Rapid optimization method of the strong stray light elimination for extremely weak light signal detection.

PubMed

Wang, Geng; Xing, Fei; Wei, Minsong; You, Zheng

2017-10-16

The strong stray light has huge interference on the detection of weak and small optical signals, and is difficult to suppress. In this paper, a miniaturized baffle with angled vanes was proposed and a rapid optimization model of strong light elimination was built, which has better suppression of the stray lights than the conventional vanes and can optimize the positions of the vanes efficiently and accurately. Furthermore, the light energy distribution model was built based on the light projection at a specific angle, and the light propagation models of the vanes and sidewalls were built based on the Lambert scattering, both of which act as the bias of a calculation method of stray light. Moreover, the Monte-Carlo method was employed to realize the Point Source Transmittance (PST) simulation, and the simulation result indicated that it was consistent with the calculation result based on our models, and the PST could be improved by 2-3 times at the small incident angles for the baffle designed by the new method. Meanwhile, the simulation result was verified by laboratory tests, and the new model with derived analytical expressions which can reduce the simulation time significantly.

30 CFR 77.1001 - Stripping; loose material.

Code of Federal Regulations, 2010 CFR

2010-07-01

....1001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES... angle of repose, or barriers, baffle boards, screens, or other devices be provided that afford...

rotational Raman spectroscopy methods for probing energy thermalisation processes during spin-exchange optical pumping

NASA Astrophysics Data System (ADS)

Newton, Hayley; Walkup, Laura L.; Whiting, Nicholas; West, Linda; Carriere, James; Havermeyer, Frank; Ho, Lawrence; Morris, Peter; Goodson, Boyd M.; Barlow, Michael J.

2014-05-01

Spin-exchange optical pumping (SEOP) has been widely used to produce enhancements in nuclear spin polarisation for hyperpolarised noble gases. However, some key fundamental physical processes underlying SEOP remain poorly understood, particularly in regards to how pump laser energy absorbed during SEOP is thermalised, distributed and dissipated. This study uses in situ ultra-low frequency Raman spectroscopy to probe rotational temperatures of nitrogen buffer gas during optical pumping under conditions of high resonant laser flux and binary Xe/N2 gas mixtures. We compare two methods of collecting the Raman scattering signal from the SEOP cell: a conventional orthogonal arrangement combining intrinsic spatial filtering with the utilisation of the internal baffles of the Raman spectrometer, eliminating probe laser light and Rayleigh scattering, versus a new in-line modular design that uses ultra-narrowband notch filters to remove such unwanted contributions. We report a ~23-fold improvement in detection sensitivity using the in-line module, which leads to faster data acquisition and more accurate real-time monitoring of energy transport processes during optical pumping. The utility of this approach is demonstrated via measurements of the local internal gas temperature (which can greatly exceed the externally measured temperature) as a function of incident laser power and position within the cell.

Multiple-Cone Sunshade for a Spaceborne Telescope

NASA Technical Reports Server (NTRS)

Cafferty, Terry; Ford, Virginia

2008-01-01

A document describes a sunshade assembly for the spaceborne telescope of the Terrestrial Planet Finder Coronagraph mission. During operation, the telescope is aimed at target stars in the semihemisphere away from the Earth's Sun. The observatory rotates about its pointing axis during a single star observation, resulting in relative movement of the Sun. The sunshade assembly protects the telescope against excessive solar-induced thermal distortions for times long enough to complete observations. The assembly includes a cylindrical baffle immediately surrounding the telescope, and a series of coaxial conical shields at half-cone angle increments of between 3 and 6. The black inner surface of the cylindrical baffle suppresses stray light. The outer surface of the cylindrical baffle and all the surfaces of the conical shields except the outermost one are specular and highly reflective in the infrared. The outer surface of the outer shield is a material with low solar absorptance and high infrared emittance, such as silverized Teflon or white paint. This arrangement strongly radiatively couples each shield layer more effectively to cold space than to adjacent shield layers. The result is that the solar-driven temperature gradients in the cylindrical baffle are nearly negated, and only weakly communicated to the highly-infrared-reflective face of the primary telescope mirror.

Aerodynamics of an Axisymmetric Missile Concept Having Cruciform Strakes and In-Line Tail Fins From Mach 0.60 to 4.63

NASA Technical Reports Server (NTRS)

Allen, Jerry M.

2005-01-01

An experimental study has been performed to develop a large force and moment aerodynamic data set on a slender axisymmetric missile configuration having cruciform strakes and in-line control tail fins. The data include six-component balance measurements of the configuration aerodynamics and three-component measurements on all four tail fins. The test variables include angle of attack, roll angle, Mach number, model buildup, strake length, nose size, and tail fin deflection angles to provide pitch, yaw, and roll control. Test Mach numbers ranged from 0.60 to 4.63. The entire data set is presented on a CD-ROM that is attached to this paper. The CD-ROM also includes extensive plots of both the six-component configuration data and the three-component tail fin data. Selected samples of these plots are presented in this paper to illustrate the features of the data and to investigate the effects of the test variables.

Aerodynamics of an Axisymmetric Missile Concept Having Cruciform Strakes and In-Line Tail Fins From Mach 0.60 to 4.63, Supplement

NASA Technical Reports Server (NTRS)

Allen, Jerry M.

2005-01-01

An experimental study has been performed to develop a large force and moment aerodynamic data set on a slender axisymmetric missile configuration having cruciform strakes and in-line control tail fins. The data include six-component balance measurements of the configuration aerodynamics and three-component measurements on all four tail fins. The test variables include angle of attack, roll angle, Mach number, model buildup, strake length, nose size, and tail fin deflection angles to provide pitch, yaw, and roll control. Test Mach numbers ranged from 0.60 to 4.63. The entire data set is presented on a CD-ROM that is attached to this paper. The CD-ROM also includes extensive plots of both the six-component configuration data and the three-component tail fin data. Selected samples of these plots are presented in this paper to illustrate the features of the data and to investigate the effects of the test variables.

Effect of Six Missile-Bay Baffle Configurations and a Rocket End Plate on Ejection Releases of an MB-1 Rocket from a 0.05 Scale Model of the Convair F-106A Airplane

NASA Technical Reports Server (NTRS)

Hinson, William F.; Lee, John B.

1959-01-01

As a continuation of an investigation of the release characteristics of an MB-1 rocket carried internally by the Convair F-106A airplane, six missile-bay baffle configurations and a rocket end plate have been investigated in the 27- by 27-inch preflight jet of the NASA Wallops Station. The MB-1 rocket used had retractable fins and was ejected from a missile bay modified by the addition of six different baffle configurations. For some tests a rocket end plate was added to the model. Dynamically scaled models (0.04956 scale) were tested at a simulated altitude of 22,450 feet and Mach numbers of 0.86, 1.59, and 1.98, and at a simulated altitude of 29,450 feet and a Mach number of 1.98. The results of this investigation indicate that the missile-bay baffle configurations and the rocket end plate may be used to reduce the positive pitch amplitude of the MB-1 rocket after release. The initial negative pitching velocity applied to the MB-1 rocket might then be reduced in order to maintain a near-level-flight attitude after release. As the fuselage angle of attack is increased, the negative pitch amplitude of the rocket is decreased.

Impact of novel shift handle laparoscopic tool on wrist ergonomics and task performance

PubMed Central

Yu, Denny; Lowndes, Bethany; Morrow, Missy; Kaufman, Kenton; Bingener, Juliane; Hallbeck, Susan

2015-01-01

Background Laparoscopic tool handles causing wrist flexion and extension more than 15° from neutral are considered “at-risk” for musculoskeletal strain. Therefore this study measured the impact of laparoscopic tool handle angles on wrist postures and task performance. Methods Eight surgeons performed standard and modified Fundamentals of Laparoscopic Surgery (FLS) tasks with laparoscopic tools. Tool A had three adjustable handle angle configurations, i.e., in-line 0° (A0), 30° (A30), and pistol-grip 70° (A70). Tool B was a fixed pistol-grip grasper. Participants performed FLS peg transfer, inverted peg transfer, and inverted circle-cut with each tool and handle angle. Inverted tasks were adapted from standard FLS tasks to simulate advanced tasks observed during abdominal wall surgeries, e.g., ventral hernia. Motion tracking, video-analysis, and modified NASA-TLX workload questionnaires were used to measure postures, performance (e.g., completion time and errors), and workload. Results Task performance did not differ among tools. For FLS peg transfer, self-reported physical workload was lower for B than A70, and mean wrist postures showed significantly higher flexion for in-line than pistol-grip tools (B and A70). For inverted peg transfer, workload was higher for all configurations. However, less time was spent in at-risk wrist postures for in-line (47%) than pistol-grip (93-94%), and most participants preferred Tool A. For inverted circle cut, workload did not vary across configurations, mean wrist posture was 10° closer to neutral for A0 than B, and median time in at-risk wrist postures was significantly less for A0 (43%) than B (87%). Conclusion The best ergonomic wrist positions for FLS (floor) tasks are provided by pistol-grip tools and for tasks on the abdominal wall (ventral surface) by in-line handles. Adjustable handle angle laparoscopic tools can reduce ergonomic risks for musculoskeletal strain and allow versatility for tasks alternating between the floor and ceiling positions in a surgical trainer without impacting performance. PMID:26541720

Impact of novel shift handle laparoscopic tool on wrist ergonomics and task performance.

PubMed

Yu, Denny; Lowndes, Bethany; Morrow, Missy; Kaufman, Kenton; Bingener, Juliane; Hallbeck, Susan

2016-08-01

Laparoscopic tool handles causing wrist flexion and extension more than 15° from neutral are considered "at risk" for musculoskeletal strain. Therefore, this study measured the impact of laparoscopic tool handle angles on wrist postures and task performance. Eight surgeons performed standard and modified Fundamentals of Laparoscopic Surgery (FLS) tasks with laparoscopic tools. Tool A had three adjustable handle angle configurations, i.e., in-line 0° (A0), 30° (A30), and pistol-grip 70° (A70). Tool B was a fixed pistol-grip grasper. Participants performed FLS peg transfer, inverted peg transfer, and inverted circle cut with each tool and handle angle. Inverted tasks were adapted from standard FLS tasks to simulate advanced tasks observed during abdominal wall surgeries, e.g., ventral hernia. Motion tracking, video analysis, and modified NASA-TLX workload questionnaires were used to measure postures, performance (e.g., completion time and errors), and workload. Task performance did not differ between tools. For FLS peg transfer, self-reported physical workload was lower for B than for A70, and mean wrist postures showed significantly higher flexion for in-line than for pistol-grip tools (B and A70). For inverted peg transfer, workload was higher for all configurations. However, less time was spent in at-risk wrist postures for in-line (47 %) than for pistol-grip (93-94 %), and most participants preferred Tool A. For inverted circle cut, workload did not vary across configurations, mean wrist posture was 10° closer to neutral for A0 than B, and median time in at-risk wrist postures was significantly less for A0 (43 %) than for B (87 %). The best ergonomic wrist positions for FLS (floor) tasks are provided by pistol-grip tools and for tasks on the abdominal wall (ventral surface) by in-line handles. Adjustable handle angle laparoscopic tools can reduce ergonomic risks of musculoskeletal strain and allow versatility for tasks alternating between the floor and ceiling positions in a surgical trainer without impacting performance.

Improved flight-simulator viewing lens

NASA Technical Reports Server (NTRS)

Kahlbaum, W. M.

1979-01-01

Triplet lens system uses two acrylic plastic double convex lenses and one polystyrene plastic single convex lens to reduce chromatic distortion and lateral aberation, especially at large field angles within in-line systems of flight simulators.

Physics of the zero- photonic gap: fundamentals and latest developments

NASA Astrophysics Data System (ADS)

Zhou, Lei; Song, Zhengyong; Huang, Xueqin; Chan, C. T.

2012-12-01

A short overview is presented on the research works related to the zero- gap, which appears as the volume-averaged refraction index vanishes in photonic structures containing both positive and negative-index materials. After introducing the basic concept of the zero- gap based on both rigorous mathematics and numerical simulations, the unique properties of such a band gap are discussed, including its robustness against weak disorder, wide-incidence-angle operation and scaling invariance, which do not belong to a conventional Bragg gap. We then describe the simulation and experimental verifications on the zero- gap and its extraordinary properties in different frequency domains. After that, the unusual photonic and physical effects discovered based on the zero- gap and their potential applications are reviewed, including beam manipulations and nonlinear effects. Before concluding this review, several interesting ideas inspired from the zero- gap works will be introduced, including the zero-phase gaps, zero-permittivity and zero-permeability gaps, complete band gaps, and zero-refraction-index materials with Dirac-Cone dispersion.

Numerical exploration of non-axisymmetric divertor closure in the small angle slot (SAS) divertor at DIII-D

DOE PAGES

Frerichs, H.; Schmitz, O.; Covele, B.; ...

2018-02-28

Numerical simulations of toroidal asymmetries in a tightly baffled small angle slot (SAS) divertor on the DIII-D tokamak show that toroidal asymmetries in divertor closure result in (non-axisymmetric) local onset of detachment within a density window of 10-15% on top of the nominal threshold separatrix density. The SAS divertor is explored at DIII-D for improving access to cold, dissipative/detached divertor conditions. The narrow width of the slot divertor coupled with a small magnetic field line-to-target angle facilitates the buildup of neutral density, thereby increasing radiative and neutrals-related (atoms and molecules) losses in the divertor. Therefore, small changes in the strikemore » point location can be expected to have a large impact on diverter conditions. The combination of misaligned slot structure and non-axisymmetric perturbations to the magnetic field configuration causes the strike point to move along the divertor target plate, possibly leaving the diverter slot at some locations. The latter extreme case essentially introduces an opening in the divertor slot from where recycling neutrals can easily escape, and thereby degrade the performance of the slot divertor. Such a strike point dislocation is approximated by a finite gap in the divertor baffle for which three dimensional edge plasma and neutral gas simulations are performed with the EMC3-EIRENE code.« less

Numerical exploration of non-axisymmetric divertor closure in the small angle slot (SAS) divertor at DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frerichs, H.; Schmitz, O.; Covele, B.

Numerical simulations of toroidal asymmetries in a tightly baffled small angle slot (SAS) divertor on the DIII-D tokamak show that toroidal asymmetries in divertor closure result in (non-axisymmetric) local onset of detachment within a density window of 10-15% on top of the nominal threshold separatrix density. The SAS divertor is explored at DIII-D for improving access to cold, dissipative/detached divertor conditions. The narrow width of the slot divertor coupled with a small magnetic field line-to-target angle facilitates the buildup of neutral density, thereby increasing radiative and neutrals-related (atoms and molecules) losses in the divertor. Therefore, small changes in the strikemore » point location can be expected to have a large impact on diverter conditions. The combination of misaligned slot structure and non-axisymmetric perturbations to the magnetic field configuration causes the strike point to move along the divertor target plate, possibly leaving the diverter slot at some locations. The latter extreme case essentially introduces an opening in the divertor slot from where recycling neutrals can easily escape, and thereby degrade the performance of the slot divertor. Such a strike point dislocation is approximated by a finite gap in the divertor baffle for which three dimensional edge plasma and neutral gas simulations are performed with the EMC3-EIRENE code.« less

Numerical exploration of non-axisymmetric divertor closure in the small angle slot (SAS) divertor at DIII-D

NASA Astrophysics Data System (ADS)

Frerichs, H.; Schmitz, O.; Covele, B.; Feng, Y.; Guo, H. Y.; Hill, D.

2018-05-01

Numerical simulations of toroidal asymmetries in a tightly baffled small angle slot (SAS) divertor on the DIII-D tokamak show that toroidal asymmetries in divertor closure result in (non-axisymmetric) local onset of detachment within a density window of 10-15% on top of the nominal threshold separatrix density. The SAS divertor is explored at DIII-D for improving access to cold, dissipative/detached divertor conditions. The narrow width of the slot divertor coupled with a small magnetic field line-to-target angle facilitates the buildup of neutral density, thereby increasing radiative and neutrals-related (atoms and molecules) losses in the divertor. Small changes in the strike point location can be expected to have a large impact on divertor conditions. The combination of misaligned slot structure and non-axisymmetric perturbations to the magnetic field configuration causes the strike point to move along the divertor target plate, possibly leaving the divertor slot at some locations. The latter extreme case essentially introduces an opening in the divertor slot from where recycling neutrals can easily escape, and thereby degrade the performance of the slot divertor. Such a strike point dislocation is approximated by a finite gap in the divertor baffle for which 3D edge plasma and neutral gas simulations are performed with the EMC3-EIRENE code.

Multiplexed two in-line holographic recordings for flow characterization in a flexible vessel

NASA Astrophysics Data System (ADS)

Lobera, Julia; Palero, Virginia; Roche, Eva M.; Gómez Climente, Marina; López Torres, Ana M.; Andrés, Nieves; Arroyo, M. Pilar

2017-06-01

The simultaneous presence of the real and virtual images in the hologram reconstruction is inherent in the in-line holography. This drawback can be overcome with a shifted knife-edge aperture at the focal plane of the imaging lens. The shifted aperture DIH produces holograms where the real and virtual images are completely separated. In this paper we propose a modification of the shifted aperture DIH that allows recording two holograms simultaneously using one camera, while retaining the simplicity of the in-line configuration and the advantage of the shifted-aperture strategy. As in typical stereoscopy, the advantage of this configuration is limited by the angle between the two illuminating beams, and therefore the aperture size. Some improvement on the out-of-plane resolution can be expected from a combined analysis of the multiplexed holograms. In order to compare this technique with other in-line holographic configurations, several experiments have been performed to study the spatial resolution along the optical axis. The capabilities of the different techniques for characterizing the flow in a flexible and transparent model of a carotid bifurcation are also investigated.

Evaluation of the tablets' surface flow velocities in pan coaters.

PubMed

Dreu, Rok; Toschkoff, Gregor; Funke, Adrian; Altmeyer, Andreas; Knop, Klaus; Khinast, Johannes; Kleinebudde, Peter

2016-09-01

The tablet pan coating process involves various types of transverse tablet bed motions, ranging from rolling to cascading. To preserve satisfactory results in terms of coating quality after scale-up, understanding the dynamics of pan coating process should be achieved. The aim of this study was to establish a methodology of estimating translational surface velocities of the tablets in a pan coater and to assess their dependence on the drum's filling degree, the pan speed, the presence of baffles and the selected tablet properties in a dry bed system and during coating while varying the drum's filling degree and the pan speed. Experiments were conducted on the laboratory scale and on the pilot scale in side-vented pan coaters. Surface movement of biconvex two-layer tablets was assessed before, during and after the process of active coating. In order to determine the tablets' surface flow velocities, a high-speed video of the tablet surface flow was recorded via a borescope inserted into the coating drum and analysed via a cross-correlation algorithm. The obtained tablet velocity data were arranged in a linear fashion as a function of the coating drum's radius and frequency. Velocity data obtained during coating were close to those of dry tablets after coating. The filling degree had little influence on the tablet velocity profile in a coating drum with baffles but clearly affected it in a coating drum without baffles. In most but not all cases, tablets with a lower static angle of repose had tablet velocity profiles with lower slopes than tablets with higher inter-tablet friction. This particular tablet velocity response can be explained by case specific values of tablet bed's dynamic angle of repose. Copyright © 2016 Elsevier B.V. All rights reserved.

Modeling of axial vibrational control technique for CdTe VGF crystal growth under controlled cadmium partial pressure

NASA Astrophysics Data System (ADS)

Avetissov, I.; Kostikov, V.; Meshkov, V.; Sukhanova, E.; Grishechkin, M.; Belov, S.; Sadovskiy, A.

2014-01-01

A VGF growth setup assisted by axial vibrations of baffle submerged into CdTe melt with controlled Cd partial pressure was designed. An influence of baffle shape on flow velocity map, temperature distribution in CdTe melt and interface shape of growing crystal was analyzed by numerical simulation and physical modeling. To produce the desirable shape of crystal melt interface we slant under different angles vertical generatrix in a cylindrical disk and made chasing on faceplates of a disk. It was ascertained that a disk with conical generatrix formed more intensive convective flows from a faceplate with larger diameter. It was shown that at CdTe VGF crystal growth rate about 10 mm/h application of AVC technique made it possible to produce convex interface for 2 in. crystal diameter.

Bidirectional reflectance distribution function of diffuse extreme ultraviolet scatterers and extreme ultraviolet baffle materials.

PubMed

Newell, M P; Keski-Kuha, R A

1997-08-01

Bidirectional reflectance distribution function (BRDF) measurements of a number of diffuse extreme ultraviolet (EUV) scatterers and EUV baffle materials have been performed with the Goddard EUV scatterometer. BRDF data are presented for white Spectralon SRS-99 at 121.6 nm; the data exhibit a non-Lambertian nature and a total hemispherical reflectance lower than 0.15. Data are also presented for an evaporated Cu black sample, a black Spectralon SRS-02 sample, and a Martin Optical Black sample at wavelengths of 58.4 and 121.6 nm and for angles of incidence of 15 degrees and 45 degrees. Overall Martin Optical Black exhibited the lowest BRDF characteristic, with a total hemispherical reflectance of the order of 0.01 and measured BRDF values as low as 2 x 10(-3) sr(-1).

BRDF measurements of sunshield and baffle materials for the IRAS telescope

NASA Technical Reports Server (NTRS)

Smith, S. M.

1982-01-01

Measurements of the far-infrared bidirectional reflectance distribution functions (BRDF) of four samples of Martin Black coating and one sample of gold coated aluminum from the telescope to be flown on the Infrared Astronomy Satellite (IRAS) are presented. At incidence angles near 35 deg Martin Black is a diffuse reflector at wavelengths as long as 36 microns. The gold coated aluminum sample from the IRAS sunshield has a visible grain which causes a strong diffraction enhancement of the BRDF at large nonspecular angles. This enhancement from the sunshield will increase the stray light level inside the telescope.

Measuring the light scattering and orientation of a spheroidal particle using in-line holography.

PubMed

Seo, Kyung Won; Byeon, Hyeok Jun; Lee, Sang Joon

2014-07-01

The light scattering properties of a horizontally and vertically oriented spheroidal particle under laser illumination are experimentally investigated using digital in-line holography. The reconstructed wave field shows the bright singular points as a result of the condensed beam formed by a transparent spheroidal particle acting as a lens. The in-plane (θ) and out-of-plane (ϕ) rotating angles of an arbitrarily oriented spheroidal particle are measured by using these scattering properties. As a feasibility test, the 3D orientation of a transparent spheroidal particle suspended in a microscale pipe flow is successfully reconstructed by adapting the proposed method.

Method and apparatus for the application of textile treatment compositions to textile materials

DOEpatents

Argyle, M.D.; Propp, W.A.

1998-01-20

A system is described for applying textile treatment compositions to textile materials. A conduit member is provided which includes a passageway having a first end, a second end, and a medial portion with a constricted (narrowed) region. The passageway may include at least one baffle having an opening there through. A yarn strand is then moved through the passageway. A textile treatment composition (a sizing agent or dye) dissolved in a carrier medium (a supercritical fluid or liquefied gas) is thereafter introduced into the constricted region, preferably at an acute angle relative to the passageway. The carrier medium expands inside the passageway which causes delivery of the treatment composition to the yarn. The treated yarn then passes through the baffle (if used) which facilitates drying of the yarn. During this process, a carrier gas can be introduced into the passageway to ensure the production of a smooth, dry product. 1 fig.

Method and apparatus for the application of textile treatment compositions to textile materials

DOEpatents

Argyle, Mark D.; Propp, William Alan

1998-01-01

A system for applying textile treatment compositions to textile materials. A conduit member is provided which includes a passageway having a first end, a second end, and a medial portion with a constricted (narrowed) region. The passageway may include at least one baffle having an opening therethrough. A yarn strand is then moved through the passageway. A textile treatment composition (a sizing agent or dye) dissolved in a carrier medium (a supercritical fluid or liquified gas) is thereafter introduced into the constricted region, preferably at an acute angle relative to the passageway. The carrier medium expands inside the passageway which causes delivery of the treatment composition to the yarn. The treated yarn then passes through the baffle (if used) which facilitates drying of the yarn. During this process, a carrier gas can be introduced into the passageway to ensure the production of a smooth, dry product.

Longitudinal Stability and Control Characteristics as Determined by the Rocket-model Technique for an Inline, Cruciform, Canard Missile Configuration with a Low-aspect-ratio Wing Having Trailing-edge Flap Controls for a Mach Number Range of 0.7 to 1.

NASA Technical Reports Server (NTRS)

Baber, Hal T , Jr; Moul, Martin T

1955-01-01

Two full-scale models of an inline, cruciform, canard missile configuration having a low-aspect-ratio wing equipped with flap-type controls were flight tested in order to determine the missile's longitudinal aerodynamic characteristics. Stability derivatives and control and drag characteristics are presented for a range of Mach number from 0.7 to 1.8. Nonlinear lift and moment curves were noted for the angle - of-attack range of this test (0 deg to 8 deg). The aerodynamic-center location for angles of attack near 50 remained nearly constant for supersonic speeds at 13.5 percent of the mean aerodynamic chord; whereas for angles of attack near 0 deg, there was a rapid forward movement of the aerodynamic center as the Mach number increased. At a control deflection of 0 deg, the missile's response to the longitudinal control was in an essentially fixed space plane which was not coincident with the pitch plane as a result of the missile rolling. As a consequence, stability characteristics were determined from the resultant of pitch and yaw motions. The damping-in-pitch derivatives for the two angle -of-attack ranges of the test are in close agreement and varied only slightly with Mach number. The horn-balanced trailing-edge flap was effective in producing angle of attack over the Mach number range.

Longitudinal Stability and Control Characteristics as Determined by the Rocket-Model Technique for an Inline, Cruciform, Canard Missile Configuration with a Low-Aspect-Ratio Wing Having Trailing-Edge Flap Controls for a Mach Number Range of 0.7 to 1.8

NASA Technical Reports Server (NTRS)

Baber, H. T., Jr.; Moul, M. T.

1955-01-01

Two full-scale models of an inline, cruciform, canard missile configuration having a low-aspect-ratio wing equipped with flap-type controls were flight tested in order to determine the missile's longitudinal aerodynamic characteristics. Stability derivatives and control and drag characteristics are presented for a range of Mach number from 0.7 to 1.8. Nonlinear lift and moment curves were noted for the angle-of-attack range of this test (0 deg to 8 deg ). The aerodynamic-center location for angles of attack near 5 deg remained nearly constant for supersonic speeds at 13.5 percent of the mean aerodynamic chord; whereas for angles of attack near O deg, there was a rapid forward movement of the aerodynamic center as the Mach number increased. At a control deflection of O deg, the missile's response to the longitudinal control was in an essentially fixed space plane which was not coincident with the pitch plane as a result of the missile rolling. As a consequence, stability characteristics were determined from the resultant of pitch and yaw motions. The damping-in-pitch derivatives for the two angle-of-attack ranges of the test are in close agreement and varied only slightly with Mach number. The horn-balanced trailing-edge flap was effective in producing angle of attack over the Mach number range.

Staged electrostatic precipitator

DOEpatents

Miller, Stanley J.; Almlie, Jay C.; Zhuang, Ye

2016-03-01

A device includes a chamber having an air inlet and an air outlet. The device includes a plurality of stages including at least a first stage adjacent a second stage. The plurality of stages are disposed in the chamber and each stage has a plurality of discharge electrodes disposed in an interior region and is bounded by an upstream baffle on an end proximate the air inlet and bounded by a downstream baffle on an end proximate the air outlet. Each stage has at least one sidewall between the upstream baffle and the downstream baffle. The sidewall is configured as a collection electrode and has a plurality of apertures disposed along a length between the upstream baffle and the downstream baffle. The upstream baffle of the first stage is positioned in staggered alignment relative to the upstream baffle of the second stage and the downstream baffle of the first stage are positioned in staggered alignment relative to the downstream baffle of the second stage.

Horizontal baffle for nuclear reactors

DOEpatents

Rylatt, John A.

1978-01-01

A horizontal baffle disposed in the annulus defined between the core barrel and the thermal liner of a nuclear reactor thereby physically separating the outlet region of the core from the annular area below the horizontal baffle. The horizontal baffle prevents hot coolant that has passed through the reactor core from thermally damaging apparatus located in the annulus below the horizontal baffle by utilizing the thermally induced bowing of the horizontal baffle to enhance sealing while accommodating lateral motion of the baffle base plate.

Effect of baffle spacing and baffle cut on thermal-hydraulic characteristics of the fluid flow

NASA Astrophysics Data System (ADS)

Chernyateva, R. R.

2018-01-01

This article presents the results of investigations of the influence of baffle spacing and baffle cut on the size of dead zone formed near the cross baffles using numerical simulation methods. It is showed the structure of an additional baffle plate which can be used to reduce the dead zone and smoother flow distribution over the cross section.

Scattered light characterization of FORTIS

NASA Astrophysics Data System (ADS)

McCandliss, Stephan R.; Carter, Anna; Redwine, Keith; Teste, Stephane; Pelton, Russell; Hagopian, John; Kutyrev, Alexander; Li, Mary J.; Moseley, S. Harvey

2017-08-01

We describe our efforts to build a Wide-Field Lyman alpha Geocoronal simulator (WFLaGs) for characterizing the end-to-end sensitivity of FORTIS (Far-UV Off Rowland-circle Telescope for Imaging and Spectroscopy) to scattered Lyman α emission from outside of the nominal (1/2 degree)2 field-of-view. WFLaGs is a 50 mm diameter F/1 aluminum parabolic collimator fed by a hollow cathode discharge lamp with a 80 mm clear MgF2 window housed in a vacuum skin. It creates emission over a 10 degree FOV. WFLaGS will allow us to validate and refine a recently developed scattered light model and verify our scatter light mitigation strategies, which will incorporate low scatter baffle materials, and possibly 3-d printed light traps, covering exposed scatter centers. We present measurements of scattering intensity of Lyman alpha as a function of angle with respect to the specular reflectance direction for several candidate baffle materials. Initial testing of WFLaGs will be described.

Removal of nutrients from septic tank effluent with baffle subsurface-flow constructed wetlands

Treesearch

Lihu Cui; Ying Ouyang; Weizhi Yang; Zhujian Huang; Qiaoling Xu; Guangwei Yu

2015-01-01

Three new baffle flow constructed wetlands (CWs), namely the baffle horizontal flow CW (Z1), baffle vertical flow CW (Z2) and baffle hybrid flow CW (Z3), along with one traditional horizontal subsurface flow CW (Z4) were designed to test the removal efficiency of nitrogen (N) and phosphorus (P) from the septic tank effluent under varying hydraulic retention times (HRTs...

Energy Loss, Velocity Distribution, and Temperature Distribution for a Baffled Cylinder Model

NASA Technical Reports Server (NTRS)

Brevoort, Maurice J

1937-01-01

A study has been made of the important principles involved in the operation of a baffle for an engine cylinder and shows that cooling can be improved by 20 percent by using a correctly designed baffle. Such a gain is as effective as a 65 percent increase in pressure drop across the standard baffle, which had a 1/4 inch clearance between baffle and fin tips.

Orientation of colonized sand flies Phlebotomus papatasi, P. duboscqi, and Lutzomyia longipalpis (Diptera: Psychodidae) to diverse honeys using a 3-chamber in-line olfactometer.

PubMed

Wasserberg, G; Kirsch, P; Rowton, E D

2014-06-01

A 3-chamber in-line olfactometer designed for use with sand flies is described and tested as a high-throughput method to screen honeys for attractiveness to Phlebotomus papatasi (four geographic isolates), P. duboscqi (two geographic isolates), and Lutzomyia longipalpis maintained in colonies at the Walter Reed Army Institute of Research. A diversity of unifloral honey odors were evaluated as a proxy for the natural floral odors that sand flies may use in orientation to floral sugar sources in the field. In the 3-chamber in-line olfactometer, the choice modules come directly off both sides of the release area instead of angling away as in the Y-tube olfactometer. Of the 25 honeys tested, five had a significant attraction for one or more of the sand fly isolates tested. This olfactometer and high-throughput method has utility for evaluating a diversity of natural materials with unknown complex odor blends that can then be down-selected for further evaluation in wind tunnels and/or field scenarios. © 2014 The Society for Vector Ecology.

Finite-span rotating wings: three-dimensional vortex formation and variations with aspect ratio

NASA Astrophysics Data System (ADS)

Carr, Z. R.; Chen, C.; Ringuette, M. J.

2013-02-01

We investigate experimentally the effect of aspect ratio ( [InlineMediaObject not available: see fulltext.] ) on the time-varying, three-dimensional flow structure of flat-plate wings rotating from rest at 45° angle of attack. Plates of [InlineMediaObject not available: see fulltext.] = 2 and 4 are tested in a 50 % by mass glycerin-water mixture, with a total rotation of ϕ = 120° and a matched tip Reynolds number of 5,000. The time-varying, three-component volumetric velocity field is reconstructed using phase-locked, phase-averaged stereoscopic digital particle image velocimetry in multiple, closely-spaced chordwise planes. The vortex structure is analyzed using the {Q}-criterion, helicity density, and spanwise quantities. For both [InlineMediaObject not available: see fulltext.] s, the flow initially consists of a connected and coherent leading-edge vortex (LEV), tip vortex (TV), and trailing-edge vortex (TEV) loop; the LEV increases in size with span and tilts aft. Smaller, discrete vortices are present in the separated shear layers at the trailing and tip edges, which wrap around the primary TEV and TV. After about ϕ = 20°, the outboard-span LEV lifts off the plate and becomes arch-like. A second, smaller LEV and the formation of corner vortex structures follow. For [InlineMediaObject not available: see fulltext.] = 4, the outboard LEV moves farther aft, multiple LEVs form ahead of it, and after about ϕ = 50° a breakdown of the lifted-off LEV and the TV occurs. However, for [InlineMediaObject not available: see fulltext.] = 2, the outboard LEV lift-off is not progressive, and the overall LEV-TV flow remains more coherent and closer to the plate, with evidence of breakdown late in the motion. Inboard of about 50 % span, the [InlineMediaObject not available: see fulltext.] = 4 LEV is stable for the motion duration. Up to approximately 60 % span, the [InlineMediaObject not available: see fulltext.] = 2 LEV is distinct from the TV and is similarly stable. The [InlineMediaObject not available: see fulltext.] = 2 LEV exhibits substantially higher spanwise vorticity and velocity. The latter possesses a "four-lobed" distribution at the periphery of the LEV core having adjacent positive (outboard) and negative (inboard) components, corresponding to a helical streamline structure. Both [InlineMediaObject not available: see fulltext.] s show substantial root-to-tip velocity aft of the stable LEV, which drives outboard spanwise vorticity flux; flux toward the root is also present in the front portion of the LEV. For [InlineMediaObject not available: see fulltext.] = 2, there is a strong flux of spanwise vorticity from the outboard LEV to the tip, which may mitigate LEV lift-off and is not found for [InlineMediaObject not available: see fulltext.] = 4. The TV circulation for each [InlineMediaObject not available: see fulltext.] is similar in magnitude and growth when plotted versus the chord lengths travelled by the tip, prior to breakdown. Streamwise vorticity due to the TV induces high spanwise velocity, and for [InlineMediaObject not available: see fulltext.] = 2, the tilted LEV creates further streamwise vorticity which corresponds well to spanwise-elongated regions of spanwise velocity. For [InlineMediaObject not available: see fulltext.] = 2, the TV influences a relatively greater portion of the span and is more coherent at later times, which coupled with the tilted LEV strongly contributes to the higher overall spanwise velocity and vorticity flux.

A study of resonant-cavity and fiberglass-filled parallel baffles as duct silencers. [for wind tunnels

NASA Technical Reports Server (NTRS)

Soderman, P. T.

1982-01-01

Acoustical performance and pressure drop were measured for two types of splitters designed to attenuate sound propagating in ducts - resonant-cavity baffles and fiberglass-filled baffles. Arrays of four baffles were evaluated in the 7- by 10-foot wind tunnel number 1 at Ames Research Center at flow speeds from 0 to 41 m/sec. The baffles were 2.1 m high, 305 to 406 mm thick, and 3.1 to 4.4 m long. Emphasis was on measurements of silencer insertion loss as affected by variations of such parameters as baffle length, baffle thickness, perforated skin geometry, cavity size and shape, cavity damping, wind speed, and acoustic field directivity. An analytical method for predicting silencer performance is described and compared with measurements. With the addition of cavity damping in the form of 25-mm foam linings, the insertion loss above 250 Hz of the resonant-cavity baffles was improved 2 to 7 db compared with the undamped baffles; the loss became equal to or greater than the insertion loss of comparable size fiberglass baffles at frequencies above 250 Hz. Variations of cavity size and shape showed that a series of cavities with triangular cross-sections (i.e., variable depth) were superior to cavities with rectangular cross sections (i.e., constant depth). In wind, the undamped, resonant-cavity baffles generated loud cavity-resonance tones; the tones could be eliminated by cavity damping.

Convective instability in a porous enclosure with a horizontal conducting baffle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, F.; Wang, C.Y.

1993-08-01

The study of heat transfer in a fluid-saturated porous medium is essential in a variety of practical situations, including thermal insulation design and geothermal energy utilization. The present paper studies the convective instability in a two-dimensional porous enclosure with a horizontal baffle protruding from one of the side walls. The vertical side walls are insulated, while the top and bottom surfaces are maintained at lower and higher constant temperatures, respectively. The present work considers a baffle of high conductivity. We assume the baffle temperature can be considered constant throughout. We ask, for a given enclosure aspect ratio, is the additionmore » of another physical constraint (such as lengthening a baffle) always stabilizing Is there an optimum baffle location and length such that the critical Rayleigh number is maximized In summary, several concluding remarks can be drawn in the following: (1) Other dimensions being same, a centered baffle always results in a more stable state than an off-centered baffle. (2) A full-length baffle, i.e., [beta]/[sigma] = 1, does not necessarily lead to greater stability. Instead, the value of ([beta]/[sigma])[sub max] is usually less than unity. For a centered baffle, the maximum R[sup c] occurs for [beta]/[sigma] [ge] ([beta]/[sigma])[sub max]; while for an off-centered baffle, the maximum R[sup c] occurs at ([beta]/[sigma])[sub max]. (3) The value of ([beta]/[sigma])[sub max] increases with [sigma]. 6 refs., 4 figs., 1 tab.« less

Thermal baffle for fast-breeder reacton

DOEpatents

Rylatt, John A.

1977-01-01

A liquid-metal-cooled fast-breeder reactor includes a bridge structure for separating hot outlet coolant from relatively cool inlet coolant consisting of an annular stainless steel baffle plate extending between the core barrel surrounding the core and the thermal liner associated with the reactor vessel and resting on ledges thereon, there being inner and outer circumferential webs on the lower surface of the baffle plate and radial webs extending between the circumferential webs, a stainless steel insulating plate completely covering the upper surface of the baffle plate and flex seals between the baffle plate and the ledges on which the baffle plate rests to prevent coolant from washing through the gaps therebetween. The baffle plate is keyed to the core barrel for movement therewith and floating with respect to the thermal liner and reactor vessel.

33 CFR 159.81 - Baffles.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Baffles. 159.81 Section 159.81 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.81 Baffles. Baffles in sewage retention tanks, if...

Hydrodynamic Regimes and Structures in Sloped Weir Baffled Culverts and Their Influence on Juvenile Salmon Passage.

DOT National Transportation Integrated Search

2007-07-01

The purpose of this study was to determine what hydraulic characteristics enhance or diminish : upstream juvenile salmon passage within a sloped-weir baffled culvert. The culvert slope, baffle : spacing, and baffle height were varied to observe flow ...

Vortex-induced vibrations of a flexible cylinder at large inclination angle

PubMed Central

Bourguet, Rémi; Triantafyllou, Michael S.

2015-01-01

The free vibrations of a flexible circular cylinder inclined at 80° within a uniform current are investigated by means of direct numerical simulation, at Reynolds number 500 based on the body diameter and inflow velocity. In spite of the large inclination angle, the cylinder exhibits regular in-line and cross-flow vibrations excited by the flow through the lock-in mechanism, i.e. synchronization of body motion and vortex formation. A profound reconfiguration of the wake is observed compared with the stationary body case. The vortex-induced vibrations are found to occur under parallel, but also oblique vortex shedding where the spanwise wavenumbers of the wake and structural response coincide. The shedding angle and frequency increase with the spanwise wavenumber. The cylinder vibrations and fluid forces present a persistent spanwise asymmetry which relates to the asymmetry of the local current relative to the body axis, owing to its in-line bending. In particular, the asymmetrical trend of flow–body energy transfer results in a monotonic orientation of the structural waves. Clockwise and counter-clockwise figure eight orbits of the body alternate along the span, but the latter are found to be more favourable to structure excitation. Additional simulations at normal incidence highlight a dramatic deviation from the independence principle, which states that the system behaviour is essentially driven by the normal component of the inflow velocity. PMID:25512586

Investigating Morphological Stability of Faceted Interfaces with Axial Heat Processing (AHP) Technique

NASA Technical Reports Server (NTRS)

Abbaschian, Reza; Balikci, Ercan; Deal, Andrew; Gonik, Michael; Golyshev, Viladimir D.; Leonardi, Eddie; deVahlDavis, G.; Chen, P. Y. P.; Timchenko, V.

2003-01-01

Successful processing of homogeneous semiconductor single crystals from their melts depends strongly on precise control of thermal and fluid flow conditions near the solid/liquid interface. In this project, we utilize a novel crystal growth technique called Axial Heat Processing (AHP) that uses a baffle, positioned inside the melt near the interface, to supply and/or conduct heat axially to the interface. The baffle, which may or may not have a heater encased in it, can promote more stable and planar growth as well as reduce buoyancy driven convection. The latter is because the baffle reduces the aspect ratio of the melt as it separates the melt into three sections, above the baffle, in the feed gap between the baffle and the crucible wall, and below the baffle between the baffle base and the interface. AHP also enables a close monitoring and/or control of thermal boundaries near the solid/liquid interface during crystal growth by means of thermocouples placed in the baffle. The interface is kept planar when a heating element in the baffle is used. However, a proper choice of melt height is necessary to keep the interface planar when using the baffle without a heater. This study addresses the influence of melt height and growth velocity on the segregation profile of AHP-grown Sb doped Ge single crystals.

Enhancing sedimentation by improving flow conditions using parallel retrofit baffles.

PubMed

He, Cheng; Scott, Eric; Rochfort, Quintin

2015-09-01

In this study, placing parallel-connected baffles in the vicinity of the inlet was proposed to improve hydraulic conditions for enhancing TSS (total suspended solids) removal. The purpose of the retrofit baffle design is to divide the large and fast inflow into smaller and slower flows to increase flow uniformity. This avoids short-circuiting and increases residence time in the sedimentation basin. The newly proposed parallel-connected baffle configuration was assessed in the laboratory by comparing its TSS removal performance and the optimal flow residence time with those from the widely used series-connected baffles. The experimental results showed that the parallel-connected baffles outperformed the series-connected baffles because it could disperse flow faster and in less space by splitting the large inflow into many small branches instead of solely depending on flow internal friction over a longer flow path, as was the case under the series-connected baffles. Being able to dampen faster flow before entering the sedimentation basin is critical to reducing the possibility of disturbing any settled particles, especially under high inflow conditions. Also, for a large sedimentation basin, it may be more economically feasible to deploy the proposed parallel retrofit baffle in the vicinity of the inlet than series-connected baffles throughout the entire settling basin. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Optical Coating Performance for Heat Reflectors of the JWST-ISIM Electronic Component

NASA Technical Reports Server (NTRS)

Rashford, Robert A.; Perrygo, Charles M.; Garrison, Matthew B.; White, Bryant K.; Threat, Felix T.; Quijada, Manuel A.; Jeans, James W.; Huber, Frank K.; Bousquet, Robert R.; Shaw, Dave

2011-01-01

A document discusses a thermal radiator design consisting of lightweight composite materials and low-emittance metal coatings for use on the James Webb Space Telescope (JWST) structure. The structure will have a Thermal Subsystem unit to provide passive cooling to the Integrated Science Instrument Module (ISIM) control electronics. The ISIM, in the JWST observatory, is the platform that provides the mounting surfaces for the instrument control electronics. Dissipating the control electronic generated-heat away from JWST is of paramount importance so that the spacecraft s own heat does not interfere with the infrared-light gathering of distant cosmic sources. The need to have lateral control in the emission direction of the IEC (ISIM Electronics Compartment) radiators led to the development of a directional baffle design that uses multiple curved mirrorlike surfaces. This concept started out from the so-called Winston non-imaging optical concentrators that use opposing parabolic reflector surfaces, where each parabola has its focus at the opposite edge of the exit aperture. For this reason they are often known as compound parabolic concentrators or CPCs. This radiator system with the circular section was chosen for the IEC reflectors because it offers two advantages over other designs. The first is that the area of the reflector strips for a given radiator area is less, which results in a lower mass baffle assembly. Secondly, the fraction of energy emitted by the radiator strips and subsequently reflected by the baffle is less. These fewer reflections reduced the amount of energy that is absorbed and eventually re-emitted, typically in a direction outside the design emission range angle. A baffle frame holds the mirrors in position above a radiator panel on the IEC. Together, these will direct the majority of the heat from the IEC above the sunshield away towards empty space.

Narrow Angle Wide Spectral Range Radiometer Design FEANICS/REEFS Radiometer Design Report

NASA Technical Reports Server (NTRS)

Camperchioli, William

2005-01-01

A critical measurement for the Radiative Enhancement Effects on Flame Spread (REEFS) microgravity combustion experiment is the net radiative flux emitted from the gases and from the solid fuel bed. These quantities are measured using a set of narrow angle, wide spectral range radiometers. The radiometers are required to have an angular field of view of 1.2 degrees and measure over the spectral range of 0.6 to 30 microns, which presents a challenging design effort. This report details the design of this radiometer system including field of view, radiometer response, radiometric calculations, temperature effects, error sources, baffling and amplifiers. This report presents some radiometer specific data but does not present any REEFS experiment data.

Violent transient sloshing-wave interaction with a baffle in a three-dimensional numerical tank

NASA Astrophysics Data System (ADS)

Xue, Mi-An; Zheng, Jinhai; Lin, Pengzhi; Xiao, Zhong

2017-08-01

A finite difference model for solving Navier Stokes equations with turbulence taken into account is used to investigate viscous liquid sloshing-wave interaction with baffles in a tank. The volume-of-fluid and virtual boundary force methods are employed to simulate free surface flow interaction with structures. A liquid sloshing experimental apparatus was established to evaluate the accuracy of the proposed model, as well as to study nonlinear sloshing in a prismatic tank with the baffles. Damping effects of sloshing in a rectangular tank with bottom-mounted vertical baffles and vertical baffles touching the free surface are studied numerically and experimentally. Good agreement is obtained between the present numerical results and experimental data. The numerical results match well with the current experimental data for strong nonlinear sloshing with large free surface slopes. The reduction in sloshing-wave elevation and impact pressure induced by the bottom-mounted vertical baffle and the vertical baffle touching the free surface is estimated by varying the external excitation frequency and the location and height of the vertical baffle under horizontal excitation.

High prevalence of baffle leaks in adults after atrial switch operations for transposition of the great arteries.

PubMed

De Pasquale, Gabriella; Bonassin Tempesta, Francesca; Lopes, Bruno Santos; Babic, Daniela; Oxenius, Angela; Seeliger, Theresa; Gruner, Christiane; Tanner, Felix C; Biaggi, Patric; Attenhofer Jost, Christine; Greutmann, Matthias

2017-05-01

To determine the prevalence of baffle leaks in adults after atrial switch operations for transposition of the great arteries, as these may predispose to paradoxical embolic events, particularly in patients with transvenous pacemaker or defibrillator leads. We routinely perform contrast echocardiography with agitated saline in all patients after atrial switch operations. For this study, we analysed patients who had saline contrast echocardiography between 2010 and 2012. The presence of baffle leaks and the severity of right-to-left shunting were assessed. We compared baseline characteristics and oxygen saturation at rest and during exercise between patients with and without baffle leaks. A total of 65 patients (56 Senning and 9 Mustard repair) without previously known baffle leaks were included (mean age 32 ± 8 years, 77% males). Right-to-left shunting was identified in 42 patients (65%) and occurred without provocation manoeuvres in 88%. There were no differences in baseline characteristics, echocardiographic findings, or exercise capacity between patients with and without baffle leaks, except for lower oxygen saturation at peak exercise in those with baffle leaks (29% had oxygen saturations below 90% at peak exercise compared to none without baffle leaks, P = 0.011). Four patients with baffle leaks had previous implantation of transvenous pacemaker leads; one of them had suffered a stroke. Two other patients with baffle leaks had a history of potential embolic stroke. Because of the high prevalence of baffle leaks in adults after atrial switch operations, we propose routine screening with agitated saline contrast, particularly prior to implantation of transvenous pacemaker or defibrillator leads. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Optical and mechanical design and characterization of the new baffle for the 2.4-m Thai National Telescope

NASA Astrophysics Data System (ADS)

Buisset, Christophe; Prasit, Apirat; Lépine, Thierry; Poshyajinda, Saran

2015-09-01

The first astronomical images obtained at the 2.4 m Thai National Telescope (TNT) during observations in bright moon conditions were contaminated by high levels of light scattered by the telescope structure. We identified that the origins of this scattered light were the M3 folding mirror baffle and the tube placed inside the fork between the M3 and the M4 mirrors. We thus decided to design and install a new baffle. In a first step, we calculated the optical and mechanical inputs needed to define the baffle optical design. These inputs were: the maximum length of the baffle, the maximum dimensions of the vanes and the incident beam diameter between M3 and M4 mirrors. In a second step, we defined the number, the position and the diameter of the vanes to remove the critical objects from the detector's FOV by using a targeted method. Then, we verified that the critical objects were moved away from the detector's view. In a third step, we designed and manufactured the baffle. The mechanical design is made of 21 sections (1 section for each vane) and comprises an innovative mechanism for the adjustment of the baffle position. The baffle installation and adjustment is performed in less than 20 minutes by 2 operators. In a fourth step, we installed and characterized the baffle by using a pinhole camera. We quantified the performance improvement and we identified the baffle areas at the origin of the residual stray light signal. Finally, we performed targeted on-sky observations to test the baffle in real conditions.

A star tracker insensitive to stray light generated by radiation sources close to the field of view

NASA Astrophysics Data System (ADS)

Romoli, A.; Gambicorti, L.; Simonetti, F.; Zuccaro Marchi, A.

2017-11-01

Aim of this work is to propose an innovative star tracker, practically insensitive to the radiation coming from the sun or from other strong planetary sources out of (but near) the Field of View. These sources need to be stopped in some way. The classical solution to reject the unwanted radiation is to place a shadow (or baffle) before the star tracker objective. The shadow size depends on the Field of View and on the minimum angle subtended by the source (i.e. the sun) with respect to the optical axis of the star tracker. The lower is this angle the larger is the shadow. Requests for star trackers able to work with the sun as close as possible to the Field of View are increasing, due to the need of maximum mission flexibility. The innovation of this proposed star tracker is conceived by using spatial filtering with a concept complementary to that of coronagraph for sun corona observation, allowing to drastically reduce the size of the shadow. It can also work close to antennas and other part of the platform, which, when illuminated by the sun, become secondary sources capable to blind the star tracker. This kind of accommodation offers three main advantages: no cumbersome shadows (baffle), maximum flexibility in terms of mission profile, less platform location constraints. This new star sensor concept, dated 2007, is now patent pending. Galileo Avionica (now Selex Galileo) is the owner of the patent.

Evaluation of nutrient removal efficiency and microbial enzyme activity in a baffled subsurface-flow constructed wetland system

Treesearch

Lihua Cui; Ying Ouyang; Wenjie Gu; Weozhi Yang; Qiaoling Xu

2013-01-01

In this study, the enzyme activities and their relationships to domestic wastewater purification are investigated in four different types of subsurface-flow constructed wetlands (CWs), namely the traditional horizontal subsurface-flow, horizontal baffled subsurface-flow, vertical baffled subsurface-flow, and composite baffled subsurface-flow CWs. Results showed that...

Liquid management in low gravity using baffled rotating containers

NASA Technical Reports Server (NTRS)

Gans, R. F.

1985-01-01

Possible static configurations of liquids in rotating cylindrical containers with baffles evenly spaced in the axial direction are found. The force balance is among surface tension, centrifugal force and gravity. Two instabilities are found in this parameter space: type 1 is the inability of the liquid to form an interface attached to the baffles; type 2 is the inability for multi-baffled configurations to sustain interfaces between each pair of baffles. The type 1 analysis is confirmed through laboratory based equipment. Applications to orbiting containers are discussed.

Liquid management in low gravity using baffled rotating containers

NASA Technical Reports Server (NTRS)

Gans, R. F.

1984-01-01

Possible static configurations of liquids in rotating cylindrical containers with baffles evenly spaced in the axial direction are found. The force balance is among surface tension, centrifugal force and gravity. Two instabilities are found in this parameter space: type 1 is the inability of the liquid to form an interface attached to the baffles; type 2 is the inability for multi-baffled configurations to sustain interfaces between each pair of baffles. The type 1 analysis is confirmed through laboratory based equipment. Applications to orbiting containers are discussed.

Direction-of-arrival estimation for a uniform circular acoustic vector-sensor array mounted around a cylindrical baffle

NASA Astrophysics Data System (ADS)

Yang, DeSen; Zhu, ZhongRui

2012-12-01

This work investigates the direction-of-arrival (DOA) estimation for a uniform circular acoustic Vector-Sensor Array (UCAVSA) mounted around a cylindrical baffle. The total pressure field and the total particle velocity field near the surface of the cylindrical baffle are analyzed theoretically by applying the method of spatial Fourier transform. Then the so-called modal vector-sensor array signal processing algorithm, which is based on the decomposed wavefield representations, for the UCAVSA mounted around the cylindrical baffle is proposed. Simulation and experimental results show that the UCAVSA mounted around the cylindrical baffle has distinct advantages over the same manifold of traditional uniform circular pressure-sensor array (UCPSA). It is pointed out that the acoustic Vector-Sensor (AVS) could be used under the condition of the cylindrical baffle and that the UCAVSA mounted around the cylindrical baffle could also combine the anti-noise performance of the AVS with spatial resolution performance of array system by means of modal vector-sensor array signal processing algorithms.

Investigation of Damping Physics and CFD Tool Validation for Simulation of Baffled Tanks at Variable Slosh Amplitude

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeffrey

2016-01-01

To meet the flight control damping requirement, baffles of various configurations have been devised to increase the natural viscous damping and decrease the magnitude of the slosh forces and torques. In the design of slosh baffles, the most widely used damping equation is the one derived by Miles, which is based on the experiments of Keulegan and Carpenter. This equation has been used in predicting damping of the baffled tanks in different diameters ranging from 12 to 112 inches. The analytical expression of Miles equation is easy to use, especially in the design of complex baffle system. Previous investigations revealed that some experiments had shown good agreements with the prediction method of Miles, whereas other experiments have shown significant deviations. For example, damping from Miles equation differs from experimental measurements by as much as 100 percent over a range of tank diameters from 12 to 112 inches, oscillation amplitudes from 0.1 to 1.5 baffle widths, and baffle depths of 0.3 to 0.5 tank radius. Previously, much of this difference has been attributed to experimental scatter. A systematical study is needed to understand the damping physics of baffled tanks, to identify the difference between Miles equation and experimental measurement, and to develop new semi-empirical relations to better represent the real damping physics. The approach of this study is to use CFD technology to shed light on the damping mechanisms of a baffled tank. First, a 1-D Navier-Stokes equation representing different length scales and time scales in the baffle damping physics is developed and analyzed. A well validated CFD solver, developed at NASA MSFC, Loci-STREAM-VOF, is applied to study vorticity field around the baffle and around the fluid interface to highlight the dissipation mechanisms at different slosh amplitudes. Previous measurement data are then used to validate the CFD damping results. The study found several critical parameters controlling fluid damping from a baffle: local slosh amplitude to baffle thickness (A/t), surface liquid depth to tank radius (h/R), local slosh amplitude to baffle width (A/W); and non-dimensional slosh frequency. The simulation highlights three significant damping regimes where different mechanisms dominate. The study proves that the previously found discrepancies between Miles equation and experimental measurement are not due to the measurement scatter, but rather due to different damping mechanisms at various slosh amplitudes. The limitations on the use of Miles equation are discussed based on the flow regime.

Effect of baffle size and orientation on lateral sloshing of partially filled containers: a numerical study

NASA Astrophysics Data System (ADS)

Ali, Sajid; Kamran, Muhammad Ali; Khan, Sikandar

2017-11-01

The fluid sloshing in partially filled road tankers has significantly increased the number of road accidents for the last few decades. Significant research is needed to investigate and to come up with optimum baffles designs that can help to increase the rollover stability of the partially filled tankers. In this investigation, a detailed analysis of the anti-slosh effectiveness of different baffle configurations is presented. This investigation extends the already available studies in the literature by introducing new modified rectangular tank's shapes that correspond to maximum rollover stability as compared to the already available standard tank designs. The various baffles configurations that are analysed in this study are horizontal, vertical, vertical-horizontal and diagonal. In the current study, numerical investigations are performed for rectangular, elliptical and circular tank shapes. Lateral sloshing, caused by constant radius turn manoeuvre, was simulated numerically using the volume-of-fluid method, and effect of the different baffle configurations was analysed. The effect of tank fill levels on sloshing measured in terms of horizontal force and pressure moments is also reported for with and without baffles configurations. Vertical baffles were the most effective at reducing sloshing in modified rectangular tanks, whereas a combination of horizontal and vertical baffles gave better results for the circular and elliptical tanks geometries.

