL crossings in which the inner edge of the PSBL was identified as a slow mode shock: cold, low-energy, ions presumably of ionospheric origin that fill much of the tail lobes, and two more energetic populations. The more energetic of these latter populations, which was concentrated in the outer (lobe) layers of the PSBL, had a ``kidney bean'' shape. The less energetic population had a well-defined low-energy cutoff that decreased with increasing penetration into the PSBL from the lobe. The sources of these two populations may be cold lobe ions accelerated in the current sheet near the distant neutral line and plasma sheet ions that leak across the shock, respectively.

  13. The influence of free-stream turbulence on separation of turbulent boundary layers in incompressible, two-dimensional flow

    NASA Technical Reports Server (NTRS)

    Potter, J. Leith; Barnett, R. Joel; Fisher, Carl E.; Koukousakis, Costas E.

    1986-01-01

    Experiments were conducted to determine if free-stream turbulence scale affects separation of turbulent boundary layers. In consideration of possible interrelation between scale and intensity of turbulence, the latter characteristic also was varied and its role was evaluated. Flow over a 2-dimensional airfoil in a subsonic wind tunnel was studied with the aid of hot-wire anemometry, liquid-film flow visualization, a Preston tube, and static pressure measurements. Profiles of velocity, relative turbulence intensity, and integral scale in the boundary layer were measured. Detachment boundary was determined for various angles of attack and free-stream turbulence. The free-stream turbulence intensity and scale were found to spread into the entire turbulent boundary layer, but the effect decreased as the airfoil surface was approached. When the changes in stream turbulence were such that the boundary layer velocity profiles were unchanged, detachment location was not significantly affected by the variations of intensity and scale. Pressure distribution remained the key factor in determining detachment location.

  14. Long-range coupling of electron-hole pairs in spatially separated organic donor-acceptor layers

    PubMed Central

    Nakanotani, Hajime; Furukawa, Taro; Morimoto, Kei; Adachi, Chihaya

    2016-01-01

    Understanding exciton behavior in organic semiconductor molecules is crucial for the development of organic semiconductor-based excitonic devices such as organic light-emitting diodes and organic solar cells, and the tightly bound electron-hole pair forming an exciton is normally assumed to be localized on an organic semiconducting molecule. We report the observation of long-range coupling of electron-hole pairs in spatially separated electron-donating and electron-accepting molecules across a 10-nanometers-thick spacer layer. We found that the exciton energy can be tuned over 100 megaelectron volts and the fraction of delayed fluorescence can be increased by adjusting the spacer-layer thickness. Furthermore, increasing the spacer-layer thickness produced an organic light-emitting diode with an electroluminescence efficiency nearly eight times higher than that of a device without a spacer layer. Our results demonstrate the first example of a long-range coupled charge-transfer state between electron-donating and electron-accepting molecules in a working device. PMID:26933691

  15. Analysis of the separated boundary layer flow on the surface and in the wake of blunt trailing edge airfoils

    NASA Technical Reports Server (NTRS)

    Goradia, S. H.; Mehta, J. M.; Shrewsbury, G. S.

    1977-01-01

    The viscous flow phenomena associated with sharp and blunt trailing edge airfoils were investigated. Experimental measurements were obtained for a 17 percent thick, high performance GAW-1 airfoil. Experimental measurements consist of velocity and static pressure profiles which were obtained by the use of forward and reverse total pressure probes and disc type static pressure probes over the surface and in the wake of sharp and blunt trailing edge airfoils. Measurements of the upper surface boundary layer were obtained in both the attached and separated flow regions. In addition, static pressure data were acquired, and skin friction on the airfoil upper surface was measured with a specially constructed device. Comparison of the viscous flow data with data previously obtained elsewhere indicates reasonable agreement in the attached flow region. In the separated flow region, considerable differences exist between these two sets of measurements.

  16. Unsteady inflow effects on the wake shed from a high-lift LPT blade subjected to boundary layer laminar separation

    NASA Astrophysics Data System (ADS)

    Satta, Francesca; Ubaldi, Marina; Zunino, Pietro

    2012-04-01

    An experimental investigation on the near and far wake of a cascade of high-lift low-pressure turbine blades subjected to boundary layer separation over the suction side surface has been carried out, under steady and unsteady inflows. Two Reynolds number conditions, representative of take-off/landing and cruise operating conditions of the real engine, have been tested. The effect of upstream wake-boundary layer interaction on the wake shed from the profile has been investigated in a three-blade large-scale linear turbine cascade. The comparison between the wakes shed under steady and unsteady inflows has been performed through the analysis of mean velocity and Reynolds stress components measured at midspan of the central blade by means of a two-component crossed miniature hot-wire probe. The wake development has been analyzed in the region between 2% and 100% of the blade chord from the central blade trailing edge, aligned with the blade exit direction. Wake integral parameters, half-width and maximum velocity defects have been evaluated from the mean velocity distributions to quantify the modifications induced on the vane wake by the upstream wake. Moreover the thicknesses of the two wake shear layers have been considered separately in order to identify the effects of Reynolds number and incoming flow on the wake shape. The self-preserving state of the wake has been looked at, taking into account the different thicknesses of the two shear layers. The evaluation of the power density spectra of the velocity fluctuations allowed the study of the wake unsteady behavior, and the detection of the effects induced by the different operating conditions on the trailing edge vortex shedding.

  17. Enhanced cycle performance of lithium-sulfur batteries using a separator modified with a PVDF-C layer.

    PubMed

    Wei, Hang; Ma, Jin; Li, Biao; Zuo, Yuxuan; Xia, Dingguo

    2014-11-26

    High energy density Li-S batteries are highly attractive. However, their use in practical applications has been greatly affected by their poor cycle life and low rate performance, which can be partly attributed to the dissolution of polysulfides from the S cathode and their migration to the Li anode through the separator. While much effort has been devoted to designing the structure of the S cathodes for suppressing the dissolution of polysulfides, relatively little emphasis has been placed on modifying the separator. Herein, we demonstrate a new approach for modifying the separator with a polyvinylidene fluoride-carbon (PVDF-C) layer, where the polysulfides generated in the Li-S cells can be localized on the cathode side. Li-S batteries based on the novel separator and a cathode prepared by the simple mixing of a S powder and super P have delivered discharge capacities of 918.6 mAh g(-1), 827.2 mAh g(-1), and 669.1 mAh g(-1) after 100, 200, and 500 cycles, respectively, at a discharge rate of 0.5 C. Even under current densities of up to 5 C, the cells were able to retain a discharge capacity of 393 mAh g(-1), thereby demonstrating an excellent high rate performance and stability. The exceptional electrochemical performance could be attributed to the intense adsorption capability of the micropores, presence of C-C double bonds, and conductivity of the C network in the PVDF-C layer. This economical and simple strategy to overcome the polysulfide dissolution issues provides a commercially feasible method for the construction of Li-S batteries. PMID:25275455

  18. Confined phase separation in SiO{sub X} nanometric thin layers

    SciTech Connect

    Roussel, M.; Talbot, E.; Pareige, C.; Pareige, P.; Pratibha Nalini, R.; Gourbilleau, F.

    2013-11-11

    Phase separation in silicon-rich silica/silica multilayers was investigated using Atom Probe Tomography and Atomistic Kinetic Monte Carlo simulation. It is shown that the thickness of silicon-rich silicon oxide sublayers plays an important role during phase transformation. It determines the morphology of Si-rich phase formed after subsequent annealing, which is of prime interest for microelectronic and optoelectronic applications. Monte Carlo simulation reveals that the formation of isolated Si clusters can be achieved even in the case of spinodal decomposition and is directly related to the ratio between the spinodal wavelength and the sublayer thickness.

  19. In-line assay monitor for uranium hexafluoride

    DOEpatents

    Wallace, S.A.

    1980-03-21

    An in-line assay monitor for determining the content of uranium-235 in a uranium hexafluoride gas isotopic separation system is provided which removes the necessity of complete access to the operating parameters of the system for determining the uranium-235 content. The method and monitor for carrying out the method involve cooling of a radiation pervious chamber connected in fluid communication with the selected point in the system to withdraw a specimen and solidify the specimen in the chamber. The specimen is irradiated by means of an ionizing radiation source of energy different from that of the 185 keV gamma emissions from uranium-235. The uranium-235 content of the specimen is determined from comparison of the accumulated 185 keV energy counts and reference energy counts. The latter is used to measure the total uranium isotopic content of the specimen.

  20. Evaluation of turbulence models for prediction of separated turbulent boundary layer under unsteady adverse pressure gradients

    NASA Astrophysics Data System (ADS)

    Park, Junshin; You, Donghyun

    2014-11-01

    Predicitive capabilites of Reynolds-averaged Navier-Stokes (RANS) techniques for separated flow under unsteady adverse pressure gradients have been assessed using SST k - ω model and Spalart-Allmaras model by comparing their results with direct numerical simulation (DNS) results. Both DNS and RANS have been conducted with a zero pressure gradient, a steady adverse pressure gradient, and an unsteady adverse pressure gradient, respectively. Comparative studies show that both RANS models predict earlier separation and fuller velocity profiles at the reattachment zone than DNS in the unsteady case, while reasonable agreements with DNS are observed for steady counterparts. Causes for differences in the predictive capability of RANS for steady and unsteady cases, are explained by examining the Reynolds stress term and eddy viscosity term in detail. The Reynolds stress and eddy viscosity are under-predicted by both RANS models in the unsteady case. The origin of the under-prediction of the Reynolds stress with both RANS models is revealed by investigating Reynolds stress budget terms obtained from DNS. Supported by the National Research Foundation of Korea Grant NRF-2012R1A1A2003699 and the Brain Korea 21+ program.

  1. Predictions of Separated and Transitional Boundary Layers Under Low-Pressure Turbine Airfoil Conditions Using an Intermittency Transport Equation

    NASA Technical Reports Server (NTRS)

    Suzen, Y. B.; Huang, P. G.; Hultgren, Lennart S.; Ashpis, David E.

    2003-01-01

    A new transport equation for the intermittency factor was proposed to predict separated and transitional boundary layers under low-pressure turbine airfoil conditions. The intermittent behavior of the transitional flows is taken into account and incorporated into computations by modifying the eddy viscosity, t , with the intermittency factor, y. Turbulent quantities are predicted by using Menter s two-equation turbulence model (SST). The intermittency factor is obtained from a transport equation model, which not only can reproduce the experimentally observed streamwise variation of the intermittency in the transition zone, but also can provide a realistic cross-stream variation of the intermittency profile. In this paper, the intermittency model is used to predict a recent separated and transitional boundary layer experiment under low pressure turbine airfoil conditions. The experiment provides detailed measurements of velocity, turbulent kinetic energy and intermittency profiles for a number of Reynolds numbers and freestream turbulent intensity conditions and is suitable for validation purposes. Detailed comparisons of computational results with experimental data are presented and good agreements between the experiments and predictions are obtained.

  2. Predictions of Separated and Transitional Boundary Layers Under Low-Pressure Turbine Airfoil Conditions Using an Intermittency Transport Equation

    NASA Technical Reports Server (NTRS)

    Suzen, Y. Bora; Huang, P. G.; Hultgren, Lennart S.; Ashpis, David E.

    2001-01-01

    A new transport equation for the intermittency factor was proposed to predict separated and transitional boundary layers under low-pressure turbine airfoil conditions. The intermittent behavior of the transitional flows is taken into account and incorporated into computations by modifying the eddy viscosity, mu(sub t), with the intermittency factor, gamma. Turbulent quantities are predicted by using Menter's two-equation turbulence model (SST). The intermittency factor is obtained from a transport equation model, which not only can reproduce the experimentally observed streamwise variation of the intermittency in the transition zone, but also can provide a realistic cross-stream variation of the intermittency profile. In this paper, the intermittency model is used to predict a recent separated and transitional boundary layer experiment under low pressure turbine airfoil conditions. The experiment provides detailed measurements of velocity, turbulent kinetic energy and intermittency profiles for a number of Reynolds numbers and freestream turbulent intensity conditions and is suitable for validation purposes. Detailed comparisons of computational results with experimental data are presented and good agreements between the experiments and predictions are obtained.

  3. Aerodynamics of wings at low Reynolds numbers: Boundary layer separation and reattachment

    NASA Astrophysics Data System (ADS)

    McArthur, John

    Due to advances in electronics technology, it is now possible to build small scale flying and swimming vehicles. These vehicles will have size and velocity scales similar to small birds and fish, and their characteristic Reynolds number will be between 104 and 105. Currently, these flying and swimming vehicles do not perform well, and very little research has been done to characterize them, or to explain why they perform so poorly. This dissertation documents three basic investigations into the performance of small scale lifting surfaces, with Reynolds numbers near 104. Part I. Low Reynolds number aerodynamics. Three airfoil shapes were studied at Reynolds numbers of 1 and 2x104: a flat plate airfoil, a circular arc cambered airfoil, and the Eppler 387 airfoil. Lift and drag force measurements were made on both 2D and 3D conditions, with the 3D wings having an aspect ratio of 6, and the 2D condition being approximated by placing end plates at the wing tips. Comparisons to the limited number of previous measurements show adequate agreement. Previous studies have been inconclusive on whether lifting line theory can be applied to this range of Re, but this study shows that lifting line theory can be applied when there are no sudden changes in the slope of the force curves. This is highly dependent on the airfoil shape of the wing, and explains why previous studies have been inconclusive. Part II. The laminar separation bubble. The Eppler 387 airfoil was studied at two higher Reynolds numbers: 3 and 6x10 4. Previous studies at a Reynolds number of 6x104 had shown this airfoil experiences a drag increase at moderate lift, and a subsequent drag decrease at high lift. Previous studies suggested that the drag increase is caused by a laminar separation bubble, but the experiments used to show this were conducted at higher Reynolds numbers and extrapolated down. Force measurements were combined with flow field measurements at Reynolds numbers 3 and 6x104 to determine whether

  4. Numerical simulation and experimental visualization of the separated cavitating boundary layer over NACA2412

    NASA Astrophysics Data System (ADS)

    Kozák, Jiří; Rudolf, Pavel; Sedlář, Milan; Habán, Vladimír; Hudec, Martin; Huzlík, Rostislav

    2015-05-01

    Cavitation is physical phenomenon of crucial impact on the operation range and service lifetime of the hydraulic machines (pumps, turbines, valves etc.). Experimental measurement of cavitation is expensive and time consuming process, while some important characteristic of the flow are difficult to measure due to the nature of the phenomenon. Current possibilities of computational fluid dynamics provide a way for deeper understanding of cavitation which is important for many applications in the hydraulic machines industry such as expanding operation range or extending lifetime of the hydraulic machines. Simplified model consists of NACA 2412 hydrofoil with 8 degrees angle of attack fixed in between the walls of cavitation tunnel. Present investigation focuses on comparison of vapor volume fractions obtained by 3D CFD simulations and high speed visualization of the real cavitation phenomena. Several operating regimes corresponding to different cavitation numbers are studied with aim to assess the dynamics of the separated cavitating sheets/clouds

  5. Experimental and analytical study of a conically diffused flow with a nearly separated boundary layer

    NASA Technical Reports Server (NTRS)

    Boldman, D. R.; Neumann, H. E.

    1973-01-01

    Turbulence measurements were obtained in the nearly separated flow in a 13 deg total angle of divergence conical diffuser coupled to a constant area tailpipe. Air at 207 newtons per square centimeter and 308 K provided an inlet velocity of about 51 meters per second at an inlet unit Reynolds number of 63.7 million per meter. Very high longitudinal turbulence intensities accompanied the diffusion process with peak values approaching 40 percent when normalized by the local centerline velocity. Predictions of the pressure recovery coefficient using a mixing length concept were good in the early stages of diffusion. In the latter stages of diffusion satisfactory predictions of the pressure recovery were obtained with an empirical method.

  6. In-line real time air monitor

    DOEpatents

    Wise, M.B.; Thompson, C.V.

    1998-07-14

    An in-line gas monitor capable of accurate gas composition analysis in a continuous real time manner even under strong applied vacuum conditions operates by mixing an air sample with helium forming a sample gas in two complementary sample loops embedded in a manifold which includes two pairs of 3-way solenoid valves. The sample gas is then analyzed in an ion trap mass spectrometer on a continuous basis. Two valve drivers actuate the two pairs of 3-way valves in a reciprocating fashion, so that there is always flow through the in-line gas monitor via one or the other of the sample loops. The duty cycle for the two pairs of 3-way valves is varied by tuning the two valve drivers to a duty cycle typically between 0.2 to 0.7 seconds. 3 figs.

  7. In-line real time air monitor

    DOEpatents

    Wise, Marcus B.; Thompson, Cyril V.

    1998-01-01

    An in-line gas monitor capable of accurate gas composition analysis in a continuous real time manner even under strong applied vacuum conditions operates by mixing an air sample with helium forming a sample gas in two complementary sample loops embedded in a manifold which includes two pairs of 3-way solenoid valves. The sample gas is then analyzed in an ion trap mass spectrometer on a continuous basis. Two valve drivers actuate the two pairs of 3-way valves in a reciprocating fashion, so that there is always flow through the in-line gas monitor via one or the other of the sample loops. The duty cycle for the two pairs of 3-way valves is varied by tuning the two valve drivers to a duty cycle typically between 0.2 to 0.7 seconds.

  8. Efficient instruction sequencing with Inline Target Insertion

    NASA Technical Reports Server (NTRS)

    Hwu, Wen-Mei W.; Chang, Pohua P.

    1992-01-01

    Inline target insertion, a specific compiler and pipeline implementation method for delayed branches with squashing, is defined. The method is shown to offer two important features not discovered in previous studies. First, branches inserted into branch slots are correctly executed. Second, the execution returns correctly from interrupts or exceptions with only one program counter. These two features result in better performance and less software/hardware complexity than conventional delayed branching mechanisms.

  9. Flowing atmospheric pressure afterglow combined with laser ablation for direct analysis of compounds separated by thin-layer chromatography.

    PubMed

    Cegłowski, Michał; Smoluch, Marek; Reszke, Edward; Silberring, Jerzy; Schroeder, Grzegorz

    2016-01-01

    A thin-layer chromatography-mass spectrometry (TLC-MS) setup for characterization of low molecular weight compounds separated on standard TLC plates has been constructed. This new approach successfully combines TLC separation, laser ablation, and ionization using flowing atmospheric pressure afterglow (FAPA) source. For the laser ablation, a low-priced 445-nm continuous-wave diode laser pointer, with a power of 1 W, was used. The combination of the simple, low-budget laser pointer and the FAPA ion source has made this experimental arrangement broadly available, also for small laboratories. The approach was successfully applied for the characterization of low molecular weight compounds separated on TLC plates, such as a mixture of pyrazole derivatives, alkaloids (nicotine and sparteine), and an extract from a drug tablet consisting of paracetamol, propyphenazone, and caffeine. The laser pointer used was capable of ablating organic compounds without the need of application of any additional substances (matrices, staining, etc.) on the TLC spots. The detection limit of the proposed method was estimated to be 35 ng/cm(2) of a pyrazole derivative. PMID:26563110

  10. Control of boundary layer separation and the wake of an airfoil using ns-DBD plasma actuators

    NASA Astrophysics Data System (ADS)

    Ashcraft, Timothy

    The efficacy of nanosecond pulse driven dielectric barrier discharge (ns-DBD) plasma actuators for boundary layer separation and wake control is investigated experimentally. A single ns-DBD plasma actuator is placed at the leading edge of a NACA 0012 airfoil model. Both baseline and controlled flow fields are studied using static pressure measurements, Particle Image Velocimetry (PIV) and Constant Temperature Anemometry (CTA). Experiments are primarily performed at Re = 0.74 x 106 and alpha = 18°. CP, PIV and CTA data show that a forcing frequency of F+ = 1.14 is optimal for separation control. CTA surveys of the wake at x/c = 7 indicate three approximate regimes of behavior. Forcing in the range 0.92< F+ < 1.52 results in the best conditions for separation control over the airfoil, but has no dominant signature in the wake at x/c = 7. Excitation in the range of 0.23 < F+ < 0.92 produces a single dominant frequency in the wake while F+ < 0.23 shows behavior representing a possible impulse response or nonlinear effects. PIV data confirm these observations in all three regimes. Cross-correlations of CTA data are also employed to evaluate the two-dimensionality of the excited wake. The initial results presented here are part of an ongoing effort to use active flow control (AFC), in the form of ns-DBDs, as an enabling technology for the study of unsteady aerodynamics and vortex-body interactions.

  11. Characteristics of a separating confluent boundary layer and the downstream wake

    NASA Technical Reports Server (NTRS)

    Adair, Desmond; Horne, W. Clifton

    1987-01-01

    Measurements of pressure and velocity characteristics are presented and analyzed for flow over and downstream of a NACA 4412 airfoil equipped with a NACA 4415 single-slotted flap at high angle of attack and close to maximum lift. The flow remained attached over the main element while a large region of recirculating flow occurred over the aft 61 percent of the flap. The airfoil configuration was tested at a Mach number of 0.09 and a chord Reynolds number of 1.8x10 to the 6th power in the NASA Ames Research Center 7- by 10-Foot Wind Tunnel. Measurement of mean and fluctuation velocities were obtained in regions of recirculation and high turbulence intensity using 3-D laser velocimetry. In regions where the flow had a preferred direction and relatively low turbulence intensity, hot-wire anemometry was used. Emphasis was placed on obtaining characteristics in the confluent boundary layer, the region of recirculating flow, and in the downstream wake. Surface pressure measurements were made on the main airfoil, flap, wind tunnel roof and floor. It is thought likely that because the model is large when compared to the wind tunnel cross section, the wind tunnel floor and ceiling interference should be taken into account when the flow field is calculated.

  12. Characteristics of a separating confluent boundary layer and the downstream wake

    NASA Astrophysics Data System (ADS)

    Adair, Desmond; Horne, W. Clifton

    1987-12-01

    Measurements of pressure and velocity characteristics are presented and analyzed for flow over and downstream of a NACA 4412 airfoil equipped with a NACA 4415 single-slotted flap at high angle of attack and close to maximum lift. The flow remained attached over the main element while a large region of recirculating flow occurred over the aft 61 percent of the flap. The airfoil configuration was tested at a Mach number of 0.09 and a chord Reynolds number of 1.8x10 to the 6th power in the NASA Ames Research Center 7- by 10-Foot Wind Tunnel. Measurement of mean and fluctuation velocities were obtained in regions of recirculation and high turbulence intensity using 3-D laser velocimetry. In regions where the flow had a preferred direction and relatively low turbulence intensity, hot-wire anemometry was used. Emphasis was placed on obtaining characteristics in the confluent boundary layer, the region of recirculating flow, and in the downstream wake. Surface pressure measurements were made on the main airfoil, flap, wind tunnel roof and floor. It is thought likely that because the model is large when compared to the wind tunnel cross section, the wind tunnel floor and ceiling interference should be taken into account when the flow field is calculated.

  13. Ion Exchange and Thin Layer Chromatographic Separation and Identification of Amino Acids in a Mixture: An Experiment for General Chemistry and Biotechnology Laboratories

    ERIC Educational Resources Information Center

    Brunauer, Linda S.; Caslavka, Katelyn E.; Van Groningen, Karinne

    2014-01-01

    A multiday laboratory exercise is described that is suitable for first-year undergraduate chemistry, biochemistry, or biotechnology students. Students gain experience in performing chromatographic separations of biomolecules, in both a column and thin layer chromatography (TLC) format. Students chromatographically separate amino acids (AA) in an…

  14. The effects of upstream mass injection by vortex generator jets on shock-induced turbulent boundary layer separation

    NASA Astrophysics Data System (ADS)

    Bueno, Pablo Cesar

    An experimental study was conducted to investigate the effects of upstream mass injection, by means of vortex generator jets (VGJs), on the shock wave/turbulent boundary layer interaction (SWTBLI) generated by cylinder in a Mach 2 flow. The objectives of the study were: (i) to characterize the changes to the global structure of the flowfield introduced by the VGJs, and (ii) to study how the injection affected the dynamics of the separation shock foot. The injection was provided by three high-speed valves, placed across the span of the test section, which generated underexpanded jets. Two jet orientations were studied: normal to the wall, and pitched at 60° and skewed at 90° with respect to the freestream. In addition, the effects of both continuous and pulsed injection were investigated. Velocity measurements of the upstream boundary layer, VGJs, and -shock system were made using a wide-field particle image velocimetry (PIV) system, and an array of fast-response pressure transducers was used to monitor the wall pressure under the intermittent region of the interaction. The velocity measurements of the baseline case captured nearly all the relevant flow structures including the -shock and primary and secondary vortices. However, neither mean supersonic reversed flow nor the supersonic jet that presumably exists downstream of the triple point were observed. When injection was applied, the scale of the separated flow changed considerably. For normal injection, the primary vortex was nearly suppressed, while for pitched/skewed injection, the secondary vortex increased in size. Mean streamwise and transverse velocity profiles upstream of the separation shock showed that, for both jet orientations, the VGJs caused the flow in the boundary layer to accelerate. However, for normal injection, the acceleration did not extend down to the wall. Phase-averaged velocity measurements of the opening phase of the valves indicated that there is a phase lag between the jets and the

  15. Investigation of blown boundary layers with an improved wall jet system. Ph.D. Thesis. Final Technical Report, 1 Jul. 1978 - Dec. 1979; [to prevent turbulent boundary layer separation

    NASA Technical Reports Server (NTRS)

    Saripalli, K. R.; Simpson, R. L.

    1979-01-01

    The behavior of two dimensional incompressible turbulent wall jets submerged in a boundary layer when they are used to prevent boundary layer separation on plane surfaces is investigated. The experimental set-up and instrumentation are described. Experimental results of zero pressure gradient flow and adverse pressure gradient flow are presented. Conclusions are given and discussed.

  16. Separation of Berberine Hydrochloride and Tetrahydropalmatine and Their Quantitative Analysis with Thin Layer Chromatography Involved with Ionic Liquids

    PubMed Central

    Lu, Jing; Ma, Hong-yan; Zhang, Wei; Ma, Zhi-guo; Yao, Shun

    2015-01-01

    [BMIM]OH was used in mobile and stationary phase of thin layer chromatography (TLC) to analyze berberine hydrochloride and tetrahydropalmatine for the first time. Supported imidazole ionic liquid with hydroxide ion on silica gel (SiO2·Im+·OH−) was synthesized through simple procedure and characterized by Fourier transform infrared spectroscopy (FT-IR), elemental analysis, and scanning electron microscope (SEM). Moreover, on the plates prepared by SiO2·Im+·OH−, the contents of the above alkaloids in the Chinese patent medicine (CPM) of “Stomacheasy” capsule were successfully determined by TLC scanner. The key conditions and chromatographic behaviors were also investigated in detail. According to similar ways, ionic liquids (ILs) also can be used in other planar chromatographies in two modes. This study is expected to be helpful in expanding the application of IL and its bonded silica gel in TLC separation field. PMID:26609463

  17. An experimental and numerical investigation of shock-wave induced turbulent boundary-layer separation at hypersonic speeds

    NASA Technical Reports Server (NTRS)

    Marvin, J. G.; Horstman, C. C.; Rubesin, M. W.; Coakley, T. J.; Kussoy, M. I.

    1975-01-01

    An experiment designed to test and guide computations of the interaction of an impinging shock wave with a turbulent boundary layer is described. Detailed mean flow-field and surface data are presented for two shock strengths which resulted in attached and separated flows, respectively. Numerical computations, employing the complete time-averaged Navier-Stokes equations along with algebraic eddy-viscosity and turbulent Prandtl number models to describe shear stress and heat flux, are used to illustrate the dependence of the computations on the particulars of the turbulence models. Models appropriate for zero-pressure-gradient flows predicted the overall features of the flow fields, but were deficient in predicting many of the details of the interaction regions. Improvements to the turbulence model parameters were sought through a combination of detailed data analysis and computer simulations which tested the sensitivity of the solutions to model parameter changes. Computer simulations using these improvements are presented and discussed.

  18. Intermittent Behavior of the Separated Boundary Layer along the Suction Surface of a Low Pressure Turbine Blade under Periodic Unsteady Flow Conditions

    NASA Technical Reports Server (NTRS)

    Oeztuerk, B; Schobeiri, M. T.; Ashpis, David E.

    2005-01-01

    The paper experimentally and theoretically studies the effects of periodic unsteady wake flow and aerodynamic characteristics on boundary layer development, separation and re-attachment along the suction surface of a low pressure turbine blade. The experiments were carried out at Reynolds number of 110,000 (based on suction surface length and exit velocity). For one steady and two different unsteady inlet flow conditions with the corresponding passing frequencies, intermittency behaviors were experimentally and theoretically investigated. The current investigation attempts to extend the intermittency unsteady boundary layer transition model developed in previously to the LPT cases, where separation occurs on the suction surface at a low Reynolds number. The results of the unsteady boundary layer measurements and the intermittency analysis were presented in the ensemble-averaged and contour plot forms. The analysis of the boundary layer experimental data with the flow separation, confirms the universal character of the relative intermittency function which is described by a Gausssian function.

  19. Effect of Permeate Drag Force on the Development of a Biofouling Layer in a Pressure-Driven Membrane Separation System▿

    PubMed Central

    Eshed, L.; Yaron, S.; Dosoretz, C. G.

    2008-01-01

    The effect of permeate flux on the development of a biofouling layer on cross-flow separation membranes was studied by using a bench-scale system consisting of two replicate 100-molecular-weight-cutoff tubular ultrafiltration membrane modules, one that allowed flow of permeate and one that did not (control). The system was inoculated with Pseudomonas putida S-12 tagged with a red fluorescent protein and was operated using a laminar flow regimen under sterile conditions with a constant feed of diluted (1:75) Luria-Bertani medium. Biofilm development was studied by using field emission scanning electron microscopy and confocal scanning laser microscopy and was subsequently quantified by image analysis, as well as by determining live counts and by permeate flux monitoring. Biofilm development was highly enhanced in the presence of permeate flow, which resulted in the buildup of complex three-dimensional structures on the membrane. Bacterial transport toward the membrane by permeate drag was found to be a mechanism by which cross-flow filtration contributes to the buildup of a biofouling layer that was more dominant than transport of nutrients. Cellular viability was found to be not essential for transport and adhesion under cross-flow conditions, since the permeate drag overcame the effect of bacterial motility. PMID:18931284

  20. Time-averaged in-line digital holographic interferometry for vibration analysis

    SciTech Connect

    Asundi, Anand; Singh, Vijay Raj

    2006-04-10

    Time-averaged in-line digital holography is applied for vibration analysis. In particular, by use of a double-exposure approach, simultaneous determination of vibration mode shape and mean static state deformation during a vibration cycle are obtained. The subtraction of two numerically reconstructed digital holograms recorded at the same resonant frequency but with a small difference in amplitude shows the mixing of Bessel-type time-averaged fringes owing to vibration and of the double-exposure fringes owing to differences in the mean deformation of the object. It is shown that separation of these fringe patterns can be readily accomplished numerically. An experimental demonstration of this effect by use of in-line digital holography for relatively small membranes is demonstrated.

  1. Effect of a thin ceramic-coating layer on thermal and electrochemical properties of polyethylene separator for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Shi, Chuan; Zhang, Peng; Chen, Lixiao; Yang, Pingting; Zhao, Jinbao

    2014-12-01

    In this paper, a new kind of ceramic-coating separator for lithium-ion batteries is successfully prepared by forming a ceramic layer consisted of Al2O3 powder, carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) mix binder onto one side of pristine PE separator. During the preparation of the separator, water is used as solvent and a very small amount of SBR-CMC mixture is applied as binder to obtain better thermal stability. The effect of thickness of the ceramic-coating layer on its thermal stability, physical properties and electrochemical performance is also investigated. The results clearly showed that the ceramic-coating separator with SBR-CMC binder has wonderful thermal stability, good wettability and high uptake of liquid electrolyte. Pouch cell tests with the ceramic-coating separator also show excellent stable cycle performance.

  2. Particle Image Velocimetry Measurements of a Two/Three-dimensional Separating/Reattaching Boundary Layer Downstream of an Axisymmetric Backward-facing Step

    NASA Technical Reports Server (NTRS)

    Hudy, Laura M.; Naguib, Ahmed M.; Humphreys, William M.; Bartram, Scott M.

    2005-01-01

    Planar Particle Image Velocimetry measurements were obtained in the separating/reattaching flow region downstream of an axisymmetric backward-facing step. Data were acquired for a two-dimensional (2D) separating boundary layer at five different Reynolds numbers based on step height (Re(sub h)), spanning 5900-33000, and for a three-dimensional (3D) separating boundary layer at Re(sub h) = 5980 and 8081. Reynolds number effects were investigated in the 2D cases using mean-velocity field, streamwise and wall-normal turbulent velocity, and Reynolds stress statistics. Results show that both the reattachment length (x(sub r)) and the secondary separation point are Reynolds number dependent. The reattachment length increased with rising Re(sub h) while the secondary recirculation region decreased in size. These and other Re(sub h) effects were interpreted in terms of changes in the separating boundary layer thickness and wall-shear stress. On the other hand, in the 3D case, it was found that the imposed cross-flow component was relatively weak in comparison to the streamwise component. As a result, the primary influences of three dimensionality only affected the near-separation region rather than the entire separation bubble.

  3. A general integral form of the boundary-layer equation for incompressible flow with an application to the calculation of the separation point of turbulent boundary layers

    NASA Technical Reports Server (NTRS)

    Tetervin, Neal; Lin, Chia Chiao

    1951-01-01

    A general integral form of the boundary-layer equation, valid for either laminar or turbulent incompressible boundary-layer flow, is derived. By using the experimental finding that all velocity profiles of the turbulent boundary layer form essentially a single-parameter family, the general equation is changed to an equation for the space rate of change of the velocity-profile shape parameter. The lack of precise knowledge concerning the surface shear and the distribution of the shearing stress across turbulent boundary layers prevented the attainment of a reliable method for calculating the behavior of turbulent boundary layers.

  4. Single-layer centrifugation separates spermatozoa from diploid cells in epididymal samples from gray wolves, Canis lupus (L.).

    PubMed

    Muñoz-Fuentes, Violeta; Linde Forsberg, Catharina; Vilà, Carles; Morrell, Jane M

    2014-09-15

    Sperm samples may be used for assisted reproductive technologies (e.g., farmed or endangered species) or as a source of haploid DNA or sperm-specific RNA. When ejaculated spermatozoa are not available or are very difficult to obtain, as is the case for most wild endangered species, the epididymides of dead animals (e.g., animals that have been found dead, shot by hunters or poachers, or that that require euthanasia in zoological collections) can be used as a source of sperm. Such epididymal sperm samples are usually contaminated with cellular debris, erythrocytes, leukocytes, and sometimes also bacteria. These contaminants may be sources of reactive oxygen species that damage spermatozoa during freezing or contribute undesired genetic material from diploid cells. We used single-layer centrifugation through a colloid formulation, Androcoll-C, to successfully separate wolf epididymal spermatozoa from contaminating cells and cellular debris in epididymal samples harvested from carcasses. Such a procedure may potentially be applied to epididymal sperm samples from other species. PMID:25028195

  5. Separating semiconductor devices from substrate by etching graded composition release layer disposed between semiconductor devices and substrate including forming protuberances that reduce stiction

    SciTech Connect

    Tauke-Pedretti, Anna; Nielson, Gregory N; Cederberg, Jeffrey G; Cruz-Campa, Jose Luis

    2015-05-12

    A method includes etching a release layer that is coupled between a plurality of semiconductor devices and a substrate with an etch. The etching includes etching the release layer between the semiconductor devices and the substrate until the semiconductor devices are at least substantially released from the substrate. The etching also includes etching a protuberance in the release layer between each of the semiconductor devices and the substrate. The etch is stopped while the protuberances remain between each of the semiconductor devices and the substrate. The method also includes separating the semiconductor devices from the substrate. Other methods and apparatus are also disclosed.

  6. Raytheon's next generation compact inline cryocooler architecture

    SciTech Connect

    Schaefer, B. R.; Bellis, L.; Ellis, M. J.; Conrad, T.

    2014-01-29

    Since the 1970s, Raytheon has developed, built, tested and integrated high performance cryocoolers. Our versatile designs for single and multi-stage cryocoolers provide reliable operation for temperatures from 10 to 200 Kelvin with power levels ranging from 50 W to nearly 600 W. These advanced cryocoolers incorporate clearance seals, flexure suspensions, hermetic housings and dynamic balancing to provide long service life and reliable operation in all relevant environments. Today, sensors face a multitude of cryocooler integration challenges such as exported disturbance, efficiency, scalability, maturity, and cost. As a result, cryocooler selection is application dependent, oftentimes requiring extensive trade studies to determine the most suitable architecture. To optimally meet the needs of next generation passive IR sensors, the Compact Inline Raytheon Stirling 1-Stage (CI-RS1), Compact Inline Raytheon Single Stage Pulse Tube (CI-RP1) and Compact Inline Raytheon Hybrid Stirling/Pulse Tube 2-Stage (CI-RSP2) cryocoolers are being developed to satisfy this suite of requirements. This lightweight, compact, efficient, low vibration cryocooler combines proven 1-stage (RS1 or RP1) and 2-stage (RSP2) cold-head architectures with an inventive set of warm-end mechanisms into a single cooler module, allowing the moving mechanisms for the compressor and the Stirling displacer to be consolidated onto a common axis and in a common working volume. The CI cryocooler is a significant departure from the current Stirling cryocoolers in which the compressor mechanisms are remote from the Stirling displacer mechanism. Placing all of the mechanisms in a single volume and on a single axis provides benefits in terms of package size (30% reduction), mass (30% reduction), thermodynamic efficiency (>20% improvement) and exported vibration performance (≤25 mN peak in all three orthogonal axes at frequencies from 1 to 500 Hz). The main benefit of axial symmetry is that proven balancing

  7. Raytheon's next generation compact inline cryocooler architecture

    NASA Astrophysics Data System (ADS)

    Schaefer, B. R.; Bellis, L.; Ellis, M. J.; Conrad, T.

    2014-01-01

    Since the 1970s, Raytheon has developed, built, tested and integrated high performance cryocoolers. Our versatile designs for single and multi-stage cryocoolers provide reliable operation for temperatures from 10 to 200 Kelvin with power levels ranging from 50 W to nearly 600 W. These advanced cryocoolers incorporate clearance seals, flexure suspensions, hermetic housings and dynamic balancing to provide long service life and reliable operation in all relevant environments. Today, sensors face a multitude of cryocooler integration challenges such as exported disturbance, efficiency, scalability, maturity, and cost. As a result, cryocooler selection is application dependent, oftentimes requiring extensive trade studies to determine the most suitable architecture. To optimally meet the needs of next generation passive IR sensors, the Compact Inline Raytheon Stirling 1-Stage (CI-RS1), Compact Inline Raytheon Single Stage Pulse Tube (CI-RP1) and Compact Inline Raytheon Hybrid Stirling/Pulse Tube 2-Stage (CI-RSP2) cryocoolers are being developed to satisfy this suite of requirements. This lightweight, compact, efficient, low vibration cryocooler combines proven 1-stage (RS1 or RP1) and 2-stage (RSP2) cold-head architectures with an inventive set of warm-end mechanisms into a single cooler module, allowing the moving mechanisms for the compressor and the Stirling displacer to be consolidated onto a common axis and in a common working volume. The CI cryocooler is a significant departure from the current Stirling cryocoolers in which the compressor mechanisms are remote from the Stirling displacer mechanism. Placing all of the mechanisms in a single volume and on a single axis provides benefits in terms of package size (30% reduction), mass (30% reduction), thermodynamic efficiency (>20% improvement) and exported vibration performance (≤25 mN peak in all three orthogonal axes at frequencies from 1 to 500 Hz). The main benefit of axial symmetry is that proven balancing

  8. Inline high frequency ultrasonic particle sizer

    NASA Astrophysics Data System (ADS)

    Lefebvre, F.; Petit, J.; Nassar, G.; Debreyne, P.; Delaplace, G.; Nongaillard, B.

    2013-07-01

    This paper reports the development of a new method of particle sizing in a liquid. This method uses high frequency focused ultrasounds to detect particles crossing the focal zone of an ultrasonic sensor and to determine their size distribution by processing the reflected echoes. The major advantage of this technique compared to optical sizing methods is its ability to measure the size of particles suspended in an opaque liquid without any dedicated sample preparation. Validations of ultrasonic measurements were achieved on suspensions of polymethyl methacrylate beads in a size range extending from a few micrometer to several hundred micrometer with a temporal resolution of 1 s. The inline detection of aggregate formation was also demonstrated.

