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Sample records for krimipnevik wall streetil

  1. Wall turbulence without walls

    NASA Astrophysics Data System (ADS)

    Mizuno, Yoshinori; Jimenez, Javier

    2008-11-01

    Direct numerical simulations are presented of isolated logarithmic layers without an underlying buffer zone. They are implemented by enforcing artificial boundary conditions within the logarithmic layer which are synthesized from values from the interior of the flow. As an example, simulations of a half-channel employing this technique are discussed. The results exhibit logarithmic mean velocity profiles, and velocity fluctuation intensities that are similar to those obtained by the full DNS of half or full channels. Those results strongly suggest that the formation of a logarithmic layer is not overly dependent on the presence of a near-wall region, and that such a flow can exist by itself. The technique enables us to perform conceptual experiments to clarify what is essential to the logarithmic layer. For example, preliminary results show that the logarithmic layer cannot be created only by a non-uniform shear, and requires a spatial gradient of the scales of the fluctuations. Somewhat surprisingly, some simulations result in Kármán constants fairly different from κ=0.4, providing clues to what determines κ in real wall turbulence.

  2. Wonderful Walls

    ERIC Educational Resources Information Center

    Greenman, Jim

    2006-01-01

    In this article, the author emphasizes the importance of "working" walls in children's programs. Children's programs need "working" walls (and ceilings and floors) which can be put to use for communication, display, storage, and activity space. The furnishings also work, or don't work, for the program in another sense: in aggregate, they serve as…

  3. Wall Turbulence.

    ERIC Educational Resources Information Center

    Hanratty, Thomas J.

    1980-01-01

    This paper gives an account of research on the structure of turbulence close to a solid boundary. Included is a method to study the flow close to the wall of a pipe without interferring with it. (Author/JN)

  4. 'Stucco' Walls

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This projected mosaic image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial clotting or cement-like properties of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) wide and 5 centimeters (2 inches) tall.(This image also appears as an inset on a separate image from the rover's navigation camera, showing the location of this particular spot within the trench wall.)

  5. 'Stucco' Walls

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This projected mosaic image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial clotting or cement-like properties of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) wide and 5 centimeters (2 inches) tall.(This image also appears as an inset on a separate image from the rover's navigation camera, showing the location of this particular spot within the trench wall.)

  6. Wall Art

    ERIC Educational Resources Information Center

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  7. Wall Art

    ERIC Educational Resources Information Center

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  8. Wall Covering

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The attractive wall covering shown below is one of 132 styles in the Mirror Magic II line offered by The General Tire & Rubber Company, Akron, Ohio. The material is metallized plastic fabric, a spinoff from space programs. Wall coverings are one of many consumer applications of aluminized plastic film technology developed for NASA by a firm later bought by King-Seeley Thermos Company, Winchester, Massachusetts, which now produces the material. The original NASA use was in the Echo 1 passive communications satellite, a "space baloon" made of aluminized mylar; the high reflectivity of the metallized coating enabled relay of communications signals from one Earth station to another by "bouncing" them off the satellite. The reflectivity feature also made the material an extremely efficient insulator and it was subsequently widely used in the Apollo program for such purposes as temperature control of spacecraft components and insulation of tanks for fuels that must be maintained at very low temperatures. I Used as a wall covering, the aluminized material offers extra insulation, reflects light and I resists cracking. In addition to General Tire, King-Seeley also supplies wall covering material to Columbus Coated Fabrics Division of Borden, Incorporated, Columbus, Ohio, among others.

  9. Wall Turbulence

    DTIC Science & Technology

    1992-04-01

    Doppler velocimeter, computer experiments, and pulsed-laser velocimetry. External influences to be studied are imposed flow oscillations , wavy walls...imposed flow oscillations Studies of the effect of imposed small amplitude flow oscillations have shown no effect on the time mean flow. Work was...undertaken to see if imposed large amplitude oscillations can affect drag. The system used was water flow through a two inch pipe. The flow oscillations

  10. Cooling wall

    SciTech Connect

    Nosenko, V.I.

    1995-07-01

    Protecting the shells of blast furnaces is being resolved by installing cast iron cooling plates. The cooling plates become non-operational in three to five years. The problem is that defects occur in manufacturing the cooling plates. With increased volume and intensity of work placed on blast furnaces, heat on the cast iron cooling plates reduces their reliability that limits the interim repair period of blast furnaces. Scientists and engineers from the Ukraine studied this problem for several years, developing a new method of cooling the blast furnace shaft called the cooling wall. Traditional cast iron plates were replaced by a screen of steel tubes, with the area between the tubes filled with fireproof concrete. Before placing the newly developed furnace shaft into operation, considerable work was completed such as theoretical calculations, design, research of temperature fields and tension. Continual testing over many years confirms the value of this research in operating blast furnaces. The cooling wall works with water cooling as well as vapor cooling and is operating in 14 blast furnaces in the Ukraine and two in Russia, and has operated for as long as 14 years.

  11. Wall to Wall Optimal Transport

    NASA Astrophysics Data System (ADS)

    Chini, Gregory P.; Hassanzadeh, Pedram; Doering, Charles R.

    2013-11-01

    How much heat can be transported between impermeable fixed-temperature walls by incompressible flows with a given amount of kinetic energy or enstrophy? What do the optimal velocity fields look like? We employ variational calculus to address these questions in the context of steady 2D flows. The resulting nonlinear Euler-Lagrange equations are solved numerically, and in some cases analytically, to find the maximum possible Nusselt number Nu as a function of the Péclect number Pe , a measure of the flow's energy or enstrophy. We find that in the fixed-energy problem Nu ~ Pe , while in the fixed-enstrophy problem Nu ~ Pe 10 / 17 . In both cases, the optimal flow consists of an array of convection cells with aspect ratio Γ (Pe) . Interpreting our results in terms of the Rayleigh number Ra for relevant buoyancy-driven problems, we find Nu <= 1 + 0 . 035 Ra and Γ ~ Ra - 1 / 2 for porous medium convection (which occurs with fixed energy), and Nu <= 1 + 0 . 115 Ra 5 / 12 and Γ ~ Ra - 1 / 4 for Rayleigh-Bénard convection (which occurs with fixed enstrophy and for free-slip walls). This work was supported by NSF awards PHY-0855335, DMS-0927587, and PHY-1205219 (CRD) and DMS-0928098 (GPC). Much of this work was completed at the 2012 Geophysical Fluid Dynamics (GFD) Program at Woods Hole Oceanographic Institution.

  12. Wall surveyor project report

    SciTech Connect

    Mullenhoff, D.J.; Johnston, B.C.; Azevedo, S.G.

    1996-02-22

    A report is made on the demonstration of a first-generation Wall Surveyor that is capable of surveying the interior and thickness of a stone, brick, or cement wall. LLNL`s Micropower Impulse Radar is used, based on emitting and detecting very low amplitude and short microwave impulses (MIR rangefinder). Six test walls were used. While the demonstrator MIR Wall Surveyor is not fieldable yet, it has successfully scanned the test walls and produced real-time images identifying the walls. It is planned to optimize and package the evaluation wall surveyor into a hand held unit.

  13. If walls could talk

    NASA Technical Reports Server (NTRS)

    Braam, J.; McIntire, L. V. (Principal Investigator)

    1999-01-01

    The plant cell wall is very complex, both in structure and function. The wall components and the mechanical properties of the wall have been implicated in conveying information that is important for morphogenesis. Proteoglycans, fragments of polysaccharides and the structural integrity of the wall may relay signals that influence cellular differentiation and growth control. Furthering our knowledge of cell wall structure and function is likely to have a profound impact on our understanding of how plant cells communicate with the extracellular environment.

  14. If walls could talk

    NASA Technical Reports Server (NTRS)

    Braam, J.; McIntire, L. V. (Principal Investigator)

    1999-01-01

    The plant cell wall is very complex, both in structure and function. The wall components and the mechanical properties of the wall have been implicated in conveying information that is important for morphogenesis. Proteoglycans, fragments of polysaccharides and the structural integrity of the wall may relay signals that influence cellular differentiation and growth control. Furthering our knowledge of cell wall structure and function is likely to have a profound impact on our understanding of how plant cells communicate with the extracellular environment.

  15. Halogenation of microcapsule walls

    NASA Technical Reports Server (NTRS)

    Davis, T. R.; Schaab, C. K.; Scott, J. C.

    1972-01-01

    Procedure for halogenation of confining walls of both gelatin and gelatin-phenolic resin capsules is similar to that used for microencapsulation. Ten percent halogen content renders capsule wall nonburning; any higher content enhances flame-retardant properties of selected internal phase material. Halogenation decreases permeability of wall material to encapsulated materials.

  16. The Lamportian cell wall

    SciTech Connect

    Keiliszewski, M.; Lamport, D. )

    1991-05-01

    The Lamportian Warp-Weft hypothesis suggests a cellulose-extensin interpenetrating network where extensin mechanically couples the load-bearing cellulose microfibrils in a wall matrix that is best described as a microcomposite. This model is based on data gathered from the extensin-rich walls of tomato and sycamore cell suspension culture, wherein extensin precursors are insolubilized into the wall by undefined crosslinks. The authors recent work with cell walls isolated from intact tissue as well as walls from suspension cultured cells of the graminaceous monocots maize and rice, the non-graminaceous monocot asparagus, the primitive herbaceous dicot sugar beet, and the gymnosperm Douglas Fir indicate that although extensins are ubiquitous to all plant species examined, they are not the major structural protein component of most walls examined. Amino acid analyses of intact and HF-treated walls shows a major component neither an HRGP, nor directly comparable to the glycine-rich wall proteins such as those associated with seed coat walls or the 67 mole% glycine-rich proteins cloned from petunia and soybean. Clearly, structural wall protein alternatives to extensin exist and any cell wall model must take that into account. If we assume that extracellular matrices are a priori network structures, then new Hypless' structural proteins in the maize cell wall raise questions about the sort of network these proteins create: the kinds of crosslinks involved; how they are formed; and the roles played by the small amounts of HRGPs.

  17. Great wall...and lesser wall

    NASA Astrophysics Data System (ADS)

    What nature has covered up, humans have again exposed. Using images from the Spaceborne Imaging Radar C/X-band Synthetic Aperture Radar (SIR-C/X-SAR), researchers have found remnants of two generations of the Great Wall of China buried beneath desert sands, 700 km west of Beijing. Erosion and wind storms had shielded parts of both walls from view, but the foundation now has been laid bare by remote sensors.

  18. Fluidized wall for protecting fusion chamber walls

    DOEpatents

    Maniscalco, James A.; Meier, Wayne R.

    1982-01-01

    Apparatus for protecting the inner wall of a fusion chamber from microexplosion debris, x-rays, neutrons, etc. produced by deuterium-tritium (DT) targets imploded within the fusion chamber. The apparatus utilizes a fluidized wall similar to a waterfall comprising liquid lithium or solid pellets of lithium-ceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.

  19. Wall contraction in Bloch wall films.

    NASA Technical Reports Server (NTRS)

    Bartran, D. S.; Bourne, H. C., Jr.

    1972-01-01

    The phenomenon of wall contraction characterized by a peak in the velocity-field relationship and a region of negative differential mobility is observed in uniaxial magnetic thin films of various magnetic properties by careful interrupted-pulse experiments. The observed results agree quite well with the theory for bulk samples when the extensive flux closure of thin film walls is accounted for by a suitable empirical scaling factor.

  20. Wall of fundamental constants

    SciTech Connect

    Olive, Keith A.; Peloso, Marco; Uzan, Jean-Philippe

    2011-02-15

    We consider the signatures of a domain wall produced in the spontaneous symmetry breaking involving a dilatonlike scalar field coupled to electromagnetism. Domains on either side of the wall exhibit slight differences in their respective values of the fine-structure constant, {alpha}. If such a wall is present within our Hubble volume, absorption spectra at large redshifts may or may not provide a variation in {alpha} relative to the terrestrial value, depending on our relative position with respect to the wall. This wall could resolve the contradiction between claims of a variation of {alpha} based on Keck/Hires data and of the constancy of {alpha} based on Very Large Telescope data. We derive the properties of the wall and the parameters of the underlying microscopic model required to reproduce the possible spatial variation of {alpha}. We discuss the constraints on the existence of the low-energy domain wall and describe its observational implications concerning the variation of the fundamental constants.

  1. Abdominal wall fat pad biopsy

    MedlinePlus

    Amyloidosis - abdominal wall fat pad biopsy; Abdominal wall biopsy; Biopsy - abdominal wall fat pad ... method of taking an abdominal wall fat pad biopsy . The health care provider cleans the skin on ...

  2. Liquid Wall Chambers

    SciTech Connect

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  3. A Generalized Wall Function

    NASA Technical Reports Server (NTRS)

    Shih, Tsan-Hsing; Povinelli, Louis A.; Liu, Nan-Suey; Potapczuk, Mark G.; Lumley, J. L.

    1999-01-01

    The asymptotic solutions, described by Tennekes and Lumley (1972), for surface flows in a channel, pipe or boundary layer at large Reynolds numbers are revisited. These solutions can be extended to more complex flows such as the flows with various pressure gradients, zero wall stress and rough surfaces, etc. In computational fluid dynamics (CFD), these solutions can be used as the boundary conditions to bridge the near-wall region of turbulent flows so that there is no need to have the fine grids near the wall unless the near-wall flow structures are required to resolve. These solutions are referred to as the wall functions. Furthermore, a generalized and unified law of the wall which is valid for whole surface layer (including viscous sublayer, buffer layer and inertial sublayer) is analytically constructed. The generalized law of the wall shows that the effect of both adverse and favorable pressure gradients on the surface flow is very significant. Such as unified wall function will be useful not only in deriving analytic expressions for surface flow properties but also bringing a great convenience for CFD methods to place accurate boundary conditions at any location away from the wall. The extended wall functions introduced in this paper can be used for complex flows with acceleration, deceleration, separation, recirculation and rough surfaces.

  4. Metallic Wall Hall Thrusters

    NASA Technical Reports Server (NTRS)

    Goebel, Dan Michael (Inventor); Hofer, Richard Robert (Inventor); Mikellides, Ioannis G. (Inventor)

    2016-01-01

    A Hall thruster apparatus having walls constructed from a conductive material, such as graphite, and having magnetic shielding of the walls from the ionized plasma has been demonstrated to operate with nearly the same efficiency as a conventional non-magnetically shielded design using insulators as wall components. The new design is believed to provide the potential of higher power and uniform operation over the operating life of a thruster device.

  5. Phantom domain walls

    NASA Astrophysics Data System (ADS)

    Avelino, P. P.; Ferreira, V. M. C.; Menezes, J.; Sousa, L.

    2017-08-01

    We consider a model with two real scalar fields which admits phantom domain wall solutions. We investigate the structure and evolution of these phantom domain walls in an expanding homogeneous and isotropic universe. In particular, we show that the increase of the tension of the domain walls with cosmic time, associated to the evolution of the phantom scalar field, is responsible for an additional damping term in their equations of motion. We describe the macroscopic dynamics of phantom domain walls, showing that extended phantom defects whose tension varies on a cosmological time scale cannot be the dark energy.

  6. Thin Wall Iron Castings

    SciTech Connect

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  7. Interactive Word Walls

    ERIC Educational Resources Information Center

    Jackson, Julie; Narvaez, Rose

    2013-01-01

    It is common to see word walls displaying the vocabulary that students have learned in class. Word walls serve as visual scaffolds and are a classroom strategy used to reinforce reading and language arts instruction. Research shows a strong relationship between student word knowledge and academic achievement (Stahl and Fairbanks 1986). As a…

  8. Wall Finishes; Carpentry: 901895.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The course outline is designed to provide instruction in selecting, preparing, and installing wall finishing materials. Prerequisites for the course include mastery of building construction plans, foundations and walls, and basic mathematics. Intended for use in grades 11 and 12, the course contains five blocks of study totaling 135 hours of…

  9. Wall Construction; Carpentry: 901892.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The curriculum guide outlines a course designed to provide instruction in floor and wall layout, and in the diverse methods and construction of walls. Upon completion of this course the students should have acquired a knowledge of construction plans and structural foundations in addition to a basic knowledge of mathematics. The course consists of…

  10. Domain wall filters

    SciTech Connect

    Baer, Oliver; Narayanan, Rajamani; Neuberger, Herbert; Witzel, Oliver

    2007-03-15

    We propose using the extra dimension separating the domain walls carrying lattice quarks of opposite handedness to gradually filter out the ultraviolet fluctuations of the gauge fields that are felt by the fermionic excitations living in the bulk. This generalization of the homogeneous domain wall construction has some theoretical features that seem nontrivial.

  11. 'Stucco' Walls-2

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial 'clodding' or cementation of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) across and makes up half of the projected 'Stucco Walls' image.

  12. Interactive Word Walls

    ERIC Educational Resources Information Center

    Jackson, Julie; Narvaez, Rose

    2013-01-01

    It is common to see word walls displaying the vocabulary that students have learned in class. Word walls serve as visual scaffolds and are a classroom strategy used to reinforce reading and language arts instruction. Research shows a strong relationship between student word knowledge and academic achievement (Stahl and Fairbanks 1986). As a…

  13. 22. SIDE WALL CONSTRUCTION, NORTH TRAINING WALL, LOOKING WEST FROM ...

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

    22. SIDE WALL CONSTRUCTION, NORTH TRAINING WALL, LOOKING WEST FROM THE SAME POINT AS VIEW NO. 21. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  14. MIR wall surveyor

    SciTech Connect

    Lehman, S K

    1998-08-01

    This report addresses the problem of determining the layer thickness of a wall probed with a monostatic, hand-held implementation of Lawrence Livermore National Laboratory's Micropower Impulse Radar (MIR). Our goal is to locate the layers of the wall, and measure its overall thickness. The physical constraints require the device to be held fixed or swept rapidly over the wall. Thus an insufficient amount of backscattered data are collected to use diffraction tomographic [3] techniques to form images. The problem is therefore one of determining the wall layers from a set of time series reflection data. We develop two channel signal processing algorithms to determine the location of the layers of a wall, using as inputs the time series returned from the wall and the incident pulse. We study the problem using a finite difference time domain (FDTD) computer code to simulate the electromagnetic propagation within and scattering from a wall probed with five pulses. We use the results to develop and test signal processing procedures for locating the individual layers. We study two classes of algorithms: a deconvolution approach to determine a layered impulse response, and a correlation approach. After testing the algorithms on the FDTD results, we down-select to a suitable method.

  15. Wall conditioning on ITER

    NASA Astrophysics Data System (ADS)

    Shimada, Michiya; Pitts, Richard A.

    2011-08-01

    Like all tokamaks, ITER will require wall conditioning systems and strategies for successful operation from the point of view of plasma-facing surface preparation. Unlike today's devices however, ITER will have to manage large quantities of tritium fuel, imposing on wall conditioning a major responsibility for tritium inventory control. It will also feature the largest plasma-facing beryllium surface ever used in a tokamak and its high duty cycle and long pulse are expected to lead to the rapid formation of deposited layers in which tritium can accumulate. This paper summarises the currently planned ITER wall conditioning systems and describes the strategy for their use throughout exploitation of the device.

  16. Abdominal wall endometriomas.

    PubMed

    Chang, Yu; Tsai, Eing Mei; Long, Cheng Yu; Chen, Yung Hung; Kay, Nari

    2009-03-01

    Abdominal wall endometriosis is rare, with an incidence of 0.03-0.47% following cesarean delivery. The study reviewed abdominal wall endometriomas during an 8-year period in the Department of Obstetrics and Gynecology of the Kaohsiung Municipal Hsiao-Kang Hospital. Of 166 patients with endometriosis treated surgically in the hospital during an 8-year period, 20 (12%) had abdominal wall endometriomas. The mean interval between the prior operation and the appearance of the first symptoms was 39.3 months. Preoperative diagnosis was correct in 14 patients (70%). Abdominal wall endometrioma is more common than generally assumed in patients visiting the hospital. In patients with a palpable subcutaneous mass near surgical scars associated with cyclic or constant pain, a thorough history and physical examination are sufficient to establish the presence of endometriomas. A surgical-wide excision with clear margins is the single treatment of choice.

  17. [Nursing care wall planning].

    PubMed

    Moreau, Véronique

    2013-01-01

    Nursing care wall planners are not a tool for assessing workload, but a means of providing coherence and individualised monitoring of care. Its application is focused not only on team organisation, but also on the patient's needs.

  18. Coke oven wall pressures

    SciTech Connect

    Not Available

    1990-01-01

    This book presents papers on coke oven wall pressures. Topics include How to Extend the Lifetime of Tall, High Performance Coke Ovens, Control of Operation and Equipment Prevents Coke Oven Damage, and Forensic Study of Fairfield Coke Battery 2.

  19. Plant cell walls.

    PubMed

    Höfte, Herman; Voxeur, Aline

    2017-09-11

    Plants are able to generate large leaf surfaces that act as two-dimensional solar panels with a minimum investment in building material, thanks to a hydrostatic skeleton. This requires high intracellular pressures (up to 1 MPa), which depend on the presence of strong cell walls. The walls of growing cells (also called primary walls), are remarkably able to reconcile extreme tensile strength (up to 100 MPa) with the extensibility necessary for growth. All walled organisms are confronted with this dilemma - the need to balance strength and extensibility - and bacteria, fungi and plants have evolved independent solutions to cope. In this Primer, we discuss how plant cells have solved this problem, allowing them to support often very large increases in volume and to develop a broad variety of shapes (Figure 1A,B,D). This shape variation reflects the targeted deposition of wall material combined with local variations in cell-wall extensibility, processes that remain incompletely understood. Once the cell has reached its final size, it can lay down secondary wall layers, the composition and architecture of which are optimized to exert specific functions in different cell types (Figure 1E-G). Such functions include: providing mechanical support, for instance, for fibre cells in tree trunks or grass internodes; impermeabilising and strengthening vascular tissue to resist the negative pressure of the transpiration stream; increasing the surface area of the plasma membrane to facilitate solute exchange between cells (Figure 1C); or allowing important elastic deformation, for instance, to support the opening and closing of stomates. Specialized secondary walls, such as those constituting seed mucilage, are stored in a dehydrated form in seedcoat epidermis cells and show rapid swelling upon hydration of the seed. Other walls, in particular in reserve tissues, can accommodate large amounts of storage polysaccharides, which can be easily mobilized as a carbon source. Here we

  20. Conducting Wall Hall Thrusters

    NASA Technical Reports Server (NTRS)

    Goebel, Dan M.; Hofer, Richard R.; Mikellides, Ioannis G.; Katz, Ira; Polk, James E.; Dotson, Brandon

    2013-01-01

    A unique configuration of the magnetic field near the wall of Hall thrusters, called Magnetic Shielding, has recently demonstrated the ability to significantly reduce the erosion of the boron nitride (BN) walls and extend the life of Hall thrusters by orders of magnitude. The ability of magnetic shielding to minimize interactions between the plasma and the discharge chamber walls has for the first time enabled the replacement of insulating walls with conducting materials without loss in thruster performance. The boron nitride rings in the 6 kW H6 Hall thruster were replaced with graphite that self-biased to near the anode potential. The thruster efficiency remained over 60% (within two percent of the baseline BN configuration) with a small decrease in thrust and increase in Isp typical of magnetically shielded Hall thrusters. The graphite wall temperatures decreased significantly compared to both shielded and unshielded BN configurations, leading to the potential for higher power operation. Eliminating ceramic walls makes it simpler and less expensive to fabricate a thruster to survive launch loads, and the graphite discharge chamber radiates more efficiently which increases the power capability of the thruster compared to conventional Hall thruster designs.

  1. Ultimate Cost of Building Walls.

    ERIC Educational Resources Information Center

    Grimm, Clayford T.; Gross, James G.

    The need for economic analysis of building walls is discussed, and the factors influencing the ultimate cost of exterior walls are studied. The present worth method is used to analyze three types of exterior non-loadbearing panel or curtain walls. Anticipated costs are expressed in terms of their present value per square foot of wall area. The…

  2. Electroweak bubble wall speed limit

    NASA Astrophysics Data System (ADS)

    Bödeker, Dietrich; Moore, Guy D.

    2017-05-01

    In extensions of the Standard Model with extra scalars, the electroweak phase transition can be very strong, and the bubble walls can be highly relativistic. We revisit our previous argument that electroweak bubble walls can "run away," that is, achieve extreme ultrarelativistic velocities γ ~ 1014. We show that, when particles cross the bubble wall, they can emit transition radiation. Wall-frame soft processes, though suppressed by a power of the coupling α, have a significance enhanced by the γ-factor of the wall, limiting wall velocities to γ ~ 1/α. Though the bubble walls can move at almost the speed of light, they carry an infinitesimal share of the plasma's energy.

  3. Personal Display Wall

    SciTech Connect

    Shalf, John; Bethel, E. Wes; Siegerist, Cristina

    2004-01-01

    The LBNL Visualization Group has created a tiled display wall design that uses components that are readily available from a local hardware store and/or multiple online vendors, and requires minimal tools and skill to assemble. The result is a low-cost, easy to assemble tiled display device that is readily accessible to visualization researchers and domain scientists alike. The LBNL Personal Display (PD) Wall differentiates itself from other LCD-matrix displays because its design minimizes cost and complexity while retaining the functionality of its more expensive tiled display brethren. The PD-Wall occupies the same amount of desktop area as a large flatscreen LCD display panel. LBNL will be publishing and distributing simple plans so that any laboratory or user site can construct their own copies of this device.

  4. Musculoskeletal chest wall pain

    PubMed Central

    Fam, Adel G.; Smythe, Hugh A.

    1985-01-01

    The musculoskeletal structures of the thoracic wall and the neck are a relatively common source of chest pain. Pain arising from these structures is often mistaken for angina pectoris, pleurisy or other serious disorders. In this article the clinical features, pathogenesis and management of the various musculoskeletal chest wall disorders are discussed. The more common causes are costochondritis, traumatic muscle pain, trauma to the chest wall, “fibrositis” syndrome, referred pain, psychogenic regional pain syndrome, and arthritis involving articulations of the sternum, ribs and thoracic spine. Careful analysis of the history, physical findings and results of investigation is essential for precise diagnosis and effective treatment. ImagesFig. 3Fig. 4Fig. 5 PMID:4027804

  5. Thermal treatment wall

    DOEpatents

    Aines, Roger D.; Newmark, Robin L.; Knauss, Kevin G.

    2000-01-01

    A thermal treatment wall emplaced to perform in-situ destruction of contaminants in groundwater. Thermal destruction of specific contaminants occurs by hydrous pyrolysis/oxidation at temperatures achievable by existing thermal remediation techniques (electrical heating or steam injection) in the presence of oxygen or soil mineral oxidants, such as MnO.sub.2. The thermal treatment wall can be installed in a variety of configurations depending on the specific objectives, and can be used for groundwater cleanup, wherein in-situ destruction of contaminants is carried out rather than extracting contaminated fluids to the surface, where they are to be cleaned. In addition, the thermal treatment wall can be used for both plume interdiction and near-wellhead in-situ groundwater treatment. Thus, this technique can be utilized for a variety of groundwater contamination problems.

  6. Mouse bladder wall injection.

    PubMed

    Fu, Chi-Ling; Apelo, Charity A; Torres, Baldemar; Thai, Kim H; Hsieh, Michael H

    2011-07-12

    Mouse bladder wall injection is a useful technique to orthotopically study bladder phenomena, including stem cell, smooth muscle, and cancer biology. Before starting injections, the surgical area must be cleaned with soap and water and antiseptic solution. Surgical equipment must be sterilized before use and between each animal. Each mouse is placed under inhaled isoflurane anesthesia (2-5% for induction, 1-3% for maintenance) and its bladder exposed by making a midline abdominal incision with scissors. If the bladder is full, it is partially decompressed by gentle squeezing between two fingers. The cell suspension of interest is intramurally injected into the wall of the bladder dome using a 29 or 30 gauge needle and 1 cc or smaller syringe. The wound is then closed using wound clips and the mouse allowed to recover on a warming pad. Bladder wall injection is a delicate microsurgical technique that can be mastered with practice.

  7. Axion domain wall baryogenesis

    SciTech Connect

    Daido, Ryuji; Kitajima, Naoya; Takahashi, Fuminobu

    2015-07-28

    We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, m≃10{sup 8}–10{sup 13} GeV and f≃10{sup 13}–10{sup 16} GeV. Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.

  8. Axion domain wall baryogenesis

    SciTech Connect

    Daido, Ryuji; Kitajima, Naoya; Takahashi, Fuminobu E-mail: kitajima@tuhep.phys.tohoku.ac.jp

    2015-07-01

    We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, m ≅ 10{sup 8}–10{sup 13} GeV and f ≅ 10{sup 13}–10{sup 16} GeV . Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.

  9. Gullies in Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-388, 11 June 2003

    Many craters and troughs at polar and middle latitudes on Mars have gullies carved in their walls. These gullies may have formed by running water; others have suggested alternative, exotic fluids such as liquid or gaseous carbon dioxide. This view of martian gullies was acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC). The image shows gullies in the wall of an old meteor impact crater near 39.0oS, 200.7oW. Sunlight illuminates the scene from the upper left.

  10. Gullied Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-371, 25 May 2003

    Gullies are common in some regions on middle- and polar-latitude slopes, such as crater walls. This March 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies on the north wall of a crater in the Atlantis Chaos region near 34.3oS, 178.0oW. The gullies might have formed by flow of a fluid--perhaps liquid water--sometime in the geologically recent martian past. Sunlight illuminates the scene from the upper left.

  11. Chest Wall Trauma.

    PubMed

    Majercik, Sarah; Pieracci, Fredric M

    2017-05-01

    Chest wall trauma is common, and contributes significantly to morbidity and mortality of trauma patients. Early identification of major chest wall and concomitant intrathoracic injuries is critical. Generalized management of multiple rib fractures and flail chest consists of adequate pain control (including locoregional modalities); management of pulmonary dysfunction by invasive and noninvasive means; and, in some cases, surgical fixation. Multiple studies have shown that patients with flail chest have substantial benefit (decreased ventilator and intensive care unit days, improved pulmonary function, and improved long-term functional outcome) when they undergo surgery compared with nonoperative management. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Gullies in Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-388, 11 June 2003

    Many craters and troughs at polar and middle latitudes on Mars have gullies carved in their walls. These gullies may have formed by running water; others have suggested alternative, exotic fluids such as liquid or gaseous carbon dioxide. This view of martian gullies was acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC). The image shows gullies in the wall of an old meteor impact crater near 39.0oS, 200.7oW. Sunlight illuminates the scene from the upper left.

  13. Gullied Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-371, 25 May 2003

    Gullies are common in some regions on middle- and polar-latitude slopes, such as crater walls. This March 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies on the north wall of a crater in the Atlantis Chaos region near 34.3oS, 178.0oW. The gullies might have formed by flow of a fluid--perhaps liquid water--sometime in the geologically recent martian past. Sunlight illuminates the scene from the upper left.

  14. Runaway dilatonic domain walls

    SciTech Connect

    Aguirre, Anthony; Johnson, Matthew C.; Larfors, Magdalena

    2010-02-15

    We explore the stability of domain wall and bubble solutions in theories with compact extra dimensions. The energy density stored inside of the wall can destabilize the volume modulus of a compactification, leading to solutions containing either a timelike singularity or a region where space decompactifies, depending on the metric ansatz. We determine the structure of such solutions both analytically and using numerical simulations, and analyze how they arise in compactifications of Einstein-Maxwell theory and type IIB string theory. The existence of instabilities has important implications for the formation of networks of topological defects and the population of vacua during eternal inflation.

  15. Cell wall chemistry

    Treesearch

    Roger M. Rowell; Roger Pettersen; James S. Han; Jeffrey S. Rowell; Mandla A. Tshabalala

    2005-01-01

    In chemical terms, wood is best defined as a three-dimensional biopolymer composite composed of an interconnected network of cellulose, hemicelluloses, and lignin with minor amounts of extractives and inorganics. The major chemical component of a living tree is water, but on a dryweight basis, all wood cell walls consist mainly of sugar-based polymers (carbohydrates,...

  16. Fly on the Wall

    ERIC Educational Resources Information Center

    Berry, Dave; Korpan, Cynthia

    2009-01-01

    This paper describes the implementation of a peer observation program at the University of Victoria called the Lecture Club. The observers are not interactive during the class--they are the proverbial flies on the wall. The paper identifies the program as self-developmental, discussing the attributes of this learning-to-teach and peer-sharing…

  17. A Wall of Faces

    ERIC Educational Resources Information Center

    Stevens, Lori

    2008-01-01

    Visitors to the campus of Orland High School (OHS) will never question that they have stepped into a world of the masses: kids, activity, personalities, busyness, and playfulness--a veritable cloud of mild bedlam. The wall of ceramic faces that greets a visitor in the school office is another reminder of the organized chaos that the teachers…

  18. A School without Walls.

    ERIC Educational Resources Information Center

    Venuti, Len Tai

    1994-01-01

    During the summer, selected students of Hawaiian ancestry who have completed seventh or eighth grade participate in a boarding program with outdoor activities such as pulling taro, star gazing, and camping. The activities eliminate walls of doubt and fear and nurture self-confidence, creativity, personal growth, leadership, and cultural awareness.…

  19. Pressure wall patch

    NASA Technical Reports Server (NTRS)

    Williamsen, Joel E. (Inventor); Weddendorf, Bruce C. (Inventor)

    1994-01-01

    A rigid patch body for placing over a damaged portion (hole) of an external wall of a pressurized vessel, such as a space vehicle or a habitat, is discussed. The rigid patch body allows an astronaut to make temporary repairs to the pressurized vessel from the exterior of the vessel, which enables more permanent repairs to be made from the interior of the vessel. The pressure wall patch of the present invention includes a floor surrounded by four side members. Each side member includes a threaded screw for anchoring the patch body to the external wall of the pressurized vessel and a recess in its lower surface for supporting an inflatable bladder for surrounding the damaged portion (hole) of the external wall to seal the area surrounding the damaged portion. This allows the vessel to be repressurized. The floor of the rigid patch body supports a source of gas that is connected to the gas supply valve and a gas supply gauge in communication with the gas supply valve and the inflatable bladder.

  20. A Wall of Faces

    ERIC Educational Resources Information Center

    Stevens, Lori

    2008-01-01

    Visitors to the campus of Orland High School (OHS) will never question that they have stepped into a world of the masses: kids, activity, personalities, busyness, and playfulness--a veritable cloud of mild bedlam. The wall of ceramic faces that greets a visitor in the school office is another reminder of the organized chaos that the teachers…

  1. Wall turbulence control

    NASA Technical Reports Server (NTRS)

    Wilkinson, Stephen P.; Lindemann, A. Margrethe; Beeler, George B.; Mcginley, Catherine B.; Goodman, Wesley L.; Balasubramanian, R.

    1986-01-01

    A variety of wall turbulence control devices which were experimentally investigated are discussed; these include devices for burst control, alteration of outer flow structures, large eddy substitution, increased heat transfer efficiency, and reduction of wall pressure fluctuations. Control of pre-burst flow was demonstrated with a single, traveling surface depression which is phase-locked to elements of the burst production process. Another approach to wall turbulence control is to interfere with the outer layer coherent structures. A device in the outer part of a boundary layer was shown to suppress turbulence and reduce drag by opposing both the mean and unsteady vorticity in the boundary layer. Large eddy substitution is a method in which streamline curvature is introduced into the boundary layer in the form of streamwise vortices. Riblets, which were already shown to reduce turbulent drag, were also shown to exhibit superior heat transfer characteristics. Heat transfer efficiency as measured by the Reynolds Analogy Factor was shown to be as much as 36 percent greater than a smooth flat plate in a turbulent boundary layer. Large Eddy Break-Up (LEBU) which are also known to reduce turbulent drag were shown to reduce turbulent wall pressure fluctuation.

  2. The Wall Coverings Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2012-01-01

    Students love nothing better than personalizing their space--desk, bedroom, or even their cars. This article describes a classroom challenge that gives students a chance to let their spirits soar with the invention of a new form of wall treatment. A trip to a big box store might prove to be most helpful for students to visualize their new product…

  3. The Wall Coverings Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2012-01-01

    Students love nothing better than personalizing their space--desk, bedroom, or even their cars. This article describes a classroom challenge that gives students a chance to let their spirits soar with the invention of a new form of wall treatment. A trip to a big box store might prove to be most helpful for students to visualize their new product…

  4. Lateral Abdominal Wall Reconstruction

    PubMed Central

    Baumann, Donald P.; Butler, Charles E.

    2012-01-01

    Lateral abdominal wall (LAW) defects can manifest as a flank hernias, myofascial laxity/bulges, or full-thickness defects. These defects are quite different from those in the anterior abdominal wall defects and the complexity and limited surgical options make repairing the LAW a challenge for the reconstructive surgeon. LAW reconstruction requires an understanding of the anatomy, physiologic forces, and the impact of deinnervation injury to design and perform successful reconstructions of hernia, bulge, and full-thickness defects. Reconstructive strategies must be tailored to address the inguinal ligament, retroperitoneum, chest wall, and diaphragm. Operative technique must focus on stabilization of the LAW to nonyielding points of fixation at the anatomic borders of the LAW far beyond the musculofascial borders of the defect itself. Thus, hernias, bulges, and full-thickness defects are approached in a similar fashion. Mesh reinforcement is uniformly required in lateral abdominal wall reconstruction. Inlay mesh placement with overlying myofascial coverage is preferred as a first-line option as is the case in anterior abdominal wall reconstruction. However, interposition bridging repairs are often performed as the surrounding myofascial tissue precludes a dual layered closure. The decision to place bioprosthetic or prosthetic mesh depends on surgeon preference, patient comorbidities, and clinical factors of the repair. Regardless of mesh type, the overlying soft tissue must provide stable cutaneous coverage and obliteration of dead space. In cases where the fasciocutaneous flaps surrounding the defect are inadequate for closure, regional pedicled flaps or free flaps are recruited to achieve stable soft tissue coverage. PMID:23372458

  5. Chronic Abdominal Wall Pain.

    PubMed

    Koop, Herbert; Koprdova, Simona; Schürmann, Christine

    2016-01-29

    Chronic abdominal wall pain is a poorly recognized clinical problem despite being an important element in the differential diagnosis of abdominal pain. This review is based on pertinent articles that were retrieved by a selective search in PubMed and EMBASE employing the terms "abdominal wall pain" and "cutaneous nerve entrapment syndrome," as well as on the authors' clinical experience. In 2% to 3% of patients with chronic abdominal pain, the pain arises from the abdominal wall; in patients with previously diagnosed chronic abdominal pain who have no demonstrable pathological abnormality, this likelihood can rise as high as 30% . There have only been a small number of clinical trials of treatment for this condition. The diagnosis is made on clinical grounds, with the aid of Carnett's test. The characteristic clinical feature is strictly localized pain in the anterior abdominal wall, which is often mischaracterized as a "functional" complaint. In one study, injection of local anesthesia combined with steroids into the painful area was found to relieve pain for 4 weeks in 95% of patients. The injection of lidocaine alone brought about improvement in 83-91% of patients. Long-term pain relief ensued after a single lidocaine injection in 20-30% of patients, after repeated injections in 40-50% , and after combined lidocaine and steroid injections in up to 80% . Pain that persists despite these treatments can be treated with surgery (neurectomy). Chronic abdominal wall pain is easily diagnosed on physical examination and can often be rapidly treated. Any physician treating patients with abdominal pain should be aware of this condition. Further comparative treatment trials will be needed before a validated treatment algorithm can be established.

  6. Moisture Research - Optimizing Wall Assemblies

    SciTech Connect

    Arena, Lois; Mantha, Pallavi

    2013-05-01

    In this project, the Consortium for Advanced Residential Buildings (CARB) team evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls. Wall assemblies evaluated included code minimum walls using spray foam insulation and fiberglass batts, high R-value walls at least 12 in. thick (R-40 and R-60 assemblies), and brick walls with interior insulation.

  7. 132. View of Great Wall of China retaining wall and ...

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

    132. View of Great Wall of China retaining wall and unnamed viaduct on Grandfather Mountain. Viaduct completed in 1987. Looking northwest. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  8. Typical Window, Interior Wall Paint Sequence, Wall Section, and Foundation ...