Baffling or Baffled: Improve Your Acoustics.

ERIC Educational Resources Information Center

Abdoo, Frank B.

1981-01-01

Presents techniques for evaluating the acoustics (reverberation time, and standing waves and resonance phenomena) of a band performance room. Gives instructions for building and placing inexpensive baffles (free-standing, portable sound barriers) to correct room defects. (SJL)

Increasing thermal efficiency of solar flat plate collectors

NASA Astrophysics Data System (ADS)

Pona, J.

A study of methods to increase the efficiency of heat transfer in flat plate solar collectors is presented. In order to increase the heat transfer from the absorber plate to the working fluid inside the tubes, turbulent flow was induced by installing baffles within the tubes. The installation of the baffles resulted in a 7 to 12% increase in collector efficiency. Experiments were run on both 1 sq ft and 2 sq ft collectors each fitted with either slotted baffles or tubular baffles. A computer program was run comparing the baffled collector to the standard collector. The results obtained from the computer show that the baffled collectors have a 2.7% increase in life cycle cost (LCC) savings and a 3.6% increase in net cash flow for use in domestic hot water systems, and even greater increases when used in solar heating systems.

Tree crickets optimize the acoustics of baffles to exaggerate their mate-attraction signal.

PubMed

Mhatre, Natasha; Malkin, Robert; Deb, Rittik; Balakrishnan, Rohini; Robert, Daniel

2017-12-11

Object manufacture in insects is typically inherited, and believed to be highly stereotyped. Optimization, the ability to select the functionally best material and modify it appropriately for a specific function, implies flexibility and is usually thought to be incompatible with inherited behaviour. Here, we show that tree-crickets optimize acoustic baffles, objects that are used to increase the effective loudness of mate-attraction calls. We quantified the acoustic efficiency of all baffles within the naturally feasible design space using finite-element modelling and found that design affects efficiency significantly. We tested the baffle-making behaviour of tree crickets in a series of experimental contexts. We found that given the opportunity, tree crickets optimised baffle acoustics; they selected the best sized object and modified it appropriately to make a near optimal baffle. Surprisingly, optimization could be achieved in a single attempt, and is likely to be achieved through an inherited yet highly accurate behavioural heuristic.

APPARATUS FOR CONDENSATION AND SUBLIMATION

DOEpatents

Schmidt, R.J.; Fuis, F. Jr.

1958-10-01

An apparatus is presented for the sublimation and condensation of uranium compounds in order to obtain an improved crystalline structure of this material. The apparatus comprises a vaporizing chamber and condensing structure connected thereto. There condenser is fitted with a removable liner having a demountable baffle attached to the liner by means of brackets and a removable pin. The baffle is of spiral cross-section and is provided with cooling coils disposed between the surfaces of the baffle for circulation of a temperature controlling liquid within the baffle. The cooling coll provides for controlllng the temperature of the baffle to insure formatlon of a satisfactory condensate, and the removable liner facilitates the removal of condensate formed during tbe sublimation process.

Molten core retention assembly

DOEpatents

Lampe, Robert F.

1976-06-22

Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical, imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods.

Large Angle Reorientation of a Solar Sail Using Gimballed Mass Control

NASA Astrophysics Data System (ADS)

Sperber, E.; Fu, B.; Eke, F. O.

2016-06-01

This paper proposes a control strategy for the large angle reorientation of a solar sail equipped with a gimballed mass. The algorithm consists of a first stage that manipulates the gimbal angle in order to minimize the attitude error about a single principal axis. Once certain termination conditions are reached, a regulator is employed that selects a single gimbal angle for minimizing both the residual attitude error concomitantly with the body rate. Because the force due to the specular reflection of radiation is always directed along a reflector's surface normal, this form of thrust vector control cannot generate torques about an axis normal to the plane of the sail. Thus, in order to achieve three-axis control authority a 1-2-1 or 2-1-2 sequence of rotations about principal axes is performed. The control algorithm is implemented directly in-line with the nonlinear equations of motion and key performance characteristics are identified.

An efficient micromixer based on multidirectional vortices due to baffles and channel curvature.

PubMed

Tsai, Rei-Tang; Wu, Chih-Yang

2011-02-16

An efficient planar micromixer based on multidirectional vortices in a curved channel with radial baffles is proposed and examined in this work. The curvature of the microchannel and the radial baffles induce vortices in different directions. The multidirectional vortices and the converging-diverging flow caused by the baffles contribute together to the enhancement of mixing. The micromixer is fabricated with polydimethylsiloxane by a single planar microlithography process and the mixing behaviors are observed by a confocal spectral microscope imaging system to validate the simulation obtained by a commercial code. The simulation and experimental results are in reasonable agreement. The concentration distributions and flow patterns obtained reveal the following trends. (i) The mixing efficiency of the basic C-shaped micromixer with the first baffle attached to the internal cylinder and the second attached to the external cylinder is better than that of the C-shaped micromixer with inverted arrangement of baffles. (ii) When the radius of the curved channel and the width of the passage between the baffle and the cylindrical wall are small enough and the Reynolds number (Re) is large enough, an extra separation vortex develops in the downstream of the second baffle. This phenomenon is one of the reasons of trend (i). (iii) A micromixer consisting of a few basic C-shaped micromixers connected by straight channels may generate a high degree of mixing for the case with a large Re.

Cross-section perimeter is a suitable parameter to describe the effects of different baffle geometries in shaken microtiter plates

PubMed Central

2014-01-01

Background Biotechnological screening processes are performed since more than 8 decades in small scale shaken bioreactors like shake flasks or microtiter plates. One of the major issues of such reactors is the sufficient oxygen supply of suspended microorganisms. Oxygen transfer into the bulk liquid can in general be increased by introducing suitable baffles at the reactor wall. However, a comprehensive and systematic characterization of baffled shaken bioreactors has never been carried out so far. Baffles often differ in number, size and shape. The exact geometry of baffles in glass lab ware like shake flasks is very difficult to reproduce from piece to piece due to the hard to control flow behavior of molten glass during manufacturing. Thus, reproducibility of the maximum oxygen transfer capacity in such baffled shake flasks is hardly given. Results As a first step to systematically elucidate the general effect of different baffle geometries on shaken bioreactor performance, the maximum oxygen transfer capacity (OTRmax) in baffled 48-well microtiter plates as shaken model reactor was characterized. This type of bioreactor made of plastic material was chosen, as the exact geometry of the baffles can be fabricated by highly reproducible laser cutting. As a result, thirty different geometries were investigated regarding their maximum oxygen transfer capacity (OTRmax) and liquid distribution during shaking. The relative perimeter of the cross-section area as new fundamental geometric key parameter is introduced. An empirical correlation for the OTRmax as function of the relative perimeter, shaking frequency and filling volume is derived. For the first time, this correlation allows a systematic description of the maximum oxygen transfer capacity in baffled microtiter plates. Conclusions Calculated and experimentally determined OTRmax values agree within ± 30% accuracy. Furthermore, undesired out-of-phase operating conditions can be identified by using the relative perimeter as key parameter. Finally, an optimum well geometry characterized by an increased perimeter of 10% compared to the unbaffled round geometry is identified. This study may also assist to comprehensively describe and optimize the baffles of shake flasks in future. PMID:25093039

Geometric correction method for 3d in-line X-ray phase contrast image reconstruction

PubMed Central

2014-01-01

Background Mechanical system with imperfect or misalignment of X-ray phase contrast imaging (XPCI) components causes projection data misplaced, and thus result in the reconstructed slice images of computed tomography (CT) blurred or with edge artifacts. So the features of biological microstructures to be investigated are destroyed unexpectedly, and the spatial resolution of XPCI image is decreased. It makes data correction an essential pre-processing step for CT reconstruction of XPCI. Methods To remove unexpected blurs and edge artifacts, a mathematics model for in-line XPCI is built by considering primary geometric parameters which include a rotation angle and a shift variant in this paper. Optimal geometric parameters are achieved by finding the solution of a maximization problem. And an iterative approach is employed to solve the maximization problem by using a two-step scheme which includes performing a composite geometric transformation and then following a linear regression process. After applying the geometric transformation with optimal parameters to projection data, standard filtered back-projection algorithm is used to reconstruct CT slice images. Results Numerical experiments were carried out on both synthetic and real in-line XPCI datasets. Experimental results demonstrate that the proposed method improves CT image quality by removing both blurring and edge artifacts at the same time compared to existing correction methods. Conclusions The method proposed in this paper provides an effective projection data correction scheme and significantly improves the image quality by removing both blurring and edge artifacts at the same time for in-line XPCI. It is easy to implement and can also be extended to other XPCI techniques. PMID:25069768

In-line phase retarder and polarimeter for conversion of linear to circular polarization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kortright, J.B.; Smith, N.V.; Denlinger, J.D.

1997-04-01

An in-line polarimeter including phase retarder and linear polarizer was designed and commissioned on undulator beamline 7.0 for the purpose of converting linear to circular polarization for experiments downstream. In commissioning studies, Mo/Si multilayers at 95 eV were used both as the upstream, freestanding phase retarder and the downstream linear polarized. The polarization properties of the phase retarder were characterized by direct polarimetry and by collecting MCD spectra in photoemission from Gd and other magnetic surfaces. The resonant birefringence of transmission multilayers results from differing distributions of s- and p-component wave fields in the multilayer when operating near a structuralmore » (Bragg) interference condition. The resulting phase retardation is especially strong when the interference is at or near the Brewster angle, which is roughly 45{degrees} in the EUV and soft x-ray ranges.« less

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.

Extension of Miles Equation for Ring Baffle Damping Predictions to Small Slosh Amplitudes and Large Baffle Widths

NASA Technical Reports Server (NTRS)

West, Jeff; Yang, H. Q.; Brodnick, Jacob; Sansone, Marco; Westra, Douglas

2016-01-01

The Miles equation has long been used to predict slosh damping in liquid propellant tanks due to ring baffles. The original work by Miles identifies defined limits to its range of application. Recent evaluations of the Space Launch System identified that the Core Stage baffle designs resulted in violating the limits of the application of the Miles equation. This paper describes the work conducted by NASA/MSFC to develop methods to predict slosh damping from ring baffles for conditions for which Miles equation is not applicable. For asymptotically small slosh amplitudes or conversely large baffle widths, an asymptotic expression for slosh damping was developed and calibrated using historical experimental sub-scale slosh damping data. For the parameter space that lies between region of applicability of the asymptotic expression and the Miles equation, Computational Fluid Dynamics simulations of slosh damping were used to develop an expression for slosh damping. The combined multi-regime slosh prediction methodology is shown to be smooth at regime boundaries and consistent with both sub-scale experimental slosh damping data and the results of validated Computational Fluid Dynamics predictions of slosh damping due to ring baffles.

Experimentally enhanced model-based deconvolution of propagation-based phase-contrast data

NASA Astrophysics Data System (ADS)

Pichotka, M.; Palma, K.; Hasn, S.; Jakubek, J.; Vavrik, D.

2016-12-01

In recent years phase-contrast has become a much investigated modality in radiographic imaging. The radiographic setups employed in phase-contrast imaging are typically rather costly and complex, e.g. high performance Talbot-Laue interferometers operated at synchrotron light sources. In-line phase-contrast imaging states the most pedestrian approach towards phase-contrast enhancement. Utilizing small angle deflection within the imaged sample and the entailed interference of the deflected and un-deflected beam during spatial propagation, in-line phase-contrast imaging only requires a well collimated X-ray source with a high contrast & high resolution detector. Employing high magnification the above conditions are intrinsically fulfilled in cone-beam micro-tomography. As opposed of 2D imaging, where contrast enhancement is generally considered beneficial, in tomographic modalities the in-line phase-contrast effect can be quite a nuisance since it renders the inverse problem posed by tomographic reconstruction inconsistent, thus causing reconstruction artifacts. We present an experimentally enhanced model-based approach to disentangle absorption and in-line phase-contrast. The approach employs comparison of transmission data to a system model computed iteratively on-line. By comparison of the forward model to absorption data acquired in continuous rotation strong local deviations of the data residual are successively identified as likely candidates for in-line phase-contrast. By inducing minimal vibrations (few mrad) to the sample around the peaks of such deviations the transmission signal can be decomposed into a constant absorptive fraction and an oscillating signal caused by phase-contrast which again allows to generate separate maps for absorption and phase-contrast. The contributions of phase-contrast and the corresponding artifacts are subsequently removed from the tomographic dataset. In principle, if a 3D handling of the sample is available, this method also allows to track discontinuities throughout the volume and therefore states a powerful tool in 3D defectoscopy.

Floating baffle to improve efficiency of liquid transfer from tanks

NASA Technical Reports Server (NTRS)

Howard, F. S. (Inventor)

1973-01-01

A floating baffle is described which rides up and down on a vertical shaft over a drain in a tank as the liquid level within the tank varies. When the baffle is in the raised position, the liquid is allowed to flow out of the drain at an unrestricted rate. When the baffle is in the lowered position, pull-through of air or gas that is above the liquid is presented, which would interfere and reduce the flow of liquid from the tank.

Effect of the Inclination of Baffles on the Power Consumption and Fluid Flows in a Vessel Stirred by a Rushton Turbine

NASA Astrophysics Data System (ADS)

Kamla, Youcef; Bouzit, Mohamed; Ameur, Houari; Arab, Mohammed Ilies; Hadjeb, Abdessalam

2017-07-01

The role of baffles in mechanically stirred tanks is to promote the stability of power drawn by the impeller and to avoid the fluid swirling, thus enhancing mixing. The present paper numerically investigates the baffles effects in a vessel stirred by a Rushton turbine. The geometric factor of interest is the baffle inclination which is varying between 25°, 32.5°, 45°, 70° and 90° at different impeller rotational speeds. The impeller rotational direction has also been varied. The vortex size and power consumption were evaluated for each geometrical configuration. It was found that the best configuration is the baffle inclination by α = 70° at a negative angular velocity.

Liquid inflow to a baffled cylindrical tank during weightlessness

NASA Technical Reports Server (NTRS)

Staskus, J. V.

1972-01-01

An experimental investigation was conducted in which the behavior of liquid inflow to a cylindrical tank containing inlet baffles was observed during weightlessness. A single tank radius (2 cm), inlet radius (0.2 cm), and liquid (ethanol)were used. The inlet end of the tank was hemispherical with a 30 deg convergent inlet. All the baffle configurations tested were cylindrically symmetric and mounted coaxially with the tank within the hemispherical end. Both stable and unstable inflow behavior were observed using each baffle. It was found that, depending on which of the baffles was used, the critical inflow velocity at which a transition to unstable inflow began was from 2.5 to 12 times greater than the corresponding velocity in an unbaffled tank.

Thermal Test Verification of Emission Control through Directional Baffles for the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Garrison, Matthew; Rashford, Robert; Switzer, Timothy; Shaw, David; White, Bryant; Lynch, Michael; Huber, Frank; Bachtell, Neal

2009-01-01

The thermal performance of NASA s planned James Webb Space Telescope is highly reliant on a collection of directional baffles that are part of the Integrated Science Instrument Module Electronics Compartment. In order to verify the performance of the baffle concept, two test assemblies were recently fabricated and tested at the Goddard Space Flight Center. The centerpiece of the testing was a fixture that used bolometers to measure the emission field through the baffles while the radiator panels and baffles ran a flight-like temperature. Although not all test goals were able to be met due to facility malfunctions, the test was able to prove the design viability enough to gain approval to begin manufacturing the flight article.

Tree crickets optimize the acoustics of baffles to exaggerate their mate-attraction signal

PubMed Central

Balakrishnan, Rohini; Robert, Daniel

2017-01-01

Object manufacture in insects is typically inherited, and believed to be highly stereotyped. Optimization, the ability to select the functionally best material and modify it appropriately for a specific function, implies flexibility and is usually thought to be incompatible with inherited behaviour. Here, we show that tree-crickets optimize acoustic baffles, objects that are used to increase the effective loudness of mate-attraction calls. We quantified the acoustic efficiency of all baffles within the naturally feasible design space using finite-element modelling and found that design affects efficiency significantly. We tested the baffle-making behaviour of tree crickets in a series of experimental contexts. We found that given the opportunity, tree crickets optimised baffle acoustics; they selected the best sized object and modified it appropriately to make a near optimal baffle. Surprisingly, optimization could be achieved in a single attempt, and is likely to be achieved through an inherited yet highly accurate behavioural heuristic. PMID:29227246

An efficient micromixer based on multidirectional vortices due to baffles and channel curvature

PubMed Central

Tsai, Rei-Tang; Wu, Chih-Yang

2011-01-01

An efficient planar micromixer based on multidirectional vortices in a curved channel with radial baffles is proposed and examined in this work. The curvature of the microchannel and the radial baffles induce vortices in different directions. The multidirectional vortices and the converging-diverging flow caused by the baffles contribute together to the enhancement of mixing. The micromixer is fabricated with polydimethylsiloxane by a single planar microlithography process and the mixing behaviors are observed by a confocal spectral microscope imaging system to validate the simulation obtained by a commercial code. The simulation and experimental results are in reasonable agreement. The concentration distributions and flow patterns obtained reveal the following trends. (i) The mixing efficiency of the basic C-shaped micromixer with the first baffle attached to the internal cylinder and the second attached to the external cylinder is better than that of the C-shaped micromixer with inverted arrangement of baffles. (ii) When the radius of the curved channel and the width of the passage between the baffle and the cylindrical wall are small enough and the Reynolds number (Re) is large enough, an extra separation vortex develops in the downstream of the second baffle. This phenomenon is one of the reasons of trend (i). (iii) A micromixer consisting of a few basic C-shaped micromixers connected by straight channels may generate a high degree of mixing for the case with a large Re. PMID:21403848

Constitutive equations of a tensorial model for strain-induced damage of metals based on three invariants

NASA Astrophysics Data System (ADS)

Tutyshkin, Nikolai D.; Lofink, Paul; Müller, Wolfgang H.; Wille, Ralf; Stahn, Oliver

2017-01-01

On the basis of the physical concepts of void formation, nucleation, and growth, generalized constitutive equations are formulated for a tensorial model of plastic damage in metals based on three invariants. The multiplicative decomposition of the metric transformation tensor and a thermodynamically consistent formulation of constitutive relations leads to a symmetric second-order damage tensor with a clear physical meaning. Its first invariant determines the damage related to plastic dilatation of the material due to growth of the voids. The second invariant of the deviatoric damage tensor is related to the change in void shape. The third invariant of the deviatoric tensor describes the impact of the stress state on damage (Lode angle), including the effect of rotating the principal axes of the stress tensor (Lode angle change). The introduction of three measures with related physical meaning allows for the description of kinetic processes of strain-induced damage with an equivalent parameter in a three-dimensional vector space, including the critical condition of ductile failure. Calculations were performed by using experimentally determined material functions for plastic dilatation and deviatoric strain at the mesoscale, as well as three-dimensional graphs for plastic damage of steel DC01. The constitutive parameter was determined from tests in tension, compression, and shear by using scanning electron microscopy, which allowed to vary the Lode angle over the full range of its values [InlineEquation not available: see fulltext.]. In order to construct the three-dimensional plastic damage curve for a range of triaxiality parameters -1 ≤ ST ≤ 1 and of Lode angles [InlineEquation not available: see fulltext.], we used our own, as well as systematized published experimental data. A comparison of calculations shows a significant effect of the third invariant (Lode angle) on equivalent damage. The measure of plastic damage, based on three invariants, can be useful for assessing the quality of metal mesostructure produced during metal forming processes. In many processes of metal sheet forming the material experiences, a non-proportional loading accompanied by rotating the principal axes of the stress tensor and a corresponding change of Lode angle.

Apparatus for leaching core material from clad nuclear fuel pin segments

DOEpatents

Yarbro, Orlan O.

1980-01-01

This invention relates to improved apparatus for counter-currently contacting liquids and solids to dissolve, or leach, a selected component of the solids while minimizing back-mixing of the liquid phase. The apparatus includes an elongated drum which is rotatable about its longitudinal axis in either direction and is partitioned radially into a solids-inlet/liquid-outlet compartment at one end, a solids-outlet/liquid-inlet compartment at its other end, and leaching compartments therebetween. The drum is designed to operate with its acid-inlet end elevated and with the longitudinal axis of the drum at an angle in the range of from about 3.degree. to 14.degree. to the horizontal. Each leaching compartment contains a chute assembly for advancing solids into the next compartment in the direction of solids flow when the drum is rotated in a selected direction. The chute assembly includes a solids-transfer baffle and a chute in the form of a slotted, skewed, conical frustum portion. When the drum is rotated in the direction opposite to that effecting solids transfer, the solids-transfer baffles continually separate and re-mix the solids and liquids in their respective compartments. The partitions defining the leaching compartments are formed with corresponding outer, annular, imperforate regions, each region extending inwardly from the partition rim to an annular array of perforations concentric with the rim. In each leaching compartment, the spacing between the rim and the perforations determines the depth of liquid at the liquid-outlet end of the compartment. The liquid input to the drum assembly flows continuously through the compartments, preventing back-mixing due to density differences, whereas backflow due to waves generated by the solids-transfer baffles is virtually eliminated because of the tilted orientation of the drum assembly.

Influence of Shading on Cooling Energy Demand

NASA Astrophysics Data System (ADS)

Rabczak, Sławomir; Bukowska, Maria; Proszak-Miąsik, Danuta; Nowak, Krzysztof

2017-10-01

The article presents an analysis of the building cooling load taking into account the variability of the factors affecting the size of the heat gains. In order to minimize the demand for cooling, the effect of shading elements installed on the outside on the windows and its effect on size of the cooling capacity of air conditioning system for the building has been estimated. Multivariate building cooling load calculations to determine the size of the reduction in cooling demand has derived. Determination of heat gain from the sun is laborious, but gives a result which reflects the influence of the surface transparent partitions, devices used as sunscreen and its location on the building envelope in relation to the world, as well as to the internal heat gains has great attention in obtained calculation. In this study, included in the balance sheet of solar heat gains are defined in three different shading of windows. Calculating the total demand cooling is made for variants assuming 0% shading baffles transparent, 50% shading baffles transparent external shutters at an angle of 45 °, 100% shading baffles transparent hours 12 from the N and E and from 12 from the S and W of the outer slat blinds. The calculation of the average hourly cooling load was taken into account the option assuming the hypothetical possibility of default by up to 10% of the time assumed the cooling season temperatures in the rooms. To reduce the consumption of electricity energy in the cooling system of the smallest variant identified the need for the power supply for the operation of the cooling system. Also assessed the financial benefits of the temporary default of comfort.

Solar glint suppression in compact planetary ultraviolet spectrographs

NASA Astrophysics Data System (ADS)

Davis, Michael W.; Cook, Jason C.; Grava, Cesare; Greathouse, Thomas K.; Gladstone, G. Randall; Retherford, Kurt D.

2015-08-01

Solar glint suppression is an important consideration in the design of compact photon-counting ultraviolet spectrographs. Southwest Research Institute developed the Lyman Alpha Mapping Project for the Lunar Reconnaissance Orbiter (launch in 2009), and the Ultraviolet Spectrograph on Juno (Juno-UVS, launch in 2011). Both of these compact spectrographs revealed minor solar glints in flight that did not appear in pre-launch analyses. These glints only appeared when their respective spacecraft were operating outside primary science mission parameters. Post-facto scattered light analysis verifies the geometries at which these glints occurred and why they were not caught during ground testing or nominal mission operations. The limitations of standard baffle design at near-grazing angles are discussed, as well as the importance of including surface scatter properties in standard stray light analyses when determining solar keep-out efficiency. In particular, the scattered light analysis of these two instruments shows that standard "one bounce" assumptions in baffle design are not always enough to prevent scattered sunlight from reaching the instrument focal plane. Future builds, such as JUICE-UVS, will implement improved scattered and stray light modeling early in the design phase to enhance capabilities in extended mission science phases, as well as optimize solar keep out volume.

A numerical study of a vertical solar air collector with obstacle

NASA Astrophysics Data System (ADS)

Moumeni, A.; Bouchekima, B.; Lati, M.

2016-07-01

Because of the lack of heat exchange obtained by a solar air between the fluid and the absorber, the introduction of obstacles arranged in rows overlapping in the ducts of these systems improves heat transfer. In this work, a numerical study using the finite volume methods is made to model the dynamic and thermal behavior of air flow in a vertical solar collector with baffles destined for integration in building. We search essentially to compare between three air collectors models with different inclined obstacles angle. The first kind with 90° shows a good performance energetic and turbulent.

Steady state modeling of large diameter crystal growth using baffles

NASA Technical Reports Server (NTRS)

Sahai, Vivek; Williamson, John; Overfelt, Tony

1991-01-01

Buoyancy driven flow in the crystal melt is one of the leading causes of segregation. Natural convection arises from the presence of thermal and/or solutal gradients in the melt and it is not possible to completely eliminate the convection even in the low gravity environment of space. This paper reports the results of computational modeling research that is being done in preparation for space-based experiments. The commercial finite element code FIDAP was used to simulate the steady convection of a gallium-doped germanium alloy in a Bridgman-Stockbarger furnace. In particular, the study examines the convection-suppressing benefits of inserting cylindrical baffles in the molten region to act as viscous dampers. These thin baffles are assumed to be inert and noncontaminating. The results from this study show the manner in which the streamlines, velocities, and temperature fields at various gravity levels are affected by the presence of baffles. The effects of changing both the number and position of the baffles are examined and the advantages and disadvantages of using baffles are considered.

Effects of structural parameters on fluid flow and mixing performance in a curved microchannel with gaps and baffles

NASA Astrophysics Data System (ADS)

Li, Jian; Xia, Guodong; Li, Yifan; Tian, Xinping

2013-07-01

We provide three-dimensional numerical simulations of mixing performance in a newly proposed micromixer with different structural parameters. The same amount of gaps and baffles are arranged along the curved channel within a certain distance. The effects of their structural parameters on mixing efficiency are presented, which include either the position and feature size of gaps and baffles, or the curvature radius of curved channel. The high efficiency mixing mechanism of the curved channel with gaps and baffles can attribute to the interaction of the increased contact area for premixed liquids, the jet and throttling effect over every unit of gap and baffle, the developing of the multidirectional vortices along the curved channel. The mixing index is sensitive to the width of the gaps and baffles for some Reynolds number ranges, but is not sensitive to the curvature radius of the curved channel. The characteristic of the pressure drop depending on Reynolds number is also investigated in order to keep an appropriate balance with mixing property.

Research on liquid sloshing performance in vane type tank under microgravity

NASA Astrophysics Data System (ADS)

Hu, Q.; Li, Y.; Liu, J. T.; Liang, J. Q.

2016-05-01

Propellant management device (PMD) in vane type tank mainly comprises of vane type structure parts, whose performance of restraining liquid sloshing should satisfy spacecraft requirements of high stabilization and fast orbital maneuver. Aiming at liquid sloshing performance in vane type tank under microgravity environment, gas-liquid flow model based on the volume of fluid (VOF) method was put forward, and via numerical simulation liquid sloshing performances of vane type PMD with anti-sloshing baffles and without anti-sloshing baffles in microgravity were analyzed and compared. Simulation results reveal that liquid sloshing performance of vane type PMD with anti-sloshing baffles is markedly superior vane type PMD without anti-sloshing baffles and the baffles make liquid surface become stable fast. Then by comparing between results of microgravity experiments and results of numerical simulations, they are very similar. According to present research, vane type PMD with antisloshing baffles has better effects on restraining liquid sloshing and is able to restrain observably propellant sloshing in tanks in order to satisfy spacecraft requirements of high stabilization and fast orbital maneuver.

Influence of a finite number of baffles on shell-and-tube heat exchanger performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shah, R.K.; Pignotti, A.

1997-01-01

In single-phase shell-and-tube heat exchangers, thermal performance prediction is customarily accomplished with an idealization that the number of baffles used is very large and can be assumed to approach infinity. Under this idealization, the temperature change within each baffle compartment is very small in comparison with the total temperature change of the shell fluid through the heat exchanger. Thus the shell fluid can be considered as uniform (perfectly mixed) at every cross section (in a direction normal to the shell axis). It is with this model that the mean temperature difference correction factor is normally derived for single-phase exchangers. Inmore » reality, a finite number of baffles are used, and the condition stated above can be achieved only partially. In this article, a comprehensive review is made and new results are derived where needed to assess the influence of a finite number of baffles on heat transfer performance for 1-1, 1-2, and 1-N TEMA E, 1-2 TEMA J, and 1-2 TEMA G and H single-phase shell-and-tube exchangers. It is shown that the number of baffles required to achieve the performance within about 2% of an exchanger with an infinite number of baffles varies with the type of exchanger and the performance parameters. The new results are presented in tabular form.« less

REACTOR SHIELD

DOEpatents

Wigner, E.P.; Ohlinger, L.E.; Young, G.J.; Weinberg, A.M.

1959-02-17

Radiation shield construction is described for a nuclear reactor. The shield is comprised of a plurality of steel plates arranged in parallel spaced relationship within a peripheral shell. Reactor coolant inlet tubes extend at right angles through the plates and baffles are arranged between the plates at right angles thereto and extend between the tubes to create a series of zigzag channels between the plates for the circulation of coolant fluid through the shield. The shield may be divided into two main sections; an inner section adjacent the reactor container and an outer section spaced therefrom. Coolant through the first section may be circulated at a faster rate than coolant circulated through the outer section since the area closest to the reactor container is at a higher temperature and is more radioactive. The two sections may have separate cooling systems to prevent the coolant in the outer section from mixing with the more contaminated coolant in the inner section.

Investigation of the effects of inlet shapes on fan noise radiation

NASA Technical Reports Server (NTRS)

Clark, T. L.; Slotboom, D. R.; Vaidya, P. G.

1981-01-01

The effect of inlet shape on forward radiated fan tone noise directivities was investigated under experimentally simplified zero flow conditions. Simulated fan tone noise was radiated to the far field through various shaped zero flow inlets. Baseline data were collected for the simplest baffled and unbaffled straight pipe inlets. These data compared well with prediction. The more general inlet shapes tested were the conical, circular, and exponential surfaces of revolution and an asymmetric inlet achieved by cutting a straight pipe inlet at an acute angle. Approximate theories were developed for these general shapes and some comparisons with data are presented. The conical and exponential shapes produced directivities that differed considerably from the baseline data while the circular shape produced directivities similar to the baseline data. The asymmetric inlet produced asymmetric directivities with significant reductions over the straight pipe data for some angles.

Stator hub treatment study

NASA Technical Reports Server (NTRS)

Wisler, D. C.; Hilvers, D. E.

1974-01-01

The results of an experimental research program to investigate the potential of improving compressor stall margin by the application of hub treatment are presented. Extensive tuft probing showed that the two-stage, 0.5 radius ratio compressor selected for the test was indeed hub critical. Circumferential groove and baffled wide blade angle slot hub treatments under the stators were tested. Performance measurements were made with total and static pressure probes, wall static pressure taps, flow angle measuring instrumentation and hot film anemometers. Stator hub treatment was not found to be effective in improving compressor stall margin by delaying the point of onset of rotating stall or in modifying compressor performance for any of the configurations tested. Extensive regions of separated flow were observed on the suction surface of the stators near the hub. However, the treatment did not delay the point where flow separation in the stator hub region becomes apparent.

Validity of Miles Equation in Predicting Propellant Slosh Damping in Baffled Tanks at Variable Slosh Amplitude

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeff

2018-01-01

Determination of slosh damping is a very challenging task as there is no analytical solution. The damping physics involves the vorticity dissipation which requires the full solution of the nonlinear Navier-Stokes equations. As a result, previous investigations were mainly carried out by extensive experiments. A systematical study is needed to understand the damping physics of baffled tanks, to identify the difference between the empirical Miles equation and experimental measurements, and to develop new semi-empirical relations to better represent the real damping physics. The approach of this study is to use Computational Fluid Dynamics (CFD) technology to shed light on the damping mechanisms of a baffled tank. First, a 1-D Navier-Stokes equation representing different length scales and time scales in the baffle damping physics is developed and analyzed. Loci-STREAM-VOF, a well validated CFD solver developed at NASA MSFC, is applied to study the vorticity field around a baffle and around the fluid-gas interface to highlight the dissipation mechanisms at different slosh amplitudes. Previous measurement data is then used to validate the CFD damping results. The study found several critical parameters controlling fluid damping from a baffle: local slosh amplitude to baffle thickness (A/t), surface liquid depth to tank radius (d/R), local slosh amplitude to baffle width (A/W); and non-dimensional slosh frequency. The simulation highlights three significant damping regimes where different mechanisms dominate. The study proves that the previously found discrepancies between Miles equation and experimental measurement are not due to the measurement scatter, but rather due to different damping mechanisms at various slosh amplitudes. The limitations on the use of Miles equation are discussed based on the flow regime.

Investigation of Damping Physics and CFD Tool Validation for Simulation of Baffled Tanks at Variable Slosh Amplitude

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeff

2016-01-01

Determination of slosh damping is a very challenging task as there is no analytical solution. The damping physics involves the vorticity dissipation which requires the full solution of the nonlinear Navier-Stokes equations. As a result, previous investigations were mainly carried out by extensive experiments. A systematical study is needed to understand the damping physics of baffled tanks, to identify the difference between the empirical Miles equation and experimental measurements, and to develop new semi-empirical relations to better represent the real damping physics. The approach of this study is to use Computational Fluid Dynamics (CFD) technology to shed light on the damping mechanisms of a baffled tank. First, a 1-D Navier-Stokes equation representing different length scales and time scales in the baffle damping physics is developed and analyzed. Loci-STREAM-VOF, a well validated CFD solver developed at NASA MSFC, is applied to study the vorticity field around a baffle and around the fluid-gas interface to highlight the dissipation mechanisms at different slosh amplitudes. Previous measurement data is then used to validate the CFD damping results. The study found several critical parameters controlling fluid damping from a baffle: local slosh amplitude to baffle thickness (A/t), surface liquid depth to tank radius (d/R), local slosh amplitude to baffle width (A/W); and non-dimensional slosh frequency. The simulation highlights three significant damping regimes where different mechanisms dominate. The study proves that the previously found discrepancies between Miles equation and experimental measurement are not due to the measurement scatter, but rather due to different damping mechanisms at various slosh amplitudes. The limitations on the use of Miles equation are discussed based on the flow regime.

Large panel design for containment air baffle

DOEpatents

Orr, Richard S.

1992-01-01

The movable air baffle shield means in accordance with the present invention provides an efficient method of cooling the space surrounding the containment vessel while also providing the capability of being moved away from the containment vessel during inspection. The containment apparatus comprises a generally cylindrical sealed containment vessel for containing at least a portion of a nuclear power generation plant, a disparate shield building surrounding and housing the containment vessel therein and spaced outwardly thereof so as to form an air annulus in the space between the shield building and the containment vessel, a shield baffle means positioned in the air annulus around at least a portion of the sides of the containment vessel providing a coolant path between the baffle means and the containment vessel to permit cooling of the containment vessel by air, the shield baffle means being movable to afford access to the containment vessel.

Large panel design for containment air baffle

DOEpatents

Orr, R.S.

1992-12-08

The movable air baffle shield means in accordance with the present invention provides an efficient method of cooling the space surrounding the containment vessel while also providing the capability of being moved away from the containment vessel during inspection. The containment apparatus comprises a generally cylindrical sealed containment vessel for containing at least a portion of a nuclear power generation plant, a disparate shield building surrounding and housing the containment vessel therein and spaced outwardly thereof so as to form an air annulus in the space between the shield building and the containment vessel, a shield baffle means positioned in the air annulus around at least a portion of the sides of the containment vessel providing a coolant path between the baffle means and the containment vessel to permit cooling of the containment vessel by air, the shield baffle means being movable to afford access to the containment vessel. 9 figs.

Validation of High-Resolution CFD Method for Slosh Damping Extraction of Baffled Tanks

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeff

2016-01-01

The predicted slosh damping values from Loci-Stream-VOF agree with experimental data very well for all fill levels in the vicinity of the baffle. Grid refinement study is conducted and shows that the current predictions are grid independent. The increase of slosh damping due to the baffle is shown to arise from: a) surface breakup; b) cascade of energy from the low order slosh mode to higher modes; and c) recirculation inside liquid phase around baffle. The damping is a function of slosh amplitude, consistent with previous observation. Miles equation under predicts damping in the upper dome section.

Liquid rocket engine combustion stabilization devices

NASA Technical Reports Server (NTRS)

1974-01-01

Combustion instability, which results from a coupling of the combustion process and the fluid dynamics of the engine system, was investigated. The design of devices which reduce coupling (combustion chamber baffles) and devices which increase damping (acoustic absorbers) are described. Included in the discussion are design criteria and recommended practices, structural and mechanical design, thermal control, baffle geometry, baffle/engine interactions, acoustic damping analysis, and absorber configurations.

Superwide-angle coverage code-multiplexed optical scanner.

PubMed

Riza, Nabeel A; Arain, Muzammil A

2004-05-01

A superwide-angle coverage code-multiplexed optical scanner is presented that has the potential to provide 4 pi-sr coverage. As a proof-of-concept experiment, an angular scan range of 288 degrees for six randomly distributed beams is demonstrated. The proposed scanner achieves its superwide coverage by exploiting a combination of phase-encoded transmission and reflection holography within an in-line hologram recording-retrieval geometry. The basic scanner unit consists of one phase-only digital mode spatial light modulator for code entry (i.e., beam scan control) and a holographic material from which we obtained what we believe is the first-of-a-kind extremely wide coverage, low component count, high speed (e.g., microsecond domain), and large aperture (e.g., > 1-cm diameter) scanner.

The efficiency of gravity distribution devices for on-site wastewater treatment systems.

PubMed

Patel, T; O'Luanaigh, N; Gill, L W

2008-01-01

A detailed analysis of different types of gravity distribution devices, designed to split on-site wastewater effluent equally between percolation trenches, has been carried out both in the laboratory and also in the field under realistic loading conditions. Five different types of distribution device have been compared: a V-notch distribution box, stilling chamber box, T-splitters with and without baffles and tipping bucket device. The trials carried out in the laboratory with clean water showed that flow distribution for all devices was sensitive to both the off-level installation angles and variable flow rates, with the most stable performance achieved using the T-splitters with baffles and tipping bucket devices. In parallel to this, the on-site flow regime experienced at two sites was continuously monitored using a tipping bucket and data-logger over eighteen month periods, finding that the most common flow rates at the distribution unit were in the range of 0.1-2.5 L/min. The on-site performance of these devices receiving both septic tank and secondary treated effluent showed that significant solid deposition and biofilm development had severely affected the equal distribution between the trenches, hence highlighting the need for regular maintenance to ensure efficient performance over time after installation. IWA Publishing 2008.

A Computational Fluid Dynamics Study of Swirling Flow Reduction by Using Anti-Vortex Baffle

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeff; Peugeot, John W.

2017-01-01

OBJECTIVES: To evaluate proposed anti-vortex design in suppressing swirling flow during US burn. APPROACH: Include two major body forces in the analysis a)Vehicle acceleration (all three components); b)Vehicle maneuvers (roll, pitch, and yaw). Perform two drainage analyses of Ares I LOX tank using 6 DOF body forces predicted by GN&C analysis (Guidance Navigation and Control) during vehicle ascent: one with baffle, one without baffle. MODEL: Use Ares I defined geometry. O-Grid for easy fitting of baffle. In this preliminary analysis the holes are sealed. Use whole 360 deg. model with no assumption of symmetry or cyclic boundary conditions. Read in 6DOF data vs time from a file.

Dilution jet mixing program, phase 3

NASA Technical Reports Server (NTRS)

Srinivasan, R.; Coleman, E.; Myers, G.; White, C.

1985-01-01

The main objectives for the NASA Jet Mixing Phase 3 program were: extension of the data base on the mixing of single sided rows of jets in a confined cross flow to discrete slots, including streamlined, bluff, and angled injections; quantification of the effects of geometrical and flow parameters on penetration and mixing of multiple rows of jets into a confined flow; investigation of in-line, staggered, and dissimilar hole configurations; and development of empirical correlations for predicting temperature distributions for discrete slots and multiple rows of dilution holes.

Annular flow diverter valve

DOEpatents

Rider, Robert L.

1980-01-01

A valve for diverting flow from the center of two concentric tubes to the annulus between the tubes or, operating in the reverse direction, for mixing fluids from concentric tubes into a common tube and for controlling the volume ratio of said flow consists of a toroidal baffle disposed in sliding engagement with the interior of the inner tube downstream of a plurality of ports in the inner tube, a plurality of gates in sliding engagement with the interior of the inner tube attached to the baffle for movement therewith, a servomotor having a bullet-shaped plug on the downstream end thereof, and drive rods connecting the servomotor to the toroidal baffle, the servomotor thereby being adapted to move the baffle into mating engagement with the bullet-shaped plug and simultaneously move the gates away from the ports in the inner tube and to move the baffle away from the bullet-shaped plug and simultaneously move the gates to cover the ports in the inner tube.

High performance internal reforming unit for high temperature fuel cells

DOEpatents

Ma, Zhiwen [Sandy Hook, CT; Venkataraman, Ramakrishnan [New Milford, CT; Novacco, Lawrence J [Brookfield, CT

2008-10-07

A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

Gas filled panel insulation

DOEpatents

Griffith, Brent T.; Arasteh, Dariush K.; Selkowitz, Stephen E.

1993-01-01

A structural or flexible highly insulative panel which may be translucent, is formed from multi-layer polymeric material in the form of an envelope surrounding a baffle. The baffle is designed so as to minimize heat transfer across the panel, by using material which forms substantially closed spaces to suppress convection of the low conductivity gas fill. At least a portion of the baffle carries a low emissivity surface for suppression of infrared radiation.

Advanced Baffle Materials Technology Development

DTIC Science & Technology

1991-10-01

few baffle materials, data from Misty North and Diesel Train provide guidance on damage mechanisms and give points with which theory can be compared...adequate to permit correlation of theory with experiment for thin film baffle structures which can be approximated as a series of planes. No means of...etching to produce surface microtexture on samples of 3 aluminum (see Figure 3-5). Current theory predicts that sputter texture etching works because

Influence of slosh baffles on thermodynamic performance in liquid hydrogen tank.

PubMed

Liu, Zhan; Li, Cui

2018-03-15

A calibrated CFD model is built to investigate the influence of slosh baffles on the pressurization performance in liquid hydrogen (LH 2 ) tank. The calibrated CFD model is proven to have great predictive ability by compared against the flight experimental results. The pressure increase, thermal stratification and wall heat transfer coefficient of LH 2 tank have been detailedly studied. The results indicate that slosh baffles have a great influence on tank pressure increase, fluid temperature distribution and wall heat transfer. Owning to the existence of baffles, the stratification thickness increases gradually with the distance from tank axis to tank wall. While for the tank without baffles, the stratification thickness decreases firstly and then increases with the increase of the distance from the axis. The "M" type stratified thickness distribution presents in tank without baffles. One modified heat transfer coefficient correlation has been proposed with the change of fluid temperature considered by multiplying a temperature correction factor. It has been proven that the average relative prediction errors of heat transfer coefficient reduced from 19.08% to 4.98% for the wet tank wall of the tank, from 8.93% to 4.27% for the dry tank wall, respectively, calculated by the modified correlation. Copyright © 2017 Elsevier B.V. All rights reserved.

Research on effects of baffle position in an integrating sphere on the luminous flux measurement

NASA Astrophysics Data System (ADS)

Lin, Fangsheng; Li, Tiecheng; Yin, Dejin; Lai, Lei; Xia, Ming

2016-09-01

In the field of optical metrology, luminous flux is an important index to characterize the quality of electric light source. Currently, the majority of luminous flux measurement is based on the integrating sphere method, so measurement accuracy of integrating sphere is the key factor. There are plenty of factors affecting the measurement accuracy, such as coating, power and the position of light source. However, the baffle which is a key part of integrating sphere has important effects on the measurement results. The paper analyzes in detail the principle of an ideal integrating sphere. We use moving rail to change the relative position of baffle and light source inside the sphere. By experiments, measured luminous flux values at different distances between the light source and baffle are obtained, which we used to take analysis of the effects of different baffle position on the measurement. By theoretical calculation, computer simulation and experiment, we obtain the optimum position of baffle for luminous flux measurements. Based on the whole luminous flux measurement error analysis, we develop the methods and apparatus to improve the luminous flux measurement accuracy and reliability. It makes our unifying and transferring work of the luminous flux more accurate in East China and provides effective protection for our traceability system.

Effect of Baffle on Gravity-Gradient-Excited Slosh Waves and Spacecraft Moment and Angular-Momentum Fluctuations in Microgravity

NASA Technical Reports Server (NTRS)

Hung, R. J.; Lee, C. C.

1995-01-01

The dynamical behavior of fluids affected by the asymmetric gravity gradient acceleration has been investigated. In particular, the effects of surface tension on partially filled rotating fluids applicable to a full-scale Gravity Probe-B Spacecraft dewar tank with and without baffles are studied. Results of slosh wave excitation along the liquid-vapor interface induced by gravity gradient acceleration indicate that the gravity gradient acceleration is equivalent to the combined effect of a twisting force and a torsional moment acting on the spacecraft. The results are clearly seen from one-up one-down and one-down one-up oscillations in the cross-section profiles of two bubbles in the vertical (r, z)-plane of the rotating dewar, and from the eccentric contour of the bubble rotating around the axis of the dewar in a horizontal (r, theta)-plane. As the viscous force, between liquid and solid interface, greatly contributes to the damping of slosh wave excitation, a rotating dewar with baffles provides more areas of liquid-solid interface than that of a rotating dewar without baffles. Results show that the damping effect provided by the baffles reduces the amplitude of slosh wave excitation and lowers the degree of asymmetry in liquid-vapor distribution. Fluctuations of angular momentum and fluid moment caused by the slosh wave excited by gravity gradient acceleration with and without baffle boards are also investigated. It is also shown that the damping effect provided by the baffles greatly reduces the amplitudes of angular momentum and fluid moment fluctuations.

Design and evaluation of hydraulic baffled-channel PAC contactor for taste and odor removal from drinking water supplies.

PubMed

Kim, Young-Il; Bae, Byung-Uk

2007-05-01

Based on the concept of hydraulic flocculator, a baffled-channel powdered activated carbon (PAC) contactor, placed before the rapid-mixing basin, was designed and evaluated for removal of taste and odor (T&O) in drinking water. PAC adsorption kinetic tests for raw water samples were conducted for selection of design parameters related to contact time and degree of mixing. Within the tested range of velocity gradient (G) from 18 to 83s(-1), mixing had a relatively minor effect on the adsorption kinetics of the PAC. The hydrodynamic characteristics of the pilot-scale horizontally and vertically baffled-channel PAC contactor were investigated by tracer tests. It was found that the plug flow fractions of vertically baffled-channel PAC contactor (vBPC) were higher than those of the horizontally baffled-channel PAC contactor (hBPC) for the same bend width or bend height. However, the hBPC seems to be more appropriate than the vBPC in terms of construction and maintenance. The geosmin and MIB removal rate increased with the number of baffles, PAC dose and contact time increased regardless of bend width in the pilot-scale hBPC. The pair of full-scale hBPCs at Pohang water treatment plant, having a design capacity of 6.5x10(4)m(3)/d with 20min of hydraulic retention time with a safety factor of 2, was designed based on lab- and pilot-scale experimental results. Under a velocity gradient of 20s(-1), the number of baffles to be installed was calculated to be 20 with a space of about 2m between each baffle, resulting in a hydraulic head loss through the contactor of about 0.056m. The successful application of hBPC for T&O removal from drinking water supplies should provide momentum for developing more effective treatment methods.

Verifying mixing in dilution tunnels How to ensure cookstove emissions samples are unbiased

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, Daniel L.; Rapp, Vi H.; Caubel, Julien J.

A well-mixed diluted sample is essential for unbiased measurement of cookstove emissions. Most cookstove testing labs employ a dilution tunnel, also referred to as a “duct,” to mix clean dilution air with cookstove emissions before sampling. It is important that the emissions be well-mixed and unbiased at the sampling port so that instruments can take representative samples of the emission plume. Some groups have employed mixing baffles to ensure the gaseous and aerosol emissions from cookstoves are well-mixed before reaching the sampling location [2, 4]. The goal of these baffles is to to dilute and mix the emissions stream withmore » the room air entering the fume hood by creating a local zone of high turbulence. However, potential drawbacks of mixing baffles include increased flow resistance (larger blowers needed for the same exhaust flow), nuisance cleaning of baffles as soot collects, and, importantly, the potential for loss of PM2.5 particles on the baffles themselves, thus biasing results. A cookstove emission monitoring system with baffles will collect particles faster than the duct’s walls alone. This is mostly driven by the available surface area for deposition by processes of Brownian diffusion (through the boundary layer) and turbophoresis (i.e. impaction). The greater the surface area available for diffusive and advection-driven deposition to occur, the greater the particle loss will be at the sampling port. As a layer of larger particle “fuzz” builds on the mixing baffles, even greater PM2.5 loss could occur. The micro structure of the deposited aerosol will lead to increased rates of particle loss by interception and a tendency for smaller particles to deposit due to impaction on small features of the micro structure. If the flow stream could be well-mixed without the need for baffles, these drawbacks could be avoided and the cookstove emissions sampling system would be more robust.« less

Gas filled panel insulation

DOEpatents

Griffith, B.T.; Arasteh, D.K.; Selkowitz, S.E.

1993-12-14

A structural or flexible highly insulative panel which may be translucent, is formed from multi-layer polymeric material in the form of an envelope surrounding a baffle. The baffle is designed so as to minimize heat transfer across the panel, by using material which forms substantially closed spaces to suppress convection of the low conductivity gas fill. At least a portion of the baffle carries a low emissivity surface for suppression of infrared radiation. 18 figures.

Validation of High-Resolution CFD Method for Slosh Damping Extraction of Baffled Tanks

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeff

2016-01-01

Determination of slosh damping is a very challenging task as there is no analytical solution. The damping physics involve the vorticity dissipation which requires the full solution of the nonlinear Navier-Stokes equations. As a result, previous investigations and knowledge were mainly carried out by extensive experimental studies. A Volume-Of-Fluid (VOF) based CFD program developed at NASA MSFC was applied to extract slosh damping in a baffled tank from the first principle. First, experimental data using water with subscale smooth wall tank were used as the baseline validation. CFD simulation was demonstrated to be capable of accurately predicting natural frequency and very low damping value from the smooth wall tank at different fill levels. The damping due to a ring baffle at different liquid fill levels from barrel section and into the upper dome was then investigated to understand the slosh damping physics due to the presence of a ring baffle. Based on this study, the Root-Mean-Square error of our CFD simulation in estimating slosh damping was less than 4.8%, and the maximum error was less than 8.5%. Scalability of subscale baffled tank test using water was investigated using the validated CFD tool, and it was found that unlike the smooth wall case, slosh damping with baffle is almost independent of the working fluid and it is reasonable to apply water test data to the full scale LOX tank when the damping from baffle is dominant. On the other hand, for the smooth wall, the damping value must be scaled according to the Reynolds number. Comparison of experimental data, CFD, with the classical and modified Miles equations for upper dome was made, and the limitations of these semi-empirical equations were identified.

Effect of transcatheter closure of baffle leaks following senning or mustard atrial redirection surgery on oxygen saturations and polycythaemia.

PubMed

Bentham, James; English, Kate; Hares, Dominic; Gibbs, John; Thomson, John

2012-10-01

The aim of this study was to describe the clinical importance and methods of transcatheter closure of systemic venous baffle leaks after atrial redirection procedures for transposed great vessels. Until the late 1970s, atrial redirection surgery was the principal surgical palliative approach to manage transposed great vessels. Baffle leaks are among the many long-term complications of this type of surgery, and their prevalence increases over time. The clinical consequences of baffle leaks in this population are poorly understood, and the indications for closure are incompletely defined. During outpatient follow-up of 126 patients after atrial redirection surgery, 15 baffle leaks were detected in 11 patients. All underwent transcatheter closure using either an occluding device or a covered stent if there was concomitant baffle obstruction. The average age at the time of the procedure was 26 years (range 6 to 42). Ten of 11 patients were cyanosed at rest or on a simple walk test (median oxygen saturation level 80%, range 65% to 96%). Six of 11 patients were polycythemic before leak closure (median hemoglobin concentration 19 g/dl, range 13.8 to 23). After closure, there was a significant improvement in saturation (median 97%, p <0.0001) and a significant reduction in hemoglobin concentration at 6 months after the procedure (median 14.8 g/dl, p <0.05). There were no procedural adverse events. One patient experienced late device embolization necessitating surgical removal. In conclusion, transcatheter closure of baffle leaks is a technically feasible although frequently complex and lengthy procedure. Closure is associated with an improvement in oxygen saturations and a reduction in polycythaemia. Copyright © 2012 Elsevier Inc. All rights reserved.

Self-defrosting recuperative air-to-air heat exchanger

DOEpatents

Drake, Richard L.

1993-01-01

A heat exchanger includes a stationary spirally or concentrically wound heat exchanger core with rotating baffles on upper and lower ends thereof. The rotating baffles include rotating inlets and outlets which are in communication with respective fixed inlets and outlets via annuli. The rotation of the baffles causes a concurrent rotation of the temperature distribution within the stationary exchanger core, thereby preventing frost build-up in some applications and preventing the formation of hot spots in other applications.

REDISTRIBUTOR FOR LIQUID-LIQUID EXTRACTION COLUMNS

DOEpatents

Bradley, J.G.

1957-10-29

An improved baffle plate construction to intimately mix immiscible liquid solvents for solvent extraction processes in a liquid-liquid pulse column is described. To prevent the light and heavy liquids from forming separate continuous homogeneous vertical channels through sections of the column, a baffle having radially placed rectangular louvers with deflection plates opening upon alternate sides of the baffle is placed in the column, normal to the axis. This improvement substantially completely reduces strippiig losses due to poor mixing.

Stray light suppression of optical and mechanical system for telescope detection

NASA Astrophysics Data System (ADS)

Wang, Lei; Ma, Wenli

2013-09-01

During telescope detection, there is atmosphere overflow and other stray light affecting the system which leads to background disturbance. Thus reduce the detection capability of the system. So it is very necessary to design mechanical structure to suppress the stray light for the telescope detection system. It can both improve the signal-to-noise and contrast of the object. This paper designs the optical and mechanical structure of the 400mm telescope. And then the main baffle, baffle vane, field stop and coating technology are used to eliminate the effect of stray light on the optical and mechanical system. Finally, software is used to analyze and simulate stray light on the whole optical and mechanical system. Using PST as the evaluating standard, separate and integrated analysis of the suppressing effect of main baffle, baffle vane and field aperture is completed. And also get the results of PST before and after eliminating the stray light. Meanwhile, the results of stray light analysis can be used to guide the design of the optical and mechanical structure. The analysis results demonstrate that reasonable optical and mechanical structure and stray light suppression measure can highly reduce the PST and also improve the detection capability of the telescope system, and the designed outside baffle, inside baffle, vanes and coating technique etc. can decrease the PST approximately 1 to 3 level.

Numerical Analysis of Edge Over Coating and Baffle Effect on Hot-Dip Galvanizing

NASA Astrophysics Data System (ADS)

Bao, Chengren; Kang, Yonglin; Li, Yan

2017-06-01

In hot-dip galvanizing process, air jet wiping control is so crucial to determine the coating thickness and uniformity of the zinc layer on the steel strip. A numerical simulation of gas-jet wiping in hot-dip galvanizing was conducted to minimize the occurrence of edge over coating (EOC). The causes of EOC were identified by contrasting and analyzing the airflow fields on the strip edge with and without a baffle. The factors influencing the airflow field on the strip edge during the change in the gap between the baffle and the strip edge were also analyzed. The effect of the distance between the air knife and the strip was evaluated. Technological parameters with on-site guidance role were obtained by combining them with the actual production to elucidate the role of the baffle in restraining the occurrence of EOC. The uniform distribution of pressure and coating thickness on the strip is achieved when the distance of the baffle from the strip edge is about 0.3 times of the jetting distance.

Removal of nutrients from septic tank effluent with baffle subsurface-flow constructed wetlands.

PubMed

Cui, Lihua; Ouyang, Ying; Yang, Weizhi; Huang, Zhujian; Xu, Qiaoling; Yu, Guangwei

2015-04-15

Three new baffle flow constructed wetlands (CWs), namely the baffle horizontal flow CW (Z1), baffle vertical flow CW (Z2) and baffle hybrid flow CW (Z3), along with one traditional horizontal subsurface flow CW (Z4) were designed to test the removal efficiency of nitrogen (N) and phosphorus (P) from the septic tank effluent under varying hydraulic retention times (HRTs). Results showed that the optimal HRT was two days for maximal removal of N and P from the septic tank effluent among the four CWs. At this HRT, the Z1, Z2, Z3 and Z4 CWs removed, respectively, 49.93, 58.50, 46.01 and 44.44% of TN as well as 87.82, 93.23, 95.97 and 91.30% of TP. Our study further revealed that the Z3 CW was the best design for overall removal of N and P from the septic tank effluent due to its hybrid flow directions with better oxygen supply inside the CW system. Copyright © 2015 Elsevier Ltd. All rights reserved.