  9. Continuous inline blending of antimisting kerosene

    NASA Technical Reports Server (NTRS)

    Parikh, P.; Yavrouian, A.; Sarohia, V.

    1985-01-01

    A continuous inline blender was developed to blend polymer slurries with a stream of jet A fuel. The viscosity of the slurries ranged widely. The key element of the blender was a static mixer placed immediately downstream of the slurry injection point. A positive displacement gear pump for jet A was employed, and a progressive cavity rotary screw pump was used for slurry pumping. Turbine flow meters were employed for jet A metering while the slurry flow rate was calibrated against the pressure drop in the injection tube. While using one of the FM-9 variant slurries, a provision was made for a time delay between the addition of slurry and the addition of amine sequentially into the jet A stream.

  10. Raytheon's next generation compact inline cryocooler architecture

    NASA Astrophysics Data System (ADS)

    Schaefer, B. R.; Bellis, L.; Ellis, M. J.; Conrad, T.

    2013-09-01

    Infrared sensors face a multitude of cryocooler integration challenges such as exported disturbance, efficiency, scalability, maturity, and cost. As a result, cryocooler selection has become application dependent, oftentimes requiring extensive trade studies to determine the most suitable architecture. To optimally meet the needs of next generation passive infrared (IR) sensors, the Compact Inline Raytheon Single Stage Pulse Tube (CI-RP1) and Compact Inline Raytheon Hybrid Stirling/Pulse Tube 2-Stage (CI-RSP2) cryocoolers are being developed to satisfy this suite of requirements. This lightweight, compact, efficient, low vibration cryocooler combines proven 1-stage and 2-stage cold-head architectures with an inventive set of warm-end mechanisms into a single mechanical module, allowing the moving mechanisms for the compressor and the Stirling displacer to be consolidated onto a common axis and in a common working volume. The CI cryocooler is a significant departure from the current Stirling cryocoolers in which the compressor mechanisms are remote from the Stirling displacer mechanism. Placing all of the mechanisms in a single volume and on a single axis provides benefits in terms of package size (30% reduction), mass (30% reduction), thermodynamic efficiency (<20% improvement) and exported vibration performance (<=25 mN peak in all three orthogonal axes at frequencies from 1 to 500 Hz). The main benefit of axial symmetry is that proven balancing techniques and hardware can be utilized to null all motion along the common axis. Low vibration translates to better sensor performance resulting in simpler, more direct mechanical mounting configurations, eliminating the need for convoluted, expensive, massive, long lead damping hardware.

  11. Effect of Reynolds Number and Periodic Unsteady Wake Flow Condition on Boundary Layer Development, Separation, and Intermittency Behavior Along the Suction Surface of a Low Pressure Turbine Blade

    NASA Technical Reports Server (NTRS)

    Schobeiri, M. T.; Ozturk, B.; Ashpis, David E.

    2007-01-01

    The paper experimentally studies the effects of periodic unsteady wake flow and different Reynolds numbers on boundary layer development, separation and re-attachment along the suction surface of a low pressure turbine blade. The experimental investigations were performed on a large scale, subsonic unsteady turbine cascade research facility at Turbomachinery Performance and Flow Research Laboratory (TPFL) of Texas A&M University. The experiments were carried out at Reynolds numbers of 110,000 and 150,000 (based on suction surface length and exit velocity). One steady and two different unsteady inlet flow conditions with the corresponding passing frequencies, wake velocities, and turbulence intensities were investigated. The reduced frequencies chosen cover the operating range of LP turbines. In addition to the unsteady boundary layer measurements, surface pressure measurements were performed. The inception, onset, and the extent of the separation bubble information collected from the pressure measurements were compared with the hot wire measurements. The results presented in ensemble-averaged, and the contour plot forms help to understand the physics of the separation phenomenon under periodic unsteady wake flow and different Reynolds number. It was found that the suction surface displayed a strong separation bubble for these three different reduced frequencies. For each condition, the locations defining the separation bubble were determined carefully analyzing and examining the pressure and mean velocity profile data. The location of the boundary layer separation was dependent of the Reynolds number. It is observed that starting point of the separation bubble and the re-attachment point move further downstream by increasing Reynolds number from 110,000 to 150,000. Also, the size of the separation bubble is smaller when compared to that for Re=110,000.

  12. Cobalt Ferrite Bearing Nitrogen-Doped Reduced Graphene Oxide Layers Spatially Separated with Microporous Carbon as Efficient Oxygen Reduction Electrocatalyst.

    PubMed

    Kashyap, Varchaswal; Singh, Santosh K; Kurungot, Sreekumar

    2016-08-17

    The present work discloses how high-quality dispersion of fine particles of cobalt ferrite (CF) could be attained on nitrogen-doped reduced graphene oxide (CF/N-rGO) and how this material in association with a microporous carbon phase could deliver significantly enhanced activity toward electrochemical oxygen reduction reaction (ORR). Our study indicates that the microporous carbon phase plays a critical role in spatially separating the layers of CF/N-rGO and in creating a favorable atmosphere to ensure the seamless distribution of the reactants to the active sites located on CF/N-rGO. In terms of the ORR current density, the heat-treated hybrid catalyst at 150 °C (CF/N-rGO-150) is found to be clearly outperforming (7.4 ± 0.5 mA/cm(2)) the state-of-the-art 20 wt % Pt-supported carbon catalyst (PtC) (5.4 ± 0.5 mA/cm(2)). The mass activity and stability of CF-N-rGO-150 are distinctly superior to PtC even after 5000 electrochemical cycles. As a realistic system level exploration of the catalyst, testing of a primary zinc-air battery could be demonstrated using CF/N-rGO-150 as the cathode catalyst. The battery is giving a galvanostatic discharge time of 15 h at a discharge current density of 20 mA/cm(2) and a specific capacity of ∼630 mAh g(-1) in 6 M KOH by using a Zn foil as the anode. Distinctly, the battery performance of this system is found to be superior to that of PtC in less concentrated KOH solution as the electrolyte. PMID:27464229

  13. Effect of boundary layer thickness before the flow separation on aerodynamic characteristics and heat transfer behind an abrupt expansion in a round tube

    NASA Astrophysics Data System (ADS)

    Terekhov, V. I.; Bogatko, T. V.

    2008-03-01

    Results of numerical investigation of the boundary layer thickness on turbulent separation and heat transfer in a tube with an abrupt expansion are shown. The Menter turbulence model of shear stress transfer implemented in Fluent package was used for calculations. The range of Reynolds numbers was from 5·103 to 105. The air was used as the working fluid. A degree of tube expansion was ( D 2/ D 1)2 = 1.78. A significant effect of thickness of the separated boundary layer both on dynamic and thermal characteristics of the flow is shown. In particular, it was found that with an increase in the boundary layer thickness the recirculation zone increases, and the maximum heat transfer coefficient decreases.

  14. In-line assay monitor for uranium hexafluoride

    DOEpatents

    Wallace, Steven A.

    1981-01-01

    An in-line assay monitor for determining the content of uranium-235 in a uranium hexafluoride gas isotopic separation system is provided which removes the necessity of complete access to the operating parameters of the system for determining the uranium-235 content. The monitor is intended for uses such as safeguard applications to assure that weapons grade uranium is not being produced in an enrichment cascade. The method and monitor for carrying out the method involve cooling of a radiation pervious chamber connected in fluid communication with the selected point in the system to withdraw a specimen and solidify the specimen in the chamber. The specimen is irradiated by means of an ionizing radiation source of energy different from that of the 185 keV gamma emissions from the uranium-235 present in the specimen. Simultaneously, the gamma emissions from the uranium-235 of the specimen and the source emissions transmitted through the sample are counted and stored in a multiple channel analyzer. The uranium-235 content of the specimen is determined from the comparison of the accumulated 185 keV energy counts and the reference energy counts. The latter is used to measure the total uranium isotopic content of the specimen. The process eliminates the necessity of knowing the system operating conditions and yet obtains the necessary data without need for large scintillation crystals and sophisticated mechanical designs.

  15. 49. View of unlined canal near inline stream gaging station, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. View of unlined canal near in-line stream gaging station, looking west. Photo by Robin Lee Tedder, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  16. A new wavelet-based reconstruction algorithm for twin image removal in digital in-line holography

    NASA Astrophysics Data System (ADS)

    Hattay, Jamel; Belaid, Samir; Aguili, Taoufik; Lebrun, Denis

    2016-07-01

    Two original methods are proposed here for digital in-line hologram processing. Firstly, we propose an entropy-based method to retrieve the focus plane which is very useful for digital hologram reconstruction. Secondly, we introduce a new approach to remove the so-called twin images reconstructed by holograms. This is achieved owing to the Blind Source Separation (BSS) technique. The proposed method is made up of two steps: an Adaptive Quincunx Lifting Scheme (AQLS) and a statistical unmixing algorithm. The AQLS tool is based on wavelet packet transform, whose role is to maximize the sparseness of the input holograms. The unmixing algorithm uses the Independent Component Analysis (ICA) tool. Experimental results confirm the ability of convolutive blind source separation to discard the unwanted twin image from in-line digital holograms.

  17. In-line inspection method with AIT-II and ADC

    NASA Astrophysics Data System (ADS)

    Terryll, Kathleen; Mateos, Carlos

    2001-04-01

    In this article, we emphasize the streamlined, in-line inspection methodology at Agere Systems, Madrid, Spain (formally Lucent Technologies, Microelectronics). This method includes the use of AIT-II with Impact ADC 2.0 to better focus and separate out excursion and baseline events. Real life examples demonstrating the potential of ADC are presented. In continuation, the shop reaction methodology and data flow scheme is described in detail. Currently, the Agere systems methodology is one of the most advanced in the European semiconductor industry.

  18. Optimization of parameters for the inline-injection system at Brookhaven Accelerator Test Facility

    SciTech Connect

    Parsa, Z.; Ko, S.K.

    1995-10-01

    We present some of our parameter optimization results utilizing code PARMLEA, for the ATF Inline-Injection System. The new solenoid-Gun-Solenoid -- Drift-Linac Scheme would improve the beam quality needed for FEL and other experiments at ATF as compared to the beam quality of the original design injection system. To optimize the gain in the beam quality we have considered various parameters including the accelerating field gradient on the photoathode, the Solenoid field strengths, separation between the gun and entrance to the linac as well as the (type size) initial charge distributions. The effect of the changes in the parameters on the beam emittance is also given.

  19. Tailoring the Separation Behavior of Polymer-Supported Organosilica Layered-Hybrid Membranes via Facile Post-Treatment Using HCl and HN3 Vapors.

    PubMed

    Gong, Genghao; Nagasawa, Hiroki; Kanezashi, Masakoto; Tsuru, Toshinori

    2016-05-01

    A promising layered-hybrid membrane consisting of a microporous organosilica active layer deposited onto a porous polymer support was prepared via a facile sol-gel spin-coating process. Subsequently, the pore sizes and structures of the organosilica top layers on the membrane surface were tuned at mild temperature combined with vapor treatment from either hydrochloric acid (HVT) or ammonia (AVT), thereby tailoring the desalination performance of the membranes during reverse osmosis (RO) processing. The effects of HVT and AVT on the pore size, structure, and morphology of organosilica layers and on the separation performances of membranes were investigated in detail. We confirmed that both HVT and AVT processes accelerated the condensation of silanol (Si-OH) in the organosilica layer, which led to dense silica networks. The layered-hybrid membranes after HVT showed an improved salt rejection and reduced water flux, while membranes after AVT exhibited a decrease in both salt rejection and water permeability. We found that HVT gave rise to smoother and denser organosilica layers, while AVT produced large voids and formed pinholes due to Ostwald ripening. These conclusions were supported by a comparative analysis of the results obtained via FTIR, TG-MS, SPM, and RO desalination. PMID:27070105

  20. Lagrangian transport characteristics of a class of three-dimensional inline-mixing flows with fluid inertia

    SciTech Connect

    Speetjens, M. F. M.; Demissie, E. A.; Metcalfe, G.; Clercx, H. J. H.

    2014-11-15

    Laminar mixing by the inline-mixing principle is a key to many industrial fluids-engineering systems of size extending from micrometers to meters. However, insight into fundamental transport phenomena particularly under the realistic conditions of three-dimensionality (3D) and fluid inertia remains limited. This study addresses these issues for inline mixers with cylindrical geometries and adopts the Rotated Arc Mixer (RAM) as a representative system. Transport is investigated from a Lagrangian perspective by identifying and examining coherent structures that form in the 3D streamline portrait. 3D effects and fluid inertia introduce three key features that are not found in simplified configurations: transition zones between consecutive mixing cells of the inline-mixing flow; local upstream flow (in certain parameter regimes); transition/inertia-induced breaking of symmetries in the Lagrangian equations of motion (causing topological changes in coherent structures). Topological considerations strongly suggest that there nonetheless always exists a net throughflow region between inlet and outlet of the inline-mixing flow that is strictly separated from possible internal regions. The Lagrangian dynamics in this region admits representation by a 2D time-periodic Hamiltonian system. This establishes one fundamental kinematic structure for the present class of inline-mixing flows and implies universal behavior in that all states follow from the Hamiltonian breakdown of one common integrable state. A so-called period-doubling bifurcation is the only way to eliminate transport barriers originating from this state and thus is a necessary (yet not sufficient) condition for global chaos. Important in a practical context is that a common simplification in literature, i.e., cell-wise fully-developed Stokes flow (“2.5D approach”), retains these fundamental kinematic properties and deviates from the generic 3D inertial case only in a quantitative sense. This substantiates its

  1. High Reynolds number tests of a C-141A aircraft semispan model to investigate shock-induced separation. [boundary layer separation

    NASA Technical Reports Server (NTRS)

    Blackerby, W. T.; Cahill, J. F.

    1975-01-01

    Results from a high Reynolds number transonic wind tunnel investigation are presented. Wing chordwise pressure distributions were measured over a matrix of Mach numbers and angles-of-attack for which shock-induced separations are known to exist. The range of Reynolds number covered by these data nearly spanned the gap between previously available wind tunnel and flight test data. The results are compared with both flight and low Reynolds number data, and show that use of the semispan test technique produced good correlation with the prior data at both ends of the Reynolds number range, but indicated strong sensitivity to details of the test setup.

  2. Use of separate ZnTe interface layers to form ohmic contacts to p-CdTe films

    DOEpatents

    Gessert, T.A.

    1999-06-01

    A method of is disclosed improving electrical contact to a thin film of a p-type tellurium-containing II-VI semiconductor comprising: depositing a first undoped layer of ZnTe on a thin film of p-type tellurium containing II-VI semiconductor with material properties selected to limit the formation of potential barriers at the interface between the p-CdTe and the undoped layer, to a thickness sufficient to control diffusion of the metallic-doped ZnTe into the p-type tellurium-containing II-VI semiconductor, but thin enough to minimize affects of series resistance; depositing a second heavy doped p-type ZnTe layer to the first layer using an appropriate dopant; and depositing an appropriate metal onto the outer-most surface of the doped ZnTe layer for connecting an external electrical conductor to an ohmic contact. 11 figs.

  3. Use of separate ZnTe interface layers to form OHMIC contacts to p-CdTe films

    DOEpatents

    Gessert, Timothy A.

    1999-01-01

    A method of improving electrical contact to a thin film of a p-type tellurium-containing II-VI semiconductor comprising: depositing a first undoped layer of ZnTe on a thin film of p-type tellurium containing II-VI semiconductor with material properties selected to limit the formation of potential barriers at the interface between the p-CdTe and the undoped layer, to a thickness sufficient to control diffusion of the metallic-doped ZnTe into the p-type tellurim-containing II-VI semiconductor, but thin enough to minimize affects of series resistance; depositing a second heavy doped p-type ZnTe layer to the first layer using an appropriate dopant; and depositing an appropriate metal onto the outer-most surface of the doped ZnTe layer for connecting an external electrical conductor to an ohmic contact.

  4. Separate and combined effects of static stability and shear variation on the baroclinic instability of a two-layer current

    NASA Technical Reports Server (NTRS)

    Hyun, J. M.

    1981-01-01

    Quasi-geostrophic disturbance instability characteristics are studied in light of a linearized, two-layer Eady model in which both the static stability and the zonal current shear are uniform but different in each layer. It is shown that the qualitative character of the instability is determined by the sign of the basic-state potential vorticity gradient at the layer interface, and that there is a qualitative similarity between the effects of Richardson number variations due to changes in static stability and those due to changes in shear. The two-layer model is also used to construct an analog of the Williams (1974) continuous model of generalized Eady waves, the basic state in that case having zero potential vorticity gradient in the interior. The model results are in good agreement with the earlier Williams findings.

  5. Effects of the energy-separation filter on the performance of each detector layer in the sandwich detector for single-shot dual-energy imaging

    NASA Astrophysics Data System (ADS)

    Kim, J.; Kim, D. W.; Kam, S.; Park, E.; Youn, H.; Kim, H. K.

    2016-02-01

    A novel sandwich-style single-shot detector has been built by stacking two indirect-conversion flat-panel detectors for preclinical dual-energy mouse imaging. Although this single-shot method is more immune to motion artifacts compared with the conventional dual-shot method (i.e., fast kVp switching), it may suffer from reduced image quality because of poor spectral separation between the two detectors. Spectral separation can be improved by using an intermediate filter between the two detector layers. Adversely, the filter reduces the number of x-ray photons reaching the rear detector, hence probably increasing image noise. For a better design and practical use of the sandwich detector for single-shot dual-energy imaging, imaging performances of each detector layer in the sandwich detector are investigated for various spectral-separation extents and applied tube voltages. The imaging performances include the modulation-transfer function, the Wiener noise-power spectrum, and the detective quantum efficiency. According to the experimental results, impacts of the intermediate filter on the imaging performances of each detector layer are marginal. The detailed experimental results are shown in this study.

  6. STC-SAB program users manual for the turbulent boundary layer and turbulent separation prediction methods employed in the NASA Langley streamtube curvature computer program

    NASA Technical Reports Server (NTRS)

    Ferguson, D. R.

    1972-01-01

    The streamtube curvature program (STC) has been developed to predict the inviscid flow field and the pressure distribution about nacelles at transonic speeds. The effects of boundary layer are to displace the inviscid flow and effectively change the body shape. Thus, the body shape must be corrected by the displacement thickness in order to calculate the correct pressure distribution. This report describes the coupling of the Stratford and Beavers boundary layer solution with the inviscid STC analysis so that all nacelle pressure forces, friction drag, and incipient separation may be predicted. The usage of the coupled STC-SAB computer program is outlined and the program input and output are defined. Included in this manual are descriptions of the principal boundary layer tables and other revisions to the STC program. The use of the viscous option is controlled by the engineer during program input definition.

  7. Feasibility of correlating separation of ternary mixtures of neutral analytes via thin layer chromatography with supercritical fluid chromatography in support of green flash separations.

    PubMed

    Ashraf-Khorassani, M; Yan, Q; Akin, A; Riley, F; Aurigemma, C; Taylor, L T

    2015-10-30

    Method development for normal phase flash liquid chromatography traditionally employs preliminary screening using thin layer chromatography (TLC) with conventional solvents on bare silica. Extension to green flash chromatography via correlation of TLC migration results, with conventional polar/nonpolar liquid mixtures, and packed column supercritical fluid chromatography (SFC) retention times, via gradient elution on bare silica with a suite of carbon dioxide mobile phase modifiers, is reported. Feasibility of TLC/SFC correlation is individually described for eight ternary mixtures for a total of 24 neutral analytes. The experimental criteria for TLC/SFC correlation was assumed to be as follows: SFC/UV/MS retention (tR) increases among each of the three resolved mixture components; while, TLC migration (Rf) decreases among the same resolved mixture components. Successful correlation of TLC to SFC was observed for most of the polar organic solvents tested, with the best results observed via SFC on bare silica with methanol as the CO2 modifier and TLC on bare silica with a methanol/dichloromethane mixture. PMID:26422305

  8. Quantitative imaging of the microbubble concentrations by using an in-line phase contrast tomosynthesis prototype: a preliminary phantom study

    NASA Astrophysics Data System (ADS)

    Wu, Di; Ghani, Muhammad U.; Wong, Molly D.; Li, Yuhua; Yang, Kai; Chen, Wei R.; Zheng, Bin; Liu, Hong

    2016-03-01

    The purpose of this study is to demonstrate the feasibility of using a high-energy in-line phase contrast tomosynthesis system to quantitatively imaging microbubbles in a tissue simulating phantom under a limited radiation dose. The imaging system used in the investigation was a bench top in-line phase contrast tomosynthesis prototype operated under 120 kVp tube voltage and 0.5 mA tube current. A prime beam filter made of 2.3 mm Cu, 0.8 mm Pb and 1.0 mm Al was employed to obtain as large as possible portion of x-ray photon energy higher than 60 keV. The tissue simulating phantom was built by three acrylic slabs and a wax slab to mimic a 40 mm thick compressed breast. There were two tiny-sized structures with average 1 mm depth engraved on the two different layers. The microbubble suspensions with different concentrations were injected into those tiny structures. The inline phase contrast angular projections acquired were used to reconstruct the in-plane slices of the tiny structures on different layers. The CNRs vs microbubble concentrations were investigated. As the result, the microbubble suspensions were clearly visible, showing higher CNR when compared with the areas with no microbubble. Furthermore, a monotonously increasing relation between CNRs and microbubble concentrations was observed after calculating the area CNR of the phase contrast tomosynthesis slices.

  9. Numerical techniques for the solution of the compressible Navier-Stokes equations and implementation of turbulence models. [separated turbulent boundary layer flow problems

    NASA Technical Reports Server (NTRS)

    Baldwin, B. S.; Maccormack, R. W.; Deiwert, G. S.

    1975-01-01

    The time-splitting explicit numerical method of MacCormack is applied to separated turbulent boundary layer flow problems. Modifications of this basic method are developed to counter difficulties associated with complicated geometry and severe numerical resolution requirements of turbulence model equations. The accuracy of solutions is investigated by comparison with exact solutions for several simple cases. Procedures are developed for modifying the basic method to improve the accuracy. Numerical solutions of high-Reynolds-number separated flows over an airfoil and shock-separated flows over a flat plate are obtained. A simple mixing length model of turbulence is used for the transonic flow past an airfoil. A nonorthogonal mesh of arbitrary configuration facilitates the description of the flow field. For the simpler geometry associated with the flat plate, a rectangular mesh is used, and solutions are obtained based on a two-equation differential model of turbulence.

  10. Terahertz inline wall thickness monitoring system for plastic pipe extrusion

    NASA Astrophysics Data System (ADS)

    Hauck, J.; Stich, D.; Heidemeyer, P.; Bastian, M.; Hochrein, T.

    2014-05-01

    Conventional and commercially available inline wall thickness monitoring systems for pipe extrusion are usually based on ultrasonic or x-ray technology. Disadvantages of ultrasonic systems are the usual need of water as a coupling media and the high damping in thick walled or foamed pipes. For x-ray systems special safety requirements have to be taken into account because of the ionizing radiation. The terahertz (THz) technology offers a novel approach to solve these problems. THz waves have many properties which are suitable for the non-destructive testing of plastics. The absorption of electrical isolators is typically very low and the radiation is non-ionizing in comparison to x-rays. Through the electromagnetic origin of the THz waves they can be used for contact free measurements. Foams show a much lower absorption in contrast to acoustic waves. The developed system uses THz pulses which are generated by stimulating photoconductive switches with femtosecond laser pulses. The time of flight of THz pulses can be determined with a resolution in the magnitude of several ten femtoseconds. Hence the thickness of an object like plastic pipes can be determined with a high accuracy by measuring the time delay between two reflections on materials interfaces e.g. at the pipe's inner and outer surface, similar to the ultrasonic technique. Knowing the refractive index of the sample the absolute layer thickness from the transit time difference can be calculated easily. This method in principle also allows the measurement of multilayer systems and the characterization of foamed pipes.

  11. Terahertz inline wall thickness monitoring system for plastic pipe extrusion

    SciTech Connect

    Hauck, J. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Stich, D. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Heidemeyer, P. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Bastian, M. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Hochrein, T. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de

    2014-05-15

    Conventional and commercially available inline wall thickness monitoring systems for pipe extrusion are usually based on ultrasonic or x-ray technology. Disadvantages of ultrasonic systems are the usual need of water as a coupling media and the high damping in thick walled or foamed pipes. For x-ray systems special safety requirements have to be taken into account because of the ionizing radiation. The terahertz (THz) technology offers a novel approach to solve these problems. THz waves have many properties which are suitable for the non-destructive testing of plastics. The absorption of electrical isolators is typically very low and the radiation is non-ionizing in comparison to x-rays. Through the electromagnetic origin of the THz waves they can be used for contact free measurements. Foams show a much lower absorption in contrast to acoustic waves. The developed system uses THz pulses which are generated by stimulating photoconductive switches with femtosecond laser pulses. The time of flight of THz pulses can be determined with a resolution in the magnitude of several ten femtoseconds. Hence the thickness of an object like plastic pipes can be determined with a high accuracy by measuring the time delay between two reflections on materials interfaces e.g. at the pipe's inner and outer surface, similar to the ultrasonic technique. Knowing the refractive index of the sample the absolute layer thickness from the transit time difference can be calculated easily. This method in principle also allows the measurement of multilayer systems and the characterization of foamed pipes.

  12. Separated flow

    NASA Technical Reports Server (NTRS)

    Sellers, W. L., III; Dunham, R. E., Jr.; Goodman, W. L.; Howard, F. G.; Margason, R. J.; Rudy, D. H.; Rumsey, C. L.; Stough, H. P., III; Thomas, J. L.

    1986-01-01

    A brief overview of flow separation phenomena is provided. Langley has many active research programs in flow separation related areas. Three cases are presented which describe specific examples of flow separation research. In each example, a description of the fundamental fluid physics and the complexity of the flow field is presented along with a method of either reducing or controlling the extent of separation. The following examples are discussed: flow over a smooth surface with an adverse pressure gradient; flow over a surface with a geometric discontinuity; and flow with shock-boundary layer interactions. These results will show that improvements are being made in the understanding of flow separation and its control.

  13. Embedded computer controlled premixing inline injection system for air-assisted variable-rate sprayers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improvements to reduce chemical waste and environmental pollution for variable-rate sprayers used in orchards and ornamental nurseries require inline injection techniques. A microprocessor controlled premixing inline injection system implementing a ceramic piston chemical metering pump and two small...

  14. Inline Electrical Connector Mate/Demate Pliers

    NASA Technical Reports Server (NTRS)

    Yutko, Brian; Dininny, Michael; Moscoso, Gerand; Dokos, Adam

    2010-01-01

    Military and aerospace industries use Mil-Spec type electrical connections on bulkhead panels that require inline access for mate and demate operations. These connectors are usually in tight proximity to other connectors, or recessed within panels. The pliers described here have been designed to work in such tight spaces, and consist of a mirrored set of parallel handles, two cross links, two return springs, and replaceable polyurethane-coated end effectors. The polyurethane eliminates metal-to-metal contact and provides a high-friction surface between the jaw and the connector. Operationally, the user would slide the pliers over the connector shell until the molded polyurethane lip makes contact with the connector shell edge. Then, by squeezing the handles, the end effector jaws grip the connector shell, allowing the connector to be easily disconnected by rotating the pliers. Mating the connector occurs by reversing the prescribed procedure, except the connector shell is placed into the jaws by hand. The molded lip within the jaw allows the user to apply additional force for difficult-to-mate connectors. Handle design has been carefully examined to maximize comfort, limit weight, incorporate tether locations, and improve ergonomics. They have been designed with an off-axis offset for wiring harness clearance, while placing the connector axis of rotation close to the user s axis of wrist rotation. This was done to eliminate fatigue during multiple connector panel servicing. To limit handle opening width, with user ergonomics in mind, the pliers were designed using a parallel jaw mechanism. A cross-link mechanism was used to complete this task, while ensuring smooth operation.

  15. In-line phase shift tomosynthesis

    SciTech Connect

    Hammonds, Jeffrey C.; Price, Ronald R.; Pickens, David R.; Donnelly, Edwin F.

    2013-08-15

    Purpose: The purpose of this work is to (1) demonstrate laboratory measurements of phase shift images derived from in-line phase-contrast radiographs using the attenuation-partition based algorithm (APBA) of Yan et al.[Opt. Express 18(15), 16074–16089 (2010)], (2) verify that the APBA reconstructed images obey the linearity principle, and (3) reconstruct tomosynthesis phase shift images from a collection of angularly sampled planar phase shift images.Methods: An unmodified, commercially available cabinet x-ray system (Faxitron LX-60) was used in this experiment. This system contains a tungsten anode x-ray tube with a nominal focal spot size of 10 μm. The digital detector uses CsI/CMOS with a pixel size of 50 × 50 μm. The phantoms used consisted of one acrylic plate, two polystyrene plates, and a habanero pepper. Tomosynthesis images were reconstructed from 51 images acquired over a ±25° arc. All phase shift images were reconstructed using the APBA.Results: Image contrast derived from the planar phase shift image of an acrylic plate of uniform thickness exceeded the contrast of the traditional attenuation image by an approximate factor of two. Comparison of the planar phase shift images from a single, uniform thickness polystyrene plate with two polystyrene plates demonstrated an approximate linearity of the estimated phase shift with plate thickness (−1600 rad vs −2970 rad). Tomographic phase shift images of the habanero pepper exhibited acceptable spatial resolution and contrast comparable to the corresponding attenuation image.Conclusions: This work demonstrated the feasibility of laboratory-based phase shift tomosynthesis and suggests that phase shift imaging could potentially provide a new imaging biomarker. Further investigation will be needed to determine if phase shift contrast will be able to provide new tissue contrast information or improved clinical performance.

  16. In-line hologram segmentation for volumetric samples.

    PubMed

    Orzó, László; Göröcs, Zoltán; Fehér, András; Tőkés, Szabolcs

    2013-01-01

    We propose a fast, noniterative method to segment an in-line hologram of a volumetric sample into in-line subholograms according to its constituent objects. In contrast to the phase retrieval or twin image elimination algorithms, we do not aim or require to reconstruct the complex wave field of all the objects, which would be a more complex task, but only provide a good estimate about the contribution of the particular objects to the original hologram quickly. The introduced hologram segmentation algorithm exploits the special inner structure of the in-line holograms and applies only the estimated supports and reconstruction distances of the corresponding objects as parameters. The performance of the proposed method is demonstrated and analyzed experimentally both on synthetic and measured holograms. We discussed how the proposed algorithm can be efficiently applied for object reconstruction and phase retrieval tasks. PMID:23292422

  17. In-line digital holographic imaging in volume holographic microscopy.

    PubMed

    Zhai, Xiaomin; Lin, Wei-Tang; Chen, Hsi-Hsun; Wang, Po-Hao; Yeh, Li-Hao; Tsai, Jui-Chang; Singh, Vijay Raj; Luo, Yuan

    2015-12-01

    A dual-plane in-line digital holographic imaging method incorporating volume holographic microscopy (VHM) is presented to reconstruct objects in a single shot while eliminating zero-order and twin-image diffracted waves. The proposed imaging method is configured such that information from different axial planes is acquired simultaneously using multiplexed volume holographic imaging gratings, as used in VHM, and recorded as in-line holograms where the corresponding reference beams are generated in the fashion of Gabor's in-line holography. Unlike conventional VHM, which can take axial intensity information only at focal depths, the proposed method digitally reconstructs objects at any axial position. Further, we demonstrate the proposed imaging technique's ability to effectively eliminate zero-order and twin images for single-shot three-dimensional object reconstruction. PMID:26625046

  18. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  19. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  20. 40 CFR 63.1343 - Standards for kilns and in-line kiln/raw mills.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Standards for kilns and in-line kiln... Industry Emission Standards and Operating Limits § 63.1343 Standards for kilns and in-line kiln/raw mills. (a) General. The provisions in this section apply to each kiln, each in-line kiln/raw mill, and...

  1. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  2. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  3. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  4. Fluorescence detection by intensity changes for high-performance thin-layer chromatography separation of lipids using automated multiple development.

    PubMed

    Cebolla, Vicente L; Jarne, Carmen; Domingo, Pilar; Domínguez, Andrés; Delgado-Camón, Aránzazu; Garriga, Rosa; Galbán, Javier; Membrado, Luis; Gálvez, Eva M; Cossío, Fernando P

    2011-05-13

    Changes in emission of berberine cation, induced by non-covalent interactions with lipids on silica gel plates, can be used for detecting and quantifying lipids using fluorescence scanning densitometry in HPTLC analysis. This procedure, referred to as fluorescence detection by intensity changes (FDIC) has been used here in combination with automated multiple development (HPTLC/AMD), a gradient-based separation HPTLC technique, for separating, detecting and quantifying lipids from different families. Three different HPTLC/AMD gradient schemes have been developed for separating: neutral lipid families and steryl glycosides; different sphingolipids; and sphingosine-sphinganine mixtures. Fluorescent molar responses of studied lipids, and differences in response among different lipid families have been rationalized in the light of a previously proposed model of FDIC response, which is based on ion-induced dipole interactions between the fluorophore and the analyte. Likewise, computational calculations using molecular mechanics have also been a complementary useful tool to explain high FDIC responses of cholesteryl and steryl-derivatives, and moderate responses of sphingolipids. An explanation for the high FDIC response of cholesterol, whose limit of detection (LOD) is 5 ng, has been proposed. Advantages and limitations of FDIC application have also been discussed. PMID:21145556

  5. MOCVD for solar cells, a transition towards a chamberless inline process

    NASA Astrophysics Data System (ADS)

    Barrioz, V.; Monir, S.; Kartopu, G.; Lamb, D. A.; Brooks, W.; Siderfin, P.; Jones, S.; Clayton, A. J.; Irvine, S. J. C.

    2015-03-01

    MOCVD has been associated with batch processing of III-V opto-electronic devices for decades, with epitaxial structures deposited on up to 200 mm diameter wafers. Recent development in thin film PV has seen the gap in conversion efficiencies closing in on that of the commonly found multicrystalline Si wafer based PV. To further improve the conversion efficiency of thin film PV towards the theoretical limits of single junction solar cells requires a technique such as MOCVD with scalability potential. Preliminary results on the development of a chamberless inline process are reported for up to 15 cm wide float glass, progressively coating each layer in the CdTe solar cell as the heated substrate passes under each coating head in turn and entirely at atmospheric pressure. Emphasis is made on ensuring that the chamberless coating heads can be operated safely using a combination of nitrogen curtain flows and a balanced exhaust pressure system. Results are also presented on the exclusion of oxygen and moisture from the coating area, achieved using the same gas flow isolation process. This paper also reviews the achievements made to-date in the transfer of the high efficiency batch MOCVD produced CdTe solar cell to the chamberless inline process demonstrating device quality thin films deposition.

  6. An experimental and computational investigation of the flow field about a transonic airfoil in supercritical flow with turbulent boundary-layer separation

    NASA Technical Reports Server (NTRS)

    Rubesin, M. W.; Okuno, A. F.; Levy, L. L., Jr.; Mcdevitt, J. B.; Seegmiller, H. L.

    1976-01-01

    A combined experimental and computational research program is described for testing and guiding turbulence modeling within regions of separation induced by shock waves incident in turbulent boundary layers. Specifically, studies are made of the separated flow the rear portion of an 18%-thick circular-arc airfoil at zero angle of attack in high Reynolds number supercritical flow. The measurements include distributions of surface static pressure and local skin friction. The instruments employed include highfrequency response pressure cells and a large array of surface hot-wire skin-friction gages. Computations at the experimental flow conditions are made using time-dependent solutions of ensemble-averaged Navier-Stokes equations, plus additional equations for the turbulence modeling.

  7. Desorption electrospray ionization mass spectrometry analysis of lipids after two-dimensional high-performance thin-layer chromatography partial separation

    PubMed Central

    Paglia, Giuseppe; Ifa, Demian R.; Wu, Chunping; Corso, Gaetano; Cooks, R. Graham

    2010-01-01

    Molecular imaging of separate but still incompletely resolved spots on high-performance thin-layer chromatography (HPTLC) plates is used for the direct analysis of porcine brain lipids by desorption electrospray ionization mass spectrometry (DESI-MS). Seven class-specific spots were imaged in the negative ion mode and shown to contain more than fifty lipids. A low lateral resolution of 400 × 400 μm allowed simple, rapid and incomplete separation to be combined with DESI imaging for the identification of many components of these extremely complex mixtures. In this work, tandem mass spectrometry (MS/MS) was also employed to confirm the identity of particular lipids directly on HPTLC plates. PMID:20128616

  8. Problem of soot aggregates separation and purification for Carbon isotopic composition analyses - burning experiment and real black layers from speleothems examples

    NASA Astrophysics Data System (ADS)

    Hercman, Helena; Zawidzki, Pawel; Majewska, Agata

    2015-04-01

    Burning products are often used as an indicator of fire or prehistoric men activities. When it consists of macroscopically visible black layer it may be studied by different methods. When it is dispersed within sediment it is necessary to apply method for burning product separation. Soot aggregates as a result of incomplete combustion of organic materials are most reliable indication of burning. Size of soot particles is too small to observe by optical microscopy. There are two main advantages of application of transmission electron microscopy (TEM) for investigations of samples formed as a result of organic materials (like wood) combustion. First, it makes possible to investigate not only morphology but also its interior structure. The carbon layers arrangement is characteristic for particles obtained from combustion processes, and it directly confirm that these particles were formed that way. And second, analysis of chemical composition using of EDS spectroscopy in transmission microscope are precise and it spatial resolution is about a few nanometers. Burning chamber for wood burning experiments was constructed. It allows wood burning with controlling of burning temperature, carbon isotopic composition in carbon dioxide of burning atmosphere and carbon dioxide originated during burning. Burning products are collected on the plates with controlling of plates material, temperature and distance from flame. Two types of samples were studied. The first type of samples consisted the products of recent wood burning. The second type of samples consisted of black layers collected from speleothems. Soot aggregates were chemically separated from other burning products collected on plates. Process of chemical separation and purity of soot material were tested by TEM observations. Isotopic carbon composition at each step of soot separation as well as original wood fragments was analysed at the Isotopic Laboratory for Dating and Palaeoenvironment Studies, Polish Academy of

  9. Experimental study of separated ramp-induced shock/boundary-layer interaction with upstream micro-vortex generator at Mach

    NASA Astrophysics Data System (ADS)

    Shih, Yusi

    Shock wave/boundary layer interactions (SBLIs) are important issues for high-speed vehicles. SBLIs reduce the performance of aerodynamic surfaces and engine inlets, amongst a number of adverse effects. Micro-vortex generators (MVGs) are a flow control method with strong potential to mitigate the effects of SBLI by energizing the boundary layer through momentum transfers from the freestream. They have been implemented in actual configurations at low speeds. The present research includes a combined experimental and theoretical analysis of the evolution of the perturbation downstream the MVG, the formation of vortices, and their interaction with the shock front. Experiments were performed with a baseline MVG configuration of 90° trailing edge on flat plate, ramp alone, and also with MVG mounted ahead of a 20° ramp. The surface flow visualization and particle image velocimetry (PIV) results are presented; the surface flow visualization shows a substantial suppression of SBLIs. A new method to quantify the effectiveness of the MVG on the shock recompression is presented. Moreover, the PIV results were used as the initial input values for the simulation work. A theoretical analysis of the interaction of the MVG perturbation with the boundary layer is performed by assuming linear dynamics of the perturbation. The major assumption is that the interaction between MVG perturbation and the shear flow is affected by transient growth as a result of the non-orthogonality of the linearized Navier-Stokes equations. A new method to perform the projection of the measured perturbation on the continuous modes of the boundary layer is presented. The method takes advantage of the biorthogonality of the direct and adjoint modes. The implementation of such a method using both the Chebyshev polynomials and a shooting algorithm is discussed. The results of the theoretical analysis are encouraging and display a similar trend as the experiments. Both experimental and theoretical results

  10. Updates to In-Line Calculation of Photolysis Rates

    EPA Science Inventory

    How photolysis rates are calculated affects ozone and aerosol concentrations predicted by the CMAQ model and the model?s run-time. The standard configuration of CMAQ uses the inline option that calculates photolysis rates by solving the radiative transfer equation for the needed ...