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

    Typical Window, Interior Wall Paint Sequence, Wall Section, and Foundation Sections - Civilian Conservation Corps (CCC) Camp NP-5-C, Barracks No. 5, CCC Camp Historic District at Chapin Mesa, Cortez, Montezuma County, CO

  9. 40. RETAINING WALL CONSTRUCTION SHOWING PORTION OF COMPLETED WALL. BACKFILLING ...

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

    40. RETAINING WALL CONSTRUCTION SHOWING PORTION OF COMPLETED WALL. BACKFILLING BY POWER SHOVEL IN PROGRESS. ZION NP NEGATIVE NO. 1490. PHOTOGRAPHER: PARKER, NO DATE - Zion-Mount Carmel Highway, Springdale, Washington County, UT

  10. DETAIL OF CROCKETT BARN WALL CONSTRUCTION, UPPER LEVEL. The wall ...

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

    DETAIL OF CROCKETT BARN WALL CONSTRUCTION, UPPER LEVEL. The wall construction of the Crockett barn includes a layer of diagonal sheathing that is exposed on the interior. - Crockett Farm, Barn, 1056 Fort Casey Road, Coupeville, Island County, WA

  11. Interior view of wall detail of southeast wall, view towards ...

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

    Interior view of wall detail of southeast wall, view towards the southeast, without scale - Fort McClellan Ammunition Storage Area, Building No. 4408, Second Avenue (Magazine Road), Anniston, Calhoun County, AL

  12. 4. CONSTRUCTION DETAIL, SW CORNER, SHOWING RETAINING WALL, BRIDGE WALL ...

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

    4. CONSTRUCTION DETAIL, SW CORNER, SHOWING RETAINING WALL, BRIDGE WALL AND EROSION ON ROAD SURFACE. - Bridalveil Fall Bridge No. 3, Spanning Bridalveil Creek on carriage road, Yosemite Village, Mariposa County, CA

  13. EAST WALL OF CRYSTALLIZER WING TO THE LEFT, END WALL ...

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

    EAST WALL OF CRYSTALLIZER WING TO THE LEFT, END WALL OF CRUSHING MILL IN CENTER. GABLE END OF BOILING HOUSE IN LEFT BACKGROUND. VIEW FROM THE SOUTH - Kekaha Sugar Company, Sugar Mill Building, 8315 Kekaha Road, Kekaha, Kauai County, HI

  14. Interior view of north wall of Chapel. The wall panel ...

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

    Interior view of north wall of Chapel. The wall panel is one of two carved with lists of those missing in nearby combat. - Flanders Field American Cemetery & Memorial, Chapel, Wortegemseweg 117, Waregem, West Flanders (Belgium)

  15. 1. SOUTHEAST REAR WALL AND NORTHEAST SIDE WALL OF CABINS ...

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

    1. SOUTHEAST REAR WALL AND NORTHEAST SIDE WALL OF CABINS FORGEMAN'S HOUSE NO. 1 AT RIGHT - Mount Etna Iron Works, Forgeman's House No. 1, Legislative Route 07020 between junctions of T.R. 461 & 463, Williamsburg, Blair County, PA

  16. Wind tunnels with adapted walls for reducing wall interference

    NASA Technical Reports Server (NTRS)

    Ganzer, U.

    1979-01-01

    The basic principle of adaptable wind tunnel walls is explained. First results of an investigation carried out at the Aero-Space Institute of Berlin Technical University are presented for two dimensional flexible walls and a NACA 0012 airfoil. With five examples exhibiting very different flow conditions it is demonstrated that it is possible to reduce wall interference and to avoid blockage at transonic speeds by wall adaptation.

  17. High-R Walls for Remodeling. Wall Cavity Moisture Monitoring

    SciTech Connect

    Wiehagen, J.; Kochkin, V.

    2012-12-01

    The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

  18. High-R Walls for Remodeling: Wall Cavity Moisture Monitoring

    SciTech Connect

    Wiehagen, J.; Kochkin, V.

    2012-12-01

    The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

  19. 25. NORTH TRAINING WALL, EAST SECTION, SIDE WALL CONSTRUCTION, LOOKING ...

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

    25. NORTH TRAINING WALL, EAST SECTION, SIDE WALL CONSTRUCTION, LOOKING WEST FROM A POINT ABOUT 500 FEET FROM THE MIDDLE HARBOR PARK FISHING PIER. (Panoramic view 1 of 2). - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  20. Great Wall of China

    NASA Image and Video Library

    2001-07-21

    This ASTER sub-image covers a 12 x 12 km area in northern Shanxi Province, China, and was acquired January 9, 2001. The low sun angle, and light snow cover highlight a section of the Great Wall, visible as a black line running diagonally through the image from lower left to upper right. The Great Wall is over 2000 years old and was built over a period of 1000 years. Stretching 4500 miles from Korea to the Gobi Desert it was first built to protect China from marauders from the north. This image is located at 40.2 degrees north latitude and 112.8 degrees east longitude. http://photojournal.jpl.nasa.gov/catalog/PIA02669

  1. DIELECTRIC WALL ACCELERATOR TECHNOLOGY

    SciTech Connect

    Sampayan, S; Caporaso, G; Chen, Y; Harris, J; Hawkins, S; Holmes, C; Nelson, S; Poole, B; Rhodes, M; Sanders, D; Sullivan, J; Wang, L; Watson, J

    2007-10-18

    The dielectric wall accelerator (DWA) is a compact pulsed power device where the pulse forming lines, switching, and vacuum wall are integrated into a single compact geometry. For this effort, we initiated a extensive compact pulsed power development program and have pursued the study of switching (gas, oil, laser induced surface flashover and photoconductive), dielectrics (ceramics and nanoparticle composites), pulse forming line topologies (asymmetric and symmetric Blumleins and zero integral pulse forming lines), and multilayered vacuum insulator (HGI) technology. Finally, we fabricated an accelerator cell for test on ETAII (a 5.5 MeV, 2 kA, 70 ns pulsewidth electron beam accelerator). We review our past results and report on the progress of accelerator cell testing.

  2. The Dielectric Wall Accelerator

    SciTech Connect

    Caporaso, George J.; Chen, Yu-Jiuan; Sampayan, Stephen E.

    2009-01-01

    The Dielectric Wall Accelerator (DWA), a class of induction accelerators, employs a novel insulating beam tube to impress a longitudinal electric field on a bunch of charged particles. The surface flashover characteristics of this tube may permit the attainment of accelerating gradients on the order of 100 MV/m for accelerating pulses on the order of a nanosecond in duration. A virtual traveling wave of excitation along the tube is produced at any desired speed by controlling the timing of pulse generating modules that supply a tangential electric field to the tube wall. Because of the ability to control the speed of this virtual wave, the accelerator is capable of handling any charge to mass ratio particle; hence it can be used for electrons, protons and any ion. The accelerator architectures, key technologies and development challenges will be described.

  3. Restrictive chest wall disorders.

    PubMed

    Donath, Joseph; Miller, Albert

    2009-06-01

    Hypoventilation can be caused by diseases of the chest wall. Any anatomical or functional abnormality of the bony thorax increases dead space ventilation and the work of breathing, whether congenital or acquired, acute or chronic, and whether its cause is infectious, traumatic, environmental, iatrogenic, or unknown. In this article, we discuss these heterogeneous disorders from the viewpoint of the practicing nonpediatric pulmonary physician, only briefly touching on surgical, pediatric, rheumatologic, and other nonpulmonary ramifications. Emphasis is on the most common and the best researched forms of chest wall restriction, including kyphoscoliosis, fibrothorax, thoracoplasty, flail chest, and ankylosing spondylitis. Other diseases such as osteoporosis with its less well known pulmonary effects, and some rarely seen entities, are briefly discussed.

  4. Bumper wall for plasma device

    DOEpatents

    Coultas, Thomas A.

    1977-01-01

    Operation of a plasma device such as a reactor for controlled thermonuclear fusion is facilitated by an improved bumper wall enclosing the plasma to smooth the flow of energy from the plasma as the energy impinges upon the bumper wall. The bumper wall is flexible to withstand unequal and severe thermal shocks and it is readily replaced at less expense than the cost of replacing structural material in the first wall and blanket that surround it.

  5. Molded Concrete Center Mine Wall

    NASA Technical Reports Server (NTRS)

    Lewis, E. V.

    1987-01-01

    Proposed semiautomatic system forms concrete-foam wall along middle of coal-mine passage. Wall helps support roof and divides passage into two conduits needed for ventilation of coal face. Mobile mold and concrete-foam generator form sections of wall in place.

  6. Curtain Wall Creates Ventilation Channel

    NASA Technical Reports Server (NTRS)

    Lewis, E. V.

    1985-01-01

    Curtain-wall structure proposed for removing methane and airborne coal dust from hydrojet-jaw mining machines. Channel between curtain wall and mine wall forms closed exhaust passage. Through it, gas and dust continuously removed so high concentrations of these explosive materials not build up.

  7. Molded Concrete Center Mine Wall

    NASA Technical Reports Server (NTRS)

    Lewis, E. V.

    1987-01-01

    Proposed semiautomatic system forms concrete-foam wall along middle of coal-mine passage. Wall helps support roof and divides passage into two conduits needed for ventilation of coal face. Mobile mold and concrete-foam generator form sections of wall in place.

  8. Curtain Wall Creates Ventilation Channel

    NASA Technical Reports Server (NTRS)

    Lewis, E. V.

    1985-01-01

    Curtain-wall structure proposed for removing methane and airborne coal dust from hydrojet-jaw mining machines. Channel between curtain wall and mine wall forms closed exhaust passage. Through it, gas and dust continuously removed so high concentrations of these explosive materials not build up.

  9. Left ventricular wall stress compendium.

    PubMed

    Zhong, L; Ghista, D N; Tan, R S

    2012-01-01

    Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models.

  10. Gullies in Crater Wall

    NASA Technical Reports Server (NTRS)

    2004-01-01

    6 April 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies in the wall of a large impact crater in Newton Basin near 41.9oS, 158.1oW. Such gullies may have formed by downslope movement of wet debris--i.e., water. Unfortunately, because the responsible fluid (if there was one) is no longer present today, only the geomorphology of the channels and debris aprons can be used to deduce that water might have been involved. The image covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left.

  11. The Chronicles Wall

    NASA Image and Video Library

    2017-05-03

    A brass plaque engraved with the name of Bruce Hall of CBS News is among the list of "The Chroniclers," a roll of honor on the wall at the NASA News Center at Kennedy Space Center in Florida. Hall, one of six new inductees in 2017, died after a lengthy illness on May 2, 2017. In this facility reporters from television, radio, print and online media outlets have monitored countless launches, landings and other space events in order to deliver the news to the world. The Chroniclers program recognizes retirees of the news and communications business who helped spread news of American space exploration from Kennedy Space Center for ten years or more.

  12. The Chronicles Wall

    NASA Image and Video Library

    2017-05-03

    Brass plaques engraved with the names of "The Chroniclers" adorn the wall at the NASA News Center at Kennedy Space Center in Florida. In the foreground are rows of stations where reporters from television, radio, print and online media outlets have monitored countless launches, landings and other space events in order to deliver the news to the world. The Chroniclers program recognizes retirees of the news and communications business who helped spread news of American space exploration from Kennedy Space Center for ten years or more.

  13. The Chronicles Wall

    NASA Image and Video Library

    2017-05-03

    Brass plaques engraved with the names of "The Chroniclers" create a roll of honor on the wall at the NASA News Center at Kennedy Space Center in Florida. In this facility reporters from television, radio, print and online media outlets have monitored countless launches, landings and other space events in order to deliver the news to the world. The Chroniclers program recognizes retirees of the news and communications business who helped spread news of American space exploration from Kennedy Space Center for ten years or more.

  14. The Chronicles Wall

    NASA Image and Video Library

    2017-05-03

    Brass plaques engraved with the names of Gatha Cottee of NASA Public Affairs, Walter Cronkite of CBS News and Bill Cummins of WEZY Radio are among the list of "The Chroniclers," a roll of honor on the wall at the NASA News Center at Kennedy Space Center in Florida. In this facility reporters from television, radio, print and online media outlets have monitored countless launches, landings and other space events in order to deliver the news to the world. The Chroniclers program recognizes retirees of the news and communications business who helped spread news of American space exploration from Kennedy Space Center for ten years or more.

  15. Gullies in Crater Wall

    NASA Technical Reports Server (NTRS)

    2004-01-01

    6 April 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies in the wall of a large impact crater in Newton Basin near 41.9oS, 158.1oW. Such gullies may have formed by downslope movement of wet debris--i.e., water. Unfortunately, because the responsible fluid (if there was one) is no longer present today, only the geomorphology of the channels and debris aprons can be used to deduce that water might have been involved. The image covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left.

  16. Structure of axionic domain walls

    NASA Astrophysics Data System (ADS)

    Huang, M. C.; Sikivie, P.

    1985-09-01

    The structure of axionic domain walls is investigated using the low-energy effective theory of axions and pions. We derive the spatial dependence of the phases of the Peccei-Quinn scalar field and the QCD quark-antiquark condensates inside an axionic domain wall. Thence an accurate estimate of the wall surface energy density is obtained. The equations of motion for axions, photons, leptons, and baryons in the neighborhood of axionic domain walls are written down and estimates are given for the wall reflection and transmission coefficients of these particles. Finally, we discuss the energy dissipation by axionic domain walls oscillating in the early universe due to the reflection of particles in the primordial soup.

  17. Baryogenesis from unstable domain walls

    NASA Astrophysics Data System (ADS)

    Ben-Menahem, Shahar; Cooper, Adrian R.

    1992-12-01

    There exists a class of cosmic strings that turn matter into antimatter (Alice strings). In a GUT where the unbroken gauge group contains charge conjugation (C), such strings form when a phase transition renders C a discrete symmetry. They become boundaries of domain walls at a later, C-breaking transition. These ``Alice walls'' are cosmologically harmless, but can play an important role in baryogenesis. We present a three-generation toy model with scalar baryons, where a quasi-static Alice wall (or a gas of such walls) temporarily gives rise to net baryogenesis of uniform sign everywhere in space. This becomes a permanent baryon excess if the wall shrinks away early enough. We comment on the possible relevance of a similar mechanism to baryogenesis in a realistic SO(10) unification model, where Alice walls would form at the scale of left-right symmetry breaking.

  18. Asymptotic dynamics of monopole walls

    NASA Astrophysics Data System (ADS)

    Cross, R.

    2015-08-01

    We determine the asymptotic dynamics of the U(N) doubly periodic BPS monopole in Yang-Mills-Higgs theory, called a monopole wall, by exploring its Higgs curve using the Newton polytope and amoeba. In particular, we show that the monopole wall splits into subwalls when any of its moduli become large. The long-distance gauge and Higgs field interactions of these subwalls are Abelian, allowing us to derive an asymptotic metric for the monopole wall moduli space.

  19. Flow tube wall regenerator performance

    NASA Astrophysics Data System (ADS)

    Decher, Reiner

    1990-07-01

    The performance of a regenerator processing a fluid in a reciprocating manner is described in terms of the fluid and the wall material characteristics as well as the geometry of the flow tubes through which the fluid is forced. It is shown that the effectiveness cannot exceed 50 percent and that it requires a wall material of low thermal heat capacity with good thermal contact between wall and fluid. Quantitative results are presented for a representative analysis model.

  20. Compound Walls For Vacuum Chambers

    NASA Technical Reports Server (NTRS)

    Frazer, Robert E.

    1988-01-01

    Proposed compound-wall configuration enables construction of large high-vacuum chambers without having to use thick layers of expensive material to obtain necessary strength. Walls enclose chambers more than 1 m in diameter and several kilometers long. Compound wall made of strong outer layer of structural-steel culvert pipe welded to thin layer of high-quality, low-outgassing stainless steel.

  1. Crater Wall With Gullies

    NASA Technical Reports Server (NTRS)

    2004-01-01

    8 June 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows gullies formed in the terraced wall of an impact crater on the floor of a larger crater near 39.1oS, 200.7oW. Gullies such as these are fairly common in craters and depressions at southern middle latitudes. They also occur in some areas at northern middle latitudes and in both polar regions. They may have formed by liquid water, or not--the Mars science community is still debating and discussing the issue. This picture covers an area about 3 km (1.9 mi) across. The scene is illuminated by sunlight from the upper left.

  2. Bacterial Cell Wall Components

    NASA Astrophysics Data System (ADS)

    Ginsberg, Cynthia; Brown, Stephanie; Walker, Suzanne

    Bacterial cell-surface polysaccharides cells are surrounded by a variety of cell-surface structures that allow them to thrive in extreme environments. Components of the cell envelope and extracellular matrix are responsible for providing the cells with structural support, mediating intercellular communication, allowing the cells to move or to adhere to surfaces, protecting the cells from attack by antibiotics or the immune system, and facilitating the uptake of nutrients. Some of the most important cell wall components are polysaccharide structures. This review discusses the occurrence, structure, function, and biosynthesis of the most prevalent bacterial cell surface polysaccharides: peptidoglycan, lipopolysaccharide, arabinogalactan, and lipoarabinomannan, and capsular and extracellular polysaccharides. The roles of these polysaccharides in medicine, both as drug targets and as therapeutic agents, are also described.

  3. Oven wall panel construction

    DOEpatents

    Ellison, Kenneth; Whike, Alan S.

    1980-04-22

    An oven roof or wall is formed from modular panels, each of which comprises an inner fabric and an outer fabric. Each such fabric is formed with an angle iron framework and somewhat resilient tie-bars or welded at their ends to flanges of the angle irons to maintain the inner and outer frameworks in spaced disposition while minimizing heat transfer by conduction and permitting some degree of relative movement on expansion and contraction of the module components. Suitable thermal insulation is provided within the module. Panels or skins are secured to the fabric frameworks and each such skin is secured to a framework and projects laterally so as slidingly to overlie the adjacent frame member of an adjacent panel in turn to permit relative movement during expansion and contraction.

  4. Crater Wall With Gullies

    NASA Technical Reports Server (NTRS)

    2004-01-01

    8 June 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows gullies formed in the terraced wall of an impact crater on the floor of a larger crater near 39.1oS, 200.7oW. Gullies such as these are fairly common in craters and depressions at southern middle latitudes. They also occur in some areas at northern middle latitudes and in both polar regions. They may have formed by liquid water, or not--the Mars science community is still debating and discussing the issue. This picture covers an area about 3 km (1.9 mi) across. The scene is illuminated by sunlight from the upper left.

  5. Arterial wall thermography.

    PubMed

    Diamantopoulos, Leonidas

    2003-06-01

    An atherosclerotic plaque is considered vulnerable when it is at higher risk of inducing acute cardiac events. The early detection and follow-up of the vulnerable plaque are crucial to prevent these events from happening. To date there are no proven techniques to detect such a plaque. Arterial wall thermography, tracing the heat signature of the activated macrophages, is a new and promising method in this direction. However, the difficulties of applying such a method in vivo should not be neglected. Current science proposes several potential thermographic methods. They can be generally categorized as noninvasive and invasive. Magnetic resonance thermometry (MRT) is the most important noninvasive method. It is novel, accurate, and reproducible, but is unfortunately hampered by resolution limitations due to the size and motion of the target vessels. The "infrared" and the "contact-sensor" are the most important invasive thermographic methods. Mainly due to the difficulties of infrared radiation in penetrating the flowing blood, the contact thermographic methods seem to be the most feasible at present. The superiority of thermal mapping of the arterial wall versus the localized temperature measurements is clear. The use of multiple thermal sensors arranged around the vessel's circumference and the application of motorized catheter pullback, not only ensure a large area of coverage, but also enable us to build thermal maps and vascular thermoanatomical reconstructions by using modern computer technology. It is expected that arterial thermography will undoubtedly initiate debate, mainly concerning the most appropriate therapy for the vulnerable plaque. Data collection and correct interpretation are expected to lead us into making wise decisions.

  6. North wall, central part, showing partial partition wall at left. ...

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

    North wall, central part, showing partial partition wall at left. This area is labeled “Pioneering Research” on drawing copy NV-35-B-5 (submitted with HABS No. NV-35-B) (series 2 of 4) - Bureau of Mines Metallurgical Research Laboratory, Original Building, Date Street north of U.S. Highway 93, Boulder City, Clark County, NV

  7. 7. INTERIOR, MAIN GARAGE, SOUTHERN WALL, FROM CLOSE TO WALL, ...

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

    7. INTERIOR, MAIN GARAGE, SOUTHERN WALL, FROM CLOSE TO WALL, LOOKING SOUTH, SHOWING 'GAMEWELL' FIRE ALARM TAPE CONTROL SYSTEM (TECHNOLOGY CIRCA 1910) AT CENTER, AND ENTRY TO OFFICE AT FAR RIGHT. - Oakland Naval Supply Center, Firehouse, East of Fourth Street, between A & B Streets, Oakland, Alameda County, CA

  8. 10. VIEW OF LAMINARFLOW FILTER WALL NEAR SOUTH WALL OF ...

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

    10. VIEW OF LAMINAR-FLOW FILTER WALL NEAR SOUTH WALL OF CLEAN ROOM (102). NOTE GROUNDING CABLES NEAR BASEBOARD IN LOWER RIGHT BACKGROUND. WHITE SQUARE IN FOREGROUND IS A FLOOR DRAIN COVERED WITH TAPE. - Vandenberg Air Force Base, Space Launch Complex 3, Vehicle Support Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  9. 13. LONG WEST WALL (LEFT) AND SHORT SOUTH WALL (RIGHT) ...

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

    13. LONG WEST WALL (LEFT) AND SHORT SOUTH WALL (RIGHT) OF AR-9, ALSO SHOWING MORE RECENT CONTROL ROOM BUILDING AT RIGHT. VIEW IS TO THE NORTHEAST. - Edwards Air Force Base, South Base, Rammed Earth Aircraft Dispersal Revetments, Western Shore of Rogers Dry Lake, Boron, Kern County, CA

  10. Moisture Research - Optimizing Wall Assemblies

    SciTech Connect

    Arena, L.; Mantha, P.

    2013-05-01

    The Consortium for Advanced Residential Buildings (CARB) evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls.

  11. The "Brick Wall" Graphic Organizer

    ERIC Educational Resources Information Center

    Matteson, Shirley M.

    2016-01-01

    A brick wall provides a fitting description of what happens when teachers try to teach a concept for which students are unprepared. When students are unsuccessful academically, their foundational knowledge may be missing, incomplete, or incorrect. As a result, students "hit a brick wall," and their academic progress stops because they do…

  12. Bacterial cell-wall recycling

    PubMed Central

    Johnson, Jarrod W.; Fisher, Jed F.; Mobashery, Shahriar

    2012-01-01

    Many Gram-negative and Gram-positive bacteria recycle a significant proportion of the peptidoglycan components of their cell walls during their growth and septation. In many—and quite possibly all—bacteria, the peptidoglycan fragments are recovered and recycled. While cell-wall recycling is beneficial for the recovery of resources, it also serves as a mechanism to detect cell-wall–targeting antibiotics and to regulate resistance mechanisms. In several Gram-negative pathogens, anhydro-MurNAc-peptide cell-wall fragments regulate AmpC β-lactamase induction. In some Gram-positive organisms, short peptides derived from the cell wall regulate the induction of both β-lactamase and β-lactam-resistant penicillin-binding proteins. The involvement of peptidoglycan recycling with resistance regulation suggests that inhibitors of the enzymes involved in the recycling might synergize with cell-wall-targeted antibiotics. Indeed, such inhibitors improve the potency of β-lactams in vitro against inducible AmpC β-lactamase-producing bacteria. We describe the key steps of cell-wall remodeling and recycling, the regulation of resistance mechanisms by cell-wall recycling, and recent advances toward the discovery of cell-wall recycling inhibitors. PMID:23163477

  13. The Wonders of Word Walls.

    ERIC Educational Resources Information Center

    Houle, Amy; Krogness, Allison

    2001-01-01

    Describes using a word wall, a visible display categorizing words alphabetically, enabling children in early childhood classrooms to discover new words and to practice and expand their language skills. Suggests that a word wall helps to create a secure learning environment, builds student confidence, and contributes to independent reading and…

  14. The Wonders of Word Walls.

    ERIC Educational Resources Information Center

    Houle, Amy; Krogness, Allison

    2001-01-01

    Describes using a word wall, a visible display categorizing words alphabetically, enabling children in early childhood classrooms to discover new words and to practice and expand their language skills. Suggests that a word wall helps to create a secure learning environment, builds student confidence, and contributes to independent reading and…

  15. The "Brick Wall" Graphic Organizer

    ERIC Educational Resources Information Center

    Matteson, Shirley M.

    2016-01-01

    A brick wall provides a fitting description of what happens when teachers try to teach a concept for which students are unprepared. When students are unsuccessful academically, their foundational knowledge may be missing, incomplete, or incorrect. As a result, students "hit a brick wall," and their academic progress stops because they do…

  16. Great Wall of China

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This ASTER sub-image covers a 12 x 12 km area in northern Shanxi Province, China, and was acquired January 9, 2001. The low sun angle, and light snow cover highlight a section of the Great Wall, visible as a black line running diagonally through the image from lower left to upper right. The Great Wall is over 2000 years old and was built over a period of 1000 years. Stretching 4500 miles from Korea to the Gobi Desert it was first built to protect China from marauders from the north.

    This image is located at 40.2 degrees north latitude and 112.8 degrees east longitude.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands Evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and

  17. Great Wall of China

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This ASTER sub-image covers a 12 x 12 km area in northern Shanxi Province, China, and was acquired January 9, 2001. The low sun angle, and light snow cover highlight a section of the Great Wall, visible as a black line running diagonally through the image from lower left to upper right. The Great Wall is over 2000 years old and was built over a period of 1000 years. Stretching 4500 miles from Korea to the Gobi Desert it was first built to protect China from marauders from the north.

    This image is located at 40.2 degrees north latitude and 112.8 degrees east longitude.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands Evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and

  18. Channel Wall Landslides

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The multiple landslides in this VIS image occur along a steep channel wall. Note the large impact crater in the context image. The formation of the crater may have initially weakened that area of the surface prior to channel formation.

    Image information: VIS instrument. Latitude -2.7, Longitude 324.8 East (35.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. Channel Wall Landslides

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The multiple landslides in this VIS image occur along a steep channel wall. Note the large impact crater in the context image. The formation of the crater may have initially weakened that area of the surface prior to channel formation.

    Image information: VIS instrument. Latitude -2.7, Longitude 324.8 East (35.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. Wall Shear Stress, Wall Pressure and Near Wall Velocity Field Relationships in a Whirling Annular Seal

    NASA Technical Reports Server (NTRS)

    Morrison, Gerald L.; Winslow, Robert B.; Thames, H. Davis, III

    1996-01-01

    The mean and phase averaged pressure and wall shear stress distributions were measured on the stator wall of a 50% eccentric annular seal which was whirling in a circular orbit at the same speed as the shaft rotation. The shear stresses were measured using flush mounted hot-film probes. Four different operating conditions were considered consisting of Reynolds numbers of 12,000 and 24,000 and Taylor numbers of 3,300 and 6,600. At each of the operating conditions the axial distribution (from Z/L = -0.2 to 1.2) of the mean pressure, shear stress magnitude, and shear stress direction on the stator wall were measured. Also measured were the phase averaged pressure and shear stress. These data were combined to calculate the force distributions along the seal length. Integration of the force distributions result in the net forces and moments generated by the pressure and shear stresses. The flow field inside the seal operating at a Reynolds number of 24,000 and a Taylor number of 6,600 has been measured using a 3-D laser Doppler anemometer system. Phase averaged wall pressure and wall shear stress are presented along with phase averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure and wall shear stress are very complex and do not follow simple bulk flow predictions.

  1. Wall Shear Stress, Wall Pressure and Near Wall Velocity Field Relationships in a Whirling Annular Seal

    NASA Technical Reports Server (NTRS)

    Morrison, Gerald L.; Winslow, Robert B.; Thames, H. Davis, III

    1996-01-01

    The mean and phase averaged pressure and wall shear stress distributions were measured on the stator wall of a 50% eccentric annular seal which was whirling in a circular orbit at the same speed as the shaft rotation. The shear stresses were measured using flush mounted hot-film probes. Four different operating conditions were considered consisting of Reynolds numbers of 12,000 and 24,000 and Taylor numbers of 3,300 and 6,600. At each of the operating conditions the axial distribution (from Z/L = -0.2 to 1.2) of the mean pressure, shear stress magnitude, and shear stress direction on the stator wall were measured. Also measured were the phase averaged pressure and shear stress. These data were combined to calculate the force distributions along the seal length. Integration of the force distributions result in the net forces and moments generated by the pressure and shear stresses. The flow field inside the seal operating at a Reynolds number of 24,000 and a Taylor number of 6,600 has been measured using a 3-D laser Doppler anemometer system. Phase averaged wall pressure and wall shear stress are presented along with phase averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure and wall shear stress are very complex and do not follow simple bulk flow predictions.

  2. Denitrification Walls: Successes and Limitations.

    NASA Astrophysics Data System (ADS)

    Schipper, L. A.; Barkle, G. F.; Burgess, C. P.; Vojvodic-Vukovic, M.

    2001-05-01

    There is a need to develop practical and inexpensive approaches for removing nitrate from ground water because of its potential adverse effect on receiving aquatic environments. Denitrification walls may be one such approach for removing nitrate from shallow groundwater. In January 1996, we constructed a denitrification wall by digging a trench that intercepted groundwater and mixed the excavated soil with sawdust before the mix was returned to the trench. Sawdust provides a source of energy for denitrifying bacteria, which convert nitrate in groundwater entering the wall to nitrogen gas. For the past 5 years, nitrate concentrations in groundwater entering this wall have ranged from 5 to 16 mg N L-1 but have always been reduced to less than 2 mg N L-1 in the wall indicating nearly complete removal of nitrate from the groundwater. We showed that this nitrate removal could be accounted for by denitrification rates which ranged from 0.6 to 18.1 mg N m-3 h-1. More recently we have encountered problems with denitrification walls constructed into coarsely textured soils (such as sands) where the addition of sawdust decreased hydraulic conductivity. As a consequence groundwater flowed under rather than through the wall. We are attempting to circumvent this problem using coarser grades of carbon amendments. Particulate carbon (such as sawdust) is likely to support lower rates of nitrate removal, but for longer, than soluble carbon sources because solid carbon sources degrade more slowly.

  3. Diplopia and orbital wall fractures.

    PubMed

    Boffano, Paolo; Roccia, Fabio; Gallesio, Cesare; Karagozoglu, K Hakki; Forouzanfar, Tymour

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and such fractures. This study is based on 2 databases that have continuously recorded data of patients hospitalized with maxillofacial fractures between 2001 and 2010. On the whole, 447 patients (334 males, 113 females) with pure blow-out orbital wall fractures were included. The most frequently involved orbital site was the floor (359 fractures), followed by medial wall (41 fractures) and lateral wall (5 fractures). At presentation, 227 patients (50.7%) had evidence of diplopia. In particular, in most patients, a diplopia in all directions was referred (78 patients). Statistically significant associations were found between diplopia on eye elevation and orbital floor fractures (P < 0.05) and between horizontal diplopia and medial wall fractures (P < 0.000005). In patients under evaluation for orbital trauma, the observation of diplopia on eye elevation and horizontal diplopia at presentation could be useful clinical indicators orbital floor and medial wall fractures, respectively.

  4. Reduction of wind tunnel wall interference by controlled wall flow

    NASA Technical Reports Server (NTRS)

    Bernstein, S. (Editor); Joppa, R. G.

    1975-01-01

    An alternate method of testing was developed in which flow through the porous walls of the tunnel was actively controlled so as to approximate free air conditions in the neighborhood of the model during the test. The amount and distribution of the controlled flow through the walls is computed using a potential flow representation of the model based on the measured lift. Theoretical analysis is presented to prove the convergence of the method to free air conditions and to substantiate the general three-dimensional theory of operation when the normal flow distribution is continuous. A two-dimensional tunnel was constructed to evaluate the concept. Results show that substantial reduction of wall interference may be achieved with relatively low values of porosity of actively controlled walls.

  5. 27. "TEST STAND; STRUCTURAL; SIDEWALL, NORTH WALL AND SOUTH WALL ...

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

    27. "TEST STAND; STRUCTURAL; SIDEWALL, NORTH WALL AND SOUTH WALL FRAMING ELEVATIONS." Specifications No. ENG-04353-55-72; Drawing No. 60-09-12; sheet 27 of 148; file no. 1320/78. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract no. 4338, Rev. B; date: 15 April 1957. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  6. OTVE combustor wall condition monitoring

    NASA Technical Reports Server (NTRS)

    Szemenyei, Brian; Nelson, Robert S.; Barkhoudarian, S.

    1989-01-01

    Conventional ultrasonics, eddy current, and electromagnetic acoustic transduction (EMAT) technologies were evaluated to determine their capability of measuring wall thickness/wear of individual cooling channels in test specimens simulating conditions in the throat region of an OTVE combustion chamber liner. Quantitative results are presented for the eddy current technology, which was shown to measure up to the optimum 20-mil wall thickness with near single channel resolution. Additional results demonstrate the capability of the conventional ultrasonics and EMAT technologies to detect a thinning or cracked wall. Recommendations for additional eddy current and EMAT development tests are presented.

  7. Economics of abdominal wall reconstruction.

    PubMed

    Bower, Curtis; Roth, J Scott

    2013-10-01

    The economic aspects of abdominal wall reconstruction are frequently overlooked, although understandings of the financial implications are essential in providing cost-efficient health care. Ventral hernia repairs are frequently performed surgical procedures with significant economic ramifications for employers, insurers, providers, and patients because of the volume of procedures, complication rates, the significant rate of recurrence, and escalating costs. Because biological mesh materials add significant expense to the costs of treating complex abdominal wall hernias, the role of such costly materials needs to be better defined to ensure the most cost-efficient and effective treatments for ventral abdominal wall hernias.

  8. Domain walls riding the wave.

    SciTech Connect

    Karapetrov, G.; Novosad, V.; Materials Science Division

    2010-11-01

    Recent years have witnessed a rapid proliferation of electronic gadgets around the world. These devices are used for both communication and entertainment, and it is a fact that they account for a growing portion of household energy consumption and overall world consumption of electricity. Increasing the energy efficiency of these devices could have a far greater and immediate impact than a gradual switch to renewable energy sources. The advances in the area of spintronics are therefore very important, as gadgets are mostly comprised of memory and logic elements. Recent developments in controlled manipulation of magnetic domains in ferromagnet nanostructures have opened opportunities for novel device architectures. This new class of memories and logic gates could soon power millions of consumer electronic devices. The attractiveness of using domain-wall motion in electronics is due to its inherent reliability (no mechanical moving parts), scalability (3D scalable architectures such as in racetrack memory), and nonvolatility (retains information in the absence of power). The remaining obstacles in widespread use of 'racetrack-type' elements are the speed and the energy dissipation during the manipulation of domain walls. In their recent contribution to Physical Review Letters, Oleg Tretiakov, Yang Liu, and Artem Abanov from Texas A&M University in College Station, provide a theoretical description of domain-wall motion in nanoscale ferromagnets due to the spin-polarized currents. They find exact conditions for time-dependent resonant domain-wall movement, which could speed up the motion of domain walls while minimizing Ohmic losses. Movement of domain walls in ferromagnetic nanowires can be achieved by application of external magnetic fields or by passing a spin-polarized current through the nanowire itself. On the other hand, the readout of the domain state is done by measuring the resistance of the wire. Therefore, passing current through the ferromagnetic wire is

  9. My Big Wall

    NASA Technical Reports Server (NTRS)

    Espinosa, Paul S.

    2002-01-01

    It was June and I was in Yosemite National Park in California, 2,000-feet off the ground. I was climbing El Capitan, a majestic 3,000-foot high, mile-wide granite monolith--one of the most sought after and spectacular rock climbs in the world. After three days of climbing on its sheer face, and having completed the most difficult part of the route, my partner and I were heading down. A thunderstorm lasting all night and into the morning had soaked our tiny perch and all our worldly possessions. We began rappelling down the vertical wall by sliding to the ends of two 50meter ropes tied together and looped through a set of fixed rings bolted into the rock. At the end of the ropes was another rappel station consisting of a set of rings, placed by previous climbers for retreating parties, which we used to anchor ourselves to the rock face. We then pulled the ropes down from the rings above, threaded the ones in front of our noses and started down another rope length. Everything we brought up for our five-day climb to the summit we had to bring back down with us: ropes, climbing gear of every sort, sleeping bags, extra clothes, food, water, and other essentials. All this we either stuffed into a haul bag (an oversized reinforced duffel bag) or slung over our shoulders. The retreat was slow and methodical, akin to a train backing down a mountain, giving me ample time to think. My situation made me think about my work, mostly, about all the projects I have managed, or been involved in managing. As a NASA project manager, I have worked on a number of successful projects. I have also been involved in a number of projects I never saw the end of. I thought about all the projects I transferred off of for other opportunities, projects that were in full stride and ran out of funding, and ones put on the shelf because they would not meet a flight date. Oh yes, I have had many success, to be sure, or I would have burned out years ago. Lessons from both the successful and not

  10. Fly on the Wall

    NASA Technical Reports Server (NTRS)

    Mulenburg, Gerald

    2003-01-01

    The email was addressed not only to me, but also to all the Project Knowledge Sharing Community at Ames Research Center. We were invited to sit in on a major project review as a new experiment in knowledge sharing. This first-of-its-kind opportunity had been conceived by Claire Smith, who leads the knowledge sharing program, as well as heading up the Center's Project Leadership Development Program and serving as coordinator of the APPL-West program at Ames. The objective was to offer Ames project practitioners the opportunity to observe project-review processes as they happen. Not that I haven't participated in my share of project reviews, but this seemed like a great way for me to get up-to-date about a new project, the Kepler mission, and to experience a review from a new perspective. Typically, when you're being reviewed, it's difficult to see what's happening objectively-the same way it is on a project. Presenters are always thinking, 'Okay, what's on my slides? How much time do I have left? What are they going to ask me?' So when Claire's email pinged on my computer, I quickly responded by asking her to save a place for me. It was to be an informational review about progress on the project: what the team had done, where they were going, and what they needed to do to get there. There were people on the project team from all over the United States, and it was the first time for them to get together from all aspects of the project. For our part, as observers, we were asked to abide by a couple of rules: Don't ask any questions. and don't talk about the specifics of what we saw or heard. The idea was that we weren't supposed to be noticed. We weren't to buzz around and bother people. Hence the name for this experinient: Fly on the Wall.

  11. Hall thruster with grooved walls

    NASA Astrophysics Data System (ADS)

    Li, Hong; Ning, Zhongxi; Yu, Daren

    2013-02-01

    Axial-oriented and azimuthal-distributed grooves are formed on channel walls of a Hall thruster after the engine undergoes a long-term operation. Existing studies have demonstrated the relation between the grooves and the near-wall physics, such as sheath and electron near-wall transport. The idea to optimize the thruster performance with such grooves was also proposed. Therefore, this paper is devoted to explore the effects of wall grooves on the discharge characteristics of a Hall thruster. With experimental measurements, the variations on electron conductivity, ionization distribution, and integrated performance are obtained. The involved physical mechanisms are then analyzed and discussed. The findings help to not only better understand the working principle of Hall thruster discharge but also establish a physical fundamental for the subsequent optimization with artificial grooves.

  12. Injuries on British climbing walls.

    PubMed Central

    Limb, D

    1995-01-01

    A postal survey was carried out of the 90 most accessible climbing walls in England, Scotland and Wales to determine the incidence and nature of injuries requiring emergency treatment associated with their use. Over a two year period, representing 1.021 million visits to the 56 walls used by more than 30 climbers per week, 55 significant injuries were recorded. The rate of injury was not related to any identified design or safety feature of the walls, although upper limb injuries were proportionally more common in walls which provided thinner fixed landing mats rather than thicker, moveable crash mats. The overall rate of injury was very low and climbers seem to modify risk taking behaviour and thus compensate for the level of safety equipment available. It may be possible to reduce the injury rate further by providing seamless ground cover with matting of adequate energy absorbency. Images Figure 1 PMID:8800849

  13. Plant cell walls to ethanol.

    USDA-ARS?s Scientific Manuscript database

    Conversion of plant cell walls to ethanol constitutes generation 2 bioethanol production. The process consists of several steps: biomass selection/genetic modification, physiochemical pretreatment, enzymatic saccharification, fermentation, and separation. Ultimately, it is desired to combine as man...