Optical system for determining physical characteristics of a solar cell

DOEpatents

Sopori, Bhushan L.

2001-01-01

The invention provides an improved optical system for determining the physical characteristics of a solar cell. The system comprises a lamp means for projecting light in a wide solid-angle onto the surface of the cell; a chamber for receiving the light through an entrance port, the chamber having an interior light absorbing spherical surface, an exit port for receiving a beam of light reflected substantially normal to the cell, a cell support, and an lower aperture for releasing light into a light absorbing baffle; a means for dispersing the reflection into monochromatic components; a means for detecting an intensity of the components; and a means for reporting the determination.

Experimental investigation of piercing of high-strength steels within a critical range of slant angle

NASA Astrophysics Data System (ADS)

Senn, S.; Liewald, M.

2017-09-01

Deep drawn parts often do have complex designs and, therefore, must be trimmed or punched subsequently in a second stage. Due to the complex part geometry, most punching areas do reveal critical slant angle (angle between part surface and ram movement direction) different to perpendicular direction. Piercing within a critical range of slant angle may lead to severe damage of the cutting tool. Consequently, expensive cam units are required to transform the ram moving direction in order to perform the piercing process perpendicularly to the local part surface. For modern sheet metals, however, the described critical angle of attack has not been investigated adequately until now. Therefore, cam units are used in cases in which regular piercing with high slant angle wouldn’t be possible. Purpose of this study is to investigate influencing factors and their effect on punch damage during piercing of high strength steels with slant angles. Therefore, a modular shearing tool was designed, which allows to simply switch die parts to vary cutting clearance and cutting angle. The target size of the study is to measure the lateral deviation of the punch which is monitored by an eddy current sensor. The sensor is located in the downholder and measures the lateral punch deviation in-line during manufacturing. The deviation is mainly influenced by slant angle of workpiece surface. In relation to slang angle and sheet thickness the clearance has a small influence on the measured punch deflection.

Self-defrosting recuperative air-to-air heat exchanger

DOEpatents

Drake, R.L.

1993-12-28

A heat exchanger is described which includes a stationary spirally or concentrically wound heat exchanger core with rotating baffles on upper and lower ends thereof. The rotating baffles include rotating inlets and outlets which are in communication with respective fixed inlets and outlets via annuli. The rotation of the baffles causes a concurrent rotation of the temperature distribution within the stationary exchanger core, thereby preventing frost build-up in some applications and preventing the formation of hot spots in other applications. 3 figures.

Liquid metal reactor air cooling baffle

DOEpatents

Hunsbedt, Anstein

1994-01-01

A baffle is provided between a relatively hot containment vessel and a relatively cold silo for enhancing air cooling performance. The baffle includes a perforate inner wall positionable outside the containment vessel to define an inner flow riser therebetween, and an imperforate outer wall positionable outside the inner wall to define an outer flow riser therebetween. Apertures in the inner wall allow thermal radiation to pass laterally therethrough to the outer wall, with cooling air flowing upwardly through the inner and outer risers for removing heat.

Liquid metal reactor air cooling baffle

DOEpatents

Hunsbedt, A.

1994-08-16

A baffle is provided between a relatively hot containment vessel and a relatively cold silo for enhancing air cooling performance. The baffle includes a perforate inner wall positionable outside the containment vessel to define an inner flow riser therebetween, and an imperforate outer wall positionable outside the inner wall to define an outer flow riser therebetween. Apertures in the inner wall allow thermal radiation to pass laterally therethrough to the outer wall, with cooling air flowing upwardly through the inner and outer risers for removing heat. 3 figs.

Wide-angle flat field telescope

NASA Technical Reports Server (NTRS)

Hallam, K. L.; Howell, B. J.; Wilson, M. E.

1986-01-01

Described is an unobscured three mirror wide angle telescopic imaging system comprised of an input baffle which provides a 20 deg (Y axis) x 30 deg (X axis) field of view, a primary mirror having a convex spherical surface, a secondary mirror having a concave ellipsoidal reflecting surface, a tertiary mirror having a concave spherical reflecting surface. The mirrors comprise mirror elements which are offset segments of parent mirrors whose axes and vertices commonly lie on the system's optical axis. An iris diaphragm forming an aperture stop is located between the secondary and tertiary mirror with its center also being coincident with the optical axis and being further located at the beam waist of input light beams reflected from the primary and secondary mirror surfaces. At the system focus following the tertiary mirror is located a flat detector which may be, for example, a TV imaging tube or a photographic film. When desirable, a spectral transmission filter is placed in front of the detector in close proximity thereto.

Bidirectional reflectance distribution function /BRDF/ measurements of stray light suppression coatings for the Space Telescope /ST/

NASA Technical Reports Server (NTRS)

Griner, D. B.

1979-01-01

The paper considers the bidirectional reflectance distribution function (BRDF) of black coatings used on stray light suppression systems for the Space Telescope (ST). The ST stray light suppression requirement is to reduce earth, moon, and sun light in the focal plane to a level equivalent to one 23 Mv star per square arcsecond, an attenuation of 14 orders of magnitude. It is impractical to verify the performance of a proposed baffle system design by full scale tests because of the large size of the ST, so that a computer analysis is used to select the design. Accurate computer analysis requires a knowledge of the diffuse scatter at all angles from the surface of the coatings, for all angles of incident light. During the early phases of the ST program a BRDF scanner was built at the Marshall Space Flight Center to study the scatter from black materials; the measurement system is described and the results of measurements on samples proposed for use on the ST are presented.

Passage and behaviour of cultured Lake Sturgeon in a prototype side-baffle fish ladder: I. Ladder hydraulics and fish ascent

USGS Publications Warehouse

Kynard, B.; Pugh, D.; Parker, T.

2011-01-01

Research and development of a fish ladder for sturgeons requires understanding ladder hydraulics and sturgeon behaviour in the ladder to insure the ladder is safe and provides effective passage. After years of research and development, we designed and constructed a full-scale prototype side-baffle ladder inside a spiral flume (38.3m long??1m wide??1m high) on a 6% (1:16.5) slope with a 1.92-m rise in elevation (bottom to top) to test use by sturgeons. Twenty-eight triangular side baffles, each extending part way across the flume, alternated from inside wall to outside wall down the ladder creating two major flow habitats: a continuous, sinusoidal flow down the ladder through the vertical openings of side-baffles and an eddy below each side baffle. Ascent and behaviour was observed on 22 cultured Lake Sturgeon=LS (Acipenser fulvescens) repeatedly tested in groups as juveniles (as small as 105.1cm TL, mean) or as adults (mean TL, 118cm) during four periods (fall 2002 and 2003; spring 2003 and 2007). Percent of juveniles entering the ladder that ascended to the top was greater in spring (72.7%) than in fall (40.9-45.5%) and 90.9% of 11 adults, which ascended as juveniles, ascended to the top. Six LS (27.3%) never swam to the top and seven (31.8%) swam to the top in all tests, indicating great variability among individuals for ascent drive. Some LS swam directly to the top in <1min, but most rested in an eddy during ascent. Juveniles swimming through outside wall baffle slots (mean velocity, 1.2ms-1) swam at 1.8-2.2body lengthss-1 and 3.2-3.3tail beatss-1, either at or approaching prolonged swimming speed. The side-baffle ladder was stream-like and provided key factors for a sturgeon ladder: a continuous flow and no full cross-channel walls, abundant eddies for resting, an acceptable water depth, and a water velocity fish could ascend swimming 2bls-1. A side-baffle ladder passes LS and other moderate-swimming fishes. ?? 2011 Blackwell Verlag, Berlin.

Lens-and-Detector Array for Spectrometer

NASA Technical Reports Server (NTRS)

Oberheuser, J.

1985-01-01

Supporting structure alines lenses and serves as light baffle. Lenses and infrared detectors mounted together in cavities in electroformed plate. Plate and cavities maintain optical alinement while serving as light baffle and aperture stop.

A theoretical evaluation of rigid baffles in suppression of combustion instability

NASA Technical Reports Server (NTRS)

Baer, M. R.; Mitchell, C. E.

1976-01-01

An analytical technique for the prediction of the effects of rigid baffles on the stability of liquid propellant combustors is presented. A three dimensional combustor model characterized by a concentrated combustion source at the chamber injector and a constant Mach number nozzle is used. The linearized partial differential equations describing the unsteady flow field are solved by an eigenfunction matching method. Boundary layer corrections to this unsteady flow are used to evaluate viscous and turbulence effects within the flow. An integral stability relationship is then employed to predict the decay rate of the oscillations. Results show that sufficient dissipation exists to indicate that the proper mechanism of baffle damping is a fluid dynamic loss. The response of the dissipation model to varying baffle blade length, mean flow Mach number and oscillation amplitude is examined.

Apparatus for separating and recovering hydrogen isotopes

DOEpatents

Heung, Leung K.

1994-01-01

An apparatus for recovering hydrogen and separating its isotopes. The apparatus includes a housing bearing at least a fluid inlet and a fluid outlet. A baffle is disposed within the housing, attached thereto by a bracket. A hollow conduit is coiled about the baffle, in spaced relation to the baffle and the housing. The coiled conduit is at least partially filled with a hydride. The hydride can be heated to a high temperature and cooled to a low temperature quickly by circulating a heat transfer fluid in the housing. The spacing between the baffle and the housing maximizes the heat exchange rate between the fluid in the housing and the hydride in the conduit. The apparatus can be used to recover hydrogen isotopes (protium, deuterium and tritium) from gaseous mixtures, or to separate hydrogen isotopes from each other.

Suppression of sun interference in the star sensor baffling stray light by total internal reflection

NASA Astrophysics Data System (ADS)

Kawano, Hiroyuki; Shimoji, Haruhiko; Yoshikawa, Shoji; Miyatake, Katsumasa; Hama, Kazumori; Nakamura, Shuji

2005-09-01

We have developed a star sensor as an experimental device onboard the SERVIS-1 satellite launched in October 2003. The in-orbit data have verified its fundamental performance. One of the advantages of our star sensor is that the baffle has a small length of 120 mm instead of 182 mm in the conventional two-stage baffle design. The key concepts for light shielding are total internal reflection phenomena inside a nearly half sphere (NHS) lens and scattering light control by gloss black paint. However, undesirable background noise by the sun outside of the field of view (FOV) was observed in the corner of the FOV in the orbital experiment. Ray trace simulations revealed that slight scattering light on the specular baffle wall entered the NHS lens and reached the corner of the image sensor through the multi-reflection path inside the lens. It was found that the stray light path can be shielded effectively if the diameter of the aperture under the NHS lens was reduced. We redesigned the baffle and evaluated the light shielding ability with our sun interference test facility on the ground, and confirmed that the stray light was reduced below the acceptable level. As a result, the light shielding technique which we have proposed was proved to be effective for a small-size baffle. The redesigned star sensor is planned to be installed as a main attitude sensor for the SERVIS-2 satellite scheduled to be launched in February 2008.

Context-sensitive trace inlining for Java.

PubMed

Häubl, Christian; Wimmer, Christian; Mössenböck, Hanspeter

2013-12-01

Method inlining is one of the most important optimizations in method-based just-in-time (JIT) compilers. It widens the compilation scope and therefore allows optimizing multiple methods as a whole, which increases the performance. However, if method inlining is used too frequently, the compilation time increases and too much machine code is generated. This has negative effects on the performance. Trace-based JIT compilers only compile frequently executed paths, so-called traces, instead of whole methods. This may result in faster compilation, less generated machine code, and better optimized machine code. In the previous work, we implemented a trace recording infrastructure and a trace-based compiler for [Formula: see text], by modifying the Java HotSpot VM. Based on this work, we evaluate the effect of trace inlining on the performance and the amount of generated machine code. Trace inlining has several major advantages when compared to method inlining. First, trace inlining is more selective than method inlining, because only frequently executed paths are inlined. Second, the recorded traces may capture information about virtual calls, which simplify inlining. A third advantage is that trace information is context sensitive so that different method parts can be inlined depending on the specific call site. These advantages allow more aggressive inlining while the amount of generated machine code is still reasonable. We evaluate several inlining heuristics on the benchmark suites DaCapo 9.12 Bach, SPECjbb2005, and SPECjvm2008 and show that our trace-based compiler achieves an up to 51% higher peak performance than the method-based Java HotSpot client compiler. Furthermore, we show that the large compilation scope of our trace-based compiler has a positive effect on other compiler optimizations such as constant folding or null check elimination.

Moisture-resistant baffle material for fuel tanks

NASA Technical Reports Server (NTRS)

Bilow, N.

1974-01-01

Test results indicated superiority of certain polyether-based polyurethanes as protective coatings and suggested that baffle-materials with one of these coatings should have useful life approximately twice that of uncoated foams now in use.

Preservation of Thermal Control Specular Gold Baffle Surface on the James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM) Electronics Compartment (IEC)

NASA Technical Reports Server (NTRS)

MonteedeGarcia, Kristina; Patel, Jignasha; Perry, Radford, III

2010-01-01

Extremely tight thermal control property degradation allowances on the vapor-deposited, gold-coated IEC baffle surface, made necessary by the cryogenic JWST Observatory operations, dictate tight contamination requirements on adjacent surfaces. Theoretical degradation in emittance with contaminant thickness was calculated. Maximum allowable source outgassing rates were calculated using worst case view factors from source to baffle surface. Tight requirements pushed the team to change the design of the adjacent surfaces to minimize the outgassing sources

Preservation of thermal control specular gold baffle surface on the James Webb Space Telescope (JWST) integrated science instrument module (ISIM) electronics compartment (IEC)

NASA Astrophysics Data System (ADS)

Montt de Garcia, Kristina; Patel, Jignasha; Perry, Radford, III

2010-08-01

Extremely tight thermal control property degradation allowances on the vapor-deposited, gold-coated IEC baffle surface, made necessary by the cryogenic JWST Observatory operations, dictate tight contamination requirements on adjacent surfaces. Theoretical degradation in emittance with contaminant thickness was calculated. Maximum allowable source outgassing rates were calculated using worst case view factors from source to baffle surface. Tight requirements pushed the team to change the design of the adjacent surfaces to minimize the outgassing sources.

Enhanced solution velocity between dark and light areas with horizontal tubes and triangular prism baffles to improve microalgal growth in a flat-panel photo-bioreactor.

PubMed

Yang, Zongbo; Cheng, Jun; Xu, Xiaodan; Zhou, Junhu; Cen, Kefa

2016-07-01

Novel horizontal tubes and triangular prism (HTTP) baffles that generate flow vortices were developed to increase solution velocity between dark and light areas and thus improve microalgal growth in a flat-panel photo-bioreactor. Solution velocity, mass-transfer coefficient, and mixing time were measured with a particle-imaging velocimeter, dissolved oxygen probes, and pH probes. The solution mass-transfer coefficient increased by 30% and mixing time decreased by 21% when the HTTP baffles were used. The solution velocity between dark and light areas increased from ∼0.9cm/s to ∼3.5cm/s, resulting in a decreased dark-light cycle period to one-fourth. This enhanced flashing light effect with the HTTP baffles dramatically increased microalgae biomass yield by 70% in the flat-panel photo-bioreactor. Copyright © 2016 Elsevier Ltd. All rights reserved.

Internal baffling for fuel injector

DOEpatents

Johnson, Thomas Edward; Lacy, Benjamin; Stevenson, Christian

2014-08-05

A fuel injector includes a fuel delivery tube; a plurality of pre-mixing tubes, each pre-mixing tube comprising at least one fuel injection hole; an upstream tube support plate that supports upstream ends of the plurality of pre-mixing tubes; a downstream tube support plate that supports downstream ends of the plurality of pre-mixing tubes; an outer wall connecting the upstream tube support plate and the downstream tube support plate and defining a plenum therewith; and a baffle provided in the plenum. The baffle includes a radial portion. A fuel delivered in the upstream direction by the fuel delivery tube is directed radially outwardly in the plenum between the radial portion of the baffle and the downstream tube support plate, then in the downstream direction around an outer edge portion of the radial portion, and then radially inwardly between the radial portion and the upstream tube support plate.

Design of a projection display screen with vanishing color shift for rear-projection HDTV

NASA Astrophysics Data System (ADS)

Liu, Xiu; Zhu, Jin-lin

1996-09-01

Using bi-convex cylinder lens with matrix structure, the transmissive projection display screen with high contrast and wider viewing angle has been widely used in large rear projection TV and video projectors, it obtained a inhere color shift and puzzled the designer of display screen for RGB projection tube in-line adjustment. Based on the method of light beam racing, the general software of designing projection display screen has been developed and the computer model of vanishing color shift for rear projection HDTV has bee completed. This paper discussed the practical designing method to vanish the defect of color shift and mentioned the relations between the primary optical parameters of display screen and relative geometry sizes of lens' surface. The distributions of optical gain to viewing angle and the influences on engineering design are briefly analyzed.

High-resolution recording of particle tracks with in-line holography in a large cryogenic bubble chamber

NASA Astrophysics Data System (ADS)

Harigel, Gert G.

2000-10-01

Holography has been used successfully in combination with conventional optics for the first time in a large cryogenic bubble chamber, the 15-Foot Bubble Chamber at the Fermi National Accelerator Laboratory (FNAL), during a physics run in a high energy neutrino beam. The innovative system combined the reference beam with the object beam, irradiating a conical volume of approx1.5m3. Bubble tracks from neutrino interactions with a width of approx 120 micrometers have been recorded with good contrast. The ratio of intensities of the object light to the reference light striking the film is called the beam branching ratio (BBR). We obtained in our experiment an exceedingly small minimum- observable ration of BBR = (0.54 divided by 0.21) x 107. The technology has the potential for a wide range of applications. This paper describes the various difficulties in achieving the success. It required the development of laser pulse stretching via enhanced closed loop control with slow Q- switching, to overcome excessive heating of the cryogenic liquid by the powerful laser beam. A sophisticated system of light-absorbing baffles had to be installed to avoid stray light reaching the holographic film. Optical decoupling of classical and holographic illumination systems was required. Real and virtual image replay machines for holograms were built, tailored to our illumination technique.

Longitudinal discharge laser baffles

DOEpatents

Warner, Bruce E.; Ault, Earl R.

1994-01-01

The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam.

Slanted baffle mist eliminator

DOEpatents

Vance, Richard F.

1995-11-07

An apparatus for the elimination of mist from off-gas during vitrification f nuclear waste, where baffles are installed on a slant toward the flow of the off-gasses eliminating the need to expand the cross-sectional area of the duct size.

Sputtering phenomena of discharge chamber components in a 30-cm diameter Hg ion thruster

NASA Technical Reports Server (NTRS)

Mantenieks, M. A.; Rawlin, V. K.

1976-01-01

Sputtering and deposition rates were measured for discharge chamber components of a 30-cm diameter mercury ion thruster. It was found that sputtering rates of the screen grid and cathode baffle were strongly affected by geometry of the baffle holder. Sputtering rates of the baffle and screen grid were reduced to 80 and 125 A/hr, respectively, by combination of appropriate geometry and materials selections. Sputtering rates such as these are commensurate with thruster lifetimes of 15,000 hours or more. A semiempirical sputtering model showed good agreement with the measured values.

Intraatrial baffle repair of anomalous systemic venous return without hepatic venous drainage in heterotaxy syndrome.

PubMed

Turkoz, Riza; Ayabakan, Canan; Vuran, Can; Omay, Oğuz

2010-08-01

A 7-month-old boy with heterotaxy syndrome had partial atrioventricular septal defect and interrupted inferior vena cava with hemiazygos continuation to a left superior vena cava. The left side of the common atrium receiving all the venous drainage was in connection with the left ventricle and the aorta. The small atrium and the proximity of the pulmonary and hepatic vein orifices precluded complete baffling. This report describes an intraatrial baffle repair of anomalous systemic venous return without hepatic venous drainage. This resulted in good oxygenation postoperatively, with oxygen saturation ranging from 93% to 98%.

[Injury patterns and prophylaxis in inline skating].

PubMed

Jerosch, J; Heck, C

2005-05-01

Inline skating has become one of the fastest growing sports since its appearance in 1980. The increasing number of inline skaters has also led to a rising incidence of injuries. The most common injury is the distal fracture of the radius, which occurs in 50% of all fractures. There are several reasons for increasing serious injuries in inline skating. The majority of skaters do not wear proper protective equipment (helmet, elbow, knee and wrist protectors), however, many users can not handle their inline skates in dangerous situations. All skaters should take care by buying industrially tested inline skates and appropriate protective equipment; novice skaters should additionally attend special skating schools to learn skating, braking and the the correct falling techniques.

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 II...

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 II...

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 II...

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 II...

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 II...

Dispersant Effectiveness Of Heavy Fuel Oils Using The Baffled Flask Test

EPA Science Inventory

Dispersants have been widely used as a primary response measure for marine oil spills around the world. Recently, the U.S. Environmental Protection Agency (EPA) developed an improved laboratory dispersant testing protocol, called the Baffled Flask Test (BFT). The BFT protocol w...

Age group athletes in inline skating: decrease in overall and increase in master athlete participation in the longest inline skating race in Europe - the Inline One-Eleven.

PubMed

Teutsch, Uwe; Knechtle, Beat; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

2013-01-01

Participation and performance trends in age group athletes have been investigated in endurance and ultraendurance races in swimming, cycling, running, and triathlon, but not in long-distance inline skating. The aim of this study was to investigate trends in participation, age, and performance in the longest inline race in Europe, the Inline One-Eleven over 111 km, held between 1998 and 2009. The total number, age distribution, age at the time of the competition, and race times of male and female finishers at the Inline One-Eleven were analyzed. Overall participation increased until 2003 but decreased thereafter. During the 12-year period, the relative participation in skaters younger than 40 years old decreased while relative participation increased for skaters older than 40 years. The mean top ten skating time was 199 ± 9 minutes (range: 189-220 minutes) for men and 234 ± 17 minutes (range: 211-271 minutes) for women, respectively. The gender difference in performance remained stable at 17% ± 5% across years. To summarize, although the participation of master long-distance inline skaters increased, the overall participation decreased across years in the Inline One-Eleven. The race times of the best female and male skaters stabilized across years with a gender difference in performance of 17% ± 5%. Further studies should focus on the participation in the international World Inline Cup races.

Age group athletes in inline skating: decrease in overall and increase in master athlete participation in the longest inline skating race in Europe – the Inline One-Eleven

PubMed Central

Teutsch, Uwe; Knechtle, Beat; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

2013-01-01

Background Participation and performance trends in age group athletes have been investigated in endurance and ultraendurance races in swimming, cycling, running, and triathlon, but not in long-distance inline skating. The aim of this study was to investigate trends in participation, age, and performance in the longest inline race in Europe, the Inline One-Eleven over 111 km, held between 1998 and 2009. Methods The total number, age distribution, age at the time of the competition, and race times of male and female finishers at the Inline One-Eleven were analyzed. Results Overall participation increased until 2003 but decreased thereafter. During the 12-year period, the relative participation in skaters younger than 40 years old decreased while relative participation increased for skaters older than 40 years. The mean top ten skating time was 199 ± 9 minutes (range: 189–220 minutes) for men and 234 ± 17 minutes (range: 211–271 minutes) for women, respectively. The gender difference in performance remained stable at 17% ± 5% across years. Conclusion To summarize, although the participation of master long-distance inline skaters increased, the overall participation decreased across years in the Inline One-Eleven. The race times of the best female and male skaters stabilized across years with a gender difference in performance of 17% ± 5%. Further studies should focus on the participation in the international World Inline Cup races. PMID:23690697

Pressure letdown method and device for coal conversion systems

NASA Technical Reports Server (NTRS)

Kendal, J. M.; Walsh, J. V. (Inventor)

1983-01-01

In combination with a reactor for a coal utilization system, a pressure letdown device accepts from a reactor, a polyphase fluid at an entrance pressure and an entrance velocity, and discharges the fluid from the device at a discharge pressure substantially lower than the entrance pressure and at a discharge temperature and a discharge velocity substantially equal to the entrance temperature and entrance velocity. The device is characterized by a series of pressure letdown stages including several symmetrical baffles, disposed in coaxially nested alignment. In each baffle several ports or apertures of uniform dimensions are defined. The number of ports or apertures for each baffle plate is unique with respect to the number of ports or apertures defined in each of the other baffles. The mass rate of flow for each port is a function of the area of the port, the pressure of the fluid as applied to the port, and a common pressure ratio established across the ports.

Improved power efficiency for very-high-temperature solar-thermal-cavity receivers

DOEpatents

McDougal, A.R.; Hale, R.R.

1982-04-14

This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positiond in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained in the cavity; thus, high internal temperatues are attained.

Comparison of performance of shell-and-tube heat exchangers with conventional segmental baffles and continuous helical baffle

NASA Astrophysics Data System (ADS)

Ahmed, Asif; Ferdous, Imam Ul.; Saha, Sumon

2017-06-01

In the present study, three-dimensional numerical simulation of two shell-and-tube heat exchangers (STHXs) with conventional segmental baffles (STHXsSB) and continuous helical baffle (STHXsHB) is carried out and a comparative study is performed based on the simulation results. Both of the STHXs contain 37 tubes inside a 500 mm long and 200 mm diameter shell and mass flow rate of shell-side fluid is varied from 0.5 kg/s to 2 kg/s. At first, physical and mathematical models are developed and numerically simulated using finite element method (FEM). For the validation of the computational model, shell-side average nusselt number (Nus) is calculated from the simulation results and compared with the available experimental results. The comparative study shows that STHXsHB has 72-127% higher heat transfer coefficient per unit pressure drop compared to the conventional STHXsSB for the same shell-side mass flow rate. Moreover, STHXsHB has 59-63% lower shell-side pressure drop than STHXsSB.

Abatement of an aircraft exhaust plume using aerodynamic baffles.

PubMed

Bennett, Michael; Christie, Simon M; Graham, Angus; Garry, Kevin P; Velikov, Stefan; Poll, D Ian; Smith, Malcolm G; Mead, M Iqbal; Popoola, Olalekan A M; Stewart, Gregor B; Jones, Roderic L

2013-03-05

The exhaust jet from a departing commercial aircraft will eventually rise buoyantly away from the ground; given the high thrust/power (i.e., momentum/buoyancy) ratio of modern aero-engines, however, this is a slow process, perhaps requiring ∼ 1 min or more. Supported by theoretical and wind tunnel modeling, we have experimented with an array of aerodynamic baffles on the surface behind a set of turbofan engines of 124 kN thrust. Lidar and point sampler measurements show that, as long as the intervention takes place within the zone where the Coanda effect holds the jet to the surface (i.e., within about 70 m in this case), then quite modest surface-mounted baffles can rapidly lift the jet away from the ground. This is of potential benefit in abating both surface concentrations and jet blast downstream. There is also some modest acoustic benefit. By distributing the aerodynamic lift and drag across an array of baffles, each need only be a fraction of the height of a single blast fence.

Model-Scale Aerodynamic Performance Testing of Proposed Modifications to the NASA Langley Low Speed Aeroacoustic Wind Tunnel

NASA Technical Reports Server (NTRS)

Booth, Earl R., Jr.; Coston, Calvin W., Jr.

2005-01-01

Tests were performed on a 1/20th-scale model of the Low Speed Aeroacoustic Wind Tunnel to determine the performance effects of insertion of acoustic baffles in the tunnel inlet, replacement of the existing collector with a new collector design in the open jet test section, and addition of flow splitters to the acoustic baffle section downstream of the test section. As expected, the inlet baffles caused a reduction in facility performance. About half of the performance loss was recovered by addition the flow splitters to the downstream baffles. All collectors tested reduced facility performance. However, test chamber recirculation flow was reduced by the new collector designs and shielding of some of the microphones was reduced owing to the smaller size of the new collector. Overall performance loss in the facility is expected to be a 5 percent top flow speed reduction, but the facility will meet OSHA limits for external noise levels and recirculation in the test section will be reduced.

Power efficiency for very high temperature solar thermal cavity receivers

DOEpatents

McDougal, Allan R.; Hale, Robert R.

1984-01-01

This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positioned in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts infrared radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained in the cavity; thus, high internal temperatures are attained.

An analytical study of reduced-gravity propellant settling

NASA Technical Reports Server (NTRS)

Bradshaw, R. D.; Kramer, J. L.; Masica, W. J.

1974-01-01

Full-scale propellant reorientation flow dynamics for the Centaur D-1T fuel tank were analyzed. A computer code using the simplified marker and cell technique was modified to include the capability for a variable-grid mesh configuration. Use of smaller cells near the boundary, near baffles, and in corners provides improved flow resolution. Two drop tower model cases were simulated to verify program validity: one case without baffles, the other with baffles and geometry identical to Centaur D-1T. Flow phenomena using the new code successfully modeled drop tower data. Baffles are a positive factor in the settling flow. Two full-scale Centaur D-1T cases were simulated using parameters based on the Titan/Centaur proof flight. These flow simulations indicated the time to clear the vent area and an indication of time to orient and collect the propellant. The results further indicated the complexity of the reorientation flow and the long time period required for settling.

Acoustical properties of materials and muffler configurations for the 80 by 120 foot wind tunnel

NASA Technical Reports Server (NTRS)

Scharton, T. D.; Sneddon, M. D.

1977-01-01

Techniques for measuring the impedance of the muffler configurations and of porous plates with grazing flow were investigated and changes in the configuration parameters to enhance acoustic performance are explored. The feasibility of a pulse reflection technique for measuring the impedance of built-up structures in situ was demonstrated. A second technique involving the use of an open-end impedance tube with grazing flow was used to obtain detailed design data for the perforated plate configuration. Acoustic benefits associated with configuration changes such as curving the baffles, spacing and staggering baffle partitions, and techniques for alleviating baffle self-generated noise are described.

The variable magnetic baffle as a control device for Kaufman thrusters.

NASA Technical Reports Server (NTRS)

Poeschel, R. L.

1972-01-01

The variable magnetic baffle described in this paper aids in control of electron flow from the hollow cathode plasma into the main discharge region by augmenting the fringe magnetic field which impedes this electron flow in conventionally baffled Kaufman thrusters. A passive, low loss, and automatic control device is obtained by using the discharge current to excite the control winding. Used in conjunction with typical thruster control loops, stable operation has been obtained over a 10:1 throttling range with a 30 cm thruster. Discharge ignition and overcurrent recycling is also facilitated through use of this device in a permanent magnet thruster.

The influence of the earth radiation on space target detection system

NASA Astrophysics Data System (ADS)

Su, Xiaofeng; Chen, FanSheng; Cuikun, .; Liuyan, .

2017-05-01

In the view of space remote sensing such as satellite detection space debris detection etc. visible band is usually used in order to have the all-weather detection capability, long wavelength infrared (LWIR) detection is also an important supplement. However, in the tow wave band, the earth can be a very strong interference source, especially in the dim target detecting. When the target is close to the earth, especially the LEO target, the background radiation of the earth will also enter into the baffle, and became the stray light through reflection, the stray light can reduce the signal to clutter ratio (SCR) of the target and make it difficult to be detected. In the visible band, the solar albedo by the earth is the main clutter source while in the LWIR band the radiation of the earth is the main clutter source. So, in this paper, we establish the energy transformation from the earth background radiation to the detection system to assess the effects of the stray light. Firstly, we discretize the surface of the earth to different unit, and using MODTRAN to calculate the radiation of the discrete point in different light and climate conditions, then, we integral all the radiation which can reach the baffle in the same observation angles to get the energy distribution, finally, according the target energy and the non-uniformity of the detector, we can calculate the design requirement of the system stray light suppression, which provides the design basis for the optical system.

Effects of film injection angle on turbine vane cooling

NASA Technical Reports Server (NTRS)

Gauntner, J. W.

1977-01-01

Film ejection from discrete holes in the suction surface of a turbine vane was studied for hole axes (1) slanted 30 deg to the surface in the streamwise direction and (2) slanted 30 deg to the surface and 45 deg from the streamwise direction toward the hub. The holes were near the throat area in a five-row staggered array with 8-diameter spacing. Mass flux ratios were as high as 1.2. The data were obtained in an annular sector cascade at conditions where both the ratio of the boundary layer momentum thickness-to-hole diameter and the momentum thickness Reynolds number were typical of an advanced turbofan engine at both takeoff and cruise. Wall temperatures were measured downstream of each of the rows of holes. Results of this study are expressed as a comparison of cooling effectiveness between the in-line angle injection and the compound-angle injection as a function of mass flux ratio. These heat transfer results are also compared with the results of a referenced flow visualization study. Also included is a closed-form analytical solution for temperature within the film cooled wall.

Acute physiological responses to recreational in-line skating in young adults.

PubMed

Orepic, Paula; Mikulic, Pavle; Soric, Maroje; Ruzic, Lana; Markovic, Goran

2014-01-01

We examined the physiological responses to in-line skating exercise at self-selected paces in recreationally trained adults. Seven men and 10 women performed in-line skating exercise during which oxygen uptake (VO2) and heart rate (HR) were recorded continuously. Ratings of perceived exertion (RPE) and blood lactate concentration were also obtained at the end of exercise. Furthermore, subjects' peak VO2, peak HR, RPE and gas-exchange thresholds were determined in laboratory settings. The average exercise intensity during in-line skating was 90% of peak HR, 67% of peak VO2, 84% of HR reserve and 64% of VO2 reserve. When expressed as RPE and as metabolic equivalents (METs), the average exercise intensity was 13.1 RPE and 9.4 METs. Overall, these indicators of exercise intensity categorise in-line skating at self-selected paces as a vigorous physical activity. Notably, at similar VO2 values, significantly higher HR (174 ± 16 vs. 156 ± 6 bpm; p<0.001) and RPE (13.1 ± 1.4 vs. 11.7 ± 1.4; p=0.019) were observed for in-line skating compared with treadmill running. We conclude that 1. recreational in-line skating induces physiological responses that are sufficient for improving and maintaining cardiovascular fitness in healthy adults, 2. HR- and RPE-based methods for quantifying the exercise intensity during in-line skating may overestimate the actual metabolic load and 3. the derivation of exercise prescriptions for in-line skating should be preferably based on specific (i.e. in-line skating) graded exhaustive exercise test.

THE BAFFLED FLASK TEST FOR DISPERSANT EFFECTIVENESS: A ROUND ROBIN EVALUATION OF REPRODUCIBILITY AND REPEATABILITY

EPA Science Inventory

After two previous investigations demonstrated that the Baffled Flask Test (BFT) was an effective and reproducible method for screening the effectiveness of dispersant products in the laboratory, the USEPA decided that before the new protocol cold be considered for replacement of...

A new method named as Segment-Compound method of baffle design

NASA Astrophysics Data System (ADS)

Qin, Xing; Yang, Xiaoxu; Gao, Xin; Liu, Xishuang

2017-02-01

As the observation demand increased, the demand of the lens imaging quality rising. Segment- Compound baffle design method was proposed in this paper. Three traditional methods of baffle design they are characterized as Inside to Outside, Outside to Inside, and Mirror Symmetry. Through a transmission type of optical system, the four methods were used to design stray light suppression structure for it, respectively. Then, structures modeling simulation with Solidworks, CAXA, Tracepro, At last, point source transmittance (PST) curve lines were got to describe their performance. The result shows that the Segment- Compound method can inhibit stay light more effectively. Moreover, it is easy to active and without use special material.

Reflective baffle for BepiColombo mission

NASA Astrophysics Data System (ADS)

Rugi-Grond, E.; Weigel, T.; Herren, A.; Dominguez Calvo, M.; Krähenbühl, U.; Mouricaud, D.; Vayssade, H.

2017-11-01

The BepiColombo Spacecraft can't tolerate to absorb a major fraction of the off-axis sunlight through larger payload apertures. Fortunately, there are solutions to design baffles such that they reflect the incoming radiation back through the front aperture rather than absorbing it. A Design Study, sponsored by ESA and performed by Contraves Space together with SAGEM Défense Securité, has analysed the potential of various solutions and assessed the options to manufacture them. The selected configuration has been analysed in detail for the optical, mechanical and thermal performance as well as the impact on mass and power dissipation. The size of the baffle was adapted to the needs of the BepiColombo Laser Altimeter (BELA) payload.

Ultraviolet and visible BRDF data on spacecraft thermal control and optical baffle materials

NASA Technical Reports Server (NTRS)

Viehmann, W.; Predmore, R. E.

1987-01-01

Bidirectional scattering functions of numerous optical baffle materials and of spacecraft thermal control coatings and surfaces are presented. Measurements were made at 254 nm and at 633 nm. The coatings and surfaces include high-reflectance white paints, low-reflectance optical blacks, thermal control blankets, and various conversion coatings on aluminum.

Modeling of growth and laccase production by Pycnoporus sanguineus.

PubMed

Saat, Muhammad Naziz; Annuar, Mohamad Suffian Mohamad; Alias, Zazali; Chuan, Ling Tau; Chisti, Yusuf

2014-05-01

Production of extracellular laccase by the white-rot fungus Pycnoporus sanguineus was examined in batch submerged cultures in shake flasks, baffled shake flasks and a stirred tank bioreactor. The biomass growth in the various culture systems closely followed a logistic growth model. The production of laccase followed a Luedeking-Piret model. A modified Luedeking-Piret model incorporating logistic growth effectively described the consumption of glucose. Biomass productivity, enzyme productivity and substrate consumption were enhanced in baffled shake flasks relative to the cases for the conventional shake flasks. This was associated with improved oxygen transfer in the presence of the baffles. The best results were obtained in the stirred tank bioreactor. At 28 °C, pH 4.5, an agitation speed of 600 rpm and a dissolved oxygen concentration of ~25 % of air saturation, the laccase productivity in the bioreactor exceeded 19 U L(-1 )days(-1), or 1.5-fold better than the best case for the baffled shake flask. The final concentration of the enzyme was about 325 U L(-1).

Effect of Fin Passage Length on Optimization of Cylinder Head Cooling Fins

NASA Technical Reports Server (NTRS)

Siegel, R.; Graham, R. W.

1977-01-01

The heat transfer performance of baffled cooling fins on cylinder heads of small, air-cooled, general-aviation aircraft engines was analyzed to determine the potential for improving cooling fin design. Flow baffles were assumed to be installed tightly against the fin end edges, an ideal baffle configuration for guiding all flow between the fins. A rectangular flow passage is thereby formed between each set of two adjacent fins, the fin base surface, and the baffle. These passages extend around each side of the cylinder head, and the cooling air absorbs heat as it flows within them. For each flow passage length, the analysis was concerned with optimizing fin spacing and thickness to achieve the best heat transfer for each fin width. Previous literature has been concerned mainly with maximizing the local fin conductance and has not considered the heating of the gas in the flow direction, which leads to higher wall temperatures at the fin passage exits. If the fins are close together, there is a large surface area, but the airflow is restricted.

Nasal conchae function as aerodynamic baffles: Experimental computational fluid dynamic analysis in a turkey nose (Aves: Galliformes).

PubMed

Bourke, Jason M; Witmer, Lawrence M

2016-12-01

We tested the aerodynamic function of nasal conchae in birds using CT data from an adult male wild turkey (Meleagris gallopavo) to construct 3D models of its nasal passage. A series of digital "turbinectomies" were performed on these models and computational fluid dynamic analyses were performed to simulate resting inspiration. Models with turbinates removed were compared to the original, unmodified control airway. Results revealed that the four conchae found in turkeys, along with the crista nasalis, alter the flow of inspired air in ways that can be considered baffle-like. However, these baffle-like functions were remarkably limited in their areal extent, indicating that avian conchae are more functionally independent than originally hypothesized. Our analysis revealed that the conchae of birds are efficient baffles that-along with potential heat and moisture transfer-serve to efficiently move air to specific regions of the nasal passage. This alternate function of conchae has implications for their evolution in birds and other amniotes. Copyright © 2016 Elsevier B.V. All rights reserved.

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

A Computational Fluid Dynamics Study of Swirling Flow Reduction by using Anti-vortex Baffle

NASA Technical Reports Server (NTRS)

Yang, H. Q.; Peugeot, John W.; West, Jeff S..

2013-01-01

An anti-vortex baffle is a liquid propellant management device placed adjacent to an outlet of the propellant tank. Its purpose is to substantially reduce or eliminate the formation of free surface dip and vortex, as well as prevent vapor ingestion into the outlet, as the liquid drains out through the flight. To design an effective anti-vortex baffle, Computational Fluid Dynamic (CFD) simulations were undertaken for the NASA Ares I vehicle LOX tank subjected to the simulated flight loads with and without the anti-vortex baffle. The Six Degree-Of-Freedom (6- DOF) dynamics experienced by the Crew Launch Vehicle (CLV) during ascent were modeled by modifying the momentum equations in a CFD code to accommodate the extra body forces from the maneuvering in a non-inertial frame. The present analysis found that due to large moments, the CLV maneuvering has significant impact on the vortical flow generation inside the tank. Roll maneuvering and side loading due to pitch and yaw are shown to induce swirling flow. The vortical flow due to roll is symmetrical with respect to the tank centerline, while those induced by pitch and yaw maneuverings showed two vortices side by side. The study found that without the anti-vortex baffle, the swirling flow caused surface dip during the late stage of drainage and hence early vapor ingestion. The flow can also be non-uniform in the drainage pipe as the secondary swirling flow velocity component can be as high as 10% of the draining velocity. An analysis of the vortex dynamics shows that the swirling flow in the drainage pipe during the Upper Stage burn is mainly the result of residual vortices inside the tank due to conservation of angular momentum. The study demonstrated that the swirling flow in the drainage pipe can be effectively suppressed by employing the anti-vortex baffle.

A Computational Fluid Dynamics Study of Swirling Flow Reduction by Using Anti-Vortex Baffle

NASA Technical Reports Server (NTRS)

Yang, H. Q.; Peugeot, John W.; West, Jeff S.

2017-01-01

An anti-vortex baffle is a liquid propellant management device placed adjacent to an outlet of the propellant tank. Its purpose is to substantially reduce or eliminate the formation of free surface dip and vortex, as well as prevent vapor ingestion into the outlet, as the liquid drains out through the flight. To design an effective anti-vortex baffle, Computational Fluid Dynamic (CFD) simulations were undertaken for the NASA Ares I vehicle LOX tank subjected to the simulated flight loads with and without the anti-vortex baffle. The Six Degree-Of-Freedom (6-DOF) dynamics experienced by the Crew Launch Vehicle (CLV) during ascent were modeled by modifying the momentum equations in a CFD code to accommodate the extra body forces from the maneuvering in a non-inertial frame. The present analysis found that due to large moments, the CLV maneuvering has a significant impact on the vortical flow generation inside the tank. Roll maneuvering and side loading due to pitch and yaw are shown to induce swirling flow. The vortical flow due to roll is symmetrical with respect to the tank centerline, while those induced by pitch and yaw maneuverings showed two vortices side by side. The study found that without the anti-vortex baffle, the swirling flow caused surface dip during the late stage of drainage and hence early vapor ingestion. The flow can also be non-uniform in the drainage pipe as the secondary swirling flow velocity component can be as high as 10% of the draining velocity. An analysis of the vortex dynamics shows that the swirling flow in the drainage pipe during the Upper Stage burn is mainly the result of residual vortices inside the tank due to the conservation of angular momentum. The study demonstrated that the swirling flow in the drainage pipe can be effectively suppressed by employing the anti-vortex baffle.

Use of protective equipment by in-line skaters: an observational study

PubMed Central

Beirness, D; Foss, R; Desmond, K

2001-01-01

Objective—To determine the extent of protective equipment use (that is, helmets, wrist guards, elbow pads, knee pads) in a representative sample of in-line skaters. Setting—Fifteen municipalities throughout the province of British Columbia. Method—A province-wide observational survey was conducted in the summer of 1999. Skaters were observed at four types of sites (commuter, recreational, neighbourhood, general community) in 15 municipalities to provide a representative sample of in-line skaters. Results—The observed use of protective equipment by the 877 in-line skaters was relatively low: wrist guards 25%, helmets 13%, elbow pads 14%, and knee pads 10%. Conclusion—Despite the availability of relatively inexpensive protective equipment, few in-line skaters take advantage of the opportunity to protect themselves from injury. Policies and programs that serve to increase the use of protective equipment by in-line skaters are needed to help reduce the frequency of skating related injuries. PMID:11289536

On the effective field theory of heterotic vacua

NASA Astrophysics Data System (ADS)

McOrist, Jock

2018-04-01

The effective field theory of heterotic vacua that realise [InlineEquation not available: see fulltext.] preserving N{=}1 supersymmetry is studied. The vacua in question admit large radius limits taking the form [InlineEquation not available: see fulltext.], with [InlineEquation not available: see fulltext.] a smooth threefold with vanishing first Chern class and a stable holomorphic gauge bundle [InlineEquation not available: see fulltext.]. In a previous paper we calculated the kinetic terms for moduli, deducing the moduli metric and Kähler potential. In this paper, we compute the remaining couplings in the effective field theory, correct to first order in {α ^{\\backprime } }. In particular, we compute the contribution of the matter sector to the Kähler potential and derive the Yukawa couplings and other quadratic fermionic couplings. From this we write down a Kähler potential [InlineEquation not available: see fulltext.] and superpotential [InlineEquation not available: see fulltext.].

Battle Keeps Solar Energy in Receiver

NASA Technical Reports Server (NTRS)

Mcdougal, A. R.; Hale, R. R.

1982-01-01

Mirror structure in solar concentrator reduces heat loss by reflection and reradiation. Baffle reflects entering rays back and forth in solar-concentrator receiver until they reach heat exchanger. Similarly, infrared energy reradiated by heat exchanger is prevented from leaving receiver. Surfaces of baffle and inside wall of receiver are polished and highly reflective at solar and infrared wavelengths.

Electron diffusion through the baffle aperture of a hollow cathode thruster

NASA Technical Reports Server (NTRS)

Brophy, J. R.; Wilbur, P. J.

1979-01-01

The use of a hollow cathode in place of an oxide cathode to increase thruster operating lifetimes requires, among other things, the addition of a baffle to restrict the flow of electrons from the hollow cathode. A theoretical model is developed which relates the baffle aperture area of a hollow-cathode thruster to the magnetic flux density and plasma properties in the aperture region, with the result that this model could be used as an aid in thruster design. Extensive Langmuir probing is undertaken to verify the validity of the model and demonstrate its capability. It is shown that the model can be used to calculate the aperture area required to effect discharge operation at a specified discharge voltage and arc current.

Single bi-temperature thermal storage tank for application in solar thermal plant

DOEpatents

Litwin, Robert Zachary; Wait, David; Lancet, Robert T.

2017-05-23

Thermocline storage tanks for solar power systems are disclosed. A thermocline region is provided between hot and cold storage regions of a fluid within the storage tank cavity. One example storage tank includes spaced apart baffles fixed relative to the tank and arranged within the thermocline region to substantially physically separate the cavity into hot and cold storage regions. In another example, a flexible baffle separated the hot and cold storage regions and deflects as the thermocline region shifts to accommodate changing hot and cold volumes. In yet another example, a controller is configured to move a baffle within the thermocline region in response to flow rates from hot and cold pumps, which are used to pump the fluid.

Catalytic reactor with improved burner

DOEpatents

Faitani, Joseph J.; Austin, George W.; Chase, Terry J.; Suljak, George T.; Misage, Robert J.

1981-01-01

To more uniformly distribute heat to the plurality of catalyst tubes in a catalytic reaction furnace, the burner disposed in the furnace above the tops of the tubes includes concentric primary and secondary annular fuel and air outlets. The fuel-air mixture from the primary outlet is directed towards the tubes adjacent the furnace wall, and the burning secondary fuel-air mixture is directed horizontally from the secondary outlet and a portion thereof is deflected downwardly by a slotted baffle toward the tubes in the center of the furnace while the remaining portion passes through the slotted baffle to another baffle disposed radially outwardly therefrom which deflects it downwardly in the vicinity of the tubes between those in the center and those near the wall of the furnace.

Predictors of injury among adult recreational in-line skaters: a multicity study.

PubMed Central

Seldes, R M; Grisso, J A; Pavell, J R; Berlin, J A; Tan, V; Bowman, B; Kinman, J L; Fitzgerald, R H

1999-01-01

OBJECTIVES: This study examined risk factors for injury, injury prevalence, safety gear use, and skating habits of adult recreational in-line skaters. METHODS: Randomly selected in-line skaters in 6 major US cities were interviewed. RESULTS: Only 6% of skaters consistently wore all 4 recommended types of safety gear. Skaters with greater skating experience were more likely to perform tricks, wear less safety gear, and sustain an injury. CONCLUSION: More experienced adult recreational in-line skaters are at increased risk for injury. Safety gear use in alarmingly low in adult recreational in-line skaters, especially experienced skaters. Safe skating education programs should consider targeting this newly recognized at-risk skating population. PMID:9949756

Predictor variables of performance in recreational male long-distance inline skaters.

PubMed

Knechtle, Beat; Knechtle, Patrizia; Rüst, Christoph Alexander; Senn, Oliver; Rosemann, Thomas; Lepers, Romuald

2011-06-01

We investigated the associations between selected anthropometric and training characteristics with race time in 84 recreational male long-distance inline skaters at the longest inline marathon in Europe, the 'Inline One-eleven' over 111 km in Switzerland, using bi- and multivariate analysis. The mean (s) race time was 264 (41) min. The bivariate analysis showed that age (r = 0.30), body mass (r = 0.42), body mass index (r = 0.35), circumference of upper arm (r = 0.32), circumference of thigh (r = 0.29), circumference of calf (r = 0.38), skin-fold of thigh (r = 0.22), skin-fold of calf (r = 0.27), the sum of skin-folds (r = 0.43), percent body fat (r = 0.45), duration per training unit in inline skating (r = 0.33), and speed during training (r = -0.46) were significantly and positively correlated to race time. Stepwise multiple regression showed that duration per training unit (P = 0.003), age (P = 0.029) and percent body fat (P = 0.016) were the best correlated with race time. Race time in a long-distance inline race such as the 'Inline One-eleven' over 111 km with a mean race time of ∼260 min might be predicted by the following equation (r(2) = 0.41): Race time (min) = 114.91 + 0:51* (duration per training unit, min) + 0:85* (age, years) +3:78* (body fat, %) for recreational long-distance inline skaters.

In-Line Filtration Reduces Postoperative Venous Peripheral Phlebitis Associated With Cannulation: A Randomized Clinical Trial.

PubMed

Villa, Gianluca; Chelazzi, Cosimo; Giua, Rosa; Tofani, Lorenzo; Zagli, Giovanni; Boninsegni, Paolo; Pinelli, Fulvio; De Gaudio, A Raffaele; Romagnoli, Stefano

2018-04-23

Peripheral venous cannulation is an everyday practice of care for patients undergoing anesthesia and surgery. Particles infused with intravenous fluids (eg, plastic/glass/drugs particulate) contribute to the pathogenesis of peripheral phlebitis. The aim of this study is to demonstrate the efficacy of in-line filtration in reducing the incidence of postoperative phlebitis associated with peripheral short-term vascular access. In this controlled trial, 268 surgical patients were randomly assigned to in-line filtration and standard care (NCT03193827). The incidence of phlebitis (defined as visual infusion phlebitis [VIP] score, ≥2) within 48 hours was compared between the 2 groups, as well as the onset and severity of phlebitis and the reasons for removal of the cannula. The lifespan of venous cannulae was compared for the in-line filter and no-filter groups through a Kaplan-Meier curve. The incidence of phlebitis within 48 hours postoperatively was 2.2% and 26.9% (difference, 25% [95% confidence interval {CI}, 12%-36%]; odds ratio, 0.05 [0.01-0.15]), respectively, for the in-line filter and no-filter groups (P < .001). From 24 to 96 hours postoperatively, patients in the no-filter group had higher VIP scores than those in in-line filter group (P < .001). Venous cannulae in the in-line filter group exhibited prolonged lifespan compared to those in the no-filter group (P = .01). In particular, 64 (47.8%) of cannulae in the in-line filter group and 56 (41.8%) of those in the no-filter group were still in place at 96 hours postoperatively. At the same time point, patients with a VIP score <3 were 100% in the in-line filter group and only 50% for the no-filter group. In-line filtration was a protective factor for postoperative phlebitis (hazard ratio, 0.05 [95% CI, 0.014-0.15]; P < .0001) and cannula removal (hazard ratio, 0.7 [95% CI, 0.52-0.96]; P = .02). In-line filtration has a protective effect for postoperative phlebitis and prolongs cannula lifespan during peripheral venous cannulation in surgical patients.

Automatic coolant flow control device for a nuclear reactor assembly

DOEpatents

Hutter, E.

1984-01-27

A device which controls coolant flow through a nuclear reactor assembly comprises a baffle means at the exit end of said assembly having a plurality of orifices, and a bimetallic member in operative relation to the baffle means such that at increased temperatures said bimetallic member deforms to unblock some of said orifices and allow increased coolant flow therethrough.

Automatic coolant flow control device for a nuclear reactor assembly

DOEpatents

Hutter, Ernest

1986-01-01

A device which controls coolant flow through a nuclear reactor assembly comprises a baffle means at the exit end of said assembly having a plurality of orifices, and a bimetallic member in operative relation to the baffle means such that at increased temperatures said bimetallic member deforms to unblock some of said orifices and allow increased coolant flow therethrough.

Sensing performance analysis on Fano resonance of metallic double-baffle contained MDM waveguide coupled ring resonator

NASA Astrophysics Data System (ADS)

Chen, Ying; Luo, Pei; Liu, Xiaofei; Di, Yuanjian; Han, Shuaitao; Cui, Xingning; He, Lei

2018-05-01

Based on the transmission property and the photon localization characteristic of the surface plasmonic sub-wavelength structure, a metallic double-baffle contained metal-dielectric-metal (MDM) waveguide coupled ring resonator is proposed. Like the electromagnetically induced transparency (EIT), the Fano resonance can be achieved by the interference between the metallic double-baffle resonator and the ring resonator. Based on the coupled mode theory, the transmission property is analyzed. Through the numerical simulation by the finite element method (FEM), the quantitative analysis on the influences of the radius R of the ring and the coupling distance g between the metallic double-baffle resonator and the ring resonator for the figure of merit (FOM) is performed. And after the structure parameter optimization, the sensing performance of the waveguide structure is discussed. The simulation results show that the FOM value of the optimized structure can attain to 5.74 ×104 and the sensitivity of resonance wavelength with refractive index drift is about 825 nm/RIU. The range of the detected refractive index is suitable for all gases. The waveguide structure can provide effective theoretical references for the design of integrated plasmonic devices.

Device for producing a fluid stream of varying composition

DOEpatents

Moss, Owen R.; Clark, Mark L.; Rossignol, E. John

1982-01-01

A device for producing a fluid stream of varying composition comprises a chamber having an inlet at one end and outlet at the other. Between the inlet and outlet there are substantially planar pans or baffles positioned normal to the bulk flow of fluid between the inlet and the outlet. These pans are arranged in pairs. Each pan, except those of the pair most remote from the inlet, is spaced from the walls of the chamber to permit air to flow past it. The pans of each pair are also spaced from each other, in a direction parallel to their planes, leaving an empty space along the mid-plane of the chamber. This produces a circulation and mixing of fluid between the pairs of pans or baffles. A secondary stream of fluid is introduced between two pairs of baffles in the intermediate portion of the chamber, so that the composition of the fluid is different in the portion adjacent to the outlet and the portion adjacent to the inlet. In a specific embodiment, the device is an exposure chamber for experimental animals, and the pans or baffles are catch pans for excrement.

Optimizing the longitudinal and transverse electroosmotic pumping in a rectangular channel with horizontal baffle plates

NASA Astrophysics Data System (ADS)

Lai, Anison K. R.; Chang, Chien-Cheng; Wang, Chang-Yi

2018-04-01

This paper presents a continued study to our previous work on electroosmotic (EO) flow in a channel with vertical baffle plates by further investigating EO flow through an array of baffle plates arranged in parallel to the channel walls. The flow may be driven either in the direction along or in the direction transverse to the plates, thus distinguishing the longitudinal EO pumping (LEOP) and the transverse EO pumping (TEOP). In both types of EO pumping, it is more interesting to examine the cases when the baffle plates develop a higher zeta potential (denoted by α) than that on the channel walls (β). This semi-analytical study enables us to compare between LEOP and TEOP in the pumping efficiency under similar conditions. The TEOP case is more difficult to solve due to the higher order governing partial differential equations caused by the induced non-uniform pressure gradient distribution. In particular, we examine how the EO pumping rates deviate from those predicted by the Helmholtz-Smoluchowski velocity and illustrate the general trend of optimizing the EO pumping rates with respect to the physical and geometric parameters involved.

Process and apparatus, mainly for burning agricultural plant refuse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bela, B.; Geza, G.; Istvan, C.