  11. Separation optimization of long porous-layer open-tubular columns for nano-LC-MS of limited proteomic samples.

    PubMed

    Rogeberg, Magnus; Vehus, Tore; Grutle, Lene; Greibrokk, Tyge; Wilson, Steven Ray; Lundanes, Elsa

    2013-09-01

    The single-run resolving power of current 10 μm id porous-layer open-tubular (PLOT) columns has been optimized. The columns studied had a poly(styrene-co-divinylbenzene) porous layer (~0.75 μm thickness). In contrast to many previous studies that have employed complex plumbing or compromising set-ups, SPE-PLOT-LC-MS was assembled without the use of additional hardware/noncommercial parts, additional valves or sample splitting. A comprehensive study of various flow rates, gradient times, and column length combinations was undertaken. Maximum resolution for <400 bar was achieved using a 40 nL/min flow rate, a 400 min gradient and an 8 m long column. We obtained a 2.3-fold increase in peak capacity compared to previous PLOT studies (950 versus previously obtained 400, when using peak width = 2σ definition). Our system also meets or surpasses peak capacities obtained in recent reports using nano-ultra-performance LC conditions or long silica monolith nanocolumns. Nearly 500 proteins (1958 peptides) could be identified in just one single injection of an extract corresponding to 1000 BxPC3 beta catenin (-/-) cells, and ~1200 and 2500 proteins in extracts of 10,000 and 100,000 cells, respectively, allowing detection of central members and regulators of the Wnt signaling pathway. PMID:23813982

  12. Magnetic phase separation in double layer ruthenates Ca3(Ru1−xTix)2O7

    PubMed Central

    Peng, Jin; Liu, J. Y.; Hu, J.; Mao, Z. Q.; Zhang, F. M.; Wu, X. S.

    2016-01-01

    A phase transition from metallic AFM-b antiferromagnetic state to Mott insulating G-type antiferromagnetic (G-AFM) state was found in Ca3(Ru1−xTix)2O7 at about x = 0.03 in our previous work. In the present, we focused on the study of the magnetic transition near the critical composition through detailed magnetization measurements. There is no intermediate magnetic phases between the AFM-b and G-AFM states, which is in contrasted to manganites where a similar magnetic phase transition takes place through the presence of several intermediate magnetic phases. The AFM-b-to-G-AFM transition in Ca3(Ru1−xTix)2O7 happens through a phase separation process in the 2–5% Ti range, whereas similar magnetic transitions in manganites are tuned by 50–70% chemical substitutions. We discussed the possible origin of such an unusual magnetic transition and compared with that in manganites. PMID:26771083

  13. Photonic crystal fiber in-line Mach-Zehnder interferometer for explosive detection.

    PubMed

    Tao, Chuanyi; Wei, Heming; Feng, Wenlin

    2016-02-01

    We report a photonic crystal fiber (PCF) in-line Mach-Zehnder interferometer used as a gas sensor device which exhibits high sensitivity to the explosive trinitrotoluene (TNT). The interferometric sensor head is formed by embedding a segment of large-mode-area/grapefruit PCF between standard single-mode fibers via butt coupling, which produces two small air gaps in between terminated fiber ends with ceramic ferrule connectors as coupling regions, which also serve as inlet/outlet for the gas. The spectral response of the interferometer is investigated in terms of its wavelength spectrum. The selectivity to TNT vapor is achieved by immobilizing a molecular recognition ployallylamine layer on the inner surface of the holey region of the PCF. The TNT-induced variations of the interference fringes are measured and the sensing capability of the proposed sensor is demonstrated experimentally. PMID:26906849

  14. Combined urea-thin layer chromatography and silver nitrate-thin layer chromatography for micro separation and determination of hard-to-detect branched chain fatty acids in natural lipids.

    PubMed

    Yan, Yuanyuan; Wang, Xingguo; Liu, Yijun; Xiang, Jingying; Wang, Xiaosan; Zhang, Huijun; Yao, Yunping; Liu, Ruijie; Zou, Xiaoqiang; Huang, Jianhua; Jin, Qingzhe

    2015-12-18

    A simple, fast and efficient procedure was developed for micro separation and enrichment of branched chain fatty acids (BCFA) from natural products using successive thin layer chromatography (TLC) technique coupling novel urea-TLC with AgNO3-TLC, which rely on the formation of urea adduction and AgNO3 bonding in methanol. These natural lipids contain a significant amount of straight chain fatty acids (FA). Fresh and fast urea-TLC and AgNO3-TLC plate making techniques were developed with more even coating and less coating material contamination before being utilized for separation. Goat milk fat was used as a model. Various experimental parameters that affect urea-TLC and AgNO3-TLC separation of BCFA were investigated and optimized, including coating of urea, concentration of original oil sample, mobile phase and sample application format. High efficiency of removal of straight chain FA was achieved with a low amount of sample in an easy and fast way. A total BCFA mix with much higher purity than previous studies was successfully achieved. The developed method has also been applied for the concentration and analysis of BCFA in cow milk fat and Anchovy oil. PMID:26614174

  15. In-line beam current monitor

    NASA Astrophysics Data System (ADS)

    Ekdahl, C. A., Jr.; Frost, C. A.

    1984-11-01

    An intense relativistic electron beam current monitor for a gas neutralized beam transport line includes a first foil for conducting plasma current to the wall where it is measured as it traverses an inductive loop formed by a cavity in the wall. An insulator foil separates the first foil from a second conducting foil which returns the current to the plasma environment.

  16. In-line beam current monitor

    DOEpatents

    Ekdahl, Jr., Carl A.; Frost, Charles A.

    1986-01-01

    An intense relativistic electron beam current monitor for a gas neutralized beam transport line includes a first foil for conducting plasma current to the wall where it is measured as it traverses an inductive loop formed by a cavity in the wall. An insulator foil separates the first foil from a second conducting foil which returns the current to the plasma environment.

  17. In-line beam current monitor

    DOEpatents

    Ekdahl, C.A. Jr.; Frost, C.A.

    1984-11-13

    An intense relativistic electron beam current monitor for a gas neutralized beam transport line includes a first foil for conducting plasma current to the wall where it is measured as it traverses an inductive loop formed by a cavity in the wall. An insulator foil separates the first foil from a second conducting foil which returns the current to the plasma environment.

  18. Effects of ovarian steroids upon responses mediated by adrenoceptors in separated layers of the myometrium and in the costo-uterine muscle of the guinea-pig

    PubMed Central

    Hartley, Margaret L.; Pennefather, Jocelyn N.; Story, Margot E.

    1983-01-01

    1 This study describes the effects of ovarian steroid hormones upon the responses to adrenoceptor agonists of isolated myometrium, separated into its longitudinal and circular layers, and of costo-uterine muscle from guinea-pigs. The preparations were field-stimulated at 100 s intervals, and the adrenoceptor agonists phenylephrine and isoprenaline produced enhancement or inhibition of the evoked contractions. 2 Isoprenaline produced propranolol-sensitive inhibitory effects in longitudinal and circular myometrium and costo-uterine muscle preparations from animals from all experimental groups: i.e. from nonsteroid-treated animals (ovariectomized and intact); intact animals treated with either oestrogen or progesterone alone; ovariectomized animals treated with oestrogen; ovariectomized and intact animals treated with progesterone following oestrogen priming; and from animals 1-4 days post-partum. Longitudinal myometrial preparations from progesterone-treated oestrogen-primed and from post-partum animals were most sensitive to this agonist. 3 Phenylephrine produced phentolamine-sensitive excitatory effects in circular myometrial and costo-uterine muscle preparations from animals from all the experimental groups. In contrast, propranolol-sensitive inhibitory responses to phenylephrine occurred in longitudinal myometrial preparations taken from animals treated with progesterone following oestrogen priming, and from post-partum animals. Longitudinal myometrium from animals from the remaining experimental groups exhibited phentolamine-sensitive excitatory responses to phenylephrine. 4 The basis for the selective effect upon the longitudinal myometrium of exposure to progesterone following a period of oestrogen priming, is discussed. The results described are consistent with the possibility that in the longitudinal layer of guinea-pig uterus exposed to progesterone following oestrogen priming there is an increase in the proportion of β-adrenoceptors in this layer. This

  19. Separation of Scaptotrigona postica workers into defined task groups by the chemical profile on their epicuticle wax layer.

    PubMed

    Poiani, Silvana B; Morgan, E David; Drijfhout, Falko P; da Cruz-Landim, Carminda

    2014-04-01

    During evolution, the cuticle surface of insects acquired functions in communication, such as inter- and intra-specific recognition, identification of gender, physiological state, and fertility. In eusocial bees, the information in the cuticular surface is important not only to discriminate nestmates from non-nestmates but also to identify an individual's class, life phase or task. A comparative study of the cuticular surface chemical profile of workers of Scaptotrigona postica in different phases of life, i.e., newly emerged workers (NE), brood comb area workers (CA), and forager workers (FO) was undertaken by gas chromatography linked to mass spectrometry. Multivariate statistical analysis was performed to verify how workers are grouped according to their chemical profile and to determine which compounds are responsible for separating them into groups. The cuticle surface of workers contains mainly hydrocarbons and a small amount of oxygenated compounds. Multivariate statistical analysis showed qualitative and quantitative variation in relation to the life phases/tasks performed, and all groups were distinct. The most abundant compound found in NE and CA was n-heptacosane, while in FO, it was (Z)-9-heptacosene. The compounds that differentiate NE from other groups are n-tricosane and n-hexacosane. A (Z)-X-octacosene and n-nonacosane are the chemicals that distinguish CA from NE and FO, while 11- and 13-methylpentacosane, (Z)-X-hexacosene, and (Z)-9-heptacosene characterize FO as distinct from NE and CA. The probable function of alkenes is nestmate recognition, mainly in FO. The results show that the cuticle surfaces of workers are characteristic of the phase of life/task performed by workers, allowing intra-colonial recognition. PMID:24752855

  20. Microscale extraction and phase separation using a porous capillary.

    PubMed

    Phillips, Thomas W; Bannock, James H; deMello, John C

    2015-07-21

    We report the use of a porous polytetrafluoroethylene capillary for the inline separation of liquid-liquid segmented flows, based on the selective wetting and permeation of the porous capillary walls by one of the liquids. Insertion of a narrow flow restriction at the capillary outlet allows the back pressure to be tuned for multiple liquid-liquid combinations and flow conditions. In this way, efficient separation of aqueous-organic, aqueous-fluorous and organic-fluorous segmented flows can be readily achieved over a wide range of flow rates. The porous-capillary-separator enables the straightforward regeneration of a continuous flow from a segmented flow, and may be applied to various applications, including inline analysis, biphasic reactions, and purification. As a demonstration of the latter, we performed a simple inline aqueous-organic extraction of the pH indicator 2,6-dichloroindophenol. An aqueous solution of the conjugate base was mixed with hydrochloric acid in continuous flow to protonate the indicator and render it organic-soluble. The indicator was then extracted from the aqueous feed into chloroform using a segmented flow. The two liquids were finally separated inline using a porous PTFE capillary, with the aqueous phase emerging as a continuous stream from the separator outlet. UV-visible absorption spectroscopy showed the concentration of indicator in the outflowing aqueous phase to be less than one percent of its original value, confirming the efficacy of the extraction and separation process. PMID:26054926

  1. Advanced in-line metrology strategy for self-aligned quadruple patterning

    NASA Astrophysics Data System (ADS)

    Chao, Robin; Breton, Mary; L'herron, Benoit; Mendoza, Brock; Muthinti, Raja; Nelson, Florence; De La Pena, Abraham; Le, Fee li; Miller, Eric; Sieg, Stuart; Demarest, James; Gin, Peter; Wormington, Matthew; Cepler, Aron; Bozdog, Cornel; Sendelbach, Matthew; Wolfling, Shay; Cardinal, Tom; Kanakasabapathy, Sivananda; Gaudiello, John; Felix, Nelson

    2016-03-01

    geometry and must be used carefully. A successful implementation of SAQP process control for yield improvement requires the metrology issues to be addressed. By optimizing the measurement parameters and beam configurations, CDSEM measurements distinguish each of the spaces corresponding to the upstream mandrel processes and report their CDs separately to feed back to the process team for the next development cycle. We also utilize the unique capability in scatterometry to measure the structure details in-line and implement a "predictive" process control, which shows a good correlation between the "predictive" measurement and the cross-sections from our design of experiments (DOE). The ability to measure the pitch walk in scatterometry was also demonstrated. This work also explored the frontier of in-line XRD capability by enabling an automatic RSM fitting on tool to output pitch walk values. With these advances in metrology development, we are able to demonstrate the impacts of in-line monitoring in the SAQP process, to shorten the patterning development learning cycle to improve the yield.

  2. In-line process instrumentation for geothermal power plants

    SciTech Connect

    Shannon, D.W.; Robertus, R.J.; Sullivan, R.G.; Kindle, C.H.; Pierce, D.D.

    1985-05-01

    The economics of geothermal power depend on satisfactory plant reliability of continuous operation. Plant problems and extended downtime due to corrosion failures, scale buildup, or injection well plugging have affected many past geothermal projects. If in-line instrumentation can be developed to alert plant operators to correctable problems, then the cost and reliability of geothermal power will be improved. PNL has completed a problem of development of in-line corrosion and chemical instrumentation for binary cycle plants, and this technology has been used to set up a monitoring program at the Heber Binary Demonstration Power Plant. The current emphasis has shifted to development of particle meters for use on injection lines and CO/sub 2/ and pH probes for use in control of calcite scaling. Plans have been outlined to develop and demonstrate flash plant instrumentation for corrosion monitoring, scaling, steam purity, and injection line particle counting. 2 refs., 17 figs., 1 tab.

  3. Retractable pin dual in-line package test clip

    SciTech Connect

    Bandzuch, G.S.; Kosslow, W.J

    1993-12-31

    This invention is a Dual In-line Package (DIP) test clip for use when troubleshooting circuits containing DIP integrated circuits. This test clip is a significant improvement over existing DIP test clips in that it has retractable pins which will permit troubleshooting without risk of accidentally shorting adjacent pins together when moving probes to different pins on energized circuits or when the probe is accidentally bumped while taking measurements.

  4. Retractable pin dual in-line package test clip

    DOEpatents

    Bandzuch, Gregory S.; Kosslow, William J.

    1996-01-01

    This invention is a Dual In-Line Package (DIP) test clip for use when troubleshooting circuits containing DIP integrated circuits. This test clip is a significant improvement over existing DIP test clips in that it has retractable pins which will permit troubleshooting without risk of accidentally shorting adjacent pins together when moving probes to different pins on energized circuits or when the probe is accidentally bumped while taking measurements.

  5. Evaluation of an in-line dilutor for submicron aerosols

    SciTech Connect

    Yeh, H.C.; Cheng, Y.S.; Carpenter, R.L.

    1983-05-01

    The performance of an in-line aerosol dilutor, consisting of a stainless steel capillary tube within a standard 47-mm Gelman filter assembly, was evaluated. The dilution ratio was found to be weakly dependent on particle size and flow rate. A theory was developed to predict the dilution ratio based on the pressure drop across the dilutor. The agreement between the theory and the data was good and within +/- 10%.

  6. Lensless in-line holographic microscope with Talbot grating illumination.

    PubMed

    Feng, Shaodong; Wang, Mingjun; Wu, Jigang

    2016-07-15

    We have developed a wide field-of-view lensless in-line holographic microscope (LIHM) capable of acquiring microscopic images with a compact design. In our imaging system, a Ronchi grating was illuminated by a collimated laser beam to generate a Talbot self-imaging grating illumination on the sample, and the in-line holograms were recorded by a CMOS imaging sensor behind the sample. An iterative reconstruction algorithm was then applied to reconstruct the sample image while eliminating the twin-image background that appears in traditional in-line holography. In the algorithm, the dark areas of the illumination grating were used as a known constraint to define the sample support that led to convergence of the iteration. The whole-sample image can be acquired by laterally shifting the grating. We demonstrated the performance of our iteration algorithm and imaging system by successfully acquiring images of polystyrene microspheres with 5 μm diameter and the wing of a green lacewing. PMID:27420484

  7. A comprehensive test method for inline flame arresters

    SciTech Connect

    Roussakis, N.; Lapp, K. )

    1991-04-01

    The certification test standards that presently exist for flame arresters are highly inadequate for inline applications. A proper flame arrester test method should ensure that a unit will work with any flame front conditions that it could be exposed to in actual use. When evaluating flame arrester performance, it is just as dangerous to neglect deflagration testing as detonation testing. The comprehensive inline flame arrester test method outlined here involves exposing a unit to the entire flame propagation pressure spectrum. This includes low, medium and high pressure deflagrations as well as overdriven and stable detonations. The test method also takes into account the following factors: flow restriction on the protected side of the flame arrester, flame propagation through a flowing gas, initial system pressure and temperature, and specified gas mixture. Flow restriction on the protected side of the flame arrester has a very significant effect on performance and has not previously been given consideration in flame arrester testing. Besides moving flame front tests, endurance burn testing and hydrostatic pressure testing are also discussed here. Major regulatory organizations have recently adopted these findings as the basis for new standards proposed to cover an inline flame arrester test method.

  8. Reducing the Drag and Damage of a High-Speed Train by Analyzing and Optimizing its Boundary Layer Separation and Roll-up into Wake Vortices

    NASA Astrophysics Data System (ADS)

    Jiang, Chung-Hsiang; Marcus, Philip

    2012-11-01

    We present numerical calculations of the boundary layers and shed wake vortices behind several aerodynamic bodies and generic models of high-speed trains. Our calculations illustrate new visual diagnostics that we developed that clearly show where the separation of a boundary layer occurs and where, how, and with what angles (with respect to the stream-wise direction) the wake vortices form. The calculations also illustrate novel 3D morphing and mesh ``pushing and pulling'' techniques that allow us to change the shapes of aerodynamic bodies and models in a controlled and automated manner without spurious features appearing. Using these tools we have examined the patterns of the shed vortices behind generic bodies and trains and correlated them with the changes in the drag as well as with the effects of the shed vortices on the environment. In particular, we have applied these techniques to the end car of a next-generation, high-speed train in order to minimize the drag and to minimize the adverse effects of the shed vortices on the track ballast.

  9. Improvement in the Iatroscan thin-layer chromatographic-flame ionisation detection analysis of marine lipids. Separation and quantitation of monoacylglycerols and diacylglycerols in standards and natural samples.

    PubMed

    Striby, L; Lafont, R; Goutx, M

    1999-07-23

    Mono- and diacylglycerols are important intermediates in glycerolipid biodegradation and intracellular signalling pathways. A method for mass determination of these lipid classes in marine particles was developed using the Iatroscan, which combines thin layer chromatography (TLC) and flame ionisation detection (FID) techniques. We improved existing protocols by adding two elution steps: hexane-diethyl-ether-formic acid (70:30:0.2, v/v/v) after triacylglycerol and free fatty acid scan, and acetone 100% followed by chloroform-acetone-formic acid (99:1:0.2, v/v/v) after 1,2 diacylglycerols. Diacylglycerol isomers 1,2 and 1,3 were separated from each other, as well as from free sterols in standards and marine lipids from sediment trap particles. Monoacylglycerols were separated from pigments and galactosyl-lipids in the same trap samples and in a rich pigment phytoplankton extract of Dunaliella viridis. Quantitation of each class in samples was performed after calibration with 0.5 to 2 micrograms of standards. As many as 17 lipid classes can be identified and quantified in samples using this proposed six-step development. PMID:10457435

  10. Characterization of a high-energy in-line phase contrast tomosynthesis prototype

    PubMed Central

    Wu, Di; Yan, Aimin; Li, Yuhua; Wong, Molly D.; Zheng, Bin; Wu, Xizeng; Liu, Hong

    2015-01-01

    Purpose: In this research, a high-energy in-line phase contrast tomosynthesis prototype was developed and characterized through quantitative investigations and phantom studies. Methods: The prototype system consists of an x-ray source, a motorized rotation stage, and a CMOS detector with a pixel pitch of 0.05 mm. The x-ray source was operated at 120 kVp for this study, and the objects were mounted on the rotation stage 76.2 cm (R1) from the source and 114.3 cm (R2) from the detector. The large air gap between the object and detector guarantees sufficient phase-shift effects. The quantitative evaluation of this prototype included modulation transfer function and noise power spectrum measurements conducted under both projection mode and tomosynthesis mode. Phantom studies were performed including three custom designed phantoms with complex structures: a five-layer bubble wrap phantom, a fishbone phantom, and a chicken breast phantom with embedded fibrils and mass structures extracted from an ACR phantom. In-plane images of the phantoms were acquired to investigate their image qualities through observation, intensity profile plots, edge enhancement evaluations, and/or contrast-to-noise ratio calculations. In addition, the robust phase-attenuation duality (PAD)-based phase retrieval method was applied to tomosynthesis for the first time in this research. It was utilized as a preprocessing method to fully exhibit phase contrast on the angular projection before reconstruction. Results: The resolution and noise characteristics of this high-energy in-line phase contrast tomosynthesis prototype were successfully investigated and demonstrated. The phantom studies demonstrated that this imaging prototype can successfully remove the structure overlapping in phantom projections, obtain delineate interfaces, and achieve better contrast-to-noise ratio after applying phase retrieval to the angular projections. Conclusions: This research successfully demonstrated a high-energy in-line

  11. On current induced in-line oscillation of pipelines in free spans

    SciTech Connect

    Toerum, A.; Moe, G.; Johansen, J.V.; Katla, E.

    1996-12-01

    A review is given on some results from different investigations on current induced in-line vibrations (viv) of circular cylinders. Results of recent laboratory experiments are presented. An attempt has been made to explain why the laboratory experiments and field tests give different results. It is recommended that the results of the field measurements of HSE (1993) on in-line oscillations is used in engineering work to predict in-lines oscillation amplitudes until more results are available and further insight into the mechanisms of in-line oscillations is obtained.

  12. Nanometer-scale separation of d(10) Zn(2+)-layers and twin-shift competition in Ba8ZnNb6O24-based 8-layered hexagonal perovskites.

    PubMed

    Lu, Fengqi; Wang, Xiaoming; Pan, Zhengwei; Pan, Fengjuan; Chai, Shiqiang; Liang, Chaolun; Wang, Quanchao; Wang, Jing; Fang, Liang; Kuang, Xiaojun; Jing, Xiping

    2015-08-01

    The 8-layered shifted hexagonal perovskite compound Ba8ZnNb6O24 was isolated via controlling the ZnO volatilization, which features long-range B-cation ordering with nanometer-scale separation by ∼1.9 nm of octahedral d(10) cationic (Zn(2+)) layers within the purely corner-sharing octahedral d(0) cationic (Nb(5+)) host. The long-range ordering of the B-site vacancy and out-of-center distortion of the highly-charged d(0) Nb(5+) that is assisted by the second-order Jahn-Teller effect contribute to this unusual B-cation ordering in Ba8ZnNb6O24. A small amount (∼15%) of d(10) Sb(5+) substitution for Nb(5+) in Ba8ZnNb6-xSbxO24 dramatically transformed the shifted structure to a twinned structure, in contrast with the Ba8ZnNb6-xTaxO24 case requiring 50% d(0) Ta(5+) substitution for Nb(5+) for such a shift-to-twin transformation. Multiple factors including B-cationic sizes, electrostatic repulsion forces, long-range ordering of B-site vacancies, and bonding preferences arising from a covalent contribution to the B-O bonding that includes out-of-center octahedral distortion and the B-O-B bonding angle could subtly contribute to the twin-shift phase competition of B-site deficient 8-layered hexagonal perovskites Ba8B7O24. The ceramics of new shifted Ba8ZnNb6O24 and twinned Ba8ZnNb5.1Sb0.9O24 compounds exhibited good microwave dielectric properties (εr ∼ 35, Qf ∼ 36 200-43 400 GHz and τf ∼ 38-44 ppm/°C). PMID:26110444

  13. Size-based characterization of nanoparticle mixtures by the inline coupling of capillary electrophoresis to Taylor dispersion analysis.

    PubMed

    Oukacine, Farid; Morel, Aurélie; Desvignes, Isabelle; Cottet, Hervé

    2015-12-24

    Separation of closely related nanoparticles is still a challenging issue for the characterization of complex mixtures for industrial/research applications or regulatory purposes. In this work, the remarkable separating performances of CE were complemented with the absolute size-based determination provided by Taylor dispersion analysis (TDA) for the characterization of nanoparticle mixtures. The inline hyphenation of CE to TDA was successfully implemented for the baseline separation followed by a size-based characterization of a bimodal mixture containing two closely size-related nanolatexes (70nm and 56nm radii). A pixel sensor UV area imager providing three detection points along the capillary was used for a differential measurement of the peak broadening during the Taylor dispersion step. Comparison of this new technique with dynamic light scattering and hydrodynamic chromatography is also discussed. PMID:26653841

  14. a Numerical Study of Unsteady Fluid Flow in In-Line and Staggered Tube Banks

    NASA Astrophysics Data System (ADS)

    Beale, S. B.; Spalding, D. B.

    1999-08-01

    This paper is concerned with the results of numerical calculations for transient flow in in-line-square and rotated-square tube banks with a pitch-to-diameter ratio of 2:1, in the Reynolds number range of 30-3000. Transient-periodic behaviour is induced by the consideration of two or more modules, with a sinusoidal span-wise perturbation being applied in the upstream module. There is a triode-like effect, whereby the downstream response to the stimulus is amplified, and there is a net gain in the crosswise flow component. When an appropriate feedback mechanism is provided, a stable transient behaviour is obtained, with alternate vortices being shed from each cylinder. Flow visualization studies of the results of the calculations are presented together with quantitative details of pressure drop, lift, drag and heat transfer. For the staggered bank, a wake-switching or Coanda effect was observed as the serpentine-shaped wake attached to alternate sides of the downstream cylinder. The induced response is independent of the amplitude and frequency of the applied disturbance, including the case of spontaneous behaviour with no excitation mechanism. For the in-line case where each cylinder is in the shadow of the previous one, the motion is less pronounced; however, a shear-layer instability associated with the alternating spin of shed vortices was observed. In this case, the response was found to be somewhat dependent on the frequency of the applied disturbance, and a transient motion could not be induced spontaneously in the absence of an explicit feedback mechanism. Calculated Strouhal numbers were in fair agreement with experimental data: for the staggered geometry, they had values of between 0.26 and 0.35, or from -21 to +6% higher than measured values, while for the in-line geometry, the Strouhal numbers ranged between 0.09 and 0.12, or about 20-40% lower than experimental values.

  15. Optimization of in-line fritless solid-phase extraction for capillary electrophoresis-mass spectrometry.

    PubMed

    Tak, Yvonne H; Toraño, Javier Sastre; Somsen, Govert W; de Jong, Gerhardus J

    2012-12-01

    In this study, in-line frit-free solid-phase extraction (SPE) has been studied for the preconcentration of analytes prior to analysis by capillary electrophoresis-mass spectrometry (CE-MS). The mixed-mode sorbent Oasis HLB was selected for the trapping of compounds of different polarity. Using 2-ethylidene-1,5-dimethyl-3,3-diphenylpirrolidine (EDDP), dihydrocodeine and codeine as test compounds, SPE parameters such as the pH of the sample and composition of the washing and elution solvent were optimized. Trapping of the analytes was optimal at pH 8.0 or higher. For efficient elution of the SPE micro column, 85% of methanol in water with 2% (v/v) acetic acid was used, which also prevented current break down in subsequent CE analysis. CE resolution of the test compounds was highest for background electrolytes (BGEs) with a pH above 8. For optimal analysis, samples were 1:1 diluted with carbonate buffer (1M, pH 8.0) prior to analysis, BGE was 60mM ammonium acetate buffer (pH 10.0), and the injected sample volume was 60 μl (i.e., 30 capillary volumes). Good recoveries were found: 101% for EDDP, 88% for codeine and 90% for dihydrocodeine. Intraday RSDs for migration time and peak areas were below 0.56% and 15%, respectively. Peak widths at half height obtained with SPE-CE-MS were 12s for EDDP, 3.7s for dihydrocodeine and 7.4s for codeine, and were comparable to those for CE-MS. LODs were 0.22 pg/ml for EDDP, 2.1 pg/ml for dihydrocodeine and 24 pg/ml for codeine. It is concluded that the applied fritless in-line preconcentration construct proved to be highly useful for improving the sensitivity of CE while maintaining separation. PMID:22959866

  16. Inline sidewall angle monitoring of memory capacitor profiles

    NASA Astrophysics Data System (ADS)

    Rathsack, Ben M.; Bushman, Scott G.; Celii, Francis G.; Ayres, Stephen F.; Kris, Roman

    2005-05-01

    The integration of embedded ferroelectric random access memory (FRAM) into a standard CMOS flow requires significant control and characterization of the patterned capacitor sidewall angle. The electrical functionality of the FRAM capacitor is highly dependent on the post-etch sidewall characteristics of the TiAlN hardmask and Ir/PZT/Ir capacitor film stack. In this study, we explored various options for determining the sidewall profile of these capacitors including scanning electron microscope (SEM), atomic force microscopy (AFM) and scatterometry. A series of capacitor samples with ranges of sidewall slopes from 60 degrees to 80 degrees was generated to test each measuring technique's robustness. All of the techniques demonstrated relatively accurate sidewall angle measurements of the high-angle capacitor profiles relative to cross-section SEMs. However, the CD SEM had difficulty identifying the top edge of the low-angle capacitor samples due to the large amount of profile roughness, which induced a large measurement error range. Additional optimization is required to improve the CD SEM's precision, before it would be a viable in-line monitor for the FRAM process. The AFM provided good accuracy and precision on the high-angle capacitor profiles, but the tip size limited the measurements to spaces larger than 120 nm. Furthermore, the AFM had a long move-acquire-measure (MAM) time of 5 minutes/site, which limited its throughput as an inline monitor. The scatterometer predicted bottom-stack sidewall angle measurements (2 trapezoid model) that were consistent with the cross-section SEMs, and it produced the lowest across wafer sidewall angle range. It also had the fastest MAM time of 5 seconds/site compared to the other techniques. However, it was difficult to generate an accurate scatterometry model due to the complex optical film stack that incorporated low surface reflectivity and higher surface roughness. While each technique had limitations, scatterometry

  17. In-line digital holography with double knife edge

    NASA Astrophysics Data System (ADS)

    Ramirez, Claudio; Iemmi, Claudio; Campos, Juan

    2015-06-01

    We study and test a new technique for in-line digital holography which avoids the formation of the conjugate images. Inline digital holography is based in a common path configuration. In this case, the hologram is produced by the interference between the reference wave front and the diffracted wave front by an almost transparent object. Twin images are obtained with obscured rings that difficult the determination of the best focusing plane. To avoid the conjugated image, the information of the magnitude and phase of the wave front are needed. In a recent work a new in-line digital holography technique was proposed. In this method the object is illuminated with a collimated wave front. A plane, close to the particles distribution is imaged onto a CCD by means of a convergent lens and at the same time, a knife edge is placed in the focal plane of the lens in order to block half of spatial frequency spectrum. In this way, by means of a numerical processing performed on the Fourier plane, it is possible to eliminate one of the components (real or conjugate) of the reconstructed images nevertheless it is observed a tiny deformation of the resulting hologram image. To compensate this effect, we propose a new configuration in which we implement the knife edge technique on both parts of the spectrum at the same time. Finally in the computer, we process the holograms to build one complete without deformation. This hologram is used to recover the wave front at different planes without the influence of the conjugate image.

  18. Using electrospray-assisted laser desorption/ionization mass spectrometry to characterize organic compounds separated on thin-layer chromatography plates.

    PubMed

    Lin, Shu-Yao; Huang, Min-Zong; Chang, Hui-Chiu; Shiea, Jentaie

    2007-11-15

    Electrospray-assisted laser desorption/ionization (ELDI), an ionization method that combines laser desorption and electrospray ionization (ESI), can be used under ambient conditions to characterize organic compounds (including FD&C dyes, amines, extracts of a drug tablet) separated in the central track on a thin-layer chromatography (TLC) plate coated with either reversed-phase C18 particles or normal-phase silica gel. After drying, the TLC plate was placed on an acrylic sample holder set in front of the sampling skimmer of an ion trap mass analyzer. The chemicals at the center of the TLC plate were analyzed by pushing the sample holder into the path of a laser beam with a syringe pump. The molecules in the sample spot were desorbed by continuously irradiating the surface of the TLC plate with a pulsed nitrogen laser. Then, the desorbed sample molecules entered an ESI plume where they were ionized through the reactions with the charged species (including protons, hydronium ions and their cluster ions, solvent ions, and charged droplets) generated by electrospraying a methanol/water solution. MS/MS analyses were also performed to further characterize the analytes. The detection limit of TLC/ELDI/MS is approximately 10(-6) M. This was evaluated by using FD&C red dye as the standard. A linear relationship was found for the calibration curve with the concentration of FD&C red dye ranged from 10(-3) to 10(-6) M. PMID:17929897

  19. Investigation of the separated region ahead of three-dimensional protuberances on plates and cones in hypersonic flows with laminar boundary layers

    NASA Astrophysics Data System (ADS)

    Kumar, C. S.; Singh, T.; Reddy, K. P. J.

    2014-12-01

    Heat transfer rate and pressure measurements were made upstream of surface protuberances on a flat plate and a sharp cone subjected to hypersonic flow in a conventional shock tunnel. Heat flux was measured using platinum thin-film sensors deposited on macor substrate and the pressure measurements were made using fast acting piezoelectric sensors. A distinctive hot spot with highest heat flux was obtained near the foot of the protuberance due to heavy vortex activity in the recirculating region. Schlieren flow visualization was used to capture the shock structures and the separation distance ahead of the protrusions was quantitatively measured for varying protuberance heights. A computational analysis was conducted on the flat plate model using commercial computational fluid dynamics software and the obtained trends of heat flux and pressure were compared with the experimental observation. Experiments were also conducted by physically disturbing the laminar boundary layer to check its effect on the magnitude of the hot spot heat flux. In addition to air, argon was also used as test gas so that the Reynolds number can be varied.

  20. Simple refractometer based on in-line fiber interferometers

    NASA Astrophysics Data System (ADS)

    Esteban, Ó.; Martínez Manuel, R.; Shlyagin, M. G.

    2015-09-01

    A very simple but accurate optical fiber refractometer based on the Fresnel reflection in the fiber tip and two in-line low-reflective mirrors for light intensity referencing is reported. Each mirror was generated by connecting together 2 fiber sections with FC/PC and FC/APC connectors using the standard FC/PC mating sleeve. For the sensor interrogation, a standard DFB diode laser pumped with a sawtooth-wave current was used. A resolution of 6 x 10-4 was experimentally demonstrated using different liquids. A simple sensor construction and the use of low cost components make the reported system interesting for many applications.

  1. PMD tolerant nonlinear compensation using in-line phase conjugation.

    PubMed

    McCarthy, M E; Al Kahteeb, M A Z; Ferreira, F M; Ellis, A D

    2016-02-22

    In this paper, we numerically investigate the impact of polarisation mode dispersion on the efficiency of compensation of nonlinear transmission penalties for systems employing one of more inline phase conjugation devices. We will show that reducing the spacing between phase conjugations allows for significantly improved performance in the presence polarisation mode dispersion or a significant relaxation in the acceptable level of polarization mode dispersion. We show that these results are consistent with previously presented full statistical analysis of nonlinear transmission appropriately adjusted for the reduced section length undergoing compensation. PMID:26906997

  2. Final Technical Report - In-line Uranium Immunosensor

    SciTech Connect

    Blake, Diane A.

    2006-07-05

    In this project, personnel at Tulane University and Sapidyne Instruments Inc. developed an in-line uranium immunosensor that could be used to determine the efficacy of specific in situ biostimulation approaches. This sensor was designed to operate autonomously over relatively long periods of time (2-10 days) and was able to provide near real-time data about uranium immobilization in the absence of personnel at the site of the biostimulation experiments. An alpha prototype of the in-line immmunosensor was delivered from Sapidyne Instruments to Tulane University in December of 2002 and a beta prototype was delivered in November of 2003. The beta prototype of this instrument (now available commercially from Sapidyne Instruments) was programmed to autonomously dilute standard uranium to final concentrations of 2.5 to 100 nM (0.6 to 24 ppb) in buffer containing a fluorescently labeled anti-uranium antibody and the uranium chelator, 2,9-dicarboxyl-1,10-phenanthroline. The assay limit of detection for hexavalent uranium was 5.8 nM or 1.38 ppb. This limit of detection is well below the drinking water standard of 30 ppb recently promulgated by the EPA. The assay showed excellent precision; the coefficients of variation (CV’s) in the linear range of the assay were less than 5% and CV’s never rose above 14%. Analytical recovery in the immunosensors-based assay was assessed by adding variable known quantities of uranium to purified water samples. A quantitative recovery (93.75% - 108.17%) was obtained for sample with concentrations from 7.5 to 20 nM (2-4.75 ppb). In August of 2005 the sensor was transported to Oak Ridge National Laboratory, for testing of water samples at the Criddle test site (see Wu et al., Environ. Sci. Technol. 40:3978-3985 2006 for a description of this site). In this first on-site test, the in-line sensor was able to accurately detect changes in the concentrations of uranium in effluent samples from this site. Although the absolute values for the

  3. 36 CFR 13.916 - Use of roller skates, skateboards, roller skis, in-line skates, and similar devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., skateboards, roller skis, in-line skates, and similar devices. 13.916 Section 13.916 Parks, Forests, and..., skateboards, roller skis, in-line skates, and similar devices. The use of roller skates, skateboards, roller skis, in-line skates, and similar devices is prohibited— (a) On the Savage River Loop Trail; the...

  4. 36 CFR 13.916 - Use of roller skates, skateboards, roller skis, in-line skates, and similar devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., skateboards, roller skis, in-line skates, and similar devices. 13.916 Section 13.916 Parks, Forests, and..., skateboards, roller skis, in-line skates, and similar devices. The use of roller skates, skateboards, roller skis, in-line skates, and similar devices is prohibited— (a) On the Savage River Loop Trail; the...

  5. 36 CFR 13.916 - Use of roller skates, skateboards, roller skis, in-line skates, and similar devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., skateboards, roller skis, in-line skates, and similar devices. 13.916 Section 13.916 Parks, Forests, and..., skateboards, roller skis, in-line skates, and similar devices. The use of roller skates, skateboards, roller skis, in-line skates, and similar devices is prohibited— (a) On the Savage River Loop Trail; the...

  6. 36 CFR 13.916 - Use of roller skates, skateboards, roller skis, in-line skates, and similar devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., skateboards, roller skis, in-line skates, and similar devices. 13.916 Section 13.916 Parks, Forests, and..., skateboards, roller skis, in-line skates, and similar devices. The use of roller skates, skateboards, roller skis, in-line skates, and similar devices is prohibited— (a) On the Savage River Loop Trail; the...

  7. 36 CFR 13.916 - Use of roller skates, skateboards, roller skis, in-line skates, and similar devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., skateboards, roller skis, in-line skates, and similar devices. 13.916 Section 13.916 Parks, Forests, and..., skateboards, roller skis, in-line skates, and similar devices. The use of roller skates, skateboards, roller skis, in-line skates, and similar devices is prohibited— (a) On the Savage River Loop Trail; the...

  8. The Impact of Surface Friction on Boundary Layer Separation for Different Mountain Flow Regimes: An Analysis Based on Large-Eddy-Simulations

    NASA Astrophysics Data System (ADS)

    Sachsperger, Johannes; Serafin, Stefano; Grubišić, Vanda

    2014-05-01

    Boundary layer separation (BLS) may occur when a strong external adverse pressure gradient force is imposed on the boundary layer flow, leading to detachment of streamlines from the surface due to a strong deceleration of the flow within the boundary layer. This process commonly occurs at the salient edge of very sharp obstacles. In stably stratified flows pressure perturbations strong enough to cause BLS can also be induced by internal gravity waves. A well-known phenomenon related to wave-induced BLS is that of atmospheric rotors that form on the lee side of mountain ranges. Rotors are boundary-layer zones characterized by strong turbulence, surface wind reversals, large values of spanwise vorticity and neutral stability. Due to the high intensity of turbulence, atmospheric rotors are known to pose a hazard for general aviation and road traffic and can significantly impact the energy yield of wind parks in mountainous terrain. Hence, the onset of BLS and formation of rotors have been extensively investigated in recent years. However, only a few systematic studies of the processes involved in the formation of rotors are available in the literature. In this study, the CM1 model is used to explore the impact of different mountain flow regimes (from hydrostatic to non-hydrostatic and from weakly to strongly non-linear) and the surface exchange coefficient for momentum on the size and strength of rotors. In addition to that, a feedback mechanism of BLS onto the larger-scale flow is investigated. The results show that the governing flow regime has a strong impact on the strength and size of atmospheric rotors, whereas friction mainly influences the rotor interior structure. The most intense rotors, as measured by the strength of surface reversed flow, are found to occur in strongly non-linear and non-hydrostatic flows. The largest rotors instead do not necessarily occur in the strongest non-linear flow regime, in which the largest amplitudes of mountain waves are to be

  9. Inline quality prognosis of material condition induced process variations

    NASA Astrophysics Data System (ADS)

    Heinzler, Felix A.; Wortberg, Johannes

    2014-05-01

    The main variation in a good quality production are induced by material condition. Processing technical polymers like PA, ABS or PBT possible influences are residual moisture conditions of the material or minor variations of raw material charges. Small changes in the material properties are difficult to detect at first quality controls and can be within the property tolerances. But even these small differences cause defects. The effects range from viscosity variations to varied crystalline properties. The influence of material properties on the processing have to be detected inline and combined with material analysis to a quality prognosis. The equipped sensors at injection molding machines enable an adequate process performance. The recently available solutions for power consumption monitoring enhance the available process control opportunities. Because of the high process speed of injection molding machines, the required sampling rate has to be minimal 500 Hz. A setup of high bandwidth data processing linked to the machine control enables precise characterization of the production. Identified index numbers, energetic data and characteristic development of measured process figures enable a high resolution detection of material induced variations. This prognosis enables inline classification of the produced parts and a compensation by correlating quality requirements with adjusted filling and packing parameters.