  14. Wall effects in wind tunnels

    NASA Technical Reports Server (NTRS)

    Chevallier, J. P.; Vaucheret, X.

    1986-01-01

    A synthesis of current trends in the reduction and computation of wall effects is presented. Some of the points discussed include: (1) for the two-dimensional, transonic tests, various control techniques of boundary conditions are used with adaptive walls offering high precision in determining reference conditions and residual corrections. A reduction in the boundary layer effects of the lateral walls is obtained at T2; (2) for the three-dimensional tests, the methods for the reduction of wall effects are still seldom applied due to a lesser need and to their complexity; (3) the supports holding the model of the probes have to be taken into account in the estimation of perturbatory effects.

  15. Simulation of turbulent wall pressure

    NASA Technical Reports Server (NTRS)

    Ash, R. L.

    1976-01-01

    A computer program has been developed to simulate the transient wall pressure field produced by a low speed fully turbulent boundary layer. The theoretical basis for the simulation has been discussed and preliminary results from a pressure simulation are presented.

  16. Wall force produced during disruptions

    NASA Astrophysics Data System (ADS)

    Strauss, H.; Paccagnella, R.; Breslau, J.

    2009-11-01

    The study of disruptions is of great importance for ITER. Previous work on disruptions [1] is extended to compute toroidally asymmetric wall force in ITER, using the M3D code. The disruptions are produced by n = 1 resistive wall modes or external kink modes. A thin wall resistive boundary model is used to calculate the wall forces. The symmetric wall force, produced by a VDE, and the asymmetric wall force, produced by n = 1 modes, are comparable in magnitude. It is found that the asymmetric and axisymmetric forces scale with the growth rate of the instability multiplied by the square of the current divided by magnetic field. A similar scaling was reported for VDEs in JET [2]. Numerically, the study of disruptions is very challenging. In the M3D extended MHD code, dealiasing was applied in the toroidal direction. Advection terms were treated with a numerical upwind method. These techniques provided sufficient numerical stability to simulate entire disruption events. [4pt] [1] R. Paccagnella, H. R. Strauss, and J. Breslau, Nucl. Fusion (2009) 49 035003. [2] V. Riccardo, T. C. Hender, P. J. Lomas, et al., Plasma Phys. Control. Fusion (2004)

  17. Plasma Wall Interaction and Its Control by Wall Conditioning

    SciTech Connect

    Philipps, V

    2004-03-15

    The surrounding material walls in fusion devices must fulfil three important tasks:provide high vacuum conditions necessary to provide clean fusion plasmas absorb the power produced by the {alpha}-particles in the fusion processes and injected by auxiliary heating enable the exhaust of the helium ash by thermalisation of the helium plasma ions on material surfaces in the vicinity of helium pumps.The interaction of the plasma with the surrounding wall surfaces (PSI: plasma surface interaction) is therefore a necessary condition for fusion devices and not to avoid. In the plasma wall interaction a variety of bulk material and surface processes are involved on one side together with various special processes in the near surface plasma region on the other side. They can modify the properties of the boundary and main plasma in a feed back like behaviour. A prominent example is the release of impurities from the walls by plasma particle impact which increases the energy loss of the plasma by radiation and reduces thereby the particle fluxes to and impurity release from the walls.

  18. Innovative Composite Wall System for Sheathing Masonry Walls

    SciTech Connect

    Wendt, Robert L.; Cavallo, James

    1997-09-25

    Existing Housing - Much of the older multifamily housing stock in the United States includes units in structures with uninsulated masonry walls. Included in this stock are two- and three-story walk-up apartments, larger apartment complexes, and public housing (both high- rise and townhouse). This older multifamily housing has seen years of heavy use that may have left the plaster wall marred or damaged. Long- term building settlement or movement may have cracked the plaster, sometimes severely. Moisture from invented kitchens and baths may have caused condensation on uninsulated exterior walls. At best this condensation has left stains on the paint or wallpaper. At worst it has supported mold and mildew growth, fouling the air and creating unhealthy living conditions. Deteriorating plaster and flaking paint also result from wet walls. The presence of flaking, lead-based paint in older (pre-1978) housing is a major public health concern. Children can suffer permanent mental handicaps and psychological disorders if they are subjected to elevated levels of lead, while adults can suffer hypertension and other maladies. Studies have found that, in some urban communities with older housing stocks, over 35% of children tested have elevated blood lead levels (Hastings, et al.: 1997). Nationally, nearly 22% of black, non-hispanic children living in pre-1946 housing were found to have elevated levels of lead in their blood (MWWR Article: February 21,1997). The deterioration of many of these walls is to the point that lead can freely enter the living space.

  19. Wall thickness effect on the resistive wall mode stability in toroidal plasmas

    SciTech Connect

    Zheng, L.-J.; Kotschenreuther, M.T.

    2005-07-15

    The effect of finite wall thickness on the stability of n=1 resistive wall modes in toroidal plasmas is investigated. A fusion reactor-relevant configuration is examined. The investigation employs a novel ideal-magnetohydrodynamics adaptive shooting code for axisymmetric plasmas, extended to take into account the wall thickness. Although finite wall thickness generally reduces the growth rate of the resistive wall modes, no contribution to stabilization is found to be made by the portion of the wall that is located beyond the critical position for perfectly conducting wall stabilization. Thus, when the inner side of the wall lies near the critical wall position, the scaling of the growth rate versus wall thickness in the realistic thick-wall calculation is significantly different from that of the usual thin-wall theory. The thin-wall estimate is relevant only when the wall is brought very close to the plasma and is not too thick.

  20. Effects of the flexibility of the arterial wall on the wall shear stresses and wall tension in Abdominal Aortic Aneurysms.

    NASA Astrophysics Data System (ADS)

    Salsac, Anne-Virginie; Fernandez, Miguel; Chomaz, Jean-Marc

    2005-11-01

    As an abdominal aortic aneurysm develops, large changes occur in the composition and structure of the arterial wall, which result in its stiffening. So far, most studies, whether experimental or numerical, have been conducted assuming the walls to be rigid. A numerical simulation of the fluid structure interactions is performed in different models of aneurysms in order to analyze the effects that the wall compliance might have on the flow topology. Both symmetric and non-symmetric models of aneurysms are considered, all idealistic in shape. The wall mechanical properties are varied in order to simulate the progressive stiffening of the walls. The spatial and temporal distributions of wall tension are calculated for the different values of the wall elasticity and compared to the results for the rigid walls. In the case of rigid walls, the calculation of the wall shear stresses and pressure compare very well with experimental results.

  1. MHD Electrode and wall constructions

    DOEpatents

    Way, Stewart; Lempert, Joseph

    1984-01-01

    Electrode and wall constructions for the walls of a channel transmitting the hot plasma in a magnetohydrodynamic generator. The electrodes and walls are made of a plurality of similar modules which are spaced from one another along the channel. The electrodes can be metallic or ceramic, and each module includes one or more electrodes which are exposed to the plasma and a metallic cooling bar which is spaced from the plasma and which has passages through which a cooling fluid flows to remove heat transmitted from the electrode to the cooling bar. Each electrode module is spaced from and electrically insulated from each adjacent module while interconnected by the cooling fluid which serially flows among selected modules. A wall module includes an electrically insulating ceramic body exposed to the plasma and affixed, preferably by mechanical clips or by brazing, to a metallic cooling bar spaced from the plasma and having cooling fluid passages. Each wall module is, similar to the electrode modules, electrically insulated from the adjacent modules and serially interconnected to other modules by the cooling fluid.

  2. Isolation of the Cell Wall.

    PubMed

    Canut, Hervé; Albenne, Cécile; Jamet, Elisabeth

    2017-01-01

    This chapter describes a method allowing the purification of the cell wall for studying both polysaccharides and proteins. The plant primary cell wall is mainly composed of polysaccharides (90-95 % in mass) and of proteins (5-10 %). At the end of growth, specialized cells may synthesize a lignified secondary wall composed of polysaccharides (about 65 %) and lignin (about 35 %). Due to its composition, the cell wall is the cellular compartment having the highest density and this property is used for its purification. It plays critical roles during plant development and in response to environmental constraints. It is largely used in the food and textile industries as well as for the production of bioenergy. All these characteristics and uses explain why its study as a true cell compartment is of high interest. The proposed method of purification can be used for large amount of material but can also be downscaled to 500 mg of fresh material. Tools for checking the quality of the cell wall preparation, such as protein analysis and microscopy observation, are also provided.

  3. Functional domain walls in multiferroics.

    PubMed

    Meier, Dennis

    2015-11-25

    During the last decade a wide variety of novel and fascinating correlation phenomena has been discovered at domain walls in multiferroic bulk systems, ranging from unusual electronic conductance to inseparably entangled spin and charge degrees of freedom. The domain walls represent quasi-2D functional objects that can be induced, positioned, and erased on demand, bearing considerable technological potential for future nanoelectronics. Most of the challenges that remain to be solved before turning related device paradigms into reality, however, still fall in the field of fundamental condensed matter physics and materials science. In this topical review seminal experimental findings gained on electric and magnetic domain walls in multiferroic bulk materials are addressed. A special focus is put on the physical properties that emerge at so-called charged domain walls and the added functionality that arises from coexisting magnetic order. The research presented in this review highlights that we are just entering a whole new world of intriguing nanoscale physics that is yet to be explored in all its details. The goal is to draw attention to the persistent challenges and identify future key directions for the research on functional domain walls in multiferroics.

  4. Turbine airfoil with outer wall thickness indicators

    DOEpatents

    Marra, John J; James, Allister W; Merrill, Gary B

    2013-08-06

    A turbine airfoil usable in a turbine engine and including a depth indicator for determining outer wall blade thickness. The airfoil may include an outer wall having a plurality of grooves in the outer surface of the outer wall. The grooves may have a depth that represents a desired outer surface and wall thickness of the outer wall. The material forming an outer surface of the outer wall may be removed to be flush with an innermost point in each groove, thereby reducing the wall thickness and increasing efficiency. The plurality of grooves may be positioned in a radially outer region of the airfoil proximate to the tip.

  5. Domain Walls in Bent Nanowires

    NASA Astrophysics Data System (ADS)

    Lofink, F.; Philippi-Kobs, A.; Rahbar Azad, M. R.; Hankemeier, S.; Hoffmann, G.; Frömter, R.; Oepen, H. P.

    2017-08-01

    The influence of geometric parameters on the magnetic fine structure of domain walls in bent nanowires is investigated. The domain pattern in the soft-magnetic Co39Fe54Si7 alloy is studied via scanning electron microscopy with polarization analysis and modeled via micromagnetic simulations. It is demonstrated that the bending angle affects details of the microstructure as well as the preponderant domain-wall type. A phenomenological model is developed that provides the global energy minimum of individual types of domain walls as a function of the geometric parameters of the wire. The results can be directly transferred to permalloy wires, as permalloy and Co39Fe54Si7 alloy have a comparable magnetostatic exchange length.

  6. Stadium billiard with moving walls.

    PubMed

    Cohen, Doron; Wisniacki, Diego A

    2003-02-01

    We study the evolution of the energy distribution for a stadium with moving walls. We consider a one period driving cycle, which is characterized by an amplitude A and a wall velocity V. This evolving energy distribution has both "parametric" and "stochastic" components. The latter are important for the theory of quantum irreversibility and dissipation in driven mesoscopic devices. For an extremely slow wall velocity V, the spreading mechanism is dominated by transitions between neighboring levels, while for larger (nonadiabatic) velocities, the spreading mechanism has both perturbative and nonperturbative features. We present a numerical study which is aimed at identifying the latter features. A procedure is developed for the determination of the various V regimes. The possible implications of linear response theory are discussed.

  7. The DEMO wall load challenge

    NASA Astrophysics Data System (ADS)

    Wenninger, R.; Albanese, R.; Ambrosino, R.; Arbeiter, F.; Aubert, J.; Bachmann, C.; Barbato, L.; Barrett, T.; Beckers, M.; Biel, W.; Boccaccini, L.; Carralero, D.; Coster, D.; Eich, T.; Fasoli, A.; Federici, G.; Firdaouss, M.; Graves, J.; Horacek, J.; Kovari, M.; Lanthaler, S.; Loschiavo, V.; Lowry, C.; Lux, H.; Maddaluno, G.; Maviglia, F.; Mitteau, R.; Neu, R.; Pfefferle, D.; Schmid, K.; Siccinio, M.; Sieglin, B.; Silva, C.; Snicker, A.; Subba, F.; Varje, J.; Zohm, H.

    2017-04-01

    For several reasons the challenge to keep the loads to the first wall within engineering limits is substantially higher in DEMO compared to ITER. Therefore the pre-conceptual design development for DEMO that is currently ongoing in Europe needs to be based on load estimates that are derived employing the most recent plasma edge physics knowledge. An initial assessment of the static wall heat load limit in DEMO infers that the steady state peak heat flux limit on the majority of the DEMO first wall should not be assumed to be higher than 1.0 MW m‑2. This compares to an average wall heat load of 0.29 MW m‑2 for the design {\\tt {EU}}{\\tt {~}}{\\tt {DEMO1}}{\\tt {~2015}} assuming a perfect homogeneous distribution. The main part of this publication concentrates on the development of first DEMO estimates for charged particle, radiation, fast particle (all static) and disruption heat loads. Employing an initial engineering wall design with clear optimization potential in combination with parameters for the flat-top phase (x-point configuration), loads up to 7 MW m‑2 (penalty factor for tolerances etc not applied) have been calculated. Assuming a fraction of power radiated from the x-point region between 1/5 and 1/3, peaks of the total power flux density due to radiation of 0.6–0.8 MW m‑2 are found in the outer baffle region. This first review of wall loads, and the associated limits in DEMO clearly underlines a significant challenge that necessitates substantial engineering efforts as well as a considerable consolidation of the associated physics basis.

  8. Gullies in Terraced Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-375, 29 May 2003

    Gullies--possibly formed by a liquid such as water in the recent martian past--formed at two different levels in the walls of a meteor impact crater near 36.2oS, 185.5oW. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies in the upper crater wall (top of the image) and emergent from the slope of a lower terrace (bottom of the image). Sunlight illuminates the scene from the upper left.

  9. [Structure of the interalveolar wall].

    PubMed

    Senelar, R

    1975-01-01

    The wall, which unites as well as separates two contiguous pulmonary alveoli is composed of: - a conjuntival partition, the veritable skeleton of the wall, which is occupied, to the largest extent, by capillary blood vessels. Between the capillaries, conjunctival cells are dispursed: fibrocytes, fibroblasts and histiocytes, of which some can be mobilised, transformed into macrophages, and penetrate into the alveolar lumen; - modified epithelial cells, whose very thin, vast expansions cover the conjunctival partition; - a liquid film, 0.2 mu in thickness, which separates the epithelial cells, or pneumocytes from the alveolar air. Numerous physiological implications result from this organisation.

  10. Sporothrix schenckii Cell Wall Peptidorhamnomannans

    PubMed Central

    Lopes-Bezerra, Leila M.

    2011-01-01

    This mini-review article is dedicated to clarifying certain important biochemical aspects of Sporothrix schenckii cell wall peptidorhamnomannans. Cell wall components involved in the host interaction such as antigens as well as a gp70 adhesin are important molecules present on the surface of the yeast parasitic phase. Other structural glycoconjugates present on the fungus cell surface are also described here. Knowledge of the fine structure of carbohydrate epitopes expressed on the surface in both morphological phases of S. schenckii permitted the development of non-invasive immunochemical methods to diagnose human and feline sporotrichosis. PMID:22203817

  11. Gullies in Terraced Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-375, 29 May 2003

    Gullies--possibly formed by a liquid such as water in the recent martian past--formed at two different levels in the walls of a meteor impact crater near 36.2oS, 185.5oW. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies in the upper crater wall (top of the image) and emergent from the slope of a lower terrace (bottom of the image). Sunlight illuminates the scene from the upper left.

  12. Recovery after abdominal wall reconstruction.

    PubMed

    Jensen, Kristian Kiim

    2017-03-01

    Incisional hernia is a common long-term complication to abdominal surgery, occurring in more than 20% of all patients. Some of these hernias become giant and affect patients in several ways. This patient group often experiences pain, decreased perceived body image, and loss of physical function, which results in a need for surgical repair of the giant hernia, known as abdominal wall reconstruction. In the current thesis, patients with a giant hernia were examined to achieve a better understanding of their physical and psychological function before and after abdominal wall reconstruction. Study I was a systematic review of the existing standardized methods for assessing quality of life after incisional hernia repair. After a systematic search in the electronic databases Embase and PubMed, a total of 26 studies using standardized measures for assessment of quality of life after incisional hernia repair were found. The most commonly used questionnaire was the generic Short-Form 36, which assesses overall health-related quality of life, addressing both physical and mental health. The second-most common questionnaire was the Carolinas Comfort Scale, which is a disease specific questionnaire addressing pain, movement limitation and mesh sensation in relation to a current or previous hernia. In total, eight different questionnaires were used at varying time points in the 26 studies. In conclusion, standardization of timing and method of quality of life assessment after incisional hernia repair was lacking. Study II was a case-control study of the effects of an enhanced recovery after surgery pathway for patients undergoing abdominal wall reconstruction for a giant hernia. Sixteen consecutive patients were included prospectively after the implementation of a new enhanced recovery after surgery pathway at the Digestive Disease Center, Bispebjerg Hospital, and compared to a control group of 16 patients included retrospectively in the period immediately prior to the

  13. Thermal breaking systems for metal stud walls -- Can metal stud walls perform as well as wood stud walls

    SciTech Connect

    Kosny, J.; Christian, J.E.; Desjarlais, A.O.

    1997-12-31

    Metal stud wall systems for residential buildings are gaining in popularity. Strong thermal bridges caused by highly conductive metal studs degrade the thermal performance of such walls. Several wall configurations have been developed to improve their thermal performance. The authors tried to evaluate some of these wall systems. The thermal performance of metal stud walls is frequently compared with that of wood stud walls. A reduction of the in-cavity R-value caused by the wood studs is about 10% in wood stud walls. In metal stud walls, thermal bridges generated by the metal components reduce their thermal performance by up to 55%. Today, metal stud walls are believed to be considerably less thermally effective than similar systems made of wood because steel has much higher thermal conductivity than wood. Relatively high R-values may be achieved by installing insulating sheathing, which is now widely recommended as the remedy for weak thermal performance of metal stud walls. A series of promising metal stud wall configurations was analyzed. Some of these walls were designed and tested by the authors, some were tested in other laboratories, and some were developed and forgotten a long time ago. Several types of thermal breaking systems were used in these walls. Two- and three-dimensional finite-difference computer simulations were used to analyze 20 metal stud wall configurations. Also, a series of hot-box tests were conducted on several of these walls. Test results for 22 additional metal stud walls were analyzed. Most of these walls contained conventional metal studs. Commonly used fiberglass and EPS were used as insulation materials. The most promising metal stud wall configurations have reductions in the center-of-cavity R-values of less than 20%.

  14. Chapter 3 Cell Wall Chemistry

    Treesearch

    Roger M. Rowell; Roger Pettersen; Mandla A. Tshabalala

    2012-01-01

    Wood is best defined as a three-dimensional biopolymer composite composed of an interconnected network of cellulose, hemicelluloses and lignin with minor amounts of extractives, and inorganics. The major chemical component of a living tree is water, but on a dry weight basis, all wood cell walls consist mainly of sugar-based polymers (carbohydrates, 65-75%) that are...

  15. Designing a Sound Reducing Wall

    ERIC Educational Resources Information Center

    Erk, Kendra; Lumkes, John; Shambach, Jill; Braile, Larry; Brickler, Anne; Matthys, Anna

    2015-01-01

    Acoustical engineers use their knowledge of sound to design quiet environments (e.g., classrooms and libraries) as well as to design environments that are supposed to be loud (e.g., concert halls and football stadiums). They also design sound barriers, such as the walls along busy roadways that decrease the traffic noise heard by people in…

  16. Chuck Close: "Off the Wall."

    ERIC Educational Resources Information Center

    Gardner, Michael

    2001-01-01

    Describes the planning and design process of "Off the Wall," a student-developed CD-ROM multimedia project about the life and work of artist Chuck Close-the product of a studio-based course in Learning Experiments Design at the University of Georgia. The design includes an element of gaming; text is kept sparse; navigational elements are rendered…

  17. Tube-Wall Thickness Detector

    NASA Technical Reports Server (NTRS)

    Kleint, R. E.; Baily, R. D.

    1985-01-01

    Eddy-current measurements detect wear of thin walls (0.01 in) (0.25 mm) in small diameter (0.19 in) (5 mm) heat exchanger tubing. Flexible durable thin rod inserts eddy-current coil into the heatexchanger tube.

  18. The Writing on the Wall.

    ERIC Educational Resources Information Center

    Sartorius, Tara Cady

    2000-01-01

    Focuses on the artwork of William Christenberry, specifically on his work "Alabama Wall (Variant)," which was constructed with remnants of material culture found along Alabama rural roads. Includes a reproduction of this artwork and activities for natural science, language arts, visual arts, social studies, and history/economics. (CMK)

  19. Tube-Wall Thickness Detector

    NASA Technical Reports Server (NTRS)

    Kleint, R. E.; Baily, R. D.

    1985-01-01

    Eddy-current measurements detect wear of thin walls (0.01 in) (0.25 mm) in small diameter (0.19 in) (5 mm) heat exchanger tubing. Flexible durable thin rod inserts eddy-current coil into the heatexchanger tube.

  20. Statistical characteristics of simulated walls

    NASA Astrophysics Data System (ADS)

    Demiański, M.; Doroshkevich, A. G.; Müller, V.; Turchaninov, V.

    2000-11-01

    The large-scale matter distribution in three different simulations of CDM models is investigated and compared with corresponding results of the Zel'dovich theory of non-linear gravitational instability. We show that the basic characteristics of wall-like structure elements are well described by this theory, and that they can be expressed by the cosmological parameters and a few spectral moments of the perturbation spectrum. Therefore the characteristics of such elements provide reasonable estimates of these parameters. We show that the compressed matter is relaxed and gravitationally confined and manifests itself in the existence of walls as (quasi-)stationary structure elements with a lifetime restricted by their disruption into high-density clouds. The matter distribution is investigated in both real and redshift spaces. In both cases almost the same particles form the walls, and we estimate differences in corresponding wall characteristics. The same methods are applied to several mock catalogues of `galaxies', which allows us to characterize a large-scale bias between the spatial distribution of dark matter and of simulated `galaxies'.

  1. Wary Eyes Monitoring Wall Street

    ERIC Educational Resources Information Center

    Jacobson, Linda

    2008-01-01

    School business officials kept a close watch on the financial markets this week--and on district investment portfolios and teacher-retirement funds--as stock prices gyrated and once-sound institutions got government bailouts or crumbled into bankruptcy. While financial observers said it was too soon to predict how Wall Street's upheaval might…

  2. Shear wall ultimate drift limits

    SciTech Connect

    Duffey, T.A.; Goldman, A.; Farrar, C.R.

    1994-04-01

    Drift limits for reinforced-concrete shear walls are investigated by reviewing the open literature for appropriate experimental data. Drift values at ultimate are determined for walls with aspect ratios ranging up to a maximum of 3.53 and undergoing different types of lateral loading (cyclic static, monotonic static, and dynamic). Based on the geometry of actual nuclear power plant structures exclusive of containments and concerns regarding their response during seismic (i.e.,cyclic) loading, data are obtained from pertinent references for which the wall aspect ratio is less than or equal to approximately 1, and for which testing is cyclic in nature (typically displacement controlled). In particular, lateral deflections at ultimate load, and at points in the softening region beyond ultimate for which the load has dropped to 90, 80, 70, 60, and 50 percent of its ultimate value, are obtained and converted to drift information. The statistical nature of the data is also investigated. These data are shown to be lognormally distributed, and an analysis of variance is performed. The use of statistics to estimate Probability of Failure for a shear wall structure is illustrated.

  3. Reconstruction of chest wall defects.

    PubMed

    Hasse, J

    1991-12-01

    A series of 61 consecutive procedures of chest wall resection and reconstruction in 58 patients during the period between August, 1986 and December, 1990 is reported. The ages ranged between 6-77 years. The chest wall resection was indicated for malignant affections in 54 cases. Among these, there were 24 patients with bronchial carcinoma invading the chest wall, 17 patients with primary or metastatic sarcoma, 11 patients with recurrent breast cancer and 3 with cancer metastases of varying origin. Pulmonary resection included pneumonectomy in 8 cases, lobectomy in 19, segmental and wedge resections in 26. In the majority of resections, the reconstruction was accomplished without implants. In cases with full thickness removal of the chest wall, the plane of the rib cage and/or the sternum was reconstructed using Vicryl mesh (n = 7), PTFE soft tissue patch (n = 11), marlex-mesh (n = 1), or methyl-methacrylate (n = 3). There was one case of hospital mortality, 6 weeks postoperatively, due to neurological failure from an independent preoperatively undiagnosed brain tumor. There were 4 reoperations: one early and one late (4 months) infection, one case of limited superficial necrosis of a flap and one with chronic lymphous drainage from a large myocutaneous flap. In no instance was primary postoperative ventilation therapy necessary. Mechanical ventilation was instituted only on day 8 in the patient who accounts for the mortality in this series. In the presence of primary infection, the greater omentum was used for the restoration of the integument.

  4. Designing a Sound Reducing Wall

    ERIC Educational Resources Information Center

    Erk, Kendra; Lumkes, John; Shambach, Jill; Braile, Larry; Brickler, Anne; Matthys, Anna

    2015-01-01

    Acoustical engineers use their knowledge of sound to design quiet environments (e.g., classrooms and libraries) as well as to design environments that are supposed to be loud (e.g., concert halls and football stadiums). They also design sound barriers, such as the walls along busy roadways that decrease the traffic noise heard by people in…

  5. Mirror, Mirror, on the Wall.

    ERIC Educational Resources Information Center

    Flowers, Jim; Rose, M. Annette

    1998-01-01

    Students use tables of anthropometric data, their own measurements, underlying principles of physics, and math to solve a problem. The problem is to determine the height of a wall mirror, and where to mount it, so that 90% of the clientele can view their entire length without stretching or bending. (Author)

  6. Wary Eyes Monitoring Wall Street

    ERIC Educational Resources Information Center

    Jacobson, Linda

    2008-01-01

    School business officials kept a close watch on the financial markets this week--and on district investment portfolios and teacher-retirement funds--as stock prices gyrated and once-sound institutions got government bailouts or crumbled into bankruptcy. While financial observers said it was too soon to predict how Wall Street's upheaval might…

  7. Cell wall construction in Saccharomyces cerevisiae.

    PubMed

    Klis, Frans M; Boorsma, Andre; De Groot, Piet W J

    2006-02-01

    In this review, we discuss new insights in cell wall architecture and cell wall construction in the ascomycetous yeast Saccharomyces cerevisiae. Transcriptional profiling studies combined with biochemical work have provided ample evidence that the cell wall is a highly adaptable organelle. In particular, the protein population that is anchored to the stress-bearing polysaccharides of the cell wall, and forms the interface with the outside world, is highly diverse. This diversity is believed to play an important role in adaptation of the cell to environmental conditions, in growth mode and in survival. Cell wall construction is tightly controlled and strictly coordinated with progression of the cell cycle. This is reflected in the usage of specific cell wall proteins during consecutive phases of the cell cycle and in the recent discovery of a cell wall integrity checkpoint. When the cell is challenged with stress conditions that affect the cell wall, a specific transcriptional response is observed that includes the general stress response, the cell wall integrity pathway and the calcineurin pathway. This salvage mechanism includes increased expression of putative cell wall assemblases and some potential cross-linking cell wall proteins, and crucial changes in cell wall architecture. We discuss some more enzymes involved in cell wall construction and also potential inhibitors of these enzymes. Finally, we use both biochemical and genomic data to infer that the architectural principles used by S. cerevisiae to build its cell wall are also used by many other ascomycetous yeasts and also by some mycelial ascomycetous fungi.

  8. The "clinics without walls" controversy.

    PubMed

    1993-08-01

    We began this article with the report from the Washington-based Health Care Advisory Board that "clinics without walls" are a "recipe for failure". But the analysis we've done indicates that the so-called "clinics without walls" may become the single most frequent format for new medical groups throughout the country. In some markets, hospitals and physicians simply don't have a viable alternative. The "clinic without walls" concept may just be a half-way house for fully integrated groups. If it is, then failures among "clinics without walls" should be viewed as simply failures of groups to gel. They shouldn't be viewed as the failure of a model for integration. In fact, any attempts by physicians to organize in our highly volatile industry should be viewed as a positive. The organizing physicians at least have a shot at survival and are not waiting to become casualties of managed care or healthcare reform. The variations in the three models we analyzed all seem to boil down to the extent the individual physician trades independent decision-making for the benefits of the larger group structure. In the adjacent table, we've attempted to highlight key issues and the decision-making authority in each of the three models. We've also suggested objectives that can be achieved when decision making authority is delegated by the physicians to a central board and management. Very clearly, it's important to address all of the issues in the table early in forming a "clinic without walls".(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Catalysts of plant cell wall loosening

    PubMed Central

    Cosgrove, Daniel J.

    2016-01-01

    The growing cell wall in plants has conflicting requirements to be strong enough to withstand the high tensile forces generated by cell turgor pressure while selectively yielding to those forces to induce wall stress relaxation, leading to water uptake and polymer movements underlying cell wall expansion. In this article, I review emerging concepts of plant primary cell wall structure, the nature of wall extensibility and the action of expansins, family-9 and -12 endoglucanases, family-16 xyloglucan endotransglycosylase/hydrolase (XTH), and pectin methylesterases, and offer a critical assessment of their wall-loosening activity PMID:26918182

  10. Direct calculation of wall interferences and wall adaptation for two-dimensional flow in wind tunnels with closed walls

    NASA Technical Reports Server (NTRS)

    Amecke, Juergen

    1986-01-01

    A method for the direct calculation of the wall induced interference velocity in two dimensional flow based on Cauchy's integral formula was derived. This one-step method allows the calculation of the residual corrections and the required wall adaptation for interference-free flow starting from the wall pressure distribution without any model representation. Demonstrated applications are given.

  11. A Near-Wall Reynolds-Stress Closure Without Wall Normals

    NASA Technical Reports Server (NTRS)

    Yuan, S. P.; So, R. M. C.

    1997-01-01

    Turbulent wall-bounded complex flows are commonly encountered in engineering practice and are of considerable interest in a variety of industrial applications. The presence of a wall significantly affects turbulence characteristics. In addition to the wall effects, turbulent wall-bounded flows become more complicated by the presence of additional body forces (e.g. centrifugal force and Coriolis force) and complex geometry. Most near-wall Reynolds stress models are developed from a high-Reynolds-number model which assumes turbulence is homogenous (or quasi-homogenous). Near-wall modifications are proposed to include wall effects in near-wall regions. In this process, wall normals are introduced. Good predictions could be obtained by Reynolds stress models with wall normals. However, ambiguity arises when the models are applied in flows with multiple walls. Many models have been proposed to model turbulent flows. Among them, Reynolds stress models, in which turbulent stresses are obtained by solving the Reynolds stress transport equations, have been proved to be the most successful ones. To apply the Reynolds stress models to wall-bounded flows, near-wall corrections accounting for the wall effects are needed, and the resulting models are called near-wall Reynolds stress models. In most of the existing near-wall models, the near-wall corrections invoke wall normals. These wall-dependent near-wall models are difficult to implement for turbulent flows with complex geometry and may give inaccurate predictions due to the ambiguity of wall normals at corners connecting multiple walls. The objective of this study is to develop a more general and flexible near-wall Reynolds stress model without using any wall-dependent variable for wall-bounded turbulent flows. With the aid of near-wall asymptotic analysis and results of direct numerical simulation, a new near-wall Reynolds stress model (NNWRS) is formulated based on Speziale et al.'s high-Reynolds-stress model with wall

  12. Microwave background distortions from domain walls

    NASA Technical Reports Server (NTRS)

    Goetz, Guenter; Noetzold, Dirk

    1990-01-01

    Domain walls arising in a cosmic phase transition after decoupling were recently proposed as seeds for the formation of large scale structure. The distortion induced in the microwave background radiation is calculated in dependence of the wall thickness, surface density, scalar field potential, cosmic redshift and the velocity of the wall. It was found that the maximal redshift distortion for both spherical and planar walls is of the order pi G sigma H(sup -1)(sub 0), where sigma is the surface energy density and H(sup -1)(sub 0) the Hubble parameter. It was also found that, for a wall thickness smaller than the horizon, walls can be treated as infinitely thin, i.e., the redshift distortion is independent of the wall thickness and the specific form of the scalar potential. For planar walls moving with a Lorentz-factor gamma the redshift distortion is enhanced by gamma cubed.

  13. Microwave background distortions from domain walls

    NASA Astrophysics Data System (ADS)

    Goetz, Guenter; Noetzold, Dirk

    1990-08-01

    Domain walls arising in a cosmic phase transition after decoupling were recently proposed as seeds for the formation of large scale structure. The distortion induced in the microwave background radiation is calculated in dependence of the wall thickness, surface density, scalar field potential, cosmic redshift and the velocity of the wall. It was found that the maximal redshift distortion for both spherical and planar walls is of the order pi G sigma H(sup -1)(sub 0), where sigma is the surface energy density and H(sup -1)(sub 0) the Hubble parameter. It was also found that, for a wall thickness smaller than the horizon, walls can be treated as infinitely thin, i.e., the redshift distortion is independent of the wall thickness and the specific form of the scalar potential. For planar walls moving with a Lorentz-factor gamma the redshift distortion is enhanced by gamma cubed.

  14. Microwave background distortions from domain walls.

    NASA Astrophysics Data System (ADS)

    Goetz, G.; Nötzold, D.

    1991-03-01

    Domain walls arising in a cosmic phase transition after decoupling were recently proposed as seeds for the formation of large-scale structure. The distortion induced in the microwave background radiation is calculated in dependence of the wall thickness, surface density, scalar field potential, cosmic redshift and the velocity of the wall. The authors find that the maximal redshift distortion for both spherical and planar walls is of the order πGσH0-1, where σ is the surface energy density and H0 the Hubble parameter. They also find that, for a wall thickness smaller than the horizon, walls can be treated as infinitely thin, i.e. the redshift distortion is independent of the wall thickness and the specific form of the scalar potential. For planar walls moving with a Lorentz-factor γ the redshift distortion is enhanced by γ3.

  15. Simulation of turbulent wall pressure

    NASA Technical Reports Server (NTRS)

    Ash, R. L.

    1978-01-01

    A Monte Carlo procedure was developed to simulate turbulent boundary layer wall pressure fluctuations. The approach utilizes much of the newly available conditional sampling information to construct the required distribution functions. Various disturbance wave forms were examined, as well as the effect of frequency-dependent decay. Good agreement between the simulation and experimental data was achieved for root mean square pressure level, power spectrum, and space time correlation.

  16. Breaching Walls in Urban Warfare

    DTIC Science & Technology

    1975-06-06

    Investigation reveals that a distinct need for a wall-breaching capability in infantry units does exist, and that current weapons and equipment readily...8217■ •• ABSTRACT 1 The process of urbanization throughout the world Is making urban warfare a major aspect of future military conflicts...exist, and that current weapons and equipment readily available to the infantry rifle company are inadequate for this purpose. Further examination

  17. How do plant cell walls extend?

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.

    1993-01-01

    This article briefly summarizes recent work that identifies the biophysical and biochemical processes that give rise to the extension of plant cell walls. I begin with the biophysical notion of stress relaxation of the wall and follow with recent studies of wall enzymes thought to catalyze wall extension and relaxation. Readers should refer to detailed reviews for more comprehensive discussion of earlier literature (Taiz, 1984; Carpita and Gibeaut, 1993; Cosgrove, 1993).

  18. Tube wall thickness measurement apparatus

    DOEpatents

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  19. Tube wall thickness measurement apparatus

    DOEpatents

    Lagasse, Paul R.

    1987-01-01

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  20. Through the wall solar cooker

    SciTech Connect

    Kerr, B.P.

    1987-04-07

    This patent describes a solar appliance for extending from the interior of a kitchen through an exterior wall of the building and beyond a predetermined distance in a cantilever manner to receive and concentrate in the appliance outside of the building, solar radiation rays for cooking purposes comprising: a housing, the housing being mounted to extend from a kitchen through an external wall of a building and beyond in a cantilever manner and forming a closed oven, the oven comprising a bottom, glass top, a pair of sides and a first end positioned with access from within the kitchen and comprising an oven door, a first reflective panel member mounted above, juxtapositioned to one edge of the glass top for positioning against the outer surface of the external wall and extending laterally therefrom for receiving and directing solar rays impinging thereon through the glass top and into the oven, and a second double-sided reflective panel mounted above and juxtapositioned to the glass top and extending substantially perpendicular to the first reflective panel for receiving solar rays impinging on either side thereof, and directing the solar rays into the oven.

  1. Neutron Probe of Building-Wall Composition

    NASA Technical Reports Server (NTRS)

    Trombka, J. I.; Evans, L. G.

    1984-01-01

    Walls of historic buildings charted by neutron radiography. Neutron source and Gamma-Ray Detector alined with each other yield map of composition of wall. Points spaced for minimal overlap based on mean free path of gamma rays emitted from wall materials. Map indicates nature and extent of changes in building materials so proper treatment is applied.

  2. Methods & Strategies: Put Your Walls to Work

    ERIC Educational Resources Information Center

    Jackson, Julie; Durham, Annie

    2016-01-01

    This column provides ideas and techniques to enhance your science teaching. This month's issue discusses planning and using interactive word walls to support science and reading instruction. Many classrooms have word walls displaying vocabulary that students have learned in class. Word walls serve as visual scaffolds to support instruction. To…

  3. Making Your Music Word Wall Work

    ERIC Educational Resources Information Center

    Leonhardt, Angela

    2011-01-01

    This article looks at what a word wall is and its use in the music classroom. The author outlines steps for creation of a word wall within the music classroom as well as the importance of such a resource. The author encourages the creation and consistent use of the word wall as leading to the development of stronger musicians and also independent,…

  4. Methods & Strategies: Put Your Walls to Work

    ERIC Educational Resources Information Center

    Jackson, Julie; Durham, Annie

    2016-01-01

    This column provides ideas and techniques to enhance your science teaching. This month's issue discusses planning and using interactive word walls to support science and reading instruction. Many classrooms have word walls displaying vocabulary that students have learned in class. Word walls serve as visual scaffolds to support instruction. To…

  5. 19. INTERIOR OF UTILITY ROOM SHOWING STUCCO WALL/DRYWALL WALL TRANSITION, ...

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

    19. INTERIOR OF UTILITY ROOM SHOWING STUCCO WALL/DRYWALL WALL TRANSITION, ELECTRICAL JUNCTION BOXES, BUILT-IN WALL CABINETRY, AND ELECTRICAL WALL HEATER. VIEW TO NORTHEAST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

  6. Fungal cell wall organization and biosynthesis.

    PubMed

    Free, Stephen J

    2013-01-01

    The composition and organization of the cell walls from Saccharomyces cerevisiae, Candida albicans, Aspergillus fumigatus, Schizosaccharomyces pombe, Neurospora crassa, and Cryptococcus neoformans are compared and contrasted. These cell walls contain chitin, chitosan, β-1,3-glucan, β-1,6-glucan, mixed β-1,3-/β-1,4-glucan, α-1,3-glucan, melanin, and glycoproteins as major constituents. A comparison of these cell walls shows that there is a great deal of variability in fungal cell wall composition and organization. However, in all cases, the cell wall components are cross-linked together to generate a cell wall matrix. The biosynthesis and properties of each of the major cell wall components are discussed. The chitin and glucans are synthesized and extruded into the cell wall space by plasma membrane-associated chitin synthases and glucan synthases. The glycoproteins are synthesized by ER-associated ribosomes and pass through the canonical secretory pathway. Over half of the major cell wall proteins are modified by the addition of a glycosylphosphatidylinositol anchor. The cell wall glycoproteins are also modified by the addition of O-linked oligosaccharides, and their N-linked oligosaccharides are extensively modified during their passage through the secretory pathway. These cell wall glycoprotein posttranslational modifications are essential for cross-linking the proteins into the cell wall matrix. Cross-linking the cell wall components together is essential for cell wall integrity. The activities of four groups of cross-linking enzymes are discussed. Cell wall proteins function as cross-linking enzymes, structural elements, adhesins, and environmental stress sensors and protect the cell from environmental changes. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Asymmetric counter propagation of domain walls

    NASA Astrophysics Data System (ADS)

    Andrade-Silva, I.; Clerc, M. G.; Odent, V.