1984-05-22

Freshly harvested agricultural materials having a moisture content no greater than 45% by weight are burned in a furnace in which the housing thereof is divided into preburning and afterburning spaces by a baffle wall. The preburning space contains a horizontally arranged first grating adjacent the baffle wall and a second grating adjacent the first and inclined upwardly therefrom and juxtaposed with an inlet in the housing for the introduction at a constant rate of the materials onto the inclined grating, the upper portion of which is fed by a first portion of primary air for the removal of moisturemore » from the materials, while a lower portion of the inclined grating is fed with a second portion of primary air for the air-deficient burning of the dried materials and the production of combustible gases. The horizontal grating is fed with a third portion of primary air for driving the combustible gases along the baffle wall, which acts to deflect the gases in a counterflow to the flow of the materials, the gases mixing with secondary air introduced through at least one air inlet formed in the baffle wall, the mixture being burned completely in the afterburning space.« less

BaffleText: a Human Interactive Proof

NASA Astrophysics Data System (ADS)

Chew, Monica; Baird, Henry S.

2003-01-01

Internet services designed for human use are being abused by programs. We present a defense against such attacks in the form of a CAPTCHA (Completely Automatic Public Turing test to tell Computers and Humans Apart) that exploits the difference in ability between humans and machines in reading images of text. CAPTCHAs are a special case of 'human interactive proofs,' a broad class of security protocols that allow people to identify themselves over networks as members of given groups. We point out vulnerabilities of reading-based CAPTCHAs to dictionary and computer-vision attacks. We also draw on the literature on the psychophysics of human reading, which suggests fresh defenses available to CAPTCHAs. Motivated by these considerations, we propose BaffleText, a CAPTCHA which uses non-English pronounceable words to defend against dictionary attacks, and Gestalt-motivated image-masking degradations to defend against image restoration attacks. Experiments on human subjects confirm the human legibility and user acceptance of BaffleText images. We have found an image-complexity measure that correlates well with user acceptance and assists in engineering the generation of challenges to fit the ability gap. Recent computer-vision attacks, run independently by Mori and Jitendra, suggest that BaffleText is stronger than two existing CAPTCHAs.

Liquid oxygen sloshing in Space Shuttle External Tank

NASA Technical Reports Server (NTRS)

Kannapel, M. D.; Przekwas, A. J.; Singhal, A. K.; Costes, N. C.

1987-01-01

This paper describes a numerical simulation of the hydrodynamics within the liquid oxygen tank of the Space Shuttle External Tank during liftoff. Before liftoff, the tank is filled with liquid oxygen (LOX) to approximately 97 percent with the other 3 percent containing gaseous oxygen (GOX) and helium. During liftoff, LOX is drained from the bottom of the tank, and GOX is pumped into the tank's ullage volume. There is a delay of several seconds before the GOX reaches the tank which causes the ullage pressure to decrease for several seconds after liftoff; this pressure 'slump' is a common phenomenon in rocket propulsion. When four slosh baffles were removed from the tank, the ullage gas pressure dropped more rapidly than in all previous flights. The purpose of this analysis was to determine whether the removal of the baffles could have caused the increased pressure 'slump' by changing the LOX surface dynamics. The results show that the LOX surface undergoes very high vertical accelerations (up to 5 g) and, therefore, splashing almost certainly occurs. The number of baffles does not affect the surface if the structural motion is assumed; but, the number of baffles may affect the structural motion of the tank.

Sparsity-based multi-height phase recovery in holographic microscopy

NASA Astrophysics Data System (ADS)

Rivenson, Yair; Wu, Yichen; Wang, Hongda; Zhang, Yibo; Feizi, Alborz; Ozcan, Aydogan

2016-11-01

High-resolution imaging of densely connected samples such as pathology slides using digital in-line holographic microscopy requires the acquisition of several holograms, e.g., at >6-8 different sample-to-sensor distances, to achieve robust phase recovery and coherent imaging of specimen. Reducing the number of these holographic measurements would normally result in reconstruction artifacts and loss of image quality, which would be detrimental especially for biomedical and diagnostics-related applications. Inspired by the fact that most natural images are sparse in some domain, here we introduce a sparsity-based phase reconstruction technique implemented in wavelet domain to achieve at least 2-fold reduction in the number of holographic measurements for coherent imaging of densely connected samples with minimal impact on the reconstructed image quality, quantified using a structural similarity index. We demonstrated the success of this approach by imaging Papanicolaou smears and breast cancer tissue slides over a large field-of-view of ~20 mm2 using 2 in-line holograms that are acquired at different sample-to-sensor distances and processed using sparsity-based multi-height phase recovery. This new phase recovery approach that makes use of sparsity can also be extended to other coherent imaging schemes, involving e.g., multiple illumination angles or wavelengths to increase the throughput and speed of coherent imaging.

Experimental Investigation on Effect of Fin Shape on the Thermal-Hydraulic Performance of Compact Fin-and-Tube Heat Exchangers

NASA Astrophysics Data System (ADS)

Moorthy, P.; Oumer, A. N.; Ishak, M.

2018-03-01

The aim of this paper is to investigate the effect of fin shapes on the performance of compact finned flat tube heat exchangers. Three types of fin shapes namely plain, wavy, and rectangular grooved fins attached to three by three arrays of flat tube banks were considered. Moreover, the tubes were deployed in in-line and staggered arrangements. In addition to the fin shapes, the air velocity and the tube inclination angles were varied and the thermal-hydraulic performance was analysed. On the other hand, the temperatures at the tube surfaces were kept constant to produce constant heat flux throughout the study. The results showed that as flowrate increases, the heat transfer increases, however, the friction factor decreases. Staggered arrangement produces higher heat transfer and friction factor than inline fin. Moreover, the rectangular fin is the best in terms of high heat transfer however the drawback of high friction factor leads the fin to have the least efficiency of all. On the other hand, plain fin had the least heat transfer performance however the highest efficiency was achieved. Therefore, plain fin should be used when efficiency is prioritized and rectangular fin when high heat transfer is desired.

Technology demonstration for reducing mercury emissions from small-scale gold refining facilities.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habegger, L. J.; Fernandez, L. E.; Engle, M.

2008-06-30

Gold that is brought from artisanal and small-scale gold mining areas to gold shops for processing and sale typically contains 5-40% mercury. The uncontrolled removal of the residual mercury in gold shops by using high-temperature evaporation can be a significant source of mercury emissions in urban areas where the shops are located. Emissions from gold shop hoods during a burn can exceed 1,000 mg/m{sup 3}. Because the saturation concentration of mercury vapor at operating temperatures at the hood exhaust is less than 100 mg/m{sup 3}, the dominant component of the exhaust is in the form of aerosol or liquid particles.more » The U.S. Environmental Protection Agency (EPA), with technical support from Argonne National Laboratory (Argonne), has completed a project to design and test a technology to remove the dominant aerosol component in the emissions from gold shops. The objective was to demonstrate a technology that could be manufactured at low cost and by using locally available materials and manufacturing capabilities. Six prototypes designed by Argonne were locally manufactured, installed, and tested in gold shops in Itaituba and Creporizao, Brazil. The initial prototype design incorporated a pebble bed as the media for collecting the mercury aerosols, and a mercury collection efficiency of over 90% was demonstrated. Though achieving high efficiencies, the initial prototype was determined to have practical disadvantages such as excessive weight, a somewhat complex construction, and high costs (>US$1,000). To further simplify the construction, operation, and associated costs, a second prototype design was developed in which the pebble bed was replaced with slotted steel baffle plates. The system was designed to have flexibility for installation in various hood configurations. The second prototype with the baffle plate design was installed and tested in several different hood/exhaust systems to determine the optimal installation configuration. The significance of coagulation and collection of the mercury aerosols in exhaust ducts, which is dependent on the hood and collector configuration, was also evaluated. Prototype demonstration tests verified the theoretical basis for mercury aerosol capture that can be used to optimize the baffle plate design, flow rates, and hood exhaust ducts and plenum to achieve 80% or higher removal efficiencies. Results indicated that installation configuration significantly influences a system's capture efficiency. Configurations that retained existing inlet ducts resulted in system efficiencies of more than 80%, whereas installation configurations without inlet ducts significantly reduced capture efficiency. As an alternative to increasing the volume of inlet ducts, the number of baffle plates in the system baffle assembly could be doubled to increase efficiency. Recommended installation and operation procedures were developed on the basis of these results. A water-based mercury capture system developed in Indonesia for installation in smaller shops was also tested and shown to be effective for certain applications. The cost of construction and installation of the baffle plate prototype was approximately US$400. These costs were reported as acceptable by local gold shop owners and government regulators, and were significantly lower than the cost of an alternate charcoal/copper mesh mercury filter available in the region, which costs about US$10,000. A sampling procedure that consists of a particle filter combined with a vapor analyzer was demonstrated as an effective procedure for analyzing both the aerosol and vapor components of the mercury concentrations. Two key findings for enhancing higher mercury collection were identified. First, the aerosol/vapor mercury emissions must be given sufficient time for the mercury particles to coagulate to a size that can be readily captured by the baffle plates. An interval of at least 6 seconds of transit time between the point of evaporation and contact with the slotted baffle plates is recommended. Some particles will also deposit in the exhaust ducts between the point of evaporation and the baffle plates. Second, the slots in the baffle plates create jets that force the mercury particles to impinge and adhere on downstream surfaces. The baffle plates should closely follow the designs developed for this system to be most effective.« less

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

USDA-ARS?s Scientific Manuscript database

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...

Age, training, and previous experience predict race performance in long-distance inline skaters, not anthropometry.

PubMed

Knechtle, Beat; Knechtle, Patrizia; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

2012-02-01

The association of characteristics of anthropometry, training, and previous experience with race time in 84 recreational, long-distance, inline skaters at the longest inline marathon in Europe (111 km), the Inline One-eleven in Switzerland, was investigated to identify predictor variables for performance. Age, duration per training unit, and personal best time were the only three variables related to race time in a multiple regression, while none of the 16 anthropometric variables were related. Anthropometric characteristics seem to be of no importance for a fast race time in a long-distance inline skating race in contrast to training volume and previous experience, when controlled with covariates. Improving performance in a long-distance inline skating race might be related to a high training volume and previous race experience. Also, doing such a race requires a parallel psychological effort, mental stamina, focus, and persistence. This may be reflected in the preparation and training for the event. Future studies should investigate what motivates these athletes to train and compete.

Bidirectional reflectance distribution function of the Infrared Astronomical Satellite solar-shield material

NASA Technical Reports Server (NTRS)

Hubbs, J. E.; Nofziger, M. J.; Bartell, F. O.; Wolfe, W. L.; Brooks, L. D.

1982-01-01

The Infrared Astronomical Satellite (IRAS) telescope has an outer shield on it which is used to reduce the amount of thermal radiation that enters the telescope. The shield forms the first part of the baffle structure which reduces the photon incidence on the focal plane. It was, therefore, necessary to model this structure for scattering, and a required input for such modeling is the scattering characteristic of this surface. Attention is given to the measurement of the bidirectional reflectance distribution function (BRDF), the reflected radiance divided by the incident irradiance at 10.6 micrometers, 118 micrometers, and at several angles of incidence. Visual observation of the gold sample shows that there are striations which line up in a single direction. The data were, therefore, taken with the sample oriented in each of two directions.

Modeling the Restraint of Liquid Jets by Surface Tension in Microgravity

NASA Technical Reports Server (NTRS)

Chato, David J.; Jacqmim, David A.

2001-01-01

An axisymmetric phase field model is developed and used to model surface tension forces on liquid jets in microgravity. The previous work in this area is reviewed and a baseline drop tower experiment selected 'for model comparison. A mathematical model is developed which includes a free surface. a symmetric centerline and wall boundaries with given contact angles. The model is solved numerically with a compact fourth order stencil on a equally spaced axisymmetric grid. After grid convergence studies, a grid is selected and all drop tower tests modeled. Agreement was assessed by comparing predicted and measured free surface rise. Trend wise agreement is good but agreement in magnitude is only fair. Suspected sources of disagreement are suspected to be lack of a turbulence model and the existence of slosh baffles in the experiment which were not included in the model.

System for the measurement of ultra-low stray light levels. [determining the adequacy of large space telescope systems

NASA Technical Reports Server (NTRS)

Wyman, C. L.; Griner, D. B.; Hurd, W. A.; Shelton, G. B.; Hunt, G. H.; Fannin, B. B.; Brealt, R. P.; Hawkins, C. A. (Inventor)

1978-01-01

An apparatus is described for measuring the effectiveness of stray light suppression light shields and baffle arrangements used in optical space experiments and large space telescopes. The light shield and baffle arrangement and a telescope model are contained in a vacuum chamber. A source of short, high-powered light energy illuminates portions of the light shield and baffle arrangement and reflects a portion of same to a photomultiplier tube by virtue of multipath scattering. The resulting signal is transferred to time-channel electronics timed by the firing of the high energy light source allowing time discrimination of the signal thereby enabling the light scattered and suppressed by the model to be distinguished from the walls and holders around the apparatus.

Development of a High-Performance Fin-and-Tube Heat Exchanger with Vortex Generators for a Vending Machine

NASA Astrophysics Data System (ADS)

Iwasaki, Masamichi; Saito, Hiroshi; Mochizuki, Sadanari; Murata, Akira

The effect of delta-wing-vortex generators (combination of a delta wing and a delta winglet pair) on the heat transfer performance of fin-and-tube heat exchangers for vending machines has been investegated. Flow visualizations, numerical simulations and heat transfer experiments were conducted to find an optimum geometrical shape and arrangement of the vortex generators. Maximum heat transfer enhancement was achieved by the combination of (a) the delta wing with the apex angle of 86 degrees and (b) the delta winglet pair with the inline angle of 45 degrees. In relatively low Reynolds number range, about 40 % increase in heat transfer coefficient was attained with the above mentioned combination of the vortex generators compared to the ordinary heat exchangers with plain fins. It was revealed that the heat transfer enhancement was attributed to (1) the longitudinal vortexes generated by the delta wing and (2) the reduction of wake area behind the tube. It was also found that an increase in the apex angle of the delta wing brought about heat transfer enhancement, and the scale as well as the streggth of the induced longitudinal vortices played an important role in the heat transfer performance.

BioXTAS RAW: improvements to a free open-source program for small-angle X-ray scattering data reduction and analysis.

PubMed

Hopkins, Jesse Bennett; Gillilan, Richard E; Skou, Soren

2017-10-01

BioXTAS RAW is a graphical-user-interface-based free open-source Python program for reduction and analysis of small-angle X-ray solution scattering (SAXS) data. The software is designed for biological SAXS data and enables creation and plotting of one-dimensional scattering profiles from two-dimensional detector images, standard data operations such as averaging and subtraction and analysis of radius of gyration and molecular weight, and advanced analysis such as calculation of inverse Fourier transforms and envelopes. It also allows easy processing of inline size-exclusion chromatography coupled SAXS data and data deconvolution using the evolving factor analysis method. It provides an alternative to closed-source programs such as Primus and ScÅtter for primary data analysis. Because it can calibrate, mask and integrate images it also provides an alternative to synchrotron beamline pipelines that scientists can install on their own computers and use both at home and at the beamline.

Purification, crystallization, small-angle X-ray scattering and preliminary X-ray diffraction analysis of the SH2 domain of the Csk-homologous kinase.

PubMed

Gunn, Natalie J; Gorman, Michael A; Dobson, Renwick C J; Parker, Michael W; Mulhern, Terrence D

2011-03-01

The C-terminal Src kinase (Csk) and Csk-homologous kinase (CHK) are endogenous inhibitors of the proto-oncogenic Src family of protein tyrosine kinases (SFKs). Phosphotyrosyl peptide binding to their Src-homology 2 (SH2) domains activates Csk and CHK, enhancing their ability to suppress SFK signalling; however, the detailed mechanistic basis of this activation event is unclear. The CHK SH2 was expressed in Escherichia coli and the purified protein was characterized as monomeric by synchrotron small-angle X-ray scattering in-line with size-exclusion chromatography. The CHK SH2 crystallized in 0.2 M sodium bromide, 0.1 M bis-Tris propane pH 6.5 and 20% polyethylene glycol 3350 and the best crystals diffracted to ∼1.6 Å resolution. The crystals belonged to space group P2, with unit-cell parameters a=25.8, b=34.6, c=63.2 Å, β=99.4°.

Numerical exploration of non-axisymmetric divertor closure in the small angle slot (SAS) divertor at DIII-D

NASA Astrophysics Data System (ADS)

Frerichs, Heinke; Schmitz, Oliver; Covele, Brent; Guo, Houyang; Hill, David; Feng, Yuhe

2017-10-01

In the Small Angle Slot (SAS) divertor in DIII-D, the combination of misaligned slot structure and non-axisymmetric perturbations to the magnetic field causes the strike point to vary radially along the divertor slot and even leave it at some toroidal locations. This effect essentially introduces an opening in the divertor slot from where recycling neutrals can easily escape, and thereby degrade performance of the slot divertor. This effect has been approximated by a finite gap in the divertor baffle. Simulations with EMC3-EIRENE show that a toroidally localized loss of divertor closure can result in non-axisymmetric divertor densities and temperatures. This introduces a density window of 10-15% on top of the nominal threshold separatrix density during which a non-axisymmetric onset of local detachment occurs, initially leaving the gap and up to 60 deg beyond that still attached. Conversely, the impact of such toroidally localized divertor perturbations on the toroidal symmetry of midplane separatrix conditions is small. This work has been funded by the U.S. Department of Energy under Early Career Award Grant DE-SC0013911, and Grant DE-FC02-04ER54698.

The directivity of the sound radiation from panels and openings.

PubMed

Davy, John L

2009-06-01

This paper presents a method for calculating the directivity of the radiation of sound from a panel or opening, whose vibration is forced by the incidence of sound from the other side. The directivity of the radiation depends on the angular distribution of the incident sound energy in the room or duct in whose wall or end the panel or opening occurs. The angular distribution of the incident sound energy is predicted using a model which depends on the sound absorption coefficient of the room or duct surfaces. If the sound source is situated in the room or duct, the sound absorption coefficient model is used in conjunction with a model for the directivity of the sound source. For angles of radiation approaching 90 degrees to the normal to the panel or opening, the effect of the diffraction by the panel or opening, or by the finite baffle in which the panel or opening is mounted, is included. A simple empirical model is developed to predict the diffraction of sound into the shadow zone when the angle of radiation is greater than 90 degrees to the normal to the panel or opening. The method is compared with published experimental results.

Stray light lessons learned from the Mars reconnaissance orbiter's optical navigation camera

NASA Astrophysics Data System (ADS)

Lowman, Andrew E.; Stauder, John L.

2004-10-01

The Optical Navigation Camera (ONC) is a technical demonstration slated to fly on NASA"s Mars Reconnaissance Orbiter in 2005. Conventional navigation methods have reduced accuracy in the days immediately preceding Mars orbit insertion. The resulting uncertainty in spacecraft location limits rover landing sites to relatively safe areas, away from interesting features that may harbor clues to past life on the planet. The ONC will provide accurate navigation on approach for future missions by measuring the locations of the satellites of Mars relative to background stars. Because Mars will be a bright extended object just outside the camera"s field of view, stray light control at small angles is essential. The ONC optomechanical design was analyzed by stray light experts and appropriate baffles were implemented. However, stray light testing revealed significantly higher levels of light than expected at the most critical angles. The primary error source proved to be the interface between ground glass surfaces (and the paint that had been applied to them) and the polished surfaces of the lenses. This paper will describe troubleshooting and correction of the problem, as well as other lessons learned that affected stray light performance.

Injuries associated with in-line skating from the Canadian hospitals injury reporting and prevention program database.

PubMed

Ellis, J A; Kierulf, J C; Klassen, T P

1995-01-01

In-line skating, also known as rollerblading, is an increasingly popular recreational activity that carries with it the potential for injury. As reported in the Canadian Hospitals Injury Reporting and Prevention Program database (CHIRPP), 194 children were injured while in-line skating. Fractures to the radius and ulna were the most common type of injury sustained (57.5%), followed by lacerations and abrasions (14.9%). Five children had concussions and very few children reported wearing protective gear such as a helmet or wrist, elbow and knee protectors. Compared to the database overall, in-line skaters suffered more severe injuries and were more likely to require follow-up treatment. Safety implications in relation to protective gear and learning the sport of in-line skating are discussed.

Continuous-Flow In-Line Solvent-Swap Crystallization of Vitamin D3

PubMed Central

2017-01-01

A continuous tandem in-line evaporation–crystallization is presented. The process includes an in-line solvent-swap step, suitable to be coupled to a capillary based cooler. As a proof of concept, this setup is tested in a direct in-line acetonitrile mediated crystallization of Vitamin D3. This configuration is suitable to be coupled to a new end-to-end continuous microflow synthesis of Vitamin D3. By this procedure, vitamin particles can be crystallized in continuous flow and isolated using an in-line continuous filtration step. In one run in just 1 min of cooling time, ∼50% (w/w) crystals of Vitamin D3 are directly obtained. Furthermore, the polymorphic form as well as crystals shape and size properties are described in this paper.

Estimation of heat loss from a cylindrical cavity receiver based on simultaneous energy and exergy analyses

NASA Astrophysics Data System (ADS)

Madadi, Vahid; Tavakoli, Touraj; Rahimi, Amir

2015-03-01

This study undertakes the experimental and theoretical investigation of heat losses from a cylindrical cavity receiver employed in a solar parabolic dish collector. Simultaneous energy and exergy equations are used for a thermal performance analysis of the system. The effects of wind speed and its direction on convection loss has also been investigated. The effects of operational parameters, such as heat transfer fluid mass flow rate and wind speed, and structural parameters, such as receiver geometry and inclination, are investigated. The portion of radiative heat loss is less than 10%. An empirical and simplified correlation for estimating the dimensionless convective heat transfer coefficient in terms of the Re mathrm {Re} number and the average receiver wall temperature is proposed. This correlation is applicable for a wind speed range of 0.10.1 to 10 m/s. Moreover, the proposed correlation for Nu mathrm {Nu} number is validated using experimental data obtained through the experiments carried out with a conical receiver with two aperture diameters. The coefficient of determination R2 and the normalized root mean square error (NRMSE) parameters were calculated, and the results show that there is a good agreement between predicted results and experimental data. R2 is greater than 0.950.95 and the NRMSE parameters is less than 0.060.06 in this analysis.

Evaluation of a small diameter baffled culvert for passing juvenile salmonids.

Treesearch

Mason D. Bryant

1981-01-01

A 90-cm-diameter culvert with off-set baffles was set at a 10-percent gradient in an artificial stream channel on Admiralty Island, Alaska. Coho salmon, Dolly Varden char, and cutthroat trout, all less than 120-mm fork length, were able to move up the 9-m culvert. Additional work is needed to determine an upper discharge limit and to evaluate field installations.

Solidification Using the Baffle in Sealed Ampoules

NASA Technical Reports Server (NTRS)

Ostrogorsky, A.; Marin, C.; Churilov, A.; Volz, M. P.; Bonner, W. A.; Spivey, R. A.; Smith, G.

2003-01-01

Solidification Using a Baffle in Sealed Ampoules (SUBSA) is the first investigation conducted in the Microgravity Science Glovebox (MSG) Facility at the International Space Station (ISS) Alpha. In July, August and September of 2002, 8 single crystals of InSb, doped with Te and Zn, were directionally solidified in microgravity. Ground based tests, related numerical modeling and images of the growth process obtained in microgravity are presented.

Low cost anaerobic system for Indonesia: single baffled septic tank.

PubMed

Wibisono, G; Mathew, K; Ho, Goen

2003-01-01

The insertion of a single baffle into a laboratory septic tank to mix incoming feed with sludge has been shown to improve anaerobic degradation of the feed. This is particularly true of soluble organic matter such as glucose. Oil or cellulose fed separately does not undergo degradation. It is expected however that a balanced feed such as sewage will be better degraded.

A study of response time of pitot pressure probes designed for rapid response and protection of transducer

NASA Technical Reports Server (NTRS)

Moore, J. A.

1979-01-01

An eight orifice probe, designed to protect the transducer without the use of a baffle, was compared to a standard orifice-baffle probe in the small shock tube and in the expansion tube under normal run conditions. In both facilities, the response time of eight orifice probe was considerable better than the standard probe design.

Combustion stability with baffles, absorbers and velocity sensitive combustion. [liquid propellant rocket combustors

NASA Technical Reports Server (NTRS)

Mitchell, C. E.

1980-01-01

Analytical and computational techniques were developed to predict the stability behavior of liquid propellant rocket combustors using damping devices such as acoustic liners, slot absorbers, and injector face baffles. Models were developed to determine the frequency and decay rate of combustor oscillations, the spatial and temporal pressure waveforms, and the stability limits in terms of combustion response model parameters.

Solidification Using a Baffle in Sealed Ampoules (SUBSA)

NASA Technical Reports Server (NTRS)

Marin, C.; Ostrogorsky, A. G.; Volz, M.; Luz, P.; Jeter, L.; Spivey, R.; Burton, H.; Smith, G.; Knowles, T. R.; Bonner, W. A.

2003-01-01

Solidification Using a Baffle in Sealed Ampoules (SUBSA) will be the first materials science experiment conducted in the Microgravity Science Glovebox (MSG) Facility at the International Space Station (ISS) Alpha. The launch is schedule for May 31, 2002. Using the specially developed furnace, 10 Te and Zn-doped single crystals of InSb will be directionally solidified in microgravity. A key goal of the SUBSA investigation is to (i) clarify the origin of the melt motion in space laboratories and (ii) to reduce the magnitude of the melt motion to the point that it does not interfere with the transport phenomena. These goals will be accomplished through a special ampoule and furnace design. A disk-shaped baffle, positioned close to the freezing front, is used to reduce melt motion. Furthermore, the solidification will be visualized by using a transparent furnace, with a video camera, continuously sending images to the earth. This allows detection of bubbles and melt de-wetting that could cause surface tension driven convection. In preparation for the space experiments, 30 ground-based experiments were conducted. The results of ground based tests and numerical modeling will be presented. Based on numerical modeling, 12 mm 1D silica ampoules were selected. The small diameter ampoule favors closer placement of the baffle to the interface, without excessive radial segregation caused by forced convection while providing more damping of natural convection. The parts in the silica ampoule include 2 carbon springs made by Energy Science Laboratories, Inc., a pyrocarbon-coated graphite cylinder, pyrocarbon-coated graphite a baffle with the shaft and the InSb charge with the seed crystal grown by W.A. Bonner of Crystallod Inc.

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

Code of Federal Regulations, 2010 CFR

2010-07-01

.../raw mills. 63.1343 Section 63.1343 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... 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 any...

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 Network...

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 Network...

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 Network...

Fiber optic refractive index and magnetic field sensors based on microhole-induced inline Mach-Zehnder interferometers

NASA Astrophysics Data System (ADS)

Chen, Feifei; Jiang, Yi; Zhang, Liuchao; Jiang, Lan; Wang, Sumei

2018-04-01

A compact microhole-induced fiber optic inline Mach-Zehnder interferometer (MZI) is demonstrated for measurements of refractive index (RI) and magnetic field. Inline MZIs with different etched diameters, different interaction lengths and different sizes of microholes are fabricated and assessed. The optical transmission spectra of the inline MZIs immersed into a series of liquids are characterized and analysed. Experimental results show that liquid RI sensitivity as high as 539.8436 nm RIU-1 in the RI range of 1.3352-1.4113 RIU is achieved and also exhibits good linearity with a correlation coefficient  >93%. An inline MZI is also fabricated to be a magnetic field sensor by using magnetic fluid material. The experimental results show that this magnetic field sensor has a high sensitivity of  -275.6 pm Oe-1. The inline MZI-based fiber optic sensors possess many advantages, such as small size, simple fabrication, high sensitivity and good linearity, which has a wide application potential in chemical, biological and environmental sensing fields.

Objective Assessment of Sunburn and Minimal Erythema Doses: Comparison of Noninvasive In Vivo Measuring Techniques after UVB Irradiation

NASA Astrophysics Data System (ADS)

Huang, Min-Wei; Lo, Pei-Yu; Cheng, Kuo-Sheng

2010-12-01

Military personnel movement is exposed to solar radiation and sunburn is a major problem which can cause lost workdays and lead to disciplinary action. This study was designed to identify correlation parameters in evaluating in vivo doses and epidermis changes following sunburn inflammation. Several noninvasive bioengineering techniques have made objective evaluations possible. The volar forearms of healthy volunteers ([InlineEquation not available: see fulltext.]), 2 areas, 20 mm in diameter, were irradiated with UVB 100 mj/[InlineEquation not available: see fulltext.] and 200 mj/[InlineEquation not available: see fulltext.], respectively. The skin changes were recorded by several monitored techniques before and 24 hours after UV exposures. Our results showed that chromameter [InlineEquation not available: see fulltext.] value provides more reliable information and can be adopted with mathematical model in predicting the minimal erythema dose (MED) which showed lower than visual assessment by 10 mj/[InlineEquation not available: see fulltext.] (Pearson correlation coefficient [InlineEquation not available: see fulltext.]). A more objective measure for evaluation of MED was established for photosensitive subjects' prediction and sunburn risks prevention.

Optimizing gas transfer to improve growth rate of Haematococcus pluvialis in a raceway pond with chute and oscillating baffles.

PubMed

Yang, Zongbo; Cheng, Jun; Li, Ke; Zhou, Junhu; Cen, Kefa

2016-08-01

Up-down chute and oscillating (UCO) baffles were used to generate vortex and oscillating flow field to improve growth rate of Haematococcus pluvialis in a raceway pond. Effects of gas flow rate, solution velocity, and solution depth on solution mass transfer coefficient and mixing time were evaluated using online pH and dissolved oxygen probes. Mass transfer coefficient increased by 1.3 times and mixing time decreased by 33% when UCO baffles were used in the H. pluvialis solution, resulting in an 18% increase in biomass yield with 2% CO2. The H. pluvialis biomass yield further increased to 1.5g/L, and astaxanthin composition accumulated to 29.7mg/L under relatively higher light intensity and salinity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Space- and Ground-Based Crystal Growth Using a Baffle (CGB)

NASA Technical Reports Server (NTRS)

Ostrogorsky, A. G.; Marin, C.; Peignier, T.; Duffar, T.; Volz, M.; Jeter, L.; Luz, P.

2001-01-01

The composition of semiconductor crystals produced in space by conventional melt-growth processes (directional solidification and zone melting) is affected by minute levels of residual micro-acceleration, which causes natural convection. The residual acceleration has random magnitude, direction and frequency. Therefore, the velocity field in the melt is apriori unpredictable. As a result, the composition of the crystals grown in space can not be predicted and reproduced. The method for directional solidification with a submerged heater or a baffle was developed under NASA sponsorship. The disk-shaped baffle acts as a partition, creating a small melt zone at the solid-liquid interface. As a result, in ground based experiment the level of buoyancy-driven convection at the interface is significantly reduced. In several experiments with Te-doped GaSb, nearly diffusion controlled segregation was achieved.

Spanwise visualization of the flow around a three-dimensional foil with leading edge protuberances

NASA Astrophysics Data System (ADS)

Stanway, M. J.; Techet, A. H.

2006-11-01

Studies of model humpback whale fins have shown that leading edge protuberances, or tubercles, can lead to delayed stall and increased lift at higher angles of attack, compared to foils with geometrically smooth leading edges. Such enhanced performance characteristics could prove highly useful in underwater vehicles such as gliders or long range AUVs (autonomous underwater vehicles). In this work, Particle Imaging Velocimetry (PIV) is performed on two static wings in a water tunnel over a range of angles of attack. These three- dimensional, finite-aspect ratio wings are modeled after a humpback whale flipper and are identical in shape, tapered from root to tip, except for the leading edge. In one of the foils the leading edge is smooth, whereas in the other, regularly spaced leading edge bumps are machined to simulate the whale’s fin tubercles. Results from these PIV tests reveal distinct cells where coherent flow structures are destroyed as a result of the leading edge perturbations. Tests are performed at Reynolds numbers Re ˜ O(10^5), based on chordlength, in a recirculating water tunnel. An inline six-axis load cell is mounted to measure the forces on the foil over a range of static pitch angles. It is hypothesized that this spanwise breakup of coherent vortical structures is responsible for the delayed angle of stall. These quantitative experiments complement exiting qualitative studies with two dimensional foils.

APPARATUS FOR CLEANING GASES WITH ELECTROSTATICALLY CHARGED PARTICLES

DOEpatents

Johnstone, H.F.

1960-02-01

An apparatus is described for cleaning gases with the help of electrostatically charged pellets. The pellets are blown past baffles in a conduit and into the center of a rotuting body of the gas to be cleaned. The pellets are charged electrostatically by impinging on the baffles. The pellets collect the particles suspended in the gas in their passage from the center of the rotating body to its edge.

Baffles Promote Wider, Thinner Silicon Ribbons

NASA Technical Reports Server (NTRS)

Seidensticker, Raymond G.; Mchugh, James P.; Hundal, Rolv; Sprecace, Richard P.

1989-01-01

Set of baffles just below exit duct of silicon-ribbon-growing furnace reduces thermal stresses in ribbons so wider ribbons grown. Productivity of furnace increased. Diverts plume of hot gas from ribbon and allows cooler gas from top of furnace to flow around. Also shields ribbon from thermal radiation from hot growth assembly. Ribbon cooled to lower temperature before reaching cooler exit duct, avoiding abrupt drop in temperature as entering duct.

Entropy analysis of frequency and shape change in horseshoe bat biosonar

NASA Astrophysics Data System (ADS)

Gupta, Anupam K.; Webster, Dane; Müller, Rolf

2018-06-01

Echolocating bats use ultrasonic pulses to collect information about their environments. Some of this information is encoded at the baffle structures—noseleaves (emission) and pinnae (reception)—that act as interfaces between the bats' biosonar systems and the external world. The baffle beam patterns encode the direction-dependent sensory information as a function of frequency and hence represent a view of the environment. To generate diverse views of the environment, the bats can vary beam patterns by changes to (1) the wavelengths of the pulses or (2) the baffle geometries. Here we compare the variability in sensory information encoded by just the use of frequency or baffle shape dynamics in horseshoe bats. For this, we use digital and physical prototypes of both noseleaf and pinnae. The beam patterns for all prototypes were either measured or numerically predicted. Entropy was used as a measure to compare variability as a measure of sensory information encoding capacity. It was found that new information was acquired as a result of shape dynamics. Furthermore, the overall variability available for information encoding was similar in the case of frequency or shape dynamics. Thus, shape dynamics allows the horseshoe bats to generate diverse views of the environment in the absence of broadband biosonar signals.

Effects of rearing density and raceway conformation on growth, food conversion, and survival of juvenile spring chinook salmon

USGS Publications Warehouse

Ewing, R.D.; Sheahan, J.E.; Lewis, M.A.; Palmisano, Aldo N.

2000-01-01

Four brood years of juvenile spring chinook salmon Oncorhynchus tshawytscha were reared in conventional and baffled raceways at various rearing densities and loads at Willamette Hatchery, Oregon. A period of rapid linear growth occurred from August to November, but there was little or no growth from November to March when the fish were released. Both fall and winter growth rates were inversely related to rearing density. Final weight and length were also inversely related to rearing density. No significant relationship between load and any growth variable was observed. Fish reared at lower densities in conventional raceways tended to develop bimodal length distributions in winter and early spring. Fish reared in conventional raceways showed significantly larger growth rates and final lengths and weights than those reared in baffled raceways. Food conversions and average delivery times for feed were significantly greater in baffled than in conventional raceways. No significant relationships were observed between either rearing density or load and condition factor, food conversion, or mortality. Mortality was not significantly different between the two raceway types. When fish were transported to seawater for further rearing, there were no significant relationships between mortality in seawater and rearing density or load, but fish reared in baffled raceways had significantly higher mortality than those reared in conventional raceways.

Evaluation of power density on the bioethanol production using mesoscale oscillatory baffled reactor and stirred tank reactor

NASA Astrophysics Data System (ADS)

Yussof, H. W.; Bahri, S. S.; Mazlan, N. A.

2018-03-01

A recent development in oscillatory baffled reactor technology is down-scaling the reactor, so that it can be used for production of small-scale bioproduct. In the present study, a mesoscale oscillatory baffled reactor (MOBR) with central baffle system was developed. The reactor performance of the MOBR was compared with conventional stirred tank reactor (STR) to evaluate the performance of bioethanol fermentation using Saccharomyces cerevisiae. Evaluation was made at similar power density of 24.21, 57.38, 112.35 and 193.67 Wm-3 by varying frequency (f), amplitude (xo) and agitation speed (rpm). It was found that the MOBR improved the mixing intensity resulted in lower glucose concentration (0.988 gL-1) and higher bioethanol concentration (38.98 gL-1) after 12 hours fermentation at power density of 193.67 Wm-3. Based on the results, the bioethanol yield obtained using MOBR was 39% higher than the maximum achieved in STR. Bioethanol production using MOBR proved to be feasible as it is not only able to compete with conventional STR but also offers advantages of straight-forward scale-up, whereas it is complicated and difficult in STR. Overall, MOBR offers great prospective over the conventional STR.

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 of...

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 of...

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... 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 of...

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 of...

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 of...

Characteristics and measurement of supersonic projectile shock waves by a 32-microphone ring array

NASA Astrophysics Data System (ADS)

Chang, Ho; Wu, Yan-Chyuan; Tsung, Tsing-Tshih

2011-08-01

This paper discusses about the characteristics of supersonic projectile shock wave in muzzle region during firing of high explosive anti-tank (HEAT) and high explosive (HE) projectiles. HEAT projectiles are fired horizontally at a muzzle velocity of Mach 3.5 from a medium caliber tank gun equipped with a newly designed multi-perforated muzzle brake, whereas HE projectiles are fired at elevation angles at a muzzle velocity of Mach 2 from a large caliber howitzer equipped with a newly designed double-baffle muzzle brake. In the near field, pressure signatures of the N-wave generated from projectiles are measured by 32-microphone ring array wrapped by cotton sheath. Records measured by the microphone array are used to demonstrate several key characteristics of the shock wave of supersonic projectile. All measurements made in this study can be a significant reference for developing guns, tanks, or the chassis of fighting vehicles.

Rutherford's Nuclear Model

NASA Astrophysics Data System (ADS)

Heibron, John

2011-04-01

Rutherford's nuclear model originally was a theory of scattering that represented both the incoming alpha particles and their targets as point charges. The assumption that the apha particle, which Rutherford knew to be a doubly ionized helium atom, was a bare nucleus, and the associated assumption that the electronic structure of the atom played no significant role in large-angle scattering, had immediate and profound consequences well beyond the special problem for which Rutherford introduced them. The group around him in Manchester in 1911/12, which included Niels Bohr, Charles Darwin, Georg von Hevesy, and Henry Moseley, worked out some of these consequences. Their elucidation of radioactivity, isotopy, atomic number, and quantization marked an epoch in microphysics. Rutherford's nuclear model was exemplary not only for its fertility and picturability, but also for its radical simplicity. The lecturer will not undertake to answer the baffling question why such simple models work.

Method for pulse control in a laser including a stimulated brillouin scattering mirror system

DOEpatents

Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

2007-10-23

A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.

Stimulated Brillouin scattering mirror system, high power laser and laser peening method and system using same

DOEpatents

Dane, C Brent [Livermore, CA; Hackel, Lloyd [Livermore, CA; Harris, Fritz B [Rocklin, CA

2007-04-24

A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.

Characteristics and measurement of supersonic projectile shock waves by a 32-microphone ring array.

PubMed

Chang, Ho; Wu, Yan-Chyuan; Tsung, Tsing-Tshih

2011-08-01

This paper discusses about the characteristics of supersonic projectile shock wave in muzzle region during firing of high explosive anti-tank (HEAT) and high explosive (HE) projectiles. HEAT projectiles are fired horizontally at a muzzle velocity of Mach 3.5 from a medium caliber tank gun equipped with a newly designed multi-perforated muzzle brake, whereas HE projectiles are fired at elevation angles at a muzzle velocity of Mach 2 from a large caliber howitzer equipped with a newly designed double-baffle muzzle brake. In the near field, pressure signatures of the N-wave generated from projectiles are measured by 32-microphone ring array wrapped by cotton sheath. Records measured by the microphone array are used to demonstrate several key characteristics of the shock wave of supersonic projectile. All measurements made in this study can be a significant reference for developing guns, tanks, or the chassis of fighting vehicles.

Sealed Battery Block Provided With A Cooling System

DOEpatents

Verhoog, Roelof; Barbotin, Jean-Loup

1999-11-16

The present invention relates to a sealed battery block operating at a pressure of at least 1 bar relative, the battery including a container made of a plastics material and made up of a lid and of a case subdivided into wells by at least one partition, said battery being provided with a cooling system including two cheek plates made of a plastics material and co-operating with the outside faces of respective ones of two opposite walls of said case, each cheek plate co-operating with the corresponding wall to define a compartment provided with a plurality of ribs forming baffles for fluid flow purposes, and with an inlet orifice and an outlet orifice for the fluid, said battery being characterized in that each of said ribs extends in a direction that forms an angle relative to the plane of said partition lying in the range 60.degree. to 90.degree..

Hydrodynamic optimization of membrane bioreactor by horizontal geometry modification using computational fluid dynamics.

PubMed

Yan, Xiaoxu; Wu, Qing; Sun, Jianyu; Liang, Peng; Zhang, Xiaoyuan; Xiao, Kang; Huang, Xia

2016-01-01

Geometry property would affect the hydrodynamics of membrane bioreactor (MBR), which was directly related to membrane fouling rate. The simulation of a bench-scale MBR by computational fluid dynamics (CFD) showed that the shear stress on membrane surface could be elevated by 74% if the membrane was sandwiched between two baffles (baffled MBR), compared with that without baffles (unbaffled MBR). The effects of horizontal geometry characteristics of a bench-scale membrane tank were discussed (riser length index Lr, downcomer length index Ld, tank width index Wt). Simulation results indicated that the average cross flow of the riser was negatively correlated to the ratio of riser and downcomer cross-sectional area. A relatively small tank width would also be preferable in promoting shear stress on membrane surface. The optimized MBR had a shear elevation of 21.3-91.4% compared with unbaffled MBR under same aeration intensity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Validation of Slosh Model Parameters and Anti-Slosh Baffle Designs of Propellant Tanks by Using Lateral Slosh Testing

NASA Technical Reports Server (NTRS)

Perez, Jose G.; Parks, Russel, A.; Lazor, Daniel R.

2012-01-01

The slosh dynamics of propellant tanks can be represented by an equivalent mass-pendulum-dashpot mechanical model. The parameters of this equivalent model, identified as slosh mechanical model parameters, are slosh frequency, slosh mass, and pendulum hinge point location. They can be obtained by both analysis and testing for discrete fill levels. Anti-slosh baffles are usually needed in propellant tanks to control the movement of the fluid inside the tank. Lateral slosh testing, involving both random excitation testing and free-decay testing, are performed to validate the slosh mechanical model parameters and the damping added to the fluid by the anti-slosh baffles. Traditional modal analysis procedures were used to extract the parameters from the experimental data. Test setup of sub-scale tanks will be described. A comparison between experimental results and analysis will be presented.

Validation of Slosh Model Parameters and Anti-Slosh Baffle Designs of Propellant Tanks by Using Lateral Slosh Testing

NASA Technical Reports Server (NTRS)

Perez, Jose G.; Parks, Russel A.; Lazor, Daniel R.

2012-01-01

The slosh dynamics of propellant tanks can be represented by an equivalent pendulum-mass mechanical model. The parameters of this equivalent model, identified as slosh model parameters, are slosh mass, slosh mass center of gravity, slosh frequency, and smooth-wall damping. They can be obtained by both analysis and testing for discrete fill heights. Anti-slosh baffles are usually needed in propellant tanks to control the movement of the fluid inside the tank. Lateral slosh testing, involving both random testing and free-decay testing, are performed to validate the slosh model parameters and the damping added to the fluid by the anti-slosh baffles. Traditional modal analysis procedures are used to extract the parameters from the experimental data. Test setup of sub-scale test articles of cylindrical and spherical shapes will be described. A comparison between experimental results and analysis will be presented.

Monolithic fuel injector and related manufacturing method

DOEpatents

Ziminsky, Willy Steve [Greenville, SC; Johnson, Thomas Edward [Greenville, SC; Lacy, Benjamin [Greenville, SC; York, William David [Greenville, SC; Stevenson, Christian Xavier [Greenville, SC

2012-05-22

A monolithic fuel injection head for a fuel nozzle includes a substantially hollow vesicle body formed with an upstream end face, a downstream end face and a peripheral wall extending therebetween, an internal baffle plate extending radially outwardly from a downstream end of the bore, terminating short of the peripheral wall, thereby defining upstream and downstream fuel plenums in the vesicle body, in fluid communication by way of a radial gap between the baffle plate and the peripheral wall. A plurality of integral pre-mix tubes extend axially through the upstream and downstream fuel plenums in the vesicle body and through the baffle plate, with at least one fuel injection hole extending between each of the pre-mix tubes and the upstream fuel plenum, thereby enabling fuel in the upstream plenum to be injected into the plurality of pre-mix tubes. The fuel injection head is formed by direct metal laser sintering.

Dynamic characteristics of a 30-centimeter mercury ion thruster

NASA Technical Reports Server (NTRS)

Serafini, J. S.; Mantenieks, M. A.; Rawlin, V. K.

1975-01-01

The present work reports on measurements of the fluctuations in the beam current, discharge current, neutralizer keeper current, and discharge voltage of a 30-cm ion thruster made with 60Hz laboratory-type power supplies. The intensities of the fluctuations (ratio of the root-mean-square magnitude to time-average quantity) were found to depend significantly on the beam and magnetic baffle currents. The shape of the frequency spectra of the discharge plasma fluctuations was related to the beam and magnetic baffle currents. The predominant peaks of the beam and discharge current spectra occurred at frequencies less than 30 kilohertz. This discharge chamber resonance could be attributable to ion-acoustic wave phenomena. Cross-correlations of the discharge and beam currents indicated that the dependence on the magnetic baffle current was strong. The measurements revealed that the discharge current fluctuations directly contribute to the beam current fluctuations and that the power supply characteristics can modify these fluctuations.

Thermal Analysis of the Advanced Technology Large Aperture Space Telescope (ATLAST) 8 Meter Primary Mirror

NASA Technical Reports Server (NTRS)

Hornsby, Linda; Stahl, H. Philip; Hopkins, Randall C.

2010-01-01

The Advanced Technology Large Aperture Space Telescope (ATLAST) preliminary design concept consists of an 8 meter diameter monolithic primary mirror enclosed in an insulated, optical tube with stray light baffles and a sunshade. ATLAST will be placed in orbit about the Sun-Earth L2 and will experience constant exposure to the sun. The insulation on the optical tube and sunshade serve to cold bias the telescope which helps to minimize thermal gradients. The primary mirror will be maintained at 280K with an active thermal control system. The geometric model of the primary mirror, optical tube, sun baffles, and sunshade was developed using Thermal Desktop(R) SINDA/FLUINT(R) was used for the thermal analysis and the radiation environment was analyzed using RADCAD(R). A XX node model was executed in order to characterize the static performance and thermal stability of the mirror during maneuvers. This is important because long exposure observations, such as extra-solar terrestrial planet finding and characterization, require a very stable observatory wave front. Steady state thermal analyses served to predict mirror temperatures for several different sun angles. Transient analyses were performed in order to predict thermal time constant of the primary mirror for a 20 degree slew or 30 degree roll maneuver. This paper describes the thermal model and provides details of the geometry, thermo-optical properties, and the environment which influences the thermal performance. All assumptions that were used in the analysis are also documented. Parametric analyses are summarized for design parameters including primary mirror coatings and sunshade configuration. Estimates of mirror heater power requirements are reported. The thermal model demonstrates results for the primary mirror heated from the back side and edges using a heater system with multiple independently controlled zones.

40 CFR 63.1344 - Operating limits for kilns and in-line kiln/raw mills.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 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 kiln/raw... specified in paragraph (b) of this section. The owner or operator of an in-line kiln/raw mill subject to a D...

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

... other than kilns; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers; and raw and finish mills, and open clinker piles. 63.1345 Section 63.1345 Protection of Environment... for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and reconstructed...

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 product...

Dental injuries in inline skating - level of information and prevention.

PubMed

Fasciglione, Daniele; Persic, Robert; Pohl, Yango; Filippi, Andreas

2007-06-01

Inline skating belongs like ice hockey, rugby, and boxing to sporting activities with high-risk of suffering tooth accidents. Because of high velocity and loss of balance, especially on uneven ground, the injury potential in inline skating is higher. The objective of this work was to conduct a comparative study between Switzerland and Germany. The questions focussed on the frequency of tooth accidents, their prevention by mouthguard and the level of information about emergency measures after dental trauma and the resulting consequences for athletes. Using a standardized questionnaire totally 612 individuals, 324 men and 288 women, in two countries belonging to three different divisions (fun, fitness and speed) were surveyed. Fifty-six (9.2%) of these 612 interviewees have already experienced a tooth injury while inline skating. More than half of all interviewed players (68.3%) were aware of the possibility of replanting avulsed teeth. Only 32.4% were familiar with the tooth rescue kit. Just 65.4% knew mouthguard and only 1.9% of those athletes (n = 12) wore a mouthguard while inline skating. The results show that the area of inline skating requires more information about preventing dental trauma through sports associations and dentists.

Nitrite Interference with Soluble COD Measurements from Aerobically Treated Wastewater.

PubMed

Ferraz, Fernanda M; Yuan, Qiuyan

2017-06-01

  This study aimed to determine the interference of nitrite () with soluble chemical oxygen demand (COD) measurements from the effluent of landfill leachate treated by sequencing batch reactors (SBRs). Synthetic wastewater assimilating young and old landfill leachate was used as influent for SBR1 and SBR2, respectively. A mixture of raw wastewater and landfill leachate was used as influent for SBR3. Due to the high ammonia concentration in the influent, different levels of partial nitrification were observed in all the reactors and was detected in the effluents. Theoretically, when is present in the effluent, 1 mg/L of accounts for 1.1 mg/L of COD (i.e., 1.1 mg COD/mg ) due to the oxidation of to . It was found that the value of 1.1 mg COD/mg was 3 times higher than the values obtained in the experiments with SBR1 and SBR3. In addition, the values obtained in the experiments with SBR2 were much higher than 1.1 mg COD/mg . These results suggest that the theoretical value of 1.1 mg COD/mg cannot be applied to predict the COD values caused by nitrite in the tested wastewaters. To obtain an accurate measurement of soluble COD in samples that contain nitrite, nitrite should be eliminated before the measurements.

Skateboarding: more dangerous than roller skating or in-line skating.

PubMed

Osberg, J S; Schneps, S E; Di Scala, C; Li, G

1998-10-01

To describe the circumstances, severity, and outcomes of skating-related injuries among children admitted to trauma centers. A cross-sectional comparison of roller skaters (n = 154), in-line skaters (n = 190), and skateboarders (n = 254) aged 5 to 19 years who were hospitalized with injuries. Seventy-nine hospitals and pediatric trauma centers participating in the National Pediatric Trauma Registry between October 1988 and April 1997. Three quarters (75.8%) of the study sample were male, nearly half (47.8%) were injured on roads, and more than one third (37.1%) had head injuries. Among skateboarders, 50.8% had head injuries compared with 33.7% of in-line skaters and 18.8% of roller skaters (P<.001). According to the Injury Severity Score, injuries to skateboarders were 8 times more likely to be severe or critical compared with roller skaters' injuries and more than 2 times as likely to be severe or critical compared with in-line skaters' injuries. Mean hospital length of stay was 6.0 days for skateboarders, 3.4 days for in-line skaters, and 2.4 days for roller skaters (P<.001). Skateboarders were more likely to be male and to be injured on roads than were in-line skaters or roller skaters. Skateboarding-related injuries are more severe and have more serious consequences than roller skating or in-line skating injuries. Research is needed to identify ergonomic and behavioral factors responsible for higher head injury risk to skateboarders, and interventions are needed to reduce the risk.

Video analysis of falls experienced by paediatric iceskaters and roller/inline skaters

PubMed Central

Knox, C L; Comstock, R D

2006-01-01

Objectives To evaluate differences in the way iceskaters and roller/inline skaters fall. Methods Children's falls related to skating were videotaped and categorised based on type of skating activity, child's estimated age, direction of fall, whether the child attempted to break the fall, and whether the head struck the skating surface. Results In total, 216 iceskating and 201 roller/inline skating falls were captured on videotape. In both iceskating and roller/inline skating, the majority of falls were forward in direction. The skaters attempted to break the falls with their arms or hands in over 90% of falls in both iceskating (93.1%) and roller/inline skating (94.5%). A greater proportion of falls in iceskating resulted in the head striking the skating surface (13.0%) than did those in roller/inline skating (3.0%) (odds ratio = 4.8; 95% confidence interval 1.9 to 13.3; p<0.001). Conclusions This study found that paediatric iceskaters and roller/inline skaters fall similarly and that both types of skaters try to break their falls with their arms or hands; however, because iceskating takes place on a low friction surface, attempts to break falls with the arms or hands are often unsuccessful, leading to head and face injuries. The development of a new type of protective gear, a wrist guard with a non‐slip palm, should stop iceskaters from striking the head, protect against upper extremity fractures, and unlike a bulky helmet, should not discourage children from skating. PMID:16505087

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.

75 FR 62331 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-14, DC-9-15, and DC-9-15F...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-08

... switch and new in-line fuses for the pressure switch, as applicable; and change the wiring; on the left...). SUMMARY: We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD would require installing new in-line fuses for the fuel level float switch and new in-line...

EUV-angle resolved scatter (EUV-ARS): a new tool for the characterization of nanometre structures

NASA Astrophysics Data System (ADS)

Fernández Herrero, Analía.; Mentzel, Heiko; Soltwisch, Victor; Jaroslawzew, Sina; Laubis, Christian; Scholze, Frank

2018-03-01

The advance of the semiconductor industry requires new metrology methods, which can deal with smaller and more complex nanostructures. Particularly for inline metrology a rapid, sensitive and non destructive method is needed. Small angle X-ray scattering under grazing incidence has already been investigated for this application and delivers significant statistical information which tracks the profile parameters as well as their variations, i.e. roughness. However, it suffers from the elongated footprint at the sample. The advantage of EUV radiation, with its longer wavelengths, is that larger incidence angles can be used, resulting in a significant reduction of the beam footprint. Targets with field sizes of 100 μm and smaller are accessible with our experimental set-up. We present a new experimental tool for the measurement of small structures based on the capabilities of soft X-ray and EUV scatterometry at the PTB soft X-ray beamline at the electron storage ring BESSY II. PTB's soft X-ray radiometry beamline uses a plane grating monochromator, which covers the spectral range from 0.7 nm to 25 nm and was especially designed to provide highly collimated radiation. An area detector covers the scattered radiation from a grazing exit angle up to an angle of 30° above the sample horizon and the fluorescence emission can be detected with an energy dispersive X-ray silicon drift detector. In addition, the sample can be rotated and linearly moved in vacuum. This new set-up will be used to explore the capabilities of EUV-scatterometry for the characterization of nanometre-sized structures.

Radial midframe baffle for can-annular combustor arrangement having tangentially oriented combustor cans

DOEpatents

Rodriguez, Jose L.

2015-09-15

A can-annular gas turbine engine combustion arrangement (10), including: a combustor can (12) comprising a combustor inlet (38) and a combustor outlet circumferentially and axially offset from the combustor inlet; an outer casing (24) defining a plenum (22) in which the combustor can is disposed; and baffles (70) configured to divide the plenum into radial sectors (72) and configured to inhibit circumferential motion of compressed air (16) within the plenum.

Numerical investigation of flow and heat transfer in a novel configuration multi-tubular fixed bed reactor for propylene to acrolein process

NASA Astrophysics Data System (ADS)

Jiang, Bin; Hao, Li; Zhang, Luhong; Sun, Yongli; Xiao, Xiaoming

2015-01-01

In the present contribution, a numerical study of fluid flow and heat transfer performance in a pilot-scale multi-tubular fixed bed reactor for propylene to acrolein oxidation reaction is presented using computational fluid dynamics (CFD) method. Firstly, a two-dimensional CFD model is developed to simulate flow behaviors, catalytic oxidation reaction, heat and mass transfer adopting porous medium model on tube side to achieve the temperature distribution and investigate the effect of operation parameters on hot spot temperature. Secondly, based on the conclusions of tube-side, a novel configuration multi-tubular fixed-bed reactor comprising 790 tubes design with disk-and-doughnut baffles is proposed by comparing with segmental baffles reactor and their performance of fluid flow and heat transfer is analyzed to ensure the uniformity condition using molten salt as heat carrier medium on shell-side by three-dimensional CFD method. The results reveal that comprehensive performance of the reactor with disk-and-doughnut baffles is better than that of with segmental baffles. Finally, the effects of operating conditions to control the hot spots are investigated. The results show that the flow velocity range about 0.65 m/s is applicable and the co-current cooling system flow direction is better than counter-current flow to control the hottest temperature.