  10. Towards Fast In-line Measurement of Water Activity

    NASA Astrophysics Data System (ADS)

    Nielsen, J.; Andreasen, M. B.; Pedersen, M.; Rasmussen, M. K.

    2015-03-01

    Water activity is widely used as a key parameter in controlling the quality of food and feed products, among others. For determining the water activity, the material is sampled from the manufacturing process and measured in the laboratory with water activity analyzers. The sampling procedure can lead to non-representative measurements, the measurement process is time consuming, and much of the produced material may be wasted before the measurement results are available. To reduce waste and to be able to optimize production processes, industry requires in-line measurement of relevant quality determining parameters, hereunder the water activity. In cooperation with a manufacturer of systems for automatic in-line sampling and measurement of moisture, density, and the size of items, a project was defined to also enable the manufacturer's existing products to perform automatic measurement of the water activity in a sample. The aim was to develop a measurement system with the ability to operate in an industrial environment, which in the end would increase the measurement speed significantly and minimize the problems related to the handling of samples. In the paper the selection and characterization of the sensors, the design of a measurement chamber, and various issues of modeling and methods to reduce measurement time are discussed. The paper also presents water activity measurements obtained from food and feed products with the system, and shows that reliable results can be obtained in a few minutes with a proper design of the measurement chamber and selection of a model.

  11. In-line particle field holography at Pegasus

    SciTech Connect

    Sorenson, D.S.; Obst, A.; King, N.S.P.

    1995-09-01

    An in-line holographic imaging system has been developed for hydrodynamic experiments at the Pegasus facility located at Los Alamos National Laboratory. Holography offers the unique capability to record distributions of particles over a three dimensional volume. The system to be discussed is used to measure particle distributions of ejecta emitted after a cylindrical aluminum liner (5.0 cm in diameter, 2.0 cm high) impacts a target (3.0 cm in diameter). The ejecta emerges from the target traveling up to 7mm/{micro}s and moves toward the axial center of the system where the holographic imaging is performed. In-line holography is particularly suited for the Pegasus pulsed power facility where the geometry restrictions make off axis holography impractical. In order to record the fast moving particles a frequency-doubled Nd:-YAG laser system has been implemented which produces a 80 ps 20 millijoule pulse at 532 nm. An optical relay system composed of a Fourier optical lens pair has been developed which is placed 4.0 cm from the center of the region of interest. This relay lens pair forms an intermediate image 32 cm from the object plane and the hologram is placed 4cm downstream of the intermediate image. The holographic system and resolution capability are discussed.

  12. In-line ultrasonic monitoring of waste slurry suspended solids

    SciTech Connect

    Chien, H.-T.; Sheen, S.-H.; Raptis, A. C.

    2000-05-25

    During the transport of tank waste, it is very important to quantitatively measure the percent solids concentration (PSC) of the waste, which indicates the flow conditions and the extent of solids settling. At Argonne National Laboratory, an in-line, real-time, a nonintrusive ultrasonic monitoring system has been developed to measure the PSC and flow density of tank waste by measuring sound velocity and attenuation in the flow. This system consists of a pair of longitudinal transducers bonded to waveguides on the opposite sides of the pipe and operating at IMHz simultaneously in pulse-and-echo and pitch-and-catch modes. The PSC measurement is provided by attenuation, while the density measurement is calculated by impedance and sound velocity. A thermocouple is attached to one of the waveguides for automatic temperature correction of the measurements. This system was one of four evaluated for in-line measurement of slurry at Oak Ridge National Laboratory in 1998. The results indicate that the measurements are in good agreement with a Coriolis meter and that the system can be used to monitor PSC up to 40 wt.%. However, the system is greatly affected by entrained air bubbles within the solid flow during Puisair mixing. A different mixing mechanism will solve this problem.

  13. Real-time data processing for in-line monitoring of a pharmaceutical coating process by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Markl, Daniel; Ziegler, Jakob; Hannesschläger, Günther; Sacher, Stephan; Buchsbaum, Andreas; Leitner, Michael; Khinast, Johannes G.

    2014-05-01

    Coating of tablets is a widely applied unit operation in the pharmaceutical industry. Thickness and uniformity of the coating layer are crucial for efficacy as well as for compliance. Not only due to different initiatives it is thus essential to monitor and control the coating process in-line. Optical coherence tomography (OCT) was already shown in previous works to be a suitable candidate for in-line monitoring of coating processes. However, to utilize the full potential of the OCT technology an automatic evaluation of the OCT measurements is essential. The automatic evaluation is currently implemented in MATLAB and includes several steps: (1) extraction of features of each A-scan, (2) classification of Ascan measurements based on their features, (3) detection of interfaces (air/coating and coating/tablet core), (4) correction of distortions due to the curvature of the bi-convex tablets and the oblique orientation of the tablets, and (5) determining the coating thickness. The algorithm is tested on OCT data acquired by moving the sensor head of the OCT system across a static tablet bed. The coating thickness variations of single tablets (i.e., intra-tablet coating variability) can additionally be analyzed as OCT allows the measurement of the coating thickness on multiple displaced positions on one single tablet. Specifically, the information about those parameters emphasizes the high capability of the OCT technology to improve process understanding and to assure a high product quality.

  14. Effect of Reynolds Number and Periodic Unsteady Wake Flow Condition on Boundary Layer Development, Separation, and Re-attachment along the Suction Surface of a Low Pressure Turbine Blade

    NASA Technical Reports Server (NTRS)

    Ozturk, B.; Schobeiri, M. T.; Ashpis, David E.

    2005-01-01

    The paper experimentally studies the effects of periodic unsteady wake flow and different Reynolds numbers on boundary layer development, separation and re-attachment along the suction surface of a low pressure turbine blade. The experimental investigations were performed on a large scale, subsonic unsteady turbine cascade research facility at Turbomachinery Performance and Flow Research Laboratory (TPFL) of Texas A&M University. The experiments were carried out at Reynolds numbers of 110,000 and 150,000 (based on suction surface length and exit velocity). One steady and two different unsteady inlet flow conditions with the corresponding passing frequencies, wake velocities, and turbulence intensities were investigated. The reduced frequencies chosen cover the operating range of LP turbines. In addition to the unsteady boundary layer measurements, surface pressure measurements were performed. The inception, onset, and the extent of the separation bubble information collected from the pressure measurements were compared with the hot wire measurements. The results presented in ensemble-averaged, and the contour plot forms help to understand the physics of the separation phenomenon under periodic unsteady wake flow and different Reynolds number. It was found that the suction surface displayed a strong separation bubble for these three different reduced frequencies. For each condition, the locations defining the separation bubble were determined carefully analyzing and examining the pressure and mean velocity profile data. The location of the boundary layer separation was dependent of the Reynolds number. It is observed that starting point of the separation bubble and the re-attachment point move further downstream by increasing Reynolds number from 110,000 to 150,000. Also, the size of the separation bubble is smaller when compared to that for Re=110,000.

  15. Separating liquid and solid products of liquefaction of coal or like carbonaceous materials

    DOEpatents

    Malek, John M.

    1979-06-26

    Slurryform products of coal liquefaction are treated with caustic soda in presence of H.sub.2 O in an inline static mixer and then the treated product is separated into a solids fraction and liquid fractions, including liquid hydrocarbons, by gravity settling preferably effected in a multiplate settling separator with a plurality of settling spacings.

  16. Safety shutdown separators

    DOEpatents

    Carlson, Steven Allen; Anakor, Ifenna Kingsley; Farrell, Greg Robert

    2015-06-30

    The present invention pertains to electrochemical cells which comprise (a) an anode; (b) a cathode; (c) a solid porous separator, such as a polyolefin, xerogel, or inorganic oxide separator; and (d) a nonaqueous electrolyte, wherein the separator comprises a porous membrane having a microporous coating comprising polymer particles which have not coalesced to form a continuous film. This microporous coating on the separator acts as a safety shutdown layer that rapidly increases the internal resistivity and shuts the cell down upon heating to an elevated temperature, such as 110.degree. C. Also provided are methods for increasing the safety of an electrochemical cell by utilizing such separators with a safety shutdown layer.

  17. Accurate in-line CD metrology for nanometer semiconductor manufacturing

    NASA Astrophysics Data System (ADS)

    Perng, Baw-Ching; Shieh, Jyu-Horng; Jang, S.-M.; Liang, M.-S.; Huang, Renee; Chen, Li-Chien; Hwang, Ruey-Lian; Hsu, Joe; Fong, David

    2006-03-01

    The need for absolute accuracy is increasing as semiconductor-manufacturing technologies advance to sub-65nm nodes, since device sizes are reducing to sub-50nm but offsets ranging from 5nm to 20nm are often encountered. While TEM is well-recognized as the most accurate CD metrology, direct comparison between the TEM data and in-line CD data might be misleading sometimes due to different statistical sampling and interferences from sidewall roughness. In this work we explore the capability of CD-AFM as an accurate in-line CD reference metrology. Being a member of scanning profiling metrology, CD-AFM has the advantages of avoiding e-beam damage and minimum sample damage induced CD changes, in addition to the capability of more statistical sampling than typical cross section metrologies. While AFM has already gained its reputation on the accuracy of depth measurement, not much data was reported on the accuracy of CD-AFM for CD measurement. Our main focus here is to prove the accuracy of CD-AFM and show its measuring capability for semiconductor related materials and patterns. In addition to the typical precision check, we spent an intensive effort on examining the bias performance of this CD metrology, which is defined as the difference between CD-AFM data and the best-known CD value of the prepared samples. We first examine line edge roughness (LER) behavior for line patterns of various materials, including polysilicon, photoresist, and a porous low k material. Based on the LER characteristics of each patterning, a method is proposed to reduce its influence on CD measurement. Application of our method to a VLSI nanoCD standard is then performed, and agreement of less than 1nm bias is achieved between the CD-AFM data and the standard's value. With very careful sample preparations and TEM tool calibration, we also obtained excellent correlation between CD-AFM and TEM for poly-CDs ranging from 70nm to 400nm. CD measurements of poly ADI and low k trenches are also

  18. Layered plasma polymer composite membranes

    DOEpatents

    Babcock, W.C.

    1994-10-11

    Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is [>=]2 and is the number of selective layers. 2 figs.

  19. Microfabrication, separations, and detection by mass spectrometry on ultrathin-layer chromatography plates prepared via the low-pressure chemical vapor deposition of silicon nitride onto carbon nanotube templates.

    PubMed

    Kanyal, Supriya S; Häbe, Tim T; Cushman, Cody V; Dhunna, Manan; Roychowdhury, Tuhin; Farnsworth, Paul B; Morlock, Gertrud E; Linford, Matthew R

    2015-07-24

    Microfabrication of ultrathin-layer chromatography (UTLC) plates via conformal deposition of silicon nitride by low-pressure chemical vapor deposition onto patterned carbon nanotube (CNT) scaffolds was demonstrated. After removal of the CNTs and hydroxylation, the resulting UTLC phase showed no expansion or distortion of their microfeatures and the absence/reduction of remaining nitrogenic species. Developing time of a mixture of lipophilic dyes on this UTLC plates was 86% shorter than on high-performance thin-layer chromatography (HPTLC) plates. A water-soluble food dye mixture was also separated resulting in low band broadening and reduced developing time compared to HPTLC. For the latter example, mobile phase optimization on a single UTLC plate consisted of 14 developments with different mobile phases, each preceded by a plate prewashing step. The same plate was again reused for additional 11 separations under varying conditions resulting in a development procedure with a mean separation efficiency of 233,000theoretical plates/m and a reduced mobile phase consumption of only 400μL. This repeated use proved the physical robustness of the ultrathin layer and its resistance to damage. The layer was highly suited for hyphenation to ambient mass spectrometry, including desorption electrospray ionization (DESI) mass spectrometry imaging and direct analysis in real time (DART) mass spectrometry. PMID:26065571

  20. IEMDC - In-Line Electric Motor Driven Compressor

    SciTech Connect

    Michael J. Crowley

    2004-03-31

    This report covers the fifth quarter (01/01/04 to 03/31/04) of the In-Line Electric Motor Driven Compressor (IEMDC) project. Design efforts on the IEMDC continued with compressor efforts focused on performing aerodynamic analyses. These analyses were conducted using computational fluid dynamics. Compressor efforts also entailed developing mechanical designs of components through the use of solid models and working on project deliverables. Electric motor efforts focused on the design of the magnetic bearing system, motor pressure housing, and the motor-compressor interface. The mechanical evaluation of the main interface from both the perspective of the compressor manufacturer and electric motor manufacturer indicates that an acceptable design has been achieved. All mechanical and aerodynamic design efforts have resulted in considerable progress being made towards the completion of the compressor and electric motor design and towards the successful completion of the IEMDC unit.

  1. Lensfree in-line holographic detection of bacteria

    NASA Astrophysics Data System (ADS)

    Poher, V.; Allier, C. P.; Coutard, J. G.; Hervé, L.; Dinten, J. M.

    2011-07-01

    Due to low light scattering, bacteria are difficult to detect using lensless imaging systems. In order to detect individual bacteria, we report a method based on a thin wetting film imaging that produces a micro-lens effect on top of each bacterium when the sample dries up. The imaging using a high-end CMOS sensor is combined with an in-line holographic reconstruction to improve positive detection rate up to 95% with micron-sized beads at high density of ~103 objects/mm2. The system allows detecting from single bacterium to densely packed objects (103 bacteria/μl) within 10μl sample. As an example, E.coli, Bacillus subtilis and Bacillus thuringiensis, has been successfully detected with strong signal to noise ratio across a 24mm2 field of view.

  2. Alternative method for monitoring an in-line CD SEM

    NASA Astrophysics Data System (ADS)

    Herrera, Pedro P.; Dick, Susan A.; Allgair, John A.

    1997-07-01

    Semiconductor manufacturers must ensure that their in-line critical dimension scanning electron microscopes (CD-SEMs) are providing precise and reliable data on a daily basis. As with other process equipment, tool stability and production worthiness is determined by a daily qualification procedure that involves measuring a reference, etched wafer's linewidth and comparing those results to a set target mean. However, repeated exposure to a SEM creates an unacceptable increase in the measured feature's CD. This increase can be disruptive to tool qualification, requires the introduction of new reference wafers, and ultimately limits the tool's availability to production. A new method for daily qualification using a rotating daily job scheme has been developed and employed for monitoring multiple systems at Motorola MOS-13/APRDL. This new procedure allows for better statistical process control, increase the reference wafer's useful life, and provides an easier method of monitoring the tool throughout its lifetime.

  3. In-line chemical sensor deployment in a tritium plant

    SciTech Connect

    Wright, J.S.; Hope, D.T.; Torres, R.D.; Peters, B.; Tovo, L.L.

    2015-03-15

    The Savannah River Tritium Plant (TP) relies on well understood but aging sensor technology for process gas analysis. The use of alternative sensing and detection technologies for in-line and real-time analysis would aid process control and optimization. The TP upgrading follows a 2-phase projects. In the first phase, TP sensing requirements were determined by a team of process experts. Meanwhile, Savannah River National Laboratory sensor experts identified candidate technologies and related them to the TP processing requirements. The resulting road-map links the candidate technologies to actual plant needs. In the second phase an instrument demonstration station was established within a TP glove box in order to provide accurate assessments of how a candidate sensor technology would perform in a contaminated process environment.

  4. Embedded Doppler system for industrial in-line rheometry.

    PubMed

    Ricci, Stefano; Liard, Maxime; Birkhofer, Beat; Lootens, Didier; Bruhwiler, Armin; Tortoli, Piero

    2012-07-01

    Rheological fluid behavior characterization is crucial for the industrial production of cosmetics, food, pharmaceutics, adhesive, sealants, etc. For example, the measurement of specific rheological features at every step of the production chain is critical for product quality control. Such measurements are often limited to laboratory tests on product specimens because of technical difficulties. In this work, we present an embedded system suitable for in-line rheometric evaluation of highly filled polyurethane-based adhesives. This system includes an ultrasound front-end and a digital signal processing section integrated in a low-cost field-programmable gate array. The system measures the real-time velocity profile developed in the pipe by the fluid, employing a Doppler multigate technique. The high-resolution velocity profile, combined with a pressure drop measurement, allows an accurate evaluation of the flow consistency index, K, and the flow behavior index, n, of the interrogated fluid. PMID:22828835

  5. DOT`s perspective on in-line inspection

    SciTech Connect

    Ulrich, L.W.

    1996-08-01

    The Department of Transportation and its Office of Pipeline Safety have been involved with in-line inspection (ILI) pigs since the construction of the Alaska crude oil pipeline in the early 1970s. Two Congressionally mandated reports concerning ILI pigs and a regulation requiring new and replaced pipe and components to be designed and constructed to accommodate ILI pigs have been issued by the Department. Although there is no present federal requirement to run ILI pigs, they are required by the Office of Pipeline Safety in selected compliance cases. The Department will continue to use ILI pigs in compliance cases. It also supports future ILI pig research, and the use of ILI pig surveys incorporated in any pipeline operator`s future risk management plans developed as safety alternatives to the established pipeline safety regulations. The Department also in the future may require ILI pigs to be run on some pipelines.

  6. In-line 90 nm Technology Gate Oxide Nitrogen Monitoring With Non-Contact Electrical Technique

    NASA Astrophysics Data System (ADS)

    Pic, Nicolas; Polisski, Gennadi; Paire, Emmanuel; Rizzo, Véronique; Grosjean, Catherine; Bortolotti, Benjamin; D'Amico, John; Cabuil, Nicolas

    2009-09-01

    The continuous race to reduce the dimensions of IC components has lead to the introduction of Nitrogen in the thin gate oxide layer in order to increase the dielectric constant and to improve the gate dielectric properties. It is mandatory to apply in-line monitoring to control the amount of Nitrogen to ensure that electrical behavior is correct over time. Historically, this monitoring was performed by measuring the delay to reoxidation (D2R) with an ellipsometer. But, this method is not suitable in production as it is depending on both initial oxidation and reoxidation reproducibility, which implies implementing dedicated Statistical Process Control (SPC) monitoring at these two specific processing steps. We are here presenting an alternative method to D2R for 90 nm Technology gate oxide grown by Rapid Thermal Process (RTP). Applying a non-contact Metrology technique, which couples Kelvin probe surface voltage measurement with surface Corona deposition, directly after the nitridation step, the interface trapped charge (QIT) is obtained by integration of the interface state density over the space charge region. In summary, this electrical non-contact monitoring is more sensitive to the Nitrogen content compared to ellipsometer measurement after nitridation or after D2R, less sensitive compared to D2R to any initial oxide variation, and it allows simplification of the qualification procedure at this process step by skipping the reoxidation.

  7. In-line holography and coherent diffractive imaging with x-ray waveguides

    SciTech Connect

    De Caro, L.; Giannini, C.; Guagliardi, A.; Mocuta, C.; Metzger, T. H.; Cedola, A.; Burkeeva, I.; Lagomarsino, S.

    2008-02-15

    A Fresnel coherent diffraction imaging experiment with hard x rays is here presented, using two planar crossed waveguides as optical elements, leading to a virtual pointlike source. The coherent wave field obtained with this setup is used to illuminate a micrometric single object having the shape of a butterfly. A digital two-dimensional in-line holographic reconstruction of the unknown object at low resolution (200 nm) has been obtained directly via fast Fourier transform (FFT) of the raw data. The object and its twin image are well separated because suitable geometrical conditions are satisfied. A good estimate of the incident wave field phase has been extracted directly from the FFT of the raw data. A partial object reconstruction with 50 nm spatial resolution was achieved by fast iterative phase retrieval, the major limitation for a full reconstruction being the nonideal structure of the guided beam. The method offers a route for fast and reliable phase retrieval in x-ray coherent diffraction.

  8. In-line polarization rotator based on the quantum-optical analogy.

    PubMed

    Chen, Lei; Qu, Ke-Nan; Shen, Heng; Zhang, Wei-Gang; Chou, Keng C; Liu, Qian; Yan, Tie-Yi; Wang, Biao; Wang, Song

    2016-05-01

    An in-line polarization rotator (PR) is proposed based on the quantum-optical analogy (QOA). The proposed PR possesses an auxiliary E7 liquid crystal (LC) waveguide in the vicinity of the single-mode fiber (SMF) core. Because of the matched core size, the PR demonstrates good compatibility with the established backbone networks which are composed of conventional SMFs. With optimized parameters for the auxiliary waveguide, the PR offers a near 100% polarization conversion efficiency at the 1550 nm band with a bandwidth of ∼30  nm, a length of ∼4625.9  μm with a large tolerance of ∼550  μm, and a tolerance of the input light polarization angle and rotation angle of the E7 LC of ∼π/30 and ∼π/36  rad, respectively. The performance was verified by the full-vector finite-element method. The proposed PR can be easily fabricated based on the existing photonics crystal fiber manufacturing process, making it a potentially inexpensive device for applications in modern communication systems. Moreover, the QOA, compared with the previous supermode-theory design method, allows a designer to consider several waveguides separately. Therefore, various unique characteristics can be met simultaneously which is consistent with the trend of modern fiber design. PMID:27128087

  9. In-line holography and coherent diffractive imaging with x-ray waveguides

    NASA Astrophysics Data System (ADS)

    de Caro, L.; Giannini, C.; Pelliccia, D.; Mocuta, C.; Metzger, T. H.; Guagliardi, A.; Cedola, A.; Burkeeva, I.; Lagomarsino, S.

    2008-02-01

    A Fresnel coherent diffraction imaging experiment with hard x rays is here presented, using two planar crossed waveguides as optical elements, leading to a virtual pointlike source. The coherent wave field obtained with this setup is used to illuminate a micrometric single object having the shape of a butterfly. A digital two-dimensional in-line holographic reconstruction of the unknown object at low resolution (200nm) has been obtained directly via fast Fourier transform (FFT) of the raw data. The object and its twin image are well separated because suitable geometrical conditions are satisfied. A good estimate of the incident wave field phase has been extracted directly from the FFT of the raw data. A partial object reconstruction with 50nm spatial resolution was achieved by fast iterative phase retrieval, the major limitation for a full reconstruction being the nonideal structure of the guided beam. The method offers a route for fast and reliable phase retrieval in x-ray coherent diffraction.

  10. In-Line Fiber Optic Interferometric Sensors in Single-Mode Fibers

    PubMed Central

    Zhu, Tao; Wu, Di; Liu, Min; Duan, De-Wen

    2012-01-01

    In-line fiber optic interferometers have attracted intensive attention for their potential sensing applications in refractive index, temperature, pressure and strain measurement, etc. Typical in-line fiber-optic interferometers are of two types: Fabry-Perot interferometers and core-cladding-mode interferometers. It's known that the in-line fiber optic interferometers based on single-mode fibers can exhibit compact structures, easy fabrication and low cost. In this paper, we review two kinds of typical in-line fiber optic interferometers formed in single-mode fibers fabricated with different post-processing techniques. Also, some recently reported specific technologies for fabricating such fiber optic interferometers are presented. PMID:23112608

  11. In-line phase-contrast imaging based on Tsinghua Thomson scattering x-ray source.

    PubMed

    Zhang, Zhen; Du, Yingchao; Yan, Lixin; Hua, Jianfei; Yang, Jin; Xiao, Yongshun; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

    2014-08-01

    Thomson scattering x-ray sources can produce ultrashort, energy tunable x-ray pulses characterized by high brightness, quasi-monochromatic, and high spatial coherence, which make it an ideal source for in-line phase-contrast imaging. We demonstrate the capacity of in-line phase-contrast imaging based on Tsinghua Thomson scattering X-ray source. Clear edge enhancement effect has been observed in the experiment. PMID:25173262

  12. Transient hydrodynamics of in-line valves in viscoelastic pressurized pipes: long-period analysis

    NASA Astrophysics Data System (ADS)

    Meniconi, Silvia; Brunone, Bruno; Ferrante, Marco; Massari, Christian

    2012-07-01

    The literature contains few reports devoted to the analysis of the effects of a partially closed in-line valve on the characteristics of transients in viscoelastic pressurized pipes. In this paper a contribution to the analysis of the long-period behavior of pressure is offered from both the experimental and numerical modeling point of view. In the first part, laboratory tests and the related results—noticeably extensive with respect to the existing literature—are examined. More precisely, the dependance of the damping of the dimensionless pressure maximum values on the initial conditions and in-line valve local head loss coefficient is shown. In the second part, a 1-D numerical model is developed by determining its parameters within a physically based procedure. Model parameters are obtained by considering transients in a constant-diameter pipe (single pipe) and then exported to the case of pipes with a partially closed in-line valve (in-line valve pipe). Moreover, particular attention is devoted to the modalities of specifying boundary conditions. In particular, the quasi-steady-state approach is followed for determining the transient local head loss due to the partially closed in-line valve and the actual supply conditions and characteristics of the maneuver are taken into account. Finally, the effect of unsteady friction and viscoelasticity is examined in both single and in-line valve pipes.

  13. Flow-injection in-line complexation for ion-pair reversed phase high performance liquid chromatography of some metal-4-(2-pyridylazo) resorcinol chelates.

    PubMed

    Srijaranai, Supalax; Chanpaka, Saiphon; Kukusamude, Chutima; Grudpan, Kate

    2006-02-28

    Flow injection (FI) was coupled to ion-pair reversed phase high performance liquid chromatography (IP-RPHPLC) for the simultaneous analysis of some metal-4-(2-pyridylazo) resorcinol (PAR) chelates. A simple reverse flow injection (rFI) set-up was used for in-line complexation of metal-PAR chelates prior to their separation by IP-RPHPLC. The rFI conditions were: injection volume of PAR 85muL, flow rate of metal stream 4.5mLmin(-1), concentration of PAR 1.8x10(-4)molL(-1) and the mixing coil length of 150cm. IP-RPHPLC was carried out using a C(18)muBondapak column with the mobile phase containing 37% acetonitrile, 3.0mmolL(-1) acetate buffer pH 6.0 and 6.2mmolL(-1) tetrabutylammonium bromide (TBABr) at a flow rate of 1.0mLmin(-1) and visible detection at 530 and 440nm. The analysis cycle including in-line complexation and separation by IP-RPHPLC was 16min, which able to separate Cr(VI) and the PAR chelates of Co(II), Ni(II) and Cu(II). PMID:18970520

  14. Tuning the phase separation in La0.325Pr0.3Ca0.375MnO3 using the electric double-layer field effect

    NASA Astrophysics Data System (ADS)

    Cui, Li-Min; Li, Jie; Zhang, Yu; Zhao, Lu; Deng, Hui; Huang, Ke-Qiang; Li, He-Kang; Zheng, Dong-Ning

    2014-09-01

    Electric double-layer field effect experiments were performed on ultrathin films of La0.325Pr0.3Ca0.375MnO3, which is noted for its micrometer-scale phase separation. A clear change of resistance up to 220% was observed and the characteristic metal—insulator transition temperature TP was also shifted. The changes of both the resistance and TP suggest that the electric field induced not only tuning of the carrier density but also rebalancing of the phase separation states. The change of the charge-ordered insulating phase fraction was estimated to be temperature dependent, and a maximum of 16% was achieved in the phase separation regime. This tuning effect was partially irreversible, which might be due to an oxygen vacancy migration that is driven by the huge applied electric field.

  15. Inline electron holography and VEELS for the measurement of strain in ternary and quaternary (In,Al,Ga)N alloyed thin films and its effect on bandgap energy.

    PubMed

    Mánuel, J M; Koch, C T; Özdöl, V B; Sigle, W; VAN Aken, P A; García, R; Morales, F M

    2015-01-01

    We present the use of (1) dark-field inline electron holography for measuring the structural strain, and indirectly obtaining the composition, in a wurtzite, 4-nm-thick InAlGaN epilayer on a AlN/GaN/AlN/GaN multinano-layer heterosystem, and (2) valence electron energy-loss spectroscopy to study the bandgap value of five different, also hexagonal, 20-50-nm-thick InAlGaN layers. The measured strain values were almost identical to the ones obtained by other techniques for similarly grown materials. We found that the biaxial strain in the III-N alloys lowers the bandgap energy as compared to the value calculated with different known expressions and bowing parameters for unstrained layers. By contrast, calculated and experimental values agreed in the case of lattice-matched (almost unstrained) heterostructures. PMID:26372901

  16. Improvements on Digital Inline Holographic PIV for Turbulent Flow Measurement

    NASA Astrophysics Data System (ADS)

    Hong, Jiarong; Toloui, Mostafa; Mallery, Kevin

    2015-11-01

    Among all the 3D PIV techniques used in wall-bounded turbulent flow measurements, digital inline holographic (DIH) PIV provides the highest spatial resolution for near-wall flow diagnostics with low-cost, simple and compact optical set-ups. Despite these advantages, DIH-PIV 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, and expensive computations. These limitations prevent this technique from being widely implemented for high resolution 3D flow measurements. In this study, we present our work on improving holographic particle extraction algorithm with the goal of overcoming some of abovementioned limitations. Our new DIH-PIV processing method has been successfully implemented on multiple experimental cases ranging from 3D flow measurement within a micro-channel to imaging near-wall coherent structures in smooth and rough wall turbulent channel flows. This work is supported by the startup package of Jiarong Hong and the MnDrive Fellowship of Mostafa Toloui from University of Minnesota.

  17. Inline protein A mass spectrometry for characterization of monoclonal antibodies.

    PubMed

    Prentice, Kenneth M; Wallace, Alison; Eakin, Catherine M

    2015-02-17

    Purification of antibodies is an important first step to produce material for in depth characterization of biotherapeutics. To reduce the resource burden incurred by protein purification, we developed a high throughput protein A affinity capture step coupled to inline mass spectrometry (PrA-MS). Our method enables both UV quantitation of antibodies and product characterization of an intact molecule with microgram quantities of material. When purification and analysis are coupled along with the low material demand, PrA-MS is widely applicable to protein characterization and is uniquely advantageous for moieties that rely on molecular stoichiometry. Two model systems were studied using PrA-MS and are presented here: (a) bispecific antibodies (bsAb) and (b) glycan engineered antibodies. In the bsAb samples, hetero- and homodimer species, along with partial molecule, were readily identified and quantified directly from harvested cell culture fluid (HCCF). In the glycan engineered antibodies, fully afucosylated, as well as asymmetrically and symmetrically fucosylated, glycans were identified from HCCF in experiments that utilized a small molecule inhibitor of fucosyltrasferase. The PrA-MS method represents a high throughput alternative to offline purification and product characterization that may be leveraged across the product lifecycle of engineered antibodies to enable rapid development and production of important therapeutics. PMID:25647041

  18. Separator for lithium batteries and lithium batteries including the separator

    SciTech Connect

    Foster, D.L.

    1989-03-14

    A multilayer separator is described for preventing the internal shorting of lithium batteries, the multilayer separator including porous membranes and an electroactive polymeric material contained within the separator layers wherein the polymer is one that will react with any lithium dendrites that could penetrate the separator thus preventing an internal short circuit of the cell.

  19. Method for the separation of the unconjugates and conjugates of chenodeoxycholic acid and deoxycholic acid by two-dimensional reversed-phase thin layer chromatography with methyl beta-cyclodextrin.

    PubMed

    Momose, T; Mure, M; Iida, T; Goto, J; Nambara, T

    1998-06-19

    A simple and efficient method for the separation of individual unconjugated bile acids and their glycine- and taurine-amidated, 3-sulfated, 3-glucosylated and 3-glucuronidated conjugates is described. The method involves the use of a two-dimensional (2D) reversed-phase (RP) high-performance thin-layer chromatographic (HPTLC) technique with methyl beta-cyclodextrin (Me-beta-CD). Five major unconjugated bile acids, chenodeoxycholic acid (CDCA), deoxycholic acid (DCA), ursodeoxycholic acid and lithocholic acid, and their conjugates were examined as the solutes. A high degree of separation of individual bile acids in each homologous series was achieved on a RP-HPTLC plate by developing with aqueous methanol in the first dimension and the same solvent system containing Me-beta-CD in the second dimension. In particular, all of the six 'difficult-to-separate' pairs, unconjugated CDCA and DCA and their conjugated forms with glycine, taurine, sulfuric acid, D-glucose and D-glucuronic acid, were effectively resolved by adding Me-beta-CD in the aqueous mobile phases with the formers having larger mobilities than the latter. The application of this 2D inclusion RP-HPLC method to the separation of glycine-conjugated bile acids in human bile is also described. The present method would be useful for separating and characterizing these bile acids present in biological materials. PMID:9691303

  20. RACORO continental boundary layer cloud investigations. 3. Separation of parameterization biases in single-column model CAM5 simulations of shallow cumulus

    DOE PAGESBeta

    Lin, Wuyin; Liu, Yangang; Vogelmann, Andrew M.; Fridlind, Ann; Endo, Satoshi; Song, Hua; Feng, Sha; Toto, Tami; Li, Zhijin; Zhang, Minghua

    2015-06-19

    Climatically important low-level clouds are commonly misrepresented in climate models. The FAst-physics System TEstbed and Research (FASTER) project has constructed case studies from the Atmospheric Radiation Measurement (ARM) Climate Research Facility's Southern Great Plain site during the RACORO aircraft campaign to facilitate research on model representation of boundary-layer clouds. This paper focuses on using the single-column Community Atmosphere Model version 5 (SCAM5) simulations of a multi-day continental shallow cumulus case to identify specific parameterization causes of low-cloud biases. Consistent model biases among the simulations driven by a set of alternative forcings suggest that uncertainty in the forcing plays only amore » relatively minor role. In-depth analysis reveals that the model's shallow cumulus convection scheme tends to significantly under-produce clouds during the times when shallow cumuli exist in the observations, while the deep convective and stratiform cloud schemes significantly over-produce low-level clouds throughout the day. The links between model biases and the underlying assumptions of the shallow cumulus scheme are further diagnosed with the aid of large-eddy simulations and aircraft measurements, and by suppressing the triggering of the deep convection scheme. It is found that the weak boundary layer turbulence simulated is directly responsible for the weak cumulus activity and the simulated boundary layer stratiform clouds. Increased vertical and temporal resolutions are shown to lead to stronger boundary layer turbulence and reduction of low-cloud biases.« less

  1. RACORO continental boundary layer cloud investigations. 3. Separation of parameterization biases in single-column model CAM5 simulations of shallow cumulus

    SciTech Connect

    Lin, Wuyin; Liu, Yangang; Vogelmann, Andrew M.; Fridlind, Ann; Endo, Satoshi; Song, Hua; Feng, Sha; Toto, Tami; Li, Zhijin; Zhang, Minghua

    2015-06-19

    Climatically important low-level clouds are commonly misrepresented in climate models. The FAst-physics System TEstbed and Research (FASTER) project has constructed case studies from the Atmospheric Radiation Measurement (ARM) Climate Research Facility's Southern Great Plain site during the RACORO aircraft campaign to facilitate research on model representation of boundary-layer clouds. This paper focuses on using the single-column Community Atmosphere Model version 5 (SCAM5) simulations of a multi-day continental shallow cumulus case to identify specific parameterization causes of low-cloud biases. Consistent model biases among the simulations driven by a set of alternative forcings suggest that uncertainty in the forcing plays only a relatively minor role. In-depth analysis reveals that the model's shallow cumulus convection scheme tends to significantly under-produce clouds during the times when shallow cumuli exist in the observations, while the deep convective and stratiform cloud schemes significantly over-produce low-level clouds throughout the day. The links between model biases and the underlying assumptions of the shallow cumulus scheme are further diagnosed with the aid of large-eddy simulations and aircraft measurements, and by suppressing the triggering of the deep convection scheme. It is found that the weak boundary layer turbulence simulated is directly responsible for the weak cumulus activity and the simulated boundary layer stratiform clouds. Increased vertical and temporal resolutions are shown to lead to stronger boundary layer turbulence and reduction of low-cloud biases.

  2. RACORO Continental Boundary Layer Cloud Investigations: 3. Separation of Parameterization Biases in Single-Column Model CAM5 Simulations of Shallow Cumulus

    NASA Technical Reports Server (NTRS)

    Lin, Wuyin; Liu, Yangang; Vogelmann, Andrew M.; Fridlind, Ann; Endo, Satoshi; Song, Hua; Feng, Sha; Toto, Tami; Li, Zhijin; Zhang, Minghua

    2015-01-01

    Climatically important low-level clouds are commonly misrepresented in climate models. The FAst-physics System TEstbed and Research (FASTER) Project has constructed case studies from the Atmospheric Radiation Measurement Climate Research Facility's Southern Great Plain site during the RACORO aircraft campaign to facilitate research on model representation of boundary-layer clouds. This paper focuses on using the single-column Community Atmosphere Model version 5 (SCAM5) simulations of a multi-day continental shallow cumulus case to identify specific parameterization causes of low-cloud biases. Consistent model biases among the simulations driven by a set of alternative forcings suggest that uncertainty in the forcing plays only a relatively minor role. In-depth analysis reveals that the model's shallow cumulus convection scheme tends to significantly under-produce clouds during the times when shallow cumuli exist in the observations, while the deep convective and stratiform cloud schemes significantly over-produce low-level clouds throughout the day. The links between model biases and the underlying assumptions of the shallow cumulus scheme are further diagnosed with the aid of large-eddy simulations and aircraft measurements, and by suppressing the triggering of the deep convection scheme. It is found that the weak boundary layer turbulence simulated is directly responsible for the weak cumulus activity and the simulated boundary layer stratiform clouds. Increased vertical and temporal resolutions are shown to lead to stronger boundary layer turbulence and reduction of low-cloud biases.

  3. Holographic in-line imaging setup for measuring the solid content of fluids

    NASA Astrophysics Data System (ADS)

    Kaikkonen, Ville A.; Mäkynen, Anssi J.

    2013-05-01

    Digital in-line holographic microscopy is a captivating imaging method for industrial applications where large volumes of fluids are to be imaged with microscopic resolution. The lensless holographic in-line imaging setup with a point light source, also known as the Gabor setup, can be built up with just a few, fairly low cost, components. In-line holography is well suited for imaging large volumes with a low concentration of scattering particles as most of the light emitted from the point source should pass through the image volume unscattered. The large depth of field of in-line holographic microscopy makes it possible to image larger volumes with comparable resolutions than what can be achieved with traditional light microscopy methods using low magnification objectives. Despite the many advantages gained over traditional microscopic methods by the use of holographic imaging for large volumes, so far it has only been widely utilized in biological and particle image velocimetry studies. The large depth of field of the holographic microscope permits simultaneous imaging of particles located at different depths without the need for mechanical scanning, and allows the use of large diameter fluidic channels which are not as prone to clogging and enable higher flow rates than smaller fluidic channels. In this paper, we present a digital in-line holographic microscope based measurement principle for measuring the solid particle content of fluids. The method proposed is demonstrated on bio-oil samples whose solid contents are less than 0.01 weight percentage.

  4. Experience of validation and tuning of turbulence models as applied to the problem of boundary layer separation on a finite-width wedge

    NASA Astrophysics Data System (ADS)

    Babulin, A. A.; Bosnyakov, S. M.; Vlasenko, V. V.; Engulatova, M. F.; Matyash, S. V.; Mikhailov, S. V.

    2016-06-01

    Modern differential turbulence models are validated by computing a separation zone generated in the supersonic flow past a compression wedge lying on a plate of finite width. The results of three- and two-dimensional computations based on the ( q-ω), SST, and Spalart-Allmaras turbulence models are compared with experimental data obtained for 8°, 25°, and 45° wedges by A.A. Zheltovodov at the Institute of Theoretical and Applied Mechanics of the Siberian Branch of the Russian Academy of Sciences. An original law-of-the-wall boundary condition and modifications of the SST model intended for improving the quality of the computed separation zone are described.