    2016-07-01

    Far from equilibrium systems show different states and domain walls between them. These walls, depending on the type of connected equilibria, exhibit a rich spatiotemporal dynamics. Here, we investigate the asymmetrical counter propagation of domain walls in an in-plane-switching cell filled with a nematic liquid crystal. Experimentally, we characterize the shape and speed of the domain walls. Based on the molecular orientation, we infer that the counter propagative walls have different elastic deformations. These deformations are responsible of the asymmetric counter propagating fronts. Theoretically, based on symmetry arguments, we propose a simple bistable model under the influence of a nonlinear gradient, which qualitatively describes the observed dynamics.

  8. Management of Congenital Chest Wall Deformities

    PubMed Central

    Blanco, Felix C.; Elliott, Steven T.; Sandler, Anthony D.

    2011-01-01

    Congenital chest wall deformities are considered to be anomalies in chest wall growth. These can be categorized as either rib cage overgrowth or deformities related to inadequate growth (aplasia or dysplasia). Rib cage overgrowth leads to depression of the sternum (pectus excavatum) or protuberance of the sternum (pectus carinatum) and accounts for greater than 90% of congenital chest wall deformities. The remaining deformities are a result of inadequate growth. Evolution in the management of congenital chest wall deformities has made significant progress over the past 25 years. This article will review chest wall deformities and the current management strategies of these interesting anomalies. PMID:22294949

  9. Skyrmions from Instantons inside Domain Walls

    NASA Astrophysics Data System (ADS)

    Eto, Minoru; Nitta, Muneto; Ohashi, Keisuke; Tong, David

    2005-12-01

    Some years ago, Atiyah and Manton described a method to construct approximate Skyrmion solutions from Yang-Mills instantons. Here we present a dynamical realization of this construction using domain walls in a five-dimensional gauge theory. The non-Abelian gauge symmetry is broken in each vacuum but restored in the core of the domain wall, allowing instantons to nestle inside the wall. We show that the world volume dynamics of the wall is given by the Skyrme model, including the four-derivative term, and the instantons appear as domain wall Skyrmions.

  10. Experimental investigation of wall shock cancellation and reduction of wall interference in transonic testing

    NASA Technical Reports Server (NTRS)

    Ferri, A.; Roffe, G.

    1975-01-01

    A series of experiments were performed to evaluate the effectiveness of a three-dimensional land and groove wall geometry and a variable permeability distribution to reduce the interference produced by the porous walls of a supercritical transonic test section. The three-dimensional wall geometry was found to diffuse the pressure perturbations caused by small local mismatches in wall porosity permitting the use of a relatively coarse wall porosity control to reduce or eliminate wall interference effects. The wall porosity distribution required was found to be a sensitive function of Mach number requiring that the Mach number repeatability characteristics of the test apparatus be quite good. The effectiveness of a variable porosity wall is greatest in the upstream region of the test section where the pressure differences across the wall are largest. An effective variable porosity wall in the down stream region of the test section requires the use of a slightly convergent test section geometry.

  11. Mechanism of bubble detachment from vibrating walls

    SciTech Connect

    Kim, Dongjun; Park, Jun Kwon Kang, Kwan Hyoung; Kang, In Seok

    2013-11-15

    We discovered a previously unobserved mechanism by which air bubbles detach from vibrating walls in glasses containing water. Chaotic oscillation and subsequent water jets appeared when a wall vibrated at greater than a critical level. Wave forms were developed at water-air interface of the bubble by the wall vibration, and water jets were formed when sufficiently grown wave-curvatures were collapsing. Droplets were pinched off from the tip of jets and fell to the surface of the glass. When the solid-air interface at the bubble-wall attachment point was completely covered with water, the bubble detached from the wall. The water jets were mainly generated by subharmonic waves and were generated most vigorously when the wall vibrated at the volume resonant frequency of the bubble. Bubbles of specific size can be removed by adjusting the frequency of the wall's vibration.

  12. Chest wall reconstruction after extended resection

    PubMed Central

    Seder, Christopher W.

    2016-01-01

    Extensive chest wall resection and reconstruction is a challenging procedure that requires a multidisciplinary approach, including input from thoracic surgeons, plastic surgeons, neurosurgeons, and radiation oncologists. The primary goals of any chest wall reconstruction is to obliterate dead space, restore chest wall rigidity, preserve pulmonary mechanics, protect intrathoracic organs, provide soft tissue coverage, minimize deformity, and allow patients to receive adjuvant radiotherapy. Successful chest wall reconstruction requires the re-establishment of skeletal stability to prevent chest wall hernias, avoids thoracoplasty-like contraction of the operated side, protects underlying viscera, and maintain a cosmetically-acceptable appearance. After skeletal stability is established, full tissue coverage can be achieved using direct closure, skin grafts, local advancement flaps, pedicled myocutaneous flaps, or free flaps. This review examines the indications for chest wall reconstruction and describes techniques for establishment of chest wall rigidity and soft tissue coverage. PMID:27942408

  13. Generalized Wall Function for Complex Turbulent Flows

    NASA Technical Reports Server (NTRS)

    Shih, Tsan-Hsing; Povinelli, Louis A.; Liu, Nan-Suey; Chen, Kuo-Huey

    2000-01-01

    A generalized wall function was proposed by Shih et al., (1999). It accounts the effect of pressure gradients on the flow near the wall. Theory shows that the effect of pressure gradients on the flow in the inertial sublayer is very significant and the standard wall function should be replaced by a generalized wall function. Since the theory is also valid for boundary layer flows toward separation, the generalized wall function may be applied to complex turbulent flows with acceleration, deceleration, separation and recirculation. This paper is to verify the generalized wall function with numerical simulations for boundary layer flows with various adverse and favorable pressure gradients, including flows about to separate. Furthermore, a general procedure of implementation of the generalized wall function for National Combustion Code (NCC) is described, it can be applied to both structured and unstructured CFD codes.

  14. Near-wall serpentine cooled turbine airfoil

    DOEpatents

    Lee, Ching-Pang

    2013-09-17

    A serpentine coolant flow path (54A-54G) formed by inner walls (50, 52) in a cavity (49) between pressure and suction side walls (22, 24) of a turbine airfoil (20A). A coolant flow (58) enters (56) an end of the airfoil, flows into a span-wise channel (54A), then flows forward (54B) over the inner surface of the pressure side wall, then turns behind the leading edge (26), and flows back along a forward part of the suction side wall, then follows a loop (54E) forward and back around an inner wall (52), then flows along an intermediate part of the suction side wall, then flows into an aft channel (54G) between the pressure and suction side walls, then exits the trailing edge (28). This provides cooling matched to the heating topography of the airfoil, minimizes differential thermal expansion, revives the coolant, and minimizes the flow volume needed.

  15. Pulmonary complications of abdominal wall defects.

    PubMed

    Panitch, Howard B

    2015-01-01

    The abdominal wall is an integral component of the chest wall. Defects in the ventral abdominal wall alter respiratory mechanics and can impair diaphragm function. Congenital abdominal wall defects also are associated with abnormalities in lung growth and development that lead to pulmonary hypoplasia, pulmonary hypertension, and alterations in thoracic cage formation. Although infants with ventral abdominal wall defects can experience life-threatening pulmonary complications, older children typically experience a more benign respiratory course. Studies of lung and chest wall function in older children and adolescents with congenital abdominal wall defects are few; such investigations could provide strategies for improved respiratory performance, avoidance of respiratory morbidity, and enhanced exercise ability for these children.

  16. IMMUNOLOGICAL ROLE OF BRUCELLA ABORTUS CELL WALLS

    PubMed Central

    Foster, John W.; Ribi, Edgar

    1962-01-01

    Foster, John W. (University of Georgia, Athens) and Edgar Ribi. Immunological role of Brucella abortus cell walls. J. Bacteriol. 84:258–268. 1962—Cell walls and protoplasm were prepared from organisms disrupted in a refrigerated pressure cell. Cell walls were purified by sedimentation in a linear glycerol gradient. Antigens capable of protecting mice against infection with Brucella abortus and of reacting with antiserum prepared against whole cells were present chiefly in the cell wall; substances lethal to mice and responsible for primary inflammation of rabbit skin were also associated with the cell wall. Limited activity of protoplasm in these biological tests may or may not be due to contamination with cell-wall material. A substance extracted from whole cells with aqueous ether possessed an immunizing potency superior to that of killed whole cells or cell walls. Images PMID:13894243

  17. POROUS WALL, HOLLOW GLASS MICROSPHERES

    SciTech Connect

    Sexton, W.

    2012-06-30

    Hollow Glass Microspheres (HGM) is not a new technology. All one has to do is go to the internet and Google{trademark} HGM. Anyone can buy HGM and they have a wide variety of uses. HGM are usually between 1 to 100 microns in diameter, although their size can range from 100 nanometers to 5 millimeters in diameter. HGM are used as lightweight filler in composite materials such as syntactic foam and lightweight concrete. In 1968 a patent was issued to W. Beck of the 3M{trademark} Company for 'Glass Bubbles Prepared by Reheating Solid Glass Particles'. In 1983 P. Howell was issued a patent for 'Glass Bubbles of Increased Collapse Strength' and in 1988 H. Marshall was issued a patent for 'Glass Microbubbles'. Now Google{trademark}, Porous Wall, Hollow Glass Microspheres (PW-HGMs), the key words here are Porous Wall. Almost every article has its beginning with the research done at the Savannah River National Laboratory (SRNL). The Savannah River Site (SRS) where SRNL is located has a long and successful history of working with hydrogen and its isotopes for national security, energy, waste management and environmental remediation applications. This includes more than 30 years of experience developing, processing, and implementing special ceramics, including glasses for a variety of Department of Energy (DOE) missions. In the case of glasses, SRS and SRNL have been involved in both the science and engineering of vitreous or glass based systems. As a part of this glass experience and expertise, SRNL has developed a number of niches in the glass arena, one of which is the development of porous glass systems for a variety of applications. These porous glass systems include sol gel glasses, which include both xerogels and aerogels, as well as phase separated glass compositions, that can be subsequently treated to produce another unique type of porosity within the glass forms. The porous glasses can increase the surface area compared to 'normal glasses of a 1 to 2 order of

  18. Wall conditioning in JT-60

    NASA Astrophysics Data System (ADS)

    Arai, T.; Yamamoto, M.; Akino, N.; Kodama, K.; Nakamura, H.; Niikura, S.; Takatsu, H.; Shimizu, M.; Ohkubo, M.; Ohta, M.; JT-60 Team

    1987-02-01

    The vacuum vessel of JT-60 has a volume of 160 m 3 and a vacuum side surface of 2750 m 2 containing the surfaces of the first wall and many types of ports. The first wall is made of 20 μm TiC coated molybdenum and Inconel 625, bolted to the inner surface of the vacuum vessel. The vacuum vessel is evacuated with four identical pumping systems with a total pumping speed of 29 m 3/s for hydrogen. The wall conditioning procedure consisted of two wipes with special cloths wetted by freon after hot water and freon jet cleaning, and three bakeouts were carried out before the first plasma production. An ultimate pressure of 7.4 × 10 -7 Pa and an outgassing rate of 6.8 × 10 -10 Pa m 3/s m 2 were obtained. Low current pulse discharge cleaning (TDC) was carried out for two weeks at a vacuum vessel temperature of 200°C. The TDC is performed typically with a plasma current of 30 kA, a pulse duration of 40 ms, a repetition period in the range from 0.3 s to 1.2 s, a hydrogen pressure of 5.0 × 10 -3 Pa, and a toroidal field of 0.45 T. The TDC conditioning for 50 h removed a quantity of water vapor corresponding to approximately 0.3 g. The main residual gases consisting of hydrocarbons, were monitored in addition to hydrogen and carbon monoxide.

  19. Explosive Fragmentation of Dividing Walls

    DTIC Science & Technology

    1981-07-01

    bloc~ks and the complexity of the molds that would have to be built, it was de- cided to use full-scale masonry blocks. The walls fabricated were 163...Z .y ,. ,- ;. -.. "COMBINED DISTRIBUTION FOR TESI SERIES 3W I o3 10 ’ I • I ’ ii i’i’I l’l ’ I ’-I"* I *1" PiiPl’ ’ 1 ’l i l• iT -7,62 cm Rs

  20. First Wall and Operational Diagnostics

    SciTech Connect

    Lasnier, C; Allen, S; Boedo, J; Groth, M; Brooks, N; McLean, A; LaBombard, B; Sharpe, J; Skinner, C; Whyte, D; Rudakov, D; West, W; Wong, C

    2006-06-19

    In this chapter we review numerous diagnostics capable of measurements at or near the first wall, many of which contribute information useful for safe operation of a tokamak. There are sections discussing infrared cameras, visible and VUV cameras, pressure gauges and RGAs, Langmuir probes, thermocouples, and erosion and deposition measurements by insertable probes and quartz microbalance. Also discussed are dust measurements by electrostatic detectors, laser scattering, visible and IR cameras, and manual collection of samples after machine opening. In each case the diagnostic is discussed with a view toward application to a burning plasma machine such as ITER.

  1. Water Walls for Life Support

    NASA Technical Reports Server (NTRS)

    Flynn, Michael T. (Inventor); Gormly, Sherwin J. (Inventor); Hammoudeh, Mona (Inventor); Richardson, Tra-My Justine (Inventor)

    2017-01-01

    A method and associated system for processing waste gases, liquids and solids, produced by human activity, to separate (i) liquids suitable for processing to produce potable water, (ii) solids and liquids suitable for construction of walls suitable for enclosing a habitat volume and for radiation shielding, and (iii) other fluids and solids that are not suitable for processing. A forward osmosis process and a reverse osmosis process are sequentially combined to reduce fouling and to permit accumulation of different processable substances. The invention may be used for long term life support of human activity.

  2. Wall interference assessment and corrections

    NASA Technical Reports Server (NTRS)

    Newman, P. A.; Kemp, W. B., Jr.; Garriz, J. A.

    1989-01-01

    Wind tunnel wall interference assessment and correction (WIAC) concepts, applications, and typical results are discussed in terms of several nonlinear transonic codes and one panel method code developed for and being implemented at NASA-Langley. Contrasts between 2-D and 3-D transonic testing factors which affect WIAC procedures are illustrated using airfoil data from the 0.3 m Transonic Cryogenic Tunnel and Pathfinder 1 data from the National Transonic Facility. Initial results from the 3-D WIAC codes are encouraging; research on and implementation of WIAC concepts continue.

  3. Workshop on First Wall Coating

    NASA Astrophysics Data System (ADS)

    Kamada, K.; Fukutomi, M.

    1982-03-01

    Impurity control and first wall design in the JT 60 long pulse Tokamak is discussed. The present state of coating technology in Japan is reviewed with emphasis on fabrication methods and the characterization of thin coated films available by plasma spraying and chemical and physical vapor deposition. Surface preparation, radiation damage, internal stress, crystal structure and bonding are considered as well as the application of silicon carbide, titanium nitride, titanium carbide, titanium boride, and chromium nitride coatings by magnetron sputtering, long plating, electron beam evaporation, and gas absorption and reactive r.f. sputtering.

  4. Through-Wall Imaging Radar

    DTIC Science & Technology

    2012-01-01

    receiver dynamic range to be applied to the target scene behind the wall. A time-division multiplexed ( TDM ), multiple-input, multiple-output (MIMO...by the data-acquisition computer. The TDM MIMO radar system sequences through each of the 44 bistatic combinations, acquiring one range profile at...96 5. 75 5. 75 2 FiGurE 5. In this cartoon of the time-division multiplexed ( TDM ), multiple-input, multiple-output (MIMO) array lay- out [compare to

  5. An improved resistive wall monitor

    SciTech Connect

    Fellenz, Brian; Crisp, Jim

    1998-12-10

    Resistive wall monitors were designed and built for the Fermilab Main Injector project. These devices measure longitudinal beam current from 3 KHz to 4 GHz with a 1 ohm gap impedance. The new design provides a larger aperture and a calibration port to improve the accuracy of single-bunch intensity measurements. Microwave absorber material is used to reduce interference from spurious electromagnetic waves traveling inside the beam pipe. Several types of ferrite materials were evaluated for the absorber. Inexpensive ferrite rods were selected and assembled in an array forming the desired geometry without machining.

  6. Moving walls and geometric phases

    NASA Astrophysics Data System (ADS)

    Facchi, Paolo; Garnero, Giancarlo; Marmo, Giuseppe; Samuel, Joseph

    2016-09-01

    We unveil the existence of a non-trivial Berry phase associated to the dynamics of a quantum particle in a one dimensional box with moving walls. It is shown that a suitable choice of boundary conditions has to be made in order to preserve unitarity. For these boundary conditions we compute explicitly the geometric phase two-form on the parameter space. The unboundedness of the Hamiltonian describing the system leads to a natural prescription of renormalization for divergent contributions arising from the boundary.

  7. Spontaneous Behaviors and Wall-Curvature Lead to Apparent Wall Preference in Planarian.

    PubMed

    Akiyama, Yoshitaro; Agata, Kiyokazu; Inoue, Takeshi

    2015-01-01

    The planarian Dugesia japonica tends to stay near the walls of its breeding containers and experimental dishes in the laboratory, a phenomenon called "wall preference". This behavior is thought to be important for environmental adaptation, such as hiding by planarians in nature. However, the mechanisms regulating wall-preference behavior are not well understood, since this behavior occurs in the absence of any particular stimulation. Here we show the mechanisms of wall-preference behavior. Surprisingly, planarian wall-preference behavior was also shown even by the head alone and by headless planarians. These results indicate that planarian "wall-preference" behavior only appears to be a "preference" behavior, and is actually an outcome of spontaneous behaviors, rather than of brain function. We found that in the absence of environmental cues planarians moved basically straight ahead until they reached a wall, and that after reaching a wall, they changed their direction of movement to one tangential to the wall, suggesting that this spontaneous behavior may play a critical role in the wall preference. When we tested another spontaneous behavior, the wigwag movement of the planarian head, using computer simulation with various wigwag angles and wigwag intervals, large wigwag angle and short wigwag interval reduced wall-preference behavior. This indicated that wigwag movement may determine the probability of staying near the wall or leaving the wall. Furthermore, in accord with this simulation, when we tested planarian wall-preference behavior using several assay fields with different curvature of the wall, we found that concavity and sharp curvature of walls negatively impacted wall preference by affecting the permissible angle of the wigwag movement. Together, these results indicate that planarian wall preference may be involuntarily caused by the combination of two spontaneous planarian behaviors: moving straight ahead until reaching a wall and then moving along it

  8. Spontaneous Behaviors and Wall-Curvature Lead to Apparent Wall Preference in Planarian

    PubMed Central

    Akiyama, Yoshitaro; Agata, Kiyokazu; Inoue, Takeshi

    2015-01-01

    The planarian Dugesia japonica tends to stay near the walls of its breeding containers and experimental dishes in the laboratory, a phenomenon called “wall preference”. This behavior is thought to be important for environmental adaptation, such as hiding by planarians in nature. However, the mechanisms regulating wall-preference behavior are not well understood, since this behavior occurs in the absence of any particular stimulation. Here we show the mechanisms of wall-preference behavior. Surprisingly, planarian wall-preference behavior was also shown even by the head alone and by headless planarians. These results indicate that planarian “wall-preference” behavior only appears to be a “preference” behavior, and is actually an outcome of spontaneous behaviors, rather than of brain function. We found that in the absence of environmental cues planarians moved basically straight ahead until they reached a wall, and that after reaching a wall, they changed their direction of movement to one tangential to the wall, suggesting that this spontaneous behavior may play a critical role in the wall preference. When we tested another spontaneous behavior, the wigwag movement of the planarian head, using computer simulation with various wigwag angles and wigwag intervals, large wigwag angle and short wigwag interval reduced wall-preference behavior. This indicated that wigwag movement may determine the probability of staying near the wall or leaving the wall. Furthermore, in accord with this simulation, when we tested planarian wall-preference behavior using several assay fields with different curvature of the wall, we found that concavity and sharp curvature of walls negatively impacted wall preference by affecting the permissible angle of the wigwag movement. Together, these results indicate that planarian wall preference may be involuntarily caused by the combination of two spontaneous planarian behaviors: moving straight ahead until reaching a wall and then

  9. Speech About the Great Wall

    NASA Astrophysics Data System (ADS)

    Yang, Chen Ning

    2013-05-01

    Of all the sights that I saw during that trip, the one that provoked the most thought on my part was the Great Wall. The Great Wall defies imagination. It is simple and strong. It winds gracefully up and down. It scales slowly but steadily the distant hill, to disappear down into the valley beyond, only to climb again, inexorably, to surmount the next mountain in its path. As one examines the individual stones with which it was built, one realizes how much sweat and blood there must have been in its complex history. As one looks at the overall structure, at its strength and elegance, its real significance begins to emerge. It is long. It is tenacious. It is flexible in every turn, but is persistent and persisting in the long range development. Its overall unity of purpose is what gives it strength and character. And its overall unity of purpose is what makes it one of the man-made structures on the surface of the earth to become first visible to a visitor approaching our planet from outer space...

  10. [Ageing of the arterial wall].

    PubMed

    Hanon, O

    2006-11-01

    Several mechanisms are implicated in the arterial wall changes due to ageing: ageing, hypertension and atherosclerosis. Although the changes related to ageing (arteriosclerosis) have many factors in common with those induced by hypertension, they differ from those caused by atherosclerosis although commonly associated. Arteriosclerosis causes a diffuse increase of the rigidity of the large arteries by disease of the media, the main clinical manifestation of which is the increase in pulsed pressure. This arterial "hyperpulsability" contributes to a defect in coupling between the heart and the blood vessels which results in an increase in the pulsatile load of the left ventricle and to left ventricular hypertrophy and decreased coronary perfusion. Atherosclerosis seems more of a localised scarring phenomenon of the arterial wall which is exposed to a series of chronic aggressions characterised by deposits of lipids in the intima and whose main complication is thrombosis. Although these two processes may be associated, or interact one with the other, they are clearly different in nature. Therefore, atherosclerosis is a localised disease resulting in a decrease in arterial lumen, quite different from arteriosclerosis which is a diffuse, physiological condition which leads to an increase in the arterial lumen.

  11. SRNL POROUS WALL GLASS MICROSPHERES

    SciTech Connect

    Wicks, G; Leung Heung, L; Ray Schumacher, R

    2008-04-15

    The Savannah River National Laboratory (SRNL) has developed a new medium for storage of hydrogen and other gases. This involves fabrication of thin, Porous Walled, Hollow Glass Microspheres (PW-HGMs), with diameters generally in the range of 1 to several hundred microns. What is unique about the glass microballons is that porosity has been induced and controlled within the thin, one micron thick walls, on the scale of 10 to several thousand Angstroms. This porosity results in interesting properties including the ability to use these channels to fill the microballons with special absorbents and other materials, thus providing a contained environment even for reactive species. Gases can now enter the microspheres and be retained on the absorbents, resulting in solid-state and contained storage of even reactive species. Also, the porosity can be altered and controlled in various ways, and even used to filter mixed gas streams within a system. SRNL is involved in about a half dozen different programs involving these PW-HGMs and an overview of some of these activities and results emerging are presented.

  12. Tube wall temperature monitoring technique

    SciTech Connect

    Granton, R.L.

    1985-07-01

    In 1977, Monsanto and Conoco undertook the construction of a new, modern technology ethylene plant at Chocolate Bayou, near Alvin, Texas. This plant included high severity cracking furnaces with potential tube wall temperatures considerably higher than any we had previously experienced. Furnace on-stream time between decokes, a factor in the economics of plant operation, was limited by tube wall temperature, thus requiring its accurate knowledge. Earlier work with other ethylene furnaces had also demonstrated our lack of knowledge concerning high temperature measurements in a furnace firebox environment. This had to change. An outside consultant was called upon to provide a threeday workshop on radiant tube temperature sensing. The workshop consisted of two days of formal training in the theory and practice of temperature measurement and one day of field training. This workshop was conducted at a site away from the plant. Approximately 20 engineers (manufacturing and technical groups) attended. The major topics covered by this workshop are as follows: radiant tube temperature sensing, radiation situation of radiant tubes, g.a. method: sample calculations, noncontact sensors: methods of specifying and purchasing, thermal imager strategies, calibration of noncontact sensors, avoiding problems with noncontact sensors, optical aids to radiant tube viewing, tube temperature management and its environmental implications, and contact temperature sensors.

  13. Reinforcing masonry walls with composite materials

    NASA Astrophysics Data System (ADS)

    Jai, John Chia-Han

    1999-10-01

    In this investigation, a procedure is developed for determining the effectiveness of composite materials in retrofitting masonry buildings to reduce seismic damage. The reinforcement considered is a thin layer of fiber-reinforced composite applied to the wall in a wallpaper-like fashion. Models were developed which predicts the behavior of masonry walls reinforced in such a fashion and subjected to static, in-plane normal and shear loads. Solid walls, as well as walls with openings (such as windows and doors), were considered. The models estimate the load-deflection characteristic of the wall, the load set at which the wall fails, and the deflection of the wall at the instant of failure. The models were verified by tests performed with walls constructed of clay bricks and mortar, and with walls made of wood bricks. In these tests, the load versus deflection, the failure load, and the failure deflection were measured. Reasonable agreements were found between the values calculated by the models and the data. Parametric studies were also performed. The results of these studies indicate that composite reinforcement applied in a wallpaper-like fashion may increase substantially the load carrying capacities of masonry walls.

  14. Moss cell walls: structure and biosynthesis

    PubMed Central

    Roberts, Alison W.; Roberts, Eric M.; Haigler, Candace H.

    2012-01-01

    The genome sequence of the moss Physcomitrella patens has stimulated new research examining the cell wall polysaccharides of mosses and the glycosyl transferases that synthesize them as a means to understand fundamental processes of cell wall biosynthesis and plant cell wall evolution. The cell walls of mosses and vascular plants are composed of the same classes of polysaccharides, but with differences in side chain composition and structure. Similarly, the genomes of P. patens and angiosperms encode the same families of cell wall glycosyl transferases, yet, in many cases these families have diversified independently in each lineage. Our understanding of land plant evolution could be enhanced by more complete knowledge of the relationships among glycosyl transferase functional diversification, cell wall structural and biochemical specialization, and the roles of cell walls in plant adaptation. As a foundation for these studies, we review the features of P. patens as an experimental system, analyses of cell wall composition in various moss species, recent studies that elucidate the structure and biosynthesis of cell wall polysaccharides in P. patens, and phylogenetic analysis of P. patens genes potentially involved in cell wall biosynthesis. PMID:22833752

  15. The State of the GeoWall

    NASA Astrophysics Data System (ADS)

    Morin, P. J.; Leigh, J.; van Keken, P.; Johnson, A.

    2003-12-01

    The GeoWall stereo projection technology has been widely adopted within Earth Science. Over 20,000 undergraduate students per year use a GeoWall in classroom and lab settings at over 80 institutions around the world using over 200 GeoWalls. We believe that critical mass for this technology has been reached in the Earth Science. Many collaborations have been initiated. With Iris, GeoWall is exploring new ways to monitor seismic networks in real-time and to visualize extremely large, whole Earth seismic simulations. We are also working with a number of drilling organizations including JOI, DOSECC and LacCore to bring modern visualization technology to core interpretation and drill site selection. Also, over 15 museums now have or are building GeoWalls for informal education. Much of the science that is being performed on the GeoWall is finding its way directly into the classroom and science museum. One of the success stories has been the GeoWall Consortium's interaction with industry. The basic hardware for the GeoWall has been spun off to companies that now sell variations of the hardware. In addition, many software companies including ESRI and Dynamic Graphics have added support for the GeoWall in their products. The future of GeoWall is four fold. Curriculum development will bring more material to all GeoWall users. Assessment of the curriculum and educational psychology will give us GeoWall best practices. In technology development, the GeoWall 2 is a 20+ million pixel, tiled display which brings more resolution to the Earth Sciences than ever. To support research the consortium is developing a volume rendering application to visualize extremely large datasets.

  16. Immersion Refractometry of Isolated Bacterial Cell Walls

    PubMed Central

    Marquis, Robert E.

    1973-01-01

    Immersion-refractometric and light-scattering measurements were adapted to determinations of average refractive indices and physical compactness of isolated bacterial cell walls. The structures were immersed in solutions containing various concentrations of polymer molecules that cannot penetrate into wall pores, and then an estimate was made of the polymer concentration or the refractive index of the polymer solution in which light scattering was reduced to zero. Because each wall preparation was heterogeneous, the refractive index of the medium for zero light scattering had to be estimated by extrapolation. Refractive indices for walls suspended in bovine serum albumin solutions ranged from 1.348 for walls of the rod form of Arthrobacter crystallopoietes to 1.382 for walls of the teichoic acid deficient, 52A5 strain of Staphylococcus aureus. These indices were used to calculate approximate values for solids content per milliliter, and the calculated values agreed closely with those estimated from a knowledge of dextran-impermeable volumes per gram, dry weight, of the walls. When large molecules such as dextrans or serum albumin were used for immersion refractometry, the refractive indices obtained were for entire walls, including both wall polymers and wall water. When smaller molecules that can penetrate wall pores to various extents were used with Micrococcus lysodeikticus walls, the average, apparent refractive index of the structures increased as the molecular size of probing molecules was decreased. It was possible to obtain an estimate of 1.45 to 1.46 for the refractive index of wall polymers, predominantly peptidoglycans in this case, by extrapolating the curve for refractive index versus molecular radius to a value of 0.2 nm, the approximate radius of a water molecule. This relatively low value for polymer refractive index was interpreted as evidence in favor of the amorphous, elastic model of peptidoglycan structure and against the crystalline, rigid

  17. Architecture of dermatophyte cell Walls: Electron microscopic and biochemical analysis

    NASA Technical Reports Server (NTRS)

    Nozawa, Y.; Kitajima, Y.

    1984-01-01

    A review with 83 references on the cell wall structure of dermatophytes is presented. Topics discussed include separation and preparation of cell walls; microstructure of cell walls by electron microscopy; chemical composition of cell walls; structural model of cell walls; and morphological structure of cell walls.

  18. Near wall flow parameters in the blade end-wall corner region

    NASA Astrophysics Data System (ADS)

    Bhargava, R. K.; Raj, R.

    The effects of secondary end-wall corner flows on near wall flow parameters in turbomachinary are studied. Important near wall flow parameters such as the wall shear stress vector, the mean wall pressure, the wall pressure fluctuations, and the correlation of the wall pressure fluctuation with the velocity fluctuation in three-dimensional turbulent flows are first experimentally investigated. The blade end-wall corner region is simulated by mounting airfoil section of symmetric blades on both sides of the flat plate with semicircular leading edge. Observed changes in the maximum values of the wall shear stress and its location from the corner line could be associated with the streching and attenuation of the horseshoe vortex. The values of wall pressure fluctuation intensity in the blade end-wall corner region are found to be influenced by the changes of the strength of the horseshoe vortex. The correlation of the wall pressure fluctuation with the velocity fluctuation indicated higher values of correlation coefficient in the inner region as compared to the outer region of the shear layer. The values of wall pressure-velocity correlation coefficient in the blade end-wall corner region also decrease in the streamwise direction while increasing in the presence of favorable and adverse pressure gradients.

  19. Near wall flow parameters in the blade end-wall corner region

    NASA Technical Reports Server (NTRS)

    Bhargava, R. K.; Raj, R.

    1989-01-01

    The effects of secondary end-wall corner flows on near wall flow parameters in turbomachinary are studied. Important near wall flow parameters such as the wall shear stress vector, the mean wall pressure, the wall pressure fluctuations, and the correlation of the wall pressure fluctuation with the velocity fluctuation in three-dimensional turbulent flows are first experimentally investigated. The blade end-wall corner region is simulated by mounting airfoil section of symmetric blades on both sides of the flat plate with semicircular leading edge. Observed changes in the maximum values of the wall shear stress and its location from the corner line could be associated with the streching and attenuation of the horseshoe vortex. The values of wall pressure fluctuation intensity in the blade end-wall corner region are found to be influenced by the changes of the strength of the horseshoe vortex. The correlation of the wall pressure fluctuation with the velocity fluctuation indicated higher values of correlation coefficient in the inner region as compared to the outer region of the shear layer. The values of wall pressure-velocity correlation coefficient in the blade end-wall corner region also decrease in the streamwise direction while increasing in the presence of favorable and adverse pressure gradients.

  20. Cell Wall Assembly in Fucus Zygotes

    PubMed Central

    Quatrano, Ralph S.; Stevens, Patricia T.

    1976-01-01

    Fertilization triggers the assembly of a cell wall around the egg cell of three brown algae, Fucus vesiculosus, F. distichus, and F. inflatus. New polysaccharide polymers are continually being added to the cell wall during the first 24 hours of synchronous embryo development. This wall assembly involves the extracellular deposition of fibrillar material by cytoplasmic vesicles fusing with the plasma membrane. One hour after fertilization a fragmented wall can be isolated free of cytoplasm and contains equal amounts of cellulose and alginic acid with no fucose-containing polymers (fucans) present. Birefringence of the wall caused by oriented cellulose microfibrils is not detected in all zygotes until 4 hours, at which time intact cell walls can be isolated that retain the shape of the zygote. These walls have a relatively low ratio of fucose to xylose and little sulfate when compared to walls from older embryos. When extracts of walls from 4-hour zygotes are subjected to cellulose acetate electrophoresis at pH 7, a single fucan (F1) can be detected. By 12 hours, purified cell walls are composed of fucans containing a relatively high ratio of fucose to xylose and high levels of sulfate, and contain a second fucan (F2) which is electrophoretically distinct from F1. F2 appears to be deposited in only a localized region of the wall, that which elongates to form the rhizoid cell. Throughout wall assembly, the polyuronide block co-polymer alginic acid did not significantly vary its mannuronic (M) to guluronic (G) acid ratio (0.33-0.55) or its block distribution (MG, 54%; GG, 30%; MM, 16%). From 6 to 24 hours of embryo development, the proportion of the major polysaccharide components found in purified walls is stable. Alginic acid is the major polymer and comprises about 60% of the total wall, while cellulose and the fucans each make-up about 20% of the remainder. During the extracellular assembly of this wall, the intracellular levels of the storage glucan laminaran

  1. Wall Interference Study of the NTF Slotted Tunnel Using Bodies of Revolution Wall Signature Data

    NASA Technical Reports Server (NTRS)

    Iyer, Venkit; Kuhl, David D.; Walker, Eric L.

    2004-01-01

    This paper is a description of the analysis of blockage corrections for bodies of revolution for the slotted-wall configuration of the National Transonic Facility (NTF) at the NASA Langley Research Center (LaRC). A wall correction method based on the measured wall signature is used. Test data from three different-sized blockage bodies and four wall ventilation settings were analyzed at various Mach numbers and unit Reynolds numbers. The results indicate that with the proper selection of the boundary condition parameters, the wall correction method can predict blockage corrections consistent with the wall measurements for Mach numbers as high as 0.95.

  2. Seismic behavior of geogrid reinforced slag wall

    SciTech Connect

    Edincliler, Ayse; Baykal, Gokhan; Saygili, Altug

    2008-07-08

    Flexible retaining structures are known with their high performance under earthquake loads. In geogrid reinforced walls the performance of the fill material and the interface of the fill and geogrid controls the performance. Geosynthetic reinforced walls in seismic regions must be safe against not only static forces but also seismic forces. The objective of this study is to determine the behavior of a geogrid reinforced slag wall during earthquake by using shaking table experiments. This study is composed of three stages. In the first stage the physical properties of the material to be used were determined. In the second part, a case history involving the use of slag from steel industry in the construction of geogrid reinforced wall is presented. In the third stage, the results of shaking table tests conducted using model geogrid wall with slag are given. From the results, it is seen that slag can be used as fill material for geogrid reinforced walls subjected to earthquake loads.

  3. Secondary cell walls: biosynthesis and manipulation.

    PubMed

    Kumar, Manoj; Campbell, Liam; Turner, Simon

    2016-01-01

    Secondary cell walls (SCWs) are produced by specialized plant cell types, and are particularly important in those cells providing mechanical support or involved in water transport. As the main constituent of plant biomass, secondary cell walls are central to attempts to generate second-generation biofuels. Partly as a consequence of this renewed economic importance, excellent progress has been made in understanding how cell wall components are synthesized. SCWs are largely composed of three main polymers: cellulose, hemicellulose, and lignin. In this review, we will attempt to highlight the most recent progress in understanding the biosynthetic pathways for secondary cell wall components, how these pathways are regulated, and how this knowledge may be exploited to improve cell wall properties that facilitate breakdown without compromising plant growth and productivity. While knowledge of individual components in the pathway has improved dramatically, how they function together to make the final polymers and how these individual polymers are incorporated into the wall remain less well understood.

  4. Collective magnetism at multiferroic vortex domain walls.

    PubMed

    Geng, Yanan; Lee, N; Choi, Y J; Cheong, S-W; Wu, Weida

    2012-12-12

    Cross-coupled phenomena of multiferroic domains and domain walls are of fundamental scientific and technological interest. Using cryogenic magnetic force microscopy, we find alternating net magnetic moments at ferroelectric domain walls around vortex cores in multiferroic hexagonal ErMnO(3), which correlate with each other throughout the entire vortex network. This collective nature of domain wall magnetism originates from the uncompensated Er(3+) moments at domain walls and the self-organization of the vortex network. Our results demonstrate that the collective domain wall magnetism can be controlled by external magnetic fields and represent a major advancement in the manipulation of local magnetic moments by harnessing cross-coupled domain walls.

  5. Panelized wall system with foam core insulation

    DOEpatents

    Kosny, Jan [Oak Ridge, TN; Gaskin, Sally [Houston, TX

    2009-10-20

    A wall system includes a plurality of wall members, the wall members having a first metal panel, a second metal panel, and an insulating core between the first panel and the second panel. At least one of the first panel and the second panel include ridge portions. The insulating core can be a foam, such as a polyurethane foam. The foam can include at least one opacifier to improve the k-factor of the foam.

  6. Electron-wall Interaction in Hall Thrusters

    SciTech Connect

    Y. Raitses; D. Staack; M. Keidar; N.J. Fisch

    2005-02-11

    Electron-wall interaction effects in Hall thrusters are studied through measurements of the plasma response to variations of the thruster channel width and the discharge voltage. The discharge voltage threshold is shown to separate two thruster regimes. Below this threshold, the electron energy gain is constant in the acceleration region and therefore, secondary electron emission (SEE) from the channel walls is insufficient to enhance electron energy losses at the channel walls. Above this voltage threshold, the maximum electron temperature saturates.

  7. First wall for polarized fusion reactors

    DOEpatents

    Greenside, Henry S.; Budny, Robert V.; Post, Jr., Douglass E.

    1988-01-01

    Depolarization mechanisms arising from the recycling of the polarized fuel at the limiter and the first-wall of a fusion reactor are greater than those mechanisms in the plasma. Rapid depolarization of the plasma is prevented by providing a first-wall or first-wall coating formed of a low-Z, non-metallic material having a depolarization rate greater than 1 sec.sup.-1.

  8. Blunt traumatic abdominal wall disruption with evisceration

    PubMed Central

    McDaniel, Ellen; Stawicki, Stanislaw PA; Bahner, David P

    2011-01-01

    Blunt traumatic abdominal wall disruptions associated with evisceration are very rare. The authors describe a case of traumatic abdominal wall disruption with bowel evisceration that occurred after a middle-aged woman sustained direct focal blunt force impact to the lower abdomen. Abdominal exploration and surgical repair of the abdominal wall defect were performed, with good clinical outcome. A brief overview of literature pertinent to this rare trauma scenario is presented. PMID:22229144

  9. Textural break foundation wall construction modules

    DOEpatents

    Phillips, Steven J.

    1990-01-01

    Below-grade, textural-break foundation wall structures are provided for inhibiting diffusion and advection of liquids and gases into and out from a surrounding hydrogeologic environment. The foundation wall structure includes a foundation wall having an interior and exterior surface and a porous medium disposed around a portion of the exterior surface. The structure further includes a modular barrier disposed around a portion of the porous medium. The modular barrier is substantially removable from the hydrogeologic environment.