Synergetic Effects of Runaway and Disruption Induced by VDE on the First Wall Damage in HL-2A

NASA Astrophysics Data System (ADS)

Song, Xianying; Yang, Jinwei; Li, Xu; Yuan, Guoliang; Zhang, Yipo

2012-03-01

The plasma facing component in HL-2A has been damaged seriously after disruption, and for this reason its operation is suspended for maintenance. The experimental phenomena and plasma configurations, calculated by the current filament code (CF-code) using the plasma parameters measured by diagnostics and the signals of the magnetic probes, confirm that the first wall is damaged by the synergetic effects of runaway electrons and disruption induced by a vertical displacement event (VDE). When the plasma column is displaced upward/downward, the strong runaway electrons normally hit the baffle plate of the MP3 or MP1 coil in the upper and lower divertor during the disruption, causing the baffle plates to be holed and wrinkled by the energetic runaway current, and water (for cooling or heating the baffle plates) to leak into the vacuum vessel. Another disastrous consequence is that bellows underlying the baffle plate and outside the coil of MP3 for connecting two segments of the jacket casing pipe are punctured by arcing. The arc may be part of the halo current that forms a complete circuit. The experimental phenomena are indirect but compelling evidence for the existence of a halo current during the disruption and VDE, though the halo current has not been measured by the diagnostics in the HL-2A tokamak.

Wave impact on a deck or baffle

NASA Astrophysics Data System (ADS)

Md Noar, Nor Aida Zuraimi; Greenhow, Martin

2015-02-01

Some coastal or ocean structures have deck-like baffles or horizontal platforms that can be exposed to wave action in heavy seas. A similar situation may occur in partially-filled tanks with horizontal baffles that become engulfed by sloshing waves. This can result in dangerous wave impact loads (slamming) causing a rapid rise of pressures which may lead to local damaging by crack initiation and/or propagation. We consider the wave impact against the whole of underside of horizontal deck (or baffle) projecting from a seawall (or vertical tank wall), previously studied by Wood and Peregrine (1996) using a different method based on conformal mappings. The approach used is to simplify the highly time-dependent and very nonlinear problem by considering the time integral of the pressure over the duration of the impact pressure-impulse, P (x, y). Our method expresses this in terms of eigenfunctions that satisfy the boundary conditions apart from that on the impact region and the matching of the two regions (under the platform and under the free surface); this results in a matrix equation to be solved numerically. As in Wood and Peregrine, we found that the pressure impulse on the deck increases when the length of deck increases, there is a strong pressure gradient beneath the deck near the seaward edge and the maximum pressure impulse occurs at the landward end of the impact zone.

Researchers Demonstrate Liquid Transfer Equipment for Apollo 14 Test

NASA Image and Video Library

1970-12-21

Two researchers at the National Aeronautics and Space Administration (NASA) Lewis Research Center demonstrate the test equipment they devised to study the transfer of liquid in microgravity onboard the Apollo 14 mission. The test was an early step in developing the ability to transfer liquids from a tanker vehicle to spacecraft in space. Researchers needed to know the tank’s outflow characteristics, the fluid’s behavior when entering new tank, and the effects of accelerations. Others had performed some calculations and analytical studies, but no one had examined the complete transfer from one tank to another in microgravity. The early calculations concluded that the transfer process was impossible without devices to control the liquid and gas. This investigation specifically sought to demonstrate the effectiveness of two different surface-tension baffle designs. The experiment was an entirely closed system with two baffled-tanks. The researchers also built a similar device without the baffles. The experiment was carried onboard the Apollo 14 spacecraft and conducted during the coast period on the way to the moon. The two surface tension baffle designs in the separate tanks were shown to be effective both as supply tanks and as receiver tanks. The liquid transferred within two percent of the design value with ingesting gas. The unbaffled tanks ingested gas after only 12-percent of the fluid had transferred.

Lattice dynamics in elemental modulated Sb 2 Te 3 films: Lattice dynamics in elemental modulated Sb 2 Te 3 films

DOE PAGES

Bessas, D.; Winkler, M.; Sergueev, I.; ...

2015-09-03

We investigate the crystallinity and the lattice dynamics in elemental modulated Sbinline imageTeinline image films microscopically using high energy synchrotron radiation diffraction combined with inline imageSb nuclear inelastic scattering. The correlation length is found to be finite but less than 100 . Moreover, the element specific density of phonon states is extracted. A comparison with the element specific density of phonon states in bulk Sbinline imageTeinline image confirms that the main features in the density of phonon states arise from the layered structure. The average speed of sound at inline image inline image, is almost the same compared to bulkmore » Sbinline imageTeinline image at inline image, inline image. Similarly, the change in the acoustic cut-off energy is within the experimental detection limit. Therefore, we suggest that the lattice thermal conductivity in elemental modulated Sbinline imageTeinline image films should not be significantly changed from its bulk value.« less

Scatterometry—fast and robust measurements of nano-textured surfaces

NASA Astrophysics Data System (ADS)

Hannibal Madsen, Morten; Hansen, Poul-Erik

2016-06-01

Scatterometry is a fast, precise and low cost way to determine the mean pitch and dimensional parameters of periodic structures with lateral resolution of a few nanometer. It is robust enough for in-line process control and precise and accurate enough for metrology measurements. Furthermore, scatterometry is a non-destructive technique capable of measuring buried structures, for example a grating covered by a thick oxide layer. As scatterometry is a non-imaging technique, mathematical modeling is needed to retrieve structural parameters that describe a surface. In this review, the three main steps of scatterometry are discussed: the data acquisition, the simulation of diffraction efficiencies and the comparison of data and simulations. First, the intensity of the diffracted light is measured with a scatterometer as a function of incoming angle, diffraction angle and/or wavelength. We discuss the evolution of the scatterometers from the earliest angular scatterometers to the new imaging scatterometers. The basic principle of measuring diffraction efficiencies in scatterometry has remained the same since the beginning, but the instrumental improvements have made scatterometry a state-of-the-art solution for fast and accurate measurements of nano-textured surfaces. The improvements include extending the wavelength range from the visible to the extreme ultra-violet range, development of Fourier optics to measure all diffraction orders simultaneously, and an imaging scatterometer to measure area of interests smaller than the spot size. Secondly, computer simulations of the diffraction efficiencies are discussed with emphasis on the rigorous coupled-wave analysis (RCWA) method. RCWA has, since the mid-1990s, been the preferred method for grating simulations due to the speed of the algorithms. In the beginning the RCWA method suffered from a very slow convergence rate, and we discuss the historical improvements to overcome this challenge, e.g. by the introduction of Li’s factorization rules and the introduction of the normal vector method. The third step is the comparison, where the simulated diffraction efficiencies are compared to the experimental data using an inverse modeling approach. We discuss both a direct optimization scheme using a differential evolution algorithm and a library search strategy where diffraction efficiences of expected structures are collected in a database. For metrology measurements two methods are described for estimating the uncertainty of the fitting parameters. The first method is based on estimating the confidence limits using constant chi square boundaries, which can easily be computed when using the library search strategy. The other method is based on calculating the covariances of all the free parameters using a least square optimization. Scatterometry is already utilized in the semiconductor industry for in-line characterization. However, it also has a large potential for other industrial sectors, including sectors making use of injection molding or roll-2-roll fabrication. Using the library search strategy, the comparison can be performed in ms, making in-line characterization possible and we demonstrate that scatterometry can be used for quality control of injection molded nano-textured plastic samples. With the emerging methods of highly parallel manufacturing of nano-textured devices, scatterometry has great potential to deliver a characterization method for in-line quality control and metrology measurements, which is not possible with conventional characterization techniques. However, there are some open challenges for the scatterometry techniques. These include corrections for measuring on non-ideal samples with a large surface roughness or line-edge roughness and the path towards performing traceable scatterometry measurements.

Direct Imaging of Charge Density Modulation in Switchable Two-Dimensional Electron Gas at the Oxide Hetero-Interfaces by Using Electron Bean Inline Holography

DTIC Science & Technology

2015-08-16

Switchable Two-Dimensional Electron Gas at the Oxide Hetero-Interfaces by Using Electron Bean Inline Holography 5a. CONTRACT NUMBER FA2386-13-1-4136...Hetero-Interfaces by Using Electron Bean Inline Holography 5a. CONTRACT NUMBER FA2386-13-1-4136 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 61102F

Secure Hashing of Dynamic Hand Signatures Using Wavelet-Fourier Compression with BioPhasor Mixing and [InlineEquation not available: see fulltext.] Discretization

NASA Astrophysics Data System (ADS)

Wai Kuan, Yip; Teoh, Andrew B. J.; Ngo, David C. L.

2006-12-01

We introduce a novel method for secure computation of biometric hash on dynamic hand signatures using BioPhasor mixing and[InlineEquation not available: see fulltext.] discretization. The use of BioPhasor as the mixing process provides a one-way transformation that precludes exact recovery of the biometric vector from compromised hashes and stolen tokens. In addition, our user-specific[InlineEquation not available: see fulltext.] discretization acts both as an error correction step as well as a real-to-binary space converter. We also propose a new method of extracting compressed representation of dynamic hand signatures using discrete wavelet transform (DWT) and discrete fourier transform (DFT). Without the conventional use of dynamic time warping, the proposed method avoids storage of user's hand signature template. This is an important consideration for protecting the privacy of the biometric owner. Our results show that the proposed method could produce stable and distinguishable bit strings with equal error rates (EERs) of[InlineEquation not available: see fulltext.] and[InlineEquation not available: see fulltext.] for random and skilled forgeries for stolen token (worst case) scenario, and[InlineEquation not available: see fulltext.] for both forgeries in the genuine token (optimal) scenario.

A tool for selective inline quantification of co-eluting proteins in chromatography using spectral analysis and partial least squares regression.

PubMed

Brestrich, Nina; Briskot, Till; Osberghaus, Anna; Hubbuch, Jürgen

2014-07-01

Selective quantification of co-eluting proteins in chromatography is usually performed by offline analytics. This is time-consuming and can lead to late detection of irregularities in chromatography processes. To overcome this analytical bottleneck, a methodology for selective protein quantification in multicomponent mixtures by means of spectral data and partial least squares regression was presented in two previous studies. In this paper, a powerful integration of software and chromatography hardware will be introduced that enables the applicability of this methodology for a selective inline quantification of co-eluting proteins in chromatography. A specific setup consisting of a conventional liquid chromatography system, a diode array detector, and a software interface to Matlab® was developed. The established tool for selective inline quantification was successfully applied for a peak deconvolution of a co-eluting ternary protein mixture consisting of lysozyme, ribonuclease A, and cytochrome c on SP Sepharose FF. Compared to common offline analytics based on collected fractions, no loss of information regarding the retention volumes and peak flanks was observed. A comparison between the mass balances of both analytical methods showed, that the inline quantification tool can be applied for a rapid determination of pool yields. Finally, the achieved inline peak deconvolution was successfully applied to make product purity-based real-time pooling decisions. This makes the established tool for selective inline quantification a valuable approach for inline monitoring and control of chromatographic purification steps and just in time reaction on process irregularities. © 2014 Wiley Periodicals, Inc.

Magnetic nanoparticles and high-speed countercurrent chromatography coupled in-line and using the same solvent system for separation of quercetin-3-O-rutinoside, luteoloside and astragalin from a Mikania micrantha extract.

PubMed

Wang, Juanqiang; Geng, Shan; Wang, Binghai; Shao, Qian; Fang, Yingtong; Wei, Yun

2017-07-28

A new in-line method of magnetic nanoparticles (MNPs) coupled with high-speed countercurrent chromatography (HSCCC) using a same solvent system during the whole separation process was established to achieve the rapid separation of flavonoids from Mikania micrantha. The adsorption and desorption capacities of five different MNPs for flavonoid standards and Mikania micrantha crude extract were compared and the most suitable magnetic nanoparticle Fe 3 O 4 @SiO 2 @DIH@EMIMLpro was selected as the in-line MNP column. An in-line separation system was established by combining this MNP column with HSCCC through a six-way valve. The comparison between two solvent systems n-hexane-ethyl acetate-methanol-water (3:5:3:5, v/v) and ethyl acetate-methanol-water (25:1:25, v/v) showed that the latter solvent system was more suitable for simultaneously in-line separating three flavonoids quercetin-3-O-rutinoside, luteoloside and astragalin from Mikania micrantha. The purities of these three compounds with the ethyl acetate-methanol-water solvent system were 95.13%, 98.54% and 98.19% respectively. Results showed the established in-line separation system of MNP-HSCCC was efficient, recyclable and served to isolate potential flavonoids with similar polarities from natural complex mixtures. The in-line combination of magnetic nanoparticles with high-speed countercurrent chromatography eluting with the same solvent system during the whole separation process was established for the first time. Copyright © 2017 Elsevier B.V. All rights reserved.

High-Performance Water-Iodinating Cartridge

NASA Technical Reports Server (NTRS)

Sauer, Richard; Gibbons, Randall E.; Flanagan, David T.

1993-01-01

High-performance cartridge contains bed of crystalline iodine iodinates water to near saturation in single pass. Cartridge includes stainless-steel housing equipped with inlet and outlet for water. Bed of iodine crystals divided into layers by polytetrafluoroethylene baffles. Holes made in baffles and positioned to maximize length of flow path through layers of iodine crystals. Resulting concentration of iodine biocidal; suppresses growth of microbes in stored water or disinfects contaminated equipment. Cartridge resists corrosion and can be stored wet. Reused several times before necessary to refill with fresh iodine crystals.

Centrifugal pyrocontactor

DOEpatents

Chow, Lorac S.; Leonard, Ralph A.

1993-01-01

A method for mixing and separating immiscible liquid salts and liquid metals in a centrifugal contractor. The method includes introducing the liquids into an annular mixing zone and intensely mixing the liquids using vertical vanes attached to a rotor cooperating with vertical baffles, a horizontal baffle, and bottom vanes attached to the contactor housing. The liquids enter the contactor in the range of 700-800 degrees Celsius. The liquids are separated in the rotor into a dense phase and a light phase which are discharged from the contactor.

Centrifugal pyrocontactor

DOEpatents

Chow, L.S.; Leonard, R.A.

1993-10-19

A method is described for mixing and separating immiscible liquid salts and liquid metals in a centrifugal contractor. The method includes introducing the liquids into an annular mixing zone and intensely mixing the liquids using vertical vanes attached to a rotor cooperating with vertical baffles, a horizontal baffle, and bottom vanes attached to the contactor housing. The liquids enter the contactor in the range of 700-800 degrees Celsius. The liquids are separated in the rotor into a dense phase and a light phase which are discharged from the contactor. 6 figures.

Coating processes for increasing the moisture resistance of polyurethane baffle material

NASA Technical Reports Server (NTRS)

Bilow, N.; Sawko, P.

1974-01-01

An investigation was conducted with the objective to improve the hydrolytic stability of reticulated polyurethane baffle material. This material is used in fuel tanks of aircraft and ground vehicles. The most commonly used foam of this type is hydrolytically unstable. Potential moisture barrier coatings which were evaluated include Parylene, epoxy-polysulfide, polyether based polyurethanes, polysulfides, polyolefin rubbers, and several other materials. Parylene coatings of at least 0.2 mil were found to provide the greatest improvement in hydrolytic stability.

Microstructure evolution of Al-doped zinc oxide films prepared by in-line reactive mid-frequency magnetron sputtering

NASA Astrophysics Data System (ADS)

Hong, R. J.; Jiang, X.

2006-07-01

Aluminium-doped zinc oxide (ZnO:Al or AZO) thin films were deposited on glass substrates by reactive mid-frequency (MF) magnetron sputtering from Zn/Al metallic targets. Strong (002) preferred orientation was detected by X-ray diffraction (XRD). It was observed by plan-view transmission electron microscopy (TEM) that an AZO film deposited at low substrate temperature was composed of irregular large grains; but the film prepared at high temperature was composed of moderate sized grains with a regular shape. A secondary phase of ZnO2 was also observed for the film deposited at low substrate temperature. The cross-sectional TEM study of the AZO film showed that prior to the well-aligned columnar growth an initial interfacial zone with nano crystallites were formed. The nano crystallites formed initially with a large tilt angle normal to the substrate surface and during the growth of the transition zone, the tilt angle decreased until it vanished. The evolution of the film structure is discussed in terms of evolutionary selection model and the dynamic deposition process.

An innovative small angle slot divertor concept for long pulse advanced tokamaks

NASA Astrophysics Data System (ADS)

Guo, Houyang

2017-10-01

A new Small Angle Slot (SAS) divertor is being developed in DIII-D to address the challenge of efficient divertor heat dispersal at the relatively low plasma density required for non-inductive current drive in future advanced tokamaks. SAS features a small incident angle near the plasma strike point on the divertor target plate with a progressively opening slot. SOLPS (B2-Eirene) edge code analysis finds that SAS can achieve strong plasma cooling when the strike point is placed near the small angle target plate in the slot, leading to low electron temperature Te across the entire divertor target. This is enabled by strong coupling between a gas tight slot and directed neutral recycling by the small angle target to enhance neutral buildup near the target. SOLPS analysis reveals a strong correlation between Te and D2 density at the target for various divertor configurations including the flat target, slanted target, and lower single null divertor. The strong correlation suggests that achievement of low Te may reduce essentially to identifying the divertor baffle geometry that achieves the highest target gas density at a given upstream condition. The SAS divertor concept has recently been tested in DIII-D for a range of plasma configurations and conditions with precise control of slot strike point location. In confirmation of SOLPS predictions, a sharp transition is observed when the strike point is moved to the critical outer corner of SAS. A set of Langmuir probes imbedded in SAS show that the Te radial profile, which is peaked at the strike point when it is located away from the SAS corner, becomes low across the target when the strike point is located near the corner. With further increase in density, deep-slot detachment occurs with Te 1 eV, measured by the unique DIII-D divertor Thomson Scattering diagnostic. Work supported by US DOE under DE-FC02-04ER54698.

Plastic optical fiber level measurement sensor based on side holes

NASA Astrophysics Data System (ADS)

Park, Young June; Shin, Jong-Dug; Park, Jaehee

2014-10-01

Plastic optical fiber level measurement sensor based on in-line side holes is investigated theoretically and experimentally. The sensor consists of a plastic optical fiber with in-line side holes spaced about 5 cm apart. The 0.9 diameter in-line side holes were fabricated by micro-drilling. An analytical expression of the sensor transmittance was obtained using a simple ray optics approach. The measurements of the sensor transmittance were performed with a 55 cm height Mass cylinder. Both results show that the sensor transmittance increases as the number of side holes filled with water increases. The research results indicate that the plastic optical fiber based on in-line side holes can be used for water level measurement.

Validation of High-Resolution CFD Method for Slosh Damping Extraction of Baffled Cryogenic Propellant Tanks

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeff

2016-01-01

Propellant slosh is a potential source of disturbance critical to the stability of space vehicles. The slosh dynamics are typically represented by a mechanical model of a spring-mass-damper. This mechanical model is then included in the equation of motion of the entire vehicle for Guidance, Navigation and Control analysis. A Volume-Of-Fluid (VOF) based Computational Fluid Dynamics (CFD) program developed at MSFC was applied to extract slosh damping in the baffled tank from the first principle. First the experimental data using water with sub-scale smooth wall tank were used as the baseline validation. It is demonstrated that CFD can indeed accurately predict low damping values from the smooth wall at different fill levels. The damping due to a ring baffles at different depths from the free surface was then simulated, and fairly good agreement with experimental measurement was observed. Comparison with an empirical correlation of Miles equation is also made.

Slosh Baffle Design and Test for Spherical Liquid Oxygen and Liquid Methane Propellant Tank for a Lander

NASA Technical Reports Server (NTRS)

Strahan, Alan; Hernandez, Humberto

2011-01-01

A Vertical Test Bed (VTB) is being developed to investigate exploration technologies with earth-based landing trajectories. During this activity, a concern emerged that the VTB, with large liquid tanks, could experience unstable slosh interaction between the propellant fluid motion and the control system, leading to an investigation of slosh characteristics of the VTB. As such, slosh modeling, analysis and testing were performed, that both verified models and lead to the conclusion that baffles would be required for the full-scale vehicle. Follow-on design and testing supported development of these baffles and measurement of their performance. The majority of the tests conducted, including both subscale and full, involved the use of clear tanks containing water as a reasonable substitute for the cryogenic propellants, though a few tests involved the actual liquid oxygen and methane. Along the way, some unique test and data recording methods were employed to reduce testing complexity and cost.

Research and constructive solutions on the reduction of slosh noise

NASA Astrophysics Data System (ADS)

Manta (Balas, M.; Balas, R.; Doicin, C. V.

2016-11-01

The paper presents a product design making of, over a “delicate issue” in automotive industry as slosh noise phenomena. Even though the current market tendency shows great achievements over this occurrence, in this study, the main idea is to design concepts of slosh noise baffles adapted for serial life existing fuel tanks in the automotive industry. Moreover, starting with internal and external research, going further through reversed engineering and applying own baffle technical solutions from conceptual sketches to 3D design, the paper shows the technical solutions identified as an alternative to a new development of fuel tank. Based on personal and academic experience there were identified several problematics and the possible answers based on functional analysis, in order to avoid blocking points. The idea of developing baffles adapted to already existent fuel tanks leaded to equivalent solutions analyzed from functional point of view. Once this stage is finished, a methodology will be used so as to choose the optimum solution so as to get the functional design.

Comparison of Several Methods of Predicting the Pressure Loss at Altitude Across a Baffled Aircraft-Engine Cylinder

NASA Technical Reports Server (NTRS)

Neustein, Joseph; Schafer, Louis J , Jr

1946-01-01

Several methods of predicting the compressible-flow pressure loss across a baffled aircraft-engine cylinder were analytically related and were experimentally investigated on a typical air-cooled aircraft-engine cylinder. Tests with and without heat transfer covered a wide range of cooling-air flows and simulated altitudes from sea level to 40,000 feet. Both the analysis and the test results showed that the method based on the density determined by the static pressure and the stagnation temperature at the baffle exit gave results comparable with those obtained from methods derived by one-dimensional-flow theory. The method based on a characteristic Mach number, although related analytically to one-dimensional-flow theory, was found impractical in the present tests because of the difficulty encountered in defining the proper characteristic state of the cooling air. Accurate predictions of altitude pressure loss can apparently be made by these methods, provided that they are based on the results of sea-level tests with heat transfer.

Enhanced-Adhesion Multi-Walled Carbon Nanotubes on Titanium Substrates for Stray Light Control

NASA Technical Reports Server (NTRS)

Hagopian, John; Getty, Stephanie; Quijada, Manuel

2012-01-01

Carbon nanotubes previously grown on silicon have extremely low reflectance, making them a good candidate for stray light suppression. Silicon, however, is not a good structural material for stray light components such as tubes, stops, and baffles. Titanium is a good structural material and can tolerate the 700 C nanotube growth process. The ability to grow carbon nanotubes on a titanium substrate that are ten times blacker than the current NASA state-of-the-art paints in the visible to near infrared spectra has been achieved. This innovation will allow significant improvement of stray light performance in scientific instruments or any other optical system. This innovation is a refinement of the utilization of multiwalled carbon nano tubes for stray light suppression in spaceflight instruments. The innovation is a process to make the surface darker and improve the adhesion to the substrate, improving robustness for spaceflight use. Bright objects such as clouds or ice scatter light off of instrument structures and components and make it difficult to see dim objects in Earth observations. A darker material to suppress this stray light has multiple benefits to these observations, including enabling scientific observations not currently possible, increasing observational efficiencies in high-contrast scenes, and simplifying instruments and lowering their cost by utilizing fewer stray light components and achieving equivalent performance. The prior art was to use commercially available black paint, which resulted in approximately 4% of the light being reflected (hemispherical reflectance or total integrated scatter, or TIS). Use of multiwalled carbon nanotubes on titanium components such as baffles, entrance aperture, tubes, and stops, can decrease this scattered light by a factor of ten per bounce over the 200-nm to 2,500-nm wavelength range. This can improve system stray light performance by orders of magnitude. The purpose of the innovation is to provide an enhanced stray light control capability by making a blacker surface treatment for typical stray light control components. Since baffles, stops, and tubes used in scientific observations often undergo loads such as vibration, it was critical to develop this surface treatment on structural materials. The innovation is to optimize the carbon nanotube growth for titanium, which is a strong, lightweight structural material suitable for spaceflight use. The titanium substrate carbon nanotubes are more robust than those grown on silicon and allow for easier utilization. They are darker than current surface treatments over larger angles and larger wavelength range. The primary advantage of titanium substrate is that it is a good structural material, and not as brittle as silicon.

Relationship of the functional movement screen in-line lunge to power, speed, and balance measures.

PubMed

Hartigan, Erin H; Lawrence, Michael; Bisson, Brian M; Torgerson, Erik; Knight, Ryan C

2014-05-01

The in-line lunge of the Functional Movement Screen (FMS) evaluates lateral stability, balance, and movement asymmetries. Athletes who score poorly on the in-line lunge should avoid activities requiring power or speed until scores are improved, yet relationships between the in-line lunge scores and other measures of balance, power, and speed are unknown. (1) Lunge scores will correlate with center of pressure (COP), maximum jump height (MJH), and 36.6-meter sprint time and (2) there will be no differences between limbs on lunge scores, MJH, or COP. Descriptive laboratory study. Level 3. Thirty-seven healthy, active participants completed the first 3 tasks of the FMS (eg, deep squat, hurdle step, in-line lunge), unilateral drop jumps, and 36.6-meter sprints. A 3-dimensional motion analysis system captured MJH. Force platforms measured COP excursion. A laser timing system measured 36.6-m sprint time. Statistical analyses were used to determine whether a relationship existed between lunge scores and COP, MJH, and 36.6-m speed (Spearman rho tests) and whether differences existed between limbs in lunge scores (Wilcoxon signed-rank test), MJH, and COP (paired t tests). Lunge scores were not significantly correlated with COP, MJH, or 36.6-m sprint time. Lunge scores, COP excursion, and MJH were not statistically different between limbs. Performance on the FMS in-line lunge was not related to balance, power, or speed. Healthy participants were symmetrical in lunging measures and MJH. Scores on the FMS in-line lunge should not be attributed to power, speed, or balance performance without further examination. However, assessing limb symmetry appears to be clinically relevant.

Treatment of domestic wastewater using conventional and baffled septic tanks.

PubMed

Nasr, Fayza Aly; Mikhaeil, Basem

2013-01-01

The main theme of the study was a comparative study of domestic wastewater treatment using conventional and baffled septic tanks. The septic tanks were fed continuously with domestic wastewater at three different hydraulic retention times (HRTs). The HRTs chosen were 24, 48 and 72 h with corresponding organic loads of 0.321, 0.436 and 0.885 kg chemical oxygen demand (COD) per m3 per day, respectively. The performance of the septic tanks at the three HRTs gave satisfactory results. For the conventional septic tank, COD removal was 53.4%, 56% and 65.3%, at an HRT of 24, 48 and 72 h, respectively, with residual COD of 412, 380 and 334mg/l, respectively. At HRTs of 72, 48 and 24 h, the following percentages removals were realized for: biochemical oxygen demand (BOD), 68.4%, 57, 53.5%; total suspended solid (TSS), 65.3%, 58.3, 55%; phosphorus, 29.3%, 26.9, 25.6%; total Kjeldahl nitrogen 26.8%, 20.8, 17.7%, respectively. On the contrary, ammonia concentrations increased by 7.1%, 5.2 and 4.2% under the same conditions. Consequently, the results showed that the removal of fecal coliform at all HRTs was less than one log. The two baffled septic tanks exhibited superior results at HRTs of 72, 48 and 24 h. Comparing the treated domestic wastewater quality produced by the two types of septic tanks in terms of physico-chemical and biological characteristics, better results were obtained using the two baffles type.

A conjunct near-surface spectroscopy system for fix-angle and multi-angle continuous measurements of canopy reflectance and sun-induced chlorophyll fluorescence

NASA Astrophysics Data System (ADS)

Zhang, Qian; Fan, Yifeng; Zhang, Yongguang; Chou, Shuren; Ju, Weimin; Chen, Jing M.

2016-09-01

An automated spectroscopy system, which is divided into fix-angle and multi-angle subsystems, for collecting simultaneous, continuous and long-term measurements of canopy hyper-spectra in a crop ecosystem is developed. The fix-angle subsystem equips two spectrometers: one is HR2000+ (OceanOptics) covering the spectral range 200-1100 nm with 1.0 nm spectral resolution, and another one is QE65PRO (OceanOptics) providing 0.1 nm spectral resolution within the 730-780 nm spectral range. Both spectrometers connect a cosine-corrected fiber-optic fixed up-looking to collect the down-welling irradiance and a bare fiber-optic to measure the up-welling radiance from the vegetation. An inline fiber-optic shutter FOS-2x2-TTL (OceanOptics) is used to switch between input fibers to collect the signal from either the canopy or sky at one time. QE65PRO is used to permit estimation of vegetation Sun-Induced Fluorescence (SIF) in the O2-A band. The data collection scheme includes optimization of spectrometer integration time to maximize the signal to noise ratio and measurement of instrument dark currency. The multi-angle subsystem, which can help understanding bidirectional reflectance effects, alternatively use HR4000 (OceanOptics) providing 0.1 nm spectral resolution within the 680-800 nm spectral range to measure multi-angle SIF. This subsystem additionally includes a spectrometer Unispec-DC (PPSystems) featuring both up-welling and down-welling channels with 3 nm spectral resolution covering the 300-1100 nm spectral range. Two down-looking fiber-optics are mounted on a rotating device PTU-D46 (FLIR Systems), which can rotate horizontally and vertically at 10° angular step widths. Observations can be used to calculate canopy reflectance, vegetation indices and SIF for monitoring plant physiological processes.

Investigation Of In-Line Monitoring Options At H Canyon/HB Line For Plutonium Oxide Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 thatmore » could be used for in-line analysis, and initiated a throughput benefit analysis.« less

In-line digital holography with phase-shifting Greek-ladder sieves

NASA Astrophysics Data System (ADS)

Xie, Jing; Zhang, Junyong; Zhang, Yanli; Zhou, Shenlei; Zhu, Jianqiang

2018-04-01

Phase shifting is the key technique in in-line digital holography, but traditional phase shifters have their own limitations in short wavelength regions. Here, phase-shifting Greek-ladder sieves with amplitude-only modulation are introduced into in-line digital holography, which are essentially a kind of diffraction lens with three-dimensional array diffraction-limited foci. In the in-line digital holographic experiment, we design two kinds of sieves by lithography and verify the validity of their phase-shifting function by measuring a 1951 U.S. Air Force resolution test target and three-dimensional array foci. With advantages of high resolving power, low cost, and no limitations at shorter wavelengths, phase-shifting Greek-ladder sieves have great potential in X-ray holography or biochemical microscopy for the next generation of synchrotron light sources.

Phase conjugate digital inline holography (PCDIH)

DOE PAGES

Guildenbecher, Daniel Robert; Hoffmeister, Kathryn N. Gabet; Kunzler, William Marley; ...

2018-01-12

We report digital inline holography (DIH) provides instantaneous three-dimensional (3D) measurements of diffracting objects; however, phase disturbances in the beam path can distort the imaging. In this Letter, a phase conjugate digital inline holography (PCDIH) configuration is proposed for removal of phase disturbances. Brillouin-enhanced four-wave mixing produces a phase conjugate signal that back propagates along the DIH beam path. Finally, the results demonstrate the removal of distortions caused by gas-phase shocks to recover 3D images of diffracting objects.

Responsive Image Inline Filter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freeman, Ian

2016-10-20

RIIF is a contributed module for the Drupal php web application framework (drupal.org). It is written as a helper or sub-module of other code which is part of version 8 "core Drupal" and is intended to extend its functionality. It allows Drupal to resize images uploaded through the user-facing text editor within the Drupal GUI (a.k.a. "inline images") for various browser widths. This resizing is already done foe other images through the parent "Responsive Image" core module. This code extends that functionality to inline images.

Phase conjugate digital inline holography (PCDIH)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guildenbecher, Daniel Robert; Hoffmeister, Kathryn N. Gabet; Kunzler, William Marley

We report digital inline holography (DIH) provides instantaneous three-dimensional (3D) measurements of diffracting objects; however, phase disturbances in the beam path can distort the imaging. In this Letter, a phase conjugate digital inline holography (PCDIH) configuration is proposed for removal of phase disturbances. Brillouin-enhanced four-wave mixing produces a phase conjugate signal that back propagates along the DIH beam path. Finally, the results demonstrate the removal of distortions caused by gas-phase shocks to recover 3D images of diffracting objects.

A capillary-driven micromixer: idea and fabrication

NASA Astrophysics Data System (ADS)

Lee, Chun-Te; Lee, Chun-Che

2012-10-01

Microfluidic systems have been drawing attention upon the various branches of engineering science and the allied areas within biology and biomedicine. In this paper, a fabrication of a capillary-driven micromixer using photoresist JSR and glasses is proposed. We design three types of planar capillary-driven micormixers with different sizes of baffles in the channel. Flow tests have shown that the micromixer with a baffle gap of 100 μm and space of 100 μm reaches a best mixing performance of 93% in gray-level image analysis.

Heat Exchanger With Internal Pin Elements

DOEpatents

Gerstmann, Joseph; Hannon, Charles L.

2004-01-13

A heat exchanger/heater comprising a tubular member having a fluid inlet end, a fluid outlet end and plurality of pins secured to the interior wall of the tube. Various embodiments additionally comprise a blocking member disposed concentrically inside the pins, such as a core plug or a baffle array. Also disclosed is a vapor generator employing an internally pinned tube, and a fluid-heater/heat-exchanger utilizing an outer jacket tube and fluid-side baffle elements, as well as methods for heating a fluid using an internally pinned tube.

Gas fluidized-bed stirred media mill

DOEpatents

Sadler, III, Leon Y.

1997-01-01

A gas fluidized-bed stirred media mill is provided for comminuting solid ticles. The mill includes a housing enclosing a porous fluidizing gas diffuser plate, a baffled rotor and stator, a hollow drive shaft with lateral vents, and baffled gas exhaust exit ports. In operation, fluidizing gas is forced through the mill, fluidizing the raw material and milling media. The rotating rotor, stator and milling media comminute the raw material to be ground. Small entrained particles may be carried from the mill by the gas through the exit ports when the particles reach a very fine size.

System and process for biomass treatment

DOEpatents

Dunson, Jr., James B; Tucker, III, Melvin P; Elander, Richard T; Lyons, Robert C

2013-08-20

A system including an apparatus is presented for treatment of biomass that allows successful biomass treatment at a high solids dry weight of biomass in the biomass mixture. The design of the system provides extensive distribution of a reactant by spreading the reactant over the biomass as the reactant is introduced through an injection lance, while the biomass is rotated using baffles. The apparatus system to provide extensive assimilation of the reactant into biomass using baffles to lift and drop the biomass, as well as attrition media which fall onto the biomass, to enhance the treatment process.

3D rocket combustor acoustics model

NASA Technical Reports Server (NTRS)

Priem, Richard J.; Breisacher, Kevin J.

1992-01-01

The theory and procedures for determining the characteristics of pressure oscillations in rocket engines with prescribed burning rate oscillations are presented. Analyses including radial and hub baffles and absorbers can be performed in one, two, or three dimensions. Pressure and velocity oscillations calculated using this procedure are presented for the SSME to show the influence of baffles and absorbers on the burning rate oscillations required to achieve neutral stability. Comparisons are made between the results obtained utilizing 1D, 2D, and 3D assumption with regards to capturing the physical phenomena of interest and computational requirements.

How temperature determines formation of maghemite nanoparticles

NASA Astrophysics Data System (ADS)

Girod, Matthias; Vogel, Stefanie; Szczerba, Wojciech; Thünemann, Andreas F.

2015-04-01

We report on the formation of polymer-stabilized superparamagnetic single-core and multi-core maghemite nanoparticles. The particle formation was carried out by coprecipitation of Fe(II) and Fe(III) sulfate in a continuous aqueous process using a micromixer system. Aggregates containing 50 primary particles with sizes of 2 nm were formed at a reaction temperature of 30 °C. These particles aggregated further with time and were not stable. In contrast, stable single-core particles with a diameter of 7 nm were formed at 80 °C as revealed by small-angle X-ray scattering (SAXS) coupled in-line with the micromixer for particle characterization. X-ray diffraction and TEM confirmed the SAXS results. X-ray absorption near-edge structure spectroscopy (XANES) identified the iron oxide phase as maghemite.

Single-shot dual-wavelength in-line and off-axis hybrid digital holography

NASA Astrophysics Data System (ADS)

Wang, Fengpeng; Wang, Dayong; Rong, Lu; Wang, Yunxin; Zhao, Jie

2018-02-01

We propose an in-line and off-axis hybrid holographic real-time imaging technique. The in-line and off-axis digital holograms are generated simultaneously by two lasers with different wavelengths, and they are recorded using a color camera with a single shot. The reconstruction is carried using an iterative algorithm in which the initial input is designed to include the intensity of the in-line hologram and the approximate phase distributions obtained from the off-axis hologram. In this way, the complex field in the object plane and the output by the iterative procedure can produce higher quality amplitude and phase images compared to traditional iterative phase retrieval. The performance of the technique has been demonstrated by acquiring the amplitude and phase images of a green lacewing's wing and a living moon jellyfish.

Should in-line filters be used in peripheral intravenous catheters to prevent infusion-related phlebitis? A systematic review of randomized controlled trials.

PubMed

Niël-Weise, Barbara S; Stijnen, Theo; van den Broek, Peterhans J

2010-06-01

In this systematic review, we assessed the effect of in-line filters on infusion-related phlebitis associated with peripheral IV catheters. The study was designed as a systematic review and meta-analysis of randomized controlled trials. We used MEDLINE and the Cochrane Controlled Trial Register up to August 10, 2009. Two reviewers independently assessed trial quality and extracted data. Data on phlebitis were combined when appropriate, using a random-effects model. The impact of the risk of phlebitis in the control group (baseline risk) on the effect of in-line filters was studied by using meta-regression based on the bivariate meta-analysis model. The quality of the evidence was determined by using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) method. Eleven trials (1633 peripheral catheters) were included in this review to compare the effect of in-line filters on the incidence of phlebitis in hospitalized patients. Baseline risks across trials ranged from 23% to 96%. Meta-analysis of all trials showed that in-line filters reduced the risk of infusion-related phlebitis (relative risk, 0.66; 95% confidence interval, 0.43-1.00). This benefit, however, is very uncertain, because the trials had serious methodological shortcomings and meta-analysis revealed marked unexplained statistical heterogeneity (P < 0.0000, I(2) = 90.4%). The estimated benefit did not depend on baseline risk. In-line filters in peripheral IV catheters cannot be recommended routinely, because evidence of their benefit is uncertain.

Analysis and Synthesis of Pseudo-Periodic[InlineEquation not available: see fulltext.]-Like Noise by Means of Wavelets with Applications to Digital Audio

NASA Astrophysics Data System (ADS)

Polotti, Pietro; Evangelista, Gianpaolo

2001-12-01

Voiced musical sounds have nonzero energy in sidebands of the frequency partials. Our work is based on the assumption, often experimentally verified, that the energy distribution of the sidebands is shaped as powers of the inverse of the distance from the closest partial. The power spectrum of these pseudo-periodic processes is modeled by means of a superposition of modulated[InlineEquation not available: see fulltext.] components, that is, by a pseudo-periodic[InlineEquation not available: see fulltext.]-like process. Due to the fundamental selfsimilar character of the wavelet transform,[InlineEquation not available: see fulltext.] processes can be fruitfully analyzed and synthesized by means of wavelets. We obtain a set of very loosely correlated coefficients at each scale level that can be well approximated by white noise in the synthesis process. Our computational scheme is based on an orthogonal[InlineEquation not available: see fulltext.]-band filter bank and a dyadic wavelet transform per channel. The[InlineEquation not available: see fulltext.] channels are tuned to the left and right sidebands of the harmonics so that sidebands are mutually independent. The structure computes the expansion coefficients of a new orthogonal and complete set of harmonic-band wavelets. The main point of our scheme is that we need only two parameters per harmonic in order to model the stochastic fluctuations of sounds from a pure periodic behavior.

Reducing measurement uncertainty drives the use of multiple technologies for supporting metrology

NASA Astrophysics Data System (ADS)

Banke, Bill, Jr.; Archie, Charles N.; Sendelbach, Matthew; Robert, Jim; Slinkman, James A.; Kaszuba, Phil; Kontra, Rick; DeVries, Mick; Solecky, Eric P.

2004-05-01

Perhaps never before in semiconductor microlithography has there been such an interest in the accuracy of measurement. This interest places new demands on our in-line metrology systems as well as the supporting metrology for verification. This also puts a burden on the users and suppliers of new measurement tools, which both challenge and complement existing manufacturing metrology. The metrology community needs to respond to these challenges by using new methods to assess the fab metrologies. An important part of this assessment process is the ability to obtain accepted reference measurements as a way of determining the accuracy and Total Measurement Uncertainty (TMU) of an in-line critical dimension (CD). In this paper, CD can mean any critical dimension including, for example, such measures as feature height or sidewall angle. This paper describes the trade-offs of in-line metrology systems as well as the limitations of Reference Measurement Systems (RMS). Many factors influence each application such as feature shape, material properties, proximity, sampling, and critical dimension. These factors, along with the metrology probe size, interaction volume, and probe type such as e-beam, optical beam, and mechanical probe, are considered. As the size of features shrinks below 100nm some of the stalwarts of reference metrology come into question, such as the electrically determined transistor gate length. The concept of the RMS is expanded to show how multiple metrologies are needed to achieve the right balance of accuracy and sampling. This is also demonstrated for manufacturing metrology. Various comparisons of CDSEM, scatterometry, AFM, cross section SEM, electrically determined CDs, and TEM are shown. An example is given which demonstrates the importance in obtaining TMU by balancing accuracy and precision for selecting manufacturing measurement strategy and optimizing manufacturing metrology. It is also demonstrated how the necessary supporting metrology will bring together formerly unlinked technology fields requiring new measurement science. The emphasis on accuracy will increase the importance and role of NIST and similar metrology organizations in supporting the semiconductor industry in this effort.

Evaluation of Boundary Dam spillway using an Autonomous Sensor Fish Device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Z. D.; Duncan, J. P.; Arnold, J. L.

Fish passage conditions over spillways are important for the operations of hydroelectric dams because spillways are usually considered as a common alternative passage route to divert fish from the turbines. The objectives of this study were to determine the relative potential of fish injury during spillway passage both before and after the installation of baffle blocks at Boundary Dam, and to provide validation data for a model being used to predict total dissolved gas levels. Sensor Fish were deployed through a release system mounted on the face of the dam in the forebay. Three treatments, based on the lateral positionmore » on the spillway, were evaluated for both the baseline and post-modification evaluations: Left Middle, Right Middle, and Right. No significant acceleration events were detected in the forebay, gate, or transition regions for any release location; events were only observed on the chute and in the tailrace. Baseline acceleration events observed in the chute region were all classified as strikes, whereas post-modification events included strike and shear on the chute. While the addition of baffle blocks increased the number of significant events observed on the spillway chute, overall fewer events were observed in the tailrace post-modification. Analysis of lateral positioning of passage indicated that the Right Middle treatment was potentially less injurious to fish based on relative frequency of significant events at each location. The construction of baffle blocks on the spillway visibly changed the flow regime. Prior to installation the flow jet was relatively thin, impacting the tailrace as a coherent stream that plunged deeply, possibly contributing to total dissolved gas production. Following baffle block construction, the discharge jet was more fragmented, potentially disrupting the plunge depth and decreasing the time that bubbles would be at depth in the plunge pool. The results in this study support the expected performance of the modified spillway chute: the addition of the baffle blocks generally lessened the depth and impact of entry. This study provides information that can be used to help design and operate spillways for improving fish passage conditions.« less

Low-Power Embedded DSP Core for Communication Systems

NASA Astrophysics Data System (ADS)

Tsao, Ya-Lan; Chen, Wei-Hao; Tan, Ming Hsuan; Lin, Maw-Ching; Jou, Shyh-Jye

2003-12-01

This paper proposes a parameterized digital signal processor (DSP) core for an embedded digital signal processing system designed to achieve demodulation/synchronization with better performance and flexibility. The features of this DSP core include parameterized data path, dual MAC unit, subword MAC, and optional function-specific blocks for accelerating communication system modulation operations. This DSP core also has a low-power structure, which includes the gray-code addressing mode, pipeline sharing, and advanced hardware looping. Users can select the parameters and special functional blocks based on the character of their applications and then generating a DSP core. The DSP core has been implemented via a cell-based design method using a synthesizable Verilog code with TSMC 0.35[InlineEquation not available: see fulltext.]m SPQM and 0.25[InlineEquation not available: see fulltext.]m 1P5M library. The equivalent gate count of the core area without memory is approximately 50 k. Moreover, the maximum operating frequency of a[InlineEquation not available: see fulltext.] version is 100 MHz (0.35[InlineEquation not available: see fulltext.]m) and 140 MHz (0.25[InlineEquation not available: see fulltext.]m).

In-line agglomeration degree estimation in fluidized bed pellet coating processes using visual imaging.

PubMed

Mehle, Andraž; Kitak, Domen; Podrekar, Gregor; Likar, Boštjan; Tomaževič, Dejan

2018-05-09

Agglomeration of pellets in fluidized bed coating processes is an undesirable phenomenon that affects the yield and quality of the product. In scope of PAT guidance, we present a system that utilizes visual imaging for in-line monitoring of the agglomeration degree. Seven pilot-scale Wurster coating processes were executed under various process conditions, providing a wide spectrum of process outcomes. Images of pellets were acquired during the coating processes in a contactless manner through an observation window of the coating apparatus. Efficient image analysis methods were developed for automatic recognition of discrete pellets and agglomerates in the acquired images. In-line obtained agglomeration degree trends revealed the agglomeration dynamics in distinct phases of the coating processes. We compared the in-line estimated agglomeration degree in the end point of each process to the results obtained by the off-line sieve analysis reference method. A strong positive correlation was obtained (coefficient of determination R 2 =0.99), confirming the feasibility of the approach. The in-line estimated agglomeration degree enables early detection of agglomeration and provides means for timely interventions to retain it in an acceptable range. Copyright © 2018 Elsevier B.V. All rights reserved.

Miniaturized cathodic arc plasma source

DOEpatents

Anders, Andre; MacGill, Robert A.

2003-04-15

A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

Development of Semi-Empirical Damping Equation for Baffled Tank with Oblate Spheroidal Dome

NASA Technical Reports Server (NTRS)

Yang, H. Q.; West, Jeff; Brodnick, Jacob; Eberhart, Chad

2016-01-01

Propellant slosh is a potential source of disturbance that can significantly impact the stability of space vehicles. The slosh dynamics are typically represented by a mechanical model of a spring-mass-damper. This mechanical model is then included in the equation of motion of the entire vehicle for Guidance, Navigation and Control analysis. The typical parameters required by the mechanical model include natural frequency of the slosh, slosh mass, slosh mass center location, and the critical damping ratio. A fundamental study has been undertaken at NASA MSFC to understand the fluid damping physics from a ring baffle in the barrel section of a propellant tank. An asymptotic damping equation and CFD blended equation have been derived by NASA MSFC team to complement the popularly used Miles equation at different flow regimes. The new development has found success in providing a nonlinear damping model for the Space Launch System. The purpose of this study is to further extend the semi-empirical damping equations into the oblate spheroidal dome section of the propellant tanks. First, previous experimental data from the spherical baffled tank are collected and analyzed. Several methods of taking the dome curvature effect, including a generalized Miles equation, area projection method, and equalized fill height method, are assessed. CFD simulation is used to shed light on the interaction of vorticity around the baffle with the locally curved wall and liquid-gas interface. The final damping equation will be validated by a recent subscale test with an oblate spheroidal dome conducted at NASA MSFC.

A Strategy of Suppressing the Underground Impact Scattered Current in Power Grid by Using Insulation Baffle

NASA Astrophysics Data System (ADS)

Zhan, Qinghua; Chen, Zhucheng; Li, Hongtao; Liu, Yijun; Mei, Cheng; He, Zhijie

2017-05-01

In order to solve the accidents happened in the ponds or other special places around the tower which were caused by the diffusion current after lightning stroke the transmission tower, the protection measures for the problem tower in the area of Guangdong Province which occurred dead fish in the pond in thunderstorm weather were studied in this paper. The COMSOL mutiphysics simulation software was used in order to calculate the electromagnetic environment of the diffusion situation by grounding device after lightning stroke the power transmission tower. Study concluded that the safe distance between the fish pond and grounding device of transmission tower is 14 meter. The effects of the length and depth or stayed a gap of the insulation baffle on the fish in the fish pond were discussed. The protection method of the insulation baffle has important practical significance to the protection of the grounding device for diffusion current, and can provide some engineering guidance and basis for the grounding arrangement and transformation of the high voltage transmission line tower.

Example study for granular bioreactor stratification: Three-dimensional evaluation of a sulfate-reducing granular bioreactor

PubMed Central

Hao, Tian-wei; Luo, Jing-hai; Su, Kui-zu; Wei, Li; Mackey, Hamish R.; Chi, Kun; Chen, Guang-Hao

2016-01-01

Recently, sulfate-reducing granular sludge has been developed for application in sulfate-laden water and wastewater treatment. However, little is known about biomass stratification and its effects on the bioprocesses inside the granular bioreactor. A comprehensive investigation followed by a verification trial was therefore conducted in the present work. The investigation focused on the performance of each sludge layer, the internal hydrodynamics and microbial community structures along the height of the reactor. The reactor substratum (the section below baffle 1) was identified as the main acidification zone based on microbial analysis and reactor performance. Two baffle installations increased mixing intensity but at the same time introduced dead zones. Computational fluid dynamics simulation was employed to visualize the internal hydrodynamics. The 16S rRNA gene of the organisms further revealed that more diverse communities of sulfate-reducing bacteria (SRB) and acidogens were detected in the reactor substratum than in the superstratum (the section above baffle 1). The findings of this study shed light on biomass stratification in an SRB granular bioreactor to aid in the design and optimization of such reactors. PMID:27539264

Indicators for technological, environmental and economic sustainability of ozone contactors.

PubMed

Zhang, Jie; Tejada-Martinez, Andres E; Lei, Hongxia; Zhang, Qiong

2016-09-15

Various studies have attempted to improve disinfection efficiency as a way to improve the sustainability of ozone disinfection which is a critical unit process for water treatment. Baffling factor, CT10, and log-inactivation are commonly used indicators for quantifying disinfection credits. However the applicability of these indicators and the relationship between these indicators have not been investigated in depth. This study simulated flow, tracer transport, and chemical species transport in a full-scale ozone contactor operated by the City of Tampa Water Department and six other modified designs using computational fluid dynamics (CFD). Through analysis of the simulation results, we found that baffling factor and CT10 are not optimal indicators of disinfection performance. We also found that the relationship between effluent CT obtained from CT transport simulation and baffling factor depends on the location of ozone release. In addition, we analyzed the environmental and economic impacts of ozone contactor designs and upgrades and developed a composite indicator to quantify the sustainability in technological, environmental and economic dimensions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simultaneous Bioreduction of Multiple Oxidized Contaminants Using a Membrane Biofilm Reactor.

PubMed

Li, Haixiang; Lin, Hua; Xu, Xiaoyin; Jiang, Minmin; Chang, Chein-Chi; Xia, Siqing

2017-02-01

  This study tests a hydrogen-based membrane biofilm reactor (MBfR) to investigate simultaneous bioreduction of selected oxidized contaminants, including nitrate (-N), sulfate (), bromate (), chromate (Cr(VI)) and para-chloronitrobenzene (p-CNB). The experiments demonstrate that MBfR can achieve high performance for contaminants bioreduction to harmless or immobile forms in 240 days, with a maximum reduction fluxes of 0.901 g -N/m2·d, 1.573 g /m2·d, 0.009 g /m2·d, 0.022 g Cr(VI)/m2·d, and 0.043 g p-CNB/m2·d. Increasing H2 pressure and decreasing influent surface loading enhanced removal efficiency of the reactor. Flux analysis indicates that nitrate and sulfate reductions competed more strongly than , Cr(VI) and p-CNB reduction. The average H2 utilization rate, H2 flux, and H2 utilization efficiency of the reactor were 0.026 to 0.052 mg H2/cm3·d, 0.024 to 0.046 mg H2/cm2·d, and 97.5% to 99.3% (nearly 100%). Results show the hydrogen-based MBfR may be suitable for removing multiple oxidized contaminants in drinking water or groundwater.

Miniaturized fiber inline Fabry-Perot interferometer for chemical sensing.

DOT National Transportation Integrated Search

2010-01-01

This paper demonstrates the chemical sensing capability of a miniaturized fiber inline Fabry-Prot sensor fabricated by femtosecond : laser. Its accessible cavity enables the device to measure the refractive index within the cavity. The refractive i...

An Energy-Based Similarity Measure for Time Series

NASA Astrophysics Data System (ADS)

Boudraa, Abdel-Ouahab; Cexus, Jean-Christophe; Groussat, Mathieu; Brunagel, Pierre

2007-12-01

A new similarity measure, called SimilB, for time series analysis, based on the cross-[InlineEquation not available: see fulltext.]-energy operator (2004), is introduced. [InlineEquation not available: see fulltext.] is a nonlinear measure which quantifies the interaction between two time series. Compared to Euclidean distance (ED) or the Pearson correlation coefficient (CC), SimilB includes the temporal information and relative changes of the time series using the first and second derivatives of the time series. SimilB is well suited for both nonstationary and stationary time series and particularly those presenting discontinuities. Some new properties of [InlineEquation not available: see fulltext.] are presented. Particularly, we show that [InlineEquation not available: see fulltext.] as similarity measure is robust to both scale and time shift. SimilB is illustrated with synthetic time series and an artificial dataset and compared to the CC and the ED measures.

Inline skating for balance and strength promotion in children during physical education.

PubMed

Muehlbauer, Thomas; Kuehnen, Matthias; Granacher, Urs

2013-12-01

Deficiencies in balance and strength are common in children and they may lead to injuries. This study investigated the effects of inline skating exercise on balance and strength performance in healthy children. Twenty 11-12-year-old children (8 girls, 12 boys) were assigned to an intervention (n = 10) or a control (n = 10) group. Participants in the intervention group underwent a 4-week inline skating program (2 times/week, 90 min. each) integrated in their physical education lessons. Balance and strength were measured using the Star Excursion Balance test and the countermovement jump test. As compared to the control group, the intervention group significantly improved balance (17-48%, Cohen's d = 0.00-1.49) and jump height (8%, Cohen's d = 0.48). In children, inline skating is a safe, feasible (90% adherence rate), and effective program that can be integrated in physical education lessons to promote balance and strength.

Surgical Repair of an Impalement Genital Injury from an Inline Skating Accident in a 7-Year-Old Prepubertal Girl: A Case Report.

PubMed

Csorba, Roland; Engel, Joerg B; Wieg, Christian

2017-02-01

In girls who present with vaginal trauma, sexual abuse is often the primary diagnosis. The differential diagnosis must include patterns and the mechanism of injury that differentiate accidental injuries from inflicted trauma. A 7-year-old prepubertal girl presented to the emergency department with genital bleeding after a serious accidental impaling injury from inline skating. After rapid abduction of the legs and a fall onto the blade of an inline skate this child incurred an impaling genital injury consistent with an accidental mechanism. The dramatic genital injuries when repaired healed with almost imperceptible residual evidence of previous trauma. To our knowledge, this case report represents the first in the medical literature of an impaling vaginal trauma from an inline skate and describes its clinical and surgical management. Copyright © 2016 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

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.

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.

Combustion heater for oil shale

DOEpatents

Mallon, R.; Walton, O.; Lewis, A.E.; Braun, R.

1983-09-21

A combustion heater for oil shale heats particles of spent oil shale containing unburned char by burning the char. A delayed fall is produced by flowing the shale particles down through a stack of downwardly sloped overlapping baffles alternately extending from opposite sides of a vertical column. The delayed fall and flow reversal occurring in passing from each baffle to the next increase the residence time and increase the contact of the oil shale particles with combustion supporting gas flowed across the column to heat the shale to about 650 to 700/sup 0/C for use as a process heat source.

Combustion heater for oil shale

DOEpatents

Mallon, Richard G.; Walton, Otis R.; Lewis, Arthur E.; Braun, Robert L.

1985-01-01

A combustion heater for oil shale heats particles of spent oil shale containing unburned char by burning the char. A delayed fall is produced by flowing the shale particles down through a stack of downwardly sloped overlapping baffles alternately extending from opposite sides of a vertical column. The delayed fall and flow reversal occurring in passing from each baffle to the next increase the residence time and increase the contact of the oil shale particles with combustion supporting gas flowed across the column to heat the shale to about 650.degree.-700.degree. C. for use as a process heat source.

Calculations of combustion response profiles and oscillations

NASA Technical Reports Server (NTRS)

Priem, Richard J.; Breisacher, Kevin J.

1993-01-01

The theory and procedures for determining the characteristics of pressure oscillations in rocket engines with prescribed burning rate oscillations are presented. Pressure and velocity oscillations calculated using this procedure are presented for the Space Shuttle Main Engine (SSME) to show the influence of baffles and absorbers on the burning rate oscillations required to achieve neutral stability. Results of calculations to determine local combustion responses using detailed physical models for injection, atomization, and vaporization with gas phase oscillations in baffled and unbaffled SSME combustors are presented. The contributions of the various physical phenomena occurring in a combustor to oscillations in combustion response were determined.

The 3D rocket combustor acoustics model

NASA Technical Reports Server (NTRS)

Priem, Richard J.; Breisacher, Kevin J.