  5. Analysis of acrylamide in food products by in-line preconcentration capillary zone electrophoresis.

    PubMed

    Bermudo, Elisabet; Núñez, Oscar; Puignou, Luis; Galceran, Maria Teresa

    2006-09-29

    Two in-line preconcentration capillary zone electrophoresis (CZE) methods (field amplified sample injection (FASI) and stacking with sample matrix removal (LVSS)) have been evaluated for the analysis of acrylamide (AA) in foodstuffs. To allow the determination of AA by CZE, it was derivatized using 2-mercaptobenzoic acid. For FASI, the optimum conditions were water at pH > or = 10 adjusted with NH3 as sample solvent, 35 s hydrodynamic injection (0.5 psi) of a water plug, 35 s of electrokinetic injection (-10 kV) of the sample, and 6s hydrodynamic injection (0.5 psi) of another water plug to prevent AA removal by EOF. In stacking with sample matrix removal, the reversal time was found to be around 3.3 min. A 40 mM phosphate buffer (pH 8.5) was used as carrier electrolyte for CZE separation in both cases. For both FASI and LVSS methods, linear calibration curves over the range studied (10-1000 microg L(-1) and 25-1000 microg L(-1), respectively), limit of detection (LOD) on standards (1 microg L(-1) for FASI and 7 microg L(-1) for LVSS), limit of detection on samples (3 ng g(-1) for FASI and 20 ng g(-1) for LVSS) and both run-to-run (up to 14% for concentration and 0.8% for time values) and day-to-day precisions (up to 16% and 5% for concentration and time values, respectively) were established. Due to the lower detection limits obtained with the FASI-CZE this method was applied to the analysis of AA in different foodstuffs such as biscuits, cereals, crisp bread, snacks and coffee, and the results were compared with those obtained by LC-MS/MS. PMID:16843477

  6. Estimation of objects transverse parameters in off-axis and in-line Fresnel digital holography

    NASA Astrophysics Data System (ADS)

    Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.

    2015-05-01

    In this report transverse parameters of objects registered with inline and off-axis Fresnel digital holography schemes were estimated: maximum transverse dimensions of objects, size and quantity of object resolution elements. By determining allowed locations of diffraction orders under reconstruction, new expressions for estimation of objects transverse parameters were obtained. In case of off-axis holography it is desirable that object should not overlap with zero-order and twin images. If object and twin images are located on opposite sides relative to zero-order under reconstruction, this is case of preventing of cyclic shift of twin image (PCS). If twin image is located on both sides relative to zero-order under reconstruction but don't overlap with object image, this is case of assumption of cyclic shift of twin image (ACS). ACS case allows to register digital holograms of larger objects compared to PCS case. However, for example, for automatic image processing, separate display of object and twin images relative to zero-order is often required. It was found that ACS case allows to register holograms with distance between the object and hologram 1.5 times lesser than in PCS case. And maximum transverse dimension of object in ACS case is always greater than in PCS case by the half of hologram size. For verification of obtained estimates, off-axis digital Fresnel holograms with 2048x2048 pixels were optically registered. Contour images located behind static scatter were used as objects. Confirmations on transverse object parameters estimates, satisfying ACS and PCS cases, were derived. These results demonstrate correctness of obtained quantitative estimates.

  7. Digital inline holographic microscopy (DIHM) of weakly-scattering subjects.

    PubMed

    Giuliano, Camila B; Zhang, Rongjing; Wilson, Laurence G

    2014-01-01

    Weakly-scattering objects, such as small colloidal particles and most biological cells, are frequently encountered in microscopy. Indeed, a range of techniques have been developed to better visualize these phase objects; phase contrast and DIC are among the most popular methods for enhancing contrast. However, recording position and shape in the out-of-imaging-plane direction remains challenging. This report introduces a simple experimental method to accurately determine the location and geometry of objects in three dimensions, using digital inline holographic microscopy (DIHM). Broadly speaking, the accessible sample volume is defined by the camera sensor size in the lateral direction, and the illumination coherence in the axial direction. Typical sample volumes range from 200 µm x 200 µm x 200 µm using LED illumination, to 5 mm x 5 mm x 5 mm or larger using laser illumination. This illumination light is configured so that plane waves are incident on the sample. Objects in the sample volume then scatter light, which interferes with the unscattered light to form interference patterns perpendicular to the illumination direction. This image (the hologram) contains the depth information required for three-dimensional reconstruction, and can be captured on a standard imaging device such as a CMOS or CCD camera. The Rayleigh-Sommerfeld back propagation method is employed to numerically refocus microscope images, and a simple imaging heuristic based on the Gouy phase anomaly is used to identify scattering objects within the reconstructed volume. This simple but robust method results in an unambiguous, model-free measurement of the location and shape of objects in microscopic samples. PMID:24561665

  8. Flow past a normal flat plate undergoing inline oscillations

    NASA Astrophysics Data System (ADS)

    Khaledi, Hatef A.; Andersson, Helge I.; Barri, Mustafa; Pettersen, Bjørnar

    2012-09-01

    The flow past an inline oscillating normal flat plate has been considered with the view to explore the variety of wake phenomena which arise even at the low Reynolds number (Re) equal to 100 based on the free stream velocity and the width of the plate. The three-dimensional Navier-Stokes equations were integrated in time over a wide range of excitation frequencies and amplitudes. A wake flow regime map was produced on the basis of the 24 computer simulations. For a certain excitation amplitude, the wake vortex shedding is first antisymmetric at low excitation frequencies fe. When fe is increased the wake first becomes chaotic and thereafter turns into a symmetric shedding mode, for instance the S-II mode with a binary vortex pair on each side of the wake. If fe is increased even further, more complex symmetric wake patterns may occur before the wake ultimately turns into chaos. Symmetric wakes are thus only observed in a band of intermediate excitation frequencies and then with the dominating flow frequency locked-on to fe. In one particular case, the S-II mode in the very near wake turned into what might be considered as a new S-IV mode which comprised four different vortex pairs per shedding cycle. In spite of the low Re considered, several cases exhibited distinct three-dimensionalities whereas some other cases remained strictly 2D. In some of the cases, at least, the transition from 2D to 3D wake flow was ascribed to a "mode competition." Finally, for one of the two-dimensional cases the Reynolds number was first increased to 300 and then to 500 and a complex three-dimensional wake flow was observed. However, even at Re = 100, two-dimensional computer simulations are unable to reproduce the three-dimensional wake flow characteristics reported from the present study.

  9. Digital Inline Holographic Microscopy (DIHM) of Weakly-scattering Subjects

    PubMed Central

    Giuliano, Camila B.; Zhang, Rongjing; Wilson, Laurence G.

    2014-01-01

    Weakly-scattering objects, such as small colloidal particles and most biological cells, are frequently encountered in microscopy. Indeed, a range of techniques have been developed to better visualize these phase objects; phase contrast and DIC are among the most popular methods for enhancing contrast. However, recording position and shape in the out-of-imaging-plane direction remains challenging. This report introduces a simple experimental method to accurately determine the location and geometry of objects in three dimensions, using digital inline holographic microscopy (DIHM). Broadly speaking, the accessible sample volume is defined by the camera sensor size in the lateral direction, and the illumination coherence in the axial direction. Typical sample volumes range from 200 µm x 200 µm x 200 µm using LED illumination, to 5 mm x 5 mm x 5 mm or larger using laser illumination. This illumination light is configured so that plane waves are incident on the sample. Objects in the sample volume then scatter light, which interferes with the unscattered light to form interference patterns perpendicular to the illumination direction. This image (the hologram) contains the depth information required for three-dimensional reconstruction, and can be captured on a standard imaging device such as a CMOS or CCD camera. The Rayleigh-Sommerfeld back propagation method is employed to numerically refocus microscope images, and a simple imaging heuristic based on the Gouy phase anomaly is used to identify scattering objects within the reconstructed volume. This simple but robust method results in an unambiguous, model-free measurement of the location and shape of objects in microscopic samples. PMID:24561665

  10. Deriving Particle Distributions from In-Line Fraunhofer Holographic Data

    SciTech Connect

    C.A. Ciarcia; D.E. Johnson; D.S. Sorenson; R.H. Frederickson, A.D. Delanoy; R.M. Malone; T.W. Tunnel

    1997-08-01

    Holographic data are acquired during hydrodynamic experiments at the Pegasus Pulsed Power Facility at the Los Alamos National Laboratory. These experiments produce a fine spray of fast-moving particles. Snapshots of the spray are captured using in-line Fraunhofer holographic techniques. Roughly one cubic centimeter is recorded by the hologram. Minimum detectable particle size in the data extends down to 2 microns. In a holography reconstruction system, a laser illuminates the hologram as it rests in a three-axis actuator, recreating the snapshot of the experiment. A computer guides the actuators through an orderly sequence programmed by the user. At selected intervals, slices of this volume are captured and digitized with a CCD camera. Intermittent on-line processing of the image data and computer control of the camera functions optimizes statistics of the acquired image data for off-line processing. Tens of thousands of individual data frames (30 to 40 gigabytes of data) are required to recreate a digital representation of the snapshot. Throughput of the reduction system is 550 megabytes per hour (MB/hr). Objects and associated features from the data are subsequently extracted during off-line processing. Discrimination and correlation tests reject noise, eliminate multiple counting of particles, and build an error model to estimate performance. Objects surviving these tests are classified as particles. The particle distributions are derived from the data base formed by these particles, their locations and features. Throughput of the off-line processing exceeds 500 MB/hr. This paper describes the reduction system, outlines the off-line processing procedure, summarizes the discrimination and correlation tests, and reports numerical results for a sample data set.

  11. GaInN light-emitting diodes using separate epitaxial growth for the p-type region to attain polarization-inverted electron-blocking layer, reduced electron leakage, and improved hole injection

    SciTech Connect

    Meyaard, David S. Lin, Guan-Bo; Ma, Ming; Fred Schubert, E.; Cho, Jaehee; Han, Sang-Heon; Kim, Min-Ho; Shim, HyunWook; Sun Kim, Young

    2013-11-11

    A GaInN light-emitting diode (LED) structure is analyzed that employs a separate epitaxial growth for the p-type region, i.e., the AlGaN electron-blocking layer (EBL) and p-type GaN cladding layer, followed by wafer or chip bonding. Such LED structure has a polarization-inverted EBL and allows for uncompromised epitaxial-growth optimization of the p-type region, i.e., without the need to consider degradation of the quantum-well active region during p-type region growth. Simulations show that such an LED structure reduces electron leakage, reduces the efficiency droop, improves hole injection, and has the potential to extend high efficiencies into the green spectral region.

  12. Industrial application of ultrasound based in-line rheometry: Visualization of steady shear pipe flow of chocolate suspension in pre-crystallization process

    NASA Astrophysics Data System (ADS)

    Ouriev, Boris; Windhab, Erich; Braun, Peter; Zeng, Yuantong; Birkhofer, Beat

    2003-12-01

    In the present work an in-line ultrasonic method for investigation of the rheological flow behavior of concentrated suspensions was created. It is based on a nondestructive rheological measuring technique for pilot plant and industrial scale applications. Elsewhere the author discusses a tremendous need for in-line rheological characterization of highly concentrated suspensions exposed to pressure driven shear flow conditions. Most existing on-line methods are based on destructive macro actuators, which are not suitable for materials with sensitive to applied deformation structure. Since the process of our basic interest influences the structure of suspension it would be difficult to separate the effects of rheometric measurement and weakly pronounced structural changes arising from a fine adjustment of the process parameters. The magnitude of these effects is usually associated with the complex flow dynamics of structured liquids and is sensitive to density or temperature fluctuations around the moving rheometric actuator. Interpretation of the results of such measurements can be hindered by process parameter influences on liquid product structure. Therefore, the author introduces an in-line noninvasive rheometric method, which is implemented in a pre-crystallization process of chocolate suspension. Use of ultrasound velocity profile pressure difference (UVP-PD) technique enabled process monitoring of the chocolate pre-crystallization process. Influence of seeded crystals on Rheology of chocolate suspension was recorded and monitored on line. It was shown that even slight velocity pulsations in chocolate mainstream can strongly influence rheological properties besides influencing flow velocity profiles. Based on calculations of power law fit in raw velocity profiles and calculation of wall shear stress from pressure difference measurement, a viscosity function was calculated and monitored on line. On-line results were found to be in a good agreement with off

  13. 47 CFR 25.261 - Procedures for avoidance of in-line interference events for Non Geostationary Satellite Orbit...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Procedures for avoidance of in-line interference events for Non Geostationary Satellite Orbit (NGSO) Satellite Network Operations in the Fixed... avoidance of in-line interference events for Non Geostationary Satellite Orbit (NGSO) Satellite...

  14. 47 CFR 25.261 - Procedures for avoidance of in-line interference events for Non Geostationary Satellite Orbit...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Procedures for avoidance of in-line interference events for Non Geostationary Satellite Orbit (NGSO) Satellite Network Operations in the Fixed... avoidance of in-line interference events for Non Geostationary Satellite Orbit (NGSO) Satellite...

  15. 47 CFR 25.261 - Procedures for avoidance of in-line interference events for Non Geostationary Satellite Orbit...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Procedures for avoidance of in-line interference events for Non Geostationary Satellite Orbit (NGSO) Satellite Network Operations in the Fixed... avoidance of in-line interference events for Non Geostationary Satellite Orbit (NGSO) Satellite...

  16. 40 CFR 63.1344 - Operating limits for kilns and in-line kiln/raw mills.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Operating limits for kilns and in-line kiln/raw mills. 63.1344 Section 63.1344 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Industry Emission Standards and Operating Limits § 63.1344 Operating limits for kilns and in-line...

  17. In-line mixing states monitoring of suspensions using ultrasonic reflection technique.

    PubMed

    Zhan, Xiaobin; Yang, Yili; Liang, Jian; Zou, Dajun; Zhang, Jiaqi; Feng, Luyi; Shi, Tielin; Li, Xiwen

    2016-02-01

    Based on the measurement of echo signal changes caused by different concentration distributions in the mixing process, a simple ultrasonic reflection technique is proposed for in-line monitoring of the mixing states of suspensions in an agitated tank in this study. The relation between the echo signals and the concentration of suspensions is studied, and the mixing process of suspensions is tracked by in-line measurement of ultrasonic echo signals using two ultrasonic sensors. Through the analysis of echo signals over time, the mixing states of suspensions are obtained, and the homogeneity of suspensions is quantified. With the proposed technique, the effects of impeller diameter and agitation speed on the mixing process are studied, and the optimal agitation speed and the minimum mixing time to achieve the maximum homogeneity are acquired under different operating conditions and design parameters. The proposed technique is stable and feasible and shows great potential for in-line monitoring of mixing states of suspensions. PMID:26548526

  18. Inline detection of Chrome degradation on binary 193nm photomasks

    NASA Astrophysics Data System (ADS)

    Dufaye, Félix; Sippel, Astrid; Wylie, Mark; García-Berríos, Edgardo; Crawford, Charles; Hess, Carl; Sartelli, Luca; Pogliani, Carlo; Miyashita, Hiroyuki; Gough, Stuart; Sundermann, Frank; Brochard, Christophe

    2013-09-01

    193nm binary photomasks are still used in the semiconductor industry for the lithography of some critical layers for the nodes 90nm and 65nm, with high volumes and over long periods. However, these 193nm binary photomasks can be impacted by a phenomenon of chrome oxidation leading to critical dimensions uniformity (CDU) degradation with a pronounced radial signature. If not detected early enough, this CDU degradation may cause defectivity issues and lower yield on wafers. Fortunately, a standard cleaning and repellicle service at the mask shop has been demonstrated as efficient to remove the grown materials and get the photomask CD back on target.Some detection methods have been already described in literature, such as wafer CD intrafield monitoring (ACLV), giving reliable results but also consuming additional SEM time with less precision than direct photomask measurement. In this paper, we propose another approach, by monitoring the CDU directly on the photomask, concurrently with defect inspection for regular requalification to production for wafer fabs. For this study, we focused on a Metal layer in a 90nm technology node. Wafers have been exposed with production conditions and then measured by SEM-CD. Afterwards, this photomask has been measured with a SEM-CD in mask shop and also inspected on a KLA-Tencor X5.2 inspection system, with pixels 125 and 90nm, to evaluate the Intensity based Critical Dimension Uniformity (iCDU) option. iCDU was firstly developed to provide feed-forward CDU maps for scanner intrafield corrections, from arrayed dense structures on memory photomasks. Due to layout complexity and differing feature types, CDU monitoring on logic photomasks used to pose unique challenges.The selection of suitable feature types for CDU monitoring on logic photomasks is no longer an issue, since the transmitted intensity map gives all the needed information, as shown in this paper. In this study, the photomask was heavily degraded after more than 18,000 300

  19. Comparison of an Inductance In-Line Oil Debris Sensor and Magnetic Plug Oil Debris Sensor

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Tuck, Roger; Showalter, Stephen

    2012-01-01

    The objective of this research was to compare the performance of an inductance in-line oil debris sensor and magnetic plug oil debris sensor when detecting transmission component health in the same system under the same operating conditions. Both sensors were installed in series in the NASA Glenn Spiral Bevel Gear Fatigue Rig during tests performed on 5 gear sets (pinion/gear) when different levels of damage occurred on the gear teeth. Results of this analysis found both the inductance in-line oil debris sensor and magnetic plug oil debris sensor have benefits and limitations when detecting gearbox component damage.

  20. Advanced in-line optical metrology of sub-10nm structures for gate all around devices (GAA)

    NASA Astrophysics Data System (ADS)

    Muthinti, Raja; Loubet, Nicolas; Chao, Robin; Ott, John; Guillorn, Michael; Felix, Nelson; Gaudiello, John; Lund, Parker; Cepler, Aron; Sendelbach, Matthew; Cohen, Oded; Wolfling, Shay; Bozdog, Cornel; Klare, Mark

    2016-03-01

    Gate-all-around (GAA) nanowire (NW) devices have long been acknowledged as the ultimate device from an electrostatic scaling point of view. The GAA architecture offers improved short channel effect (SCE) immunity compared to single and double gate planar, FinFET, and trigate structures. One attractive proposal for making GAA devices involves the use of a multilayer fin-like structure consisting of layers of Si and SiGe. However, such structures pose various metrology challenges, both geometrical and material. Optical Scatterometry, also called optical critical dimension (OCD) is a fast, accurate and non-destructive in-line metrology technique well suited for GAA integration challenges. In this work, OCD is used as an enabler for the process development of nanowire devices, extending its abilities to learn new material and process aspects specific to this novel device integration. The specific metrology challenges from multiple key steps in the process flow are detailed, along with the corresponding OCD solutions and results. In addition, Low Energy X-Ray Fluorescence (LE-XRF) is applied to process steps before and after the removal of the SiGe layers in order to quantify the amount of Ge present at each step. These results are correlated to OCD measurements of the Ge content, demonstrating that both OCD and LE-XRF are sensitive to Ge content for these applications.

  1. This-layer chromatography/electrospray ionization triple-quadrupole linear ion trap mass spectrometry system: analysis of rhodamine dyes separated on reversed-phase C8 plates

    SciTech Connect

    Ford, Michael J; Kertesz, Vilmos; Van Berkel, Gary J

    2005-01-01

    The direct analysis of separated rhodamine dyes on reversed-phase C{sub 8} thin-layer chromatography plates using a surface sampling/electrospray emitter probe coupled with a triple-quadrupole linear ion trap mass spectrometer is presented. This report represents continuing work to advance the performance metrics and utility of this basic surface sampling electrospray mass spectrometry system for the analysis of thin-layer chromatography plates. Experimental results examining the role of sampling probe spray end configuration on liquid aspiration rate and gas-phase ion signal generated are discussed. The detection figures-of-merit afforded by full-scan, automated product ion and selected reaction monitoring modes of operation were examined. The effect of different eluting solvents on mass spectrum signal levels with the reversed-phase C{sub 8} plate was investigated. The combined effect of eluting solvent flow-rate and development lane surface scan rate on preservation of chromatographic resolution was also studied. Analysis of chromatographically separated red pen ink extracts from eight different pens using selected reaction monitoring demonstrated the potential of this surface sampling electrospray mass spectrometry system for targeted compound analysis with real samples.

  2. Resolution and isolation of enantiomers of (±)-isoxsuprine using thin silica gel layers impregnated with L-glutamic acid, comparison of separation of its diastereomers prepared with chiral derivatizing reagents having L-amino acids as chiral auxiliaries.

    PubMed

    Bhushan, Ravi; Nagar, Hariom

    2015-03-01

    Thin silica gel layers impregnated with optically pure l-glutamic acid were used for direct resolution of enantiomers of (±)-isoxsuprine in their native form. Three chiral derivatizing reagents, based on DFDNB moiety, were synthesized having l-alanine, l-valine and S-benzyl-l-cysteine as chiral auxiliaries. These were used to prepare diastereomers under microwave irradiation and conventional heating. The diastereomers were separated by reversed-phase high-performance liquid chromatography on a C18 column with detection at 340 nm using gradient elution with mobile phase containing aqueous trifluoroacetic acid and acetonitrile in different compositions and by thin-layer chromatography (TLC) on reversed phase (RP) C18 plates. Diastereomers prepared with enantiomerically pure (+)-isoxsuprine were used as standards for the determination of the elution order of diastereomers of (±)-isoxsuprine. The elution order in the experimental study of RP-TLC and RP-HPLC supported the developed optimized structures of diastereomers based on density functional theory. The limit of detection was 0.1-0.09 µg/mL in TLC while it was in the range of 22-23 pg/mL in HPLC and 11-13 ng/mL in RP-TLC for each enantiomer. The conditions of derivatization and chromatographic separation were optimized. The method was validated for accuracy, precision, limit of detection and limit of quantification. PMID:25044026

  3. Low-parachor solvents extraction and thermostated micro-thin-layer chromatography separation for fast screening and classification of spirulina from pharmaceutical formulations and food samples.

    PubMed

    Zarzycki, Paweł K; Zarzycka, Magdalena B; Clifton, Vicki L; Adamski, Jerzy; Głód, Bronisław K

    2011-08-19

    The goal of this paper is to demonstrate the separation and detection capability of eco-friendly micro-TLC technique for the classification of spirulina and selected herbs from pharmaceutical and food products. Target compounds were extracted using relatively low-parachor liquids. A number of the spirulina samples which originated from pharmaceutical formulations and food products, were isolated using a simple one step extraction with small volume of methanol, acetone or tetrahydrofuran. Herb samples rich in chlorophyll dyes were analyzed as reference materials. Quantitative data derived from micro-plates under visible light conditions and after iodine staining were explored using chemometrics tools including cluster analysis and principal components analysis. Using this method we could easily distinguish genuine spirulina and non-spirulina samples as well as fresh from expired commercial products and furthermore, we could identify some biodegradation peaks appearing on micro-TLC profiles. This methodology can be applied as a fast screening or fingerprinting tool for the classification of genuine spirulina and herb samples and in particular may be used commercially for the rapid quality control screening of products. Furthermore, this approach allows low-cost fractionation of target substances including cyanobacteria pigments in raw biological or environmental samples for preliminary chemotaxonomic investigations. Due to the low consumption of the mobile phase (usually less than 1 mL per run), this method can be considered as environmentally friendly analytical tool, which may be an alternative for fingerprinting protocols based on HPLC machines and simple separation systems involving planar micro-fluidic or micro-chip devices. PMID:21741048

  4. IEMDC IN-LINE ELECTRIC MOTOR DRIVEN COMPRESSOR

    SciTech Connect

    Michael J. Crowley; Prem N. Bansal

    2004-10-01

    This report contains the final project summary and deliverables required by the award for the development of an In-line Electric Motor Driven Compressor (IEMDC). Extensive work was undertaken during the course of the project to develop the motor and the compressor section of the IEMDC unit. Multiple design iterations were performed to design an electric motor for operation in a natural gas environment and to successfully integrate the motor with a compressor. During the project execution, many challenges were successfully overcome in order to achieve the project goals and to maintain the system design integrity. Some of the challenges included limiting the magnitude of the compressor aerodynamic loading for appropriate sizing of the magnetic bearings, achieving a compact motor rotor size to meet the rotor dynamic requirements of API standards, devising a motor cooling scheme using high pressure natural gas, minimizing the impact of cooling on system efficiency, and balancing the system thrust loads for the magnetic thrust bearing. Design methods that were used on the project included validated state-of-the-art techniques such as finite element analysis and computational fluid dynamics along with the combined expertise of both Curtiss-Wright Electro-Mechanical Corporation and Dresser-Rand Company. One of the most significant areas of work undertaken on the project was the development of the unit configuration for the system. Determining the configuration of the unit was a significant step in achieving integration of the electric motor into a totally enclosed compression system. Product review of the IEMDC unit configuration was performed during the course of the development process; this led to an alternate design configuration. The alternate configuration is a modular design with the electric motor and compressor section each being primarily contained in its own pressure containing case. This new concept resolved the previous conflict between the aerodynamic flow

  5. Vortex-induced vibration of four cylinders in an in-line square configuration

    NASA Astrophysics Data System (ADS)

    Zhao, Ming; Kaja, Kalyani; Xiang, Yang; Cheng, Liang

    2016-02-01

    This paper presents a numerical study of vortex-induced vibration of four rigidly connected and four separately mounted circular cylinders in an inline square configuration at a Reynolds number of 150, a low mass ratio of 2.5, and a range of spacing ratio L from 1.5 to 4, where the spacing ratio is defined as the centre-to-centre distance of two adjacent cylinders normalized by the cylinder diameter. For the rigidly connected cylinder array, the maximum and minimum response amplitudes occur at L = 1.5 and L = 2.0, respectively, for the range of spacing ratio covered in this study and the maximum response amplitude at L = 1.5 is accompanied by a wide lock-in range. The large response amplitude at a small spacing ratio L = 1.5 is because the cylinder array responds to the flow as a single cylinder with an overall size that is much larger than the diameter of the single cylinder while the small response amplitude observed at L = 2.0 is attributed to the strong interaction of the vortices through the gap between the top and bottom rows of the cylinder and also in the wake of the cylinder array. For spacing ratio L ≥ 2.5, the lock-in regime of four rigidly connected cylinders is similar to that of a single cylinder and the response amplitudes in the lock-in regime are slightly higher than that of a single cylinder. The energy transfer analysis between fluid flow and individual cylinders in the array shows that the hydrodynamic forces on individual cylinders either excite or damp the vibration, depending on the reduced velocity. An interesting flow feature observed at L = 2, 2.5, and 3 is the biased vortex street in the wake of four rigidly connected cylinders. The biased vortex street leads to a shift of the mean position of the cylinder array with the largest mean position shift being observed at L = 3. Four response modes are identified for four separately mounted cylinders. These are the in-phase mode, the anti-phase mode, the correlated out-of-phase mode, and the

  6. An evaluation of phase separated, self-assembled LaMnO3-MgO nanocomposite films directly on IBAD-MgO as buffer layers for flux pinning enhancements in YBa2YCu3O7-& coated conductors

    SciTech Connect

    Polat, Ozgur; Aytug, Tolga; Paranthaman, Mariappan Parans; Leonard, Keith J; Lupini, Andrew R; Pennycook, Stephen J; Meyer III, Harry M; Kim, Kyunghoon; Qiu, Xiaofeng; Cook, Sylvester W; Thompson, James R; Christen, David K; Goyal, Amit; Selvamanickam, V.; Xiong, X.

    2010-01-01

    Technological applications of high temperature superconductors (HTS) require high critical current density, Jc, under operation at high magnetic field strengths. This requires effective flux pinning by introducing artificial defects through creative processing. In this work, we evaluated the feasibility of mixed-phase LaMnO3:MgO (LMO:MgO) films as a potential cap buffer layer for the epitaxial growth and enhanced performance of YBa2Cu3O7-d (YBCO) films. Such composite films were sputter deposited directly on IBAD-MgO templates (with no additional homo-epitaxial MgO layer) and revealed the formation of two phase-separated, but at the same time vertically aligned, self-assembled composite nanostructures that extend throughout the entire thickness of the film. The YBCO coatings deposited on these nanostructured cap layers showed correlated c-axis pinning and improved in-field Jc performance compared to those of YBCO films fabricated on standard LMO buffers. Microstructural characterization revealed additional extended disorder in the YBCO matrix. The present results demonstrate the feasibility of novel and potentially practical approaches in the pursuit of more efficient, economical, and high performance superconducting devices.

  7. Ultracapacitor separator

    DOEpatents

    Wei, Chang; Jerabek, Elihu Calvin; LeBlanc, Jr., Oliver Harris

    2001-03-06

    An ultracapacitor includes two solid, nonporous current collectors, two porous electrodes separating the collectors, a porous separator between the electrodes and an electrolyte occupying the pores in the electrodes and separator. The electrolyte is a polar aprotic organic solvent and a salt. The porous separator comprises a wet laid cellulosic material.

  8. Experimental imaging research on continuous-wave terahertz in-line digital holography

    NASA Astrophysics Data System (ADS)

    Huang, Haochong; Wang, Dayong; Rong, Lu; Wang, Yunxin

    2014-09-01

    The terahertz (THz) imaging is an advanced technique on the basis of the unique characteristics of terahertz radiation. Due to its noncontact, non-invasive and high-resolution capabilities, it has already shown great application prospects in biomedical observation, sample measurement, and quality control. The continuous-wave terahertz in-line digital holography is a combination of terahertz technology and in-line digital holography of which the source is a continuous-wave terahertz laser. Over the past decade, many researchers used different terahertz sources and detectors to undertake experiments. In this paper, the pre-process of the hologram is accomplished after the holograms' recording process because of the negative pixels in the pyroelectric detector and the air vibration caused by the chopper inside the camera. To improve the quality of images, the phase retrieval algorithm is applied to eliminate the twin images. In the experiment, the pin which terahertz wave can't penetrate and the TPX slice carved letters "THz" are chosen for the samples. The amplitude and phase images of samples are obtained and the twin image and noise in the reconstructed images are suppressed. The results validate the feasibility of the terahertz in-line digital holographic imaging technique. This work also shows the terahertz in-line digital holography technique's prospects in materials science and biological samples' detection.

  9. Scheduling of multiple in-line steppers for semiconductor wafer fabs

    NASA Astrophysics Data System (ADS)

    Chiou, Chie-Wun; Wu, Muh-Cherng

    2014-03-01

    A few prior studies noticed that an in-line stepper (a bottleneck machine in a semiconductor fab) may have a capacity loss while operated in a low-yield scenario. To alleviate such a capacity loss, some meta-heuristic algorithms for scheduling a single in-line stepper were proposed. Yet, in practice, there are multiple in-line steppers to be scheduled in a fab. This article aims to enhance prior algorithms so as to deal with the scheduling for multiple in-line steppers. Compared to prior studies, this research has to additionally consider how to appropriately allocate jobs to various machines. We enhance prior algorithms by developing a chromosome-decoding scheme which can yield a job-allocation decision for any given chromosome (or job sequence). Seven enhanced versions of meta-heuristic algorithms (genetic algorithm, Tabu, GA-Tabu, simulated annealing, M-MMAX, PACO and particle swarm optimisation) were then proposed and tested. Numerical experiments indicate that the GA-Tabu method outperforms the others. In addition, the lower the process yield, the better is the performance of the GA-Tabu algorithm.

  10. MEASURING GRAIN PROTEIN CONCENTRATION WITH IN-LINE NEAR INFRARED REFLECTANCE SPECTROSCOPY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the advent of near infrared spectroscopic sensors, growers have the opportunity to measure the protein concentration of grain within farm fields during machine harvest. A feasibility study was conducted to determine whether the protein content of grain could be measured directly with an in-lin...

  11. 30 CFR 57.22210 - In-line filters (I-C mines).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false In-line filters (I-C mines). 57.22210 Section 57.22210 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES...

  12. An Automated Statistical Process Control Study of Inline Mixing Using Spectrophotometric Detection

    ERIC Educational Resources Information Center

    Dickey, Michael D.; Stewart, Michael D.; Willson, C. Grant

    2006-01-01

    An experiment is described, which is designed for a junior-level chemical engineering "fundamentals of measurements and data analysis" course, where students are introduced to the concept of statistical process control (SPC) through a simple inline mixing experiment. The students learn how to create and analyze control charts in an effort to…

  13. Separation membrane development

    SciTech Connect

    Lee, M.W.

    1998-08-01

    A ceramic membrane has been developed to separate hydrogen from other gases. The method used is a sol-gel process. A thin layer of dense ceramic material is coated on a coarse ceramic filter substrate. The pore size distribution in the thin layer is controlled by a densification of the coating materials by heat treatment. The membrane has been tested by permeation measurement of the hydrogen and other gases. Selectivity of the membrane has been achieved to separate hydrogen from carbon monoxide. The permeation rate of hydrogen through the ceramic membrane was about 20 times larger than Pd-Ag membrane.

  14. Measurement of the direct CP -violating parameter ACP in the decay D+K-π+π+

    SciTech Connect

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Borysova, M.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M. -C.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duperrin, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, V. N.; Fauré, A.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Gogota, O.; Golovanov, G.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J. -F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Holzbauer, J. L.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kaur, M.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kurča, T.; Kuzmin, V. A.; Lammers, S.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M. -A.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Ratoff, P. N.; Razumov, I.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Savitskyi, M.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Titov, M.; Tokmenin, V. V.; Tsai, Y. -T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verkheev, A. Y.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vilanova, D.; Vokac, P.; Wahl, H. D.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Williams, M. R. J.; Wilson, G. W.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yang, S.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.

    2014-12-01

    We measure the direct <inline-formula>inline">CPinline-formula>-violating parameter <inline-formula>inline">ACPinline-formula> for the decay of the charged charm meson, <inline-formula>inline">D+K-π+π+inline-formula> (and charge conjugate), using the full <inline-formula>inline">10.4 fb-1inline-formula> sample of <inline-formula>inline">pp¯inline-formula> collisions at <inline-formula>inline">s=1.96 TeVinline-formula> collected by the D0 detector at the Fermilab Tevatron collider. We extract the raw reconstructed charge asymmetry by fitting the invariant mass distributions for the sum and difference of charge-specific samples. This quantity is then corrected for detector-related asymmetries using data-driven methods and for possible physics asymmetries (from <inline-formula>inline">BDinline

  15. A novel electron gun for inline MRI-linac configurations

    SciTech Connect

    Constantin, Dragoş E. Fahrig, Rebecca; Holloway, Lois; Keall, Paul J.

    2014-02-15

    Purpose: This work introduces a new electron gun geometry capable of robust functioning in the presence of a high strength external magnetic field for axisymmetric magnetic resonance imaging (MRI)-linac configurations. This allows an inline MRI-linac to operate without the need to isolate the linear accelerator (linac) using a magnetic shield. This MRI-linac integration approach not only leaves the magnet homogeneity unchanged but also provides the linac flexibility to move along the magnet axis of symmetry if the source to target distance needs to be adjusted. Methods: Simple electron gun geometry modifications of a Varian 600C electron gun are considered and solved in the presence of an external magnetic field in order to determine a set of design principles for the new geometry. Based on these results, a new gun geometry is proposed and optimized in the fringe field of a 0.5 T open bore MRI magnet (GE Signa SP). A computer model for the 6 MeV Varian 600C linac is used to determine the capture efficiency of the new electron gun-linac system in the presence of the fringe field of the same MRI scanner. The behavior of the new electron gun plus the linac system is also studied in the fringe fields of two other magnets, a 1.0 T prototype open bore magnet and a 1.5 T GE Conquest scanner. Results: Simple geometrical modifications of the original electron gun geometry do not provide feasible solutions. However, these tests show that a smaller transverse cathode diameter with a flat surface and a slightly larger anode diameter could alleviate the current loss due to beam interactions with the anode in the presence of magnetic fields. Based on these findings, an initial geometry resembling a parallel plate capacitor with a hole in the anode is proposed. The optimization procedure finds a cathode-anode distance of 5 mm, a focusing electrode angle of 5°, and an anode drift tube length of 17.1 mm. Also, the linac can be displaced with ±15 cm along the axis of the 0.5 T

  16. A novel electron gun for inline MRI-linac configurations

    PubMed Central

    Constantin, Dragoş E.; Holloway, Lois; Keall, Paul J.; Fahrig, Rebecca

    2014-01-01

    Purpose: This work introduces a new electron gun geometry capable of robust functioning in the presence of a high strength external magnetic field for axisymmetric magnetic resonance imaging (MRI)-linac configurations. This allows an inline MRI-linac to operate without the need to isolate the linear accelerator (linac) using a magnetic shield. This MRI-linac integration approach not only leaves the magnet homogeneity unchanged but also provides the linac flexibility to move along the magnet axis of symmetry if the source to target distance needs to be adjusted. Methods: Simple electron gun geometry modifications of a Varian 600C electron gun are considered and solved in the presence of an external magnetic field in order to determine a set of design principles for the new geometry. Based on these results, a new gun geometry is proposed and optimized in the fringe field of a 0.5 T open bore MRI magnet (GE Signa SP). A computer model for the 6 MeV Varian 600C linac is used to determine the capture efficiency of the new electron gun-linac system in the presence of the fringe field of the same MRI scanner. The behavior of the new electron gun plus the linac system is also studied in the fringe fields of two other magnets, a 1.0 T prototype open bore magnet and a 1.5 T GE Conquest scanner. Results: Simple geometrical modifications of the original electron gun geometry do not provide feasible solutions. However, these tests show that a smaller transverse cathode diameter with a flat surface and a slightly larger anode diameter could alleviate the current loss due to beam interactions with the anode in the presence of magnetic fields. Based on these findings, an initial geometry resembling a parallel plate capacitor with a hole in the anode is proposed. The optimization procedure finds a cathode-anode distance of 5 mm, a focusing electrode angle of 5°, and an anode drift tube length of 17.1 mm. Also, the linac can be displaced with ±15 cm along the axis of the 0.5 T

  17. Inline Transmitter/Receiver System Using Pb(Zn1/3Nb2/3)O3-PbTiO3 Single Crystal and Poly(vinylidene fluoride) for Harmonic Pulse Compression Imaging

    NASA Astrophysics Data System (ADS)

    Tanabe, Masayuki; Okubo, Kan; Tagawa, Norio; Moriya, Tadashi

    2008-05-01

    An inline transmitter/receiver system for intravascular ultrasound for realizing fine imaging with high resolution and high signal-to-noise ratio (SNR) is newly proposed. This system can be used for tissue harmonic imaging using pulse compression. In this system, a Pb(Zn1/3Nb2/3)O3-PbTiO3 (PZN-PT) layer is applied to the transmitter with consideration of efficient transmission, and a poly(vinylidene fluoride) (PVDF) film is used as the receiver because of its wide bandwidth, which is suitable for receiving harmonic components in echo signals. An inline structure, in which the beam axis of a transmitter coincides with that of a receiver, is required to regard the high directivity of the harmonic components as important. In this system, since coded pulses are transmitted from a PZN-PT layer through a PVDF film, which is placed on the transmission side of the PZN-PT layer, a transmitted pulse is mixed with the received echo signal. To avoid such mixing, another PVDF film is placed on the reverse side of the PZN-PT layer to cancel the transmitted pulse. Through experiments, we investigate the effectiveness of the proposed invention, and confirm the feasibility of the proposed system.

  18. Ejecta Particle-Size Measurements in Vacuum and Helium Gas using Ultraviolet In-Line Fraunhofer Holography

    SciTech Connect

    Sorenson, Danny S.; Pazuchanics, Peter; Johnson, Randall P.; Malone, R. M.; Kaufman, M. I.; Tibbitts, A.; Tunnell, T.; Marks, D.; Capelle, G. A.; Grover, M.; Marshall, B.; Stevens, G. D.; Turley, W. D.; LaLone, B.

    2014-06-25

    An Ultraviolet (UV) in-line Fraunhofer holography diagnostic has been developed for making high-resolution spatial measurements of ejecta particles traveling at many mm/μsec. This report will discuss the development of the diagnostic including the high-powered laser system and high-resolution optical relay system. In addition, the system required to reconstruct the images from the hologram and the corresponding analysis of those images to extract particles will also be described. Finally, results from six high-explosive (HE), shock-driven Sn ejecta experiments will be presented. Particle size distributions will be shown that cover most of the ejecta velocities for experiments conducted in a vacuum, and helium gas environments. In addition, a modification has been made to the laser system that produces two laser pulses separated by 6.8 ns. This double-pulsed capability allows a superposition of two holograms to be acquired at two different times, thus allowing ejecta velocities to be measured directly. Results from this double pulsed experiment will be described.