  10. Virtual gap dielectric wall accelerator

    DOEpatents

    Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

    2013-11-05

    A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

  11. Beetle Kill Wall at NREL

    ScienceCinema

    None

    2016-07-12

    When it comes to designing an interior decorative feature for one of the most energy efficient office buildings in the world, very few would consider bringing in a beetle to do the job. But thats what happened at the U.S. Department of Energy's (DOE) Research Support Facility (RSF) located on the National Renewable Energy Laboratory (NREL) campus.In June, the RSF will become home to more than 800 workers from DOE and NREL and building visitors will be greeted with a soaring, two-story high wall entirely covered with wood harvested from the bark beetle infestation that has killed millions of pine trees in the Western U.S. But, the use of beetle kill wood is just one example of the resources being leveraged to make the RSF a model for sustainability and one more step toward NRELs goal to be a net zero energy campus.

  12. Along Endurance Crater's Inner Wall

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This view from the base of 'Burns Cliff' in the inner wall of 'Endurance Crater' combines several frames taken by Opportunity's navigation camera during the NASA rover's 280th martian day (Nov. 6, 2004). It is presented in a cylindrical projection with geometric seam correction. The cliff dominates the left and right portions of the image, while the central portion looks down into the crater. The 'U' shape of this mosaic results from the rover's tilt of about 30 degrees on the sloped ground below the cliff. Rover wheel tracks in the left half of the image show some of the slippage the rover experienced in making its way to this point. The site from which this image was taken has been designated as Opportunity's Site 37.

  13. Plant cell walls to ethanol.

    PubMed

    Jordan, Douglas B; Bowman, Michael J; Braker, Jay D; Dien, Bruce S; Hector, Ronald E; Lee, Charles C; Mertens, Jeffrey A; Wagschal, Kurt

    2012-03-01

    Conversion of plant cell walls to ethanol constitutes second generation bioethanol production. The process consists of several steps: biomass selection/genetic modification, physiochemical pretreatment, enzymatic saccharification, fermentation and separation. Ultimately, it is desirable to combine as many of the biochemical steps as possible in a single organism to achieve CBP (consolidated bioprocessing). A commercially ready CBP organism is currently unreported. Production of second generation bioethanol is hindered by economics, particularly in the cost of pretreatment (including waste management and solvent recovery), the cost of saccharification enzymes (particularly exocellulases and endocellulases displaying kcat ~1 s-1 on crystalline cellulose), and the inefficiency of co-fermentation of 5- and 6-carbon monosaccharides (owing in part to redox cofactor imbalances in Saccharomyces cerevisiae).

  14. Wall-crossing made smooth

    NASA Astrophysics Data System (ADS)

    Pioline, Boris

    2015-04-01

    In D = 4 , theories on , the index receives contributions not only from single-particle BPS states, counted by the BPS indices, but also from multi-particle states made of BPS constituents. In a recent work [1], a general formula expressing the index in terms of the BPS indices was proposed, which is smooth across walls of marginal stability and reproduces the expected single-particle contributions. In this note, I analyze the two-particle contributions predicted by this formula, and show agreement with the spectral asymmetry of the continuum of scattering states in the supersymmetric quantum mechanics of two non-relativistic, mutually non-local dyons. This may provide a physical justification for the error function profile used in the mathematics literature on indefinite theta series, and in the physics literature on black hole partition functions.

  15. Beetle Kill Wall at NREL

    SciTech Connect

    2010-01-01

    When it comes to designing an interior decorative feature for one of the most energy efficient office buildings in the world, very few would consider bringing in a beetle to do the job. But thats what happened at the U.S. Department of Energy's (DOE) Research Support Facility (RSF) located on the National Renewable Energy Laboratory (NREL) campus.In June, the RSF will become home to more than 800 workers from DOE and NREL and building visitors will be greeted with a soaring, two-story high wall entirely covered with wood harvested from the bark beetle infestation that has killed millions of pine trees in the Western U.S. But, the use of beetle kill wood is just one example of the resources being leveraged to make the RSF a model for sustainability and one more step toward NRELs goal to be a net zero energy campus.

  16. A Near-Wall Reynolds-Stress Closure without Wall Normals

    NASA Technical Reports Server (NTRS)

    Yuan, S. P.; So, R. M. C.

    1997-01-01

    With the aid of near-wall asymptotic analysis and results of direct numerical simulation, a new near-wall Reynolds stress model (NNWRS) is formulated based on the SSG high-Reynolds-stress model with wall-independent near-wall corrections. Only one damping function is used for flows with a wide range of Reynolds numbers to ensure that the near-wall modifications diminish away from the walls. The model is able to reproduce complicated flow phenomena induced by complex geometry, such as flow recirculation, reattachment and boundary-layer redevelopment in backward-facing step flow and secondary flow in three-dimensional square duct flow. In simple flows, including fully developed channel/pipe flow, Couette flow and boundary-layer flow, the wall effects are dominant, and the NNWRS model predicts less degree of turbulent anisotropy in the near-wall region compared with a wall-dependent near-wall Reynolds Stress model (NWRS) developed by So and colleagues. The comparison of the predictions given by the two models rectifies the misconception that the overshooting of skin friction coefficient in backward-facing step flow prevalent in those near-wall, models with wall normal is caused by he use of wall normal.

  17. Mechanics of the Toxoplasma gondii oocyst wall

    PubMed Central

    Dumètre, Aurélien; Dubey, Jitender P.; Ferguson, David J. P.; Bongrand, Pierre; Azas, Nadine; Puech, Pierre-Henri

    2013-01-01

    The ability of microorganisms to survive under extreme conditions is closely related to the physicochemical properties of their wall. In the ubiquitous protozoan parasite Toxoplasma gondii, the oocyst stage possesses a bilayered wall that protects the dormant but potentially infective parasites from harsh environmental conditions until their ingestion by the host. None of the common disinfectants are effective in killing the parasite because the oocyst wall acts as a primary barrier to physical and chemical attacks. Here, we address the structure and chemistry of the wall of the T. gondii oocyst by combining wall surface treatments, fluorescence imaging, EM, and measurements of its mechanical characteristics by using atomic force microscopy. Elasticity and indentation measurements indicated that the oocyst wall resembles common plastic materials, based on the Young moduli, E, evaluated by atomic force microscopy. Our study demonstrates that the inner layer is as robust as the bilayered wall itself. Besides wall mechanics, our results suggest important differences regarding the nonspecific adhesive properties of each layer. All together, these findings suggest a key biological role for the oocyst wall mechanics in maintaining the integrity of the T. gondii oocysts in the environment or after exposure to disinfectants, and therefore their potential infectivity to humans and animals. PMID:23798399

  18. Pollen wall development in flowering plants.

    PubMed

    Blackmore, Stephen; Wortley, Alexandra H; Skvarla, John J; Rowley, John R

    2007-01-01

    The outer pollen wall, or exine, is more structurally complex than any other plant cell wall, comprising several distinct layers, each with its own organizational pattern. Since elucidation of the basic events of pollen wall ontogeny using electron microscopy in the 1970s, knowledge of their developmental genetics has increased enormously. However, self-assembly processes that are not under direct genetic control also play an important role in pollen wall patterning. This review integrates ultrastructural and developmental findings with recent models for self-assembly in an attempt to understand the origins of the morphological complexity and diversity that underpin the science of palynology.

  19. Relevant surgical anatomy of the chest wall.

    PubMed

    Naidu, Babu V; Rajesh, Pala B

    2010-11-01

    The chest wall, like other regional anatomy, is a remarkable fusion of form and function. Principal functions are the protection of internal viscera and an expandable cylinder facilitating variable gas flow into the lungs. Knowledge of the anatomy of the whole cylinder (ribs, sternum, vertebra, diaphragm, intercostal spaces, and extrathoracic muscles) is therefore not only important in the local environment of a specific chest wall resection but also in its relation to overall function. An understanding of chest wall kinematics might help define the loss of function after resection and the effects of various chest wall substitutes. Therefore, this article is not an exhaustive anatomic description but a focused summary and discussion.

  20. The Structure of Plant Cell Walls

    PubMed Central

    Burke, David; Kaufman, Peter; McNeil, Michael; Albersheim, Peter

    1974-01-01

    The primary cell walls of six suspension-cultured monocots and of a single suspension-cultured gymnosperm have been investigated with the following results: (a) the compositions of all six monocot cell walls are remarkably similar, despite the fact that the cell cultures were derived from diverse tissues; (b) the cell walls of suspension-cultured monocots differ substantially from those of suspension-cultured dicots and from the suspension-cultured gymnosperm; (c) an arabinoxylan is a major component (40% or more by weight) of monocot primary cell walls; (d) mixed β-1,3; β-1,4-glucans were found only in the cell wall preparations of rye grass endosperm cells, and not in the cell walls of any of the other five monocot cell cultures nor in the walls of suspension-cultured Douglas fir cells; (e) the monocot primary cell walls studied contain from 9 to 14% cellulose, 7 to 18% uronic acids, and 7 to 17% protein; (f) hydroxyproline accounts for less than 0.2% of the cell walls of monocots. Similar data on the soluble extracellular polysaccharides secreted by these cells are included. PMID:16658824

  1. Molecular regulation of plant cell wall extensibility

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.

    1998-01-01

    Gravity responses in plants often involve spatial and temporal changes in cell growth, which is regulated primarily by controlling the ability of the cell wall to extend. The wall is thought to be a cellulose-hemicellulose network embedded in a hydrated matrix of complex polysaccharides and a small amount of structural protein. The wall extends by a form of polymer creep, which is mediated by expansins, a novel group of wall-loosening proteins. Expansins were discovered during a molecular dissection of the "acid growth" behavior of cell walls. Expansin alters the rheology of plant walls in profound ways, yet its molecular mechanism of action is still uncertain. It lacks detectable hydrolytic activity against the major components of the wall, but it is able to disrupt noncovalent adhesion between wall polysaccharides. The discovery of a second family of expansins (beta-expansins) sheds light on the biological role of a major group of pollen allergens and implies that expansins have evolved for diverse developmental functions. Finally, the contribution of other processes to wall extensibility is briefly summarized.

  2. Great attractor really a great wall

    SciTech Connect

    Stebbins, A.; Turner, M.S.

    1988-11-01

    Some of the cosmological consequences are discussed of a late time phase transition which produces light domain walls. The observed peculiar velocity field of the Universe and the observed isotropy of the microwave background radiation severely constrain the wall surface density in such a scenario. The most interesting consequence of such a phase transition is the possibility that the local, coherent streaming motion reported by the Seven Samurai could be explained by the repulsive effect of a relic domain wall with the Hubble volume (the Great Wall).

  3. Fillability of Thin-Wall Steel Castings

    SciTech Connect

    Robert C. Voigt; Joseph Bertoletti; Andrew Kaley; Sandi Ricotta; Travis Sunday

    2002-07-30

    The use of steel components is being challenged by lighter nonferrous or cast iron components. The development of techniques for enhancing and ensuring the filability of thin-wall mold cavities is most critical for thinner wall cast steel production. The purpose of this research was to develop thin-wall casting techniques that can be used to reliably produce thin-wall castings from traditional gravity poured sand casting processes. The focus of the research was to enhance the filling behavior to prevent misrunds. Experiments were conducted to investigate the influence of various foundry variables on the filling of thin section steel castings. These variables include casting design, heat transfer, gating design, and metal fluidity. Wall thickness and pouring temperature have the greatest effect on casting fill. As wall thickness increases the volume to surface area of the casting increases, which increases the solidification time, allowing the metal to flow further in thicker sect ions. Pouring time is another significant variable affecting casting fill. Increases or decreases of 20% in the pouring time were found to have a significant effect on the filling of thin-wall production castings. Gating variables, including venting, pouring head height, and mold tilting also significantly affected thin-wall casting fill. Filters offer less turbulent, steadier flow, which is appropriate for thicker castings, but they do not enhance thin-wall casting fill.

  4. First wall for polarized fusion reactors

    DOEpatents

    Greenside, H.S.; Budny, R.V.; Post, D.E. Jr.

    1985-01-29

    A first-wall or first-wall coating for use in a fusion reactor having polarized fuel may be formed of a low-Z non-metallic material having slow spin relaxation, i.e., a depolarization rate greater than 1 sec/sup -1/. Materials having these properties include hydrogenated and deuterated amorphous semiconductors. A method for preventing the rapid depolarization of a polarized plasma in a fusion device may comprise the step of providing a first-wall or first-wall coating formed of a low-Z, non-metallic material having a depolarization rate greater than 1 sec/sup -1/.

  5. CT evaluation of thickened esophageal walls

    SciTech Connect

    Reinig, J.W.; Stanley, J.H.; Schabel, S.I.

    1983-05-01

    A study of 200 consecutive chest computed tomographic (CT) examinations revealed thickened esophageal walls (over 3 mm) in 35%. While this is the earliest finding of carcinoma of the esophagus on CT, only half of the cases of thickened walls were due to esophageal carcinoma. Other mediastinal malignancies as well as benign inflammatory, vascular, and fibrotic conditions such as reflux and monilial esophagitis, esophageal varices, and postirradiation scarring were found to cause thickened esophageal walls. Distension with air and intravenous enhancement aid in the optimal evaluation of the esophagus by CT. The thickened esophageal wall is always abnormal, but it is nonspecific, seen in both malignant and nonmalignant conditions.

  6. Large-eddy simulations with wall models

    NASA Technical Reports Server (NTRS)

    Cabot, W.

    1995-01-01

    The near-wall viscous and buffer regions of wall-bounded flows generally require a large expenditure of computational resources to be resolved adequately, even in large-eddy simulation (LES). Often as much as 50% of the grid points in a computational domain are devoted to these regions. The dense grids that this implies also generally require small time steps for numerical stability and/or accuracy. It is commonly assumed that the inner wall layers are near equilibrium, so that the standard logarithmic law can be applied as the boundary condition for the wall stress well away from the wall, for example, in the logarithmic region, obviating the need to expend large amounts of grid points and computational time in this region. This approach is commonly employed in LES of planetary boundary layers, and it has also been used for some simple engineering flows. In order to calculate accurately a wall-bounded flow with coarse wall resolution, one requires the wall stress as a boundary condition. The goal of this work is to determine the extent to which equilibrium and boundary layer assumptions are valid in the near-wall regions, to develop models for the inner layer based on such assumptions, and to test these modeling ideas in some relatively simple flows with different pressure gradients, such as channel flow and flow over a backward-facing step. Ultimately, models that perform adequately in these situations will be applied to more complex flow configurations, such as an airfoil.

  7. Domain walls in antiferromagnetically coupled multilayer films.

    PubMed

    Hellwig, Olav; Berger, Andreas; Fullerton, Eric E

    2003-11-07

    We report experimentally observed magnetic domain-wall structures in antiferromagnetically coupled multilayer films with perpendicular anisotropy. Our studies reveal a first-order phase transition from domain walls with no net moment to domain walls with ferromagnetic cores. The transition originates from the competition between dipolar and exchange energies, which we tune by means of layer thickness. Although observed in a synthetic antiferromagnetic system, such domain-wall structures may be expected to occur in A-type antiferromagnets with anisotropic exchange coupling.

  8. Scaling analysis on filtered near wall turbulence

    NASA Astrophysics Data System (ADS)

    Mohan, Prakash; Moser, Robert

    2016-11-01

    Large Eddy Simulations (LES) directly represent larger scale turbulent motions and model the effects of small scale motions. However in the near wall region the large dynamically important eddies scale in viscous wall units, which makes resolving them in a high Reynolds number LES very expensive. This motivates the use of wall-modeled LES, in which these near-wall eddies are modeled. To aid in the development of new wall models, we pursue an asymptotic analysis of the filtered Navier-Stokes equations, in the limit in which the horizontal filter scale is large compared to the thickness of the wall layer. It will be shown that in this limit the filtered velocities u and subgrid stresses τ in the near-wall layer are determined to zeroth order by filtered velocities at the boundary of the wall layer. Further the asymptotics suggest that there is a scaled universal velocity profile f and subgrid stress profile g in the near-wall region. The validity of this result will be tested and the profiles f and g will be evaluated through analysis of DNS data from channel flow at Reτ = 5200 .

  9. The formation and evolution of domain walls

    NASA Technical Reports Server (NTRS)

    Press, William H.; Ryden, Barbara S.; Spergel, David N.

    1991-01-01

    Domain walls are sheet-like defects produced when the low energy vacuum has isolated degenerate minima. The researchers' computer code follows the evolution of a scalar field, whose dynamics are determined by its Lagrangian density. The topology of the scalar field determines the evolution of the domain walls. This approach treats both wall dynamics and reconnection. The researchers investigated not only potentials that produce single domain walls, but also potentials that produce a network of walls and strings. These networks arise in axion models where the U(1) Peccei-Quinn symmetry is broken into Z sub N discrete symmetries. If N equals 1, the walls are bounded by strings and the network quickly disappears. For N greater than 1, the network of walls and strings behaved qualitatively just as the wall network shown in the figures given here. This both confirms the researchers' pessimistic view that domain walls cannot play an important role in the formation of large scale structure and implies that axion models with multiple minimum can be cosmologically disastrous.

  10. Corrections to the thin wall approximation in general relativity

    NASA Technical Reports Server (NTRS)

    Garfinkle, David; Gregory, Ruth

    1989-01-01

    The question is considered whether the thin wall formalism of Israel applies to the gravitating domain walls of a lambda phi(exp 4) theory. The coupled Einstein-scalar equations that describe the thick gravitating wall are expanded in powers of the thickness of the wall. The solutions of the zeroth order equations reproduce the results of the usual Israel thin wall approximation for domain walls. The solutions of the first order equations provide corrections to the expressions for the stress-energy of the wall and to the Israel thin wall equations. The modified thin wall equations are then used to treat the motion of spherical and planar domain walls.

  11. Electromagnetic approaches to wall characterization, wall mitigation, and antenna design for through-the-wall radar systems

    NASA Astrophysics Data System (ADS)

    Thajudeen, Christopher

    Through-the-wall imaging (TWI) is a topic of current interest due to its wide range of public safety, law enforcement, and defense applications. Among the various available technologies such as, acoustic, thermal, and optical imaging, which can be employed to sense and image targets of interest, electromagnetic (EM) imaging, in the microwave frequency bands, is the most widely utilized technology and has been at the forefront of research in recent years. The primary objectives for any Through-the-Wall Radar Imaging (TWRI) system are to obtain a layout of the building and/or inner rooms, detect if there are targets of interest including humans or weapons, determine if there are countermeasures being employed to further obscure the contents of a building or room of interest, and finally to classify the detected targets. Unlike conventional radar scenarios, the presence of walls, made of common construction materials such as brick, drywall, plywood, cinder block, and solid concrete, adversely affects the ability of any conventional imaging technique to properly image targets enclosed within building structures as the propagation through the wall can induce shadowing effects on targets of interest which may result in image degradation, errors in target localization, and even complete target masking. For many applications of TWR systems, the wall ringing signals are strong enough to mask the returns from targets not located a sufficient distance behind the wall, beyond the distance of the wall ringing, and thus without proper wall mitigation, target detection becomes extremely difficult. The results presented in this thesis focus on the development of wall parameter estimation, and intra-wall and wall-type characterization techniques for use in both the time and frequency domains as well as analysis of these techniques under various real world scenarios such as reduced system bandwidth scenarios, various wall backing scenarios, the case of inhomogeneous walls, presence

  12. Phase-averaged wall shear stress, wall pressure, and near-wall velocity field measurements in a whirling annular seal

    SciTech Connect

    Morrison, G.L.; Winslow, R.B.; Thames, H.D. III

    1996-07-01

    The flow field inside a 50 percent eccentric whirling annular seal operating at a Reynolds number of 24,000 and a Taylor number of 6600 has been measured using a three-dimensional laser-Doppler anemometer system. Flush mount pressure and wall shear stress probes have been used to measure the stresses (normal and shear) along the length of the stator. The rotor was mounted eccentrically on the shaft so that the rotor orbit was circular and rotated at the same speed as the shaft (a whirl ratio of 1.0). This paper presents mean pressure, mean wall shear stress magnitude, and mean wall shear stress direction distributions along the length of the seal. Phase-averaged wall pressure and wall shear stress are presented along with phase-averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall, where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure, and wall shear stress are very complex and do not follow simple bulk flow predictions.

  13. Analysis of dynamic diffuse wall based on two-dimensional twist wall

    NASA Astrophysics Data System (ADS)

    Fujii, T.; Kumosaki, K.; Inoue, M.

    1981-03-01

    The mechanism and the dynamic properties of the dynamic diffuse wall observed in Garnet bubbles have been analyzed based on two dimensional twist wall with a finite film thickness. The analysis reveals that during wall motion, 360 °-spin twist nucleates inside the wall and propagates along the film thickness. The wall distortion takes place where the 360 °-twist appears. Annihilation and/or accumulation of the 360 °-twist occurs at the film surface. The number of the 360 °-twists contained in a wall increases with increasing drive and in-plane fields, which leads to an increase of the apparent wall width obtained by domain walls observed by transmitted light (Faraday effect). Most of the experimental results may be well interpreted by the present analysis.

  14. 8. NORTHWEST WALL OF AR8, ALSO SHOWING THE SOUTHWEST WALL ...

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

    8. NORTHWEST WALL OF AR-8, ALSO SHOWING THE SOUTHWEST WALL AND THE CREW SHELTER AT FAR RIGHT. - Edwards Air Force Base, South Base, Rammed Earth Aircraft Dispersal Revetments, Western Shore of Rogers Dry Lake, Boron, Kern County, CA

  15. A wall interference assessment/correction system

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.

    1993-01-01

    A Wall Signature method originally developed by Hackett was selected to be adapted for the Ames 12-ft Wind Tunnel Wall Interference Assessment/Correction (WIAC) System in the project. This method uses limited measurements of the static pressure at the wall, in conjunction with the solid wall boundary condition, to determine the strength and distribution of singularities representing the test article. The singularities are used in turn for estimating wall interference at the model location. The lifting interference will be treated separately by representing in a horseshoe vortex system for the model's lifting effects. The development and implementation of a working prototype will be completed, delivered, and documented with a software manual. The WIAC code will be validated by conducting numerically simulated experiments rather than actual wind tunnel experiments. The simulations will be used to generate both free-air and confined wind-tunnel flow fields for each of the test articles over a range of test configurations. Specifically, the pressure signature at the test section wall will be computed for the tunnel case to provide the simulated 'measured' data. These data will serve as the input for the WIAC method - Wall Signature method. The performance of the WIAC method then may be evaluated by comparing the corrected parameters with those for the free-air simulation. The following two additional tasks are included in the supplement No. 1 to the basic Grant. On-line wall interference calculation: The developed wall signature method (modified Hackett's method) for Ames 12-ft Tunnel will be the pre-computed coefficients which facilitate the on-line calculation of wall interference; and support system effects estimation: The effects on the wall pressure measurements due to the presence of the model support systems will be evaluated.

  16. External Insulation of Masonry Walls and Wood Framed Walls

    SciTech Connect

    Baker, P.

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1” to 1 ½”), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  17. External Insulation of Masonry Walls and Wood Framed Walls

    SciTech Connect

    Baker, P.

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1" to 1 1/2"), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  18. Indirect localization of a magnetic domain wall mediated by quasi walls

    PubMed Central

    Lacour, D.; Montaigne, F.; Rougemaille, N.; Belkhou, R.; Raabe, J.; Hehn, M.

    2015-01-01

    The manipulation of magnetic domain walls in thin films and nanostructures opens new opportunities for fundamental and applied research. But controlling reliably the position of a moving domain wall still remains challenging. So far, most of the studies aimed at understanding the physics of pinning and depinning processes in the magnetic layer in which the wall moves (active layer). In these studies, the role of other magnetic layers in the stack has been often ignored. Here, we report an indirect localization process of 180° domain walls that occurs in magnetic tunnel junctions, commonly used in spintronics. Combining Scanning Transmission X-Ray Microscopy and micromagnetic simulations, magnetic configurations in both layers are resolved. When nucleating a 180° domain wall in the active layer, a quasi wall is created in the reference layer, atop the wall. The wall and its quasi wall must then be moved or positioned together, as a unique object. As a mutual effect, a localized change of the magnetic properties in the reference layer induces a localized quasi wall in the active layer. The two types of quasi walls are shown to be responsible for an indirect localization process of the 180° domain wall in the active layer. PMID:26011004

  19. 7. NORTH WALL AND NORTHWEST WALL OF AR8, ALSO SHOWING ...

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

    7. NORTH WALL AND NORTHWEST WALL OF AR-8, ALSO SHOWING THE EAST END OF THE SOUTH WALL IN THE DISTANCE. VIEW TO SOUTH. - Edwards Air Force Base, South Base, Rammed Earth Aircraft Dispersal Revetments, Western Shore of Rogers Dry Lake, Boron, Kern County, CA

  20. Indirect localization of a magnetic domain wall mediated by quasi walls.

    PubMed

    Lacour, D; Montaigne, F; Rougemaille, N; Belkhou, R; Raabe, J; Hehn, M

    2015-05-26

    The manipulation of magnetic domain walls in thin films and nanostructures opens new opportunities for fundamental and applied research. But controlling reliably the position of a moving domain wall still remains challenging. So far, most of the studies aimed at understanding the physics of pinning and depinning processes in the magnetic layer in which the wall moves (active layer). In these studies, the role of other magnetic layers in the stack has been often ignored. Here, we report an indirect localization process of 180° domain walls that occurs in magnetic tunnel junctions, commonly used in spintronics. Combining Scanning Transmission X-Ray Microscopy and micromagnetic simulations, magnetic configurations in both layers are resolved. When nucleating a 180° domain wall in the active layer, a quasi wall is created in the reference layer, atop the wall. The wall and its quasi wall must then be moved or positioned together, as a unique object. As a mutual effect, a localized change of the magnetic properties in the reference layer induces a localized quasi wall in the active layer. The two types of quasi walls are shown to be responsible for an indirect localization process of the 180° domain wall in the active layer.

  1. Safranine fluorescent staining of wood cell walls.

    PubMed

    Bond, J; Donaldson, L; Hill, S; Hitchcock, K

    2008-06-01

    Safranine is an azo dye commonly used for plant microscopy, especially as a stain for lignified tissues such as xylem. Safranine fluorescently labels the wood cell wall, producing green/yellow fluorescence in the secondary cell wall and red/orange fluorescence in the middle lamella (ML) region. We examined the fluorescence behavior of safranine under blue light excitation using a variety of wood- and fiber-based samples of known composition to interpret the observed color differentiation of different cell wall types. We also examined the basis for the differences in fluorescence emission using spectral confocal microscopy to examine lignin-rich and cellulose-rich cell walls including reaction wood and decayed wood compared to normal wood. Our results indicate that lignin-rich cell walls, such as the ML of tracheids, the secondary wall of compression wood tracheids, and wood decayed by brown rot, tend to fluoresce red or orange, while cellulose-rich cell walls such as resin canals, wood decayed by white rot, cotton fibers and the G-layer of tension wood fibers, tend to fluoresce green/yellow. This variation in fluorescence emission seems to be due to factors including an emission shift toward red wavelengths combined with dye quenching at shorter wavelengths in regions with high lignin content. Safranine fluorescence provides a useful way to differentiate lignin-rich and cellulose-rich cell walls without counterstaining as required for bright field microscopy.

  2. Differential scanning calorimetry of plant cell walls

    SciTech Connect

    Lin, Liangshiou; Varner, J.E. ); Yuen, H.K. )

    1991-03-15

    High-sensitivity differential scanning calorimetry has been used to study the phase transition of cell wall preparations of the elongating and mature regions of soybean hypocotyls and of celery epidermis and collenchyma strands. A step-like transition believed to be glass transition was observed in walls isolated from the elongating region of soybean hypocotyls at 52.9C. Addition of 1 mM CaCl{sub 2} to the cell wall preparation increased the transition temperature to 60.8C and greatly reduced the transition magnitude. In walls from the mature region, the transition was small and occurred at a higher temperature (60.1C). Addition of calcium to the mature region cell wall had little effect on the transition. Based on the known interactions between calcium and pectin, the authors propose that calcium affects the glass transition by binding to the polygalacturonate backbone of wall pectin, resulting in a more rigid wall with a smaller transition at a higher temperature. The mature region either has more calcium in the wall or has more methyl-esterified pectin, making it less responsive to added calcium.

  3. Biosynthesis: Imaging cell-wall biosynthesis live

    NASA Astrophysics Data System (ADS)

    Bugg, Timothy D. H.

    2013-01-01

    The biosynthesis of peptidoglycan is an important step in bacterial cell division and cell-wall maturation. Now it has been shown that fluorescent D-amino acids can be used to label the peptidoglycan cell wall of living bacteria, providing a new tool to study this important process.

  4. Risk Assessment of Energy-Efficient Walls

    SciTech Connect

    Pallin, Simon B.; Hun, Diana E.; Jackson, Roderick K.; Kehrer, Manfred

    2014-12-01

    This multi-year project aims to provide the residential construction industry with energy-efficient wall designs that are moisture durable. The present work focused on the initial step of this project, which is to develop a moisture durability protocol that identifies energy efficient wall designs that have a low probability of experiencing moisture problems.

  5. Life Behind the Wall: Palestinian Students Online

    ERIC Educational Resources Information Center

    Hart, Doug

    2007-01-01

    In this article, the author discusses an online youth magazine that his Palestinian students developed. In April of 2006, they launched the inaugural edition of their teen e-zine, "Behind the Wall." With the help of his brother-in-law, students, along with a computer programmer, the "Behind the Wall" website was constructed.…

  6. [The cell wall of Coelastrum (Chlorophycees)].

    PubMed

    Reymond, O

    1975-01-01

    The cell wall of Coelastrum is usually composed of three layers. The outermost layer was studied most extensively. It consists of erect tubules which often bear long bristles whose function may be to stabilize the algae in its enviroment. The cell wall can modify its morphology according to the enviroment.

  7. Revisiting the Ladder on a Wall Problem

    ERIC Educational Resources Information Center

    Salu, Yehuda

    2011-01-01

    The problem of a ladder leaning on a wall has been a staple of introductory physics for years. It is discussed in numerous physics textbooks and in journals. Now, it even has an Internet presence. Postings from students seek help for "ladder on a wall" problems. A quick review of those postings would show that they all deal with frictionless…

  8. Turbulence measurements in curved wall jets

    NASA Astrophysics Data System (ADS)

    Rodman, L. C.; Wood, N. J.; Roberts, L.

    1987-01-01

    Accurate turbulence measurements taken in wall jet flows are difficult to obtain, due to high intensity turbulence and problems in achieving two-dimensionality. The problem is compounded when streamwise curvature of the flow is introduced, since the jet entrainment and turbulence levels are greatly increased over the equivalent planar values. In this experiment, two-dimensional plane and curved wall jet flows are simulated by having a jet blow axially over a cylinder. In the plane case the cylinder has constant transverse radius, and in the curved cases the cylinder has a varying transverse radius. Although the wall jet in these cases is axisymmetric, adequate 'two-dimensional' flow can be obtained as long as the ratio of the jet width to the cylinder radius is small. The annular wall jet has several advantages over wall jets issuing from finite rectangular slots. Since the slot has no ends, three-dimensional effects caused by the finite length of the slot and side wall interference are eliminated. Also, the transverse curvature of the wall allows close optical access to the surface using a Laser Doppler Velocimetry (LDV) system. Hot wire measurements and some LDV measurements are presented for plane and curved wall jet flows. An integral analysis is used to assess the effects of transverse curvature on the turbulent shear stress. The analysis and the data show that the effects of transverse curvature on both the mean flow and the shear stress are small enough for two-dimensional flow to be approximately satisfactorily.

  9. Ballistic Limit Equation for Single Wall Titanium

    NASA Technical Reports Server (NTRS)

    Ratliff, J. M.; Christiansen, Eric L.; Bryant, C.

    2009-01-01

    Hypervelocity impact tests and hydrocode simulations were used to determine the ballistic limit equation (BLE) for perforation of a titanium wall, as a function of wall thickness. Two titanium alloys were considered, and separate BLEs were derived for each. Tested wall thicknesses ranged from 0.5mm to 2.0mm. The single-wall damage equation of Cour-Palais [ref. 1] was used to analyze the Ti wall's shielding effectiveness. It was concluded that the Cour-Palais single-wall equation produced a non-conservative prediction of the ballistic limit for the Ti shield. The inaccurate prediction was not a particularly surprising result; the Cour-Palais single-wall BLE contains shield material properties as parameters, but it was formulated only from tests of different aluminum alloys. Single-wall Ti shield tests were run (thicknesses of 2.0 mm, 1.5 mm, 1.0 mm, and 0.5 mm) on Ti 15-3-3-3 material custom cut from rod stock. Hypervelocity impact (HVI) tests were used to establish the failure threshold empirically, using the additional constraint that the damage scales with impact energy, as was indicated by hydrocode simulations. The criterion for shield failure was defined as no detached spall from the shield back surface during HVI. Based on the test results, which confirmed an approximately energy-dependent shield effectiveness, the Cour-Palais equation was modified.

  10. Mechanics of the Toxoplasma gondii oocyst wall

    USDA-ARS?s Scientific Manuscript database

    The ability of microorganisms to survive under extreme conditions is closely related to the physicochemical properties of their wall. In the ubiquitous protozoan parasite Toxoplasma gondii, the oocyst stage possesses a bilayered wall that protects the dormant but potentially infective parasites from...

  11. 14 CFR 121.245 - Fire walls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Fire walls. 121.245 Section 121.245..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.245 Fire walls. Each engine, auxiliary power unit, fuel-burning heater, or other item of combustion equipment that is intended for...

  12. 14 CFR 121.245 - Fire walls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Fire walls. 121.245 Section 121.245 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.245 Fire walls. Each...

  13. 14 CFR 121.245 - Fire walls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Fire walls. 121.245 Section 121.245 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.245 Fire walls. Each...

  14. 14 CFR 121.245 - Fire walls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Fire walls. 121.245 Section 121.245 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.245 Fire walls. Each...

  15. Air pressures in wood frame walls

    Treesearch

    Anton. TenWolde; Charles G. Carll; Vyto. Malinauskas

    1998-01-01

    Wind pressures can play an important role in the wetting of exterior walls (driving rain). In response, the rain screen concept, including compartmentalization and air spaces, has been developed to provide pressure equalization and limit water entry into the wall. However, conventional construction such as wood lap siding has not been evaluated as to its ability to...

  16. Do plant cell walls have a code?

    PubMed

    Tavares, Eveline Q P; Buckeridge, Marcos S

    2015-12-01

    A code is a set of rules that establish correspondence between two worlds, signs (consisting of encrypted information) and meaning (of the decrypted message). A third element, the adaptor, connects both worlds, assigning meaning to a code. We propose that a Glycomic Code exists in plant cell walls where signs are represented by monosaccharides and phenylpropanoids and meaning is cell wall architecture with its highly complex association of polymers. Cell wall biosynthetic mechanisms, structure, architecture and properties are addressed according to Code Biology perspective, focusing on how they oppose to cell wall deconstruction. Cell wall hydrolysis is mainly focused as a mechanism of decryption of the Glycomic Code. Evidence for encoded information in cell wall polymers fine structure is highlighted and the implications of the existence of the Glycomic Code are discussed. Aspects related to fine structure are responsible for polysaccharide packing and polymer-polymer interactions, affecting the final cell wall architecture. The question whether polymers assembly within a wall display similar properties as other biological macromolecules (i.e. proteins, DNA, histones) is addressed, i.e. do they display a code?

  17. Cartilage in the walls of odontogenic keratocyst.

    PubMed

    Vicente-Barrero, Mario; Báez-Marrero, Oswaldo; Alfonso-Martín, Juan Luis; Knezevic, Milan; Báez-Acosta, Beatriz; Camacho-García, Maria del Carmen; Montenegro-Dámaso, Társila

    2004-01-01

    There are seven published cases in world literature on cartilage in the walls of odontogenic keratocysts. Herein is presented one further case with keratin inclusions in the cystic wall, which also bears a cartilaginous component. X-rays, clinical images and pathohistological images are included.

  18. Artificial Climbing Wall Design and Use.

    ERIC Educational Resources Information Center

    Cinnamon, Jerry

    Climbing walls can be designed to satisfy the needs of both untrained and experienced climbers offering these people a place to learn their craft as well as a place for them to keep their skills honed during off seasons. Users of the artificial wall can be classified into special groups, such as "Youth at Risk," who are engaged in…

  19. Revisiting the Ladder on a Wall Problem

    ERIC Educational Resources Information Center

    Salu, Yehuda

    2011-01-01

    The problem of a ladder leaning on a wall has been a staple of introductory physics for years. It is discussed in numerous physics textbooks and in journals. Now, it even has an Internet presence. Postings from students seek help for "ladder on a wall" problems. A quick review of those postings would show that they all deal with frictionless…

  20. Near-wall serpentine cooled turbine airfoil

    SciTech Connect

    Lee, Ching-Pang

    2014-10-28

    A serpentine coolant flow path is formed by inner walls in a cavity between pressure and suction side walls of a turbine airfoil, the cavity partitioned by one or more transverse partitions into a plurality of continuous serpentine cooling flow streams each having a respective coolant inlet.

  1. Differential scanning calorimetry of plant cell walls.

    PubMed Central

    Lin, L S; Yuen, H K; Varner, J E

    1991-01-01

    High-sensitivity differential scanning calorimetry has been used to study the phase transition of cell wall preparations of the elongating and mature regions of soybean hypocotyls and of celery epidermis and collenchyma strands. A step-like transition believed to be glass transition was observed in walls isolated from the elongating region of soybean hypocotyls at 52.9 degrees C. Addition of 1 mM CaCl2 to the cell wall preparation increased the transition temperature to 60.8 degrees C and greatly reduced the transition magnitude. In walls from the mature region, the transition was small and occurred at a higher temperature (60.1 degrees C). Addition of calcium to the mature region cell wall had little effect on the transition. Based on the known interactions between calcium and pectin, we propose that calcium affects the glass transition by binding to the polygalacturonate backbone of wall pectin, resulting in a more rigid wall with a smaller transition at a higher temperature. The mature region either has more calcium in the wall or has more methyl-esterified pectin, making it less responsive to added calcium. PMID:11607163

  2. Artificial Climbing Wall Design and Use.

    ERIC Educational Resources Information Center

    Cinnamon, Jerry

    Climbing walls can be designed to satisfy the needs of both untrained and experienced climbers offering these people a place to learn their craft as well as a place for them to keep their skills honed during off seasons. Users of the artificial wall can be classified into special groups, such as "Youth at Risk," who are engaged in…

  3. Steel shear walls, behavior, modeling and design

    SciTech Connect

    Astaneh-Asl, Abolhassan

    2008-07-08

    In recent years steel shear walls have become one of the more efficient lateral load resisting systems in tall buildings. The basic steel shear wall system consists of a steel plate welded to boundary steel columns and boundary steel beams. In some cases the boundary columns have been concrete-filled steel tubes. Seismic behavior of steel shear wall systems during actual earthquakes and based on laboratory cyclic tests indicates that the systems are quite ductile and can be designed in an economical way to have sufficient stiffness, strength, ductility and energy dissipation capacity to resist seismic effects of strong earthquakes. This paper, after summarizing the past research, presents the results of two tests of an innovative steel shear wall system where the boundary elements are concrete-filled tubes. Then, a review of currently available analytical models of steel shear walls is provided with a discussion of capabilities and limitations of each model. We have observed that the tension only 'strip model', forming the basis of the current AISC seismic design provisions for steel shear walls, is not capable of predicting the behavior of steel shear walls with length-to-thickness ratio less than about 600 which is the range most common in buildings. The main reasons for such shortcomings of the AISC seismic design provisions for steel shear walls is that it ignores the compression field in the shear walls, which can be significant in typical shear walls. The AISC method also is not capable of incorporating stresses in the shear wall due to overturning moments. A more rational seismic design procedure for design of shear walls proposed in 2000 by the author is summarized in the paper. The design method, based on procedures used for design of steel plate girders, takes into account both tension and compression stress fields and is applicable to all values of length-to-thickness ratios of steel shear walls. The method is also capable of including the effect of

  4. Cell Wall Composition of Hyphomicrobium Species1

    PubMed Central

    Jones, H. E.; Hirsch, Peter

    1968-01-01

    Chemical analysis of cell walls obtained from Hyphomicrobium B-522 and from a morphologically and nutritionally distinct organism, Hyphomicrobium neptunium (ATCC 15444), showed that the organisms have a similar cell wall composition, which is typical of gram-negative bacteria. The walls of both strains contained many amino acids, including the characteristic mucopeptide components diaminopimelic acid and muramic acid. Isolation of the mucopeptide by use of sodium dodecyl sulfate was successful only with cell walls of H. neptunium, thus revealing a difference between the walls of the two strains. The mucopeptide preparation contained glucosamine, muramic acid, alanine, glutamic acid, diaminopimelic acid, and glycine in molar ratios of 1.05:1.21:1.84:1.0:1.04:0.31, respectively. The concentration of glycine was sufficiently high to suggest that it is a mucopeptide component rather than an impurity. PMID:5685989

  5. Aging near the wall in colloidal glasses

    NASA Astrophysics Data System (ADS)

    Cao, Cong; Huang, Xinru; Weeks, Eric

    In a colloidal glass system, particles move slower as sample ages. In addition, their motions may be affected by their local structure, and this structure will be different near a wall. We examine how the aging process near a wall differs from that in the bulk of the sample. In particular, we use a confocal microscope to observe 3D motion in a bidisperse colloidal glass sample. We find that flat walls induce the particles to organize into layers. The aging process behaves differently near the boundary, especially within the first three layers. Particle motion near the wall is noticeably slower but also changes less dramatically with age. We compare and contrast aging seen in samples with flat and rough walls.