1992-01-01

The theory and procedures for determining the characteristics of pressure oscillations in rocket engines with prescribed burning rate oscillations are presented. Analyses including radial and hub baffles and absorbers can be performed in one, two, and three dimensions. Pressure and velocity oscillations calculated using this procedure are presented for the SSME to show the influence of baffles and absorbers on the burning rate oscillations required to achieve neutral stability. Comparisons are made between the results obtained utilizing 1-D, 2-D, and 3-D assumptions with regards to capturing the physical phenomena of interest and computational requirements.

Study of particle evolution from Composition B-3 detonation by time-resolved small angle x-ray scattering

NASA Astrophysics Data System (ADS)

Huber, R.; Podlesak, D.; Dattelbaum, D.; Firestone, M.; Gustavsen, R.; Jensen, B.; Ringstrand, B.; Watkins, E.; Bagge-Hansen, M.; Hodgin, R.; Lauderbach, L.; Willey, T.; van Buuren, T.; Graber, T.; Rigg, P.; Sinclair, N.; Seifert, S.

2017-06-01

High explosive (HE) detonations produce an assortment of gases (CO, CO2, N2) and solid carbon products (nanodiamond, graphite). The evolution of solid carbon particles, within the chemical reaction zone, help to propel the detonation wave forward. Due to the violent nature and short reaction times during HE detonations, experimental observation are limited. Through time-resolved small angle x-ray scattering (TRSAXS) we are able to observed nanocarbon formation on nanosecond time scales. This TRSAXS setup is the first of its kind in the United States at Argonne National Laboratory at the Advanced Photon Source in the Dynamic Compression Sector. From the empirical and analytical analysis of the x-ray scattering of an in-line detonation we are able to temporally follow morphology and size. Two detonation geometries were studied for the HE Comp B-3 (40% TNT/60% RDX), producing steady and overdriven conditions. Steady wave particle evolution plateaued by 2 microseconds, where overdriven condition particle size decreases at the collision of the two shock fronts then plateaus. Post detonation soot is also analyzed to confirm size and shape of nanocarbon formation from Comp B-3 detonations. LA-UR-17-21443.

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

Demonstration of an ultra-wideband optical fiber inline polarizer with metal nano-grid on the fiber tip.

PubMed

Lin, Yongbin; Guo, Junpeng; Lindquist, Robert G

2009-09-28

Dramatic increase in the bandwidth of optical fiber inline polarizer can be achieved by using metal nano-grid on the fiber tip. However, high extinction ratio of such fiber polarizer requires high spatial frequency metal nano girds with high aspect ratio on the small area of optical fiber tip. We report the development of a nano-fabrication process on the optical fiber tip, and the design and realization of the first ultra-wideband fiber inline polarization device with Au nano gird fabricated on a single mode optical fiber end face.

Fiber in-line Mach-Zehnder interferometer based on an inner air-cavity for high-pressure sensing.

PubMed

Talataisong, W; Wang, D N; Chitaree, R; Liao, C R; Wang, C

2015-04-01

We demonstrate a fiber in-line Mach-Zehnder interferometer based on an inner air-cavity with open micro-channel for high-pressure sensing applications. The inner air-cavity is fabricated by combining femtosecond laser micromachining and the fusion splicing technique. The micro-channel is drilled on the top of the inner air-cavity to allow the high-pressure gas to flow in. The fiber in-line device is miniature, robust, and stable in operation and exhibits a high pressure sensitivity of ∼8,239  pm/MPa.

Partially coherent lensfree tomographic microscopy⋄

PubMed Central

Isikman, Serhan O.; Bishara, Waheb; Ozcan, Aydogan

2012-01-01

Optical sectioning of biological specimens provides detailed volumetric information regarding their internal structure. To provide a complementary approach to existing three-dimensional (3D) microscopy modalities, we have recently demonstrated lensfree optical tomography that offers high-throughput imaging within a compact and simple platform. In this approach, in-line holograms of objects at different angles of partially coherent illumination are recorded using a digital sensor-array, which enables computing pixel super-resolved tomographic images of the specimen. This imaging modality, which forms the focus of this review, offers micrometer-scale 3D resolution over large imaging volumes of, for example, 10–15 mm3, and can be assembled in light weight and compact architectures. Therefore, lensfree optical tomography might be particularly useful for lab-on-a-chip applications as well as for microscopy needs in resource-limited settings. PMID:22193016

Optical design of the STAR-X telescope

NASA Astrophysics Data System (ADS)

Saha, Timo T.; Zhang, William W.; McClelland, Ryan S.

2017-08-01

Top-level science objectives of the Survey and Time-domain Astrophysical Research eXplorer (STAR-X) include: investigations of most violent explosions in the universe, study of growth of black holes across cosmic time and mass scale, and measure how structure formation heats majority of baryons in the universe. To meet these objectives, the STAR-X telescope requires a field of view of about 1 square-degree, an angular resolution of 5 arc-seconds or better across large part of the field of view. The on-axis effective area at 1 keV should be about 2,000 cm2 . Payload cost and launch considerations limit the outer diameter, focal length, and mass to 1.3 meters, 5 meters, and 250 kilograms, respectively. Telescope design is based on a segmented meta-shell approach we have developed at Goddard Space Flight Center. The telescope mirror shells are divided into segments. Individual shells are nested inside each other to meet the effective area requirements in 0.5 - 6.0 keV range. We consider Wolter-Schwarzschild, and Modified-WolterSchwarzschild telescopes. These designs offer an excellent PSF over a large field of view. Nested shells are vulnerable to stray light problems. We have designed a multi-component baffle system to eliminate direct and single-reflection light paths inside the mirror assembly. Large numbers of internal and external baffles are required to prevent stray rays from reaching the focal plane. We have developed a simple ray-trace tool to determine the dimensions and locations of the baffles. In this paper, we present the results of our trade studies, baffle design studies, and optical performance analyses of the STAR-X telescope.

Design of the STAR-X Telescope

NASA Technical Reports Server (NTRS)

Saha, Timo T.; Zhang, William W.; McClelland, Ryan S.

2017-01-01

Top-level science goals of the Survey and Time-domain Astrophysical Research eXplorer (STAR-X) include: investigations of most violent explosions in the universe, study of growth of black holes across cosmic time and mass scale, and measure how structure formation heats majority of baryons in the universe. To meet these goals, the field-of-view of the telescope should be about 1 square-degree, the angular resolution should be 5 arc-seconds or below across large part of the field-of-view. The on-axis effective area at 1 KeV should be about 2,000 sq cm. Payload cost and launch considerations limit the outer diameter, focal length, and mass to 1.3 meters, 5 meters, and 250 kilograms, respectively. Telescope design is based on a segmented meta-shell approach we have developed at Goddard Space Flight Center for the STAR-X telescope. The telescope shells are divided into 30-degree segments. Individual telescopes and meta-shells are nested inside each other to meet the effective area requirements in 0.5 - 6.0 KeV range. We consider Wolter-Schwarzschild, and Modified-Wolter-Schwarzschild telescope designs as basic building blocks of the nested STAR-X telescope. These designs offer an excellent resolution over a large field of views. Nested telescopes are vulnerable to stray light problems. We have designed a multi-component baffle system to eliminate direct and single-reflection light paths inside the telescopes. Large number of internal and external baffle vane structures are required to prevent stray rays from reaching the focal plane. We have developed a simple ray-trace based tool to determine the dimensions and locations of the baffles. In this paper, we present the results of our trade studies, baffle design studies, and optical performance analyses of the STAR-X telescope.

Optical Design of the STAR-X Telescope

NASA Technical Reports Server (NTRS)

Saha, Timo T.; Zhang, William W.; McClelland, Ryan S.

2017-01-01

Top-level science goals of the Survey and Time-domain Astrophysical Research eXplorer (STAR-X) include: investigations of most violent explosions in the universe, study of growth of black holes across cosmic time and mass scale, and measure how structure formation heats majority of baryons in the universe. To meet these goals, the field-of-view of the telescope should be about 1 square-degree, the angular resolution should be 5 arc-seconds or below across large part of the field-of-view. The on-axis effective area at 1 KeV should be about 2,000 sq cm. Payload cost and launch considerations limit the outer diameter, focal length, and mass to 1.3 meters, 5 meters, and 250 kilograms, respectively. Telescope design is based on a segmented meta-shell approach we have developed at Goddard Space Flight Center for the STAR-X telescope. The telescope shells are divided into 30-degree segments. Individual telescopes and meta-shells are nested inside each other to meet the effective area requirements in 0.5 - 6.0 KeV range. We consider Wolter-Schwarzschild, and Modified-Wolter-Schwarzschild telescope designs as basic building blocks of the nested STAR-X telescope. These designs offer an excellent resolution over a large field of views. Nested telescopes are vulnerable to stray light problems. We have designed a multi-component baffle system to eliminate direct and single-reflection light paths inside the telescopes. Large number of internal and external baffle vane structures are required to prevent stray rays from reaching the focal plane. We have developed a simple ray-trace based tool to determine the dimensions and locations of the baffles. In this paper, we present the results of our trade studies, baffle design studies, and optical performance analyses of the STAR-X telescope.

Kinetic study of treatment of wastewater contains food preservative agent by anaerobic baffled reactor : An overview

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sumantri, Indro; Purwanto,; Budiyono

The characteristic of wastewater of food industries with preservative substances is high content of organic substances, degradable and high total suspended solid. High organic content in this waste forced the treatment is biologically and pointed out to anaerobic treatment. Anaerobic showed the better performance of degradation than aerobic for high content organic and also for toxic materials. During that day the treatment of food wastewater is aerobically which is high consume of energy required and high volume of sludge produced. The advantage of anaerobic is save high energy, less product of sludge, less requirement of nutrients of microorganism and highmore » efficiency reduction of organic load. The high efficiency of reduction will reduce the load of further treatment, so that, the threshold limit based on the regulation would be easy to achieve. Research of treatment of wastewater of food industries would be utilized by both big scale industries and small industries using addition of preservative substances. The type reactor of anaerobic process is anaerobic baffled reactor that will give better contact between wastewater and microorganism in the sludge. The variables conducted in this research are the baffled configuration, sludge height, preservative agent contents, hydralic retention time and influence of micro nutrients. The respons of this research are the COD effluent, remaining preservative agent, pH, formation of volatile fatty acid and total suspended solid. The result of this research is kinetic model of the anaerobic baffled reactor, reaction kinetic of preservative agent degradation and technology of treatment wastewater contains preservative agent. The benefit of this research is to solve the treatment of wastewater of food industries with preservative substance in order to achieve wastewater limit regulation and also to prevent the environmental deterioration.« less

Inactivation of Escherichia coli in a baffled pond with attached growth: treating anaerobic effluent under the Sahelian climate.

PubMed

Moumouni, D A; Andrianisa, H A; Konaté, Y; Ndiaye, A; Maïga, A H

2016-01-01

This study aimed to investigate and understand the zero-level detection of Escherichia coli (E. coli) at the outlet of an improved waste stabilization pond. Wastewaters were collected from the International Institute for Water and Environmental Engineering (2iE) campus and were subjected to biological treatment. The system included two-stage Anaerobic Reactors followed by a Baffled Pond (AR-BP) with recycled plastic media as a medium for attached growth and a control pond (CP). Three vertical baffles were installed, giving four compartments in the baffled pond (BP). The research was conducted on the pilot scale from March to July 2014, by monitoring E. coli, pH, temperature, dissolved oxygen (DO) and chlorophyll-a in each compartment and at different depths. The results show that E. coli concentrations were lower in top layers of all compartments with an undetectable level in the last compartment up to 0.60 m deep. E. coli mean removal efficiencies and decay rates were achieved by significant difference in BP (4.5 log-units, 9.1 day(-1)) and CP (1.1 log-units, 1.1 day(-1)). Higher values of pH (≥9), temperature (≥32°C), DO (≥ 8 mg/L) and chlorophyll-a (≥ 1000 µg/L) were observed at the surface of BP, whereas lower values were shown at the bottom. Sedimentation combined with the synergetic effects of the physicochemical parameters and environmental factors would be responsible for the inactivation of E. coli in BP. It was concluded that the AR-BP could be applied as an alternative low-cost wastewater treatment technology for developing countries and recommended for reuse of their effluent for restricted peri-urban irrigation.

Evaluation of decentralized treatment of sewage employing Upflow Septic Tank/Baffled Reactor (USBR) in developing countries.

PubMed

Sabry, Tarek

2010-02-15

A new concept for a low-cost modified septic tank, named Upflow Septic Tank/Baffled Reactor (USBR), was constructed and tested in a small village in Egypt. During almost one year of continuous operation and monitoring, this system was found to have very satisfactory removal results, where the average results of COD, BOD, and TSS removal efficiencies were 84%, 81%, and 89%, respectively, and the results of the experiment proved that the second compartment (Anaerobic Baffled Reactor) was the main treatment unit in removing the pollutants during the start-up period and at the very early steady-state stage. However, after this period and during the steady-state operation conditions, the second compartment served as a polishing step. Also, it was observed that the USBR system was not affected by the imposed shock loads at the peak flow and organic periods. The results showed that the system is slightly influenced by the drop in the temperature. Decreasing in BOD and COD removal by factor of 9% was observed, when temperature decreases from the average of 35 degrees C in summer time (for the first 127 days) to the average of 22 degrees C in winter time (between day 252 and day 280). Whereas, the TSS removals were not affected by the drop in temperature. The results of the sewage flow variations during one year of operation were compared with Goodrich Formula to see the applicability of this equation in rural developing countries. MAIN FINDING OF THE WORK: The Upflow Septic Tank/Baffled Reactor system could become a promising alternative to the conventional treatment plants in rural developing countries.

Kinetic study of treatment of wastewater contains food preservative agent by anaerobic baffled reactor : An overview

NASA Astrophysics Data System (ADS)

Sumantri, Indro; Purwanto, Budiyono

2015-12-01

The characteristic of wastewater of food industries with preservative substances is high content of organic substances, degradable and high total suspended solid. High organic content in this waste forced the treatment is biologically and pointed out to anaerobic treatment. Anaerobic showed the better performance of degradation than aerobic for high content organic and also for toxic materials. During that day the treatment of food wastewater is aerobically which is high consume of energy required and high volume of sludge produced. The advantage of anaerobic is save high energy, less product of sludge, less requirement of nutrients of microorganism and high efficiency reduction of organic load. The high efficiency of reduction will reduce the load of further treatment, so that, the threshold limit based on the regulation would be easy to achieve. Research of treatment of wastewater of food industries would be utilized by both big scale industries and small industries using addition of preservative substances. The type reactor of anaerobic process is anaerobic baffled reactor that will give better contact between wastewater and microorganism in the sludge. The variables conducted in this research are the baffled configuration, sludge height, preservative agent contents, hydralic retention time and influence of micro nutrients. The respons of this research are the COD effluent, remaining preservative agent, pH, formation of volatile fatty acid and total suspended solid. The result of this research is kinetic model of the anaerobic baffled reactor, reaction kinetic of preservative agent degradation and technology of treatment wastewater contains preservative agent. The benefit of this research is to solve the treatment of wastewater of food industries with preservative substance in order to achieve wastewater limit regulation and also to prevent the environmental deterioration.

Development of a flocculation sub-model for a 3-D CFD model based on rectangular settling tanks.

PubMed

Gong, M; Xanthos, S; Ramalingam, K; Fillos, J; Beckmann, K; Deur, A; McCorquodale, J A

2011-01-01

To assess performance and evaluate alternatives to improve the efficiency of rectangular Gould II type final settling tanks (FSTs), New York City Department of Environmental Protection and City College of NY developed a 3D computer model depicting the actual structural configuration of the tanks and the current and proposed hydraulic and solids loading rates. Fluent 6.3.26™ was the base platform for the computational fluid dynamics (CFD) model, for which sub-models of the SS settling characteristics, turbulence, flocculation and rheology were incorporated. This was supplemented by field and bench scale experiments to quantify the coefficients integral to the sub-models. The 3D model developed can be used to consider different baffle arrangements, sludge withdrawal mechanisms and loading alternatives to the FSTs. Flocculation in the front half of the rectangular tank especially in the region before and after the inlet baffle is one of the vital parameters that influences the capture efficiency of SS. Flocculation could be further improved by capturing medium and small size particles by creating an additional zone with an in-tank baffle. This was one of the methods that was adopted in optimizing the performance of the tank where the CCNY 3D CFD model was used to locate the in-tank baffle position. This paper describes the development of the flocculation sub-model and the relationship of the flocculation coefficients in the known Parker equation to the initial mixed liquor suspended solids (MLSS) concentration X0. A new modified equation is proposed removing the dependency of the breakup coefficient to the initial value of X0 based on preliminary data using normal and low concentration mixed liquor suspended solids values in flocculation experiments performed.

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 ...

7 CFR 993.106 - In-line inspection.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false In-line inspection. 993.106 Section 993.106 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE DRIED PRUNES PRODUCED IN...

7 CFR 993.504 - In-line inspection.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false In-line inspection. 993.504 Section 993.504 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE DRIED PRUNES PRODUCED IN...

7 CFR 993.106 - In-line inspection.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false In-line inspection. 993.106 Section 993.106 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE DRIED PRUNES PRODUCED IN...

7 CFR 993.106 - In-line inspection.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false In-line inspection. 993.106 Section 993.106 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE DRIED PRUNES PRODUCED IN...

Reduction of DOM fractions and their trihalomethane formation potential in surface river water by in-line coagulation with ceramic membrane filtration.

PubMed

Rakruam, Pharkphum; Wattanachira, Suraphong

2014-03-01

This research was aimed at investigating the reduction of DOM fractions and their trihalomethane formation potential (THMFP) by in-line coagulation with 0.1 μm ceramic membrane filtration. The combination of ceramic membrane filtration with a coagulation process is an alternative technology which can be applied to enhance conventional coagulation processes in the field of water treatment and drinking water production. The Ping River water (high turbidity water) was selected as the raw surface water because it is currently the main raw water source for water supply production in the urban and rural areas of Chiang Mai Province. From the investigation, the results showed that the highest percent reductions of DOC, UV-254, and THMFP (47.6%, 71.0%, and 67.4%, respectively) were achieved from in-line coagulation with ceramic membrane filtration at polyaluminum chloride dosage 40 mg/L. Resin adsorption techniques were employed to characterize the DOM in raw surface water and filtered water. The results showed that the use of a ceramic membrane with in-line coagulation was able to most efficiently reduce the hydrophobic fraction (HPOA) (68.5%), which was then followed by the hydrophilic fraction (HPIA) (49.3%). The greater mass DOC reduction of these two fractions provided the highest THMFP reductions (55.1% and 37.2%, respectively). Furthermore, the in-line coagulation with ceramic membrane filtration was able to reduce the hydrophobic (HPOB) fraction which is characterized by high reactivity toward THM formation. The percent reduction of mass DOC and THMFP of HPOB by in-line coagulation with ceramic membrane filtration was 45.9% and 48.0%, respectively. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Convective heat transfer from a pulsating radial jet reattachment (PRJR) nozzle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pak, J.Y.; James, D.L.; Parameswaran, S.

1999-07-01

Impinging jets of fluid have been used to cool, heat or dry surfaces in many industries including high temperature gas turbines, paper and glass manufacturing, textile drying, and electronic components. Jets may be broadly classified as either inline or radial. Inline jets typically have some type of circular or planer opening through which the fluid exits. The circular opening may be converging, well rounded, or of the same diameter as the nozzle or tube through which the fluid is delivered. Here, a numerical investigation for air exiting a Pulsating Radial Jet Reattachment (PRJR) nozzle was performed with various flow andmore » geometric conditions. The transient ensemble averaged Navier-Stokes equation with the standard {kappa}-{epsilon} turbulence model and the standard transient turbulent energy equation were solved to predict the velocity, pressure, and temperature distributions as a function of the pulsation rate, nondimensionalized nozzle-to-plate spacing, amplitude ratio, exit angle and gap Reynolds number. Sinusoidal profile, square and triangular pulsation profiles were simulated to determine the effect on the convective heat transfer during pulsation of nozzle. Grid movement is coupled to the flow field in a manner by a grid convection. Calculated reattachment radii for various conditions correlated well with previously obtained experimental results. Calculated convective heat transfer coefficients and surface pressure profiles for various geometric and flow conditions were compared with experimental results. Convective heat transfer coefficient calculations matched the experimental values very well outside the reattachment regions and underpredicted the convective heat transfer data underneath the nozzle in the dead water region and on the reattachment radius.« less

Investigate Fundamentals and Performance Improvements of Current In-Line Inspection Technologies for Mechanical Damage Detection

DOT National Transportation Integrated Search

2008-05-01

This Phase I report provides a comprehensive and in-depth review of the current status of in-line inspection technologies, including, but not limited to, Magnetic (Axial MFL, Circumferential MFL), Ultrasonic (UT), and Geometrical (Caliper) methods, i...

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Inline Measurement of Particle Concentrations in Multicomponent Suspensions using Ultrasonic Sensor and Least Squares Support Vector Machines.

PubMed

Zhan, Xiaobin; Jiang, Shulan; Yang, Yili; Liang, Jian; Shi, Tielin; Li, Xiwen

2015-09-18

This paper proposes an ultrasonic measurement system based on least squares support vector machines (LS-SVM) for inline measurement of particle concentrations in multicomponent suspensions. Firstly, the ultrasonic signals are analyzed and processed, and the optimal feature subset that contributes to the best model performance is selected based on the importance of features. Secondly, the LS-SVM model is tuned, trained and tested with different feature subsets to obtain the optimal model. In addition, a comparison is made between the partial least square (PLS) model and the LS-SVM model. Finally, the optimal LS-SVM model with the optimal feature subset is applied to inline measurement of particle concentrations in the mixing process. The results show that the proposed method is reliable and accurate for inline measuring the particle concentrations in multicomponent suspensions and the measurement accuracy is sufficiently high for industrial application. Furthermore, the proposed method is applicable to the modeling of the nonlinear system dynamically and provides a feasible way to monitor industrial processes.

Modeling of an 8-12 GHz receiver front-end based on an in-line MEMS frequency discriminator

NASA Astrophysics Data System (ADS)

Chu, Chenlei; Liao, Xiaoping

2018-06-01

This paper focuses on the modeling of an 8-12 GHz RF (radio frequency) receiver front-end based on an in-line MEMS (microelectromechanical systems) frequency discriminator. Actually, the frequency detection is realized by measuring the output dc thermal voltage generated by the MEMS thermoelectric power sensor. Based on this thermal voltage, it has a great potential to tune the resonant frequency of the VCO (voltage controlled oscillator) in the RF receiver front-end application. The equivalent circuit model of the in-line frequency discriminator is established and the measurement verification is also implemented. Measurement and simulation results show that the output dc thermal voltage has a nearly linear relation with frequency. A new construction of RF receiver front-end is then obtained by connecting the in-line frequency discriminator with the voltage controlling port of VCO. Lastly, a systemic simulation is processed by computer-aided software and the real-time simulation waveform at each key point is observed clearly.

Neural network Hilbert transform based filtered backprojection for fast inline x-ray inspection

NASA Astrophysics Data System (ADS)

Janssens, Eline; De Beenhouwer, Jan; Van Dael, Mattias; De Schryver, Thomas; Van Hoorebeke, Luc; Verboven, Pieter; Nicolai, Bart; Sijbers, Jan

2018-03-01

X-ray imaging is an important tool for quality control since it allows to inspect the interior of products in a non-destructive way. Conventional x-ray imaging, however, is slow and expensive. Inline x-ray inspection, on the other hand, can pave the way towards fast and individual quality control, provided that a sufficiently high throughput can be achieved at a minimal cost. To meet these criteria, an inline inspection acquisition geometry is proposed where the object moves and rotates on a conveyor belt while it passes a fixed source and detector. Moreover, for this acquisition geometry, a new neural-network-based reconstruction algorithm is introduced: the neural network Hilbert transform based filtered backprojection. The proposed algorithm is evaluated both on simulated and real inline x-ray data and has shown to generate high quality reconstructions of 400  ×  400 reconstruction pixels within 200 ms, thereby meeting the high throughput criteria.

Prediction of high frequency combustion instability in liquid propellant rocket engines

NASA Technical Reports Server (NTRS)

Kim, Y. M.; Chen, C. P.; Ziebarth, J. P.; Chen, Y. S.

1992-01-01

The present use of a numerical model developed for the prediction of high-frequency combustion stabilities in liquid propellant rocket engines focuses on (1) the overall behavior of nonlinear combustion instabilities (2) the effects of acoustic oscillations on the fuel-droplet vaporization and combustion process in stable and unstable engine operating conditions, oscillating flowfields, and liquid-fuel trajectories during combustion instability, and (3) the effects of such design parameters as inlet boundary conditions, initial spray conditions, and baffle length. The numerical model has yielded predictions of the tangential-mode combustion instability; baffle length and droplet size variations are noted to have significant effects on engine stability.

Control of Combustion-Instabilities Through Various Passive Devices

NASA Technical Reports Server (NTRS)

Frendi, Abdelkader; Nesman, Tom; Canabal, Francisco

2005-01-01

Results of a computational study on the effectiveness of various passive devices for the control of combustion instabilities are presented. An axi-symmetric combustion chamber is considered. The passive control devices investigated are, baffles, Helmholtz resonators and quarter-waves. The results show that a Helmholtz resonator with a smooth orifice achieves the best control results, while a baffle is the least effective for the frequency tested. At high sound pressure levels, the Helmholtz resonator is less effective. It is also found that for a quarter wave, the smoothness of the orifice has the opposite effect than the Helmholtz resonator, i.e. results in less control.

Bioconversion reactor

DOEpatents

McCarty, Perry L.; Bachmann, Andre

1992-01-01

A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor comprises a shell enclosing a predetermined volume, an inlet port through which a liquid stream containing organic materials enters the shell, and an outlet port through which the stream exits the shell. A series of vertical and spaced-apart baffles are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

Dynamic characteristic of a 30-cm mercury ion thruster

NASA Technical Reports Server (NTRS)

Serafini, J. S.; Mantenieks, M. A.; Rawlin, V. K.

1975-01-01

Measurements of the fluctuations of the discharge and beam plasmas of a 30 centimeter ion thruster were performed using 60 Hertz laboratory type power supplies. The time-varying properties of the discharge voltage and current, the ion beam current, and neutralizer keeper current were measured. The intensities of the fluctuations were found to depend on the beam and magnetic baffle currents. The shape of the frequency spectra of the discharge plasma fluctuations was found to be related to the beam and magnetic baffle currents. The measurements indicated that the discharge current fluctuations directly contribute to the beam current fluctuations and that the power supply characteristics modify these fluctuations.

Scale up of diesel oil biodegradation in a baffled roller bioreactor.

PubMed

Nikakhtari, Hossein; Song, Wanning; Kumar, Pardeep; Nemati, Mehdi; Hill, Gordon A

2010-05-01

Diesel oil is a suitable substance to represent petroleum contamination from accidental spills in operating and transportation facilities. Using a microbial culture enriched from a petroleum contaminated soil, biodegradation of diesel oil was carried out in 2.2, 55, and 220 L roller baffled bioreactors. The effects of bioreactor rotation speed (from 5 to 45 rpm) and liquid loading (from 18% to 73% of total volume) on the biodegradation of diesel oil were studied. In the small scale bioreactor (2.2L), the maximum rotation speed of 45 rpm resulted in the highest biodegradation rate with a first order biodegradation kinetic constant of 0.095 d(-1). In the larger scale bioreactors, rotation speed did not affect the biodegradation rate. Liquid loadings higher than 64% resulted in reduced biodegradation rates in the small scale bioreactor; however, in the larger roller bioreactors liquid loading did not affect the biodegradation rate. Biodegradation of diesel oil at 5 rpm and 73% loading is recommended for operating large scale roller baffled bioreactors. Under these conditions, high diesel oil concentrations up to 50 gL(-1) can be bioremediated at a rate of 1.61 gL(-1)d(-1). Copyright 2010 Elsevier Ltd. All rights reserved.

Construction and evaluation of an inexpensive weighing lysimeter for studying contaminant transport

NASA Astrophysics Data System (ADS)

Corwin, D. L.; LeMert, R. D.

1994-01-01

A description is provided of an above-ground, weighing lysimeter that minimizes the edge flow of water which can occur between the soil and the wall of the casing. The lysimeter was designed to study water flux and the movement of inorganic and/or organic pollutants as they pass through and beyond the root zone. The lysimeter is instrumented at selected depths with thermistors, soil solution extractors, time-domain reflectometry probes, gas extractors and tensiometers. These sensors provide temperature measurements, soil solution samples, water content measurements, soil atmosphere samples and water potential measurements. The horizontal insertion of these instruments from the side of the lysimeter reduces and channeling that might occur along the sides of the instruments, if they had been inserted vertically. Annular-ring baffles are located at selected depths to reduce edge flow between the lysimeter casing and the column of soil. The baffles redirect water flow away from the edge of the column. Data are presented that show a reduction in the hydraulic bypass of the lysimeter compared to a lysimeter without baffles. The total cost of a single lysimeter including materials and labor is under US $4000.

Patency of cavopulmonary connection studied by single phase electron beam computed tomography.

PubMed

Choi, Byoung Wook; Park, Young Hwan; Lee, Jong Kyun; Kim, Dong Joon; Kim, Min Jung; Choe, Kyu Ok

2003-10-01

The shunt patency and anatomic alteration of central PA after cavopulmonary connection was assessed by one phase electron-beam computed tomography (EBCT) METHODS: Thirteen patients that received a bi-directional cavo-pulmonary shunt (BCPS, n = 7) or total cavo-pulmonary connection (TCPC, n = 6) were included. The patency of the shunt and the anatomy of intra-pericardial PA were evaluated by EBCT, and compared by angiography and echocardiography. EBCT accurately evaluated shunt patency and the anatomy of the intra-pericardial PA, except for the incorrect diagnosis of SVC-PA shunt patency and peripheral pulmonary stenosis in two TCPC patients. Both of these patients had bilateral SVC and received either bilateral BCPS or ligation of the left SVC respectively. The baffle between the IVC and PA was partly opacified through a fenestration of the baffle, but was not opacified in two patients without fenestration. EBCT accurately evaluated shunt patency and the anatomy of central PA, however, the accuracy was limited in two cases with bilateral SVC. The opacification of the intra-atrial baffle was insufficient in TCPC cases. Multi-phase CT angiography may overcome this limitation in this patient subset.

A study on the applicability of in-line measurements in the monitoring of the pellet coating process.

PubMed

Hudovornik, Grega; Korasa, Klemen; Vrečer, Franc

2015-07-30

Special populations including paediatric and elderly patients often need advanced approaches in treatment, such as one-a-day dosing, which is achieved with modified release formulations or alternative routes of applications such as nasogastric route. Pellets are a dosage form that is frequently used in such formulations. The aim of the present work was to study the applicability of two in-line techniques, namely, Near Infrared Spectroscopy (NIR) and Spatial Filtering Technique (SFT) in the pellet coating process. The first objective of our work was to develop a prediction model for moisture content determination with the in-line NIR and to test its robustness in terms of sensitivity to changes in composition of the pellets and performance in wide range of moisture content. Secondly, the in-line SFT measurement was correlated with different off-line particle size methods. The third objective was to evaluate the ability of both in-line techniques for the detection of undesired deviations during the process, such as pellet attrition and agglomeration. Finally, the ability to predict coating thickness with the in-line NIR probe was evaluated. Results suggested that NIR prediction model for moisture content was less robust outside the calibration range and was also sensitive to changes in composition of the film coating. Nevertheless, satisfactory prediction was achieved in the case when coating composition was partially altered and adequate calibration range was used. The SFT probe results were in good correlation with off-line particle size measurement methods and proved to be an effective tool for coating thickness determination during the coating, however, the probe failed to accurately show the actual amount of the agglomerates formed during the process. In experiment when pellet attrition was initiated, both probes successfully detected abrasion of the pellet surface in real time. Furthermore, a predictive NIR model for coating thickness was made and showed a good potential to measure coating thickness in-line, suggesting that the NIR probe can be used as a single tool to monitor water content, coating thickness, and deviations in the coating process. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

Knowledge Gained from Practical Experience in the Designing of Aircraft Engines

NASA Technical Reports Server (NTRS)

Kurtz, Oskar

1933-01-01

The present report examines a few important points of engine design such as: in-line water cooled engines, air-cooled in-line engines, and air-cooled radial engines. Subassemblies are also discussed like cylinder types, blower driving gears, pistons, valves, bearings, and crankshafts.

7 CFR 993.106 - In-line inspection.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false In-line inspection. 993.106 Section 993.106 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... means inspection of prunes where samples are drawn from a flow of prunes prior to packaging. Effective...

7 CFR 993.504 - In-line inspection.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false In-line inspection. 993.504 Section 993.504 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... inspection of prunes where samples are drawn from a flow of prunes prior to packaging. Effective Date Note...

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)

Regularized reconstruction of absorbing and phase objects from a single in-line hologram, application to fluid mechanics and micro-biology.

PubMed

Jolivet, Frédéric; Momey, Fabien; Denis, Loïc; Méès, Loïc; Faure, Nicolas; Grosjean, Nathalie; Pinston, Frédéric; Marié, Jean-Louis; Fournier, Corinne

2018-04-02

Reconstruction of phase objects is a central problem in digital holography, whose various applications include microscopy, biomedical imaging, and fluid mechanics. Starting from a single in-line hologram, there is no direct way to recover the phase of the diffracted wave in the hologram plane. The reconstruction of absorbing and phase objects therefore requires the inversion of the non-linear hologram formation model. We propose a regularized reconstruction method that includes several physically-grounded constraints such as bounds on transmittance values, maximum/minimum phase, spatial smoothness or the absence of any object in parts of the field of view. To solve the non-convex and non-smooth optimization problem induced by our modeling, a variable splitting strategy is applied and the closed-form solution of the sub-problem (the so-called proximal operator) is derived. The resulting algorithm is efficient and is shown to lead to quantitative phase estimation on reconstructions of accurate simulations of in-line holograms based on the Mie theory. As our approach is adaptable to several in-line digital holography configurations, we present and discuss the promising results of reconstructions from experimental in-line holograms obtained in two different applications: the tracking of an evaporating droplet (size ∼ 100μm) and the microscopic imaging of bacteria (size ∼ 1μm).

In-line NIR spectroscopy for the understanding of polymer-drug interaction during pharmaceutical hot-melt extrusion.

PubMed

Saerens, Lien; Dierickx, Lien; Quinten, Thomas; Adriaensens, Peter; Carleer, Robert; Vervaet, Chris; Remon, Jean Paul; De Beer, Thomas

2012-05-01

The aim was to evaluate near-infrared spectroscopy for the in-line determination of the drug concentration, the polymer-drug solid-state behaviour and molecular interactions during hot-melt extrusion. Kollidon® SR was extruded with varying metoprolol tartrate (MPT) concentrations (20%, 30% and 40%) and monitored using NIR spectroscopy. A PLS model allowed drug concentration determination. The correlation between predicted and real MPT concentrations was good (R(2)=0.97). The predictive performance of the model was evaluated by the root mean square error of prediction, which was 1.54%. Kollidon® SR with 40% MPT was extruded at 105°C and 135°C to evaluate NIR spectroscopy for in-line polymer-drug solid-state characterisation. NIR spectra indicated the presence of amorphous MPT and hydrogen bonds between drug and polymer in the extrudates. More amorphous MPT and interactions could be found in the extrudates produced at 135°C than at 105°C. Raman spectroscopy, DSC and ATR FT-IR were used to confirm the NIR observations. Due to the instability of the formulation, only in-line Raman spectroscopy was an adequate confirmation tool. NIR spectroscopy is a potential PAT-tool for the in-line determination of API concentration and for the polymer-drug solid-state behaviour monitoring during pharmaceutical hot-melt extrusion. Copyright © 2012 Elsevier B.V. All rights reserved.

40 CFR 98.80 - Definition of the source category.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Cement Production § 98.80 Definition of the source category. The cement production source category consists of each kiln and each in-line kiln/raw mill at any portland cement manufacturing facility including alkali bypasses, and includes kilns and in-line kiln/raw...

40 CFR 98.80 - Definition of the source category.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Cement Production § 98.80 Definition of the source category. The cement production source category consists of each kiln and each in-line kiln/raw mill at any portland cement manufacturing facility including alkali bypasses, and includes kilns and in-line kiln/raw...

40 CFR 98.80 - Definition of the source category.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Cement Production § 98.80 Definition of the source category. The cement production source category consists of each kiln and each in-line kiln/raw mill at any portland cement manufacturing facility including alkali bypasses, and includes kilns and in-line kiln/raw...

40 CFR 63.1341 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... other materials to form cement. Clinker cooler means equipment into which clinker product leaving the... kiln or coal mills using exhaust gases from the clinker cooler are not an in-line coal mill. In-line kiln/raw mill means a system in a portland cement production process where a dry kiln system is...

40 CFR 63.1341 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... other materials to form cement. Clinker cooler means equipment into which clinker product leaving the... kiln or coal mills using exhaust gases from the clinker cooler are not an in-line coal mill. In-line kiln/raw mill means a system in a portland cement production process where a dry kiln system is...

REMOVAL OF CRYPTOSPORIDIUM BY IN-LINE FILTRATION AS A FUNCTION OF OOCYST AGE AND PRESERVATION METHOD

EPA Science Inventory

This study examined the impacts of oocyst preservation method and age on the removal of seeded Cryptosporidium oocysts by in-line filtration. An existing study has investigated the infectivity of Cryptosporidium parvum as a function of preservation method and oocyst age. Simila...

REMOVAL OF CRYPTOSPORIDIUM BY IN-LINE FILTRATION AS A FUNCTION OF OOCYST AGE AND PRESERVATION METHOD

EPA Science Inventory

This study examined the impacts of oocyst preservation method and age on the removal of seeded Cryptosporidium oocysts by in-line filtration. An existing study has investigated the infectivity of Cryptosporidium Parvum as a function of preservation method and oocyst age. Simila...

40 CFR 86.1316-94 - Calibrations; frequency and overview.

Code of Federal Regulations, 2012 CFR

2012-07-01

... through 86.1324. (2) Calibrate the engine dynamometer flywheel torque and speed measurement transducers... torque feedback signal at steady-state conditions by comparing: (i) Shaft torque feedback to dynamometer beam load; or (ii) By comparing in-line torque to armature current; or (iii) By checking the in-line...

40 CFR 86.1316-94 - Calibrations; frequency and overview.

Code of Federal Regulations, 2011 CFR

2011-07-01

... through 86.1324. (2) Calibrate the engine dynamometer flywheel torque and speed measurement transducers... torque feedback signal at steady-state conditions by comparing: (i) Shaft torque feedback to dynamometer beam load; or (ii) By comparing in-line torque to armature current; or (iii) By checking the in-line...

40 CFR 86.1316-94 - Calibrations; frequency and overview.

Code of Federal Regulations, 2010 CFR

2010-07-01

... through 86.1324. (2) Calibrate the engine dynamometer flywheel torque and speed measurement transducers... torque feedback signal at steady-state conditions by comparing: (i) Shaft torque feedback to dynamometer beam load; or (ii) By comparing in-line torque to armature current; or (iii) By checking the in-line...

40 CFR 86.1316-94 - Calibrations; frequency and overview.

Code of Federal Regulations, 2013 CFR

2013-07-01

... through 86.1324. (2) Calibrate the engine dynamometer flywheel torque and speed measurement transducers... torque feedback signal at steady-state conditions by comparing: (i) Shaft torque feedback to dynamometer beam load; or (ii) By comparing in-line torque to armature current; or (iii) By checking the in-line...

Modelling of sedimentation and remobilization in in-line storage sewers for stormwater treatment.

PubMed

Frehmann, T; Flores, C; Luekewille, F; Mietzel, T; Spengler, B; Geiger, W F

2005-01-01

A special arrangement of combined sewer overflow tanks is the in-line storage sewer with downstream discharge (ISS-down). This layout has the advantage that, besides the sewer system, no other structures are required for stormwater treatment. The verification of the efficiency with respect to the processes of sedimentation and remobilization of sediment within the in-line storage sewer with downstream discharge is carried out in a combination of a field and a pilot plant study. The model study was carried out using a pilot plant model scaled 1:13. The following is intended to present some results of the pilot plant study and the mathematical empirical modelling of the sedimentation and remobilization process.

Acoustofluidic bacteria separation

NASA Astrophysics Data System (ADS)

Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun

2017-01-01

Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

Effect of baffle on slosh reaction forces in rotating liquid helium subjected to a lateral impulse in microgravity

NASA Technical Reports Server (NTRS)

Hung, R. J.; Long, Y. T.

1995-01-01

Sloshing dynamics within a partially filled rotating Dewar of superfluid He II are investigated in response to a lateral impulse. The study investigates several factors, including how the rotating bubble of superfluid He II reacts to the impulse in microgravity, how the amplitudes of slosh reaction forces act on the Dewar with various rotating speeds, how the frequencies of the sloshing modes excited differ in terms of differences in rotating speeds, and how the sloshing dynamics differ with and without a baffle. The numerical computation of sloshing dynamics is based on the noninertial frame spacecraft-bound coordinates. Results of the simulations are illustrated.

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 the...

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 the...

A non-iterative twin image elimination method with two in-line digital holograms

NASA Astrophysics Data System (ADS)

Kim, Jongwu; Lee, Heejung; Jeon, Philjun; Kim, Dug Young

2018-02-01

We propose a simple non-iterative in-line holographic measurement method which can effectively eliminate a twin image in digital holographic 3D imaging. It is shown that a twin image can be effectively eliminated with only two measured holograms by using a simple numerical propagation algorithm and arithmetic calculations.

LEAD LEACHING FROM IN-LINE BRASS DEVICES: A CRITICAL EVALUATION OF THE EXISTING STANDARD

EPA Science Inventory

The ANSI/NSF 61, Section 8 standard is intended to protect the public from in-line brass plumbing products that might leach excessive levels of lead to potable water. Experiments were conducted to examine the practical rigor of this test. Contrary to expectations, the test was no...

Generalized Poisson-Kac Processes: Basic Properties and Implications in Extended Thermodynamics and Transport

NASA Astrophysics Data System (ADS)

Giona, Massimiliano; Brasiello, Antonio; Crescitelli, Silvestro

2016-04-01

We introduce a new class of stochastic processes in Rn,{{{mathbb R}}^n}, referred to as generalized Poisson-Kac (GPK) processes, that generalizes the Poisson-Kac telegrapher's random motion in higher dimensions. These stochastic processes possess finite propagation velocity, almost everywhere smooth trajectories, and converge in the Kac limit to Brownian motion. GPK processes are defined by coupling the selection of a bounded velocity vector from a family of N distinct ones with a Markovian dynamics controlling probabilistically this selection. This model can be used as a probabilistic tool for a stochastically consistent formulation of extended thermodynamic theories far from equilibrium.

Automated in-line gel filtration for native state mass spectrometry.

PubMed

Waitt, Greg M; Xu, Robert; Wisely, G Bruce; Williams, Jon D

2008-02-01

Characterization of protein-ligand complexes by nondenaturing mass spectrometry provides direct evidence of drug-like molecules binding with potential therapeutic targets. Typically, protein-ligand complexes to be analyzed contain buffer salts, detergents, and other additives to enhance protein solubility, all of which make the sample unable to be analyzed directly by electrospray ionization mass spectrometry. This work describes an in-line gel-filtration method that has been automated and optimized. Automation was achieved using commercial HPLC equipment. Gel column parameters that were optimized include: column dimensions, flow rate, packing material type, particle size, and molecular weight cut-off. Under optimal conditions, desalted protein ions are detected 4 min after injection and the analysis is completed in 20 min. The gel column retains good performance even after >200 injections. A demonstration for using the in-line gel-filtration system is shown for monitoring the exchange of fatty acids from the pocket of a nuclear hormone receptor, peroxisome proliferator activator-delta (PPARdelta) with a tool compound. Additional utilities of in-line gel-filtration mass spectrometry system will also be discussed.

The in-line measurement of plant cell biomass using radio frequency impedance spectroscopy as a component of process analytical technology.

PubMed

Holland, Tanja; Blessing, Daniel; Hellwig, Stephan; Sack, Markus

2013-10-01

Radio frequency impedance spectroscopy (RFIS) is a robust method for the determination of cell biomass during fermentation. RFIS allows non-invasive in-line monitoring of the passive electrical properties of cells in suspension and can distinguish between living and dead cells based on their distinct behavior in an applied radio frequency field. We used continuous in situ RFIS to monitor batch-cultivated plant suspension cell cultures in stirred-tank bioreactors and compared the in-line data to conventional off-line measurements. RFIS-based analysis was more rapid and more accurate than conventional biomass determination, and was sensitive to changes in cell viability. The higher resolution of the in-line measurement revealed subtle changes in cell growth which were not accessible using conventional methods. Thus, RFIS is well suited for correlating such changes with intracellular states and product accumulation, providing unique opportunities for employing systems biotechnology and process analytical technology approaches to increase product yield and quality. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of a SEM-based low-energy in-line electron holography microscope for individual particle imaging.

PubMed

Adaniya, Hidehito; Cheung, Martin; Cassidy, Cathal; Yamashita, Masao; Shintake, Tsumoru

2018-05-01

A new SEM-based in-line electron holography microscope has been under development. The microscope utilizes conventional SEM and BF-STEM functionality to allow for rapid searching of the specimen of interest, seamless interchange between SEM, BF-STEM and holographic imaging modes, and makes use of coherent low-energy in-line electron holography to obtain low-dose, high-contrast images of light element materials. We report here an overview of the instrumentation and first experimental results on gold nano-particles and carbon nano-fibers for system performance tests. Reconstructed images obtained from the holographic imaging mode of the new microscope show substantial image contrast and resolution compared to those acquired by SEM and BF-STEM modes, demonstrating the feasibility of high-contrast imaging via low-energy in-line electron holography. The prospect of utilizing the new microscope to image purified biological specimens at the individual particle level is discussed and electron optical issues and challenges to further improve resolution and contrast are considered. Copyright © 2018 Elsevier B.V. All rights reserved.

Geometry-constraint-scan imaging for in-line phase contrast micro-CT.

PubMed

Fu, Jian; Yu, Guangyuan; Fan, Dekai

2014-01-01

X-ray phase contrast computed tomography (CT) uses the phase shift that x-rays undergo when passing through matter, rather than their attenuation, as the imaging signal and may provide better image quality in soft-tissue and biomedical materials with low atomic number. Here a geometry-constraint-scan imaging technique for in-line phase contrast micro-CT is reported. It consists of two circular-trajectory scans with x-ray detector at different positions, the phase projection extraction method with the Fresnel free-propagation theory and the filter back-projection reconstruction algorithm. This method removes the contact-detector scan and the pure phase object assumption in classical in-line phase contrast Micro-CT. Consequently it relaxes the experimental conditions and improves the image contrast. This work comprises a numerical study of this technique and its experimental verification using a biomedical composite dataset measured at an x-ray tube source Micro-CT setup. The numerical and experimental results demonstrate the validity of the presented method. It will be of interest for a wide range of in-line phase contrast Micro-CT applications in biology and medicine.

Effect of extraction method on the concentrations of selected bioactive compounds in mandarin juice.

PubMed

Nogata, Yoichi; Ohta, Hideaki; Sumida, Takashi; Sekiya, Keizo

2003-12-03

A mandarin-type citrus fruit, ponkan (Citrus reticulata), was processed by in-line, chopper pulper, and hand-press extractions to investigate the effect of extraction method on the concentrations of bioactive compounds in processed juice. Concentrations of polymethoxylated flavones (tangeretin, nobiletin, and sinensetin) and beta-cryptoxanthin in juice, and inhibitory activities against arachidonate cyclooxygenase and lipoxygenases of the juice extract were analyzed. The juice processed by hand-press extraction contained the largest amounts of nobiletin (3.56 mg/100 mL), tangeretin (4.10 mg/100 mL), and sinensetin (0.13 mg/100 mL). Concentrations of beta-cryptoxanthin were 0.66, 0.59, 0.55, and 0.50 mg/100 mL in chopper pulper, in-line (5/64 in.), in-line (8/64 in.) and hand-press juices, respectively. Both extracts of in-line juices showed greater inhibitory activity toward platelet 12-lipoxygenase than the others. The inhibitory effect of hand-press juice extract on platelet cyclooxygenase activity was remarkable among juice extracts. All juice extracts effectively inhibited polymorphonuclear 5-lipoxygenase activity at nearly the same rate.

Reflectance infrared spectroscopy for in-line monitoring of nicotine during a coating process for an oral thin film.

PubMed

Hammes, Florian; Hille, Thomas; Kissel, Thomas

2014-02-01

A process analytical method using reflectance infrared spectrometry was developed for the in-line monitoring of the amount of the active pharmaceutical ingredient (API) nicotine during a coating process for an oral thin film (OTF). In-line measurements were made using a reflectance infrared (RI) sensor positioned after the last drying zone of the coating line. Real-time spectra from the coating process were used for modelling the nicotine content. Partial least squares (PLS1) calibration models with different data pre-treatments were generated. The calibration model with the most comparable standard error of calibration (SEC) and the standard error of cross validation (SECV) was selected for an external validation run on the production coating line with an independent laminate. Good correlations could be obtained between values estimated from the reflectance infrared data and the reference HPLC test method, respectively. With in-line measurements it was possible to allow real-time adjustments during the production process to keep product specifications within predefined limits hence avoiding loss of material and batch. Copyright © 2013 Elsevier B.V. All rights reserved.

Validation of the Sensewear Armband during recreational in-line skating.

PubMed

Soric, Maroje; Mikulic, Pavle; Misigoj-Durakovic, Marjeta; Ruzic, Lana; Markovic, Goran

2012-03-01

Multi-sensor body monitors that combine accelerometry with other physiological data are designed to overcome drawbacks of accelerometers in assessing activities with little or no vertical movement. One of such devices is the Sensewear Armband (SWA) which has been extensively validated during various activities. However, very few of the validation studies included activities other than walking and running. The aim of this investigation was to assess the validity of the SWA during recreational in-line skating. Nineteen participants (11 females and 8 males), 28 (±6) years of age, performed in-line skating exercise on a circular track at a self-selected pace. Energy expenditure was measured with the SWA and the Cosmed K4b(2) breath-by-breath portable metabolic unit. The mean (SD) energy expenditure during in-line skating estimated by the SWA [25.5 (5.8) kJ/min] was significantly lower compared with indirect calorimetry [44.2 (9.7) kJ/min, P < 0.001]. Similarly, the mean (SD) MET values recorded by the SWA were also lower compared with IC [5.3 (1.0) METs vs. 9.1 (1.6) METs, P < 0.001]. The ratio limits of agreement suggest that in 95% of cases the SWA will underestimate the energy expenditure and MET values during in-line skating by as much as 24-56% compared with indirect calorimetry. In conclusion, the results of the present study indicate that the SWA is not able to overcome the drawbacks of accelerometry in assessing activities with limited vertical movement.

Automated in-line mixing system for large scale production of chitosan-based polyplexes.

PubMed

Tavakoli Naeini, Ashkan; Soliman, Ousamah Younoss; Alameh, Mohamad Gabriel; Lavertu, Marc; Buschmann, Michael D

2017-08-15

Chitosan (CS)-based polyplexes are efficient non-viral gene delivery systems that are most commonly prepared by manual mixing. However, manual mixing is not only poorly controlled but also restricted to relatively small preparation volumes, limiting clinical applications. In order to overcome these drawbacks and to produce clinical quantities of CS-based polyplexes, a fully automated in-line mixing platform was developed for production of large batches of small-size and homogeneous CS-based polyplexes. Operational conditions to produce small-sized homogeneous polyplexes were identified. Increasing mixing concentrations of CS and nucleic acid was directly associated with an increase in size and polydispersity of both CS/pDNA and CS/siRNA polyplexes. We also found that although the speed of mixing has a negligible impact on the properties of CS/pDNA polyplexes, the size and polydispersity of CS/siRNA polyplexes are strongly influenced by the mixing speed: the higher the speed, the smaller the size and polydispersity. While in-line and manual CS/pDNA polyplexes had similar size and PDI, CS/siRNA polyplexes were smaller and more homogenous when prepared in-line in the non-laminar flow regime compared to manual method. Finally, we found that in-line mixed CS/siRNA polyplexes have equivalent or higher silencing efficiency of ApoB in HepG2 cells, compared to manually prepared polyplexes. Copyright © 2017 Elsevier Inc. All rights reserved.

Quantitative investigation of the edge enhancement in in-line phase contrast projections and tomosynthesis provided by distributing microbubbles on the interface between two tissues: a phantom study

NASA Astrophysics Data System (ADS)

Wu, Di; Donovan Wong, Molly; Li, Yuhua; Fajardo, Laurie; Zheng, Bin; Wu, Xizeng; Liu, Hong

2017-12-01

The objective of this study was to quantitatively investigate the ability to distribute microbubbles along the interface between two tissues, in an effort to improve the edge and/or boundary features in phase contrast imaging. The experiments were conducted by employing a custom designed tissue simulating phantom, which also simulated a clinical condition where the ligand-targeted microbubbles are self-aggregated on the endothelium of blood vessels surrounding malignant cells. Four different concentrations of microbubble suspensions were injected into the phantom: 0%, 0.1%, 0.2%, and 0.4%. A time delay of 5 min was implemented before image acquisition to allow the microbubbles to become distributed at the interface between the acrylic and the cavity simulating a blood vessel segment. For comparison purposes, images were acquired using three system configurations for both projection and tomosynthesis imaging with a fixed radiation dose delivery: conventional low-energy contact mode, low-energy in-line phase contrast and high-energy in-line phase contrast. The resultant images illustrate the edge feature enhancements in the in-line phase contrast imaging mode when the microbubble concentration is extremely low. The quantitative edge-enhancement-to-noise ratio calculations not only agree with the direct image observations, but also indicate that the edge feature enhancement can be improved by increasing the microbubble concentration. In addition, high-energy in-line phase contrast imaging provided better performance in detecting low-concentration microbubble distributions.

Enhancing patient understanding of medical procedures: evaluation of an interactive multimedia program with in-line exercises.

PubMed

Tait, Alan R; Voepel-Lewis, Terri; Chetcuti, Stanley J; Brennan-Martinez, Colleen; Levine, Robert

2014-05-01

Standard print and verbal information provided to patients undergoing treatments are 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. 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. 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% to 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. 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. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Resistance Distances and Kirchhoff Index in Generalised Join Graphs

NASA Astrophysics Data System (ADS)

Chen, Haiyan

2017-03-01

The resistance distance between any two vertices of a connected graph is defined as the effective resistance between them in the electrical network constructed from the graph by replacing each edge with a unit resistor. The Kirchhoff index of a graph is defined as the sum of all the resistance distances between any pair of vertices of the graph. Let G=H[G1, G2, …, Gk ] be the generalised join graph of G1, G2, …, Gk determined by H. In this paper, we first give formulae for resistance distances and Kirchhoff index of G in terms of parameters of G'is {G'_i}s and H. Then, we show that computing resistance distances and Kirchhoff index of G can be decomposed into simpler ones. Finally, we obtain explicit formulae for resistance distances and Kirchhoff index of G when G'is {G'_i}s and H take some special graphs, such as the complete graph, the path, and the cycle.

TH-AB-BRA-12: Experimental Results From the First High-Field Inline MRI-Linac

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keall, P; Dong, B; Zhang, K

Purpose: The pursuit of real-time image guided radiotherapy using optimal tissue contrast has seen the development of several hybrid MRI-treatment systems, high field and low field, and inline and perpendicular configurations. As part of a new MRI-Linac program, an MRI scanner was integrated with a linear accelerator to enable investigations of a coupled inline MRI-Linac system. This work describes our experimental results from the first high-field inline MRI-Linac. Methods: A 1.5 Tesla magnet (Sonata, Siemens) was located in a purpose built RF cage enabling shielding from and close proximity to a linear accelerator with inline orientation. A portable linear acceleratormore » (Linatron, Varian) was installed together with a multi-leaf collimator (Millennium, Varian) to provide dynamic field collimation and the whole assembly built onto a stainless-steel rail system. A series of MRI-Linac experiments was performed to investigate: (1) image quality with beam on measured using a macropodine (kangaroo) ex vivo phantom; (2) the noise as a function of beam state measured using a 6-channel surface coil array and; (3) electron focusing measured using GafChromic film. Results: (1) The macropodine phantom image quality with the beam on was almost identical to that with the beam off. (2) Noise measured with a surface RF coil produced a 25% elevation of background noise when the radiation beam was on. (3) Film measurements demonstrated electron focusing occurring at the center of the radiation field. Conclusion: The first high-field MRI-Linac has been built and experimentally characterized. This system has allowed us to establish the efficacy of a high field in-line MRI-Linac and study a number of the technical challenges and solutions. Supported by the Australian National Health and Medical Research Council, the Australian Research Council, the Australian Cancer Research Foundation and the Health and Hospitals Fund.« less

Technical Note: Experimental results from a prototype high-field inline MRI-linac

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liney, G. P., E-mail: gary.liney@sswahs.nsw.gov.au

Purpose: The pursuit of real-time image guided radiotherapy using optimal tissue contrast has seen the development of several hybrid magnetic resonance imaging (MRI)-treatment systems, high field and low field, and inline and perpendicular configurations. As part of a new MRI-linac program, an MRI scanner was integrated with a linear accelerator to enable investigations of a coupled inline MRI-linac system. This work describes results from a prototype experimental system to demonstrate the feasibility of a high field inline MR-linac. Methods: The magnet is a 1.5 T MRI system (Sonata, Siemens Healthcare) was located in a purpose built radiofrequency (RF) cage enablingmore » shielding from and close proximity to a linear accelerator with inline (and future perpendicular) orientation. A portable linear accelerator (Linatron, Varian) was installed together with a multileaf collimator (Millennium, Varian) to provide dynamic field collimation and the whole assembly built onto a stainless-steel rail system. A series of MRI-linac experiments was performed to investigate (1) image quality with beam on measured using a macropodine (kangaroo) ex vivo phantom; (2) the noise as a function of beam state measured using a 6-channel surface coil array; and (3) electron contamination effects measured using Gafchromic film and an electronic portal imaging device (EPID). Results: (1) Image quality was unaffected by the radiation beam with the macropodine phantom image with the beam on being almost identical to the image with the beam off. (2) Noise measured with a surface RF coil produced a 25% elevation of background intensity when the radiation beam was on. (3) Film and EPID measurements demonstrated electron focusing occurring along the centerline of the magnet axis. Conclusions: A proof-of-concept high-field MRI-linac has been built and experimentally characterized. This system has allowed us to establish the efficacy of a high field inline MRI-linac and study a number of the technical challenges and solutions.« less

In-line UV spectroscopy for the quantification of low-dose active ingredients during the manufacturing of pharmaceutical semi-solid and liquid formulations.