  19. Finding an improved amorphous-silicon x-ray flat-panel detector configuration for the in-line geometry.

    PubMed

    Fast, M F; Teymurazyan, A; Pang, G; Oelfke, U; Rowlands, J A

    2013-04-01

    We have previously investigated the use of a conventional amorphous-silicon flat-panel detector (FPD) for intrafractional image guidance in the in-line geometry. In this configuration, the FPD is mounted between the patient and the treatment head, with the front of the FPD facing towards the patient. By geometrically separating signals from the diagnostic (kV) and treatment (MV) beams, it is possible to monitor the patient and treatment beam at the same time. In this study, we propose an FPD design based on existing technology with a 70% reduced up-stream areal density that is more suited to this new application. We have investigated our FPD model by means of a validated Monte Carlo simulation. Experimentally, simple rectangular fields were used to irradiate through the detector and observe the impact of removing detector components such as the support structure or the phosphor screen on the measured signal. The proposed FPD performs better than the conventional FPD: (i) attenuation of the MV beam is decreased by 60%; (ii) the MV signal is reduced by 20% for the primary MV field region which can avoid saturation of the FPD; and (iii) long range scatter from the MV into the kV region of the detector is greatly reduced. PMID:23478634

  20. Ejecta Particle-Size Measurements in Vacuum and Helium Gas using Ultraviolet In-Line Fraunhofer Holography

    SciTech Connect

    Sorenson, D. S.; Pazuchanics, P.; Johnson, R.; Malone, R. M.; Kaufman, M. I.; Tibbitts, A.; Tunnell, T.; Marks, D.; Capelle, G. A.; Grover, M.; Marshall, B.; Stevens, G. D.; Turley, W. D.; LaLone, B.

    2014-06-30

    An ultraviolet (UV) in-line Fraunhofer holography diagnostic has been developed for making high-resolution spatial measurements of ejecta particles traveling at many mm/μsec. This report will discuss the development of the diagnostic, including the high-powered laser system and high-resolution optical relay system. In addition, we will also describe the system required to reconstruct the images from the hologram and the corresponding analysis of those images to extract particles. Finally, we will present results from six high-explosive (HE), shock-driven Sn-ejecta experiments. Particle-size distributions will be shown that cover most of the ejecta velocities for experiments conducted in a vacuum, and helium gas environments. In addition, a modification has been made to the laser system that produces two laser pulses separated by 6.8 ns. This double-pulsed capability allows a superposition of two holograms to be acquired at two different times, thus allowing ejecta velocities to be measured directly. Results from this double-pulsed experiment will be described.

  1. Flow injection with in-line reduction column and conductometric detection for determination of total inorganic nitrogen in soil.

    PubMed

    Yanu, Pattama; Jakmunee, Jaroon

    2015-11-01

    A cost effective flow injection (FI) conductometric system has been developed for determination of total inorganic nitrogen (TIN). The system is aimed for evaluation of nitrogen nutrient in soil for agricultural application. Inorganic nitrogen compounds were extracted from soil according to the standard method by using potassium chloride solution as an extractant, and the extracted solution was then injected into the FI system. Nitrate and nitrite are converted to ammonium ion by an in-line reduction column packed with a Devarda's alloy. A gas diffusion unit was incorporated into the FI system to separate ammonium ion from other ions in a donor stream by forming ammonia gas that can diffuse through a PTFE membrane to re-dissolve in an acceptor stream. Conductance of the acceptor stream was directly proportional to ammonium ion concentration. Various parameters affecting reduction efficiency of the column, e.g., column diameter, column packing procedure, and column length was investigated and optimized. A linear calibration graph in the range of 2.00-60.00 mg L(-1) N-NH4(+) (y=0.123x+0.039, R(2) =0.997) was obtained with a limit of detection of 0.47 mg L(-1). Sample throughput of 20 samples h(-1) was achieved. The result of developed method was correlated with total Kjeldahl nitrogen (TKN) obtained from the Kjeldahl digestion method. The proposed method could be used as an alternative method to the Kjeldahl method for determination of TIN in soil. PMID:26452820

  2. Liquid extraction surface analysis in-line coupled with capillary electrophoresis for direct analysis of a solid surface sample.

    PubMed

    Sung, In Hye; Lee, Young Woo; Chung, Doo Soo

    2014-08-01

    A surface-sampling technique of liquid extraction surface analysis (LESA) was in-line coupled with capillary electrophoresis (CE) to expand the specimen types for CE to solid surfaces. The new direct surface analysis method of LESA-CE was applied to the determination of organophosphorus pesticides, including glufosinate-ammonium, aminomethylphosphonic acid, and glyphosate on the external surface of a fruit such as apple. Without any sample pretreatment, the analytes sprayed on the surface of a half apple were directly extracted into a liquid microjunction formed by dispensing the extractant from the inlet tip of a separation capillary. After extraction, the analytes were derivatized in-capillary with a fluorophore 4-fluoro-7-nitro-2,1,3-benzoxadiazole and analyzed with CE-laser induced fluorescence (LIF). The limits of detection for glufosinate-ammonium, aminomethylphosphonic acid, and glyphosate were 2.5, 1, and 10ppb, respectively, which are at least 20 times lower than the tolerance limits established by the U.S. Environmental Protection Agency. Thus, we demonstrated that LESA-CE is a quite sensitive and convenient method to determine analytes on a solid surface avoiding the dilution from sample pretreatment procedures including homogenization of a bulk sample. PMID:25064242

  3. MRI compatibility of position-sensitive photomultiplier depth-of-interaction PET detectors modules for in-line multimodality preclinical studies

    NASA Astrophysics Data System (ADS)

    Vaquero, J. J.; Sánchez, J. J.; Udías, J. M.; Cal-González, J.; Desco, M.

    2013-02-01

    This work addresses the feasibility of a small-animal, in-line PET/MR system based on Position-Sensitive Photo Multiplier Tubes (PS-PMTs). To this end, we measured the effects of static magnetic fields on the PS-PMTs performance in order to explore the minimal tandem separation between the PET and MR subsystems to preserve their respective performances. We concluded that it is possible to achieve minimal degradation of the PET scanner performance (after a system recalibration) if the magnetic field strength influencing the PET detectors is less than 1 mT and if it is oriented perpendicularly to the longitudinal axis of the tube. Therefore, we predict that it will be possible to maintain the PET image quality if it is placed outside the 1 mT line.

  4. Optical transmission measurements for in-line monitoring of turbid oil-water emulsions

    NASA Astrophysics Data System (ADS)

    Metz, Philipp; Dopf, Katja; Aichholz, Markus; Riedel, Boris; Lemmer, Uli; Freudig, Barbara; Zimmermann, Clifton; Gerken, Martina

    2014-05-01

    For absorbing media the concentration may be calculated directly from the optical transmission following the logarithmic dependence given in the Lambert-Beer law. Due to multiple scattering events in oil-water emulsions (e.g. milk, cream, etc.), these exhibit a nonlinear relationship between the attenuation and the oil concentration. We demonstrate that for increasing oil content in oil-water emulsions the attenuation first increases, then levels out, and finally even decreases for a fat content of 60%. Single-wavelength optical transmission measurements are found to be well suited for the in-line monitoring of oil-water emulsions of fat contents below 20%, e.g., for the in-line fat content monitoring of milk. Using experiments and ray-tracing simulations we evaluate system optimization.

  5. The effect of in-line spacing of two cylinder groups on the Morison force coefficients

    SciTech Connect

    Smith, D.J.; Haritos, N.

    1996-12-31

    This paper describes some results from an experimental study undertaken in the University of Melbourne`s Michell Laboratory which has investigated the interference effect associated with closely spaced cylinder groups on the in-line Morison force coefficients. Previous experimental studies undertaken at the University of Melbourne identified that the closely spaced cylinder range, (spacing to diameter ratio less than 3), is critical to the determination of the Morison force coefficients for tandem cylinders. The current research extends the previous work conducted in the department by investigating in more detail the closely spaced cylinder regime whilst extending results into the drag dominant regime (Keulegan-Carpenter number > 20). Results presented herein are limited to the exploration of the effect of varying the spacing of two cylinder groups oriented in-line to the direction of the uni-directional waves.

  6. Hydrodynamic performance of multiple bodies swimming in an in-line configuration

    NASA Astrophysics Data System (ADS)

    Boschitsch, Birgitt; Dewey, Peter; Smits, Alexander

    2012-11-01

    Experiments are reported on a pair of airfoils that are harmonically pitched about their leading edges and arranged in an in-line configuration to determine the hydrodynamic effect of drafting behind a neighbor in unsteady bio-inspired propulsion. The thrust production, power consumption, and propulsive efficiency is independently measured for the leading and trailing airfoils at a Reynolds number of 2000 for a range of streamwise airfoil spacings, Strouhal numbers, and oscillation phase differential between the airfoils. To assess the wake interactions between the panels that lead to propulsive performances observed, digital particle image velocimetry (DPIV) is used. These results are compared to an airfoil swimming in an isolated configuration to identify the parameters that lead to a benefit (or detriment) when swimming in-line with a neighbor. The authors would like to acknowledge the generous support from the Office of Naval Research under Program Director Dr. Bob Brizzolara, MURI grant number N00014-08-1-0642.

  7. Dual-channel in-line digital holographic double random phase encryption

    PubMed Central

    Das, Bhargab; Yelleswarapu, Chandra S; Rao, D V G L N

    2012-01-01

    We present a robust encryption method for the encoding of 2D/3D objects using digital holography and virtual optics. Using our recently developed dual-plane in-line digital holography technique, two in-line digital holograms are recorded at two different planes and are encrypted using two different double random phase encryption configurations, independently. The process of using two mutually exclusive encryption channels makes the system more robust against attacks since both the channels should be decrypted accurately in order to get a recognizable reconstruction. Results show that the reconstructed object is unrecognizable even when the portion of the correct phase keys used during decryption is close to 75%. The system is verified against blind decryptions by evaluating the SNR and MSE. Validation of the proposed method and sensitivities of the associated parameters are quantitatively analyzed and illustrated. PMID:23471012

  8. Near-field ptychography: phase retrieval for inline holography using a structured illumination

    PubMed Central

    Stockmar, Marco; Cloetens, Peter; Zanette, Irene; Enders, Bjoern; Dierolf, Martin; Pfeiffer, Franz; Thibault, Pierre

    2013-01-01

    Inline holography is a common phase-contrast imaging method which uses free-space propagation to encode the phase signal into measured intensities. However, quantitative retrieval of the sample's image remains challenging, imposing constraints on the nature of the sample or on the propagation distance. Here, we present a way of simultaneously retrieving the sample's complex-valued transmission function and the incident illumination function from near-field diffraction patterns. The procedure relies on the measurement diversity created by lateral translations of the sample with respect to a structured illumination. The reconstruction approach, in essence identical to that employed in ptychography, is applied to hard X-ray synchrotron measurements and to simulations. Compared to other inline holography techniques, we expect near-field ptychography to reduce reconstruction artefacts by factoring out wavefront imperfections and relaxing constraints on the sample's scattering properties, thus ultimately improving the robustness of propagation-based X-ray phase tomography. PMID:23722622

  9. Optical inline measurement procedures for counting and sizing cells in bioprocess technology.

    PubMed

    Rudolph, Guido; Lindner, Patrick; Bluma, Arne; Joeris, Klaus; Martinez, Geovanni; Hitzmann, Bernd; Scheper, Thomas

    2009-01-01

    To observe and control cultivation processes, optical sensors are used increasingly. Important parameters for controlling such processes are cell count, cell size distribution, and the morphology of cells. Among turbidity measurement methods, imaging procedures are applied for determining these process parameters. A disadvantage of most previously developed imaging procedures is that they are only available offline which requires sampling. On the other hand, available imaging inline probes can so far only deliver a limited number of process parameters. This chapter presents new optical procedures for the inline determination of cell count, cell size distribution, and other parameters. In particular, by in situ microscopy an imaging procedure will be described which allows the determination of direct and nondirect cell parameters in real time without sampling. PMID:19609497

  10. In-line multiwavelength photometer for the determination of heavy metal concentrations

    SciTech Connect

    Bostick, D.T.; Strain, J.E.; Dixon, D.M.; McCue, D.D.; Bauer, M.L.

    1981-01-01

    An in-line photometer has been developed for continuous monitoring of uranium and plutonium concentrations in high radiation environments of nuclear fuel reprocessing plants. The instrument is equipped with multiple narrow band interference filters to monitor sample transmission in the 400- to 800-nm range. The filters are mounted in a rotating filter wheel which is located in front of a stationary tungsten halide light source. The monochromatic light from the respective optical filters is transmitted through a fiber optic cable of up to 10 m in length to the in-line sample flow cell located within the reprocessing area. A similar length of cable returns the optical signal to the photometer where the light intensity is detected with a photomultiplier tube, amplified, and processed with an LSI-11 computer system.

  11. Switchable in-line monitor for multi-dimensional multiplexed photonic integrated circuit.

    PubMed

    Chen, Guanyu; Yu, Yu; Ye, Mengyuan; Zhang, Xinliang

    2016-06-27

    A flexible monitor suitable for the discrimination of on-chip transmitted mode division multiplexed (MDM) and wavelength division multiplexed (WDM) signals is proposed and fabricated. By selectively extracting part of the incoming signals through the tunable wavelength and mode dependent drop filter, the in-line and switchable monitor can discriminate the wavelength, mode and power information of the transmitted signals. Being different from a conventional mode and wavelength demultiplexer, the monitor is specifically designed to ensure a flexible in-line monitoring. For demonstration, three mode and three wavelength multiplexed signals are successfully processed. Assisted by the integrated photodetectors (PDs), both the measured photo currents and eye diagrams validate the performance of the proposed device. The bit error ratio (BER) measurement results show less than 0.4 dB power penalty between different modes and ~2 dB power penalty for single wavelength and WDM cases under 10-9 BER level. PMID:27410636

  12. In-line image analysis on the effects of additives in batch cooling crystallization

    NASA Astrophysics Data System (ADS)

    Qu, Haiyan; Louhi-Kultanen, Marjatta; Kallas, Juha

    2006-03-01

    The effects of two potassium salt additives, ethylene diamine tetra acetic acid dipotassium salt (EDTA) and potassium pyrophosphate (KPY), on the batch cooling crystallization of potassium dihydrogen phosphate (KDP) were investigated. The crystal growth rates of certain crystal faces were determined from in-line images taken with a MTS particle image analysis (PIA) video microscope. An in-line image processing method was developed to characterize the size and shape of the crystals. The nucleation kinetics was studied by measurement of the metastable zone width and induction time. A significant promotion effect on both nucleation and growth of KDP was observed when EDTA was used as an additive. KPY, however, exhibited strong inhibiting impacts. The mechanism underlying the EDTA promotion effect on crystal growth was further studied with the 2-dimension nucleation model. It is shown that the presence of EDTA increased the density of adsorbed molecules of the crystallizing solute on the surface of the crystal.

  13. Multi-point vibrometer based on high-speed digital in-line holography.

    PubMed

    Poittevin, Julien; Picart, Pascal; Faure, Charly; Gautier, François; Pézerat, Charles

    2015-04-10

    This paper describes a digital holographic setup based on in-line holography and a high-speed recording to get a multipoint vibrometer. The use of a high-speed sensor leads to specificities that enable the in-line configuration to be used. The case of transient vibrations is investigated through a full simulation of the holographic process. The simulation shows that the first instants are critical since distortion may occur, resulting in errors in the phase measurement. Experimental results are provided by exciting an aluminum beam with a transient signal. A comparison with the velocity measured by a pointwise vibrometer is provided. Frequency response functions are extracted and the experimental results confirm the ability of the method to provide full-field contactless measurements at the high-speed time scale evolution of the vibration. PMID:25967302

  14. Separation techniques.

    PubMed

    Duke, T

    1998-10-01

    The past two years have seen continued development of capillary electrophoresis methods. The separation performance of flowable sieving media now equals, and in some respects exceeds, that provided by gels. The application of microfabrication techniques to separation science is gaining pace. There is a continuing trend towards miniaturization and integration of separation with preparative or analytical steps. Innovative separation methods based on microfabrication technology include electrophoresis in purpose-designed molecular sieves, dielectric, trapping using microelectrodes, and force-free motion in Brownian ratchets. PMID:9818184

  15. In-line measurement of high temperature dielectric constant in the process of sintering

    SciTech Connect

    Zhou Jian; Cheng Jiping; Tang Yuling; Qiu Jinyu

    1996-12-31

    In this paper, a resonant cavity method is developed and some experimental results for measuring dielectric constants of ceramic samples (e.g., Al{sub 2}O{sub 3}) under different sintering temperatures are reported. The experiments show that this method has higher precision and good prospects of in-line monitoring the high temperature dielectric constant in the process of raising the temperature of the samples. These results provide some scientific experimental basis for physical research of ceramic materials.

  16. In-line fuzing development for tactical airfield attack munition (TAAM)

    SciTech Connect

    Morrison, J.J.

    1981-03-18

    The shock-hardened new-concept safing, arming, and in-line fuzing system developed for US Air Force modular weapons is being advanced for the Tactical Airfield Attack Munition (TAAM) as an alternate fuzing system. The high power slapper detonator system is being reduced in volume by an approximate factor of 10 and the energy by a factor of 3. In addition, the fuze has the capability of functioning after many hours of delay to provide area-denial capabilities.

  17. Generalized in-line digital holographic technique based on intensity measurements at two different planes

    NASA Astrophysics Data System (ADS)

    Situ, Guohai; Ryle, James P.; Gopinathan, Unnikrishnan; Sheridan, John T.

    2008-02-01

    In-line digital holography based on two-intensity measurements [Zhang et al. Opt. Lett. 29, 1787 (2004)], is modified by introducing a π shifting in the reference phase. Such an improvement avoids the assumption that the object beam must be much weaker than the reference beam in strength and results in a simplified experimental implementation. Computer simulations and optical experiments are carried out to validate the method, which we refer to as position-phase-shifting digital holography.

  18. In-line pressure-flow module for in vitro modelling of haemodynamics and biosensor validation

    NASA Technical Reports Server (NTRS)

    Koenig, S. C.; Schaub, J. D.; Ewert, D. L.; Swope, R. D.; Convertino, V. A. (Principal Investigator)

    1997-01-01

    An in-line pressure-flow module for in vitro modelling of haemodynamics and biosensor validation has been developed. Studies show that good accuracy can be achieved in the measurement of pressure and of flow, in steady and pulstile flow systems. The model can be used for development, testing and evaluation of cardiovascular-mechanical-electrical anlogue models, cardiovascular prosthetics (i.e. valves, vascular grafts) and pressure and flow biosensors.

  19. Simple in-line postcolumn oxidation and derivatization for the simultaneous analysis of ascorbic and dehydroascorbic acids in foods.

    PubMed

    Bognár, A; Daood, H G

    2000-04-01

    A new analytical procedure for the simultaneous determination of L-ascorbic acid (AA), isoascorbic acid (IAA), L-dehydroascorbic acid (DHAA), and isodehydroascorbic acid (IDHAA) in food by high-performance liquid chromatography (HPLC) is developed. After separation on an HPLC column, an in-line oxidation of AA and IAA to DHAA and IDHAA, respectively, is performed on a short column of activated charcoal. The dehydroascorbic acids are derivatized with a 1,2-phenylenediamine solution in a heated capillary Tefzel reactor into fluorescent quinoxaline compounds and monitored fluorometrically. The chromatographic method provides good separation of LAA, LDHAA, and their diastereoisomers in a relatively short time (-10 min). After optimization of postcolumn derivatization conditions, calibration runs and recovery tests are performed. The fluorescent response in terms of peak area is highly proportional to the concentration of all derivatives examined over a range of 0.1 to 100 microg/mL solution for LAA, LDHAA, IAA, and IDHAA. Recoveries were in the range of 97 to 103%. The detection limit is 0.1 mg of each ascorbic acid derivative per 100 g food. A wide variety of foods (fruits, fruit juices, vegetables, vegetable products, milk, liver, and sausage) are analyzed by the developed procedure. The Vitamin C (LAA and LDHA) contents determined according to the present analytical method are in the same order of magnitude as the result of precolumn derivatization and the fluorometric methods. The described method is a highly specific procedure for determining Vitamin C in food. It is simple to handle, only slightly susceptible to disturbance, perfectly suitable for serial determinations, and yields reproducible results. PMID:10766483

  20. In-line phase contrast micro-CT reconstruction for biomedical specimens.

    PubMed

    Fu, Jian; Tan, Renbo

    2014-01-01

    X-ray phase contrast micro computed tomography (micro-CT) can non-destructively provide the internal structure information of soft tissues and low atomic number materials. It has become an invaluable analysis tool for biomedical specimens. Here an in-line phase contrast micro-CT reconstruction technique is reported, which consists of a projection extraction method and the conventional filter back-projection (FBP) reconstruction algorithm. The projection extraction is implemented by applying the Fourier transform to the forward projections of in-line phase contrast micro-CT. This work comprises a numerical study of the method and its experimental verification using a biomedical specimen dataset measured at an X-ray tube source micro-CT setup. The numerical and experimental results demonstrate that the presented technique can improve the imaging contrast of biomedical specimens. It will be of interest for a wide range of in-line phase contrast micro-CT applications in medicine and biology. PMID:24211924

  1. In-Line Monitoring of a Pharmaceutical Pan Coating Process by Optical Coherence Tomography.

    PubMed

    Markl, Daniel; Hannesschläger, Günther; Sacher, Stephan; Leitner, Michael; Buchsbaum, Andreas; Pescod, Russel; Baele, Thomas; Khinast, Johannes G

    2015-08-01

    This work demonstrates a new in-line measurement technique for monitoring the coating growth of randomly moving tablets in a pan coating process. In-line quality control is performed by an optical coherence tomography (OCT) sensor allowing nondestructive and contact-free acquisition of cross-section images of film coatings in real time. The coating thickness can be determined directly from these OCT images and no chemometric calibration models are required for quantification. Coating thickness measurements are extracted from the images by a fully automated algorithm. Results of the in-line measurements are validated using off-line OCT images, thickness calculations from tablet dimension measurements, and weight gain measurements. Validation measurements are performed on sample tablets periodically removed from the process during production. Reproducibility of the results is demonstrated by three batches produced under the same process conditions. OCT enables a multiple direct measurement of the coating thickness on individual tablets rather than providing the average coating thickness of a large number of tablets. This gives substantially more information about the coating quality, that is, intra- and intertablet coating variability, than standard quality control methods. PMID:26045441

  2. Inline Modeling of Cross-Beam Energy Transfer and Raman Scattering in NIF Hohlraums

    NASA Astrophysics Data System (ADS)

    Strozzi, David; Bailey, D. S.; Thomas, C. A.; Sepke, S. M.; Kerbel, G. D.; Michel, P.; Divol, L.; Jones, O. S.

    2015-11-01

    Inline models of cross-beam energy transfer (CBET) and stimulated Raman Scattering (SRS) have been added to the radiation-hydrodynamics codes Hydra and Lasnex. Both processes are important in hohlraums with high gas fill density, particularly for implosion symmetry. Coupled-mode equations are solved along laser ray paths for both models. The inline model shows the SRS gain rate exceeds that of SRS light absorption along most of the laser ray path, and most SRS light escapes the target. Most SRS-driven Langmuir wave power is deposited slightly inside the laser entrance hole (LEH), which reduces how much inner-beam power reaches the equator. This also makes the LEH hotter, which affects CBET. Compared to removing SRS power from the incident laser, the inline SRS model does not change total x-ray drive but makes the drive stronger from the poles than the equatorial waist. This reduces the need to artificially clamp CBET in order to match implosion shape data, which has historically been needed for high gas fill hohlraums. We are applying the models to a set of NIF shots with varying gas fill densities. Work performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

  3. Relationship between in-line viscosity and Bostwick measurement during ketchup production.

    PubMed

    McCarthy, Kathryn L; McCarthy, Michael J

    2009-08-01

    The Bostwick consistometer remains an integral part of assessing the consistency of tomato products in the factory. This work addresses the blending of tomato pastes, packed at different Bostwick readings, for use in tomato ketchup production. The objective of this study was to correlate in-line viscosity measurements of 12 degrees Bx tomato concentrates to final product quality. Five blends of tomato concentrate were prepared by blending 2 pastes and diluting the mixture to a soluble solids level of 12 degrees Bx. In-line viscometry measurements at process temperature were made using magnetic resonance viscometry. The resulting Herschel-Bulkley parameters were used to evaluate an apparent viscosity at a characteristic shear rate. The apparent viscosity and Bostwick measurement for the blends were correlated based on a gravity current flow analysis, yielding a coefficient of determination of over 0.99. Ketchup was made from the tomato concentrate blends at 3 levels of natural tomato soluble solids (NTSS). The ketchup Bostwick measurement was then correlated to the ratio of (eta/rho)(-1/5) of the 12 degrees Bx tomato concentrate yielding coefficients of determination of 0.97, 0.97, and 0.91 for NTSS levels of 6%, 7%, and 7.8%, respectively. This study demonstrates that final product quality can be predicted from in-line viscosity measurements of an intermediate product. PMID:19723191

  4. Inline Modeling of Cross-Beam Energy Transfer and Backscatter in Hohlraums

    NASA Astrophysics Data System (ADS)

    Strozzi, D. J.; Sepke, S. M.; Kerbel, G. D.; Michel, P.; Marinak, M. M.; Jones, O. S.

    2014-10-01

    NIF Ignition experiments with gas-filled hohlraums use significant cross-beam energy transfer (CBET) to control implosion symmetry. They also display substantial stimulated Raman backscatter (SRS) from inner laser beams, and associated ``hot'' electrons. The radiation-hydrodynamics code HYDRA has been extended to include inline models for CBET and SRS. Coupled-mode equations in the strong damping limit (with linear, kinetic gain rates) are solved along the entire path of incident laser rays. Driven ion-acoustic and Langmuir waves, and inverse-bremsstrahlung absorption, are treated. The inline model includes heating by CBET-driven ion waves, which reduces subsequent CBET. SRS developing inside the target leads to more heating of the underdense fill - and more depletion of the inner beams reaching the hohlraum wall - than removing the escaping SRS light from the incident laser. Thus, SRS also modifies the plasma conditions so as to limit CBET. We compare inline results with post-processing CBET calculations on plasma conditions from simulations that do not include CBET or SRS. Prepared by LLNSL under Contract DE-AC52-07NA27344.

  5. Phantom study based on a high-energy in-line phase contrast tomosynthesis prototype

    NASA Astrophysics Data System (ADS)

    Wu, Di; Yan, Aimin; Li, Yuhua; Chen, Wei R.; Wu, Xizeng; Liu, Hong

    2014-02-01

    The objective of this research is to demonstrate an in-line phase contrast tomosynthesis prototype operated under high x-ray tube voltage, and a phantom study was conducted to characterize the potentials of this system. The prototype is based on an in-line phase contrast system accompanying with digital tomosynthesis imaging mechanism; and the tube voltage is operated at 120 kVp. A phantom study was conducted by using a custom-designed fish bone phantom to demonstrate the ability of this imaging system in edge enhancement and noise suppression. As the result, edge enhancement could be observed on the in-plane slices by plotting and comparing the intensity profiles with DTS images. As employing phase retrieval method onto the original angular projections could dramatically improve the image quality in edge enhancement, 3D imaging box was preliminarily constructed by using reconstructed in-plane slices acquired with PAD phase retrieval. As expected, high-energy in-line phase contrast tomosynthesis imaging system shows its potentials in edge enhancement and noise suppression by introducing phase retrieval method. Dose studies and perfecting photon energies and phantom designs will be our future interest.

  6. In-line quality control of moving objects by means of spectral-domain OCT

    NASA Astrophysics Data System (ADS)

    Markl, Daniel; Hannesschläger, Günther; Buchsbaum, Andreas; Sacher, Stephan; Khinast, Johannes G.; Leitner, Michael

    2014-08-01

    In-line quality control of intermediate and final products is essential in various industries. This may imply determining the thickness of a foil or evaluating the homogeneity of coating applied to a pharmaceutical tablet. Such a qualitative and quantitative monitoring in a depth-resolved manner can be accomplished using optical coherence tomography (OCT). In-line quality control based on OCT requires additional consideration of motion effects for the system design as well as for data interpretation. This study focuses on transverse motion effects that can arise in spectral-domain (SD-) OCT systems. The impact of a transverse movement is analyzed for a constant relative speed difference up to 0.7 m/s between sample and sensor head. In particular, transverse motion is affecting OCT system properties such as the beam displacement (distance between adjacent A-scans) and transverse resolution. These properties were evaluated theoretically and experimentally for OCT images of a resolution target and pharmaceutical film-coated tablets. Both theoretical and experimental analyses highlight the shift of the transverse resolution limiting factor from the optics to the beam displacement above a relative speed difference between sensor head and sample of 0.42 m/s (for the presented SD-OCT setup). Speeds above 0.4 m/s are often demanded when monitoring industrial processes, such as a coating process when producing film-coated tablets. This emphasizes the importance of a fast data acquisition when using OCT as in-line quality control tool.

  7. Hydrogen separation process

    DOEpatents

    Mundschau, Michael; Xie, Xiaobing; Evenson, IV, Carl; Grimmer, Paul; Wright, Harold

    2011-05-24

    A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to a hydrogen separation membrane system comprising a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to an integrated water gas shift/hydrogen separation membrane system wherein the hydrogen separation membrane system comprises a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for pretreating a membrane, comprising: heating the membrane to a desired operating temperature and desired feed pressure in a flow of inert gas for a sufficient time to cause the membrane to mechanically deform; decreasing the feed pressure to approximately ambient pressure; and optionally, flowing an oxidizing agent across the membrane before, during, or after deformation of the membrane. A method of supporting a hydrogen separation membrane system comprising selecting a hydrogen separation membrane system comprising one or more catalyst outer layers deposited on a hydrogen transport membrane layer and sealing the hydrogen separation membrane system to a porous support.

  8. Composite hydrogen separation element and module

    DOEpatents

    Edlund, D.J.

    1996-03-12

    There are disclosed improvements in multicomponent composite metal membranes useful for the separation of hydrogen, the improvements comprising the provision of a flexible porous intermediate layer between a support layer and a nonporous hydrogen-permeable coating metal layer, and the provision of a textured coating metal layer. 15 figs.

  9. Effects of Cycling vs. Running Training on Endurance Performance in Preparation for Inline Speed Skating.

    PubMed

    Stangier, Carolin; Abel, Thomas; Hesse, Clemens; Claen, Stephanie; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K

    2016-06-01

    Stangier, C, Abel, T, Hesse, C, Claßen, S, Mierau, J, Hollmann, W, and Strüder, HK. Effects of cycling vs. running training on endurance performance in preparation for inline speed skating. J Strength Cond Res 30(6): 1597-1606, 2016-Winter weather conditions restrict regular sport-specific endurance training in inline speed skating. As a result, this study was designed to compare the effects of cycling and running training programs on inline speed skaters' endurance performance. Sixteen (8 men, 8 women) high-level athletes (mean ± SD 24 ± 8 years) were randomly assigned to 1 of 2 groups (running and cycling). Both groups trained twice a week for 8 weeks, one group on a treadmill and the other on a cycle ergometer. Training intensity and duration was individually calculated (maximal fat oxidation: ∼52% of V[Combining Dot Above]O2peak: 500 kcal per session). Before and after the training intervention, all athletes performed an incremental specific (inline speed skating) and 1 nonspecific (cycling or running) step test according to the group affiliation. In addition to blood lactate concentration, oxygen uptake (V[Combining Dot Above]O2), ventilatory equivalent (VE/V[Combining Dot Above]O2), respiratory exchange ratio (RER), and heart rate were measured. The specific posttest revealed significantly increased absolute V[Combining Dot Above]O2peak values (2.9 ± 0.4, 3.4 ± 0.7, p = 0.01) and submaximal V[Combining Dot Above]O2 values (p ≤ 0.01). VE/V[Combining Dot Above]O2 and RER significantly decreased at maximal (46.6 ± 6.6, 38.5 ± 3.4, p = 0.005; 1.1 ± 0.03, 1.0 ± 0.04, p = 0.001) and submaximal intensities (p ≤ 0.04). None of the analysis revealed a significant group effect (p ≥ 0.15). The results indicate that both cycling vs. running exercise at ∼52% of V[Combining Dot Above]O2peak had a positive effect on the athletes' endurance performance. The increased submaximal V[Combining Dot Above]O2 values indicate a reduction in athletes' inline speed

  10. Modelling Layer parallel stylolites

    NASA Astrophysics Data System (ADS)

    Koehn, Daniel; Pataki Rood, Daisy; Beaudoin, Nicolas

    2016-04-01

    We modeled the geometrical roughening of mainly layer-dominated stylolites in order to understand their structural evolution, to present an advanced classification of stylolite shapes and to relate this classification to chemical compaction and stylolite sealing capabilities. Our simulations show that layer-dominated stylolites can grow in three distinct stages, an initial slow nucleation, a fast layer-pinning phase and a final freezing stage if the layer dissolves completely during growth. Dissolution of the pinning layer and thus destruction of the compaction tracking capabilities is a function of the background noise in the rock and the dissolution rate of the layer itself. Low background noise needs a slower dissolving layer for pinning to be successful but produces flatter teeth than higher background noise. We present an advanced classification based on our simulations and separate stylolites into four classes: rectangular layer type, seismogram pinning type, suture/sharp peak type and simple wave-like type.

  11. Char separator

    DOEpatents

    Matthews, Francis T.

    1979-01-01

    Particulates removed from the flue gases produced in a fluidized-bed furnace are separated into high-and low-density portions. The low-density portion is predominantly char, and it is returned to the furnace or burned in a separate carbon burnup cell. The high-density portion, which is predominantly limestone products and ash, is discarded or reprocessed. According to another version, the material drained from the bed is separated, the resulting high-and low-density portions being treated in a manner similar to that in which the flue-gas particulates are treated.

  12. CENTRIFUGAL SEPARATORS

    DOEpatents

    Skarstrom, C.

    1959-03-10

    A centrifugal separator is described for separating gaseous mixtures where the temperature gradients both longitudinally and radially of the centrifuge may be controlled effectively to produce a maximum separation of the process gases flowing through. Tbe invention provides for the balancing of increases and decreases in temperature in various zones of the centrifuge chamber as the result of compression and expansions respectively, of process gases and may be employed effectively both to neutralize harmful temperature gradients and to utilize beneficial temperaturc gradients within the centrifuge.

  13. Novel Separation of Actinides

    SciTech Connect

    Mariella, R

    2011-02-17

    The separation of actinides and other elements of interest for nuclear forensics and threat reduction is currently performed using decades-old chemistries and ion-exchange columns. We propose to determine the technical feasibility of a novel method for separating actinide ions in solution. This method is based upon isotachophoresis (ITP), which has been applied in the purification of pharmaceuticals and other biochemical applications. This technique has the potential to separate inorganic ions more effectively than existing methods, which is key to analyzing very small samples. We will perform a quantitative assessment of the effectiveness of specific isotachophoretic approaches including predicting the physical and chemical properties, such as ion mobility, of inorganic ions under specific solvent conditions using a combination of ab initio calculations and semi-empirical methods. We expect to obtain a thorough understanding of the analytical systems parameters under which ITP is most effective for the separation of inorganic samples, including the influence of the double layer surrounding actinide ions, the Debye length for different ions and ion complexes, and Debye-Hueckel limits. Inorganic separations are key to nuclear forensics for countering terrorism and nuclear proliferation. If found to be feasible and potentially superior to currently used separation approaches, ITP could provide the conceptual basis for an improved means to separate samples of nuclear explosion debris for nuclear forensic analysis, in support of the Laboratory's missions in homeland and national security.

  14. Stereoisomers Separation

    NASA Astrophysics Data System (ADS)

    Wieczorek, Piotr

    The use of capillary electrophoresis for enantiomer separation and optical purity determination is presented. The contents start with basic information about the nature of stereoizomers and the mechanism of enantioseparation using capillary electrophoresis techniques. The molecules to be separated show identical chemical structure and electrochemical behavior. Therefore, the chiral recognition of enantiomers is possible only by bonding to chiral selector and the separation based on very small differences in complexation energies of diastereomer complexes formed. This method is useful for this purpose due to the fact that different compounds can be used as chiral selectors. The mostly used chiral selectors like cyclodextrins, crown ethers, chiral surfactants, macrocyclic antibiotics, transition metal complexes, natural, and synthetic polymers and their application for this purpose is also discussed. Finally, examples of practical applications of electromigration techniques for enantiomers separation and determination are presented.

  15. Ares I Stage Separation Test

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Under the goals of the Vision for Space Exploration, Ares I is a chief component of the cost-effective space transportation infrastructure being developed by NASA's Constellation Program. This transportation system will safely and reliably carry human explorers back to the moon, and then onward to Mars and other destinations in the solar system. The Ares I effort includes multiple project element teams at NASA centers and contract organizations around the nation, and is managed by the Exploration Launch Projects Office at NASA's Marshall Space Flight Center (MFSC). ATK Launch Systems near Brigham City, Utah, is the prime contractor for the first stage booster. ATK's subcontractor, United Space Alliance of Houston, is designing, developing and testing the parachutes at its facilities at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center in Houston hosts the Constellation Program and Orion Crew Capsule Project Office and provides test instrumentation and support personnel. Together, these teams are developing vehicle hardware, evolving proven technologies, and testing components and systems. Their work builds on powerful, reliable space shuttle propulsion elements and nearly a half-century of NASA space flight experience and technological advances. Ares I is an inline, two-stage rocket configuration topped by the Crew Exploration Vehicle, its service module, and a launch abort system. In this HD video image, an Ares I x-test involves the upper stage separating from the first stage. This particular test was conducted at the NASA Langley Research Center in July 2007. (Highest resolution available)

  16. Battery separator

    SciTech Connect

    Balouskus, R.A.; Feinberg, S.C.; Lundquist, J.T.; Lundsager, C.B.

    1980-09-23

    A battery separator and a method of forming the same is described. The separator has good electrical conductivity and a high degree of inhibition to dendrite formation, and is in the form of a thin sheet formed from a substantially uniform mixture of a thermoplastic rubber and a filler in a volume ratio of from about 1:0.15 to 1:0.6. The thermoplastic rubber is preferably a styrene/elastomer/styrene block copolymer.

  17. Product separator

    DOEpatents

    Welsh, Robert A.; Deurbrouck, Albert W.

    1976-01-20

    A secondary light sensitive photoelectric product separator for use with a primary product separator that concentrates a material so that it is visually distinguishable from adjacent materials. The concentrate separation is accomplished first by feeding the material onto a vibratory inclined surface with a liquid flow, such as a wet concentrating table. Vibrations generally perpendicular to the stream direction of flow cause the concentrate to separate from its mixture according to its color. When the concentrate and its surrounding stream reach the recovery end of the table, a detecting device notes the line of color demarcation and triggers a signal if it differs from a normal condition. If no difference is noted nothing moves on the second separator. However, if a difference is detected in the constant monitoring of the color line's location, a product splitter and recovery unit normally positioned near the color line at the recovery end, moves to a new position. In this manner the selected separated concentrate is recovered at a maximum rate regardless of variations in the flow stream or other conditions present.

  18. Two-dimensional separated flows

    NASA Astrophysics Data System (ADS)

    Gersten, K.

    The state of the art of asymptotic theory is discussed with respect to incompressible two-dimensional separated flows. As an example, the flow over an indented flat plate is considered for two cases: a small separation bubble within the lower part of the boundary layer, and the 'catastrophic' separation of the whole boundary layer with a large recirculating eddy. Separation means failure of Prandtl's boundary layer theory, and alternate theories are required. An example of this is shown in the calculation of circulation in the dent according to triple-deck theory. The free-streamline theory approach is used to examine the indented flat plate and the flow past a circular cylinder. Attention is also given to flow control by continuous injection, combined forced and free convection, unsteady laminar flows, and laminar flows.

  19. Map Separates

    USGS Publications Warehouse

    U.S. Geological Survey

    2001-01-01

    U.S. Geological Survey (USGS) topographic maps are printed using up to six colors (black, blue, green, red, brown, and purple). To prepare your own maps or artwork based on maps, you can order separate black-and-white film positives or negatives for any color printed on a USGS topographic map, or for one or more of the groups of related features printed in the same color on the map (such as drainage and drainage names from the blue plate.) In this document, examples are shown with appropriate ink color to illustrate the various separates. When purchased, separates are black-and-white film negatives or positives. After you receive a film separate or composite from the USGS, you can crop, enlarge or reduce, and edit to add or remove details to suit your special needs. For example, you can adapt the separates for making regional and local planning maps or for doing many kinds of studies or promotions by using the features you select and then printing them in colors of your choice.