  6. The interaction of transverse domain walls.

    PubMed

    Krüger, Benjamin

    2012-01-18

    The interaction between transverse domain walls is calculated analytically using a multipole expansion up to third order. Starting from an analytical expression for the magnetization in the wall, the monopole, dipole, and quadrupole moments are derived and their impact on the interaction is investigated using the surface and volume charges. The surface charges are important for the dipole moment while the volume charges constitute the monopole and quadrupole moments. For domain walls that are situated in different wires it is found that there is a strong deviation from the interaction of two monopoles. This deviation is caused by the interaction of the monopole of the wall in the first wire with the dipole of the wall in the second wire and vice versa. The dipole-dipole and the quadrupole-monopole interactions are found to be also of considerable size and non-negligible. A comparison with micromagnetic simulations shows a good agreement.

  7. Anther Wall Formation in Solanaceae Species

    PubMed Central

    CARRIZO GARCÍA, CAROLINA

    2002-01-01

    Anther wall formation was studied in 32 species belonging to 27 genera of Solanaceae. Dicotyledonous and basic types of wall formation were observed, as well as several deviations due to subsequent periclinal divisions in the layers formed (middle layers and sometimes the endothecium). One type of wall formation was observed in each species. Some genera are uniform in their type of wall formation, while others are heterogeneous; a similar situation was observed at the tribal level. Summarizing all reported information on anther wall formation in the Solanaceae, 64 % of species show the basic type, while the remaining 36 % show the dicotyledonous type. Thus, neither type predominates, and no single type characterizes genera, tribes or the entire family. PMID:12451025

  8. Through-the-wall polarimetric imaging

    NASA Astrophysics Data System (ADS)

    Ahmad, Fauzia; Amin, Moeness G.

    2008-04-01

    Through-the-Wall Imaging is emerging as an affordable sensor technology supporting a variety of applications, such as surveillance and reconnaissance, emergency rescue, and firefighting. Motivated by the desire to understand the underlying phenomenology and performance bounds associated with imaging targets behind walls, several through-the-wall imaging experiments were conducted at the Center for Advanced Communications (CAC), Villanova University. These experiments aimed at supporting resolution, polarization, and localization of indoor targets and objects behind walls, and provided valuable dual-polarized synthetic aperture data measurements of indoor scenes of different complexity and population. In this paper, we present full-polarization imaging results, for a setting of calibrated reflectors behind a typical exterior grade wall. These imaging results provide polarimetric scene characterization and are shown to be in good agreement with the ground truth.

  9. Accelerating forward genetics for cell wall deconstruction

    PubMed Central

    Vidaurre, Danielle; Bonetta, Dario

    2012-01-01

    The elucidation of the genes involved in cell wall synthesis and assembly remains one of the biggest challenges of cell wall biology. Although traditional genetic approaches, using simple yet elegant screens, have identified components of the cell wall, many unknowns remain. Exhausting the genetic toolbox by performing sensitized screens, adopting chemical genetics or combining these with improved cell wall imaging, hold the promise of new gene discovery and function. With the recent introduction of next-generation sequencing technologies, it is now possible to quickly and efficiently map and clone genes of interest in record time. The combination of a classical genetics approach and cutting edge technology will propel cell wall biology in plants forward into the future. PMID:22685448

  10. Automotion of domain walls for spintronic interconnects

    SciTech Connect

    Nikonov, Dmitri E.; Manipatruni, Sasikanth; Young, Ian A.

    2014-06-07

    We simulate “automotion,” the transport of a magnetic domain wall under the influence of demagnetization and magnetic anisotropy, in nanoscale spintronic interconnects. In contrast to spin transfer driven magnetic domain wall motion, the proposed interconnects operate without longitudinal charge current transfer, with only a transient current pulse at domain wall creation and have favorable scaling down to the 20 nm dimension. Cases of both in-plane and out-of-plane magnetization are considered. Analytical dependence of the velocity of domain walls on the angle of magnetization are compared with full micromagnetic simulations. Deceleration, attenuation and disappearance, and reflection of domain walls are demonstrated through simulation. Dependences of the magnetization angle on the current pulse parameters are studied. The energy and delay analysis suggests that automotion is an attractive option for spintronic logic interconnects.

  11. 2003 Plant Cell Walls Gordon Conference

    SciTech Connect

    Daniel J. Cosgrove

    2004-09-21

    This conference will address recent progress in many aspects of cell wall biology. Molecular, genetic, and genomic approaches are yielding major advances in our understanding of the composition, synthesis, and architecture of plant cell walls and their dynamics during growth, and are identifying the genes that encode the machinery needed to make their biogenesis possible. This meeting will bring together international scientists from academia, industry and government labs to share the latest breakthroughs and perspectives on polysaccharide biosynthesis, wood formation, wall modification, expansion and interaction with other organisms, and genomic & evolutionary analyses of wall-related genes, as well as to discuss recent ''nanotechnological'' advances that take wall analysis to the level of a single cell.

  12. Metal stud wall systems -- Thermal disaster, or modern wall systems with highly efficient thermal insulation?

    SciTech Connect

    Kosny, J.; Christian, J.E.; Desjarlais, A.O.

    1997-11-01

    Because steel has higher thermal conductivity than wood and intense heat transfer occurs through the metal wall components, thermal performances of a metal stud wall are significantly lower than for similar wood stud walls. A reduction of the in-cavity R-value caused by the wood studs is about 10% in wood stud walls. That is why metal stud walls are believed to be considerably less thermally effective than similar made of wood. However, properly designed metal stud walls can be as thermally effective as wood stud walls. Relatively high R-values may be achieved by installing insulating sheathing, which is widely used as a remedy for a weak thermal performance of metal stud walls. A series of the promising metal stud wall configurations is analyzed using results of finite difference computer modeling and guarded hotbox tests. Some of these walls were designed and tested in the ORNL Building Technology Center, some were tested in other laboratories, and some walls were developed and forgotten long time ago. Also, a novel concept of combined foam-metal studs is considered. The main aim of the present paper is to prove that it is possible to build metal stud walls which perform as well as wood stud walls. The key lies in designing; metal stud wall systems have to be treated in a special way with particular consideration to the high thermal conduction of metal components. In the discussed collection of the efficient metal stud wall configurations, reductions of the in-cavity R-value caused by metal studs are between 10 and 20%.

  13. Sunspot Light Walls Suppressed by Nearby Brightenings

    NASA Astrophysics Data System (ADS)

    Yang, Shuhong; Zhang, Jun; Erdélyi, Robertus; Hou, Yijun; Li, Xiaohong; Yan, Limei

    2017-07-01

    Light walls, as ensembles of oscillating bright structures rooted in sunspot light bridges, have not been well studied, although they are important for understanding sunspot properties. Using the Interface Region Imaging Spectrograph and Solar Dynamics Observatory observations, here we study the evolution of two oscillating light walls each within its own active region (AR). The emission of each light wall decays greatly after the appearance of adjacent brightenings. For the first light wall, rooted within AR 12565, the average height, amplitude, and oscillation period significantly decrease from 3.5 Mm, 1.7 Mm, and 8.5 minutes to 1.6 Mm, 0.4 Mm, and 3.0 minutes, respectively. For the second light wall, rooted within AR 12597, the mean height, amplitude, and oscillation period of the light wall decrease from 2.1 Mm, 0.5 Mm, and 3.0 minutes to 1.5 Mm, 0.2 Mm, and 2.1 minutes, respectively. Particularly, a part of the second light wall even becomes invisible after the influence of a nearby brightening. These results reveal that the light walls are suppressed by nearby brightenings. Considering the complex magnetic topology in light bridges, we conjecture that the fading of light walls may be caused by a drop in the magnetic pressure, where the flux is canceled by magnetic reconnection at the site of the nearby brightening. Another hypothesis is that the wall fading is due to the suppression of driver source (p-mode oscillation), resulting from the nearby avalanche of downward particles along reconnected brightening loops.

  14. Modifying crops to increase cell wall digestibility.

    PubMed

    Jung, Hans-Joachim G; Samac, Deborah A; Sarath, Gautam

    2012-04-01

    Improving digestibility of roughage cell walls will improve ruminant animal performance and reduce loss of nutrients to the environment. The main digestibility impediment for dicotyledonous plants is highly lignified secondary cell walls, notably in stem secondary xylem, which become almost non-digestible. Digestibility of grasses is slowed severely by lignification of most tissues, but these cell walls remain largely digestible. Cell wall lignification creates an access barrier to potentially digestible wall material by rumen bacteria if cells have not been physically ruptured. Traditional breeding has focused on increasing total dry matter digestibility rather than cell wall digestibility, which has resulted in minimal reductions in cell wall lignification. Brown midrib mutants in some annual grasses exhibit small reductions in lignin concentration and improved cell wall digestibility. Similarly, transgenic approaches down-regulating genes in monolignol synthesis have produced plants with reduced lignin content and improved cell wall digestibility. While major reductions in lignin concentration have been associated with poor plant fitness, smaller reductions in lignin provided measurable improvements in digestibility without significantly impacting agronomic fitness. Additional targets for genetic modification to enhance digestibility and improve roughages for use as biofuel feedstocks are discussed; including manipulating cell wall polysaccharide composition, novel lignin structures, reduced lignin/polysaccharide cross-linking, smaller lignin polymers, enhanced development of non-lignified tissues, and targeting specific cell types. Greater tissue specificity of transgene expression will be needed to maximize benefits while avoiding negative impacts on plant fitness.cauliflower mosiac virus (CaMV) 35S promoter. Published by Elsevier Ireland Ltd.

  15. A wall interference assessment/correction system

    NASA Technical Reports Server (NTRS)

    Lo, C. F.

    1994-01-01

    A Wall Signature method originally developed by Hackett has been selected to be adapted for the Ames 12-ft Wind Tunnel WIAC system in the project. This method uses limited measurements of the static pressure at the wall, in conjunction with the solid wall boundary condition, to determine the strength and distribution of singularities representing the test article. The singularities are used in turn for estimating wall interference at the model location. The development and implementation of a working prototype will be completed, delivered and documented with a software manual. The WIAC code will be validated by conducting numerically simulated experiments rather than actual wind tunnel experiments. The simulations will be used to generate both free-air and confined wind-tunnel flow fields for each of the test articles over a range of test configurations. Specifically, the pressure signature at the test section wall will be computed for the tunnel case to provide the simulated 'measured' data. These data will serve as the input for the WIAC method--Wall Signature method. The performance of the WIAC method then may be evaluated by comparing the corrected parameters with those for the free-air simulation. The following two additional tasks are included: (1) On-line wall interference calculation: The developed wall signature method (modified Hackett's method) for Ames 12-ft Tunnel will be the pre-computed coefficients which facilitate the on-line calculation of wall interference, and (2) Support system effects estimation: The effects on the wall pressure measurements due to the presence of the model support systems will be evaluated.

  16. Rijke tube with flexible walls

    NASA Astrophysics Data System (ADS)

    Mandre, Shreyas; Nguyen, Bao-Nhat; Li, Marvin

    2011-11-01

    Sound is excited spontaneously in a Rijke tube because the small temperature perturbations in an acoustic field interact with heat transfer from a heat source in the tube. The air particles near the heat source undergo a thermodynamic cyle converting heat to mechanical energy, which is heard as the sound emanating from the Rijke tube. This principle of energy conversion is used in thermoacoustic engines, and the main objective of this study is to improve their performance. The acoustic oscillations in the Rijke tube regulate the thermodynamic cycle, just as in conventional engines the cycle is controlled by the motion of a piston and the action of inlet and exit valves. The acoustic regulation in the Rijke tube, however, does not allow arbitrary control of the cycle in thermodynamic phase space. In this presentation, we introduce a new way of overcoming this limitation, one by using Rijke tubes with flexible walls. We will discuss how this modification allows for more general thermodynamic cycles to be executed by the air particles in the tube. This possibility, when used in thermoacoustic engines, opens a channel for further improving the engine performance.

  17. Wall crossing, quivers and crystals

    NASA Astrophysics Data System (ADS)

    Aganagic, Mina; Schaeffer, Kevin

    2012-10-01

    We study the spectrum of BPS D-branes on a Calabi-Yau manifold using the 0 + 1 dimensional quiver gauge theory that describes the dynamics of the branes at low energies. We argue that Seiberg dualities of the quiver correspond to crossing the "walls of the second kind" of Kontsevich and Soibelman. There is a large class of examples where the BPS degeneracies of quivers corresponding to one D6 brane bound to arbitrary numbers of D4, D2 and D0 branes are counted by melting crystal configurations. The shape of the crystal is determined by the Calabi-Yau geometry and the background B-field, and its microscopic structure by the quiver Q. We prove that the BPS degeneracies computed from Q and Q' are related by the Kontsevich-Soibelman formula. We also show that, in the limit of infinite B-field, the combinatorics of crystals becomes that of the topological vertex, thus re-deriving the Gromov-Witten/Donaldson-Thomas correspondence.

  18. Wall street comes to Washington.

    PubMed

    2004-08-01

    While health care cost trends likely will continue slowing through the end of 2004, the longer-term outlook for a sustained slowdown in underlying costs and private health insurance premiums largely depends on the strength of the economy, according to market and health policy experts at the Center for Studying Health System Change's (HSC) ninth annual Wall Street roundtable. Even as cost growth slows, insurers are practicing pricing discipline to keep premium trends ahead of cost trends to maintain profitability. Employers will continue to shift costs to workers through higher deductibles, copayments and coinsurance, but an improving economy could temper this trend as labor markets tighten. Employers remain skeptical of new health insurance products, including tiered-provider networks and consumer-driven health plans. Although growth in hospital use has slowed, the industry remains in the throes of a building boom. Increased payments to managed care plans could reinvigorate private plan participation in Medicare, but concerns about the federal budget deficit could prompt Congress to roll back rate increases.

  19. Final Report for "Stabilization of resistive wall modes using moving metal walls"

    SciTech Connect

    Forest, Cary B.

    2014-02-05

    The UW experiment used a linear pinch experiment to study the stabilization of MHD by moving metal walls. The methodology of the experiment had three steps. (1) Identify and understand the no-wall MHD instability limits and character, (2) identify and understand the thin-wall MHD instabilities (re- sistive wall mode), and then (3) add the spinning wall and understand its impact on stability properties. During the duration of the grant we accomplished all 3 of these goals, discovered new physics, and completed the experiment as proposed.

  20. Comparison of airfoil results from an adaptive wall test section and a porous wall test section

    NASA Technical Reports Server (NTRS)

    Mineck, Raymond E.

    1989-01-01

    Two wind tunnel investigations were conducted to assess two different wall interference alleviation/correction techniques: adaptive test section walls and classical analytical corrections. The same airfoil model has been tested in the adaptive wall test section of the NASA-Langley 0.3 m Transonic Cryogenic Tunnel (TCT) and in the National Aeronautical Establishment (NAE) High Reynolds Number 2-D facility. The model has a 9 in. chord and a CAST 10-2/DOA 2 airfoil section. The 0.3 m TCT adaptive wall test section has four solid walls with flexible top and bottom walls. The NAE test section has porous top and bottom walls and solid side walls. The aerodynamic results corrected for top and bottom wall interference at Mach numbers from 0.3 to 0.8 at a Reynolds number of 10 by 1,000,000. Movement of the adaptive walls was used to alleviate the top and bottom wall interference in the test results from the NASA tunnel.

  1. Wall shear stress measurement in blade end-wall corner region

    NASA Technical Reports Server (NTRS)

    Bhargava, R.; Raj, R.; Boldman, D. R.

    1987-01-01

    The magnitude and the direction of wall shear stress and surface pressure in the blade end-wall corner region were investigated. The measurements were obtained on a specially designed Preston tube, the tip of which could be concentrically rotated about its axis of rotation at the measurement location. The magnitude of wall shear stress in the vicinity of the corner was observed to increase significantly (170 percent) compared to its far-upstream value; the increase was consistently higher on the blade surface compared to the value on the plate surface of the blade end-wall corner. On both surfaces in the blade end-wall corner, the variation of the wall shear stress direction was found to be more predominant in the vicinity of the blade leading-edge location. The trend of the measured wall shear stress direction showed good agreement with the limiting streamline directions obtained from the flow visualization studies.

  2. Flow Characteristics of Plane Wall Jet with Side Walls on Both Sides

    NASA Astrophysics Data System (ADS)

    Imao, Shigeki; Kikuchi, Satoshi; Kozato, Yasuaki; Hayashi, Takayasu

    Flow characteristics of a two-dimensional jet with side walls have been studied experimentally. Three kinds of cylindrical walls and a flat wall were provided as the side walls, and they were combined and attached to a nozzle. Nine types of side wall conditions were investigated. Velocity was measured by a hot-wire probe and the separation point was measured by a Pitot tube. Mean velocity profiles, the growth of the jet half-width, the decay of jet maximum velocity, and the attachment distance were clarified. When cylindrical walls with different radii are installed, the flow pattern changes markedly depending on the velocity of the jet. A striking increase in the jet half-width is related to the separation of flow from the smaller cylindrical wall just behind the nozzle.

  3. Earthquake resistant structural walls: Test of walls with and without openings

    NASA Astrophysics Data System (ADS)

    Shiu, K. N.; Daniel, J. I.; Aristizabal-Ochoa, J. D.; Fiorato, A. E.; Corley, W. G.

    1981-07-01

    Two one-third scale, six-story wal specimens were subjected to inelastic load reversals representing severe earthquake forces exerted by double acting hydraulic rams, located on both sides of the wall specimens, and applied to the top of each wall. The specimens were designed of earthquake resistant reinforced concrete wall elements in coupled wall systems based on the 1976 Uniform Building Code. The loading was calculated using a modified DRAIN two-dimensional computer program with two actual earthquake records used as input ground motion data. One specimen was a solid wall and the other included six openings simulating windows. When data was normalized by yield capacities, the resonse of the two walls to the inelastic loading was similar. The presence of window openings had little effect on the deformation characteristics of the sample walls in response to the cyclic loads.

  4. Cell Wall Remodeling Enzymes Modulate Fungal Cell Wall Elasticity and Osmotic Stress Resistance.

    PubMed

    Ene, Iuliana V; Walker, Louise A; Schiavone, Marion; Lee, Keunsook K; Martin-Yken, Hélène; Dague, Etienne; Gow, Neil A R; Munro, Carol A; Brown, Alistair J P

    2015-07-28

    The fungal cell wall confers cell morphology and protection against environmental insults. For fungal pathogens, the cell wall is a key immunological modulator and an ideal therapeutic target. Yeast cell walls possess an inner matrix of interlinked β-glucan and chitin that is thought to provide tensile strength and rigidity. Yeast cells remodel their walls over time in response to environmental change, a process controlled by evolutionarily conserved stress (Hog1) and cell integrity (Mkc1, Cek1) signaling pathways. These mitogen-activated protein kinase (MAPK) pathways modulate cell wall gene expression, leading to the construction of a new, modified cell wall. We show that the cell wall is not rigid but elastic, displaying rapid structural realignments that impact survival following osmotic shock. Lactate-grown Candida albicans cells are more resistant to hyperosmotic shock than glucose-grown cells. We show that this elevated resistance is not dependent on Hog1 or Mkc1 signaling and that most cell death occurs within 10 min of osmotic shock. Sudden decreases in cell volume drive rapid increases in cell wall thickness. The elevated stress resistance of lactate-grown cells correlates with reduced cell wall elasticity, reflected in slower changes in cell volume following hyperosmotic shock. The cell wall elasticity of lactate-grown cells is increased by a triple mutation that inactivates the Crh family of cell wall cross-linking enzymes, leading to increased sensitivity to hyperosmotic shock. Overexpressing Crh family members in glucose-grown cells reduces cell wall elasticity, providing partial protection against hyperosmotic shock. These changes correlate with structural realignment of the cell wall and with the ability of cells to withstand osmotic shock. The C. albicans cell wall is the first line of defense against external insults, the site of immune recognition by the host, and an attractive target for antifungal therapy. Its tensile strength is conferred by

  5. Consistently inconsistent, the posterior vaginal wall.

    PubMed

    Hale, Douglass S; Fenner, Dee

    2016-03-01

    Posterior vaginal wall prolapse is one of the most common prolapses encountered by gynecological surgeons. What appears to be a straightforward condition to diagnose and treat surgically for physicians has proven to be frustratingly unpredictable with regard to symptom relief for patients. Functional disorders such as dyssynergic defecation and constipation are often attributed to posterior vaginal wall prolapse. Little scientific evidence supports this assumption, emphasizing that structure and function are not synonymous when treating posterior vaginal wall prolapse. Rectoceles, enteroceles, sigmoidoceles, peritoneoceles, rectal and intraanal intussusception, rectal prolapse, and descending perineal syndrome are all conditions that have an impact on the posterior vaginal wall. All too often these different anatomic conditions are treated with the same surgical approach, addressing a posterior vaginal wall bulge with a traditional posterior colporrhaphy. Studies that examine the correlation between stage of posterior wall prolapse and patient symptoms have failed to reliably do so. Surgical outcomes measured by prolapse staging appear successful, yet patient expectations are often not met. As increasing attention is being placed on patient satisfaction outcomes concerning surgical treatments, this fact will need to be addressed. Surgeons will have to clearly communicate what can and what cannot be expected with surgical repair of posterior vaginal wall prolapse. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Regeneration of near-wall turbulence structures

    NASA Technical Reports Server (NTRS)

    Hamilton, James M.; Kim, John J.; Waleffe, Fabian A.

    1993-01-01

    An examination of the regeneration mechanisms of near-wall turbulence and an attempt to investigate the critical Reynolds number conjecture of Waleffe & Kim is presented. The basis is an extension of the 'minimal channel' approach of Jimenez and Moin which emphasizes the near-wall region and further reduces the complexity of the turbulent flow. Reduction of the flow Reynolds number to the minimum value which will allow turbulence to be sustained has the effect of reducing the ratio of the largest scales to the smallest scales or, equivalently, of causing the near-wall region to fill more of the area between the channel walls. In addition, since each wall may have an active near-wall region, half of the channel is always somewhat redundant. If a plane Couette flow is instead chosen as the base flow, this redundancy is eliminated: the mean shear of a plane Couette flow has a single sign, and at low Reynolds numbers, the two wall regions share a single set of structures. A minimal flow with these modifications possesses, by construction, the strongest constraints which allow sustained turbulence, producing a greatly simplified flow in which the regeneration process can be examined.

  7. 30 years of battling the cell wall.

    PubMed

    Latgé, J P

    2017-01-01

    In Aspergillus fumigatus, like in other pathogenic fungi, the cell wall is essential for fungal growth as well as for resisting environmental stresses such as phagocytic killing. Most of the chemical analyses undertaken on the cell wall of A. fumigatus are focused on the mycelial cell wall because it is the vegetative stage of the fungus. However, the cell walls of the mycelium and conidium (which is the infective propagule) are different especially at the level of the surface layer, which plays a significant role in the interaction between A. fumigatus conidia and phagocytic cells of the immune system. In spite of the essential function of the cell wall in fungal life, progresses have been extremely slow in the understanding of biosynthesis as well in the identification of the key host responses against the cell wall components. A major difficulty is the fact that the composition and structural organization of the cell wall is not immutably set and is constantly reshuffled depending on the environmental conditions. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Rotary press utilizing a flexible die wall.

    PubMed

    Amidon, G E; Smith, D P; Hiestand, E N

    1981-06-01

    A die with a flexible wall was constructed and evaluated on a specially modified instrumented rotary tablet press. The design permits an inward deflection of the die wall by a side punch, which rolls past a side compression roll during compression-decompression. The side compression roll is instrumented to monitor the applied side compression roll forces. On decompression, return of the die wall to its original position permits release of residual die wall pressure. The decreased residual die wall pressure can decrease fracture and capping of tablets for problem formulations. The performance was tested on three experimental formulations. For these formulations, tablets made in a conventional die exhibited severe capping problems. However, most tablets compressed in the special die were superior. With proper adjustment of punch and die wall compression forces, excellent tablets could be manufactured. The merits of the special die and modified tablet machine are substantiated, although this initial design did not provide adequate die wall pressure for all formulations. Further engineering efforts could result in practical production equipment.

  9. Chiral spin torque at magnetic domain walls.

    PubMed

    Ryu, Kwang-Su; Thomas, Luc; Yang, See-Hun; Parkin, Stuart

    2013-07-01

    Spin-polarized currents provide a powerful means of manipulating the magnetization of nanodevices, and give rise to spin transfer torques that can drive magnetic domain walls along nanowires. In ultrathin magnetic wires, domain walls are found to move in the opposite direction to that expected from bulk spin transfer torques, and also at much higher speeds. Here we show that this is due to two intertwined phenomena, both derived from spin-orbit interactions. By measuring the influence of magnetic fields on current-driven domain-wall motion in perpendicularly magnetized Co/Ni/Co trilayers, we find an internal effective magnetic field acting on each domain wall, the direction of which alternates between successive domain walls. This chiral effective field arises from a Dzyaloshinskii-Moriya interaction at the Co/Pt interfaces and, in concert with spin Hall currents, drives the domain walls in lock-step along the nanowire. Elucidating the mechanism for the manipulation of domain walls in ultrathin magnetic films will enable the development of new families of spintronic devices.

  10. Isolation of plant cell wall proteins.

    PubMed

    Jamet, Elisabeth; Boudart, Georges; Borderies, Giséle; Charmont, Stephane; Lafitte, Claude; Rossignol, Michel; Canut, Herve; Pont-Lezica, Rafael

    2008-01-01

    The quality of a proteomic analysis of a cell compartment strongly depends on the reliability of the isolation procedure for the cell compartment of interest. Plant cell walls possess specific drawbacks: (1) the lack of a surrounding membrane may result in the loss of cell wall proteins (CWP) during the isolation procedure; (2) polysaccharide networks of cellulose, hemicelluloses, and pectins form potential traps for contaminants such as intracellular proteins; (3) the presence of proteins interacting in many different ways with the polysaccharide matrix require different procedures to elute them from the cell wall. Three categories of CWP are distinguished: labile proteins that have little or no interactions with cell wall components, weakly bound proteins extractable with salts, and strongly bound proteins. Two alternative protocols are decribed for cell wall proteomics: (1) nondestructive techniques allowing the extraction of labile or weakly bound CWP without damaging the plasma membrane; (2) destructive techniques to isolate cell walls from which weakly or strongly bound CWP can be extracted. These protocols give very low levels of contamination by intracellular proteins. Their application should lead to a realistic view of the cell wall proteome at least for labile and weakly bound CWP extractable by salts.

  11. Recent advances in plant cell wall proteomics.

    PubMed

    Jamet, Elisabeth; Albenne, Cécile; Boudart, Georges; Irshad, Muhammad; Canut, Hervé; Pont-Lezica, Rafael

    2008-02-01

    The plant extracellular matrix contains typical polysaccharides such as cellulose, hemicelluloses, and pectins that interact to form dense interwoven networks. Plant cell walls play crucial roles during development and constitute the first barrier of defense against invading pathogens. Cell wall proteomics has greatly contributed to the description of the protein content of a compartment specific to plants. Around 400 cell wall proteins (CWPs) of Arabidopsis, representing about one fourth of its estimated cell wall proteome, have been described. The main points to note are that: (i) the diversity of enzymes acting on polysaccharides suggests a great plasticity of cell walls; (ii) CWPs such as proteases, polysaccharide hydrolytic enzymes, and lipases may contribute to the generation of signals; (iii) proteins of unknown functions were identified, suggesting new roles for cell walls. Recently, the characterization of PTMs such as N- and O-glycosylations improved our knowledge of CWP structure. The presence of many glycoside hydrolases and proteases suggests a complex regulation of CWPs involving various types of post-translational events. The first 3-D structures to be resolved gave clues about the interactions between CWPs, or between CWPs and polysaccharides. Future work should include: extracting and identifying CWPs still recalcitrant to proteomics, describing the cell wall interactome, improving quantification, and unraveling the roles of each of the CWPs.

  12. Polyphosphorylated fungal cell wall glycopeptides

    SciTech Connect

    Bonetti, S.J.; Black, B.; Gander, J.E.

    1987-05-01

    Penicillium charlesii secretes a 65 kDa peptidophosphogalactomannan (pPGM) containing 10 phosphodiester residues and 10 galactofuranosyl-containing galactin chains attached to a linear mannan; the polysaccharides is attached to a 3 kDa seryl- and threonyl-rich peptide. The authors have now isolated and partially characterized a form of pPGM released from mycelia of P. charlesii treated at 50/sup 0/C for 15, 30, 60 or 120 min. Two- to 3-fold more pPGM was released by heat treatment than is secreted. Crude pPGM, released by heat, was fractionated on DE-52 and was fractionated into two major fractions on the basis of its difference in negative charge. /sup 1/H-decoupled /sup 13/C NMR spectroscopy of these two fractions provided spectra very similar to that of secreted pPGM previously reported from this laboratory. /sup 1/H-decoupled /sup 31/P NMR showed major signals at 1.47, and 0.22 ppm and minor signals at 1.32, 1.15, 1.00, 0.91 and 0.76 ppm. These signals are upfield from phosphomonoesters and are in the region observed for (6-O-phosphorylcholine)- and (6-O-phosphorylethanolamine)-..cap alpha..-D-mannopyranosyl residues which are 0.22 and 0.90 ppm, respectively. These polymers contain 30 phosphodiester residues per molecule of 70 kDa mass compared with 10 phosphodiesters in secreted pPGM. Acid phosphatase and alkaline protease were the only lytic enzymes released by heat treatment. The evidence suggests that much of the pPGM is derived from cell walls; and that the polysaccharide is highly phosphorylated.

  13. Low-cost sustainable wall construction system

    SciTech Connect

    Vohra, A.; Rosenfeld, A.H.

    1998-07-01

    Houses with no wall cavities, such as those made of adobe, stone, brick, or block, have poor thermal properties but are rarely insulated because of the cost and difficulty of providing wall insulation. A simple, low-cost technique using loose-fill indigenous materials has been demonstrated for the construction of highly insulated walls or the retrofit of existing walls in such buildings. Locally available pumice, in sandbags stacked along the exterior wall of an adobe house in New Mexico, added a thermal resistance (R) of 16 F{sm{underscore}bullet}ft{sup 2}{sm{underscore}bullet}h/Btu (2.8 m{sup 2}{sm{underscore}bullet}K/W). The total cost of the sandbag insulation wall retrofit was $3.76 per square foot ($40.50/m{sup 2}). Computer simulations of the adobe house using DOE 2.1E show savings of $275 per year, corresponding to 50% reduction in heating energy consumption. The savings-to-investment ratio ranges from 1.1 to 3.2, so the cost of conserved energy is lower than the price of propane, natural gas and electric heat, making the system cost-effective. Prototype stand-alone walls were also constructed using fly ash and sawdust blown into continuous polypropylene tubing, which was folded between corner posts as it was filled to form the shape of the wall. Other materials could also be used. The inexpensive technique solves the problem of insulating solid-wall hours and constructing new houses without specialized equipment and skills, thereby saving energy, reducing greenhouse gas emissions, and improving comfort for people in many countries. The US Department of Energy (DOE) has filed patent applications on this technology, which is part of a DOE initiative on sustainable building envelope materials and systems.

  14. A wall interference assessment/correction system

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.; Ulbrich, N.; Sickles, W. L.; Qian, Cathy X.

    1992-01-01

    A Wall Signature method, the Hackett method, has been selected to be adapted for the 12-ft Wind Tunnel wall interference assessment/correction (WIAC) system in the present phase. This method uses limited measurements of the static pressure at the wall, in conjunction with the solid wall boundary condition, to determine the strength and distribution of singularities representing the test article. The singularities are used in turn for estimating wall interferences at the model location. The Wall Signature method will be formulated for application to the unique geometry of the 12-ft Tunnel. The development and implementation of a working prototype will be completed, delivered and documented with a software manual. The WIAC code will be validated by conducting numerically simulated experiments rather than actual wind tunnel experiments. The simulations will be used to generate both free-air and confined wind-tunnel flow fields for each of the test articles over a range of test configurations. Specifically, the pressure signature at the test section wall will be computed for the tunnel case to provide the simulated 'measured' data. These data will serve as the input for the WIAC method-Wall Signature method. The performance of the WIAC method then may be evaluated by comparing the corrected parameters with those for the free-air simulation. Each set of wind tunnel/test article numerical simulations provides data to validate the WIAC method. A numerical wind tunnel test simulation is initiated to validate the WIAC methods developed in the project. In the present reported period, the blockage correction has been developed and implemented for a rectangular tunnel as well as the 12-ft Pressure Tunnel. An improved wall interference assessment and correction method for three-dimensional wind tunnel testing is presented in the appendix.

  15. Chest wall hypoplasia--principles and treatment.

    PubMed

    Mayer, Oscar Henry

    2015-01-01

    The chest is a dynamic structure. For normal movement it relies on a coordinated movement of the multiple bones, joints and muscles of the respiratory system. While muscle weakness can have clear impact on respiration by decreasing respiratory motion, so can conditions that cause chest wall hypoplasia and produce an immobile chest wall. These conditions, such as Jarcho-Levin and Jeune syndrome, present significantly different challenges than those faced with early onset scoliosis in which chest wall mechanics and thoracic volume may be much closer to normal. Because of this difference more aggressive approaches to clinical and surgical management are necessary.

  16. Prefabricated brick wall panels: Economy or nightmare?

    SciTech Connect

    Louis, M.J.

    1999-07-01

    Prefabricated wall systems are becoming a popular element of building construction. Prefabricated systems lend themselves to streamlining construction schedules and reducing overall construction costs. They offer the potential for increased quality due to assembly in controlled factory environments. This paper reviews basic principles and concepts for the design of waterproofing systems for prefabricated brick wall panels. Using a project case study, the author will show that failure to adhere to certain proven conventional practices can have serious adverse consequences with respect to the performance of prefabricated brick wall panels.

  17. Soft tissue coverage in abdominal wall reconstruction.

    PubMed

    Baumann, Donald P; Butler, Charles E

    2013-10-01

    Abdominal wall defects requiring soft tissue coverage can be either partial-thickness defects or full-thickness composite defects. Soft tissue flap reconstruction offers significant advantages in defects that cannot be closed primarily. Flap reconstruction is performed in a single-stage procedure obviating chronic wound management. If the defect size exceeds the availability of local soft tissue for coverage, regional pedicled flaps can be delivered into the abdominal wall while maintaining blood supply from their donor site. Microsurgical free tissue transfer increases the capacity to provide soft tissue coverage for abdominal wall defects that are not amenable to either local or regional flap coverage.

  18. Refractive index of plant cell walls

    NASA Technical Reports Server (NTRS)

    Gausman, H. W.; Allen, W. A.; Escobar, D. E.

    1974-01-01

    Air was replaced with media of higher refractive indices by vacuum infiltration in leaves of cucumber, blackeye pea, tomato, and string bean plants, and reflectance of noninfiltrated and infiltrated leaves was spectrophotometrically measured. Infiltrated leaves reflected less light than noninfiltrated leaves over the 500-2500-nm wavelength interval because cell wall-air interfaces were partly eliminated. Minimal reflectance should occur when the average refractive index of plant cell walls was matched by the infiltrating fluid. Although refractive indices that resulted in minimal reflectance differed among the four plant genera, an average value of 1.425 approximates the refractive index of plant cell walls for the four plant genera.

  19. Domain wall orientation in magnetic nanowires.

    PubMed

    Vedmedenko, E Y; Kubetzka, A; von Bergmann, K; Pietzsch, O; Bode, M; Kirschner, J; Oepen, H P; Wiesendanger, R

    2004-02-20

    Scanning tunneling microscopy reveals that domain walls in ultrathin Fe nanowires are oriented along a certain crystallographic direction, regardless of the orientation of the wires. Monte Carlo simulations on a discrete lattice are in accordance with the experiment if the film relaxation is taken into account. We demonstrate that the wall orientation is determined by the atomic lattice and the resulting strength of an effective exchange interaction. The magnetic anisotropy and the magnetostatic energy play a minor role for the wall orientation in that system.

  20. Domain walls and defects in ferroelectric materials

    NASA Astrophysics Data System (ADS)

    Rojac, Tadej; Damjanovic, Dragan

    2017-10-01

    The results of recent studies of domain walls and their interaction with defects in BaTiO3, Pb(Zr,Ti)O3, and BiFeO3 are discussed. The studies reveal why donor- and acceptor-doped Pb(Zr,Ti)O3 behave differently, what is the role of stationary charged domain walls in enhanced properties of domain engineered BaTiO3 crystals, and give evidence of a large concentration of specific charged point defects within domain walls in BiFeO3 ceramics.

  1. Refractive index of plant cell walls

    NASA Technical Reports Server (NTRS)

    Gausman, H. W.; Allen, W. A.; Escobar, D. E.

    1974-01-01

    Air was replaced with media of higher refractive indices by vacuum infiltration in leaves of cucumber, blackeye pea, tomato, and string bean plants, and reflectance of noninfiltrated and infiltrated leaves was spectrophotometrically measured. Infiltrated leaves reflected less light than noninfiltrated leaves over the 500-2500-nm wavelength interval because cell wall-air interfaces were partly eliminated. Minimal reflectance should occur when the average refractive index of plant cell walls was matched by the infiltrating fluid. Although refractive indices that resulted in minimal reflectance differed among the four plant genera, an average value of 1.425 approximates the refractive index of plant cell walls for the four plant genera.

  2. 14. INTERIOR VIEW OF FIREPLACE AND SURROUNDING WALL IN FIRST ...

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

    14. INTERIOR VIEW OF FIREPLACE AND SURROUNDING WALL IN FIRST FLOOR, NORTHWEST PARLOR, NORTH WALL, WITH SCALE (NOTE WALL STENCILING) - George W. Eckhart House, 810 Main Street, Wheeling, Ohio County, WV

  3. Artificial Rock Climbing Walls--Innovative Adventure Environments.

    ERIC Educational Resources Information Center

    Attarian, Aram

    1989-01-01

    The history, advantages, and disadvantages of artificial rock climbing walls (used to instruct individuals in the sport of rock climbing) are discussed. Additional topics include designing an artificial wall, types of walls, various uses, and risk management. (IAH)

  4. 44. DETAIL VIEW OF CONTROL PANEL IN UPPER WEST WALL ...

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

    44. DETAIL VIEW OF CONTROL PANEL IN UPPER WEST WALL CONTROL STATION, LOOKING EAST. UPPER INTERMEDIATE WALL AND UPPER EAST WALL CONTROL STATIONS IN BACKGROUND - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 27, Granite City, Madison County, IL

  5. 8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT ...

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

    8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT THAT SHOWS THE TRENCHING AND 1960 PIPELINE CORRIDOR BETWEEN THE WALL SEGMENTS, LOOKING WEST-NORTHWEST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  6. 15. MASONRY DETAIL NO. 1, NORTH TRAINING WALL, LOOKING DOWN ...