PubMed

Bostijn, N; Hellings, M; Van Der Veen, M; Vervaet, C; De Beer, T

2018-07-12

UltraViolet (UV) spectroscopy was evaluated as an innovative Process Analytical Technology (PAT) - tool for the in-line and real-time quantitative determination of low-dosed active pharmaceutical ingredients (APIs) in a semi-solid (gel) and a liquid (suspension) pharmaceutical formulation during their batch production process. The performance of this new PAT-tool (i.e., UV spectroscopy) was compared with an already more established PAT-method based on Raman spectroscopy. In-line UV measurements were carried out with an immersion probe while for the Raman measurements a non-contact PhAT probe was used. For both studied formulations, an in-line API quantification model was developed and validated per spectroscopic technique. The known API concentrations (Y) were correlated with the corresponding in-line collected preprocessed spectra (X) through a Partial Least Squares (PLS) regression. Each developed quantification method was validated by calculating the accuracy profile on the basis of the validation experiments. Furthermore, the measurement uncertainty was determined based on the data generated for the determination of the accuracy profiles. From the accuracy profile of the UV- and Raman-based quantification method for the gel, it was concluded that at the target API concentration of 2% (w/w), 95 out of 100 future routine measurements given by the Raman method will not deviate more than 10% (relative error) from the true API concentration, whereas for the UV method the acceptance limits of 10% were exceeded. For the liquid formulation, the Raman method was not able to quantify the API in the low-dosed suspension (0.09% (w/w) API). In contrast, the in-line UV method was able to adequately quantify the API in the suspension. This study demonstrated that UV spectroscopy can be adopted as a novel in-line PAT-technique for low-dose quantification purposes in pharmaceutical processes. Important is that none of the two spectroscopic techniques was superior to the other for both formulations: the Raman method was more accurate in quantifying the API in the gel (2% (w/w) API), while the UV method performed better for API quantification in the suspension (0.09% (w/w) API). Copyright © 2018 Elsevier B.V. All rights reserved.

Reliability and Validity of the Inline Skating Skill Test

PubMed Central

Radman, Ivan; Ruzic, Lana; Padovan, Viktoria; Cigrovski, Vjekoslav; Podnar, Hrvoje

2016-01-01

This study aimed to examine the reliability and validity of the inline skating skill test. Based on previous skating experience forty-two skaters (26 female and 16 male) were randomized into two groups (competitive level vs. recreational level). They performed the test four times, with a recovery time of 45 minutes between sessions. Prior to testing, the participants rated their skating skill using a scale from 1 to 10. The protocol included performance time measurement through a course, combining different skating techniques. Trivial changes in performance time between the repeated sessions were determined in both competitive females/males and recreational females/males (-1.7% [95% CI: -5.8–2.6%] – 2.2% [95% CI: 0.0–4.5%]). In all four subgroups, the skill test had a low mean within-individual variation (1.6% [95% CI: 1.2–2.4%] – 2.7% [95% CI: 2.1–4.0%]) and high mean inter-session correlation (ICC = 0.97 [95% CI: 0.92–0.99] – 0.99 [95% CI: 0.98–1.00]). The comparison of detected typical errors and smallest worthwhile changes (calculated as standard deviations × 0.2) revealed that the skill test was able to track changes in skaters’ performances. Competitive-level skaters needed shorter time (24.4–26.4%, all p < 0.01) to complete the test in comparison to recreational-level skaters. Moreover, moderate correlation (ρ = 0.80–0.82; all p < 0.01) was observed between the participant’s self-rating and achieved performance times. In conclusion, the proposed test is a reliable and valid method to evaluate inline skating skills in amateur competitive and recreational level skaters. Further studies are needed to evaluate the reproducibility of this skill test in different populations including elite inline skaters. Key points Study evaluated the reliability and construct validity of a newly developed inline skating skill test. Evaluated test is a first protocol designed to assess specific inline skating skill. Two groups of amateur skaters with different skating proficiency repeated the skill test in four separate occasions. The results suggest that evaluated test is reliable and valid to evaluate inline skating skill in amateur skaters. PMID:27803616

Signatures of Higgs dilaton and critical Higgs inflation

NASA Astrophysics Data System (ADS)

García-Bellido, Juan

2018-01-01

We test the Higgs dilaton inflation model (HDM) using the latest cosmological datasets, including the cosmic microwave background temperature, polarization and lensing data from the Planck satellite (2015), the BICEP and Keck Array experiments, the type Ia supernovae from the JLA catalogue, the baryon acoustic oscillations from CMASS, LOWZ and 6dF, the weak lensing data from the CFHTLenS survey and the matter power spectrum measurements from the latest SDSS data release. We find that the values of all cosmological parameters allowed by the HDM are well within the Planck satellite (2015) constraints. In particular, we determine , , , and (at 95.5% c.l.). We also place new stringent constraints on the couplings of the HDM, ξχ<0.00328 and (at 95.5% c.l.). We find that the HDM is only slightly better than the w0waCDM model, with . Given that the HDM has two fewer parameters, we find Bayesian evidence favouring the HDM over the w0waCDM model. We also study the critical Higgs inflation model, taking into account the running of both the self-coupling λ(μ) and the non-minimal coupling to gravity ξ(μ). We find peaks in the curvature power spectrum at scales corresponding to the critical value μ that re-enter during the radiation era and collapse to form a broad distribution of clustered primordial black holes, which could constitute today the main component of dark matter. This article is part of the Theo Murphy meeting issue `Higgs cosmology'.

Removal of Fecal Indicators, Pathogenic Bacteria, Adenovirus, Cryptosporidium and Giardia (oo)cysts in Waste Stabilization Ponds in Northern and Eastern Australia

PubMed Central

Sheludchenko, Maxim; Padovan, Anna; Katouli, Mohammad; Stratton, Helen

2016-01-01

Maturation ponds are used in rural and regional areas in Australia to remove the microbial loads of sewage wastewater, however, they have not been studied intensively until present. Using a combination of culture-based methods and quantitative real-time PCR, we assessed microbial removal rates in maturation ponds at four waste stabilization ponds (WSP) with (n = 1) and without (n = 3) baffles in rural and remote communities in Australia. Concentrations of total coliforms, E. coli, enterococci, Campylobacter spp., Salmonella spp., F+ RNA coliphage, adenovirus, Cryptosporidium spp. and Giardia (oo) cysts in maturation ponds were measured at the inlet and outlet. Only the baffled pond demonstrated a significant removal of most of the pathogens tested and therefore was subjected to further study by analyzing E. coli and enterococci concentrations at six points along the baffles over five sampling rounds. Using culture-based methods, we found a decrease in the number of E. coli and enterococci from the initial values of 100,000 CFU per 100 mL in the inlet samples to approximately 1000 CFU per 100 mL in the outlet samples for both bacterial groups. Giardia cysts removal was relatively higher than fecal indicators reduction possibly due to sedimentation. PMID:26729150

Design of a dynamic sonar emitter inspired by hipposiderid bats.

PubMed

Yang, Luhui; Yu, Allison; Mueller, Rolf

2018-06-19

The ultrasonic emission in the biosonar systems of bats such as the Old World leaf-nosed bats (family Hipposideridae) and the related horseshoe bats (family Rhinolophidae) is characterized by a unique dynamics where baffle shapes ("noseleaves") deform while diffracting the outgoing wave packets. As of now, nothing comparable to this dynamics has been used in any related engineering application (e.g., sonar or radar). Prior work with simple concave baffle shapes has demonstrated an impact of the dynamics on the emission characteristics, but it has remained unclear if this was simply due to the change in aperture size or also influenced by geometrical shape detail. Hence, it has also remained unclear if the time-variant effects reported so far could be further enhanced through different static and dynamic geometries. To address this issue, we have created a dynamic emission baffle with biomimetic shape detail modeled after Pratt's roundleaf bats (\\textit{Hipposideros pratti}). The impact of this shape's dynamic deformation on the time-variant emission characteristics was evaluated by virtue of the gradient magnitude and the entropy in the gradient orientation. The results have shown that the dynamics resulted in much larger gradients in a signal representation that changed jointly over direction and time. © 2018 IOP Publishing Ltd.

Removal of Fecal Indicators, Pathogenic Bacteria, Adenovirus, Cryptosporidium and Giardia (oo)cysts in Waste Stabilization Ponds in Northern and Eastern Australia.

PubMed

Sheludchenko, Maxim; Padovan, Anna; Katouli, Mohammad; Stratton, Helen

2016-01-02

Maturation ponds are used in rural and regional areas in Australia to remove the microbial loads of sewage wastewater, however, they have not been studied intensively until present. Using a combination of culture-based methods and quantitative real-time PCR, we assessed microbial removal rates in maturation ponds at four waste stabilization ponds (WSP) with (n = 1) and without (n = 3) baffles in rural and remote communities in Australia. Concentrations of total coliforms, E. coli, enterococci, Campylobacter spp., Salmonella spp., F+ RNA coliphage, adenovirus, Cryptosporidium spp. and Giardia (oo) cysts in maturation ponds were measured at the inlet and outlet. Only the baffled pond demonstrated a significant removal of most of the pathogens tested and therefore was subjected to further study by analyzing E. coli and enterococci concentrations at six points along the baffles over five sampling rounds. Using culture-based methods, we found a decrease in the number of E. coli and enterococci from the initial values of 100,000 CFU per 100 mL in the inlet samples to approximately 1000 CFU per 100 mL in the outlet samples for both bacterial groups. Giardia cysts removal was relatively higher than fecal indicators reduction possibly due to sedimentation.

Increasing Helicity to Achieve a Dynamo State on the Three-Meter Model of the Earth's Core

NASA Astrophysics Data System (ADS)

Rojas, R.; Perevalov, A.; Lathrop, D. P.

2017-12-01

Dynamo theory describes the generation of magnetic fields in the flows of conducting fluids, for example, in stars and planetary cores. Spherical Couette flows, which are flows between two concentric and independently rotating spheres, is one of the experimental models for achieving this task in the laboratory. We have performed dynamo state search in our three-meter spherical-Couette model reaching up to Reynolds number near 108 with amplifications of the field between 10-30% but without a self-sustained dynamo magnetic field. A recent numerical work [K. Finke and A. Tilgner. Phys. Rev. E, 86:016310, Jul 2012] suggested that a roughened inner core reduces the threshold for dynamo action. The mean flow would have more poloidal component than the one we are generating with our current smooth sphere setup. With baffles flow would be expelled radially outward on the equatorial plane and returned at the poles, with opposite helicities in the two hemispheres. Baffles welded on our smooth inner sphere are proposed to achieve this task. We are working to perform experiments on a scaled water model of our experimental setup with Reynolds number near 105 to measure the helicity improvements of different baffle designs in support of upcoming Three-Meter modifications. We gratefully acknowledge support from NSF EAR-1417148.

A design for a dynamic biomimetic sonarhead inspired by horseshoe bats.

PubMed

Caspers, Philip; Mueller, Rolf

2018-05-24

The noseleaf and pinnae of horseshoe bats (Rhinolophus ferrumequinum) have both been shown to actively deform during biosonar operation. Since these baffle structures directly affect the properties of the animal's biosonar system, this work mimics horseshoe bat sonar system with the goal of developing a platform to study the dynamic sensing principles horseshoe bats employ. Consequently, two robotic devices were developed to mimic the dynamic emission and reception characteristics of horseshoe bats. The noseleaf and pinnae shapes were modeled as smooth blanks matched to digital representations of a horseshoe bat specimen's noseleaf and pinnae. Local shape features mimicking structures on the pinnae and noseleaf were added digitally. Flexible baffles with local shape feature combinations were manufactured and paired with actuation mechanisms to mimic pinnae and noseleaf deformations in-vivo. Two noseleaves with and without local shape features were considered. Each noseleaf baffle was mounted to a platform called the dynamic emission head to actuate three surface elements of the baffle. Similarly, 12 pinna realizations composed of combinations of three local shape features were mounted to a platform called the dynamic reception head to deform the left and right pinnae independently. Motion of the noseleaf and pinnae were synchronized to the incoming and outgoing sonar waveform, and the joint time-frequency properties of the noseleaf and pinnae local feature combinations and combinations of the pinnae and noseleaf thereof were characterized across spatial direction. Amplitude modulations to the outgoing and incoming sonar pulse information across spatial direction were observed for all pinnae and noseleaf local shape feature combinations. Peak modulation variance generated by motion of the pinnae and combinations of the noseleaf and pinnae approached a white Gaussian noise variance bound. However, it was found the dynamic emitter generated less modulation than either the combined or reception scenarios. © 2018 IOP Publishing Ltd.

Attenuation of multiples in image space

NASA Astrophysics Data System (ADS)

Alvarez, Gabriel F.

In complex subsurface areas, attenuation of 3D specular and diffracted multiples in data space is difficult and inaccurate. In those areas, image space is an attractive alternative. There are several reasons: (1) migration increases the signal-to-noise ratio of the data; (2) primaries are mapped to coherent events in Subsurface Offset Domain Common Image Gathers (SODCIGs) or Angle Domain Common Image Gathers (ADCIGs); (3) image space is regular and smaller; (4) attenuating the multiples in data space leaves holes in the frequency-Wavenumber space that generate artifacts after migration. I develop a new equation for the residual moveout of specular multiples in ADCIGs and use it for the kernel of an apex-shifted Radon transform to focus and separate the primaries from specular and diffracted multiples. Because of small amplitude, phase and kinematic errors in the multiple estimate, we need adaptive matching and subtraction to estimate the primaries. I pose this problem as an iterative least-squares inversion that simultaneously matches the estimates of primaries and multiples to the data. Standard methods match only the estimate of the multiples. I demonstrate with real and synthetic data that the method produces primaries and multiples with little cross-talk. In 3D, the multiples exhibit residual moveout in SODCIGs in in-line and cross-line offsets. They map away from zero subsurface offsets when migrated with the faster velocity of the primaries. In ADCIGs the residual moveout of the primaries as a function of the aperture angle, for a given azimuth, is flat for those angles that illuminate the reflector. The multiples have residual moveout towards increasing depth for increasing aperture angles at all azimuths. As a function of azimuth, the primaries have better azimuth resolution than the multiples at larger aperture angles. I show, with a real 3D dataset, that even below salt, where illumination is poor, the multiples are well attenuated in ADCIGs with the new Radon transform in planes of azimuth-stacked ADCIGs. The angle stacks of the estimated primaries show little residual multiple energy.

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…

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.

Post-Service Examination of PWR Baffle Bolts, Part I. Examination and Test Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leonard, Keith J.; Sokolov, Mikhail A.; Gussev, Maxim N.

2015-04-30

In support of extended service and current operations of the US nuclear reactor plants, the Oak Ridge National Laboratory (ORNL), through the Department of Energy (DOE), Light Water Reactor Sustainability (LWRS) Program, is coordinating with Ginna Nuclear Power Plant, The Westinghouse Electric Company, LLC, and ATI Consulting, the selective procurement of baffle bolts that were withdrawn from service in 2011 and currently stored on site at Ginna. The goal of this program is to perform detailed microstructural and mechanical property characterization of baffle former bolts following in-service exposures. This report outlines the selection criteria of the bolts and the techniquesmore » to be used in this study. The bolts available are the original alloy 347 steel fasteners used in holding the baffle plates to the baffle former structures within the lower portion of the pressurized water reactor vessel. Of the eleven possible bolts made available for this work, none were identified to have specific damage. The bolts, however, did show varying levels of breakaway torque required in their removal. The bolts available for this study varied in peak fluence (highest dose within the head of the bolt) between 9.9 and 27.8x10 21 n/cm 2 (E>1MeV). As no evidence for crack initiation was determined for the available bolts from preliminary visual examination, two bolts with the higher fluence values were selected for further post-irradiation examination. The two bolts showed different breakaway torque levels necessary in their removal. The information from these bolts will be integral to the LWRS program initiatives in evaluating end of life microstructure and properties. Furthermore, valuable data will be obtained that can be incorporated into model predictions of long-term irradiation behavior and compared to results obtained in high flux experimental reactor conditions. The two bolts selected for the ORNL study will be shipped to Westinghouse with bolts of interest to their collaborative efforts with the Electric Power Research Institute. Westinghouse will section the ORNL bolts into samples specified in this report and return them to ORNL. Samples will include bend bars for fracture toughness and crack propagation studies along with thin sections from which specimens for bend testing, subscale tensile and microstructural analysis can be obtained. Additional material from the high stress concentration region at the transition between the bolt head and shank will also be preserved to allow for further investigation of possible crack initiation sites.« less

Impact of anatomic characteristics and initial biventricular surgical strategy on outcomes in various forms of double-outlet right ventricle.

PubMed

Villemain, Olivier; Belli, Emre; Ladouceur, Magalie; Houyel, Lucile; Jalal, Zakaria; Lambert, Virginie; Ly, Mohamed; Vouhé, Pascal; Bonnet, Damien

2016-09-01

Surgical management of various forms of double-outlet right ventricle uses a variety of approaches depending on the underlying anatomic form. In this study, we sought to determine the risk factors of mortality and reoperation in those with double-outlet right ventricle undergoing biventricular repair, according to anatomic characteristics and initial surgical strategy. Between 1992 and 2013, 433 patients were included in the study. Double-outlet right ventricle was classified as double-outlet right ventricle with subaortic ventricular septal defect associated with subpulmonary obstruction in 33% of patients (n = 141), with subaortic ventricular septal defect without subpulmonary obstruction in 30% of patients (n = 130), with subpulmonary ventricular septal defect in 32% of patients (n = 139), and with noncommitted ventricular septal defect in 5% of patients (n = 23). Three types of repairs were performed: (1) intraventricular baffle repair, n = 149 (34%); (2) intraventricular baffle repair with right ventricular outflow tract reconstruction, n = 163 (38%); and (3) intraventricular baffle repair with arterial switch operation, n = 121 (28%). Thirty-day overall mortality was 7.4%. Early reoperation was needed in 6% of the cases. Early mortality was higher in the intraventricular baffle repair with arterial switch operation group (P = .01). Survival at 10 years was 86.2%, and freedom from reoperation at 10 years was 61.4%. At last follow-up (median, 5.7 years; 95% confidence interval, 4.5-6.6), mortality and reoperation rates were similar in the different surgical strategy groups. Late reoperation and late mortality were significantly higher in the double-outlet right ventricle with noncommitted ventricular septal defect group (P < .01). In multivariate analyses, risk factors for reoperation were concomitant surgical procedures (P = .03) and duration of cardiopulmonary bypass (P < .01). Risk factors for mortality were restrictive ventricular septal defect (P = .01), mitral cleft (P < .01), and associated coronary artery anomalies (P = .01). Those with the anatomic type of double-outlet right ventricle with noncommitted ventricular septal defect were at higher risk for reoperation and mortality. Intraventricular baffle repair with arterial switch operation was the surgical strategy in patients at higher risk of early death. Initial surgical strategy did not influence the late outcomes. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Metrological characterization methods for confocal chromatic line sensors and optical topography sensors

NASA Astrophysics Data System (ADS)

Seppä, Jeremias; Niemelä, Karri; Lassila, Antti

2018-05-01

The increasing use of chromatic confocal technology for, e.g. fast, in-line optical topography, and measuring thickness, roughness and profiles implies a need for the characterization of various aspects of the sensors. Single-point, line and matrix versions of chromatic confocal technology, encoding depth information into wavelength, have been developed. Of these, line sensors are particularly suitable for in-line process measurement. Metrological characterization and development of practical methods for calibration and checking is needed for new optical methods and devices. Compared to, e.g. tactile methods, optical topography measurement techniques have limitations related to light wavelength and coherence, optical properties of the sample including reflectivity, specularity, roughness and colour, and definition of optical versus mechanical surfaces. In this work, metrological characterization methods for optical line sensors were developed for scale magnification and linearity, sensitivity to sample properties, and dynamic characteristics. An accurate depth scale calibration method using a single prototype groove depth sample was developed for a line sensor and validated with laser-interferometric sample tracking, attaining (sub)micrometre level or better than 0.1% scale accuracy. Furthermore, the effect of different surfaces and materials on the measurement and depth scale was studied, in particular slope angle, specularity and colour. In addition, dynamic performance, noise, lateral scale and resolution were measured using the developed methods. In the case of the LCI1200 sensor used in this study, which has a 11.3 mm  ×  2.8 mm measurement range, the instrument depth scale was found to depend only minimally on sample colour, whereas measuring steeply sloped specular surfaces in the peripheral measurement area, in the worst case, caused a somewhat larger relative sample-dependent change (1%) in scale.

Modeling CO2 distribution in a heterogeneous sandstone reservoir: the Johansen Formation, northern North Sea

NASA Astrophysics Data System (ADS)

Sundal, Anja; Miri, Rohaldin; Petter Nystuen, Johan; Dypvik, Henning; Aagaard, Per

2013-04-01

The last few years there has been broad attention towards finding permanent storage options for CO2. The Norwegian continental margin holds great potential for storage in saline aquifers. Common for many of these reservoir candidates, however, is that geological data are sparse relative to thoroughly mapped hydrocarbon reservoirs in the region. Scenario modeling provides a method for estimating reservoir performances for potential CO2 storage sites and for testing injection strategies. This approach is particularly useful in the evaluation of uncertainties related to reservoir properties and geometry. In this study we have tested the effect of geological heterogeneities in the Johansen Formation, which is a laterally extensive sandstone and saline aquifer at burial depths of 2 - 4 km, proposed as a suitable candidate for CO2 storage by Norwegian authorities. The central parts of the Johansen Formation are underlying the operating hydrocarbon field Troll. In order not to interfere with ongoing gas production, a potential CO2 injection well should be located at a safe distance from the gas reservoir, which consequently implies areas presently without well control. From 3D seismic data, prediction of spatial extent of sandstone is possible to a certain degree, whereas intra-reservoir flow baffles such as draping mudstone beds and calcite cemented layers are below seismic resolution. The number and lateral extent of flow baffles, as well as porosity- and permeability distributions are dependent of sedimentary facies and diagenesis. The interpretation of depositional environment and burial history is thus of crucial importance. A suite of scenario models was established for a potential injection area south of the Troll field. The model grids where made in Petrel based on our interpretations of seismic data, wire line logs, core and cuttings samples. Using Eclipse 300 the distribution of CO2 is modeled for different geological settings; with and without the presence of pervasive low permeability draping mudstone layers, and with varying lateral extent of potential calcite cemented layers in 8 to 15 intra-reservoir depth levels. The modeled area covers 10 x 15.8 km, with a thickness of 110 m at the injection point. Simulations were run with an injection phase of 30 years plus 100 years of migration. The presence of meso-scale flow baffles causes a reduction in vertical permeability in addition to the facies related variation on the micro-scale. Scenarios including potential flow baffles as separate layers in the model grids were compared to scenarios in which the effect of flow baffles were included using harmonic mean average of vertical permeability. The subsequent differences in CO2 distribution are important in estimating the contact area between the plume front and reservoir brine. A heterogeneous reservoir with internal flow baffles is not necessarily a disadvantage as long as sufficient injectivity is maintained within individual sandstone bodies. In each scenario we aim to adapt a suitable injection strategy with respect to utilizing local effects such as the delimitation of gravitational flow, in order to increase reservoir sweep and maximize the effect of trapping mechanisms (i.e. residual, stratigraphic, mineral and dissolution).

An Assessment of Critical Dimension Small Angle X-ray Scattering Metrology for Advanced Semiconductor Manufacturing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Settens, Charles M.

2015-01-01

Simultaneous migration of planar transistors to FinFET architectures, the introduction of a plurality of materials to ensure suitable electrical characteristics, and the establishment of reliable multiple patterning lithography schemes to pattern sub-10 nm feature sizes imposes formidable challenges to current in-line dimensional metrologies. Because the shape of a FinFET channel cross-section immediately influences the electrical characteristics, the evaluation of 3D device structures requires measurement of parameters beyond traditional critical dimension (CD), including their sidewall angles, top corner rounding and footing, roughness, recesses and undercuts at single nanometer dimensions; thus, metrologies require sub-nm and approaching atomic level measurement uncertainty. Synchrotron criticalmore » dimension small angle X-ray scattering (CD-SAXS) has unique capabilities to non-destructively monitor the cross-section shape of surface structures with single nanometer uncertainty and can perform overlay metrology to sub-nm uncertainty. In this dissertation, we perform a systematic experimental investigation using CD-SAXS metrology on a hierarchy of semiconductor 3D device architectures including, high-aspect-ratio contact holes, H2 annealed Si fins, and a series of grating type samples at multiple points along a FinFET fabrication process increasing in structural intricacy and ending with fully fabricated FinFET. Comparative studies between CD-SAXS metrology and other relevant semiconductor dimensional metrologies, particularly CDSEM, CD-AFM and TEM are used to determine physical limits of CD-SAXS approach for advanced semiconductor samples. CD-SAXS experimental tradeoffs, advice for model-dependent analysis and thoughts on the compatibility with a semiconductor manufacturing environment are discussed.« less

Status of the eROSITA Telescope testing and calibrating the x-ray mirror assemblies

NASA Astrophysics Data System (ADS)

Burwitz, Vadim; Predehl, Peter; Bräuninger, Heinrich; Burkert, Wolfgang; Dennerl, Konrad; Eder, Josef; Friedrich, Peter; Fürmetz, Maria; Grisoni, Gabriele; Hartner, Gisela; Marioni, Fabio; Menz, Benedikt; Pfeffermann, Elmar; Valsecchi, Giuseppe

2013-09-01

The eROSITA X-ray observatory that will be launched on board the Russian Spectrum-RG mission comprises seven X-ray telescopes, each with its own mirror assembly (mirror module + X-ray baffle), electron deflector, filter wheel, and CCD camera with its control electronics. The completed flight mirror modules are undergoing many thorough X-ray tests at the PANTHER X-ray test facility after delivery, after being mated with the X-ray baffle, and again after both the vibration and thermal-vacuum tests. A description of the work done with mirror modules/assemblies and the test results obtained will be reported here. We report also on the environmental tests that have been performed on the eROSITA telescope qualification model.

In-line filtration minimizes organ dysfunction: new aspects from a prospective, randomized, controlled trial.

PubMed

Boehne, Martin; Jack, Thomas; Köditz, Harald; Seidemann, Kathrin; Schmidt, Florian; Abura, Michaela; Bertram, Harald; Sasse, Michael

2013-02-06

Infused particles induce thrombogenesis, impair microcirculation and modulate immune response. We have previously shown in critically ill children, that particle-retentive in-line filtration reduced the overall complication rate of severe events, length of stay and duration of mechanical ventilation. We now evaluated the influence of in-line filtration on different organ function and thereby elucidated the potential underlying pathophysiological effects of particle infusion. In this single-centre, prospective, randomized controlled trial 807 critically ill children were assigned to either control (n = 406) or filter group (n = 401), the latter receiving in-line filtration for complete infusion therapy. Both groups were compared regarding the differences of incidence rates and its 95% confidence interval (CI) of different organ dysfunction as defined by the International Pediatric Sepsis Consensus Conference 2005. The incidence rates of respiratory (-5.06%; 95% CI, -9.52 to -0.59%), renal (-3.87%; 95% CI, -7.58 to -0.15%) and hematologic (-3.89%; 95% CI, -7.26 to -0.51%) dysfunction were decreased in the filter group. No difference was demonstrated for the occurrence rates of cardiovascular, hepatic, or neurologic dysfunction between both groups. In-line filtration has beneficial effects on the preservation of hematologic, renal and respiratory function in critically ill patients. The presented clinical data further support our hypothesis regarding potential harmful effects of particles. In critically ill patients infused particles may lead to further deterioration of the microcirculation, induce a systemic hypercoagulability and inflammation with consecutive negative effects on organ function. ClinicalTrials.gov number; NCT00209768.

CFD mixing analysis of axially opposed rows of jets injected into confined crossflow

NASA Technical Reports Server (NTRS)

Bain, D. B.; Smith, C. E.; Holdeman, J. D.

1993-01-01

A computational fluid dynamics (CFD) parametric study was performed to analyze axially opposed rows of jets mixing with crossflow in a rectangular duct. Isothermal analysis was conducted to determine the influence of lateral geometric arrangement on mixing. Two lateral arrangements were analyzed: (1) inline (jets' centerlines aligned with each other on top and bottom walls), and (2) staggered (jets' centerlines offset with each other on top and bottom walls). For a jet-to-mainstream mass flow ratio (MR) of 2.0, design parameters were systematically varied for jet-to-mainstream momentum-flux ratios (J) between 16 and 64 and orifice spacing-to-duct height ratios (S/H) between 0.125 and 1.5. Comparisons were made between geometries optimized for S/H at a specified J. Inline configurations had a unique spacing for best mixing at a specified J. In contrast, staggered configurations had two 'good mixing' spacings for each J, one corresponding to optimum inline spacing and the other corresponding to optimum non-impinging jet spacing. The inline configurations, due to their smaller orifice size at optimum S/H, produced better initial mixing characteristics. At downstream locations (e.g. x/H of 1.5), the optimum non-impinging staggered configuration produced better mixing than the optimum inline configuration for J of 64; the opposite results were observed for J of 16. Increasing J resulted in better mixing characteristics if each configuration was optimized with respect to orifice spacing. Mixing performance was shown to be similar to results from previous dilution jet mixing investigations (MR less than 0.5).

Conventional and phase contrast x-ray imaging techniques and ultrasound imaging method in breast tumor detection: initial comparison studies using phantom

NASA Astrophysics Data System (ADS)

Guo, Yuran; Wu, Di; Omoumi, Farid H.; Li, Yuhua; Wong, Molly Donovan; Ghani, Muhammad U.; Zheng, Bin; Liu, Hong

2018-02-01

The objective of this study was to demonstrate the capability of the high-energy in-line phase contrast imaging in detecting the breast tumors which are undetectable by conventional x-ray imaging but detectable by ultrasound. Experimentally, a CIRS multipurpose breast phantom with heterogeneous 50% glandular and 50% adipose breast tissue was imaged by high-energy in-line phase contrast system, conventional x-ray system and ultrasonography machine. The high-energy in-line phase contrast projection was acquired at 120 kVp, 0.3 mAs with the focal spot size of 18.3 μm. The conventional x-ray projection was acquired at 40 kVp, 3.3 mAs with the focal spot size of 22.26 μm. Both of the x-ray imaging acquisitions were conducted with a unique mean glandular dose of 0.08 mGy. As the result, the high-energy in-line phase contrast system was able to detect one lesion-like object which was also detected by the ultrasonography. This object was spherical shape with the length of about 12.28 mm. Also, the conventional x-ray system was not able to detect any objects. This result indicated the advantages provided by high-energy in-line phase contrast over conventional x-ray system in detecting lesion-like object under the same radiation dose. To meet the needs of current clinical strategies for high-density breasts screening, breast phantoms with higher glandular densities will be employed in future studies.

Blend uniformity evaluation during continuous mixing in a twin screw granulator by in-line NIR using a moving F-test.

PubMed

Fonteyne, Margot; Vercruysse, Jurgen; De Leersnyder, Fien; Besseling, Rut; Gerich, Ad; Oostra, Wim; Remon, Jean Paul; Vervaet, Chris; De Beer, Thomas

2016-09-07

This study focuses on the twin screw granulator of a continuous from-powder-to-tablet production line. Whereas powder dosing into the granulation unit is possible from a container of preblended material, a truly continuous process uses several feeders (each one dosing an individual ingredient) and relies on a continuous blending step prior to granulation. The aim of the current study was to investigate the in-line blending capacity of this twin screw granulator, equipped with conveying elements only. The feasibility of in-line NIR (SentroPAT, Sentronic GmbH, Dresden, Germany) spectroscopy for evaluating the blend uniformity of powders after the granulator was tested. Anhydrous theophylline was used as a tracer molecule and was blended with lactose monohydrate. Theophylline and lactose were both fed from a different feeder into the twin screw granulator barrel. Both homogeneous mixtures and mixing experiments with induced errors were investigated. The in-line spectroscopic analyses showed that the twin screw granulator is a useful tool for in-line blending in different conditions. The blend homogeneity was evaluated by means of a novel statistical method being the moving F-test method in which the variance between two blocks of collected NIR spectra is evaluated. The α- and β-error of the moving F-test are controlled by using the appropriate block size of spectra. The moving F-test method showed to be an appropriate calibration and maintenance free method for blend homogeneity evaluation during continuous mixing. Copyright © 2016 Elsevier B.V. All rights reserved.

Global approach for the validation of an in-line Raman spectroscopic method to determine the API content in real-time during a hot-melt extrusion process.

PubMed

Netchacovitch, L; Thiry, J; De Bleye, C; Dumont, E; Cailletaud, J; Sacré, P-Y; Evrard, B; Hubert, Ph; Ziemons, E

2017-08-15

Since the Food and Drug Administration (FDA) published a guidance based on the Process Analytical Technology (PAT) approach, real-time analyses during manufacturing processes are in real expansion. In this study, in-line Raman spectroscopic analyses were performed during a Hot-Melt Extrusion (HME) process to determine the Active Pharmaceutical Ingredient (API) content in real-time. The method was validated based on a univariate and a multivariate approach and the analytical performances of the obtained models were compared. Moreover, on one hand, in-line data were correlated with the real API concentration present in the sample quantified by a previously validated off-line confocal Raman microspectroscopic method. On the other hand, in-line data were also treated in function of the concentration based on the weighing of the components in the prepared mixture. The importance of developing quantitative methods based on the use of a reference method was thus highlighted. The method was validated according to the total error approach fixing the acceptance limits at ±15% and the α risk at ±5%. This method reaches the requirements of the European Pharmacopeia norms for the uniformity of content of single-dose preparations. The validation proves that future results will be in the acceptance limits with a previously defined probability. Finally, the in-line validated method was compared with the off-line one to demonstrate its ability to be used in routine analyses. Copyright © 2017 Elsevier B.V. All rights reserved.

Pain originating from the sacroiliac joint is a common non-traumatic musculoskeletal complaint in elite inline-speedskaters - an observational study.

PubMed

Ruhe, Alexander; Bos, Tino; Herbert, Arne

2012-03-09

Observational study To investigate common non-traumatic musculoskeletal complaints of the low back in elite inline-speedskaters of the German national team. Traumatic injuries associated with falls or collisions are well documented in speedskaters but so far no studies have investigated non-traumatic low back pain. Previously, the sacroiliac joint was suspected as a frequent origin of complaint, we aimed to investigate this assumption. Two chiropractors examined elite inline-speedskaters of the German national team during three sports events between summer 2010 and 2011. A test cluster of five provocative tests for the sacroiliac joint was selected based on reliability and validity. A total of 37 examinations were conducted on 34 athletes with low back pain during the three sport events. The reported pain intensities ranged from mild to moderate pain (VAS 23.4 ± 13.4 to 35.1 ± 19.2). About 90% of cases showed involvement of the SI joint of which again 90% presented with left sided symptoms. Non-traumatic complaints of the low back originating from the left sacroiliac joint frequently occur in competitive inline speedskaters.

In-line interferometer for broadband near-field scanning optical spectroscopy.

PubMed

Brauer, Jens; Zhan, Jinxin; Chimeh, Abbas; Korte, Anke; Lienau, Christoph; Gross, Petra

2017-06-26

We present and investigate a novel approach towards broad-bandwidth near-field scanning optical spectroscopy based on an in-line interferometer for homodyne mixing of the near field and a reference field. In scattering-type scanning near-field optical spectroscopy, the near-field signal is usually obscured by a large amount of unwanted background scattering from the probe shaft and the sample. Here we increase the light reflected from the sample by a semi-transparent gold layer and use it as a broad-bandwidth, phase-stable reference field to amplify the near-field signal in the visible and near-infrared spectral range. We experimentally demonstrate that this efficiently suppresses the unwanted background signal in monochromatic near-field measurements. For rapid acquisition of complete broad-bandwidth spectra we employ a monochromator and a fast line camera. Using this fast acquisition of spectra and the in-line interferometer we demonstrate the measurement of pure near-field spectra. The experimental observations are quantitatively explained by analytical expressions for the measured optical signals, based on Fourier decomposition of background and near field. The theoretical model and in-line interferometer together form an important step towards broad-bandwidth near-field scanning optical spectroscopy.

Space-Time Joint Interference Cancellation Using Fuzzy-Inference-Based Adaptive Filtering Techniques in Frequency-Selective Multipath Channels

NASA Astrophysics Data System (ADS)

Hu, Chia-Chang; Lin, Hsuan-Yu; Chen, Yu-Fan; Wen, Jyh-Horng

2006-12-01

An adaptive minimum mean-square error (MMSE) array receiver based on the fuzzy-logic recursive least-squares (RLS) algorithm is developed for asynchronous DS-CDMA interference suppression in the presence of frequency-selective multipath fading. This receiver employs a fuzzy-logic control mechanism to perform the nonlinear mapping of the squared error and squared error variation, denoted by ([InlineEquation not available: see fulltext.],[InlineEquation not available: see fulltext.]), into a forgetting factor[InlineEquation not available: see fulltext.]. For the real-time applicability, a computationally efficient version of the proposed receiver is derived based on the least-mean-square (LMS) algorithm using the fuzzy-inference-controlled step-size[InlineEquation not available: see fulltext.]. This receiver is capable of providing both fast convergence/tracking capability as well as small steady-state misadjustment as compared with conventional LMS- and RLS-based MMSE DS-CDMA receivers. Simulations show that the fuzzy-logic LMS and RLS algorithms outperform, respectively, other variable step-size LMS (VSS-LMS) and variable forgetting factor RLS (VFF-RLS) algorithms at least 3 dB and 1.5 dB in bit-error-rate (BER) for multipath fading channels.

Pain originating from the sacroiliac joint is a common non-traumatic musculoskeletal complaint in elite inline-speedskaters - an observational study

PubMed Central

2012-01-01

Study design Observational study Objectives To investigate common non-traumatic musculoskeletal complaints of the low back in elite inline-speedskaters of the German national team. Summary of background data Traumatic injuries associated with falls or collisions are well documented in speedskaters but so far no studies have investigated non-traumatic low back pain. Previously, the sacroiliac joint was suspected as a frequent origin of complaint, we aimed to investigate this assumption. Methods Two chiropractors examined elite inline-speedskaters of the German national team during three sports events between summer 2010 and 2011. A test cluster of five provocative tests for the sacroiliac joint was selected based on reliability and validity. Results A total of 37 examinations were conducted on 34 athletes with low back pain during the three sport events. The reported pain intensities ranged from mild to moderate pain (VAS 23.4 ± 13.4 to 35.1 ± 19.2). About 90% of cases showed involvement of the SI joint of which again 90% presented with left sided symptoms. Conclusions Non-traumatic complaints of the low back originating from the left sacroiliac joint frequently occur in competitive inline speedskaters. PMID:22404796

Monitoring of antisolvent crystallization of sodium scutellarein by combined FBRM-PVM-NIR.

PubMed

Liu, Xuesong; Sun, Di; Wang, Feng; Wu, Yongjiang; Chen, Yong; Wang, Longhu

2011-06-01

Antisolvent crystallization can be used as an alternative to cooling or evaporation for the separation and purification of solid product in the pharmaceutical industry. To improve the process understanding of antisolvent crystallization, the use of in-line tools is vital. In this study, the process analytical technology (PAT) tools including focused beam reflectance measurement (FBRM), particle video microscope (PVM), and near-infrared spectroscopy (NIRS) were utilized to monitor antisolvent crystallization of sodium scutellarein. FBRM was used to monitor chord count and chord length distribution of sodium scutellarein particles in the crystallizer, and PVM, as an in-line video camera, provided pictures imaging particle shape and dimension. In addition, a quantitative model of PLS was established by in-line NIRS to detect the concentration of sodium scutellarein in the solvent and good calibration statistics were obtained (r(2) = 0.976) with the residual predictive deviation value of 11.3. The discussion over sensitivities, strengths, and weaknesses of the PAT tools may be helpful in selection of suitable PAT techniques. These in-line techniques eliminate the need for sample preparation and offer a time-saving approach to understand and monitor antisolvent crystallization process. Copyright © 2011 Wiley-Liss, Inc.

Experimental Investigation on Heat Transfer Characteristics of Different Metallic Fin Arrays

NASA Astrophysics Data System (ADS)

Sangewar, Ravi Kumar

2018-04-01

The reliability of electronic equipment depends on the reliability of the system. For small applications natural convection cooling is sufficient, but for the electronic equipment having number of heat generating components, forced convection cooling is essential. In number of cases, pin fin arrangement is preferred for augmentation of heat transfer. Here, the performance of pin fin array of copper and aluminum material with in-line, as well as staggered arrangement over a flat plate is studied. Constant heat input was given to the inline, staggered arrangement of copper as well as aluminium pin fin arrays. In the present experimental study, heat input and airflow rates are the variables. It was found that the heat transfer coefficient for staggered array is 15% more than that of the in-line array, at the same time pressure drop across the staggered array is more by 10% than the in-line array. The pressure drop was observed to be increasing with increase in flow rate as expected. Endeavor of the present work is to find the optimum spacing between the fins in an array for maximum heat transfer rate, by investigating the heat transfer characteristics.

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. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

High speed phase retrieval of in-line holograms by the assistance of corresponding off-axis holograms.

PubMed

Orzó, László

2015-06-29

Retrieving correct phase information from an in-line hologram is difficult as the object wave field and the diffractions of the zero order and the conjugate object term overlap. The existing iterative numerical phase retrieval methods are slow, especially in the case of high Fresnel number systems. Conversely, the reconstruction of the object wave field from an off-axis hologram is simple, but due to the applied spatial frequency filtering the achievable resolution is confined. Here, a new, high-speed algorithm is introduced that efficiently incorporates the data of an auxiliary off-axis hologram in the phase retrieval of the corresponding in-line hologram. The efficiency of the introduced combined phase retrieval method is demonstrated by simulated and measured holograms.

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.

Calibration transfer of a Raman spectroscopic quantification method for the assessment of liquid detergent compositions from at-line laboratory to in-line industrial scale.

PubMed

Brouckaert, D; Uyttersprot, J-S; Broeckx, W; De Beer, T

2018-03-01

Calibration transfer or standardisation aims at creating a uniform spectral response on different spectroscopic instruments or under varying conditions, without requiring a full recalibration for each situation. In the current study, this strategy is applied to construct at-line multivariate calibration models and consequently employ them in-line in a continuous industrial production line, using the same spectrometer. Firstly, quantitative multivariate models are constructed at-line at laboratory scale for predicting the concentration of two main ingredients in hard surface cleaners. By regressing the Raman spectra of a set of small-scale calibration samples against their reference concentration values, partial least squares (PLS) models are developed to quantify the surfactant levels in the liquid detergent compositions under investigation. After evaluating the models performance with a set of independent validation samples, a univariate slope/bias correction is applied in view of transporting these at-line calibration models to an in-line manufacturing set-up. This standardisation technique allows a fast and easy transfer of the PLS regression models, by simply correcting the model predictions on the in-line set-up, without adjusting anything to the original multivariate calibration models. An extensive statistical analysis is performed in order to assess the predictive quality of the transferred regression models. Before and after transfer, the R 2 and RMSEP of both models is compared for evaluating if their magnitude is similar. T-tests are then performed to investigate whether the slope and intercept of the transferred regression line are not statistically different from 1 and 0, respectively. Furthermore, it is inspected whether no significant bias can be noted. F-tests are executed as well, for assessing the linearity of the transfer regression line and for investigating the statistical coincidence of the transfer and validation regression line. Finally, a paired t-test is performed to compare the original at-line model to the slope/bias corrected in-line model, using interval hypotheses. It is shown that the calibration models of Surfactant 1 and Surfactant 2 yield satisfactory in-line predictions after slope/bias correction. While Surfactant 1 passes seven out of eight statistical tests, the recommended validation parameters are 100% successful for Surfactant 2. It is hence concluded that the proposed strategy for transferring at-line calibration models to an in-line industrial environment via a univariate slope/bias correction of the predicted values offers a successful standardisation approach. Copyright © 2017 Elsevier B.V. All rights reserved.

Design and optimization of anode flow field of a large proton exchange membrane fuel cell for high hydrogen utilization

NASA Astrophysics Data System (ADS)

Yesilyurt, Serhat; Rizwandi, Omid

2016-11-01

We developed a CFD model of the anode flow field of a large proton exchange membrane fuel cell that operates under the ultra-low stoichiometric (ULS) flow conditions which intend to improve the disadvantages of the dead-ended operation such as severe voltage transient and carbon corrosion. Very small exit velocity must be high enough to remove accumulated nitrogen, and must be low enough to retain hydrogen in the active area. Stokes equations are used to model the flow distribution in the flow field, Maxwell-Stefan equations are used to model the transport of the species, and a voltage model is developed to model the reactions kinetics. Uniformity of the distribution of hydrogen concentration is quantified as the normalized area of the region in which the hydrogen mole fraction remains above a certain level, such as 0.9. Geometry of the anode flow field is modified to obtain optimal configuration; the number of baffles at the inlet, width of the gaps between baffles, width of the side gaps, and length of the central baffle are used as design variables. In the final design, the hydrogen-depleted region is less than 0.2% and the hydrogen utilization is above 99%. This work was supported by The Scientific and Technolo-gical Research Council of Turkey, TUBITAK-213M023.

AUTOMATED ANALYSIS OF AQUEOUS SAMPLES CONTAINING PESTICIDES, ACIDIC/BASIC/NEUTRAL SEMIVOLATILES AND VOLATILE ORGANIC COMPOUNDS BY SOLID PHASE EXTRACTION COUPLED IN-LINE TO LARGE VOLUME INJECTION GC/MS

EPA Science Inventory

Data is presented on the development of a new automated system combining solid phase extraction (SPE) with GC/MS spectrometry for the single-run analysis of water samples containing a broad range of organic compounds. The system uses commercially available automated in-line 10-m...

76 FR 18022 - Airworthiness Directives; The Boeing Company Model DC-9-14, DC-9-15, and DC-9-15F Airplanes; and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-01

...: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires installing new in-line fuses for the fuel level float switch and new in-line fuses for... left and right wing forward spars, center wing forward spar, forward auxiliary fuel tank, and aft...

Malaligned dynamic anterior cervical plate: a biomechanical analysis of effectiveness.

PubMed

Lawrence, Brandon D; Patel, Alpesh A; Guss, Andrew; Ryan Spiker, W; Brodke, Darrel S

2014-12-01

Biomechanical evaluation. To evaluate the kinematic and load-sharing differences of dynamic anterior cervical plates when placed in-line at 0° and off-axis at 20°. The use of dynamic anterior cervical plating systems has recently gained popularity due to the theoretical benefit of improved load sharing with graft subsidence. Occasionally, due to anatomical restraints, the anterior cervical plate may be placed off-axis in the coronal plane. This may potentially decrease the dynamization capability of the plate, leading to less load sharing and potentially decreased fusion rates. The purpose of this study was to comprehensively evaluate the kinematic and load-sharing differences of a dynamic plate placed in-line versus off-axis in the coronal plane. Thirteen fresh-frozen human cadaveric cervical spines (C2-T1) were used. Nondestructive range-of-motion testing was performed with a pneumatically controlled spine simulator in flexion/extension, lateral bending, and axial rotation using the OptoTrak motion measurement system. A C5 corpectomy was performed, and a custom interbody spacer with an integrated load cell collected load-sharing data under axial compression at varying loads. A dynamic anterior cervical plate was placed in-line at 0° and then off-axis at 20°. Testing conditions ensued using a full-length spacer, followed by simulated subsidence by removing 10% of the height of the original spacer. There were no kinematic differences noted in the in-line model versus the off-axis model. After simulated subsidence, the small decreases in stiffness and increases in motion were similar whether the plate was placed in-line or off-axis in all 3 planes of motion. There were also no significant differences in the load-sharing characteristics of the in-line plate versus the off-axis plate in either the full-length model or the subsided interbody model. This study suggests that off-axis dynamic plate positioning does not significantly impact construct kinematics or graft load sharing. As such, we do not recommend removal or repositioning of an off-axis placed dynamic plate because the kinematic and load-sharing biomechanical properties are similar. N/A.

Sixty-four-Channel Inline Cable Tester

NASA Technical Reports Server (NTRS)

2008-01-01

Faults in wiring are a serious concern for the aerospace and aeronautics (commercial, military, and civil) industries. A number of accidents have occurred because faulty wiring created shorts or opens that resulted in the loss of control of the aircraft or because arcing led to fires and explosions. Some of these accidents have resulted in the massive loss of lives (such as in the TWA Flight 800 accident). Circuits on the Space Shuttle have also failed because of faulty insulation on wiring. STS-93 lost power when a primary power circuit in one engine failed and a second engine had a backup power circuit fault. Cables are usually tested on the ground after the crew reports a fault encountered during flight. Often such failures result from vibration and cannot be replicated while the aircraft is stationary. It is therefore important to monitor faults while the aircraft is in operation, when cables are more likely to fail. Work is in progress to develop a cable fault tester capable of monitoring up to 64 individual wires simultaneously. Faults can be monitored either inline or offline. In the inline mode of operation, the monitoring is performed without disturbing the normal operation of the wires under test. That is, the operations are performed unintrusively and are essentially undetectable for the test signal levels are below the noise floor. A cable can be monitored several times per second in the offline mode and once a second in the inline mode. The 64-channel inline cable tester not only detects the occurrence of a fault, but also determines the type of fault (short/open) and the location of the fault. This will enable the detection of intermittent faults that can be repaired before they become serious problems.

The use of tracheostomy speaking valves in mechanically ventilated patients results in improved communication and does not prolong ventilation time in cardiothoracic intensive care unit patients.

PubMed

Sutt, Anna-Liisa; Cornwell, Petrea; Mullany, Daniel; Kinneally, Toni; Fraser, John F

2015-06-01

The aim of this study was to assess the effect of the introduction of in-line tracheostomy speaking valves (SVs) on duration of mechanical ventilation and time to verbal communication in patients requiring tracheostomy for prolonged mechanical ventilation in a predominantly cardiothoracic intensive care unit (ICU). We performed a retrospective preobservational-postobservational study using data from the ICU clinical information system and medical record. Extracted data included demographics, diagnoses and disease severity, mechanical ventilation requirements, and details on verbal communication and oral intake. Data were collected on 129 patients. Mean age was 59 ± 16 years, with 75% male. Demographics, case mix, and median time from intubation to tracheostomy (6 days preimplementation-postimplementation) were unchanged between timepoints. A significant decrease in time from tracheostomy to establishing verbal communication was observed (18 days preimplementation and 9 days postimplementation, P <.05). There was no difference in length of mechanical ventilation (20 days preimplementation-post) or time to decannulation (14 days preimplementation-postimplementation). No adverse events were documented in relation to the introduction of in-line SVs. In-line SVs were successfully implemented in mechanically ventilated tracheostomized patient population. This resulted in earlier verbal communication, no detrimental effect on ventilator weaning times, and no change in decannulation times. The purpose of the study was to compare tracheostomy outcomes in mechanically ventilated patients in a cardiothoracic ICU preintroduction and postintroduction of in-line SVs. It was hypothesized that in-line SVs would improve communication and swallowing specific outcomes with no increase in average time to decannulation or the number of adverse events. Copyright © 2015 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Speetjens, M. F. M.; Demissie, E. A.; Metcalfe, G.

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 zonesmore » 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 suitability for (at least first exploratory) studies on (qualitative) mixing properties.« less

Various methods to improve heat transfer in exchangers

NASA Astrophysics Data System (ADS)

Pavel, Zitek; Vaclav, Valenta

2015-05-01

The University of West Bohemia in Pilsen (Department of Power System Engineering) is working on the selection of effective heat exchangers. Conventional shell and tube heat exchangers use simple segmental baffles. It can be replaced by helical baffles, which increase the heat transfer efficiency and reduce pressure losses. Their usage is demonstrated in the primary circuit of IV. generation MSR (Molten Salt Reactors). For high-temperature reactors we consider the use of compact desk heat exchangers, which are small, which allows the integral configuration of reactor. We design them from graphite composites, which allow up to 1000°C and are usable as exchangers: salt-salt or salt-acid (e.g. for the hydrogen production). In the paper there are shown thermo-physical properties of salts, material properties and principles of calculations.

Evaluation of the infrared test method for the olympus thermal balance tests

NASA Technical Reports Server (NTRS)

Donato, M.; Stpierre, D.; Green, J.; Reeves, M.

1986-01-01

The performance of the infrared (IR) rig used for the thermal balance testing of the Olympus S/C thermal model is discussed. Included in this evaluation are the rig effects themselves, the IRFLUX computer code used to predict the radiation inputs, the Monitored Background Radiometers (MBR's) developed to measure the absorbed radiation flux intensity, the Uniform Temperature Reference (UTR) based temperature measurement system and the data acquisition system. A preliminary set of verification tests were performed on a 1 m x 1 m zone to assess the performance of the IR lamps, calrods, MBR's and aluminized baffles. The results were used, in part, to obtain some empirical data required for the IRFLUX code. This data included lamp and calrod characteristics, the absorptance function for various surface types, and the baffle reflectivities.

External combustion engine having a combustion expansion chamber

NASA Astrophysics Data System (ADS)

Duva, Anthony W.

1993-03-01

This patent application discloses an external combustion engine having a combustion expansion chamber. The engine includes a combustion chamber for generating a high-pressure, energized gas from a monopropellant fuel, and a cylinder for receiving the energized gas through a rotary valve to perform work on a cylinder disposed therein. A baffle plate is positioned between the combustion area and expansion area for reducing the pressure of the gas. The combustion area and expansion area are separated by a baffle plate having a flow area which is sufficiently large to eliminate the transmission of pressure pulsations from the combustion area to the expansion area while being small enough to provide for substantially complete combustion in the combustion area. The engine is particularly well suited for use in a torpedo.

Resource Sharing via Planed Relay for [InlineEquation not available: see fulltext.

NASA Astrophysics Data System (ADS)

Shen, Chong; Rea, Susan; Pesch, Dirk

2008-12-01

We present an improved version of adaptive distributed cross-layer routing algorithm (ADCR) for hybrid wireless network with dedicated relay stations ([InlineEquation not available: see fulltext.]) in this paper. A mobile terminal (MT) may borrow radio resources that are available thousands mile away via secure multihop RNs, where RNs are placed at pre-engineered locations in the network. In rural places such as mountain areas, an MT may also communicate with the core network, when intermediate MTs act as relay node with mobility. To address cross-layer network layers routing issues, the cascaded ADCR establishes routing paths across MTs, RNs, and cellular base stations (BSs) and provides appropriate quality of service (QoS). We verify the routing performance benefits of [InlineEquation not available: see fulltext.] over other networks by intensive simulation.

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.

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

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.

Comments on: Christensen, N., and Lawrie, K., 2012. Resolution analyses for selecting an appropriate airborne electromagnetic (AEM) system, Exploration Geophysics, 43, 213-227

NASA Astrophysics Data System (ADS)

Smiarowski, Adam; Mulè, Shane

2015-06-01

The AEM in-line component is added to the posterior model covariance matrix analysis done by Christensen and Lawrie, who estimated resolution of data in an inversion program. They compared two AEM systems: SkyTEM and CGG's TEMPEST™. Here, we clarify points made about TEMPEST™ and extend the analysis to include the in-line component.

Process analytical technology to understand the disintegration behavior of alendronate sodium tablets.

PubMed

Xu, Xiaoming; Gupta, Abhay; Sayeed, Vilayat A; Khan, Mansoor A

2013-05-01

Various adverse events including esophagus irritations have been reported with the use of alendronate tablets, likely attributed to the rapid tablet disintegration in the mouth or esophagus. Accordingly, the disintegration of six alendronate tablet drug products was studied using a newly developed testing device equipped with in-line sensors, in addition to the official compendial procedure for measuring the disintegration time. The in-line sensors were used to monitor the particle count and solution pH change to assess the onset and duration of disintegration. A relatively large variation was observed in the disintegration time of the tested drug products using the compendial method. The data collected using the in-line sensors suggested that all tested drug products exhibited almost instantaneous onset of disintegration, under 2 s, and a sharp drop in solution pH. The drop in pH was slower for tablets with slower disintegration. The in-house prepared alendronate test tablets also showed similar trends suggesting rapid solubilization of the drug contributed to the fast tablet disintegration. This research highlights the usefulness of the newly developed in-line analytical method in combination with the compendial method in providing a better understanding of the disintegration and the accompanying drug solubilization processes for fast disintegrating tablet drug products. Copyright © 2013 Wiley Periodicals, Inc.