  20. Layer-separated MoS2 bearing reduced graphene oxide formed by an in situ intercalation-cum-anchoring route mediated by Co(OH)2 as a Pt-free electrocatalyst for oxygen reduction.

    PubMed

    Illathvalappil, Rajith; Unni, Sreekuttan M; Kurungot, Sreekumar

    2015-10-28

    A significant improvement in the electrochemical oxygen reduction reaction (ORR) activity of molybdenum sulphide (MoS2) could be accomplished by its layer separated dispersion on graphene mediated by cobalt hydroxide (Co(OH)2) through a hydrothermal process (Co(OH)2-MoS2/rGO). The activity makeover in this case is found to be originated from a controlled interplay of the favourable modulations achieved in terms of electrical conductivity, more exposure of the edge planes of MoS2 and a promotional role played by the coexistence of Co(OH)2 in the proximity of MoS2. Co(OH)2-MoS2/rGO displays an oxygen reduction onset potential of 0.855 V and a half wave potential (E1/2) of 0.731 V vs. RHE in 0.1 M KOH solution, which are much higher than those of the corresponding values (0.708 and 0.349 V, respectively) displayed by the as synthesized pristine MoS2 (P-MoS2) under identical experimental conditions. The Tafel slope corresponding to oxygen reduction for Co(OH)2-MoS2/rGO is estimated to be 63 mV dec(-1) compared to 68 mV dec(-1) displayed by the state-of-the-art Pt/C catalyst. The estimated number of electrons transferred during oxygen reduction for Co(OH)2-MoS2/rGO is in the range of 3.2-3.6 in the potential range of 0.77 V to 0.07 V, which again stands out as valid evidence on the much favourable mode of oxygen reduction accomplished by the system compared to its pristine counterpart. Overall, the present study, thus, demonstrates a viable strategy of tackling the inherent limitations, such as low electrical conductivity and limited access to the active sites, faced by the layered structures like MoS2 to position them among the group of potential Pt-free electrocatalysts for oxygen reduction. PMID:26399300

  1. Multiple layer insulation cover

    DOEpatents

    Farrell, James J.; Donohoe, Anthony J.

    1981-11-03

    A multiple layer insulation cover for preventing heat loss in, for example, a greenhouse, is disclosed. The cover is comprised of spaced layers of thin foil covered fabric separated from each other by air spaces. The spacing is accomplished by the inflation of spaced air bladders which are integrally formed in the cover and to which the layers of the cover are secured. The bladders are inflated after the cover has been deployed in its intended use to separate the layers of the foil material. The sizes of the material layers are selected to compensate for sagging across the width of the cover so that the desired spacing is uniformly maintained when the cover has been deployed. The bladders are deflated as the cover is stored thereby expediting the storage process and reducing the amount of storage space required.

  2. B -meson decay constants from 2+1 -flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks

    SciTech Connect

    Christ, N. H.; Flynn, J. M.; Izubuchi, T.; Kawanai, T.; Lehner, C.; Soni, A.; Van de Water, R. S.; Witzel, O.

    2015-03-01

    We calculate the <inline-formula>inline">Binline-formula>-meson decay constants <inline-formula>inline">fBinline-formula>, <inline-formula>inline">fBsinline-formula>, and their ratio in unquenched lattice QCD using domain-wall light quarks and relativistic <inline-formula>inline">binline-formula> quarks. We use gauge-field ensembles generated by the RBC and UKQCD collaborations using the domain-wall fermion action and Iwasaki gauge action with three flavors of light dynamical quarks. We analyze data at two lattice spacings of <inline-formula>inline">a0.11inline-formula>, 0.086 fm with unitary pion masses as light as <inline-formula>inline">Mπ290MeVinline-formula>; this enables us to control the extrapolation to the physical light-quark masses and continuum. For the <inline-formula>inline">binline-formula> quarks we use the anisotropic clover action with the relativistic heavy-quark interpretation, such that discretization errors from the heavy-quark action are of the same size as from the light-quark sector. We renormalize the

  3. Flow separation detector

    NASA Technical Reports Server (NTRS)

    Mateer, G. C.; Brosh, A. (Inventor)

    1977-01-01

    An arrangement for sensing the fluid separation along a surface which employs a thermally insulating element having a continuous surface blending into and forming a part of the fluid flow surface is described. A sudden decrease in the temperature of the downstream sensor conductor and concomitant increase in the temperature of the upstream sensor conductor is an indication of the separation. When the temperatures are returned to the state achieved during normal flow, the indicator thereby indicates the normal, attached fluid flow. The conductors may be, for example, wires or thin films, and should be within the viscous sub-layer of the expected fluid flow. A single heater and several pairs of sensors and corresponding sensor conductors may be used to detect not only the fluid flow and the separation, but the direction of the fluid flow, over the fluid flow surface.

  4. Isotope separation

    DOEpatents

    Bartlett, Rodney J.; Morrey, John R.

    1978-01-01

    A method and apparatus is described for separating gas molecules containing one isotope of an element from gas molecules containing other isotopes of the same element in which all of the molecules of the gas are at the same electronic state in their ground state. Gas molecules in a gas stream containing one of the isotopes are selectively excited to a different electronic state while leaving the other gas molecules in their original ground state. Gas molecules containing one of the isotopes are then deflected from the other gas molecules in the stream and thus physically separated.

  5. ISOTOPE SEPARATORS

    DOEpatents

    Bacon, C.G.

    1958-08-26

    An improvement is presented in the structure of an isotope separation apparatus and, in particular, is concerned with a magnetically operated shutter associated with a window which is provided for the purpose of enabling the operator to view the processes going on within the interior of the apparatus. The shutier is mounted to close under the force of gravity in the absence of any other force. By closing an electrical circuit to a coil mouated on the shutter the magnetic field of the isotope separating apparatus coacts with the magnetic field of the coil to force the shutter to the open position.

  6. In-line multipoint near-infrared spectroscopy for moisture content quantification during freeze-drying.

    PubMed

    Kauppinen, Ari; Toiviainen, Maunu; Korhonen, Ossi; Aaltonen, Jaakko; Järvinen, Kristiina; Paaso, Janne; Juuti, Mikko; Ketolainen, Jarkko

    2013-02-19

    During the past decade, near-infrared (NIR) spectroscopy has been applied for in-line moisture content quantification during a freeze-drying process. However, NIR has been used as a single-vial technique and thus is not representative of the entire batch. This has been considered as one of the main barriers for NIR spectroscopy becoming widely used in process analytical technology (PAT) for freeze-drying. Clearly it would be essential to monitor samples that reliably represent the whole batch. The present study evaluated multipoint NIR spectroscopy for in-line moisture content quantification during a freeze-drying process. Aqueous sucrose solutions were used as model formulations. NIR data was calibrated to predict the moisture content using partial least-squares (PLS) regression with Karl Fischer titration being used as a reference method. PLS calibrations resulted in root-mean-square error of prediction (RMSEP) values lower than 0.13%. Three noncontact, diffuse reflectance NIR probe heads were positioned on the freeze-dryer shelf to measure the moisture content in a noninvasive manner, through the side of the glass vials. The results showed that the detection of unequal sublimation rates within a freeze-dryer shelf was possible with the multipoint NIR system in use. Furthermore, in-line moisture content quantification was reliable especially toward the end of the process. These findings indicate that the use of multipoint NIR spectroscopy can achieve representative quantification of moisture content and hence a drying end point determination to a desired residual moisture level. PMID:23351045

  7. 40 CFR 63.1345 - Emissions limits for affected sources other than kilns; in-line kiln/raw mills; clinker coolers...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Emissions limits for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers... for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and...

  8. 40 CFR 63.1345 - Emissions limits for affected sources other than kilns; in-line kiln/raw mills; clinker coolers...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Emissions limits for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers... for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and...

  9. 40 CFR 63.1348 - Standards for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... than kilns; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers; and raw...; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers; and raw and finish mills. The owner or operator of each new or existing raw material, clinker, or finished...

  10. Structural design of an in-line bolted joint for the space shuttle solid rocket motor case segments

    NASA Technical Reports Server (NTRS)

    Dorsey, John T.; Stein, Peter A.; Bush, Harold G.

    1987-01-01

    Results of a structural design study of an in-line bolted joint concept which can be used to assemble Space Shuttle Solid Rocket Motor (SRM) case segments are presented. Numerous parametric studies are performed to characterize the in-line bolted joint behavior as major design variables are altered, with the primary objective always being to keep the inside of the joint (where the O-rings are located) closed during the SRM firing. The resulting design has 180 1-inch studs, an eccentricity of -0.5 inch, a flange thickness of 3/4 inch, a bearing plate thickness of 1/4 inch, and the studs are subjected to a preload which is 70% of ultimate. The mass penalty per case segment joint for the in-line design is 346 lbm more than the weight penalty for the proposed capture tang fix.

  11. Investigation Of In-Line Monitoring Options At H Canyon/HB Line For Plutonium Oxide Production

    SciTech Connect

    Sexton, L.

    2015-10-14

    H Canyon and HB Line have a production goal of 1 MT per year of plutonium oxide feedstock for the MOX facility by FY17 (AFS-2 mission). In order to meet this goal, steps will need to be taken to improve processing efficiency. One concept for achieving this goal is to implement in-line process monitoring at key measurement points within the facilities. In-line monitoring during operations has the potential to increase throughput and efficiency while reducing costs associated with laboratory sample analysis. In the work reported here, we mapped the plutonium oxide process, identified key measurement points, investigated alternate technologies that could be used for in-line analysis, and initiated a throughput benefit analysis.

  12. Field validation of protocols developed to evaluate in-line mastitis detection systems.

    PubMed

    Kamphuis, C; Dela Rue, B T; Eastwood, C R

    2016-02-01

    This paper reports on a field validation of previously developed protocols for evaluating the performance of in-line mastitis-detection systems. The protocols outlined 2 requirements of these systems: (1) to detect cows with clinical mastitis (CM) promptly and accurately to enable timely and appropriate treatment and (2) to identify cows with high somatic cell count (SCC) to manage bulk milk SCC levels. Gold standard measures, evaluation tests, performance measures, and performance targets were proposed. The current study validated the protocols on commercial dairy farms with automated in-line mastitis-detection systems using both electrical conductivity (EC) and SCC sensor systems that both monitor at whole-udder level. The protocol for requirement 1 was applied on 3 commercial farms. For requirement 2, the protocol was applied on 6 farms; 3 of them had low bulk milk SCC (128×10(3) cells/mL) and were the same farms as used for field evaluation of requirement 1. Three farms with high bulk milk SCC (270×10(3) cells/mL) were additionally enrolled. The field evaluation methodology and results were presented at a workshop including representation from 7 international suppliers of in-line mastitis-detection systems. Feedback was sought on the acceptance of standardized performance evaluation protocols and recommended refinements to the protocols. Although the methodology for requirement 1 was relatively labor intensive and required organizational skills over an extended period, no major issues were encountered during the field validation of both protocols. The validation, thus, proved the protocols to be practical. Also, no changes to the data collection process were recommended by the technology supplier representatives. However, 4 recommendations were made to refine the protocols: inclusion of an additional analysis that ignores small (low-density) clot observations in the definition of CM, extension of the time window from 4 to 5 milkings for timely alerts for CM

  13. Holographic focal series: differences between inline and off-axis electron holography at atomic resolution

    NASA Astrophysics Data System (ADS)

    Niermann, Tore; Lehmann, Michael

    2016-05-01

    Electron holography methods allow phase information to be recovered from electron waves at atomic resolution. Focal-series reconstruction, an inline method, and off-axis holography are currently the most commonly employed techniques for this endeavor. By recording and reconstructing data from a holographic focal series of an atomically resolved GaAs crystal, we are able to reconstruct wave functions by means of both methods from the same measurement. Significant differences between these wave functions are found for low frequencies and in thicker specimen parts. Furthermore, in a rigorous treatment, we discuss how the recovered wave functions differ because of fundamental differences in the quantum mechanical measurement.

  14. In-line metrology setup for periodic nanostructures based on sub-wavelength diffraction

    NASA Astrophysics Data System (ADS)

    Kreuzer, Martin; Gomis Bresco, Jordi; Sledzinska, Marianna; Sotomayor Torres, Clivia M.

    2015-09-01

    The analysis of diffracted light from periodic structures is shown to be a versatile metrology technique applicable to inline metrology for periodic nanostructures. We show that 10 nm changes in periodic structures can be traced optically by means of sub-wavelength diffraction. Polymer gratings were fabricated by electron beam lithography. The gratings have a common periodicity of 6 μm, but different line width, ranging from 370 to 550 nm in 10 nm steps. A comparison between the resulting diffraction patterns shows marked differences in intensity which are used to sense nanometre scale deviations in periodic structures.

  15. An Inline Microstrip-to-Waveguide Transition Operating in the Full W-Band

    NASA Astrophysics Data System (ADS)

    Rebollo, Ainara; Gonzalo, Ramón; Ederra, Iñigo

    2015-08-01

    An inline microstrip-to-waveguide transition covering the full W-Band is presented in this article. The verification of the simulation results has been carried out by means of a back-to-back transition measurement. Experimental results show good return losses above 15 dB in the entire W-Band and also low insertion losses. Specifically, the measured insertion losses are 0.71 dB at the central frequency of W-Band, i.e., 92.5 GHz, and below 1.1 dB in the full W-band.

  16. Effects of Cycling Versus Running Training on Sprint and Endurance Capacity in Inline Speed Skating.

    PubMed

    Stangier, Carolin; Abel, Thomas; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K

    2016-03-01

    The purpose of this study was to compare the effects of running versus cycling training on sprint and endurance capacity in inline speed skating. Sixteen elite athletes (8 male, 8 female, 24 ± 8 yrs) were randomly assigned into 2 training groups performing either 2 session per week of treadmill running or ergometer cycling in addition to 3 skating specific sessions (technique, plyometrics, parkour) for 8 weeks. Training intensity was determined within non-specific (cycling or running) and effects on specific endurance capacity within a specific incremental exercise test. Before and after the intervention all athletes performed a specific (300m) and one non-specific (30s cycling or 200m running) all-out sprint test according to the group affiliation. To determine the accumulation of blood lactate (BLa) and glucose (BGL) 20 μl arterialized blood was drawn at rest, as well as in 1 min intervals for 10 min after the sprint test. The sport-specific peak oxygen uptake (VO2 peak) was significantly increased (+17%; p = 0.01) in both groups and highly correlated with the sprint performance (r = -0.71). BLa values decreased significantly (-18%, p = 0.02) after the specific sprint test from pre to post-testing without any group effect. However, BGL values only showed a significant decrease (-2%, p = 0.04) in the running group. The close relationship between aerobic capacity and sprint performance in inline speed skating highlights the positive effects of endurance training. Although both training programs were equally effective in improving endurance and sprint capacities, the metabolic results indicate a faster recovery after high intensity efforts for all athletes, as well as a higher reliance on the fat metabolism for athletes who trained in the running group. Key pointsIn addition to a highly developed aerobic performance inline speed skaters also require a highly trained anaerobic capacity to be effective in the sprint sections such as the mass start, tactical attacks

  17. Automatic laser welding and milling with in situ inline coherent imaging.

    PubMed

    Webster, P J L; Wright, L G; Ji, Y; Galbraith, C M; Kinross, A W; Van Vlack, C; Fraser, J M

    2014-11-01

    Although new affordable high-power laser technologies enable many processing applications in science and industry, depth control remains a serious technical challenge. In this Letter we show that inline coherent imaging (ICI), with line rates up to 312 kHz and microsecond-duration capture times, is capable of directly measuring laser penetration depth, in a process as violent as kW-class keyhole welding. We exploit ICI's high speed, high dynamic range, and robustness to interference from other optical sources to achieve automatic, adaptive control of laser welding, as well as ablation, achieving 3D micron-scale sculpting in vastly different heterogeneous biological materials. PMID:25361318

  18. Effects of Cycling Versus Running Training on Sprint and Endurance Capacity in Inline Speed Skating

    PubMed Central

    Stangier, Carolin; Abel, Thomas; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K.

    2016-01-01

    The purpose of this study was to compare the effects of running versus cycling training on sprint and endurance capacity in inline speed skating. Sixteen elite athletes (8 male, 8 female, 24 ± 8 yrs) were randomly assigned into 2 training groups performing either 2 session per week of treadmill running or ergometer cycling in addition to 3 skating specific sessions (technique, plyometrics, parkour) for 8 weeks. Training intensity was determined within non-specific (cycling or running) and effects on specific endurance capacity within a specific incremental exercise test. Before and after the intervention all athletes performed a specific (300m) and one non-specific (30s cycling or 200m running) all-out sprint test according to the group affiliation. To determine the accumulation of blood lactate (BLa) and glucose (BGL) 20 μl arterialized blood was drawn at rest, as well as in 1 min intervals for 10 min after the sprint test. The sport-specific peak oxygen uptake (VO2 peak) was significantly increased (+17%; p = 0.01) in both groups and highly correlated with the sprint performance (r = -0.71). BLa values decreased significantly (-18%, p = 0.02) after the specific sprint test from pre to post-testing without any group effect. However, BGL values only showed a significant decrease (-2%, p = 0.04) in the running group. The close relationship between aerobic capacity and sprint performance in inline speed skating highlights the positive effects of endurance training. Although both training programs were equally effective in improving endurance and sprint capacities, the metabolic results indicate a faster recovery after high intensity efforts for all athletes, as well as a higher reliance on the fat metabolism for athletes who trained in the running group. Key points In addition to a highly developed aerobic performance inline speed skaters also require a highly trained anaerobic capacity to be effective in the sprint sections such as the mass start, tactical attacks

  19. Twin image removal in digital in-line holography based on iterative inter-projections

    NASA Astrophysics Data System (ADS)

    Chen, Bing Kuan; Chen, Tai-Yu; Hung, Shau Gang; Huang, Sheng-Lung; Lin, Jiunn-Yuan

    2016-06-01

    A simple and efficient phase retrieval method based on the iterative inter-projections of the recorded Fourier modulus between two effective holographic planes is developed to eliminate the twin image in digital in-line holography. The proposed algorithm converges stably in phase extraction procedures without requiring any prior knowledge or sophisticated support of the object and is applicable to lensless Gabor and Fourier holography as well as holographic microscopy with imaging lenses. Numerical and experimental results suggest that the spatial resolution enhancement on the reconstructed image can be achieved with this technique due to the capability of recovering the diffraction phases of low-intensity signals.

  20. Production of higher quality bio-oils by in-line esterification of pyrolysis vapor

    DOEpatents

    Hilten, Roger Norris; Das, Keshav; Kastner, James R; Bibens, Brian P

    2014-12-02

    The disclosure encompasses in-line reactive condensation processes via vapor phase esterification of bio-oil to decease reactive species concentration and water content in the oily phase of a two-phase oil, thereby increasing storage stability and heating value. Esterification of the bio-oil vapor occurs via the vapor phase contact and subsequent reaction of organic acids with ethanol during condensation results in the production of water and esters. The pyrolysis oil product can have an increased ester content and an increased stability when compared to a condensed pyrolysis oil product not treated with an atomized alcohol.

  1. Layer-separated MoS2 bearing reduced graphene oxide formed by an in situ intercalation-cum-anchoring route mediated by Co(OH)2 as a Pt-free electrocatalyst for oxygen reduction

    NASA Astrophysics Data System (ADS)

    Illathvalappil, Rajith; Unni, Sreekuttan M.; Kurungot, Sreekumar

    2015-10-01

    A significant improvement in the electrochemical oxygen reduction reaction (ORR) activity of molybdenum sulphide (MoS2) could be accomplished by its layer separated dispersion on graphene mediated by cobalt hydroxide (Co(OH)2) through a hydrothermal process (Co(OH)2-MoS2/rGO). The activity makeover in this case is found to be originated from a controlled interplay of the favourable modulations achieved in terms of electrical conductivity, more exposure of the edge planes of MoS2 and a promotional role played by the coexistence of Co(OH)2 in the proximity of MoS2. Co(OH)2-MoS2/rGO displays an oxygen reduction onset potential of 0.855 V and a half wave potential (E1/2) of 0.731 V vs. RHE in 0.1 M KOH solution, which are much higher than those of the corresponding values (0.708 and 0.349 V, respectively) displayed by the as synthesized pristine MoS2 (P-MoS2) under identical experimental conditions. The Tafel slope corresponding to oxygen reduction for Co(OH)2-MoS2/rGO is estimated to be 63 mV dec-1 compared to 68 mV dec-1 displayed by the state-of-the-art Pt/C catalyst. The estimated number of electrons transferred during oxygen reduction for Co(OH)2-MoS2/rGO is in the range of 3.2-3.6 in the potential range of 0.77 V to 0.07 V, which again stands out as valid evidence on the much favourable mode of oxygen reduction accomplished by the system compared to its pristine counterpart. Overall, the present study, thus, demonstrates a viable strategy of tackling the inherent limitations, such as low electrical conductivity and limited access to the active sites, faced by the layered structures like MoS2 to position them among the group of potential Pt-free electrocatalysts for oxygen reduction.A significant improvement in the electrochemical oxygen reduction reaction (ORR) activity of molybdenum sulphide (MoS2) could be accomplished by its layer separated dispersion on graphene mediated by cobalt hydroxide (Co(OH)2) through a hydrothermal process (Co(OH)2-MoS2/rGO). The

  2. SEPARATION PROCESS

    DOEpatents

    Stoughton, R.W.

    1961-10-24

    A process for separating tetravalent plutonium from aqueous solutions and from niobium and zirconium by precipitation on lanthanum oxalate is described. The oxalate ions of the precipitate may be decomposed by heating in the presence of an oxidizing agent, forming a plutonium compound readily soluble in acid. (AEC)

  3. Separation Group.

    ERIC Educational Resources Information Center

    Addington, Jean

    1992-01-01

    Describes eight-week short-term group designed to help separated or divorced men and women move through related adjustment phase in focused group setting. Discusses constructs that form the foundations of this short-term psychoeducational and support group and presents brief overview of psychological difficulties that occur as result of marital…

  4. Improved high-performance liquid chromatography analysis of 32P-postlabeled 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine-DNA adducts using in-line precolumn purification.

    PubMed

    Mauthe, R J; Marsch, G A; Turteltaub, K W

    1996-04-26

    An improved HPLC-based 32P-postlabeling assay has been developed for the analysis of DNA modified with the food carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Postlabeled samples are loaded onto a C18 precolumn and adducted bases are retained while excess radioactivity and unmodified DNA bases are eluted directly to waste through a switching valve. The use of this HPLC in-line precolumn purification (HIPP) technique allows entire postlabeled samples to be analyzed without prior removal of inorganic phosphate and unmodified DNA bases. The method has a sample to sample precision of 15% and accuracy of 20%, at adduct levels of 2 adducts/10(7) bases and shows a linear relationship between signal and adduction levels from 1 adduct per 10(4) to approximately 2 +/- 1 adducts per 10(9) bases. Individual postlabeled DNA samples can be analyzed by HPLC in less than 1 h, allowing high throughput. The use of calf-thymus DNA (CT-DNA), highly modified with PhIP, or DNA isolated from mice chronically fed a PhIP-modified diet shows two major PhIP-DNA adduct peaks and three additional minor adduct peaks when labeled under ATP-limiting conditions. Isolation of the HPLC purified peaks and analysis by thin layer chromatography (TLC) matches the five HPLC peaks to the spots typically seen by TLC, including N-(deoxyguanosin-8-yl)-2-amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (dG-C8-PhIP). Variations in digestion techniques indicate a potential resistance of the PhIP-DNA adducts to the standard enzymatic digestion methods. Attempts at adduct intensification by solid phase extraction, nuclease P1 enrichment or 1-butanol extraction decreased PhIP-DNA adduct peaks and introduced a large early eluting peak. Removal of the 3'-phosphate with nuclease P1 following the kinase labeling reaction simplifies the HPLC profile to one major peak (dG-C8-PhIP monophosphate) with several minor peaks. In addition to the high resolution provided by HPLC separation of the Ph

  5. Thin Film CdS/CdTe Solar Cells Produced in a CSS In-Line System

    SciTech Connect

    Cruz, L. R.; Pinheiro, W. A.; Ferreira, C. L.; Duenow, J. N.; Dhere, R. G.

    2011-01-01

    This work shows results for CdS/CdTe photovoltaic cells grown in a homemade in-line close-spaced sublimation equipment. In this system, most of the steps of cell fabrication were carried out continuously, using dry processing, without breaking vacuum. The efficiency values ranged from 3.5 to 7%. These cells were compared with unfinished devices prepared in the in-line system and finished (heat treatment and contact processing) at NREL. The results suggested that some steps in the cell fabrication should be optimized.

  6. Highly sensitive chiral analysis of amino acids by in-line single drop microextraction and capillary electrophoresis with laser-induced fluorescence detection.

    PubMed

    Liang, Guodong; Choi, Kihwan; Badjah Hadj Ahmed, Ahmed Yacine; ALOthman, Zeid A; Chung, Doo Soo

    2010-09-10

    A highly sensitive method for chiral analysis of amino acids by in-line single drop microextraction (SDME) and chiral capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection was developed. In SDME, a drop of a basic aqueous acceptor phase covered with a thin organic layer was formed at the tip of a capillary by simple combination of sample-handling sequences of a CE apparatus. Then fluorescein isothiocyanate (FITC)-derivatized amino acids in an acidic donor solution were enriched into the drop through the organic layer. The enriched enantiomers were then resolved using a dual chiral selector of β-cyclodextrin (β-CD) and sodium taurodeoxycholate (STC). Here, in addition to serving as a labeling reagent providing high fluorescence signal, hydrophobic FITC was primarily used as a modifier aiding the extraction of zwitterionic amino acids by blocking the amino groups and increasing the hydrophobicity, yielding 220 times increase in extraction efficiency. Several hundred-fold enrichments were achieved with 10 min SDME, yielding LODs of 30-60 pM and enabling direct analysis of d-AAs in a 99% enantiomeric excess mixture. In view of no additional modification of the existing commercial CE instrument, this method without stirring can be easily realized using known operations. When a microstirrer was customized to the CE instrument several thousand-fold enrichments could be obtained with LODs in the low picomolar range of 1-3 pM. PMID:20850587

  7. Organic Separation Test Results

    SciTech Connect

    Russell, Renee L.; Rinehart, Donald E.; Peterson, Reid A.

    2014-09-22

    Separable organics have been defined as “those organic compounds of very limited solubility in the bulk waste and that can form a separate liquid phase or layer” (Smalley and Nguyen 2013), and result from three main solvent extraction processes: U Plant Uranium Recovery Process, B Plant Waste Fractionation Process, and Plutonium Uranium Extraction (PUREX) Process. The primary organic solvents associated with tank solids are TBP, D2EHPA, and NPH. There is concern that, while this organic material is bound to the sludge particles as it is stored in the tanks, waste feed delivery activities, specifically transfer pump and mixer pump operations, could cause the organics to form a separated layer in the tank farms feed tank. Therefore, Washington River Protection Solutions (WRPS) is experimentally evaluating the potential of organic solvents separating from the tank solids (sludge) during waste feed delivery activities, specifically the waste mixing and transfer processes. Given the Hanford Tank Waste Treatment and Immobilization Plant (WTP) waste acceptance criteria per the Waste Feed Acceptance Criteria document (24590-WTP-RPT-MGT-11-014) that there is to be “no visible layer” of separable organics in the waste feed, this would result in the batch being unacceptable to transfer to WTP. This study is of particular importance to WRPS because of these WTP requirements.

  8. Gas separating

    DOEpatents

    Gollan, Arye

    1988-01-01

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing.

  9. Gas separating

    DOEpatents

    Gollan, Arye Z.

    1990-12-25

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing.

  10. Separation system

    DOEpatents

    Rubin, Leslie S.

    1986-01-01

    A separation system for dewatering radioactive waste materials includes a disposal container, drive structure for receiving the container, and means for releasably attaching the container to the drive structure. Separation structure disposed in the container adjacent the inner surface of the side wall structure retains solids while allowing passage of liquids. Inlet port structure in the container top wall is normally closed by first valve structure that is centrifugally actuated to open the inlet port and discharge port structure at the container periphery receives liquid that passes through the separation structure and is normally closed by second valve structure that is centrifugally actuated to open the discharge ports. The container also includes coupling structure for releasable engagement with the centrifugal drive structure. Centrifugal force produced when the container is driven in rotation by the drive structure opens the valve structures, and radioactive waste material introduced into the container through the open inlet port is dewatered, and the waste is compacted. The ports are automatically closed by the valves when the container drum is not subjected to centrifugal force such that containment effectiveness is enhanced and exposure of personnel to radioactive materials is minimized.

  11. Component separations.

    PubMed

    Heller, Lior; McNichols, Colton H; Ramirez, Oscar M

    2012-02-01

    Component separation is a technique used to provide adequate coverage for midline abdominal wall defects such as a large ventral hernia. This surgical technique is based on subcutaneous lateral dissection, fasciotomy lateral to the rectus abdominis muscle, and dissection on the plane between external and internal oblique muscles with medial advancement of the block that includes the rectus muscle and its fascia. This release allows for medial advancement of the fascia and closure of up to 20-cm wide defects in the midline area. Since its original description, components separation technique underwent multiple modifications with the ultimate goal to decrease the morbidity associated with the traditional procedure. The extensive subcutaneous lateral dissection had been associated with ischemia of the midline skin edges, wound dehiscence, infection, and seroma. Although the current trend is to proceed with minimally invasive component separation and to reinforce the fascia with mesh, the basic principles of the techniques as described by Ramirez et al in 1990 have not changed over the years. Surgeons who deal with the management of abdominal wall defects are highly encouraged to include this technique in their collection of treatment options. PMID:23372455

  12. Enhancing flexible fiber filter (3FM) performance using in-line coagulation.

    PubMed

    Lee, J J; Jeong, M K; Im, J H; BenAim, R; Lee, S H; Oh, J E; Woo, H J; Kim, C W

    2006-01-01

    A new packing for deep bed filtration using Flexible Fibers has been proposed and developed on a very large scale for tertiary treatment of wastewater. The purpose of this study is to check the possibility of using this technology for the production of drinking water from surface water. In this study, the feasibility of the fiber filter application on water treatment was examined and the removal efficiency of fiber filter was improved using an in-line coagulant injection method. The experiments were carried out at pilot scale. The filter was packed with bundles of polyamide fibers with a bed porosity of 93%. Nak-dong River was used as the filter influent water and alum, PSOM, and PAC were used as the coagulants. The coagulants were injected by the in-line injection method. Small dosages (1-5 mg/L) of the polymeric coagulants (PSOM and PAC) showed an increase of removal efficiency compared to the operation without coagulants. Specifically, 1 mg/L of PAC showed the longest filtration time. Considering filtration time, filtrate quality, and filtered volume, the filtration velocity of 120 m/hr was chosen as an optimum value. For long-term operations, the effluent quality was 0.4 NTU and the removal efficiency was stable for the given optimum conditions. PMID:16752765

  13. Pistol ribozyme adopts a pseudoknot fold facilitating site-specific in-line cleavage.

    PubMed

    Ren, Aiming; Vušurović, Nikola; Gebetsberger, Jennifer; Gao, Pu; Juen, Michael; Kreutz, Christoph; Micura, Ronald; Patel, Dinshaw J

    2016-09-01

    The field of small self-cleaving nucleolytic ribozymes has been invigorated by the recent discovery of the twister, twister-sister, pistol and hatchet ribozymes. We report the crystal structure of a pistol ribozyme termed env25, which adopts a compact tertiary architecture stabilized by an embedded pseudoknot fold. The G-U cleavage site adopts a splayed-apart conformation with in-line alignment of the modeled 2'-O of G for attack on the adjacent to-be-cleaved P-O5' bond. Highly conserved residues G40 (N1 position) and A32 (N3 and 2'-OH positions) are aligned to act as a general base and a general acid, respectively, to accelerate cleavage chemistry, with their roles confirmed by cleavage assays on variants, and an increased pKa of 4.7 for A32. Our structure of the pistol ribozyme defined how the overall and local topologies dictate the in-line alignment at the G-U cleavage site, with cleavage assays on variants revealing key residues that participate in acid-base-catalyzed cleavage chemistry. PMID:27398999

  14. In-line microfluidic integration of photonic crystal fibres as a highly sensitive refractometer.

    PubMed

    Wu, Chuang; Tse, Ming-Leung Vincent; Liu, Zhengyong; Guan, Bai-Ou; Zhang, A Ping; Lu, Chao; Tam, Hwa-Yaw

    2014-11-01

    Photonic crystal fibres appear to be an ideal platform for the realisation of novel optofluidic devices and sensors due to their waveguide nature and microstructured architecture. In this paper, we present the fabrication and characterisation of an in-line photonic crystal fibre microfluidic refractometer enabled by a C-shaped fibre. The C-shaped fibre spliced in-between the photonic crystal fibre and the single-mode fibre allows simultaneous in-line optical signal delivery and analyte fluid feeding. Through an arc discharge pre-treatment technique, we successfully achieve selective exploitation of only the central two channels of the photonic crystal fibre for microfluidic sensing. After constructing a Sagnac interferometer, a highly sensitive refractometer with a sensitivity of 8699 nm per RIU was achieved experimentally; this agrees very well with the theoretical value of 8675 nm per RIU. As a demonstration for label-free optical sensing application, the refractometer was used to measure the concentration of NaCl solution with a sensitivity of 15.08 nm/(1 wt%) and a detection limit of 2.3 × 10(-3) wt% (23 ppm). PMID:25142213

  15. Inline state of health estimation of lithium-ion batteries using state of charge calculation

    NASA Astrophysics Data System (ADS)

    Sepasi, Saeed; Ghorbani, Reza; Liaw, Bor Yann

    2015-12-01

    The determination of state-of-health (SOH) and state-of-charge (SOC) is challenging and remains as an active research area in academia and industry due to its importance for Li-ion battery applications. The estimation process poses more challenges after substantial battery aging. This paper presents an inline SOH and SOC estimation method for Li-ion battery packs, specifically for those based on LiFePO4 chemistry. This new hybridized SOC and SOH estimator can be used for battery packs. Inline estimated model parameters were used in a compounded SOC + SOH estimator consisting of the SOC calculation based on coulomb counting method as an expedient approach and an SOH observer using an extended Kalman filter (EKF) technique for calibrating the estimates from the coulomb counting method. The algorithm's low SOC and SOH estimation error, fast response time, and less-demanding computational requirement make it practical for on-board estimations. The simulation and experimental results, along with the test bed structure, are presented to validate the proposed methodology on a single cell and a 3S1P LiFePO4 battery pack.

  16. Estimation of parameters for evaluating subsurface microcracks in glass with in-line digital holographic microscopy.

    PubMed

    Wu, Xiupin; Gao, Wanrong; He, Yong

    2016-01-20

    In this work, a new method for imaging subsurface damage (SSD) is proposed, which is, to the best of our knowledge, the first application of the in-line digital holographic microscopy (IDHM) to the reconstruction of the subsurface damage in glass. By combination of the in-line arrangement and an objective lens to image the hologram on the CCD surface, the method is characterized by its high resolution in both the lateral and depth directions. Then the three-dimensional reconstruction of the microcracks within the glass was realized by numerically focusing en-face images at different depths, and the sizes of SSD along the transversal and depth directions were estimated. Based on the experimental results, the cracks can be divided into two categories: one is that the cracks begin from the surface of optical elements, the other is totally within the components. To indicate the propagation or development trajectory of the cracks and predict the magnitude of the laser-induced damage threshold, the relative intensity distributions of the light scattered by the cracks compared with the ones without cracks were also reconstructed. In this case all the required parameters for evaluating SSD are obtained with our IDHM system, so that the SSD produced in the manufacturing process can be reduced or removed more easily to optimize the performance of the optical component and extend its lifetime. These results provide the guidance for the optical system design of precision measurements. PMID:26835955

  17. Raman Spectroscopy for In-Line Water Quality Monitoring — Instrumentation and Potential

    PubMed Central

    Li, Zhiyun; Deen, M. Jamal; Kumar, Shiva; Selvaganapathy, P. Ravi

    2014-01-01

    Worldwide, the access to safe drinking water is a huge problem. In fact, the number of persons without safe drinking water is increasing, even though it is an essential ingredient for human health and development. The enormity of the problem also makes it a critical environmental and public health issue. Therefore, there is a critical need for easy-to-use, compact and sensitive techniques for water quality monitoring. Raman spectroscopy has been a very powerful technique to characterize chemical composition and has been applied to many areas, including chemistry, food, material science or pharmaceuticals. The development of advanced Raman techniques and improvements in instrumentation, has significantly improved the performance of modern Raman spectrometers so that it can now be used for detection of low concentrations of chemicals such as in-line monitoring of chemical and pharmaceutical contaminants in water. This paper briefly introduces the fundamentals of Raman spectroscopy, reviews the development of Raman instrumentations and discusses advanced and potential Raman techniques for in-line water quality monitoring. PMID:25230309

  18. Gas Research Institute's research and development program on in-line inspection of natural gas pipelines

    NASA Astrophysics Data System (ADS)

    Haines, Harvey H.; Bubenik, Tom A.; Nestleroth, J. Bruce

    1995-05-01

    The Gas Research Institute (GRI) has been supporting a comprehensive research and development program on in-line inspection techniques for natural gas transmission pipelines. This program contains assessments of state-of-the-art nondestructive evaluation methods, improvements in current approaches, and developments of advanced inspection technologies. The elements of the GRI Nondestructive Evaluation Program range from laboratory evaluations of the capabilities of inspection technologies to large-scale measurements in simulated pipeline settings. Each level of research stresses a quantification of both the limits of detection and the accuracy of characterization of pipeline imperfections that are found by in- line inspection tools. The overall goal of GRI's Nondestructive Evaluation Program is to develop and improve technologies that will help gas pipeline companies maintain the physical integrity of their transmission systems, prevent pipeline shutdowns, and reduce maintenance costs. This paper summarizes the results of the GRI program to date in relationship to their direct application to in-line inspection of gas transmission pipelines. The program consists of three main elements: facilities development, research on current inspection technologies, and research on future inspection technologies. The facilities development is centered around the Pipeline Simulation Facility; the research on current inspection technologies is aimed at improving magnetic flux leakage analyses; and the research on future inspection technologies is centered on stress-corrosion crack detection and characterization.

  19. Automated Aflatoxin Analysis Using Inline Reusable Immunoaffinity Column Cleanup and LC-Fluorescence Detection.

    PubMed

    Rhemrev, Ria; Pazdanska, Monika; Marley, Elaine; Biselli, Scarlett; Staiger, Simone

    2015-01-01

    A novel reusable immunoaffinity cartridge containing monoclonal antibodies to aflatoxins coupled to a pressure resistant polymer has been developed. The cartridge is used in conjunction with a handling system inline to LC with fluorescence detection to provide fully automated aflatoxin analysis for routine monitoring of a variety of food matrixes. The handling system selects an immunoaffinity cartridge from a tray and automatically applies the sample extract. The cartridge is washed, then aflatoxins B1, B2, G1, and G2 are eluted and transferred inline to the LC system for quantitative analysis using fluorescence detection with postcolumn derivatization using a KOBRA® cell. Each immunoaffinity cartridge can be used up to 15 times without loss in performance, offering increased sample throughput and reduced costs compared to conventional manual sample preparation and cleanup. The system was validated in two independent laboratories using samples of peanuts and maize spiked at 2, 8, and 40 μg/kg total aflatoxins, and paprika, nutmeg, and dried figs spiked at 5, 20, and 100 μg/kg total aflatoxins. Recoveries exceeded 80% for both aflatoxin B1 and total aflatoxins. The between-day repeatability ranged from 2.1 to 9.6% for aflatoxin B1 for the six levels and five matrixes. Satisfactory Z-scores were obtained with this automated system when used for participation in proficiency testing (FAPAS®) for samples of chilli powder and hazelnut paste containing aflatoxins. PMID:26651571

  20. HELIOS-CR A 1-D radiation-magnetohydrodynamics code with inline atomic kinetics modeling

    NASA Astrophysics Data System (ADS)

    Macfarlane, J. J.; Golovkin, I. E.; Woodruff, P. R.