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

    15. MASONRY DETAIL NO. 1, NORTH TRAINING WALL, LOOKING DOWN UPON THE WALL SURFACE FROM THE ADJACENT RIPRAP. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  7. A one piece wall box for space electronics

    SciTech Connect

    Greenwood, W.H.

    1995-05-01

    In extraterrestrial applications, satellite payloads have printed circuit modules that are housed in boxes or chassis. The box may be a one piece wall or a segmented wall. These two wall options are compared for function and cost.

  8. 26. NORTH TRAINING WALL, CLOSE UP VIEW OF EAST SECTION ...

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

    26. NORTH TRAINING WALL, CLOSE UP VIEW OF EAST SECTION SIDE WALL, LOW TIDE. (Panoramic view 2 of 2). - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  9. Artificial Rock Climbing Walls--Innovative Adventure Environments.

    ERIC Educational Resources Information Center

    Attarian, Aram

    1989-01-01

    The history, advantages, and disadvantages of artificial rock climbing walls (used to instruct individuals in the sport of rock climbing) are discussed. Additional topics include designing an artificial wall, types of walls, various uses, and risk management. (IAH)

  10. Disruption of hydrogen bonding between plant cell wall polymers by proteins that induce wall extension.

    PubMed Central

    McQueen-Mason, S; Cosgrove, D J

    1994-01-01

    Plant cell enlargement is controlled by the ability of the constraining cell wall to expand. This ability has been postulated to be under the control of polysaccharide hydrolases or transferases that weaken or rearrange the loadbearing polymeric networks in the wall. We recently identified a family of wall proteins, called expansins, that catalyze the extension of isolated plant cell walls. Here we report that these proteins mechanically weaken pure cellulose paper in extension assays and stress relaxation assays, without detectable cellulase activity (exo- or endo- type). Because paper derives its mechanical strength from hydrogen bonding between cellulose microfibrils, we conclude that expansins can disrupt hydrogen bonding between cellulose fibers. This conclusion is further supported by experiments in which expansin-mediated wall extension (i) was increased by 2 M urea (which should weaken hydrogen bonding between wall polymers) and (ii) was decreased by replacement of water with deuterated water, which has a stronger hydrogen bond. The temperature sensitivity of expansin-mediated wall extension suggests that units of 3 or 4 hydrogen bonds are broken by the action of expansins. In the growing cell wall, expansin action is likely to catalyze slippage between cellulose microfibrils and the polysaccharide matrix, and thereby catalyze wall stress relaxation, followed by wall surface expansion and plant cell enlargement. Images PMID:11607483

  11. Combined Visualization of Wall Thickness and Wall Shear Stress for the Evaluation of Aneurysms.

    PubMed

    Glaßer, Sylvia; Lawonn, Kai; Hoffmann, Thomas; Skalej, Martin; Preim, Bernhard

    2014-12-01

    For an individual rupture risk assessment of aneurysms, the aneurysm's wall morphology and hemodynamics provide valuable information. Hemodynamic information is usually extracted via computational fluid dynamic (CFD) simulation on a previously extracted 3D aneurysm surface mesh or directly measured with 4D phase-contrast magnetic resonance imaging. In contrast, a noninvasive imaging technique that depicts the aneurysm wall in vivo is still not available. Our approach comprises an experiment, where intravascular ultrasound (IVUS) is employed to probe a dissected saccular aneurysm phantom, which we modeled from a porcine kidney artery. Then, we extracted a 3D surface mesh to gain the vessel wall thickness and hemodynamic information from a CFD simulation. Building on this, we developed a framework that depicts the inner and outer aneurysm wall with dedicated information about local thickness via distance ribbons. For both walls, a shading is adapted such that the inner wall as well as its distance to the outer wall is always perceivable. The exploration of the wall is further improved by combining it with hemodynamic information from the CFD simulation. Hence, the visual analysis comprises a brushing and linking concept for individual highlighting of pathologic areas. Also, a surface clustering is integrated to provide an automatic division of different aneurysm parts combined with a risk score depending on wall thickness and hemodynamic information. In general, our approach can be employed for vessel visualization purposes where an inner and outer wall has to be adequately represented.

  12. Wall shear stress manifolds and near wall flow topology in aneurysms

    NASA Astrophysics Data System (ADS)

    Arzani, Amirhossein; Gambaruto, Alberto M.; Chen, Guoning; Shadden, Shawn C.

    2015-11-01

    Transport of atherogenic and thrombogenic chemicals near the vessel wall highly influences atherosclerosis and thrombosis. The high Schmidt number of these species leads to a thin concentration boundary layer near the wall. The wall shear stress (WSS) vector field can be scaled to obtain the near wall velocity in this region, thus providing first order approximation to near wall transport. In this study, the complex blood flow in patient-specific abdominal aortic aneurysms was considered. Lagrangian tracking of surface-bound tracers representing near wall species was employed to identify Lagrangian coherent structures (LCS) for the WSS surface vector field. The WSS LCS matched the stable and unstable manifolds of saddle type fixed points of the time-average WSS vector field, due to the quasi-steady nature of these near wall transport processes. A WSS exposure time measure is introduced to quantify the concentration of near wall species. The effect of diffusion and normal flow on these structures is investigated. The WSS LCS highly influence the concentration of near wall species, and provide a template for near-wall transport.

  13. Cell Wall Remodeling Enzymes Modulate Fungal Cell Wall Elasticity and Osmotic Stress Resistance

    PubMed Central

    Ene, Iuliana V.; Walker, Louise A.; Schiavone, Marion; Lee, Keunsook K.; Martin-Yken, Hélène; Dague, Etienne; Gow, Neil A. R.; Munro, Carol A.

    2015-01-01

    ABSTRACT The fungal cell wall confers cell morphology and protection against environmental insults. For fungal pathogens, the cell wall is a key immunological modulator and an ideal therapeutic target. Yeast cell walls possess an inner matrix of interlinked β-glucan and chitin that is thought to provide tensile strength and rigidity. Yeast cells remodel their walls over time in response to environmental change, a process controlled by evolutionarily conserved stress (Hog1) and cell integrity (Mkc1, Cek1) signaling pathways. These mitogen-activated protein kinase (MAPK) pathways modulate cell wall gene expression, leading to the construction of a new, modified cell wall. We show that the cell wall is not rigid but elastic, displaying rapid structural realignments that impact survival following osmotic shock. Lactate-grown Candida albicans cells are more resistant to hyperosmotic shock than glucose-grown cells. We show that this elevated resistance is not dependent on Hog1 or Mkc1 signaling and that most cell death occurs within 10 min of osmotic shock. Sudden decreases in cell volume drive rapid increases in cell wall thickness. The elevated stress resistance of lactate-grown cells correlates with reduced cell wall elasticity, reflected in slower changes in cell volume following hyperosmotic shock. The cell wall elasticity of lactate-grown cells is increased by a triple mutation that inactivates the Crh family of cell wall cross-linking enzymes, leading to increased sensitivity to hyperosmotic shock. Overexpressing Crh family members in glucose-grown cells reduces cell wall elasticity, providing partial protection against hyperosmotic shock. These changes correlate with structural realignment of the cell wall and with the ability of cells to withstand osmotic shock. PMID:26220968

  14. 97. DAM OPERATING HOUSE WALL SECTION & MISCELLANEOUS ...

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

    97. DAM - OPERATING HOUSE - WALL SECTION & MISCELLANEOUS DETAIL (ML-8-41/2-FS) June 1935 - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

  15. Porins in the Cell Wall of Mycobacteria

    NASA Astrophysics Data System (ADS)

    Trias, Joaquim; Jarlier, Vincent; Benz, Roland

    1992-11-01

    The cell wall of mycobacteria is an efficient permeability barrier that makes mycobacteria naturally resistant to most antibiotics. Liposome swelling assays and planar bilayer experiments were used to investigate the diffusion process of hydrophilic molecules through the cell wall of Mycobacterium chelonae and identify the main hydrophilic pathway. A 59-kilodalton cell wall protein formed a water-filled channel with a diameter of 2.2 nanometers and an average single-channel conductance equal to 2.7 nanosiemens in 1 M potassium chloride. These results suggest that porins can be found in the cell wall of a Gram-positive bacterium. A better knowledge of the hydrophilic pathways should help in the design of more effective antimycobacterial agents.

  16. Axions from cosmic string and wall decay

    SciTech Connect

    Hagmann, C A

    2010-03-10

    If inflation occurred with a reheat temperature > T{sub PQ}, axions from the decay of global axion strings and domain walls would make an important contribution to the cosmological energy density, comparable to that from vacuum misalignment. Several groups have numerically studied the evolution of axion strings and walls in the past, however substantial uncertainties remain in their contribution to the present density {Omega}{sub a,string+wall} {approx} 1-100 (f{sub a}/10{sup 12} GeV){sup 7/6}, where f{sub a} is the axion decay constant. I will describe the numerical methods used in our simulations and show results for several string and wall configurations.

  17. On thick domain walls in general relativity

    NASA Technical Reports Server (NTRS)

    Goetz, Guenter; Noetzold, Dirk

    1989-01-01

    Planar scalar field configurations in general relativity differ considerably from those in flat space. It is shown that static domain walls of finite thickness in curved space-time do not possess a reflection symmetry. At infinity, the space-time tends to the Taub vacuum on one side of the wall and to the Minkowski vacuum (Rindler space-time) on the other. Massive test particles are always accelerated towards the Minkowski side, i.e., domain walls are attractive on the Taub side, but repulsive on the Minkowski side (Taub-vacuum cleaner). It is also proved that the pressure in all directions is always negative. Finally, a brief comment is made concerning the possibility of infinite, i.e., bigger than horizon size, domain walls in our universe. All of the results are independent of the form of the potential V(phi) greater than or equal to 0 of the scalar field phi.

  18. Accurate Wall Loss Determination in Accelerator Design

    SciTech Connect

    Ge, L

    2004-05-13

    While the parallel finite element eigensolver Omega3P has shown to be able to calculate RF cavity mode frequencies to very high precision, it has become increasingly necessary that wall loss be determined with high accuracy as well because: (1) the wall loss leads to shunt impedance degradation and (2) excessive wall loss results in undesirable RF pulse heating. These issues need to be adequately addressed in next generation accelerators such as the NLC in which accelerator structures are designed to operate at high efficiency and high power. This paper will present results from an ongoing effort to improve wall loss calculations with Omega3P and with a new parallel S-matrix solver S3P through higher order mesh elements and adaptive refinement strategies.

  19. Dynamical depinning of chiral domain walls

    NASA Astrophysics Data System (ADS)

    Moretti, Simone; Voto, Michele; Martinez, Eduardo

    2017-08-01

    The domain wall depinning field represents the minimum magnetic field needed to move a domain wall, typically pinned by samples' disorder or patterned constrictions. Conventionally, such a field is considered independent on the Gilbert damping since it is assumed to be the field at which the Zeeman energy equals the pinning energy barrier (both damping independent). Here we analyze numerically the domain wall depinning field as a function of the Gilbert damping in a system with perpendicular magnetic anisotropy and Dzyaloshinskii-Moriya interaction. Contrary to expectations, we find that the depinning field depends on the Gilbert damping and that it strongly decreases for small damping parameters. We explain this dependence with a simple one-dimensional model and we show that the reduction of the depinning field is related to the finite size of the pinning barriers and to the domain wall internal dynamics, connected to the Dzyaloshinskii-Moriya interaction and the shape anisotropy.

  20. Cell wall remodeling under abiotic stress

    PubMed Central

    Tenhaken, Raimund

    2015-01-01

    Plants exposed to abiotic stress respond to unfavorable conditions on multiple levels. One challenge under drought stress is to reduce shoot growth while maintaining root growth, a process requiring differential cell wall synthesis and remodeling. Key players in this process are the formation of reactive oxygen species (ROS) and peroxidases, which initially cross-link phenolic compounds and glycoproteins of the cell walls causing stiffening. The function of ROS shifts after having converted all the peroxidase substrates in the cell wall. If ROS-levels remain high during prolonged stress, OH°-radicals are formed which lead to polymer cleavage. In concert with xyloglucan modifying enzymes and expansins, the resulting cell wall loosening allows further growth of stressed organs. PMID:25709610

  1. Crystallinity of lyophilised carrot cell wall components.

    PubMed

    Georget, D M; Cairns, P; Smith, A C; Waldron, K W

    1999-12-15

    The aim of this work was to investigate the effect of removal of cell wall components on the crystallinity of cell walls using X-ray diffraction. Various insoluble cell wall residues were prepared following a sequential extraction of carrot cell wall material. X-ray diffraction patterns were typical of cellulose although there was a possible contribution of pectic polysaccharides to the crystallinity. As more amorphous material was removed to produce a cellulose rich residue, the crystallinity index increased from 12 to 16%, larger than that estimated from cellulose alone. For the last residue treated with 4M KOH, a lower value of crystallinity was found (14%) which resulted from the change of some crystalline domains of cellulose into amorphous regions. Pressing conditions (temperature, water content) have been investigated and did not alter the crystallinity index significantly.

  2. Wall Paint Exposure Assessment Model (WPEM)

    EPA Pesticide Factsheets

    WPEM uses mathematical models developed from small chamber data to estimate the emissions of chemicals from oil-based (alkyd) and latex wall paint which is then combined with detailed use, workload and occupancy data to estimate user exposure.

  3. Domain wall magneto-Seebeck effect

    NASA Astrophysics Data System (ADS)

    Krzysteczko, Patryk; Hu, Xiukun; Liebing, Niklas; Sievers, Sibylle; Schumacher, Hans W.

    2015-10-01

    The interplay between charge, spin, and heat currents in magnetic nanostructures subjected to a temperature gradient has led to a variety of novel effects and promising applications studied in the fast-growing field of spin caloritronics. Here, we explore the magnetothermoelectrical properties of an individual magnetic domain wall in a permalloy nanowire. In thermal gradients of the order of few K /μ m along the long wire axis, we find a clear magneto-Seebeck signature due to the presence of a single domain wall. The observed domain wall magneto-Seebeck effect can be explained by the magnetization-dependent Seebeck coefficient of permalloy in combination with the local spin configuration of the domain wall.

  4. Wall System Saves Initial HVAC Costs

    ERIC Educational Resources Information Center

    Modern Schools, 1976

    1976-01-01

    The superior insulating characteristics of an exterior wall system has enabled a Massachusetts school district to realize a savings on electric heating, ventilating, and air-conditioning systems. (Author/MLF)

  5. Development and pathologies of the arterial wall.

    PubMed

    Seidelmann, Sara B; Lighthouse, Janet K; Greif, Daniel M

    2014-06-01

    Arteries consist of an inner single layer of endothelial cells surrounded by layers of smooth muscle and an outer adventitia. The majority of vascular developmental studies focus on the construction of endothelial networks through the process of angiogenesis. Although many devastating vascular diseases involve abnormalities in components of the smooth muscle and adventitia (i.e., the vascular wall), the morphogenesis of these layers has received relatively less attention. Here, we briefly review key elements underlying endothelial layer formation and then focus on vascular wall development, specifically on smooth muscle cell origins and differentiation, patterning of the vascular wall, and the role of extracellular matrix and adventitial progenitor cells. Finally, we discuss select human diseases characterized by marked vascular wall abnormalities. We propose that continuing to apply approaches from developmental biology to the study of vascular disease will stimulate important advancements in elucidating disease mechanism and devising novel therapeutic strategies.

  6. Radial construction of an arterial wall.

    PubMed

    Greif, Daniel M; Kumar, Maya; Lighthouse, Janet K; Hum, Justine; An, Andrew; Ding, Ling; Red-Horse, Kristy; Espinoza, F Hernan; Olson, Lorin; Offermanns, Stefan; Krasnow, Mark A

    2012-09-11

    Some of the most serious diseases involve altered size and structure of the arterial wall. Elucidating how arterial walls are built could aid understanding of these diseases, but little is known about how concentric layers of muscle cells and the outer adventitial layer are assembled and patterned around endothelial tubes. Using histochemical, clonal, and genetic analysis in mice, here we show that the pulmonary artery wall is constructed radially, from the inside out, by two separate but coordinated processes. One is sequential induction of successive cell layers from surrounding mesenchyme. The other is controlled invasion of outer layers by inner layer cells through developmentally regulated cell reorientation and radial migration. We propose that a radial signal gradient controls these processes and provide evidence that PDGF-B and at least one other signal contribute. Modulation of such radial signaling pathways may underlie vessel-specific differences and pathological changes in arterial wall size and structure.

  7. Wall and Terrace at Marcia Crater

    NASA Image and Video Library

    2012-03-21

    This image from NASA Dawn spacecraft shows an interior wall and southern terrace of Marcia crater on Vesta. Relatively smooth material covers much of the terrace and has flowed downslope toward the top of the image through channels.

  8. Portable Data Wall Transition To Production

    DTIC Science & Technology

    2004-03-01

    Displays, Human - Computer Interaction , Data Wall 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT UNCLASSIFIED 18. SECURITY CLASSIFICATION...wireless Human - Computer Interaction (HCI) capabilities which allow massive amounts of information available to the warfighters to be displayed to large

  9. Wall System Saves Initial HVAC Costs

    ERIC Educational Resources Information Center

    Modern Schools, 1976

    1976-01-01

    The superior insulating characteristics of an exterior wall system has enabled a Massachusetts school district to realize a savings on electric heating, ventilating, and air-conditioning systems. (Author/MLF)

  10. Cell Wall Assembly in Saccharomyces cerevisiae

    PubMed Central

    Lesage, Guillaume; Bussey, Howard

    2006-01-01

    An extracellular matrix composed of a layered meshwork of β-glucans, chitin, and mannoproteins encapsulates cells of the yeast Saccharomyces cerevisiae. This organelle determines cellular morphology and plays a critical role in maintaining cell integrity during cell growth and division, under stress conditions, upon cell fusion in mating, and in the durable ascospore cell wall. Here we assess recent progress in understanding the molecular biology and biochemistry of cell wall synthesis and its remodeling in S. cerevisiae. We then review the regulatory dynamics of cell wall assembly, an area where functional genomics offers new insights into the integration of cell wall growth and morphogenesis with a polarized secretory system that is under cell cycle and cell type program controls. PMID:16760306

  11. Applications of Green Walls in Urban Design

    NASA Astrophysics Data System (ADS)

    Virtudes, Ana; Manso, Maria

    2016-10-01

    Green walls are a choice towards achieving sustainable urban rehabilitation, due to the lack of free space in the consolidated urban fabric. Nowadays, green walls are considered to be an innovation in the fields of ecology, horticulture or buildings. Nevertheless, in the domain of urban design, they are still surprising and unexpected ideas. Thus, this research aims to reflect on green walls as a feature in urban design and rehabilitation, identifying the advantages of their utilization as an enhancement of the quality of city's image, especially in dense urban areas. It aims to demonstrate some practical applications of green walls in urban design proposals, showing model solutions and their real application in several architectural examples.

  12. Static inelastic analysis of RC shear walls

    NASA Astrophysics Data System (ADS)

    Chen, Qin; Qian, Jiaru

    2002-06-01

    A macro-model of a reinforced concrete (RC) shear wall is developed for static inelastic analysis. The model is composed of RC column elements and RC membrane elements. The column elements are used to model the boundary zone and the membrane elements are used to model the wall panel. Various types of constitutive relationships of concrete could be adopted for the two kinds of elements. To perform analysis, the wall is divided into layers along its height. Two adjacent layers are connected with a rigid beam. There are only three unknown displacement components for each layer. A method called single degree of freedom compensation is adopted to solve the peak value of the capacity curve. The post-peak stage analysis is performed using a forced iteration approach. The macro-model developed in the study and the complete process analysis methodology are verified by the experimental and static inelastic analytical results of four RC shear wall specimens.

  13. Domain walls as probes of gravity

    SciTech Connect

    Dvali, Gia; Gabadadze, Gregory; Pujolas, Oriol; Rahman, Rakibur

    2007-06-15

    We show that domain walls are probes that enable one to distinguish large-distance modified gravity from general relativity (GR) at short distances. For example, low-tension domain walls are stealth in modified gravity, while they do produce global gravitational effects in GR. We demonstrate this by finding exact solutions for various domain walls in the DGP model. A wall with tension lower than the fundamental Planck scale does not inflate and has no gravitational effects on a 4D observer, since its 4D tension is completely screened by gravity itself. We argue that this feature remains valid in a generic class of models of infrared modified gravity. As a byproduct, we obtain exact solutions for supermassive codimension-2 branes.

  14. Functional duality of the cell wall.

    PubMed

    Latgé, Jean-Paul; Beauvais, Anne

    2014-08-01

    The polysaccharide cell wall is the extracellular armour of the fungal cell. Although essential in the protection of the fungal cell against aggressive external stresses, the biosynthesis of the polysaccharide core is poorly understood. For a long time it was considered that this cell wall skeleton was a fixed structure whose role was only to be sensed as non-self by the host and consequently trigger the defence response. It is now known that the cell wall polysaccharide composition and localization continuously change to adapt to their environment and that these modifications help the fungus to escape from the immune system. Moreover, cell wall polysaccharides could function as true virulence factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. 4. BASEMENT WALL BENEATH SOUTH PASSAGE SHOWING STEAM TUNNEL OPENING ...

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

    4. BASEMENT WALL BENEATH SOUTH PASSAGE SHOWING STEAM TUNNEL OPENING IN SOUTH WALL. - Pennsylvania Railroad Station, South Baggage Passage & Canopy, 1101 Liberty Avenue, Pittsburgh, Allegheny County, PA

  16. Cell wall proteins: a new insight through proteomics.

    PubMed

    Jamet, Elisabeth; Canut, Hervé; Boudart, Georges; Pont-Lezica, Rafael F

    2006-01-01

    Cell wall proteins are essential constituents of plant cell walls; they are involved in modifications of cell wall components, wall structure, signaling and interactions with plasma membrane proteins at the cell surface. The application of proteomic approaches to the cell wall compartment raises important questions: are there technical problems specific to cell wall proteomics? What kinds of proteins can be found in Arabidopsis walls? Are some of them unexpected? What sort of post-translational modifications have been characterized in cell wall proteins to date? The purpose of this review is to discuss the experimental results obtained to date using proteomics, as well as some of the new questions challenging future research.

  17. Shock Tunnel Tests of Arched Wall Panels

    DTIC Science & Technology

    1974-07-01

    buildings which contain designated fallout shelter spaces. Brittle materials, such as brick and concrete block, were the primary materials...have walls constructed of brittle materials, such as brick and concrete block, these have been the primary materials investi- gated . PROCEDURE...reporting period was on shock tunnel tests of walls made of brittle ma- terial (brick and concrete block) and supporting analytical effort. How- ever

  18. INTOR impurity control and first wall system

    SciTech Connect

    Abdou, M.A.

    1983-04-01

    The highlights of the recent INTOR effort on examining the key issues of the impurity control/first wall system are summarized. The emphasis of the work was an integrated study of the edge-region physics, plasma-wall interaction, materials, engineering and magnetic considerations associated with the poloidal divertor and pump limiter. The development of limiter and divertor collector plate designs with an acceptable lifetime was a major part of the work.

  19. Effect of shear on duct wall impedance.

    NASA Technical Reports Server (NTRS)

    Goldstein, M.; Rice, E.

    1973-01-01

    The solution to the equation governing the propagation of sound in a uniform shear layer is expressed in terms of parabolic cylinder functions. This result is used to develop a closed-form solution for acoustic wall impedance which accounts for both the duct liner and the presence of a boundary layer in the duct. The effective wall impedance can then be used as the boundary condition for the much simpler problem of sound propagation in uniform flow.

  20. Thin Wall Cast Iron: Phase II

    SciTech Connect

    Doru M. Stefanescu

    2005-07-21

    The development of thin-wall technology allows the designers of energy consuming equipment to select the most appropriate material based on cost/material properties considerations, and not solely on density. The technology developed in this research project will permit the designers working for the automotive industry to make a better informed choice between competing materials and thin wall cast iron, thus decreasing the overall cost of the automobile.

  1. Shear wall experiments and design in Japan

    SciTech Connect

    Park, Y.J.; Hofmayer, C.

    1994-12-01

    This paper summarizes the results of recent survey studies on the available experimental data bases and design codes/standards for reinforced concrete (RC) shear wall structures in Japan. Information related to the seismic design of RC reactor buildings and containment structures was emphasized in the survey. The seismic requirements for concrete structures, particularly those related to shear strength design, are outlined. Detailed descriptions are presented on the development of Japanese shear wall equations, design requirements for containment structures, and ductility requirements.

  2. Cheaper Fabrication Of Tube-Wall Components

    NASA Technical Reports Server (NTRS)

    Bales, Daniel A.; Joyce, James R.

    1993-01-01

    Relatively inexpensive method of forming metal tubes into wall component devised. One initially selects ordinary, imprecisely dimensioned tubes having passed both pressure test and inspections for wall thickness and surface imperfections, and tubes bonded to each other in shorter, simpler procedure. Eliminates need for progressive die forming and attendant inspections after forming steps. Also applicable in fabrication of heat exchangers and other unitary assemblies of tubes.

  3. Cheaper Fabrication Of Tube-Wall Components

    NASA Technical Reports Server (NTRS)

    Bales, Daniel A.; Joyce, James R.

    1993-01-01

    Relatively inexpensive method of forming metal tubes into wall component devised. One initially selects ordinary, imprecisely dimensioned tubes having passed both pressure test and inspections for wall thickness and surface imperfections, and tubes bonded to each other in shorter, simpler procedure. Eliminates need for progressive die forming and attendant inspections after forming steps. Also applicable in fabrication of heat exchangers and other unitary assemblies of tubes.

  4. Outcomes of surgery for chest wall sarcomas.

    PubMed

    Putnam, Joe B

    2010-11-01

    Chest wall resection requires wide local excision, negative margins, and adequate reconstruction. Outcomes are generally good to excellent with wide local excision and negative margins. Mortality is nearly 0% to 1% with mild morbidity. Multispecialty surgical teams may be required for more complex situations. Early diagnosis of chest wall sarcomas, confirmation by an experienced sarcoma pathologist, and multidisciplinary discussion before treatment initiation, are all required for optimal and successful therapy.

  5. Residual interference and wind tunnel wall adaption

    NASA Technical Reports Server (NTRS)

    Mokry, Miroslav

    1989-01-01

    Measured flow variables near the test section boundaries, used to guide adjustments of the walls in adaptive wind tunnels, can also be used to quantify the residual interference. Because of a finite number of wall control devices (jacks, plenum compartments), the finite test section length, and the approximation character of adaptation algorithms, the unconfined flow conditions are not expected to be precisely attained even in the fully adapted stage. The procedures for the evaluation of residual wall interference are essentially the same as those used for assessing the correction in conventional, non-adaptive wind tunnels. Depending upon the number of flow variables utilized, one can speak of one- or two-variable methods; in two dimensions also of Schwarz- or Cauchy-type methods. The one-variable methods use the measured static pressure and normal velocity at the test section boundary, but do not require any model representation. This is clearly of an advantage for adaptive wall test section, which are often relatively small with respect to the test model, and for the variety of complex flows commonly encountered in wind tunnel testing. For test sections with flexible walls the normal component of velocity is given by the shape of the wall, adjusted for the displacement effect of its boundary layer. For ventilated test section walls it has to be measured by the Calspan pipes, laser Doppler velocimetry, or other appropriate techniques. The interface discontinuity method, also described, is a genuine residual interference assessment technique. It is specific to adaptive wall wind tunnels, where the computation results for the fictitious flow in the exterior of the test section are provided.

  6. Wall Climbing Micro Ground Vehicle (MGV)

    DTIC Science & Technology

    2013-09-01

    Wall Climbing Micro Ground Vehicle (MGV) by Ian Bryant, Howard Carpenter, Asha Hall, and Mark Bundy ARL-TR-6628 September 2013...Destroy this report when it is no longer needed. Do not return it to the originator. Army Research Laboratory Aberdeen Proving Ground , MD 21005...ARL-TR-6628 September 2013 Wall Climbing Micro Ground Vehicle (MGV) Ian Bryant, Howard Carpenter, Asha Hall, and Mark Bundy Vehicle

  7. Changes in wall shear stresses in abdominal aortic aneurysms with increasing wall stiffness

    NASA Astrophysics Data System (ADS)

    Salsac, Anne-Virginie; Fernandez, Miguel

    2006-11-01

    During the growth of abdominal aortic aneurysms, local changes occur in the composition and structure of the diseased wall, resulting in its stiffening. A numerical simulation of the fluid structure interactions is performed in idealized models of aneurysms using a finite element method. A full coupling of the equations governing the pulsatile blood flow and the deformation of the compliant wall is undertaken. The effect of the progressive stiffening of the wall is analyzed at various stages in the growth of the aneurysm. Increasing the wall stiffness alters the distribution of wall shear stresses and leads to an increase in their magnitude. The wall compliance is shown to have a more pronounced effect on non-axisymmetric aneurysms, which sustain large displacements. The overall movement of the aneurysm models increases the three-dimensionality of the flow.

  8. Role of cell wall deconstructing enzymes in the proanthocyanidin-cell wall adsorption-desorption phenomena.

    PubMed

    Castro-López, Liliana del Rocío; Gómez-Plaza, Encarna; Ortega-Regules, Ana; Lozada, Daniel; Bautista-Ortín, Ana Belén

    2016-04-01

    The transference of proanthocyanidins from grapes to wine is quite low. This could be due, among other causes, to proanthocyanidins being bound to grape cell wall polysaccharides, which are present in high concentrations in the must. Therefore, the effective extraction of proanthocyanidins from grapes will depend on the ability to disrupt these associations, and, in this respect, enzymes that degrade these polysaccharides could play an important role. The main objective of this work was to test the behavior of proanthocyanidin-cell wall interactions when commercial maceration enzymes are present in the solution. The results showed that cell wall polysaccharides adsorbed a high amount of proanthocyanidins and only a limited quantity of proanthocyanidins could be desorbed from the cell walls after washing with a model solution. The presence of enzymes in the solution reduced the proanthocyanidin-cell wall interaction, probably through the elimination of pectins from the cell wall network.

  9. Dynamic response of flexible retaining walls

    SciTech Connect

    Younan, A.H.; Veletsos, A.S.; Bandyopadhyay, K.

    1997-01-01

    Making use of an extension of a recently proposed, relatively simple, approximate method of analysis, a critical evaluation is made of the response to horizontal ground shaking of flexible walls retaining a uniform, linear, viscoelastic stratum of constant thickness and semiinfinite extent in the horizontal direction. Both cantilever and top-supported walls are examined. Following a detailed description of the method and of its rate of convergence, comprehensive numerical solutions are presented that elucidate the action of the system and the effects of the various parameters involved. The parameters varied include the flexibility of the wall, the condition of top support, and the characteristics of the ground motion. The effects of both harmonic base motions and an actual earthquake record are examined. Special attention is paid to the effects of long-period, effectively static excitations. A maximum dynamic response is then expressed as the product of the corresponding static response and an appropriate amplification or deamplification factor. The response quantities examined include the displacements of the wall relative to the moving base, the dynamic wall pressures, and the total wall force, base shear and base moment.

  10. Wall shear stress in collapsed tubes

    NASA Astrophysics Data System (ADS)

    Naili, S.; Ribreau, C.

    1999-01-01

    A small flexural wall rigidity brings unique features to cross-sectional shapes and blood flow within veins, which are characterised by a non-uniform hemodynamical environment acting upon endothelial cells. Velocity fields and related wall shear stress were numerically determined for a large number of conditions, assuming a fully developed, steady, incompressible laminar flow through an uniform smooth pipe with a constant cross-section. It was shown that the flatness greatly influences the resulting distribution of the wall shear stresses along the lumen perimeter. For instance, under a steady longitudinal pressure gradient at about 500 Pascal per meter inside a constant oval-shaped tube, with a lumen perimeter of the order of 5 × 10^{-2} meter, the maximum wall shear stress is found at about 2 Pascal where the local curvature is minimal. On the other hand, the minimal wall shear stress of the order of 1 Pascal is found where the local curvature is maximal. Clear indications have been reported showing that the hemodynamical wall shear stress does alter endothelial cell morphology and orientation. These results are being used for developing an experimental set-up in order to locally map out the characteristic shear stresses looking for endothelial shape modifications whenever a viscous fluid flow is applied.

  11. Robust ferromagnetism carried by antiferromagnetic domain walls

    NASA Astrophysics Data System (ADS)

    Hirose, Hishiro T.; Yamaura, Jun-Ichi; Hiroi, Zenji

    2017-02-01

    Ferroic materials, such as ferromagnetic or ferroelectric materials, have been utilized as recording media for memory devices. A recent trend for downsizing, however, requires an alternative, because ferroic orders tend to become unstable for miniaturization. The domain wall nanoelectronics is a new developing direction for next-generation devices, in which atomic domain walls, rather than conventional, large domains themselves, are the active elements. Here we show that atomically thin magnetic domain walls generated in the antiferromagnetic insulator Cd2Os2O7 carry unusual ferromagnetic moments perpendicular to the wall as well as electron conductivity: the ferromagnetic moments are easily polarized even by a tiny field of 1 mT at high temperature, while, once cooled down, they are surprisingly robust even in an inverse magnetic field of 7 T. Thus, the magnetic domain walls could serve as a new-type of microscopic, switchable and electrically readable magnetic medium which is potentially important for future applications in the domain wall nanoelectronics.

  12. Robust ferromagnetism carried by antiferromagnetic domain walls

    PubMed Central

    Hirose, Hishiro T.; Yamaura, Jun-ichi; Hiroi, Zenji

    2017-01-01

    Ferroic materials, such as ferromagnetic or ferroelectric materials, have been utilized as recording media for memory devices. A recent trend for downsizing, however, requires an alternative, because ferroic orders tend to become unstable for miniaturization. The domain wall nanoelectronics is a new developing direction for next-generation devices, in which atomic domain walls, rather than conventional, large domains themselves, are the active elements. Here we show that atomically thin magnetic domain walls generated in the antiferromagnetic insulator Cd2Os2O7 carry unusual ferromagnetic moments perpendicular to the wall as well as electron conductivity: the ferromagnetic moments are easily polarized even by a tiny field of 1 mT at high temperature, while, once cooled down, they are surprisingly robust even in an inverse magnetic field of 7 T. Thus, the magnetic domain walls could serve as a new-type of microscopic, switchable and electrically readable magnetic medium which is potentially important for future applications in the domain wall nanoelectronics. PMID:28195565

  13. From soft walls to infrared branes

    SciTech Connect

    Gersdorff, Gero von

    2010-10-15

    Five-dimensional warped spaces with soft walls are generalizations of the standard Randall-Sundrum compactifications, where instead of an infrared brane one has a curvature singularity (with vanishing warp factor) at finite proper distance in the bulk. We project the physics near the singularity onto a hypersurface located a small distance away from it in the bulk. This results in a completely equivalent description of the soft wall in terms of an effective infrared brane, hiding any singular point. We perform explicitly this calculation for two classes of soft wall backgrounds used in the literature. The procedure has several advantages. It separates in a clean way the physics of the soft wall from the physics of the five-dimensional bulk, facilitating a more direct comparison with standard two-brane warped compactifications. Moreover, consistent soft walls show a sort of universal behavior near the singularity which is reflected in the effective brane Lagrangian. Thirdly, for many purposes, a good approximation is obtained by assuming the bulk background away from the singularity to be the usual Randall-Sundrum metric, thus making the soft wall backgrounds better analytically tractable. We check the validity of this procedure by calculating the spectrum of bulk fields and comparing it to the exact result, finding very good agreement.

  14. Tunable inertia of chiral magnetic domain walls

    NASA Astrophysics Data System (ADS)

    Torrejon, Jacob; Martinez, Eduardo; Hayashi, Masamitsu

    2016-11-01

    The time it takes to accelerate an object from zero to a given velocity depends on the applied force and the environment. If the force ceases, it takes exactly the same time to completely decelerate. A magnetic domain wall is a topological object that has been observed to follow this behaviour. Here we show that acceleration and deceleration times of chiral Neel walls driven by current are different in a system with low damping and moderate Dzyaloshinskii-Moriya exchange constant. The time needed to accelerate a domain wall with current via the spin Hall torque is much faster than the time it needs to decelerate once the current is turned off. The deceleration time is defined by the Dzyaloshinskii-Moriya exchange constant whereas the acceleration time depends on the spin Hall torque, enabling tunable inertia of chiral domain walls. Such unique feature of chiral domain walls can be utilized to move and position domain walls with lower current, key to the development of storage class memory devices.

  15. Tunable inertia of chiral magnetic domain walls.

    PubMed

    Torrejon, Jacob; Martinez, Eduardo; Hayashi, Masamitsu

    2016-11-24

    The time it takes to accelerate an object from zero to a given velocity depends on the applied force and the environment. If the force ceases, it takes exactly the same time to completely decelerate. A magnetic domain wall is a topological object that has been observed to follow this behaviour. Here we show that acceleration and deceleration times of chiral Neel walls driven by current are different in a system with low damping and moderate Dzyaloshinskii-Moriya exchange constant. The time needed to accelerate a domain wall with current via the spin Hall torque is much faster than the time it needs to decelerate once the current is turned off. The deceleration time is defined by the Dzyaloshinskii-Moriya exchange constant whereas the acceleration time depends on the spin Hall torque, enabling tunable inertia of chiral domain walls. Such unique feature of chiral domain walls can be utilized to move and position domain walls with lower current, key to the development of storage class memory devices.

  16. Stable charged antiparallel domain walls in hyperferroelectrics

    NASA Astrophysics Data System (ADS)

    Liu, S.; Cohen, R. E.

    2017-06-01

    Charge-neutral 180° domain walls that separate domains of antiparallel polarization directions are common structural topological defects in ferroelectrics. In normal ferroelectrics, charged 180° domain walls running perpendicular to the polarization directions are highly energetically unfavorable because of the depolarization field and are difficult to stabilize. We explore both neutral and charged 180° domain walls in hyperferroelectrics, a class of proper ferroelectrics with persistent polarization in the presence of a depolarization field, using density functional theory. We obtain zero temperature equilibrium structures of head-to-head and tail-to-tail walls in recently discovered ABC-type hexagonal hyperferroelectrics. Charged domain walls can also be stabilized in canonical ferroelectrics represented by LiNbO3 without any dopants, defects or mechanical clamping. First-principles electronic structure calculations show that charged domain walls can reduce and even close the band gap of host materials and support quasi-two-dimensional electron(hole) gas with enhanced electrical conductivity.

  17. Tunable inertia of chiral magnetic domain walls

    PubMed Central

    Torrejon, Jacob; Martinez, Eduardo; Hayashi, Masamitsu

    2016-01-01

    The time it takes to accelerate an object from zero to a given velocity depends on the applied force and the environment. If the force ceases, it takes exactly the same time to completely decelerate. A magnetic domain wall is a topological object that has been observed to follow this behaviour. Here we show that acceleration and deceleration times of chiral Neel walls driven by current are different in a system with low damping and moderate Dzyaloshinskii–Moriya exchange constant. The time needed to accelerate a domain wall with current via the spin Hall torque is much faster than the time it needs to decelerate once the current is turned off. The deceleration time is defined by the Dzyaloshinskii–Moriya exchange constant whereas the acceleration time depends on the spin Hall torque, enabling tunable inertia of chiral domain walls. Such unique feature of chiral domain walls can be utilized to move and position domain walls with lower current, key to the development of storage class memory devices. PMID:27882932

  18. Robust ferromagnetism carried by antiferromagnetic domain walls.

    PubMed

    Hirose, Hishiro T; Yamaura, Jun-Ichi; Hiroi, Zenji

    2017-02-14

    Ferroic materials, such as ferromagnetic or ferroelectric materials, have been utilized as recording media for memory devices. A recent trend for downsizing, however, requires an alternative, because ferroic orders tend to become unstable for miniaturization. The domain wall nanoelectronics is a new developing direction for next-generation devices, in which atomic domain walls, rather than conventional, large domains themselves, are the active elements. Here we show that atomically thin magnetic domain walls generated in the antiferromagnetic insulator Cd2Os2O7 carry unusual ferromagnetic moments perpendicular to the wall as well as electron conductivity: the ferromagnetic moments are easily polarized even by a tiny field of 1 mT at high temperature, while, once cooled down, they are surprisingly robust even in an inverse magnetic field of 7 T. Thus, the magnetic domain walls could serve as a new-type of microscopic, switchable and electrically readable magnetic medium which is potentially important for future applications in the domain wall nanoelectronics.