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.

Laser based thermo-conductometry as an approach to determine ribbon solid fraction off-line and in-line.

PubMed

Wiedey, Raphael; Šibanc, Rok; Kleinebudde, Peter

2018-06-06

Ribbon solid fraction is one of the most important quality attributes during roll compaction/dry granulation. Accurate and precise determination is challenging and no in-line measurement tool has been generally accepted, yet. In this study, a new analytical tool with potential off-line as well as in-line applicability is described. It is based on the thermo-conductivity of the compacted material, which is known to depend on the solid fraction. A laser diode was used to punctually heat the ribbon and the heat propagation monitored by infrared thermography. After performing a Gaussian fit of the transverse ribbon profile, the scale parameter σ showed correlation to ribbon solid fraction in off-line as well as in-line studies. Accurate predictions of the solid fraction were possible for a relevant range of process settings. Drug stability was not affected, as could be demonstrated for the model drug nifedipine. The application of this technique was limited when using certain fillers and working at higher roll speeds. This study showed the potentials of this new technique and is a starting point for additional work that has to be done to overcome these challenges. Copyright © 2018 Elsevier B.V. All rights reserved.

Analysis of the Electronic Structure of the Special Pair of a Bacterial Photosynthetic Reaction Center by 13 C Photochemically Induced Dynamic Nuclear Polarization Magic-Angle Spinning NMR Using a Double-Quantum Axis.

PubMed

Najdanova, Marija; Gräsing, Daniel; Alia, A; Matysik, Jörg

2018-01-01

The origin of the functional symmetry break in bacterial photosynthesis challenges since several decades. Although structurally very similar, the two branches of cofactors in the reaction center (RC) protein complex act very differently. Upon photochemical excitation, an electron is transported along one branch, while the other remains inactive. Photochemically induced dynamic nuclear polarization (photo-CIDNP) magic-angle spinning (MAS) 13 C NMR revealed that the two bacteriochlorophyll cofactors forming the "Special Pair" donor dimer are already well distinguished in the electronic ground state. These previous studies are relying solely on 13 C- 13 C correlation experiments as radio-frequency-driven recoupling (RFDR) and dipolar-assisted rotational resonance (DARR). Obviously, the chemical-shift assignment is difficult in a dimer of tetrapyrrole macrocycles, having eight pyrrole rings of similar chemical shifts. To overcome this problem, an INADEQUATE type of experiment using a POST C7 symmetry-based approach is applied to selectively isotope-labeled bacterial RC of Rhodobacter (R.) sphaeroides wild type (WT). We, therefore, were able to distinguish unresolved sites of the macromolecular dimer. The obtained chemical-shift pattern is in-line with a concentric assembly of negative charge within the common center of the Special Pair supermolecule in the electronic ground state. © 2017 The American Society of Photobiology.

UV water disinfector

DOEpatents

Gadgil, Ashok; Garud, Vikas

1998-07-14

A UV disinfector with a gravity driven feed water delivery system, and an air-suspended bare UV lamp. The disinfector is hydrodynamically optimized with a laminerizing, perforated baffle wall, beveled treatment chamber, and outlet weir.

Film condensation of steam flowing downward on a tier of horizontal cylinders at different inclination angles in the presence of a non-condensable gas

NASA Astrophysics Data System (ADS)

Ramadan, Abdulghani; Yamali, Cemil

2013-12-01

The problem of forced laminar film condensation of steam flowing downward a tier of horizontal cylinders is investigated numerically. The effects of free stream non-condensable gas, air concentration (m1,∞), free stream velocity (Reynolds number), cylinder diameter, and angle of inclination on the condensation heat transfer are analyzed. Two flow arrangements, inline and staggered, are analyzed and investigated. The mathematical model takes into account the effect of staggering of the cylinders and how condensation is affected at the lower cylinders when condensate does not fall on to the center line of the cylinders. Condensation heat transfer results are available in ranges from (U∞ = 1 - 30 m/s) for free stream velocity, (m1,∞ = 0.01 -0.8) for free stream air mass fraction and (D = 12.7 -50.8 mm) for cylinder diameter. Results show that; a remarked reduction in the vapor side heat transfer coefficient is noticed. This results from the presence of small amounts of free stream air mass fractions in the steam-air mixture and increase in the cylinder diameter. On the other hand, it increases by increasing the free stream velocity (Reynolds number). Average heat transfer coefficient at the middle and the bottom cylinders increases by increasing the angle of inclination, whereas, no significant change is observed for that of the upper cylinder. Down the bank, a rapid decrease in the vapor side heat transfer coefficient is noticed. It may be resulted from the combined effects of inundation, decrease in the vapor velocity and increase in the non-condensable gas (air) at the bottom cylinders in the bank.

Effect of seed age on gold nanorod formation. A microfluidic, real-time investigation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watt, John; Hance, Bradley G.; Anderson, Rachel S.

We report a real time investigation into the effect of seed age on the growth of gold nanorods using a microfluidic reaction apparatus. Through small-angle X-ray scattering (SAXS) and ultraviolet–visible spectroscopy (UV–vis) analysis, we observe the seeds aging in accordance with Ostwald ripening. A seed solution is then aged in situ and continuously injected into a microfluidic chip to initiate rod growth. We track nanorod formation in real time using in-line ultraviolet–visible and near-infrared (UV–vis–NIR) monitoring and observe a dramatic decrease in yield with increasing seed age. We then demonstrate that, by diluting the gold seed solution immediately following synthesis,more » the rate of aging can be reduced and nanorods synthesized continuously, in good yield. As a result, these findings suggest ultrasmall, catalytically active seeds, which are rapidly lost due to ripening and are critical for the formation of gold nanorods.« less

An investigation of hydraulic-line resonance and its attenuation

NASA Technical Reports Server (NTRS)

Sewall, J. L.; Wineman, D. A.; Herr, R. W.

1973-01-01

An investigation of fluid resonance in high-pressure hydraulic lines has been made with two types of fluid dampers (or filters) installed in the line. One type involved the use of one or more closed-end tubes branching at right angles from a main line, and the other type was a fluid muffler installed in-line. These devices were evaluated in forced vibration tests with oscillatory disturbances over a 1000-Hz range applied to one end of the line and with oscillatory pressures measured at various stations along the main pipe. Limited applications of acoustic-wave theory to the branched systems are also included. Results show varying attenuations of pressure perturbations, depending on the number and location of branches and the type of muffler. Up to three branches were used in the branch-resonator study, and the largest frequency range with maximum attenuation was obtained for a three-branch configuration. The widest frequency ranges with significant attenuations were obtained with two types of fluid mufflers.

Effect of seed age on gold nanorod formation. A microfluidic, real-time investigation

DOE PAGES

Watt, John; Hance, Bradley G.; Anderson, Rachel S.; ...

2015-09-02

We report a real time investigation into the effect of seed age on the growth of gold nanorods using a microfluidic reaction apparatus. Through small-angle X-ray scattering (SAXS) and ultraviolet–visible spectroscopy (UV–vis) analysis, we observe the seeds aging in accordance with Ostwald ripening. A seed solution is then aged in situ and continuously injected into a microfluidic chip to initiate rod growth. We track nanorod formation in real time using in-line ultraviolet–visible and near-infrared (UV–vis–NIR) monitoring and observe a dramatic decrease in yield with increasing seed age. We then demonstrate that, by diluting the gold seed solution immediately following synthesis,more » the rate of aging can be reduced and nanorods synthesized continuously, in good yield. As a result, these findings suggest ultrasmall, catalytically active seeds, which are rapidly lost due to ripening and are critical for the formation of gold nanorods.« less

Perception SoC Based on an Ultrasonic Array of Sensors: Efficient DSP Core Implementation and Subsequent Experimental Results

NASA Astrophysics Data System (ADS)

Kassem, A.; Sawan, M.; Boukadoum, M.; Haidar, A.

2005-12-01

We are concerned with the design, implementation, and validation of a perception SoC based on an ultrasonic array of sensors. The proposed SoC is dedicated to ultrasonic echography applications. A rapid prototyping platform is used to implement and validate the new architecture of the digital signal processing (DSP) core. The proposed DSP core efficiently integrates all of the necessary ultrasonic B-mode processing modules. It includes digital beamforming, quadrature demodulation of RF signals, digital filtering, and envelope detection of the received signals. This system handles 128 scan lines and 6400 samples per scan line with a[InlineEquation not available: see fulltext.] angle of view span. The design uses a minimum size lookup memory to store the initial scan information. Rapid prototyping using an ARM/FPGA combination is used to validate the operation of the described system. This system offers significant advantages of portability and a rapid time to market.

Solution In-Line Alpha Counter (SILAC) Instruction Manual-Version 4.00

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steven M. Alferink; Joel E. Farnham; Malcolm M. Fowler

2002-06-01

The Solution In-Line Alpha Counter (SILAC) provides near real-time alpha activity measurements of aqueous solutions in gloveboxes located in the Plutonium Facility (TA-55) at Los Alamos National Laboratory (LANL). The SILAC detector and its interface software were first developed by Joel Farnham at LANL [1]. This instruction manual describes the features of the SILAC interface software and contains the schematic and fabrication instructions for the detector.

Flow Characteristics and Status of CFD Hydrodynamic Model Development in Sudden Contraction Manifold/Orifice Configurations

DTIC Science & Technology

2011-07-01

Branching Configuration 33 6.6 CONTRACTION COEFFICIENT 35 7.0 SUPERCAVITATION 36 7.1 FLOW REATTACHMENT 36 7.1.1 In-Line... SUPERCAVITATION 37 7.2.1 In-Line Configuration Critical Cavitation 37 7.2.2 Dead Head Configuration Critical Cavitation 38 7.2.3 Approach...regimes are: (1) Non-Cavitation, (2) Inception of Cavitation, (3) Full Cavitation, (4) Supercavitation , and (5) Hydraulic Flip. The flow

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.

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.

Using digital inline holographic microscopy and quantitative phase contrast imaging to assess viability of cultured mammalian cells

NASA Astrophysics Data System (ADS)

Missan, Sergey; Hrytsenko, Olga

2015-03-01

Digital inline holographic microscopy was used to record holograms of mammalian cells (HEK293, B16, and E0771) in culture. The holograms have been reconstructed using Octopus software (4Deep inwater imaging) and phase shift maps were unwrapped using the FFT-based phase unwrapping algorithm. The unwrapped phase shifts were used to determine the maximum phase shifts in individual cells. Addition of 0.5 mM H2O2 to cell media produced rapid rounding of cultured cells, followed by cell membrane rupture. The cell morphology changes and cell membrane ruptures were detected in real time and were apparent in the unwrapped phase shift images. The results indicate that quantitative phase contrast imaging produced by the digital inline holographic microscope can be used for the label-free real time automated determination of cell viability and confluence in mammalian cell cultures.

A New Pipelined Systolic Array-Based Architecture for Matrix Inversion in FPGAs with Kalman Filter Case Study

NASA Astrophysics Data System (ADS)

Bigdeli, Abbas; Biglari-Abhari, Morteza; Salcic, Zoran; Tin Lai, Yat

2006-12-01

A new pipelined systolic array-based (PSA) architecture for matrix inversion is proposed. The pipelined systolic array (PSA) architecture is suitable for FPGA implementations as it efficiently uses available resources of an FPGA. It is scalable for different matrix size and as such allows employing parameterisation that makes it suitable for customisation for application-specific needs. This new architecture has an advantage of[InlineEquation not available: see fulltext.] processing element complexity, compared to the[InlineEquation not available: see fulltext.] in other systolic array structures, where the size of the input matrix is given by[InlineEquation not available: see fulltext.]. The use of the PSA architecture for Kalman filter as an implementation example, which requires different structures for different number of states, is illustrated. The resulting precision error is analysed and shown to be negligible.

Automating multistep flow synthesis: approach and challenges in integrating chemistry, machines and logic

PubMed Central

Shukla, Chinmay A

2017-01-01

The implementation of automation in the multistep flow synthesis is essential for transforming laboratory-scale chemistry into a reliable industrial process. In this review, we briefly introduce the role of automation based on its application in synthesis viz. auto sampling and inline monitoring, optimization and process control. Subsequently, we have critically reviewed a few multistep flow synthesis and suggested a possible control strategy to be implemented so that it helps to reliably transfer the laboratory-scale synthesis strategy to a pilot scale at its optimum conditions. Due to the vast literature in multistep synthesis, we have classified the literature and have identified the case studies based on few criteria viz. type of reaction, heating methods, processes involving in-line separation units, telescopic synthesis, processes involving in-line quenching and process with the smallest time scale of operation. This classification will cover the broader range in the multistep synthesis literature. PMID:28684977

Methods for the continuous production of plastic scintillator materials

DOEpatents

Bross, Alan; Pla-Dalmau, Anna; Mellott, Kerry

1999-10-19

Methods for producing plastic scintillating material employing either two major steps (tumble-mix) or a single major step (inline-coloring or inline-doping). Using the two step method, the polymer pellets are mixed with silicone oil, and the mixture is then tumble mixed with the dopants necessary to yield the proper response from the scintillator material. The mixture is then placed in a compounder and compounded in an inert gas atmosphere. The resultant scintillator material is then extruded and pelletized or formed. When only a single step is employed, the polymer pellets and dopants are metered into an inline-coloring extruding system. The mixture is then processed under a inert gas atmosphere, usually argon or nitrogen, to form plastic scintillator material in the form of either scintillator pellets, for subsequent processing, or as material in the direct formation of the final scintillator shape or form.

The optical lens coupled X-ray in-line phase contrast imaging system for the characterization of low Z materials

NASA Astrophysics Data System (ADS)

Wang, Kai; Lin, Wei; Dai, Fei; Li, Jun; Qi, Xiaobo; Lei, Haile; Liu, Yuanqiong

2018-05-01

Due to the high spatial resolution and contrast, the optical lens coupled X-ray in-line phase contrast imaging system with the secondary optical magnification is more suitable for the characterization of the low Z materials. The influence of the source to object distance and the object to scintillator distance on the image resolution and contrast is studied experimentally. A phase correlation algorithm is used for the image mosaic of a serial of X-ray phase contrast images acquired with high resolution, the resulting resolution is less than 1.0 μm, and the whole field of view is larger than 1.4 mm. Finally, the geometric morphology and the inner structure of various weakly absorbing samples and the evaporation of water in the plastic micro-shell are in situ characterized by the optical lens coupled X-ray in-line phase contrast imaging system.

In-line ATR-UV and Raman Spectroscopy for Monitoring API Dissolution Process During Liquid-Filled Soft-Gelatin Capsule Manufacturing.

PubMed

Wan, Boyong; Zordan, Christopher A; Lu, Xujin; McGeorge, Gary

2016-10-01

Complete dissolution of the active pharmaceutical ingredient (API) is critical in the manufacturing of liquid-filled soft-gelatin capsules (SGC). Attenuated total reflectance UV spectroscopy (ATR-UV) and Raman spectroscopy have been investigated for in-line monitoring of API dissolution during manufacturing of an SGC product. Calibration models have been developed with both techniques for in-line determination of API potency. Performance of both techniques was evaluated and compared. The ATR-UV methodology was found to be able to monitor the dissolution process and determine the endpoint, but was sensitive to temperature variations. The Raman technique was also capable of effectively monitoring the process and was more robust to the temperature variation and process perturbations by using an excipient peak for internal correction. Different data preprocessing methodologies were explored in an attempt to improve method performance.

Detachment experiments in new DIII-D upper divertor

NASA Astrophysics Data System (ADS)

Moser, A. L.; Leonard, A. W.; Groebner, R. J.; Guo, H.; Wang, H.; Watkins, J. G.; McLean, A. G.; Fenstermacher, M. E.; Shafer, M. W.; Briesemeister, A. R.; Hinson, E. T.

2017-10-01

Installation of the Small Angle Slot (SAS) in the upper divertor of DIII-D enables new studies of the effect of target and baffle geometry on divertor detachment. This structure provides a more-closed upper divertor as well as the SAS divertor itself. Initial SAS experiment results indicate that divertor detachment occurs at a lower line-averaged density than in the more-open, lower single null divertor configurations on DIII-D. In contrast, the increased divertor closure of the new installation did not reduce the upstream density required for detachment beyond that achieved with the previous upper divertor structure. Particle pumping in the upper divertor structure is found to produce a 10 % reduction in the pedestal density required for detachment compared to the case with no pumping. Comparisons focus on both the onset of detachment (measured by in-target Langmuir probes) as a function of upstream density, as well as the effect of the new divertor configurations on pedestal density profiles. Work supported by US DOE under DE-FC02-04ER54698, DE-AC05-00OR22725, DE-AC04-94AL85000, DE-AC52-07NA27344, and DE-SC00013911.

Fluid surface behavior in low gravity. Center discretionary fund no. 83-21

NASA Technical Reports Server (NTRS)

Leslie, F.; Gans, R. F.; Schafer, C.

1985-01-01

Measurements of rotating equilibrium bubble shapes in the low-gravity environment of a free-falling aircraft are presented. Emphasis is placed on bubbles which intersect the container boundaries. These data are compared with theoretical profiles derived from Laplace's formula and are in good agreement with the measurements. Two types of instability are explored. The first occurs when the baffle spacing is too large for the bubble to intersect both the top and bottom boundaries. The second occurs when the hydrostatic pressure beneath a displaced free surface does not compensate for pressure change due to capillary forces. The interface shape depends on the contact angle, the radius of intersection with container, and the parameter F which is a measure of the relative importance of centrifugal force to surface tension. For isolated bubbles, F has a maximum value of 1/2. A further increase in F causes the bubble to break contact with the axis of rotation. For large values of F, the bubble becomes more cylindrical and the capillary rise occurs over a thinner layer so that the small radius of curvature can generate enough pressure drop to balance the increased hydrostatic contribution.

First results from the Thomson scattering diagnostic on proto-MPEX.

PubMed

Biewer, T M; Meitner, S; Rapp, J; Ray, H; Shaw, G

2016-11-01

A Thomson scattering (TS) diagnostic has been successfully implemented on the prototype Material Plasma Exposure eXperiment (Proto-MPEX) at Oak Ridge National Laboratory. The diagnostic collects the light scattered by plasma electrons and spectroscopically resolves the Doppler shift imparted to the light by the velocity of the electrons. The spread in velocities is proportional to the electron temperature, while the total number of photons is proportional to the electron density. TS is a technique used on many devices to measure the electron temperature (T e ) and electron density (n e ) of the plasma. A challenging aspect of the technique is to discriminate the small number of Thomson scattered photons against the large peak of background photons from the high-power laser used to probe the plasma. A variety of methods are used to mitigate the background photons in Proto-MPEX, including Brewster angled windows, viewing dumps, and light baffles. With these methods, first results were measured from argon plasmas in Proto-MPEX, indicating T e ∼ 2 eV and n e ∼ 1 × 10 19 m -3 . The configuration of the Proto-MPEX TS diagnostic will be described and plans for improvement will be given.

First results from the Thomson scattering diagnostic on Proto-MPEX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biewer, Theodore M; Meitner, Steven J; Rapp, Juergen

2016-01-01

A Thomson scattering diagnostic has been successfully implemented on the prototype Material Plasma Exposure eXperiment (Proto-MPEX) at Oak Ridge National Laboratory. The diagnostic collects the light scattered by plasma electrons and spectroscopically resolves the Doppler shift imparted to the light by the velocity of the electrons. The spread in velocities is proportional to the electron temperature, while the total number of photons is proportional to the electron density. Thomson scattering is a technique used on many devices to measure the electron temperature (Te) and electron density (ne) of the plasma. A challenging aspect of the technique is to discriminate themore » small number of Thomson scattered photons against the large peak of background photons from the high-power laser used to probe the plasma. A variety of methods are used to mitigate the background photons in Proto-MPEX, including Brewster angled windows, viewing dumps, and light baffles. With these methods, first results were measured from Argon plasmas in Proto-MPEX, indicating Te ~ 2 eV and ne ~ 1x1019 m-3. The configuration of the Proto-MPEX Thomson scattering diagnostic will be described and plans for improvement will be given.« less

A new star (sensor) is born

NASA Astrophysics Data System (ADS)

Leijtens, Johan; Vliegenthart, Willem; Lampridis, Dimitris; Vacanti, Giuseppe; Monna, Bert; Bechthum, Elbert; Hagenaars, Koen; van der Heide, Erik; Kruijff, Michiel; van Breukelen, Eddie; LeMair, Anita

2017-11-01

In the frame of the Dutch Prequalification for ESA Programs(PEP), as part of the efforts to design an integrated optical attitude control subsytem (IOPACS), a consortium of TNO and several SME's in the Netherlands have been working on a novel type of startracker called MABS (Multiple Aperture Baffled Startracker). The system comprises a single cast metal housing with four reflective optical telescopes which use only structural internal baffling. Inherent to the design are a very high stability and excellent co-alignment between the apertures, a significant decrease in system size and low recurring production cost. The concept is a radical change from more common multiple startracker setups. The presentation will concentrate on the validity of the concept, the predicted performance and benefits for space applications, the produced breadboard and measured performances as well as the costing aspects.

HOMOGENEOUS NUCLEAR REACTOR

DOEpatents

Hammond, R.P.; Busey, H.M.

1959-02-17

Nuclear reactors of the homogeneous liquid fuel type are discussed. The reactor is comprised of an elongated closed vessel, vertically oriented, having a critical region at the bottom, a lower chimney structure extending from the critical region vertically upwardly and surrounded by heat exchanger coils, to a baffle region above which is located an upper chimney structure containing a catalyst functioning to recombine radiolyticallydissociated moderator gages. In operation the liquid fuel circulates solely by convection from the critical region upwardly through the lower chimney and then downwardly through the heat exchanger to return to the critical region. The gases formed by radiolytic- dissociation of the moderator are carried upwardly with the circulating liquid fuel and past the baffle into the region of the upper chimney where they are recombined by the catalyst and condensed, thence returning through the heat exchanger to the critical region.

Experimental investigation of heat transfer and pressure drop characteristics of non-Newtonian nanofluids flowing in the shell-side of a helical baffle heat exchanger with low-finned tubes

NASA Astrophysics Data System (ADS)

Tan, Yunkai; He, Zhenbin; Xu, Tao; Fang, Xiaoming; Gao, Xuenong; Zhang, Zhengguo

2017-09-01

An aqueous solution of Xanthan Gum (XG) at a weight fraction as high as 0.2% was used as the base liquid, the stable MWCNTs-dispersed non-Newtonian nanofluids at different weight factions of MWCNTs was prepared. The base fluid and all nanofluids show pseudoplastic (shear-thinning) rheological behavior. Experiments were performed to compare the shell-side forced convective heat transfer coefficient and pressure drop of non-Newtonian nanofluids to those of non-Newtonian base fluid in an integrally helical baffle heat exchanger with low-finned tubes. The experimental results showed that the enhancement of the convective heat transfer coefficient increases with an increase in the Peclet number and the nanoparticle concentration. For nanofluids with 1.0, 0.5 and 0.2 wt% of multi-walled carbon nanotubes (MWCNTs), the heat transfer coefficients respectively augmented by 24.3, 13.2 and 4.7% on average and the pressure drops become larger than those of the base fluid. The comprehensive thermal performance factor is higher than one and increases with an increasing weight fraction of MWCNTs. A remarkable heat transfer enhancement in the shell side of helical baffle heat exchanger with low-finned tubes can be obtained by adding MWCNTs into XG aqueous solution based on thermal resistance analysis. New correlations have been suggested for the shell-side friction coefficient and the Nusselt numbers of non-Newtonian nanofluids and give very good agreement with experimental data.

A study of the effect of in-line and perpendicular magnetic fields on beam characteristics of electron guns in medical linear accelerators.

PubMed

Constantin, Dragoş E; Fahrig, Rebecca; Keall, Paul J

2011-07-01

Using magnetic resonance imaging (MRI) for real-time guidance during radiotherapy is an active area of research and development. One aspect of the problem is the influence of the MRI scanner, modeled here as an external magnetic field, on the medical linear accelerator (linac) components. The present work characterizes the behavior of two medical linac electron guns with external magnetic fields for in-line and perpendicular orientations of the linac with respect to the MRI scanner. Two electron guns, Litton L-2087 and Varian VTC6364, are considered as representative models for this study. Emphasis was placed on the in-line design approach in which case the MRI scanner and the linac axes of symmetry coincide and assumes no magnetic shielding of the linac. For the in-line case, the magnetic field from a 0.5 T open MRI (GE Signa SP) magnet with a 60 cm gap between its poles was computed and used in full three dimensional (3D) space charge simulations, whereas for the perpendicular case the magnetic field was constant. For the in-line configuration, it is shown that the electron beam is not deflected from the axis of symmetry of the gun and the primary beam current does not vanish even at very high values of the magnetic field, e.g., 0.16 T. As the field strength increases, the primary beam current has an initial plateau of constant value after which its value decreases to a minimum corresponding to a field strength of approximately 0.06 T. After the minimum is reached, the current starts to increase slowly. For the case when the beam current computation is performed at the beam waist position the initial plateau ends at 0.016 T for Litton L-2087 and at 0.012 T for Varian VTC6364. The minimum value of the primary beam current is 27.5% of the initial value for Litton L-2087 and 22.9% of the initial value for Varian VTC6364. The minimum current is reached at 0.06 and 0.062 T for Litton L-2087 and Varian VTC6364, respectively. At 0.16 T the beam current increases to 40.2 and 31.4% from the original value of the current for Litton L-2087 and Varian VTC6364, respectively. In contrast, for the case when the electron gun is perpendicular to the magnetic field, the electron beam is deflected from the axis of symmetry even at small values of the magnetic field. As the strength of the magnetic field increases, so does the beam deflection, leading to a sharp decrease of the primary beam current which vanishes at about 0.007 T for Litton L-2087 and at 0.006 T for Varian VTC6364, respectively. At zero external field, the beam rms emittance computed at beam waist is 1.54 and 1.29n-mm-mrad for Litton L-2087 and Varian VTC6364, respectively. For the inline configuration, there are two particular values of the external field where the beam rms emittance reaches a minimum. Litton L-2087 rms emittance reaches a minimum of 0.72n and 2.01 n-mm-mrad at 0.026 and 0.132 T, respectively. Varian VTC6364 rms emittance reaches a minimum of 0.34n and 0.35n-mm-mrad at 0.028 and 0.14 T, respectively. Beam radius dependence on the external field is shown for the in-line configuration for both electron guns. 3D space charge simulation of two electron guns, Litton L-2087 and Varian VTC6364, were performed for in-line and perpendicular external magnetic fields. A consistent behavior of Pierce guns in external magnetic fields was proven. For the in-line configuration, the primary beam current does not vanish but a large reduction of beam current (up to 77.1%) is observed at higher field strengths; the beam directionality remains unchanged. It was shown that for a perpendicular configuration the current vanishes due to beam bending under the action of the Lorentz force. For in-line configuration it was determined that the rms beam emittance reaches two minima for relatively high values of the external magnetic field.

A study of the effect of in-line and perpendicular magnetic fields on beam characteristics of electron guns in medical linear accelerators

PubMed Central

Constantin, Dragoş E.; Fahrig, Rebecca; Keall, Paul J.

2011-01-01

Purpose: Using magnetic resonance imaging (MRI) for real-time guidance during radiotherapy is an active area of research and development. One aspect of the problem is the influence of the MRI scanner, modeled here as an external magnetic field, on the medical linear accelerator (linac) components. The present work characterizes the behavior of two medical linac electron guns with external magnetic fields for in-line and perpendicular orientations of the linac with respect to the MRI scanner. Methods: Two electron guns, Litton L-2087 and Varian VTC6364, are considered as representative models for this study. Emphasis was placed on the in-line design approach in which case the MRI scanner and the linac axes of symmetry coincide and assumes no magnetic shielding of the linac. For the in-line case, the magnetic field from a 0.5 T open MRI (GE Signa SP) magnet with a 60 cm gap between its poles was computed and used in full three dimensional (3D) space charge simulations, whereas for the perpendicular case the magnetic field was constant. Results: For the in-line configuration, it is shown that the electron beam is not deflected from the axis of symmetry of the gun and the primary beam current does not vanish even at very high values of the magnetic field, e.g., 0.16 T. As the field strength increases, the primary beam current has an initial plateau of constant value after which its value decreases to a minimum corresponding to a field strength of approximately 0.06 T. After the minimum is reached, the current starts to increase slowly. For the case when the beam current computation is performed at the beam waist position the initial plateau ends at 0.016 T for Litton L-2087 and at 0.012 T for Varian VTC6364. The minimum value of the primary beam current is 27.5% of the initial value for Litton L-2087 and 22.9% of the initial value for Varian VTC6364. The minimum current is reached at 0.06 and 0.062 T for Litton L-2087 and Varian VTC6364, respectively. At 0.16 T the beam current increases to 40.2 and 31.4% from the original value of the current for Litton L-2087 and Varian VTC6364, respectively. In contrast, for the case when the electron gun is perpendicular to the magnetic field, the electron beam is deflected from the axis of symmetry even at small values of the magnetic field. As the strength of the magnetic field increases, so does the beam deflection, leading to a sharp decrease of the primary beam current which vanishes at about 0.007 T for Litton L-2087 and at 0.006 T for Varian VTC6364, respectively. At zero external field, the beam rms emittance computed at beam waist is 1.54 and 1.29π-mm-mrad for Litton L-2087 and Varian VTC6364, respectively. For the in-line configuration, there are two particular values of the external field where the beam rms emittance reaches a minimum. Litton L-2087 rms emittance reaches a minimum of 0.72π and 2.01π-mm-mrad at 0.026 and 0.132 T, respectively. Varian VTC6364 rms emittance reaches a minimum of 0.34π and 0.35π-mm-mrad at 0.028 and 0.14 T, respectively. Beam radius dependence on the external field is shown for the in-line configuration for both electron guns. Conclusions: 3D space charge simulation of two electron guns, Litton L-2087 and Varian VTC6364, were performed for in-line and perpendicular external magnetic fields. A consistent behavior of Pierce guns in external magnetic fields was proven. For the in-line configuration, the primary beam current does not vanish but a large reduction of beam current (up to 77.1%) is observed at higher field strengths; the beam directionality remains unchanged. It was shown that for a perpendicular configuration the current vanishes due to beam bending under the action of the Lorentz force. For in-line configuration it was determined that the rms beam emittance reaches two minima for relatively high values of the external magnetic field. PMID:21859019

In-line pressure within a HOTLINE® Fluid Warmer, under various flow conditions.

PubMed

Higashi, Midoriko; Yamaura, Ken; Matsubara, Yukie; Fukudome, Takuya; Hoka, Sumio

2015-04-01

Roller pump infusion devices are widely used for rapid infusion, and may be combined with separate warming devices. There may be instances however, where the pressures generated by the roller pump may not be compatible with the warming device. We assessed a commonly used roller pump in combination with a HOTLINE® Fluid Warmer, and found that it could generate pressures exceeding the HOTLINE® manufacturers specifications. This was of concern because the HOTLINE® manufacturer guideline states that not for use with pressure devices generating over 300 mmHg. Pressure greater than 300 mmHg may compromise the integrity of the HOTLINE® Fluid Warming Set. The aim of this study was to compare in-line pressure within a HOTLINE® Fluid Warmer at different infusion rates of a roller pump using various sizes of intravenous cannulae. The rapid infusion system comprised a 500 mL-normal saline bag, roller pump type infusion device, HOTLINE® Fluid Warmer (blood and fluid warmer system), and six different sizes of intravenous cannulae. In-line pressure was measured proximal to the HOTLINE® (pre-warmer) and proximal to the cannula (post-warmer), at flow rate of 50-160 mL/min. The in-line pressures increased significantly with increasing flow rate. The pre-warmer pressures exceeded 300 mmHg when the flow rate was ≥120 mL/min with 20-gauge, 48 mm length cannula, 130 with 20-gauge, 25 mm cannula, and 160 mL/min with 18-gauge, 48 mm cannula. However, they were <300 mmHg at any flow rates with 18-gauge, 30 mm cannula and 16-gauge cannulae. The post-warmer pressures exceeded 300 mmHg at the flow rate of 140 mL/min with 20-gauge, 48 mm cannula, and 160 mL/min with 20-gauge, 25 mm cannula, while they were <300 mmHg at any flow rates with 18 and 16-gauge cannulae. The in-line pressure within a HOTLINE® could exceed 300 mmHg, depending on the flow rate and size and length of cannula. It is important to pay attention to the size and length of cannulae and flow rate to keep the maximum in-line pressure<300 mmHg when a roller pump type infusion device is used.

Fire Protection Informational Exchange

DTIC Science & Technology

2016-07-01

0.95 L/min concurrent spray & 274x521 mm pool (66°C) i. Persistent fuels; turbine fuel in spray/pool; lubricant, hydraulic fluid in spray ii...conjugate image plane La Vision sCMOS + Kl long- distance microscope with CF4 objective wire .. " " " " ... in-line hologram image plane La...distance microscope with CF4 objective wire I phase disrurbanc.e (f= 2000 nun) .. " " " " ... in-line hologram image plane La Vision sCNlOS

Recycled poly(ethylene terephthalate) for direct food contact applications: challenge test of an inline recycling process.

PubMed

Franz, R; Welle, F

2002-05-01

Of all the plastics used for packaging, due to its low diffusivity and chemical inertness, poly(ethylene terephthalate) (PET) is one of the favoured candidate plastics for closed-loop recycling for new packaging applications. In the work reported here, a PET-recycling process was investigated with respect to its cleaning efficiency and compliance of the PET recyclate with food law. The key technology of the investigated PET-recycling process to remove contaminants consists of a predecontamination-extruder combination. At the end of the recycling process, there is either a pelletizing system or downstream equipment to produce preforms or flat sheets. Therefore, the process has two process options, an inline production of PET preforms and a batch option producing PET pellets. In the case of possible misuse of PET bottles by the consumer, the inline process produces higher concentrations in the bottle wall of the recyclate containing preforms. Owing to the dilution of the PET output material by large amounts of uncontaminated PET, the batch option is the less critical process in terms of consumer protection. Regarding an appropriate testing procedure for the evaluation of a bottle-to-bottle recycling process, both process options have their own specific requirements with respect to the design of a challenge test. A novel challenge test approach to the inline mode of a recycling process is presented here.

In-line optical fiber metallic mirror reflector for monolithic common path optical coherence tomography probes.

PubMed

Singh, Kanwarpal; Reddy, Rohith; Sharma, Gargi; Verma, Yogesh; Gardecki, Joseph A; Tearney, Guillermo

2018-03-01

Endoscopic optical coherence tomography probes suffer from various artifacts due to dispersion imbalance and polarization mismatch between reference and sample arm light. Such artifacts can be minimized using a common path approach. In this work, we demonstrate a miniaturized common path probe for optical coherence tomography using an inline fiber mirror. A common path optical fiber probe suitable for performing high-resolution endoscopic optical coherence tomography imaging was developed. To achieve common path functionality, an inline fiber mirror was fabricated using a thin gold layer. A commercially available swept source engine was used to test the designed probe in a cadaver human coronary artery ex vivo. We achieved a sensitivity of 104 dB for this probe using a swept source optical coherence tomography system. To test the probe, images of a cadaver human coronary artery were obtained, demonstrating the quality that is comparable to those obtained by OCT systems with separate reference arms. Additionally, we demonstrate recovery of ranging depth by use of a Michelson interferometer in the detection path. We developed a miniaturized monolithic inline fiber mirror-based common path probe for optical coherence tomography. Owing to its simplicity, our design will be helpful in endoscopic applications that require high-resolution probes in a compact form factor while reducing system complexity. Lasers Surg. Med. 50:230-235, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

SiGe HBT cryogenic preamplification for higher bandwidth donor spin read-out

NASA Astrophysics Data System (ADS)

Curry, Matthew; Carr, Stephen; Ten-Eyck, Greg; Wendt, Joel; Pluym, Tammy; Lilly, Michael; Carroll, Malcolm

2014-03-01

Single-shot read-out of a donor spin can be performed using the response of a single-electron-transistor (SET). This technique can produce relatively large changes in current, on the order of 1 (nA), to distinguish between the spin states. Despite the relatively large signal, the read-out time resolution has been limited to approximately 100 (kHz) of bandwidth because of noise. Cryogenic pre-amplification has been shown to extend the response of certain detection circuits to shorter time resolution and thus higher bandwidth. We examine a SiGe HBT circuit configuration for cryogenic preamplification, which has potential advantages over commonly used HEMT configurations. Here we present 4 (K) measurements of a circuit consisting of a Silicon-SET inline with a Heterojunction-Bipolar-Transistor (HBT). We compare the measured bandwidth with and without the HBT inline and find that at higher frequencies the signal-to-noise-ratio (SNR) with the HBT inline exceeds the SNR without the HBT inline. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE, Office of Basic Energy Sciences user facility. The work was supported by the Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

Sequential injection system with in-line solid phase extraction and soil mini-column for determination of zinc and copper in soil leachates.

PubMed

Paluch, Justyna; Mesquita, Raquel B R; Cerdà, Víctor; Kozak, Joanna; Wieczorek, Marcin; Rangel, António O S S

2018-08-01

A sequential injection (SI) system equipped with in-line solid phase extraction column and in-line soil mini-column is proposed for determination of zinc and copper in soil leachates. The spectrophotometric determination (560 nm) is based on the reaction of both analytes with 1-(2-Pyridylazo)-2-naphthol (PAN). Zinc is determined after retaining copper on a cationic resin (Chelex100) whereas copper is determined from the difference of the absorbance measured for both analytes, introduced into the system with the use of a different channel, and zinc absorbance. The influence of several potential interferences was studied. Using the developed method, zinc and copper were determined within the concentration ranges of 0.005-0.300 and 0.011-0.200 mg L -1 , and with a relative standard deviation lower than 6.0% and 5.1%, respectively. The detection limits are 1.4 and 3.0 µg/L for determination of zinc and copper, respectively. The developed SI method was verified by the determination of both analytes in synthetic and certified reference materials of water samples, and applied to the determination of the analytes in rain water and soil leachates from laboratory scale soil core column and in-line soil mini-column. Copyright © 2018 Elsevier B.V. All rights reserved.

A four-panel enclosure protects from explosion

NASA Technical Reports Server (NTRS)

King, P. V.

1972-01-01

Development of multi-layered baffle as enclosure to protect personnel from effects of explosion during production of ammunition is discussed. Advantages of new system over previous systems are described. Illustration of typical panel structure is provided.

UV water disinfector

DOEpatents

Gadgil, A.; Garud, V.

1998-07-14

A UV disinfector with a gravity driven feed water delivery system and an air-suspended bare UV lamp are disclosed. The disinfector is hydrodynamically optimized with a laminerizing, perforated baffle wall, beveled treatment chamber, and outlet weir. 7 figs.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oborn, B; Ge, Y; Hardcastle, N

Purpose: To report on significant dose enhancement effects caused by magnetic fields aligned parallel to 6MV photon beam radiotherapy of small lung tumors. Findings are applicable to future inline MRI-guided radiotherapy systems. Methods: 9 clinical lung plans were recalculated using Monte Carlo methods and external inline (parallel to the beam direction) magnetic fields of 0.5 T, 1.0 T and 3 T were included. Three plans were 6MV 3D-CRT and six were 6MV IMRT. The GTV’s ranged from 0.8 cc to 73 cc, while the PTV ranged from 1 cc to 180 cc. Results: The inline magnetic field has a moderatemore » impact in lung dose distributions by reducing the lateral scatter of secondary electrons and causing a small local dose increase. Superposition of multiple small beams acts to superimpose the small dose increases and can lead to significant dose enhancements, especially when the GTV is low density. Two plans with very small, low mean density GTV’s (<1 cc, ρ(mean)<0.35g/cc) showed uniform increases of 16% and 23% at 1 T throughout the PTV. Three plans with moderate mean density PTV’s (3–13 cc, ρ(mean)=0.58–0.67 g/cc) showed 6% mean dose enhancement at 1 T in the PTV, however not uniform throughout the GTV/PTV. Replanning would benefit these cases. The remaining 5 plans had large dense GTV’s (∼ 1 g/cc) and so only a minimal (<2%) enhancement was seen. In general the mean dose enhancement at 0.5 T was 60% less than 1 T, while 5–50% higher at 3 T. Conclusions: A paradigm shift in the efficacy of small lung tumor radiotherapy is predicted with future inline MRI-linac systems. This will be achieved by carefully taking advantage of the reduction of lateral electronic disequilibrium withing lung tissue that is induced naturally inside strong inline magnetic fields.« less

Graphene-based inline pressure sensor integrated with microfluidic elastic tube

NASA Astrophysics Data System (ADS)

Inoue, Nagisa; Onoe, Hiroaki

2018-01-01

We propose an inline pressure sensor composed of a polydimethylsiloxane (PDMS) microfluidic tube integrated with graphene sheets. The PDMS tube was fabricated through molding, and a multilayered graphene sheet was transferred on the surface of the PDMS tube. The pressure inside the tube was monitored using the changes in the electrical resistance of the transferred graphene. The proposed pressure sensor could be suitable for precise pressure measurement for a small amount of fluid in microfluidic systems including organ-on-a-chip devices.

Photo-fermentative hydrogen production in a 4m3 baffled reactor: Effects of hydraulic retention time.

PubMed

Zhang, Quanguo; Lu, Chaoyang; Lee, Duu-Jong; Lee, Yu-Jen; Zhang, Zhiping; Zhou, Xuehua; Hu, Jianjun; Wang, Yi; Jiang, Danping; He, Chao; Zhang, Tian

2017-09-01

A 4m 3 pilot-scale baffled continuous-flow photoreactor with four sequential chambers (#1-#4) was established and tested to evaluate its photo-fermentative hydrogen production from wastewater that contains (10g/L glucose using a functional consortium at 30°C, under light with an intensity of 3000±200lux with a hydraulic retention time (HRT) of 24-72h. The hydrogen production rate and the broth characteristics varied significantly in the flow direction. The hydrogen production rate was highest in chamber #1, and lower in chambers #2-#4 at an HRT of 72h, while the peak production rate shifted to the latter chambers as the HRT was shortened. The overall H 2 production rate increased as HRT decreased, but was not consistent with the predictions that were based on the complete-mixing assumption. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nitrogen removal in wood chip combined substrate baffled subsurface-flow constructed wetlands: impact of matrix arrangement and intermittent aeration.

PubMed

Li, Huai; Chi, Zifang; Yan, Baixing; Cheng, Long; Li, Jianzheng

2017-02-01

In this study, two lab-scale baffled subsurface-flow constructed wetlands (BSFCWs), including gravel-wood chips-slag and gravel-slag-wood chips, were operated at different intermittent aeration to evaluate the effect of artificial aeration and slow-released carbon source on the treatment efficiency of high-strength nitrogen wastewater. Results indicated that gravel-slag-wood chips extended aerobic/anaerobic alternating environment to gravel and slag zones and maintained anaerobic condition in the subsequent wood chip section. The order of gravel-slag-wood chip was more beneficial to pollutant removal. Sufficient carbon source supply resulted from wood-chip-framework substrate simultaneously obtained high removals of COD (97%), NH 4 + -N (95%), and TN (94%) in BSFCWs at 2 h aeration per day. The results suggest that intermittent aeration combined with wood chips could achieve high nitrogen removal in BSFCWs.

Laboratory evaluation of a reactive baffle approach to NOx control. Final technical report, February-April 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, S.G.; Van Stone, D.A.; Little, R.C.

1993-09-01

Vermiculite, vermiculite coated with magnesia, and activated carbon sorbents have successfully removed NOx (and carbon monoxide and particles) from combustion exhausts in a subscale drone jet engine test cell (JETC), but back pressure so generated elevated the temperature of the JETC and of the engine. The objective of this effort was to explore the feasibility of locating the sorbents in the face of the duct or of baffles parallel to the direction of flow within the ducts. Jet engine test cells (JETCs) are stationary sources of oxides of nitrogen (NOx), soot, and unburned or partially oxidized carbon compounds that formmore » as byproducts of imperfect combustion. Regulation of NOx emissions is being considered for implementation under the Clean Air Act Amendments of 1990. Several principles have been examined as candidate methods to control NOx emissions from JETCs.« less

Performance of an Anaerobic Baffled Reactor (ABR) in treatment of cassava wastewater

PubMed Central

Ferraz, Fernanda M.; Bruni, Aline T.; Del Bianchi, Vanildo L.

2009-01-01

The performance of an anaerobic baffled reactor (ABR) was evaluated in the treatment of cassava wastewater, a pollutant residue. An ABR divided in four equal volume compartments (total volume 4L) and operated at 35ºC was used in cassava wastewater treatment. Feed tank chemical oxygen demand (COD) was varied from 2000 to 7000 mg L-1 and it was evaluated the most appropriated hydraulic retention time (HRT) for the best performance on COD removal. The ABR was evaluated by analysis of COD (colorimetric method), pH, turbidity, total and volatile solids, alkalinity and acidity. Principal component analysis (PCA) was carried to better understand data obtained. The system showed buffering ability as acidity decreased along compartments while alkalinity and pH values were increased. There was particulate material retention and COD removal varied from 83 to 92% for HRT of 3.5 days. PMID:24031316

Baseline design and requirements for the LSST rotating enclosure (dome)

NASA Astrophysics Data System (ADS)

Neill, D. R.; DeVries, J.; Hileman, E.; Sebag, J.; Gressler, W.; Wiecha, O.; Andrew, J.; Schoening, W.

2014-07-01

The Large Synoptic Survey Telescope (LSST) is a large (8.4 meter) wide-field (3.5 degree) survey telescope, which will be located on the Cerro Pachón summit in Chile. As a result of the wide field of view, its optical system is unusually susceptible to stray light; consequently besides protecting the telescope from the environment the rotating enclosure (Dome) also provides indispensible light baffling. All dome vents are covered with light baffles which simultaneously provide both essential dome flushing and stray light attenuation. The wind screen also (and primarily) functions as a light screen providing only a minimum clear aperture. Since the dome must operate continuously, and the drives produce significant heat, they are located on the fixed lower enclosure to facilitate glycol water cooling. To accommodate day time thermal control, a duct system channels cooling air provided by the facility when the dome is in its parked position.

A Novel Compact Wideband TSA Array for Near-Surface Ice Sheet Penetrating Radar Applications

NASA Astrophysics Data System (ADS)

Zhang, Feng; Liu, Xiaojun; Fang, Guangyou

2014-03-01

A novel compact tapered slot antenna (TSA) array for near-surface ice sheet penetrating radar applications is presented. This TSA array is composed of eight compact antenna elements which are etched on two 480mm × 283mm FR4 substrates. Each antenna element is fed by a wideband coplanar waveguide (CPW) to coupled strip-line (CPS) balun. The two antenna substrates are connected together with a metallic baffle. To obtain wideband properties, another two metallic baffles are used along broadsides of the array. This array is fed by a 1 × 8 wideband power divider. The measured S11 of the array is less than -10dB in the band of 500MHz-2GHz, and the measured gain is more than 6dBi in the whole band which agrees well with the simulated results.

Low gravity reorientation in a scale-model Centaur liquid-hydrogen tank

NASA Technical Reports Server (NTRS)

Salzman, J. A.; Masica, W. J.; Lacovic, R. F.

1973-01-01

An experiment was conducted to investigate the process of liquid reorientation from one end of a scale-model Centaur liquid-hydrogen tank to the other end by means of low-level accelerations. Prior to reorientation, the liquid was stabilized at the top of the tank at a Bond number of 15. Tanks both with and without ring baffles and with tank radii of 5.5 and 7.0 centimeters were used in the study. Reorientation acceleration values were varied to obtain Bond numbers of 200 and 450. Liquid fill levels of 20 and 70 percent were used. From the data in this study, relations were developed to estimate reorientation event times in unbaffled tanks through the point of final liquid clearing from the top of the tank. The insertion of ring baffles drastically changed the reorientation flow profiles but resulted in only minor differences in the times of tank-top uncovering and liquid collection.

Experimental, Numerical, and Analytical Slosh Dynamics of Water and Liquid Nitrogen in a Spherical Tank

NASA Technical Reports Server (NTRS)

Storey, Jedediah Morse

2016-01-01

Understanding, predicting, and controlling fluid slosh dynamics is critical to safety and improving performance of space missions when a significant percentage of the spacecraft's mass is a liquid. Computational fluid dynamics simulations can be used to predict the dynamics of slosh, but these programs require extensive validation. Many experimental and numerical studies of water slosh have been conducted. However, slosh data for cryogenic liquids is lacking. Water and cryogenic liquid nitrogen are used in various ground-based tests with a spherical tank to characterize damping, slosh mode frequencies, and slosh forces. A single ring baffle is installed in the tank for some of the tests. Analytical models for slosh modes, slosh forces, and baffle damping are constructed based on prior work. Select experiments are simulated using a commercial CFD software, and the numerical results are compared to the analytical and experimental results for the purposes of validation and methodology-improvement.

Multi-phased anaerobic baffled reactor treating food waste.

PubMed

Ahamed, A; Chen, C-L; Rajagopal, R; Wu, D; Mao, Y; Ho, I J R; Lim, J W; Wang, J-Y

2015-04-01

This study was conducted to identify the performance of a multi-phased anaerobic baffled reactor (MP-ABR) with food waste (FW) as the substrate for biogas production and thereby to promote an efficient energy recovery and treatment method for the wastes with high organic solid content through phase separation. A four-chambered ABR was operated at an HRT of 30 days with an OLR of 0.5-1.0 g-VS/Ld for a period of 175 days at 35 ± 1°C. Consistent overall removal efficiencies of 85.3% (CODt), 94.5% (CODs), 89.6% (VFA) and 86.4% (VS) were observed throughout the experiment displaying a great potential to treat FW. Biogas generated was 215.57 mL/g-VS removed d. Phase separation was observed and supported by the COD and VFA trends, and an efficient recovery of bioenergy from FW was achieved. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Mechanistic Study of Nucleate Boiling Under Microgravity Conditions

NASA Technical Reports Server (NTRS)

Dhir, V. K.; Warrier, G. R.; Hasan, M. M.

2002-01-01

The overall objective of this work is to study nucleate boiling heat transfer under microgravity conditions in such a way that while providing basic knowledge of the phenomena, it also leads to development of simulation models and correlations that can be used as design tools for a wide range of gravity levels. In the study a building block type of approach is used and both pool and low velocity flow boiling are investigated. Starting with experiments using a single bubble, the complexity of the experiments is increased to two or three inline bubbles, to five bubbles placed on a two-dimensional grid. Finally, experiments are conducted where a large number of prescribed cavities nucleate on the heater and when a commercial surface is used. So far experiments have been conducted at earth normal gravity and in the reduced gravity environment of the KC-135 aircraft whereas experiments on the space station are planned. Modeling/complete numerical simulation of the boiling process is an integral part of the total effort. Experiments conducted with single bubbles formed on a nucleation site microfabricated on a polished silicon wafer show that for gravity levels (g) varying from 1.5g(sub e) to 0.01g(sub e), the bubble diameter at departure varies approximately as (g(sub e)/g)(exp 1/2) and the growth period as (g(sub e)/g). When bubbles merge either inline or in a plane, the bubble diameter at departure is found to be smaller than that obtained for a single bubble and shows a weaker dependence on the level of gravity. The possible reason is that as the bubbles merge they create fluid circulation around the bubbles, which in turn induces a lift force that is responsible for the earlier departure of the bubbles. The verification of this proposition is being sought through numerical simulations. There is a merger of two inline, three inline, and several bubbles in a plane in the low gravity environment of the KC-135 aircraft. After merger and before departure, a mushroom type of bubble with several stems attached to the heater surface is clearly evident. Local heat fluxes during growth and departure of a single bubble were also measured. It was found that during most of the growth period of the bubble, generally the wall heat flux decreased with time because of the increased dry area under the bubble. However, the heat flux increased rapidly just prior to departure of the bubble because of the transient conduction into the cold liquid rushing to fill the space vacated by the bubble as the bubble base shrinks. The measured heat fluxes at various radial locations are found to be in qualitative agreement with the numerical predictions. Single bubble studies at earth normal gravity have also been performed on surfaces oriented at different angles to the gravitational acceleration with flow parallel to the surface. It is found that in all cases the bubbles slide along the surface before lift-off from the surface. The lift force generated as a result of the relative motion between the sliding bubbles and the imposed flow is found to play an important role when the normal force due to buoyancy is reduced. An experimental apparatus for the study of the bubble behavior with imposed flow under reduced gravity conditions has been developed and will soon be employed for experiments in the KC-135 aircraft.

In-line characterization of nanostructured mass-produced polymer components using scatterometry

NASA Astrophysics Data System (ADS)

Skovlund Madsen, Jonas; Højlund Thamdrup, Lasse; Czolkos, Ilja; Hansen, Poul Erik; Johansson, Alicia; Garnaes, Jørgen; Nygård, Jesper; Hannibal Madsen, Morten

2017-08-01

Scatterometry is used as an in-line metrology solution for injection molded nanostructures to evaluate the pattern replication fidelity. The method is used to give direct feedback to an operator when testing new molding parameters and for continuous quality control. A compact scatterometer has been built and tested at a fabrication facility. The scatterometry measurements, including data analysis and handling of the samples, are much faster than the injection molding cycle time, and thus, characterization does not slow down the production rate. Fabrication and characterization of 160 plastic parts with line gratings are presented here, and the optimal molding temperatures for replication of nanostructures are found for two polymers. Scatterometry results are compared to state of the art metrology solutions: atomic force and scanning electron microscopy. It is demonstrated that the scatterometer can determine the structural parameters of the samples with an accuracy of a few nanometers in less than a second, thereby enabling in-line characterization.

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

In-line calibration of Raman systems for analysis of gas mixtures of hydrogen isotopologues with sub-percent accuracy.

PubMed

Schlösser, Magnus; Seitz, Hendrik; Rupp, Simone; Herwig, Philipp; Alecu, Catalin Gabriel; Sturm, Michael; Bornschein, Beate

2013-03-05

Highly accurate, in-line, and real-time composition measurements of gases are mandatory in many processing applications. The quantitative analysis of mixtures of hydrogen isotopologues (H2, D2, T2, HD, HT, and DT) is of high importance in such fields as DT fusion, neutrino mass measurements using tritium β-decay or photonuclear experiments where HD targets are used. Raman spectroscopy is a favorable method for these tasks. In this publication we present a method for the in-line calibration of Raman systems for the nonradioactive hydrogen isotopologues. It is based on precise volumetric gas mixing of the homonuclear species H2/D2 and a controlled catalytic production of the heteronuclear species HD. Systematic effects like spurious exchange reactions with wall materials and others are considered with care during the procedure. A detailed discussion of statistical and systematic uncertainties is presented which finally yields a calibration accuracy of better than 0.4%.

Science teachers' interpretations of Islamic culture related to science education versus the Islamic epistemology and ontology of science

NASA Astrophysics Data System (ADS)

Mansour, Nasser

2010-03-01

The debate about Islam and science extends to a debate about the relationship between Islam and science education. In this paper, I explore Egyptian teachers' views of the relationship between science and religion within the Islamic context. Teachers' key vision of the relationship between science and religion was that "religion comes first and science comes next. I will argue that teachers' personal religious beliefs are among the major constructs that drive teachers' ways of thinking and interpretation of scientific issues related with religion. Then, I discuss how teachers' personal religious beliefs have been formed and influenced their pedagogical beliefs related to science and religion issues. Finally, I will argue, how we use the personal religious beliefs model as a framework of teaching/learning scientific issues related with religion within sociocultural (Islamic) context. [InlineMediaObject not available: see fulltext.][InlineMediaObject not available: see fulltext.][InlineMediaObject not available: see fulltext.

Two- and Three-Dimensional Numerical Experiments Representing Two Limiting Cases of an In-Line Pair of Finger Seal Components

NASA Technical Reports Server (NTRS)

Braun, M. J.; Steinetz, B. M.; Kudriavtsev, V. V.; Proctor, M. P.; Kiraly, L. James (Technical Monitor)

2002-01-01

The work presented here concerns the numerical development and simulation of the flow, pressure patterns and motion of a pair of fingers arranged behind each other and axially aligned in-line. The fingers represent the basic elemental component of a Finger Seal (FS) and form a tight seal around the rotor. Yet their flexibility allows compliance with rotor motion and in a passive-adaptive mode complies also with the hydrodynamic forces induced by the flowing fluid. While the paper does not treat the actual staggered configuration of a finger seal, the inline arrangement represents a first step towards that final goal. The numerical 2-D (axial-radial) and 3-D results presented herein were obtained using a commercial package (CFD-ACE+). Both models use an integrated numerical approach, which couples the hydrodynamic fluid model (Navier-Stokes based) to the solid mechanics code that models the compliance of the fingers.

Raman spectroscopy for in-line water quality monitoring--instrumentation and potential.

PubMed

Li, Zhiyun; Deen, M Jamal; Kumar, Shiva; Selvaganapathy, P Ravi

2014-09-16

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.