    2006-05-01

    HELIOS-CR is a user-oriented 1D radiation-magnetohydrodynamics code to simulate the dynamic evolution of laser-produced plasmas and z-pinch plasmas. It includes an in-line collisional-radiative (CR) model for computing non-LTE atomic level populations at each time step of the hydrodynamics simulation. HELIOS-CR has been designed for ease of use, and is well-suited for experimentalists, as well as graduate and undergraduate student researchers. The energy equations employed include models for laser energy deposition, radiation from external sources, and high-current discharges. Radiative transport can be calculated using either a multi-frequency flux-limited diffusion model, or a multi-frequency, multi-angle short characteristics model. HELIOS-CR supports the use of SESAME equation of state (EOS) tables, PROPACEOS EOS/multi-group opacity data tables, and non-LTE plasma properties computed using the inline CR modeling. Time-, space-, and frequency-dependent results from HELIOS-CR calculations are readily displayed with the HydroPLOT graphics tool. In addition, the results of HELIOS simulations can be post-processed using the SPECT3D Imaging and Spectral Analysis Suite to generate images and spectra that can be directly compared with experimental measurements. The HELIOS-CR package runs on Windows, Linux, and Mac OSX platforms, and includes online documentation. We will discuss the major features of HELIOS-CR, and present example results from simulations.

  1. Hydrodynamic Forces On A Cylinder Vibrating Transversely And In-Line To A Steady Stream

    NASA Astrophysics Data System (ADS)

    Triantafyllou, George; Kaiktsis, Lambros; Peppa, Sofia

    2008-11-01

    We present computational results on the flow structure and forces in flow past a circular cylinder oscillating transversely and in-line to a uniform stream at Reynolds number 400. Three values of the transverse vibration frequency are implemented, corresponding to 1.0, 0.9 and 1.1 times the natural frequency of the Karman vortex street. The in-line vibration occurs at twice the frequency of the transverse oscillation. The cylinder thus follows an ``eight''-like trajectory, emulating the trajectory of a free vortex-induced vibration. We find that the results of the simulation are greatly influenced by the direction in which the ``eight'' figure is traversed. We distinguish between a ``counterclockwise'' mode (if the upper part of the trajectory is traversed counterclockwise), and a ``clockwise'' mode (if the upper part of the trajectory is traversed clockwise). We find that the counterclockwise mode results in larger fluid forces than the clockwise mode for the same amplitude of oscillation. The power transfer from the fluid to the cylinder remains positive for the counterclockwise mode at higher values of the amplitude-over-diameter-ratio than it does either for the clockwise mode or for a transversely only vibrating cylinder.

  2. Model and analysis of a cylindrical in-line hydraulic suppressor with a solid compressible liner

    NASA Astrophysics Data System (ADS)

    Marek, K. A.; Earnhart, N. E.; Cunefare, K. A.

    2014-12-01

    An in-line hydraulic noise suppressor with a lossy, compressible liner made of foamed polyurethane liner is introduced which is intended to provide an alternative to current in-line silencing devices using compressed nitrogen gas volumes. The liner is engineered to be compressible at elevated pressures, such that it can provide effective noise abatement for practical hydraulic systems. In support of such work, a multimodal model is developed to characterize the device and the liner material. Because the hydraulic system is pressurized after insertion of the liner, the model must address liner compression and the corresponding small gaps introduced in the expansion volume; additionally, both compression and shear wave propagation must be considered in the liner. Several mode matching solutions are investigated, and a pseudoinverse mode matching method is found to provide good convergence characteristics. The multimodal model is validated against a finite element model, and also used in an optimization algorithm to estimate the material properties of a prototype liner using experimental transmission loss data. Experimental results show broadband transmission loss performance at 2.8 MPa system pressure; transmission loss decreases with increasing system pressure, and data at 4.1 MPa system pressure produces about 4 dB less transmission loss than a similarly sized commercial device. The multimodal model with estimated material properties at 2.8 MPa achieves a root mean squared error of 1.7 dB or less for two different length devices over a frequency range of 50-2000 Hz.

  3. Terahertz in-line digital holography of human hepatocellular carcinoma tissue

    NASA Astrophysics Data System (ADS)

    Rong, Lu; Latychevskaia, Tatiana; Chen, Chunhai; Wang, Dayong; Yu, Zhengping; Zhou, Xun; Li, Zeyu; Huang, Haochong; Wang, Yunxin; Zhou, Zhou

    2015-02-01

    Terahertz waves provide a better contrast in imaging soft biomedical tissues than X-rays, and unlike X-rays, they cause no ionisation damage, making them a good option for biomedical imaging. Terahertz absorption imaging has conventionally been used for cancer diagnosis. However, the absorption properties of a cancerous sample are influenced by two opposing factors: an increase in absorption due to a higher degree of hydration and a decrease in absorption due to structural changes. It is therefore difficult to diagnose cancer from an absorption image. Phase imaging can thus be critical for diagnostics. We demonstrate imaging of the absorption and phase-shift distributions of 3.2 mm × 2.3 mm × 30-μm-thick human hepatocellular carcinoma tissue by continuous-wave terahertz digital in-line holography. The acquisition time of a few seconds for a single in-line hologram is much shorter than that of other terahertz diagnostic techniques, and future detectors will allow acquisition of meaningful holograms without sample dehydration. The resolution of the reconstructions was enhanced by sub-pixel shifting and extrapolation. Another advantage of this technique is its relaxed minimal sample size limitation. The fibrosis indicated in the phase distribution demonstrates the potential of terahertz holographic imaging to obtain a more objective, early diagnosis of cancer.

  4. Terahertz in-line digital holography of human hepatocellular carcinoma tissue

    PubMed Central

    Rong, Lu; Latychevskaia, Tatiana; Chen, Chunhai; Wang, Dayong; Yu, Zhengping; Zhou, Xun; Li, Zeyu; Huang, Haochong; Wang, Yunxin; Zhou, Zhou

    2015-01-01

    Terahertz waves provide a better contrast in imaging soft biomedical tissues than X-rays, and unlike X-rays, they cause no ionisation damage, making them a good option for biomedical imaging. Terahertz absorption imaging has conventionally been used for cancer diagnosis. However, the absorption properties of a cancerous sample are influenced by two opposing factors: an increase in absorption due to a higher degree of hydration and a decrease in absorption due to structural changes. It is therefore difficult to diagnose cancer from an absorption image. Phase imaging can thus be critical for diagnostics. We demonstrate imaging of the absorption and phase-shift distributions of 3.2 mm × 2.3 mm × 30-μm-thick human hepatocellular carcinoma tissue by continuous-wave terahertz digital in-line holography. The acquisition time of a few seconds for a single in-line hologram is much shorter than that of other terahertz diagnostic techniques, and future detectors will allow acquisition of meaningful holograms without sample dehydration. The resolution of the reconstructions was enhanced by sub-pixel shifting and extrapolation. Another advantage of this technique is its relaxed minimal sample size limitation. The fibrosis indicated in the phase distribution demonstrates the potential of terahertz holographic imaging to obtain a more objective, early diagnosis of cancer. PMID:25676705

  5. Inline monitoring and a PAT strategy for pharmaceutical hot melt extrusion.

    PubMed

    Wahl, Patrick R; Treffer, Daniel; Mohr, Stefan; Roblegg, Eva; Koscher, Gerold; Khinast, Johannes G

    2013-10-15

    Implementation of continuous manufacturing in the pharmaceutical industry requires tight process control. This study focuses on a PAT strategy for hot melt extrusion of vegetable calcium stearate (CaSt) as matrix carrier and paracetamol as active pharmaceutical ingredient (API). The extrusion was monitored using in-line near-infrared (NIR) spectroscopy. A NIR probe was located in the section between the extrusion screws and the die, using a novel design of the die channel. A chemometric model was developed based on premixes at defined concentrations and was implemented in SIPAT for real time API concentration monitoring. Subsequently, step experiments were performed for different API concentrations, screw speeds and screw designs. The predicted API concentration was in good agreement with the pre-set concentrations. The transition from one API plateau to another was a smooth curve due to the mixing behaviour of the extruder. The accuracy of the model was confirmed via offline HPLC analysis. The screw design was determined as the main influential factor on content uniformity (CU). Additionally the influence of multiple feeders had a significant impact on CU. The results demonstrate that in-line NIR measurements is a powerful tool for process development (e.g., mixing characterization), monitoring and further control strategies. PMID:23911343

  6. Cardiorespiratory demands during an inline speed skating marathon race: a case report.

    PubMed

    Stangier, Carolin; Abel, Thomas; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K

    2016-09-01

    This study was designed to investigate the intensity profile during an inline speed skating marathon road race. A highly-trained male athlete (20 y, 73.4 kg, 178 cm, V̇O2 peak: 60.8 mL·kg-1·min-1) participated in a marathon road race. Oxygen uptake (V̇O2), respiratory exchange ratio (RER), heart rate (HR) and speed were measured using a portable gas analysis system with a HR monitor and GPS-Sensor integrated. The athlete´s peak V̇O2, HR and speed at ventilatory thresholds were assessed during an incremental field test (22 km·h-1, increase 2 km·h-1 every 5 min) one week before the race. During the race, the absolute time spent in the "easy intensity zone" (V̇O2 below VT1) was 1 min, 49 min "moderate intensity zone" (V̇O2 between VT1 and VT2), and 26 min in the "hard intensity zone" (V̇O2 above VT2). The average HR was 171±6 bpm, corresponding to 95% of the maximum. This study shows that inline speed skating road races over a marathon are conducted at moderate to high V̇O2 and heart rate levels. The physiological racing pattern is very intermittent, requiring both a high level of aerobic and anaerobic capacity. PMID:26745782

  7. Simultaneous Multiple-Location Separation Control

    NASA Technical Reports Server (NTRS)

    Greenblatt, David (Inventor)

    2009-01-01

    A method of controlling a shear layer for a fluid dynamic body introduces first periodic disturbances into the fluid medium at a first flow separation location. Simultaneously, second periodic disturbances are introduced into the fluid medium at a second flow separation location. A phase difference between the first and second periodic disturbances is adjusted to control flow separation of the shear layer as the fluid medium moves over the fluid dynamic body.

  8. In-Line Crack and Stress Detection in Silicon Solar Cells Using Resonance Ultrasonic Vibrations

    SciTech Connect

    Ostapenko, Sergei

    2013-04-03

    Statement of Problem and Objectives. Wafer breakage in automated solar cell production lines is identified as a major technical problem and a barrier for further cost reduction of silicon solar module manufacturing. To the best of our knowledge, there are no commercial systems addressing critical needs for in-line inspection of the mechanical quality of solar wafers and cells. The principal objective of the SBIR program is to validate through experiments and computer modeling the applicability of the Resonance Ultrasonic Vibrations system, which ultimately can be used as a real-time in-line manufacturing quality control tool for fast detection of mechanically unstable silicon solar cells caused by cracks. The specific objective of Phase II is to move the technology of in-line crack detection from the laboratory level to commercial demonstration through development of a system prototype. The fragility of silicon wafers possessing low mechanical strength is attributed to peripheral and bulk millimeter-length cracks. The research program is based on feasibility results obtained during Phase I, which established that: (i) the Resonance Ultrasonic Vibrations method is applicable to as-cut, processed wafers and finished cells; (ii) the method sensitivity depends on the specific processing step; it is highest in as-cut wafers and lowest in wafers with metallization pattern and grid contacts; (iii) the system is capable of matching the 2.0 seconds per wafer throughput rate of state-of-art solar cell production lines; (iv) finite element modeling provides vibration mode analysis along with peak shift versus crack length and crack location dependence; (v) a high 91% crack rejection rate was confirmed through experimentation and statistical analysis. The Phase II project has the following specific tasks: (i) specify optimal configurations of the in-line system's component hardware and software; (ii) develop and justify a system prototype that meets major specifications for an

  9. Hyphenation of gas-diffusion separation and ion chromatography. Part 1: determination of free sulfite in wines.

    PubMed

    Fäldt, S; Karlberg, B; Frenzel, W

    2001-10-01

    The hyphenation of gas-diffusion separation and ion chromatography (IC) is described as a convenient, reliable, robust, and economic method for in-line sample pre-treatment. The high selectivity associated with this method permits direct analysis of samples containing microparticulates, colloidal matter, and/or high molecular weight compounds. The determination of sulfite serves as a first example of its application. The method is based on the diffusional separation of SO2 following in-line oxidation with hydrogen peroxide to sulfate and final determination of the sulfate formed using IC. The influence of operational parameters has been thoroughly investigated and gas-diffusion cells of different geometries compared with respect to the gas-transfer rates obtained. Application to the analysis of wines demonstrates the utility of the method. PMID:11760049

  10. Gas separating

    DOEpatents

    Gollan, A.Z.

    1990-12-25

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  11. Artwork Separation

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Under a grant from California Institute of Technology, Jet Propulsion Laboratory (JPL) and LACMA (Los Angeles County Museum of Art) used image enhancement techniques to separate x-ray images of paintings when one had been painted on top of another. The technique is derived from computer processing of spacecraft-acquired imagery, and will allow earlier paintings, some of which have been covered for centuries, to be evaluated. JPL developed the program for "subtracting" the top painting and enhancing the bottom one, and believes an even more advanced system is possible.

  12. Gas separating

    DOEpatents

    Gollan, A.

    1988-03-29

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  13. In-line coupling of an aptamer based miniaturized monolithic affinity preconcentration unit with capillary electrophoresis and Laser Induced Fluorescence detection.

    PubMed

    Marechal, A; Jarrosson, F; Randon, J; Dugas, V; Demesmay, C

    2015-08-01

    A composite 30-cm capillary was prepared. The head of the capillary was a 1.5-cm original and miniaturized aptamer-based monolithic affinity support that was in-line coupled to the end of the capillary used for capillary electrophoresis (CE) with laser induced fluorescence (LIF) detection. The device was used for the preconcentration, separation and quantification of ochratoxin A (OTA) as a test solute. The 1.5-cm preconcentration unit consists of a fritless affinity monolithic bonded with 5'-SH-modified oligonucleotide aptamers. A vinyl spacer was used for thiol-ene photoclick chemistry with a 5min irradiation at 365nm. Photografting allowed to confine the binding reaction to the desired silica monolithic segment, upstream the empty section of the CE capillary using an UV mask. The photografting procedure was optimized preparing 10-cm capillary monoliths for nano-LC. The retention factors of cationic solutes in ion-exchange nano-LC allowed to follow the aptamer binding on the monolith. The reproducibility of the photografting process was satisfactory with inter-capillary variation lower than 10%. The aptamer bonding density can be increased by successive graftings of 100μM aptamer concentration solution (5pmol/cm/grafting). The optimal conditions to successfully perform the in-line coupling (preconcentration, elution and separation of OTA) with the composite capillary were adjusted depending on individual requirements of each step but also insuring compatibility. Under optimized conditions, OTA was successfully preconcentrated and quantified down to 0.1pg (percolation of 2.65μL of a 40ng/L OTA solution). A quantitative recovery of OTA (93±2%) was achieved in a single elution of 30pg percolated OTA amount. The reproducibility of the overall process was satisfactory with a relative standard deviation lower than 10% with negligible non-specific adsorption. This device was applied for the preconcentration and analysis of OTA in beer and wine at the ppb level within

  14. REMOVAL OF CRYPTOSPORIDIUM BY IN-LINE FILTRATION: EFFECTS OF COAGULANT TYPE, FILTER LOADING RATE AND TEMPERATURE

    EPA Science Inventory

    Eight pilot-scale runs were performed to evaluate the impacts of temperature, coagulant type and filter loading rates on the removal of Cryptosporidium oocysts through in-line filtration. The study was set up as a 2(3) factorial design, which allowed investigation of all possible...

  15. 47 CFR 25.261 - Procedures for avoidance of in-line interference events for Non Geostationary Satellite Orbit...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... interference events for Non Geostationary Satellite Orbit (NGSO) Satellite Network Operations in the Fixed... avoidance of in-line interference events for Non Geostationary Satellite Orbit (NGSO) Satellite Network... procedures in this section apply to non-Federal-Government NGSO FSS satellite networks operating in...

  16. 47 CFR 25.261 - Procedures for avoidance of in-line interference events for Non Geostationary Satellite Orbit...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... interference events for Non Geostationary Satellite Orbit (NGSO) Satellite Network Operations in the Fixed... avoidance of in-line interference events for Non Geostationary Satellite Orbit (NGSO) Satellite Network... procedures in this section apply to non-Federal-Government NGSO FSS satellite networks operating in...

  17. In-stream measurement of canola (Brassica napus L.) seed oil concentration using in-line near infrared reflectance spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural variation in the seed oil concentration of oilseed crops can impair a crushing plant’s ability to efficiently recover the oil from seed. Consequently, there is interest in using in-line near infrared (NIR) spectroscopy to measure the oil concentration of the seed to be processed and use thi...

  18. Artificial neural network ability in evaluation of random wave-induced inline force on a vertical cylinder

    NASA Astrophysics Data System (ADS)

    Lotfollahi-Yaghin, M. A.; Pourtaghi, A.; Sanaaty, B.; Lotfollahi-Yaghin, A.

    2012-03-01

    An approach based on artificial neural network (ANN) is used to develop predictive relations between hydrodynamic inline force on a vertical cylinder and some effective parameters. The data used to calibrate and validate the ANN models are obtained from an experiment. Multilayer feed-forward neural networks that are trained with the back-propagation algorithm are constructed by use of three design parameters (i.e. wave surface height, horizontal and vertical velocities) as network inputs and the ultimate inline force as the only output. A sensitivity analysis is conducted on the ANN models to investigate the generalization ability (robustness) of the developed models, and predictions from the ANN models are compared to those obtained from Morison equation which is usually used to determine inline force as a computational method. With the existing data, it is found that least square method (LSM) gives less error in determining drag and inertia coefficients of Morison equation. With regard to the predicted results agreeing with calculations achieved from Morison equation that used LSM method, neural network has high efficiency considering its convenience, simplicity and promptitude. The outcome of this study can contribute to reducing the errors in predicting hydrodynamic inline force by use of ANN and to improve the reliability of that in comparison with the more practical state of Morison equation. Therefore, this method can be applied to relevant engineering projects with satisfactory results.

  19. Composite battery separator

    NASA Technical Reports Server (NTRS)

    Edwards, Dean B. (Inventor); Rippel, Wally E. (Inventor)

    1987-01-01

    A composite battery separator comprises a support element (10) having an open pore structure such as a ribbed lattice and at least one liquid permeable sheet (20,22) to distribute the compressive force evenly onto the surfaces of the layers (24, 26) of negative active material and positive active material. In a non-flooded battery cell the compressible, porous material (18), such as a glass mat which absorbs the electrolyte, is compressed into a major portion of the pores or openings (16) in the support element. The unfilled pores in the material (18) form a gas diffusion path as the channels (41) formed between adjacent ribs in the lattice element (30,36). Facing two lattice elements (30, 31) with acute angled cross-ribs (34, 38) facing each other prevents the elements from interlocking and distorting a porous, separator (42) disposed between the lattice elements.

  20. Estimating genetic parameters for fertility in dairy cows from in-line milk progesterone profiles.

    PubMed

    Tenghe, A M M; Bouwman, A C; Berglund, B; Strandberg, E; Blom, J Y; Veerkamp, R F

    2015-08-01

    The aim of this study was to define endocrine fertility traits from in-line milk progesterone (P4) records and to estimate genetic parameters for these traits. Correlations of classical fertility (calving interval and calving to first service) and milk production traits with endocrine fertility traits were also estimated. In-line milk P4 records (n=160,952) collected from June 2009 through November 2013 for 2,273 lactations of 1,561 Holstein-Friesian cows in 12 commercial herds in the Netherlands were analyzed for (the log of) the number of days from calving till commencement of luteal activity (lnC-LA), proportion of samples between 25 and 60 d in milk with luteal activity (PLA), presence or absence of luteal activity for a cow between 25 and 60 d in milk, interval from commencement of luteal activity to first service (CLAFS), first luteal phase length, length of first interluteal interval, and length of first interovulatory interval. Milk P4 records were sampled, on average, every 2 d. Genetic parameters were estimated using a mixed linear animal model. Heritability estimates (±SE) of endocrine fertility traits were 0.12±0.05 for lnC-LA, 0.12±0.05 for PLA, and 0.11±0.06 for CLAFS, and their repeatability estimates were 0.29±0.04, 0.21±0.04, and 0.15±0.06, respectively. The genetic correlation of lnC-LA with PLA was -0.91±0.06 and with CLAFS was -0.56±0.25. The genetic correlations of lnC-LA were 0.26±0.33 with calving interval and 0.37±0.21 with calving to first service. Genetic correlations of the milk production traits with lnC-LA ranged from 0.04 to 0.18 and 0.07 to 0.65 with classical fertility traits. The phenotypic correlations of all endocrine fertility traits with milk production traits were close to zero (0.01 to 0.07). This study shows that in-line P4 records can be used to define and explore several heritable endocrine fertility traits in dairy cows and might help in selection for improved fertility. PMID:26004838

  1. An advanced AFM sensor for high-aspect ratio pattern profile in-line measurement

    NASA Astrophysics Data System (ADS)

    Watanabe, Masahiro; Baba, Shuichi; Nakata, Toshihiko; Kurenuma, Toru; Kuroda, Hiroshi; Hiroki, Takenori

    2006-03-01

    Design rule shrinkage and the wider adoption of new device structures such as STI, copper damascene interconnects, and deep trench structures have increased the necessity of in-line process monitoring of step heights and profiles of device structures. For monitoring active device patterns, not test patterns as in OCD, AFM is the only non-destructive 3D monitoring tool. The barriers to using AFM in-line monitoring are its slow throughput and the accuracy degradation associated with probe tip wear and spike noise caused by unwanted oscillation on the steep slopes of high-aspect-ratio patterns. Our proprietary AFM scanning method, Step in mode®, is the method best suited to measuring high-aspect-ratio pattern profiles. Because the probe is not dragged on the sample surface as in conventional AFM, the profile trace fidelity across steep slopes is excellent. Because the probe does not oscillate and hit the sample at a high frequency as in AC scanning mode, this mode is free from unwanted spurious noises on steep sample slopes and incurs extremely little probe tip wear. To fully take advantage of the above properties, we have developed an AFM sensor optimized for in-line use, which produces accurate profile data at high speeds. The control scheme we have developed for the AFM sensor, which we call "Smart Step-in", elaborately analyses the contact force signal, enabling efficient probe tip scanning and a low and stable contact force. The mechanism of the AFM sensor has been optimized for the higher scanning rate and has improved the accuracy, such as the scanning planarity, position and height accuracy, and slope angle accuracy. Our prototype AFM sensor can scan high-aspect-ratio patterns while stabilizing the contact force at 3 nN. The step height measurement repeatability was 0.8 nm (3σ). A STI-like test pattern was scanned, and the steep sidewalls with angles of 84° were measured with high fidelity and without spurious noises.

  2. Enhancing Patient Understanding of Medical Procedures: Evaluation of an Interactive Multimedia Program with In-line Exercises

    PubMed Central

    Tait, Alan R.; Voepel-Lewis, Terri; Chetcuti, Stanley J.; Brennan-Martinez, Colleen; Levine, Robert

    2014-01-01

    Introduction Standard print and verbal information provided to patients undergoing treatments is often difficult to understand and may impair their ability to be truly informed. This study examined the effect of an interactive multimedia informational program with in-line exercises and corrected feedback on patients’ real-time understanding of their cardiac catheterization procedure. Methods 151 adult patients scheduled for diagnostic cardiac catheterization were randomized to receive information about their procedure using either the standard institutional verbal and written information (SI) or an interactive iPad-based informational program (IPI). Subject understanding was evaluated using semi-structured interviews at baseline, immediately following catheterization, and 2 weeks after the procedure. In addition, for those randomized to the IPI, the ability to respond correctly to several in-line exercises was recorded. Subjects’ perceptions of, and preferences for the information delivery were also elicited. Results Subjects randomized to the IPI program had significantly better understanding following the intervention compared with those randomized to the SI group (8.3 ± 2.4 vs 7.4 ± 2.5, respectively, 0–12 scale where 12 = complete understanding, P<0.05). First-time correct responses to the in-line exercises ranged from 24.3% – 100%. Subjects reported that the in-line exercises were very helpful (9.1 ± 1.7, 0–10 scale, where 10 = extremely helpful) and the iPad program very easy to use (9.0 ± 1.6, 0–10 scale, where 10 = extremely easy) suggesting good clinical utility. Discussion Results demonstrated the ability of an interactive multimedia program to enhance patients’ understanding of their medical procedure. Importantly, the incorporation of in-line exercises permitted identification of knowledge deficits, provided corrected feedback, and confirmed the patients’ understanding of treatment information in real-time when consent was sought

  3. Particle separation

    DOEpatents

    Moosmuller, Hans; Chakrabarty, Rajan K.; Arnott, W. Patrick

    2011-04-26

    Embodiments of a method for selecting particles, such as based on their morphology, is disclosed. In a particular example, the particles are charged and acquire different amounts of charge, or have different charge distributions, based on their morphology. The particles are then sorted based on their flow properties. In a specific example, the particles are sorted using a differential mobility analyzer, which sorts particles, at least in part, based on their electrical mobility. Given a population of particles with similar electrical mobilities, the disclosed process can be used to sort particles based on the net charge carried by the particle, and thus, given the relationship between charge and morphology, separate the particles based on their morphology.

  4. Particle separation

    NASA Technical Reports Server (NTRS)

    Moosmuller, Hans (Inventor); Chakrabarty, Rajan K. (Inventor); Arnott, W. Patrick (Inventor)

    2011-01-01

    Embodiments of a method for selecting particles, such as based on their morphology, is disclosed. In a particular example, the particles are charged and acquire different amounts of charge, or have different charge distributions, based on their morphology. The particles are then sorted based on their flow properties. In a specific example, the particles are sorted using a differential mobility analyzer, which sorts particles, at least in part, based on their electrical mobility. Given a population of particles with similar electrical mobilities, the disclosed process can be used to sort particles based on the net charge carried by the particle, and thus, given the relationship between charge and morphology, separate the particles based on their morphology.

  5. Battery separator

    SciTech Connect

    Giovannoni, R.T.; Kung, J.K.J.; Choi, W.M.

    1987-10-13

    This patent describes a battery system composed of at least one pair of electrodes of opposite polarity, an electrolyte and a separator positioned between electrodes of opposite polarity. The improvement comprises that the separator is a microporous sheet composed of a substantially uniform composition of A. from 7 to 50 weight percent of a polymer mixture, the mixture formed from (a) from about 95 to about 40 weight percent of polyolefin formed from ethylene, propylene or mixtures thereof or a mixture of the polyolefins having a weight average molecular weight of at least about 3,000,000; and (b) from about 5 to about 60 weight percent of a polymeric blend formed from a polyethylene terpolymer and a vinyl or vinylidene halide polymer in a weight ratio of 19:1 to 1:3, the polyethylene terpolymer formed from (1) ethylene monomer, (2) at least one ethylenically unsaturated organic monomer selected from the group consisting of esters of unsaturated C/sub 3/-C/sub 20/ mono- or dicarboxylic acids, vinyl esters of saturated C/sub 2/-C/sub 18/ carboxylic acids, vinyl alkyl ethers wherein the alkyl group has 1-18 carbon atoms, vinyl or vinylidene halides, acrylonitrile, methacrylonitrile, norbornene, alpha-olefins of 3-12 carbon atoms, and vinyl aromatic compounds, and, (3) an additional monomer selected from the group consisting of ethylenically unsaturated C/sub 3/-C/sub 20/ carboxylic acids, carbon monoxide, and sulfur dioxide; B. from 93 to 50 weight percent of a filler which is substantially inert with respect to the battery electrodes and electrolyte; and C. from 0 to 20 weight percent of plasticizer for at least one of the polymers of the composition.

  6. Miniature in-line photonic crystal fiber etalon fabricated by 157 nm laser micromachining.

    PubMed

    Ran, Z L; Rao, Y J; Deng, H Y; Liao, X

    2007-11-01

    A miniature in-line fiber-optic Fabry-Perot etalon is fabricated on a photonic crystal fiber (PCF) by using 157 nm laser micromachining for the first time to our knowledge. Experimental results show that such a PCF-based etalon has an excellent fringe visibility of up to approximately 26 dB due to the mirror-finish quality of the two cavity surfaces inside the PCF. This etalon can be used as an ideal sensor for precise strain measurement under high temperature of up to 800 degrees C. It can also offer some other outstanding advantages, such as fast and easy fabrication, high reproducibility, capacity of mass production, low cost, low temperature-strain cross-sensitivity, and high signal-to-noise ratio. PMID:17975600

  7. In-line fiber-optic etalon formed by hollow-core photonic crystal fiber.

    PubMed

    Rao, Y J; Zhu, T; Yang, X C; Duan, D W

    2007-09-15

    A novel fiber-optic in-line etalon formed by splicing a section of hollow-core photonic crystal fiber (HCPCF) in between two single-mode fibers is proposed and demonstrated, for the first time to our knowledge. Such a HCPCF-based etalon acts as an excellent optical waveguide to form a Fabry-Perot interferometer and hence allows the cavity length to be as long as several centimeters with good visibility as the transmission loss of the HCPCF is much smaller than that of a hollow core fiber; this offers great potential to generate a practical dense fiber-optic sensor network with spatial frequency division-multiplexing. This novel etalon is demonstrated for strain measurement, and the experimental results show that a good visibility of 0.3 and a strain accuracy of better than +/- 5 microepsilon are achieved. PMID:17873927

  8. An iterative method for robust in-line phase contrast imaging

    NASA Astrophysics Data System (ADS)

    Carroll, Aidan J.; van Riessen, Grant A.; Balaur, Eugeniu; Dolbnya, Igor P.; Tran, Giang N.; Peele, Andrew G.

    2016-04-01

    We present an iterative near-field in-line phase contrast method that allows quantitative determination of the thickness of an object given the refractive index of the sample material. The iterative method allows for quantitative phase contrast imaging in regimes where the contrast transfer function (CTF) and transport of intensity equation (TIE) cannot be applied. Further, the nature of the iterative scheme offers more flexibility and potentially allows more high-resolution image reconstructions when compared to TIE method and less artefacts when compared to the CTF method. While, not addressed here, extension of our approach in future work to broadband illumination will also be straightforward as the wavelength dependence of the refractive index of an object can be readily incorporated into the iterative approach.

  9. A fast-converging iterative method for X-ray in-line phase contrast tomography

    SciTech Connect

    Vo, Nghia T.; Breese, Mark B. H.; Atwood, Robert C.; Drakopoulos, Michael; Moser, Herbert O.; Lee, Peter D.

    2012-11-26

    X-ray in-line phase contrast tomography holds great promise for the quantitative analysis of soft materials. However, its applications have been limited, so far, by the fact that direct methods based on the transport-of-intensity equation and the contrast transfer function are sensitive to noise and applicable only to limited types of samples. Here, we propose an iterative method based on the Gerchberg-Saxton algorithm (R. W. Gerchberg and W. O. Saxton, Optik 35, 237 (1972)), but overcoming its slow convergence by an acceleration technique, named random signed feedback, which shows an excellent performance, both in numerical simulation and tomographic experiment, of discriminating various polymers even when using 53 keV synchrotron X-rays.

  10. Morphological analysis of GeTe in inline phase change switches

    SciTech Connect

    King, Matthew R.; El-Hinnawy, Nabil; Salmon, Mike; Gu, Jitty; Wagner, Brian P.; Jones, Evan B.; Howell, Robert S.; Nichols, Doyle T.; Young, Robert M.; Borodulin, Pavel

    2015-09-07

    Crystallization and amorphization phenomena in indirectly heated phase change material-based devices were investigated. Scanning transmission electron microscopy was utilized to explore GeTe phase transition processes in the context of the unique inline phase change switch (IPCS) architecture. A monolithically integrated thin film heating element successfully converted GeTe to ON and OFF states. Device cycling prompted the formation of an active area which sustains the majority of structural changes during pulsing. A transition region on both sides of the active area consisting of polycrystalline GeTe and small nuclei (<15 nm) in an amorphous matrix was also observed. The switching mechanism, determined by variations in pulsing parameters, was shown to be predominantly growth-driven. A preliminary model for crystallization and amorphization in IPCS devices is presented.

  11. In-line interferometer for direction-sensitive displacement measurements by optical feedback detection

    SciTech Connect

    Tarun, Alvarado; Jecong, Julius; Saloma, Caesar

    2005-12-01

    We demonstrate a compact in-line interferometer for direction-sensitive displacement measurement by optical feedback detection with a semiconductor laser (SL) light source. Two reflected beams from a semitransparent reference mirror and a reflecting test object interfere in the SL medium, causing a variation in its output power. The reference mirror is located between the SL output facet and the test object. The performance of the interferometer is investigated numerically and experimentally to determine its optimal operating conditions. We have verified the operating conditions where the behavior of the SL output power profile could indicate accurately the displacement magnitude and direction of the moving test object. The profile behavior is robust against variations in optical feedback and scale of the interferometer configuration.

  12. Synthetic aperture in terahertz in-line digital holography for resolution enhancement.

    PubMed

    Huang, Haochong; Rong, Lu; Wang, Dayong; Li, Weihua; Deng, Qinghua; Li, Bin; Wang, Yunxin; Zhan, Zhiqiang; Wang, Xuemin; Wu, Weidong

    2016-01-20

    Terahertz digital holography is a combination of terahertz technology and digital holography. In digital holography, the imaging resolution is the key parameter in determining the detailed quality of a reconstructed wavefront. In this paper, the synthetic aperture method is used in terahertz digital holography and the in-line arrangement is built to perform the detection. The resolved capability of previous terahertz digital holographic systems restricts this technique to meet the requirement of practical detection. In contrast, the experimental resolved power of the present method can reach 125 μm, which is the best resolution of terahertz digital holography to date. Furthermore, the basic detection of a biological specimen is conducted to show the practical application. In all, the results of the proposed method demonstrate the enhancement of experimental imaging resolution and that the amplitude and phase distributions of the fine structure of samples can be reconstructed by using terahertz digital holography. PMID:26835956

  13. Microbubbles as contrast agent for in-line x-ray phase-contrast imaging

    SciTech Connect

    Xi Yan; Zhao Jun; Tang Rongbiao; Wang Yujie

    2011-07-04

    In the present study, we investigated the potential of gas-filled microbubbles as contrast agents for in-line x-ray phase-contrast imaging (PCI) in biomedical applications. When imaging parameters are optimized, the microbubbles function as microlenses that focus the incoming x-rays to form bright spots, which can significantly enhance the image contrast. Since microbubbles have been shown to be safe contrast agents in clinical ultrasonography, this contrast-enhancement procedure for PCI may have promising utility in biomedical applications, especially when the dose of radiation is a serious concern. In this study, we performed both numerical simulations and ex vivo experiments to investigate the formation of the contrast and the effectiveness of microbubbles as contrast agents in PCI.

  14. High-speed, compact, adaptive lenses using in-line transparent dielectric elastomer actuator membranes

    NASA Astrophysics Data System (ADS)

    Shian, Samuel; Diebold, Roger M.; Clarke, David R.

    2013-04-01

    Electrically tunable adaptive lenses provide several advantages over traditional lens assemblies in terms of compactness, speed, efficiency, and flexibility. We present an elastomer-liquid lens system which makes use of an in-line, transparent electroactive polymer actuator. The lens has two liquid-filled cavities enclosed within two frames, with two passive outer elastomer membranes and an internal transparent electroactive membrane. Advantages of the lens design over existing systems include large apertures, flexibility in choosing the starting lens curvature, and electrode encapsulation with a dielectric liquid. A lens power change up to 40 diopters, corresponding to focal length variation up to 300%, was recorded during actuation, with a response time on the order of tens of milliseconds.

  15. Sparsity-Based Pixel Super Resolution for Lens-Free Digital In-line Holography

    NASA Astrophysics Data System (ADS)

    Song, Jun; Leon Swisher, Christine; Im, Hyungsoon; Jeong, Sangmoo; Pathania, Divya; Iwamoto, Yoshiko; Pivovarov, Misha; Weissleder, Ralph; Lee, Hakho

    2016-04-01

    Lens-free digital in-line holography (LDIH) is a promising technology for portable, wide field-of-view imaging. Its resolution, however, is limited by the inherent pixel size of an imaging device. Here we present a new computational approach to achieve sub-pixel resolution for LDIH. The developed method is a sparsity-based reconstruction with the capability to handle the non-linear nature of LDIH. We systematically characterized the algorithm through simulation and LDIH imaging studies. The method achieved the spatial resolution down to one-third of the pixel size, while requiring only single-frame imaging without any hardware modifications. This new approach can be used as a general framework to enhance the resolution in nonlinear holographic systems.

  16. Sparsity-Based Pixel Super Resolution for Lens-Free Digital In-line Holography

    PubMed Central

    Song, Jun; Leon Swisher, Christine; Im, Hyungsoon; Jeong, Sangmoo; Pathania, Divya; Iwamoto, Yoshiko; Pivovarov, Misha; Weissleder, Ralph; Lee, Hakho

    2016-01-01

    Lens-free digital in-line holography (LDIH) is a promising technology for portable, wide field-of-view imaging. Its resolution, however, is limited by the inherent pixel size of an imaging device. Here we present a new computational approach to achieve sub-pixel resolution for LDIH. The developed method is a sparsity-based reconstruction with the capability to handle the non-linear nature of LDIH. We systematically characterized the algorithm through simulation and LDIH imaging studies. The method achieved the spatial resolution down to one-third of the pixel size, while requiring only single-frame imaging without any hardware modifications. This new approach can be used as a general framework to enhance the resolution in nonlinear holographic systems. PMID:27098438

  17. A fast-converging iterative method for X-ray in-line phase contrast tomography

    NASA Astrophysics Data System (ADS)

    Vo, Nghia T.; Atwood, Robert C.; Moser, Herbert O.; Lee, Peter D.; Breese, Mark B. H.; Drakopoulos, Michael

    2012-11-01

    X-ray in-line phase contrast tomography holds great promise for the quantitative analysis of soft materials. However, its applications have been limited, so far, by the fact that direct methods based on the transport-of-intensity equation and the contrast transfer function are sensitive to noise and applicable only to limited types of samples. Here, we propose an iterative method based on the Gerchberg-Saxton algorithm (R. W. Gerchberg and W. O. Saxton, Optik 35, 237 (1972)), but overcoming its slow convergence by an acceleration technique, named random signed feedback, which shows an excellent performance, both in numerical simulation and tomographic experiment, of discriminating various polymers even when using 53 keV synchrotron X-rays.

  18. In-line drivetrain and four wheel drive work machine using same

    DOEpatents

    Hoff, Brian

    2008-08-05

    A four wheel drive articulated mine loader is powered by a fuel cell and propelled by a single electric motor. The drivetrain has the first axle, second axle, and motor arranged in series on the work machine chassis. Torque is carried from the electric motor to the back differential via a pinion meshed with the ring gear of the back differential. A second pinion oriented in an opposite direction away from the ring gear is coupled to a drive shaft to transfer torque from the ring gear to the differential of the front axle. Thus, the ring gear of the back differential acts both to receive torque from the motor and to transfer torque to the forward axle. The in-line drive configuration includes a single electric motor and a single reduction gear to power the four wheel drive mine loader.

  19. Digital in-line X-ray holography with zone plates.

    PubMed

    Heine, R; Gorniak, T; Nisius, T; Christophis, C; Pettitt, M E; Staier, F; Wilhein, T; Rehbein, S; Grunze, M; Rosenhahn, A

    2011-07-01

    Single pulse imaging with radiation provided by free-electron laser sources is a promising approach towards X-ray microscopy, which is expected to provide high resolution images of biological samples unaffected by radiation damage. One fully coherent imaging technique for this purpose is digital in-line holography. Key to its successful application is the creation of X-ray point sources with high photon flux. In this study we applied zone plates to create such point sources with synchrotron radiation provided by the storage ring BESSY II. The obtained, divergent light cone is applied to holographic microscopy of biological objects such as critical point dried Navicula perminuta diatoms and human cells using photons with an energy of 250 eV. Compared to conventional experiments employing pinholes, exposure times are reduced by two orders of magnitude. PMID:21740876

  20. Compressive sensing sectional imaging for single-shot in-line self-interference incoherent holography

    NASA Astrophysics Data System (ADS)

    Weng, Jiawen; Clark, David C.; Kim, Myung K.

    2016-05-01

    A numerical reconstruction method based on compressive sensing (CS) for self-interference incoherent digital holography (SIDH) is proposed to achieve sectional imaging by single-shot in-line self-interference incoherent hologram. The sensing operator is built up based on the physical mechanism of SIDH according to CS theory, and a recovery algorithm is employed for image restoration. Numerical simulation and experimental studies employing LEDs as discrete point-sources and resolution targets as extended sources are performed to demonstrate the feasibility and validity of the method. The intensity distribution and the axial resolution along the propagation direction of SIDH by angular spectrum method (ASM) and by CS are discussed. The analysis result shows that compared to ASM the reconstruction by CS can improve the axial resolution of SIDH, and achieve sectional imaging. The proposed method may be useful to 3D analysis of dynamic systems.