  19. A wall interference assessment/correction system

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.; Overby, Glenn; Qian, Cathy X.; Sickles, W. L.; Ulbrich, N.

    1992-01-01

    A Wall Signature method originally developed by Hackett has been selected to be adapted for the Ames 12-ft Wind Tunnel WIAC system in the project. This method uses limited measurements of the static pressure at the wall, in conjunction with the solid wall boundary condition, to determine the strength and distribution of singularities representing the test article. The singularities are used in turn for estimating blockage wall interference. The lifting interference will be treated separately by representing in a horseshoe vortex system for the model's lifting effects. The development and implementation of a working prototype will be completed, delivered and documented with a software manual. The WIAC code will be validated by conducting numerically simulated experiments rather than actual wind tunnel experiments. The simulations will be used to generate both free-air and confined wind-tunnel flow fields for each of the test articles over a range of test configurations. Specifically, the pressure signature at the test section wall will be computed for the tunnel case to provide the simulated 'measured' data. These data will serve as the input for the WIAC method--Wall Signature method. The performance of the WIAC method then may be evaluated by comparing the corrected data with those of the free-air simulation.

  20. Noninvasive Stiffness Sensing of Ventricular Wall Based on a Thick-walled Cylinder Model

    NASA Astrophysics Data System (ADS)

    Higashimori, Mitsuru; Ojio, Takeshi; Takeda, Yasuharu; Sakata, Yasushi; Yamamoto, Kazuhiro; Kaneko, Makoto

    This paper discusses a concept of a noninvasive sensing method that can estimate a left ventricular wall stiffness towards a medical diagnosis. Focusing on not only the strain of ventricular wall but also the displacements of epicardium during diastole of heart beat, we propose an index of ventricular wall stiffness based on a thick-walled cylinder model. Applying the proposed method to the echocardiography, we show statistical results where normal and HFpEF (Heart Failure with preserved Ejection Fraction) can be separated towards a medical diagnosis.

  1. Adaptive wall technology for minimization of wall interferences in transonic wind tunnels

    NASA Technical Reports Server (NTRS)

    Wolf, Stephen W. D.

    1988-01-01

    Modern experimental techniques to improve free air simulations in transonic wind tunnels by use of adaptive wall technology are reviewed. Considered are the significant advantages of adaptive wall testing techniques with respect to wall interferences, Reynolds number, tunnel drive power, and flow quality. The application of these testing techniques relies on making the test section boundaries adjustable and using a rapid wall adjustment procedure. A historical overview shows how the disjointed development of these testing techniques, since 1938, is closely linked to available computer support. An overview of Adaptive Wall Test Section (AWTS) designs shows a preference for use of relatively simple designs with solid adaptive walls in 2- and 3-D testing. Operational aspects of AWTS's are discussed with regard to production type operation where adaptive wall adjustments need to be quick. Both 2- and 3-D data are presented to illustrate the quality of AWTS data over the transonic speed range. Adaptive wall technology is available for general use in 2-D testing, even in cryogenic wind tunnels. In 3-D testing, more refinement of the adaptive wall testing techniques is required before more widespread use can be planned.

  2. The experimental verification of wall movement influence coefficients for an adaptive walled test section

    NASA Technical Reports Server (NTRS)

    Neal, G.

    1988-01-01

    Flexible walled wind tunnels have for some time been used to reduce wall interference effects at the model. A necessary part of the 3-D wall adjustment strategy being developed for the Transonic Self-Streamlining Wind Tunnel (TSWT) of Southampton University is the use of influence coefficients. The influence of a wall bump on the centerline flow in TSWT has been calculated theoretically using a streamline curvature program. This report details the experimental verification of these influence coefficients and concludes that it is valid to use the theoretically determined values in 3-D model testing.

  3. Adaptive wall functions for moving walls using the k-φ turbulence model

    NASA Astrophysics Data System (ADS)

    Axerio-Cilies, John; Iaccarino, Gianluca

    2010-11-01

    An adaptive wall function for the k-φ model is derived for moving walls starting from a wall-resolved RANS computation of the flow over a moving flat plate with zero pressure gradient. The wall function is implemented via lookup tables for the turbulence quantities and the friction velocity uτ. The reference well-resolved, grid-converged RANS numerical solutions are obtained using the k-φ turbulence model with wall integration on very fine grids (y+ <1). Selecting a reference frame such that U∞>=0 yields three distinct velocity profile regimes: U∞>=0 < Uw, U∞>=Uw>=0, and Uw>U∞>=0. It is shown that adaptive wall functions are appropriate for all three velocity profile regimes as well as different Reynolds numbers when the near wall grid resolution is not sufficient (y+>1). For very fine grids (y+<1) this approach yields results consistent with the wall integration solution. Finally, the performance of the proposed adaptive wall functions is investigated for the complex flow around a rotating Formula 1 tire. The complexity of this flow arises from the impingement and jetting at the front of the tire, strong pressure gradients, and the large separated region behind the tire.

  4. Wall teichoic acids prevent antibody binding to epitopes within the cell wall of Staphylococcus aureus.

    PubMed

    Gautam, Samir; Kim, Taehan; Lester, Evan; Deep, Deeksha; Spiegel, David A

    2016-01-15

    Staphylococcus aureus is a Gram-positive bacterial pathogen that produces a range of infections including cellulitis, pneumonia, and septicemia. The principle mechanism in antistaphylococcal host defense is opsonization with antibodies and complement proteins, followed by phagocytic clearance. Here we use a previously developed technique for installing chemical epitopes in the peptidoglycan cell wall to show that surface glycopolymers known as wall teichoic acids conceal cell wall epitopes, preventing their recognition and opsonization by antibodies. Thus, our results reveal a previously unrecognized immunoevasive role for wall teichoic acids in S. aureus: repulsion of peptidoglycan-targeted antibodies.

  5. Moving Towards Domain Wall Devices in Ferroics

    NASA Astrophysics Data System (ADS)

    Gregg, Marty

    Domain walls in ferroelectric, ferroelastic and multiferroic oxides are distinct functional materials in their own right. They can be conducting, or even superconducting, when surrounding domains are insulating; they can demonstrate magnetism when the surrounding bulk is non-magnetic and they can contain ordered electrical dipoles when the matrix containing them is non-polar. Since domain walls can also be created, destroyed, and controllably moved from place to place, there is an amazing opportunity for us to design new forms of devices in which functionality is actively and dynamically deployed (now you see it; now you don't). This is the essence of the emerging field known as ``domain wall nanoelectronics''. In time, this arena of research could change the way we think of nanoscale functional devices, moving increasingly towards agile circuitry and neuromorphic device architectures. While the control of domain wall injection, movement and annihilation has been developed rather well in the nanomagnetics community (in race-track and domain wall logic research), similar research has not been widely performed in nanoscale ferroelectrics, ferroelastics and multiferroics. This talk will discuss progress that has been made to date and the way in which nanomagnetics research can be used as a source of inspiration. Site-specific domain wall injection and motion control in both proper and improper ferroelectrics using inhomogeneous electric and elastic fields, as well as dielectric patterning in uniaxial ferroelectrics, will be specifically considered. As will be shown, sufficient control has been developed to allow the creation of a diode for domain wall motion in ferroelectrics, for example. The author acknowledges support from the Engineering and Physical Sciences Research Council (EPSRC).

  6. Crystal Melting and Wall Crossing Phenomena

    NASA Astrophysics Data System (ADS)

    Yamazaki, Masahito

    2010-02-01

    This paper summarizes recent developments in the theory of Bogomol'nyi-Prasad-Sommerfield (BPS) state counting and the wall crossing phenomena, emphasizing in particular the role of the statistical mechanical model of crystal melting. This paper is divided into two parts, which are closely related to each other. In the first part, we discuss the statistical mechanical model of crystal melting counting BPS states. Each of the BPS state contributing to the BPS index is in one-to-one correspondence with a configuration of a molten crystal, and the statistical partition function of the melting crystal gives the BPS partition function. We also show that smooth geometry of the Calabi-Yau manifold emerges in the thermodynamic limit of the crystal. This suggests a remarkable interpretation that an atom in the crystal is a discretization of the classical geometry, giving an important clue as to the geometry at the Planck scale.In the second part we discuss the wall crossing phenomena. Wall crossing phenomena states that the BPS index depends on the value of the moduli of the Calabi-Yau manifold, and jumps along real codimension one subspaces in the moduli space. We show that by using type IIA/M-theory duality, we can provide a simple and an intuitive derivation of the wall crossing phenomena, furthermore clarifying the connection with the topological string theory. This derivation is consistent with another derivation from the wall crossing formula, motivated by multi-centered BPS extremal black holes. We also explain the representation of the wall crossing phenomena in terms of crystal melting, and the generalization of the counting problem and the wall crossing to the open BPS invariants.

  7. Crystal Melting and Wall Crossing Phenomena

    NASA Astrophysics Data System (ADS)

    Yamazaki, Masahito

    This paper summarizes recent developments in the theory of Bogomol'nyi-Prasad-Sommerfield (BPS) state counting and the wall crossing phenomena, emphasizing in particular the role of the statistical mechanical model of crystal melting. This paper is divided into two parts, which are closely related to each other. In the first part, we discuss the statistical mechanical model of crystal melting counting BPS states. Each of the BPS states contributing to the BPS index is in one-to-one correspondence with a configuration of a molten crystal, and the statistical partition function of the melting crystal gives the BPS partition function. We also show that smooth geometry of the Calabi-Yau manifold emerges in the thermodynamic limit of the crystal. This suggests a remarkable interpretation that an atom in the crystal is a discretization of the classical geometry, giving an important clue as such to the geometry at the Planck scale. In the second part, we discuss the wall crossing phenomena. Wall crossing phenomena states that the BPS index depends on the value of the moduli of the Calabi-Yau manifold, and jumps along real codimension one subspaces in the moduli space. We show that by using type IIA/M-theory duality, we can provide a simple and an intuitive derivation of the wall crossing phenomena, furthermore clarifying the connection with the topological string theory. This derivation is consistent with another derivation from the wall crossing formula, motivated by multicentered BPS extremal black holes. We also explain the representation of the wall crossing phenomena in terms of crystal melting, and the generalization of the counting problem and the wall crossing to the open BPS invariants.

  8. Structural domain walls in polar hexagonal manganites

    NASA Astrophysics Data System (ADS)

    Kumagai, Yu

    2014-03-01

    The domain structure in the multiferroic hexagonal manganites is currently intensely investigated, motivated by the observation of intriguing sixfold topological defects at their meeting points [Choi, T. et al,. Nature Mater. 9, 253 (2010).] and nanoscale electrical conductivity at the domain walls [Wu, W. et al., Phys. Rev. Lett. 108, 077203 (2012).; Meier, D. et al., Nature Mater. 11, 284 (2012).], as well as reports of coupling between ferroelectricity, magnetism and structural antiphase domains [Geng, Y. et al., Nano Lett. 12, 6055 (2012).]. The detailed structure of the domain walls, as well as the origin of such couplings, however, was previously not fully understood. In the present study, we have used first-principles density functional theory to calculate the structure and properties of the low-energy structural domain walls in the hexagonal manganites [Kumagai, Y. and Spaldin, N. A., Nature Commun. 4, 1540 (2013).]. We find that the lowest energy domain walls are atomically sharp, with {210}orientation, explaining the orientation of recently observed stripe domains and suggesting their topological protection [Chae, S. C. et al., Phys. Rev. Lett. 108, 167603 (2012).]. We also explain why ferroelectric domain walls are always simultaneously antiphase walls, propose a mechanism for ferroelectric switching through domain-wall motion, and suggest an atomistic structure for the cores of the sixfold topological defects. This work was supported by ETH Zurich, the European Research Council FP7 Advanced Grants program me (grant number 291151), the JSPS Postdoctoral Fellowships for Research Abroad, and the MEXT Elements Strategy Initiative to Form Core Research Center TIES.

  9. Further reduction of near-wall resolution for wall-modeled LES

    NASA Astrophysics Data System (ADS)

    Marques, Alexandre; Wang, Qiqi; Larsson, Johan; Laskowski, Gregory; Bose, Sanjeeb

    2016-11-01

    One of the greatest challenges to the use of Large Eddy Simulations (LES) in engineering applications is the large number of grid points required near walls. To mitigate this issue, LES is often coupled with a model of the flow close to the wall, known as wall model. One feature common to most wall models is that the first few (about 3) grid points must be located below the inviscid log-layer (y / δ <= 0 . 2), and the grid must have near isotropic resolution near the wall. Hence, wall-modeled LES may still require a large number of grid points, both in the wall-normal and span-wise directions. Because of these requirements, wall-modeled LES still is unfeasible in many applications. We present a new formulation of wall-modeled LES that is being developed to address this issue. In this formulation, LES is used to solve only for the features of the velocity field that can be adequately represented on the LES grid. The effects of the unresolved features are captured by imposing a balance of momentum integrated in the wall-normal direction. This integral momentum balance translates into a dynamic PDE defined on the walls, which is coupled to the LES equations. We discuss details of the new formulation and present results obtained in laminar and turbulent channel flows. This work was partially supported by the Center of Turbulence Research at Stanford University, and by the U.S. Department of Energy under Award Number DE-SC-0011089.

  10. Enhancement of a Sunspot Light Wall with External Disturbances

    NASA Astrophysics Data System (ADS)

    Yang, Shuhong; Zhang, Jun; Erdélyi, Robert

    2016-12-01

    Based on the Interface Region Imaging Spectrograph observations, we study the response of a solar sunspot light wall to external disturbances. A flare occurrence near the light wall caused material to erupt from the lower solar atmosphere into the corona. Some material falls back to the solar surface and hits the light bridge (i.e., the base of the light wall), then sudden brightenings appear at the wall base followed by the rise of wall top, leading to an increase of the wall height. Once the brightness of the wall base fades, the height of the light wall begins to decrease. Five hours later, another nearby flare takes place, and a bright channel is formed that extends from the flare toward the light bridge. Although no obvious material flow along the bright channel is found, some ejected material is conjectured to reach the light bridge. Subsequently, the wall base brightens and the wall height begins to increase again. Once more, when the brightness of the wall base decays, the wall top fluctuates to lower heights. We suggest, based on the observed cases, that the interaction of falling material and ejected flare material with the light wall results in the brightenings of wall base and causes the height of the light wall to increase. Our results reveal that the light wall can be not only powered by the linkage of p-mode from below the photosphere, but may also be enhanced by external disturbances, such as falling material.

  11. 17. DETAIL OF INTERIOR AND EXTERIOR WALL CONSTRUCTION, VIEW TOWARD ...

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

    17. DETAIL OF INTERIOR AND EXTERIOR WALL CONSTRUCTION, VIEW TOWARD NORTHEAST CORNER, THIRD BAY Showing insulated exterior wall at right; asphalt felt on interior separation wall at left; sill beam, stud, and concrete foundation detailing of interior wall. - U.S. Military Academy, Ice House, Mills Road at Howze Place, West Point, Orange County, NY

  12. 24. VIEW OF NORTHWEST WALL IN ROOM 209, RESTROOM. EXPOSED ...

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

    24. VIEW OF NORTHWEST WALL IN ROOM 209, RESTROOM. EXPOSED BEAM RUNS ALONG NORTHWEST WALL. 3X3 LITE WINDOW IS IN THE NORTHEAST WALL. FLOOR TREATMENT IS WOOD, WALLS ARE GYPSUM BOARD. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

  13. The Structure of Plant Cell Walls

    PubMed Central

    Wilder, Barry M.; Albersheim, Peter

    1973-01-01

    The molecular structure and chemical properties of the hemicellulose present in the isolated cell walls of suspension cultures of sycamore (Acer pseudoplatanus) cells has recently been described by Bauer et al. (Plant Physiol. 51: 174-187). The hemicellulose of the sycamore primary cell wall is a xyloglucan. This polymer functions as an important cross-link in the structure of the cell wall; the xyloglucan is hydrogen-bonded to cellulose and covalently attached to the pectic polymers. The present paper describes the structure of a xyloglucan present in the walls and in the extracellular medium of suspension-cultured Red Kidney bean (Phaseolus vulgaris) cells and compares the structure of the bean xyloglucan with the structure of the sycamore xyloglucan. Although some minor differences were found, the basic structure of the xyloglucans in the cell walls of these distantly related species is the same. The structure is based on a repeating heptasaccharide unit which consists of four residues of β-1, 4-linked glucose and three residues of terminal xylose linked to the 6 position of three of the glucosyl residues. PMID:16658434

  14. Identification of Novel Cell Wall Components

    SciTech Connect

    Michelle Momany

    2009-10-26

    Our DOE Biosciences-funded work focused on the fungal cell wall and morphogenesis. We are especially interested in how new cell wall material is targeted to appropriate areas for polar (asymmetric) growth. Polar growth is the only way that filamentous fungi explore the environment to find suitable substrates to degrade. Work funded by this grant has resulted in a total of twenty peer-reviewed publications. In work funded by this grant, we identified nine Aspergillus nidulans temperature-sensitive (ts) mutants that fail to send out a germ tube and show a swollen cell phenotype at restrictive temperature, the swo mutants. In other organisms, a swollen cell phenotype is often associated with misdirected growth or weakened cell walls. Our work shows that several of the A. nidulans swo mutants have defects in the establishment and maintenance of polarity. Cloning of several swo genes by complementation also showed that secondary modification of proteins seems is important in polarity. We also investigated cell wall biosynthesis and branching based on leads in literature from other organisms and found that branching and nuclear division are tied and that the cell wall reorganizes during development. In our most recent work we have focused on gene expression during the shift from isotropic to polar growth. Surprisingly we found that genes previously thought to be involved only in spore formation are important in early vegetative growth as well.

  15. Quantum properties of charged ferroelectric domain walls

    NASA Astrophysics Data System (ADS)

    Sturman, B.; Podivilov, E.; Stepanov, M.; Tagantsev, A.; Setter, N.

    2015-12-01

    We consider the properties of charged domain walls in ferroelectrics as a quantum problem. This includes determination of self-consistent attracting 1D potential for compensating charge carriers, the number and positions of discrete energy levels in this potential, dependencies on the ferroelectric characteristics, as well as the spatial structure and formation energy of the wall. Our description is based on the Hartree and Thomas-Fermi methods and Landau theory for the ferroelectric transitions. Changeover from a few to many quantum levels (with the electron binding energies ˜1 eV) is controlled by a single characteristic parameter. The quantum models well describe the core of the wall, whose width is typically ˜10 nm. Additionally, the walls possess pronounced long-range tails which are due to trap recharging. For the trap concentration Nt=(1017-1018) cm-3 , the tail length ℓ is of the μ m scale. On the distances much larger than ℓ the walls are electrically uncoupled from each other and the crystal faces.

  16. Modes of deformation of walled cells.

    PubMed

    Dumais, Jacques

    2013-11-01

    The bewildering morphological diversity found in cells is one of the starkest illustrations of life's ability to self-organize. Yet the morphogenetic mechanisms that produce the multifarious shapes of cells are still poorly understood. The shared similarities between the walled cells of prokaryotes, many protists, fungi, and plants make these groups particularly appealing to begin investigating how morphological diversity is generated at the cell level. In this review, I attempt a first classification of the different modes of surface deformation used by walled cells. Five modes of deformation were identified: inextensional bending, equi-area shear, elastic stretching, processive intussusception, and chemorheological growth. The two most restrictive modes-inextensional and equi-area deformations-are embodied in the exine of pollen grains and the wall-like pellicle of euglenoids, respectively. For these modes, it is possible to express the deformed geometry of the cell explicitly in terms of the undeformed geometry and other easily observable geometrical parameters. The greatest morphogenetic power is reached with the processive intussusception and chemorheological growth mechanisms that underlie the expansive growth of walled cells. A comparison of these two growth mechanisms suggests a possible way to tackle the complexity behind wall growth.

  17. Evaluation of the High-Heel Roof-to-Wall Connection with Extended OSB Wall Sheathing

    Treesearch

    Andrew DeRenzis; Vladimir Kochkin; Xiping Wang

    2013-01-01

    A recently completed testing project conducted to evaluate optimized structural roof-to-wall attachment solutions demonstrated the effectiveness of wood structural panels in restraining high-heel trusses against rotation. This study was designed to further evaluate the performance of OSB wall sheathing panels extended over the high-heel truss in resisting combined...

  18. The role of wall calcium in the extension of cell walls of soybean hypocotyls

    NASA Technical Reports Server (NTRS)

    Virk, S. S.; Cleland, R. E.

    1990-01-01

    Calcium crosslinks are load-bearing bonds in soybean (Glycine max (L.) Merr.) hypocotyl cell walls, but they are not the same load-bearing bonds that are broken during acid-mediated cell elongation. This conclusion is reached by studying the relationship between wall calcium, pH and the facilitated creep of frozen-thawed soybean hypocotyl sections. Supporting data include the following observations: 1) 2-[(2-bis-[carboxymethyl]amino-5-methylphenoxy)methyl]-6-methoxy-8-bis[car boxymethyl]aminoquinoline (Quin 2) and ethylene glycol-bis(2-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) caused only limited facilitated creep as compared with acid, despite removal of comparable or larger amounts of wall calcium; 2) the pH-response curves for calcium removal and acid-facilitated creep were different; 3) reversible acid-extension occurred even after removal of almost all wall calcium with Quin 2; and 4) growth of abraded sections did not involve a proportional loss of wall calcium. Removal of wall calcium, however, increased the capacity of the walls to undergo acid-facilitated creep. These data indicate that breakage of calcium crosslinks is not a major mechanism of cell-wall loosening in soybean hypocotyl tissues.

  19. 32. DETAIL OF WALL SHOWN IN SD231. BEHIND WALL FRAMING ...

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

    32. DETAIL OF WALL SHOWN IN SD-2-31. BEHIND WALL FRAMING IS SAMPLING ROOM WITH WOOD SAMPLING ELEVATOR. CRUSHED OXIDIZED ORE BIN ON LEFT (SOUTH). - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  20. Numerical study of laminar wall jet with transpiration and moving wall

    NASA Astrophysics Data System (ADS)

    Abedin, Md. Ariful; Raju, Md. Taj Uddin; Siraj, Md. Tanvir; Debnath, Amit

    2017-06-01

    Laminar wall jet is a unidirectional flow without any pressure gradient and is driven by its own momentum. This paper represents this phenomenon for two important cases-stationary wall without transpiration and moving wall with transpiration. Continuity and momentum equations have been developed for these two conditions. Similar to Glauerts theory, similarity transformation has been applied to find out the governing equation, a third order ordinary differential equation. Shooting method is applied to find out the proper boundary condition to solve the governing equation. Finally, an algorithm for 4th order Runge Kutta method has been augmented to find out the solution using MATLAB. As the jet moves forward in the case of a stationary wall without any transpiration, the maximum velocity, which is slightly greater than 0.4 m/s, occurs at a distance from the wall. The velocity curve for this case does not show any rapid change in the flow. But for the second case (moving wall with transpiration), the maximum velocity is obtained near the wall surface which is slightly greater than the wall velocity, 1.13 m/s. As the jet proceeds, due to suction, the velocity decreases rapidly. Again, the dominance of suction force forces the transverse velocity to achieve a lower value in the second case rather than in first case. The flow physics behind these scenarios is studied in detail in this work and is discussed for a range of operating conditions.

  1. Regulation of Cell Wall Biogenesis in Saccharomyces cerevisiae: The Cell Wall Integrity Signaling Pathway

    PubMed Central

    Levin, David E.

    2011-01-01

    The yeast cell wall is a strong, but elastic, structure that is essential not only for the maintenance of cell shape and integrity, but also for progression through the cell cycle. During growth and morphogenesis, and in response to environmental challenges, the cell wall is remodeled in a highly regulated and polarized manner, a process that is principally under the control of the cell wall integrity (CWI) signaling pathway. This pathway transmits wall stress signals from the cell surface to the Rho1 GTPase, which mobilizes a physiologic response through a variety of effectors. Activation of CWI signaling regulates the production of various carbohydrate polymers of the cell wall, as well as their polarized delivery to the site of cell wall remodeling. This review article centers on CWI signaling in Saccharomyces cerevisiae through the cell cycle and in response to cell wall stress. The interface of this signaling pathway with other pathways that contribute to the maintenance of cell wall integrity is also discussed. PMID:22174182

  2. The role of wall calcium in the extension of cell walls of soybean hypocotyls

    NASA Technical Reports Server (NTRS)

    Virk, S. S.; Cleland, R. E.

    1990-01-01

    Calcium crosslinks are load-bearing bonds in soybean (Glycine max (L.) Merr.) hypocotyl cell walls, but they are not the same load-bearing bonds that are broken during acid-mediated cell elongation. This conclusion is reached by studying the relationship between wall calcium, pH and the facilitated creep of frozen-thawed soybean hypocotyl sections. Supporting data include the following observations: 1) 2-[(2-bis-[carboxymethyl]amino-5-methylphenoxy)methyl]-6-methoxy-8-bis[car boxymethyl]aminoquinoline (Quin 2) and ethylene glycol-bis(2-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) caused only limited facilitated creep as compared with acid, despite removal of comparable or larger amounts of wall calcium; 2) the pH-response curves for calcium removal and acid-facilitated creep were different; 3) reversible acid-extension occurred even after removal of almost all wall calcium with Quin 2; and 4) growth of abraded sections did not involve a proportional loss of wall calcium. Removal of wall calcium, however, increased the capacity of the walls to undergo acid-facilitated creep. These data indicate that breakage of calcium crosslinks is not a major mechanism of cell-wall loosening in soybean hypocotyl tissues.

  3. Brain springs: fast physics for large crowds in WAll*E.

    PubMed

    Kanyuk, Paul

    2009-01-01

    A major challenge of making WALL*E was creating believable physics for human and robot crowds. To do this, Pixar technical directors combined a custom spring-physics system in the Massive software platform with traditional simulation methods. The performance was fast enough to scale for large crowds and maintain interactivity for previews.

  4. Enhanced cold wall CVD reactor growth of horizontally aligned single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Mu, Wei; Kwak, Eun-Hye; Chen, Bingan; Huang, Shirong; Edwards, Michael; Fu, Yifeng; Jeppson, Kjell; Teo, Kenneth; Jeong, Goo-Hwan; Liu, Johan

    2016-05-01

    HASynthesis of horizontally-aligned single-walled carbon nanotubes (HA-SWCNTs) by chemical vapor deposition (CVD) directly on quartz seems very promising for the fabrication of future nanoelectronic devices. In comparison to hot-wall CVD, synthesis of HA-SWCNTs in a cold-wall CVD chamber not only means shorter heating, cooling and growth periods, but also prevents contamination of the chamber. However, since most synthesis of HA-SWCNTs is performed in hot-wall reactors, adapting this well-established process to a cold-wall chamber becomes extremely crucial. Here, in order to transfer the CVD growth technology from a hot-wall to a cold-wall chamber, a systematic investigation has been conducted to determine the influence of process parameters on the HA-SWCNT's growth. For two reasons, the cold-wall CVD chamber was upgraded with a top heater to complement the bottom substrate heater; the first reason to maintain a more uniform temperature profile during HA-SWCNTs growth, and the second reason to preheat the precursor gas flow before projecting it onto the catalyst. Our results show that the addition of a top heater had a significant effect on the synthesis. Characterization of the CNTs shows that the average density of HA-SWCNTs is around 1 - 2 tubes/ μm with high growth quality as shown by Raman analysis. [Figure not available: see fulltext.

  5. Stability of resistive wall modes with plasma rotation and thick wall in ITER scenario

    NASA Astrophysics Data System (ADS)

    Zheng, L. J.; Kotschenreuther, M.; Chu, M.; Chance, M.; Turnbull, A.

    2004-11-01

    The rotation effect on resistive wall modes (RWMs) is examined for realistically shaped, high-beta tokamak equilibria, including reactor relevant cases with low mach number M and realistic thick walls. For low M, Stabilization of RWMs arises from unusually thin inertial layers. The investigation employs the newly developed adaptive eigenvalue code (AEGIS: Adaptive EiGenfunction Independent Solution), which describes both low and high n modes and is in good agreement with GATO in the benchmark studies. AEGIS is unique in using adaptive methods to resolve such inertial layers with low mach number rotation. This feature is even more desirable for transport barrier cases. Additionally, ITER and reactors have thick conducting walls ( ˜.5-1 m) which are not well modeled as a thin shell. Such thick walls are considered here, including semi-analytical approximations to account for the toroidally segmented nature of real walls.

  6. Radial Corrugations of Multi-Walled Carbon Nanotubes Driven by Inter-Wall Nonbonding Interactions.

    PubMed

    Huang, Xu; Liang, Wentao; Zhang, Sulin

    2011-12-01

    We perform large-scale quasi-continuum simulations to determine the stable cross-sectional configurations of free-standing multi-walled carbon nanotubes (MWCNTs). We show that at an inter-wall spacing larger than the equilibrium distance set by the inter-wall van der Waals (vdW) interactions, the initial circular cross-sections of the MWCNTs are transformed into symmetric polygonal shapes or asymmetric water-drop-like shapes. Our simulations also show that removing several innermost walls causes even more drastic cross-sectional polygonization of the MWCNTs. The predicted cross-sectional configurations agree with prior experimental observations. We attribute the radial corrugations to the compressive stresses induced by the excessive inter-wall vdW energy release of the MWCNTs. The stable cross-sectional configurations provide fundamental guidance to the design of single MWCNT-based devices and shed lights on the mechanical control of electrical properties.

  7. Comparison of a two-dimensional adaptive-wall technique with analytical wall interference correction techniques

    NASA Technical Reports Server (NTRS)

    Mineck, Raymond E.

    1992-01-01

    A two dimensional airfoil model was tested in the adaptive wall test section of the NASA Langley 0.3 meter Transonic Cryogenic Tunnel (TCT) and in the ventilated test section of the National Aeronautical Establishment Two Dimensional High Reynold Number Facility (HRNF). The primary goal of the tests was to compare different techniques (adaptive test section walls and classical, analytical corrections) to account for wall interference. Tests were conducted over a Mach number range from 0.3 to 0.8 at chord Reynolds numbers of 10 x 10(exp 6), 15 x 10(exp 6), and 20 x 10(exp 6). The angle of attack was varied from about 12 degrees up to stall. Movement of the top and bottom test section walls was used to account for the wall interference in the HRNF tests. The test results are in good agreement.

  8. Turbine airfoil with a compliant outer wall

    DOEpatents

    Campbell, Christian X [Oviedo, FL; Morrison, Jay A [Oviedo, FL

    2012-04-03

    A turbine airfoil usable in a turbine engine with a cooling system and a compliant dual wall configuration configured to enable thermal expansion between inner and outer layers while eliminating stress formation in the outer layer is disclosed. The compliant dual wall configuration may be formed a dual wall formed from inner and outer layers separated by a support structure. The outer layer may be a compliant layer configured such that the outer layer may thermally expand and thereby reduce the stress within the outer layer. The outer layer may be formed from a nonplanar surface configured to thermally expand. In another embodiment, the outer layer may be planar and include a plurality of slots enabling unrestricted thermal expansion in a direction aligned with the outer layer.

  9. Sequential buckling of an elastic wall

    NASA Astrophysics Data System (ADS)

    Bico, Jose; Bense, Hadrien; Keiser, Ludovic; Roman, Benoit; Melo, Francisco; Abkarian, Manouk

    A beam under quasistatic compression classically buckles beyond a critical threshold. In the case of a free beam, the lowest buckling mode is selected. We investigate the case of a long ``wall'' grounded of a compliant base and compressed in the axial compression. In the case of a wall of slender rectangular cross section, the selected buckling mode adopts a nearly fixed wavelength proportional to the height of the wall. Higher compressive loads only increase the amplitude of the buckle. However if the cross section has a sharp shape (such as an Eiffel tower profile), we observe successive buckling modes of increasing wavelength. We interpret this unusual evolution in terms of scaling arguments. At small scales, this variable periodicity might be used to develop tunable optical devices. We thank ECOS C12E07, CNRS-CONICYT, and Fondecyt Grant No. N1130922 for partially funding this work.

  10. Prephonatory chest wall posturing in stutterers.

    PubMed

    Baken, R J; McManus, D A; Cavallo, S A

    1983-09-01

    The possibility that prephonatory chest wall posturing is abnormal in stutterers was explored by observing rib cage and abdominal hemicircumference changes during the interval between the presentation of a stimulus and the production of/alpha/by a group of stutterers (N = 5). It was found that the patterns of chest wall adjustment for phonation were qualitatively identical in the stutterers and in a comparable group of normal men studied previously. There was, however, a significant difference in the way in which lung volume changed during the execution of the chest wall adjustment. This was considered to be indicative of delayed glottal closure among the stutterers rather than representative of a primary ventilatory disturbance.

  11. Dispersive Stiffness of Dzyaloshinskii Domain Walls

    NASA Astrophysics Data System (ADS)

    Pellegren, J. P.; Lau, D.; Sokalski, V.

    2017-07-01

    It is well documented that subjecting perpendicular magnetic films that exhibit the interfacial Dzyaloshinskii-Moriya interaction to an in-plane magnetic field results in a domain wall (DW) energy σ , which is highly anisotropic with respect to the orientation of the DW in the film plane Θ . We demonstrate that this anisotropy has a profound impact on the elastic response of the DW as characterized by the surface stiffness σ ˜ (Θ )=σ (Θ )+σ''(Θ ) and evaluate its dependence on the length scale of deformation. The influence of stiffness on DW mobility in the creep regime is assessed, with analytic and numerical calculations showing trends in σ ˜ that better represent experimental measurements of domain wall velocity in magnetic thin films compared to σ alone. Our treatment provides experimental support for theoretical models of the mobility of anisotropic elastic manifolds and makes progress toward a more complete understanding of magnetic domain wall creep.

  12. Wall thickness measuring method and apparatus

    DOEpatents

    Salzer, Leander J.; Bergren, Donald A.

    1989-01-01

    An apparatus for measuring the wall thickness of a nonmagnetic article having a housing supporting a magnet and a contiguous supporting surface. The tubular article and the housing are releasably secured to the supporting surface and a support member of an optical comparator, respectively. To determine the wall thickness of the article at a selected point, a magnetically responsive ball is positioned within the tubular article over said point and retained therein by means of a magnetic field produced by the magnet. Thereafter, an optical comparator is employed to project a magnified image of the ball on a screen and the wall thickness at the selected point is calculated by using a ball surface measurement taken with the comparator in conjunction with a previously determined base line measurement.

  13. Analysis of a dusty wall jet

    NASA Technical Reports Server (NTRS)

    Lim, Hock-Bin; Roberts, Leonard

    1991-01-01

    An analysis is given for the entrainment of dust into a turbulent radial wall jet. Equations are solved based on incompressible flow of a radial wall jet into which dust is entrained from the wall and transported by turbulent diffusion and convection throughout the flow. It is shown that the resulting concentration of dust particles in the flow depends on the difference between the applied shear stress at the surface and the maximum level of shear stress that the surface can withstand (varies as rho(sub d)a(sub g)D) i.e., the pressure due to the weight of a single layer of dust. The analysis is expected to have application to the downflow that results from helicopter and VTOL aircraft.

  14. [Chest wall mesenchymal hamartoma: a case report].

    PubMed

    Morales, Olga Lucía; Valencia, María de la Luz; Gómez, Carolina; Pérez, María del Pilar; Sanín, Emilio; Vásquez, Luz Marina

    2010-01-01

    Chest wall mesenchymal hamartoma is an extremely rare benign tumor. Approximately 80 cases have been reported in the literature. Most tumors are manifested at birth with a painless palpable mass of the chest wall, usually unilateral. Respiratory symptoms result from extrinsic compression of the pulmonary parenchyma, and the severity of the symptoms will depend on the size and location of the lesion. Imaging features are characteristic, but definitive diagnosis is histological. Herein, a case is described of a four month old infant with diagnosis of chest wall mesenchymal hamartoma, manifested at birth. Different treatment options are described, including expectations from tumor management, the possibility of spontaneous regression, and the morbidity associated with the surgical option.

  15. Bubble Impact with a Solid Wall

    NASA Astrophysics Data System (ADS)

    Garg, Vishrut; Thete, Sumeet; Basaran, Osman

    2016-11-01

    In diverse natural and industrial processes, and in particular in process equipment widely used in oil and gas production, bubbles and drops that are immersed in a continuous liquid phase frequently collide with solid walls. In this talk, the impact with a solid wall of a gas bubble that is surrounded by a liquid that is either a Newtonian or a non-Newtonian fluid is analyzed by numerical simulation. Special attention is paid to the thin film that forms between the approaching bubble and the solid wall. Flow regimes that arise as the film thickness decreases are scrutinized and rationalized by comparison of the computational predictions to well-known and new analytical results from lubrication theory based thin film literature. Finally, flow transitions that occur as the lubrication theory breaks down and inertia becomes significant are investigated.

  16. Heat Load on the NCSX First Wall

    NASA Astrophysics Data System (ADS)

    Kaiser, T. B.; Monticello, D. N.; Hill, D. N.; Umansky, M. V.

    2003-10-01

    We have used magnetic field data generated by the PIES 3D MHD equilibrium code(M50 coil set) and a new vacuum field code(Michael Drevlak Max Planck Institute for Plasma Physics, Greifswald, Germany, private communication), together with the latest numerical model of the first wall (Art Brooks, PPPL, private communication) to compute wall heat loading in the National Compact Stellarator Experiment (NCSX) as a function of position. Field lines originating just outside the last closed magnetic surface are followed until they intersect the wall by integrating the field-line equations of motion in cylindrical coordinates using the LSODE integrator. Magnetic field values are interpolated with arbitrary-order splines. The local (nonuniform) heat flux is estimated from the density and incidence angle of escaping field lines.

  17. Anomalous feedback and negative domain wall resistance

    NASA Astrophysics Data System (ADS)

    Cheng, Ran; Zhu, Jian-Gang; Xiao, Di

    2016-11-01

    Magnetic induction can be regarded as a negative feedback effect, where the motive-force opposes the change of magnetic flux that generates the motive-force. In artificial electromagnetics emerging from spintronics, however, this is not necessarily the case. By studying the current-induced domain wall dynamics in a cylindrical nanowire, we show that the spin motive-force exerting on electrons can either oppose or support the applied current that drives the domain wall. The switching into the anomalous feedback regime occurs when the strength of the dissipative torque β is about twice the value of the Gilbert damping constant α. The anomalous feedback manifests as a negative domain wall resistance, which has an analogy with the water turbine.

  18. INTEGRATED ENERGY EFFICIENT WINDOW-WALL SYSTEMS

    SciTech Connect

    Michael Arney, Ph.D.

    2002-12-31

    The building industry faces the challenge of reducing energy use while simultaneously improving construction methods and marketability. This paper describes the first phase of a project to address these concerns by designing an Integrated Window Wall System (IWWS) that can be commercialized. This work builds on previous research conducted during the 1990's by Lawrence Berkeley national Laboratories (LBNL). During this phase, the objective was to identify appropriate technologies, problems and issues and develop a number of design concepts. Four design concepts were developed into prototypes and preliminary energy analyses were conducted Three of these concepts (the foam wall, steel wall, and stiffened plate designs) showed particular potential for meeting the project objectives and will be continued into a second phase where one or two of the systems will be brought closer to commercialization.

  19. Biphasic synovial sarcoma of the abdominal wall.

    PubMed

    Vera, Jesús; García, María-Dolores; Marigil, Miguel; Abascal, Manuel; Lopez, Jose-Ignacio; Ligorred, Luis

    2006-09-01

    Synovial sarcoma arising in the abdominal wall is a rare tumor. We report a case of a 38-year-old man who complained of abdominal pain. Physical examination revealed a firm mobile mass, 25 cm in diameter, in the left lower abdominal wall. The tumor was first thought to be a sarcoma arising from the omentum or mesentery. During surgery, a large tumor was found attached to the inner surface of the abdominal wall and compressing the gastrointestinal tract. On microscopic examination the tumor corresponded to a biphasic synovial sarcoma immunoreactive for cytokeratins (AE1/AE3, 7 and 19), epithelial membrane antigen and carcinoembryonic antigen in the epithelial tumor cells, for E-cadherin especially in their glandular structure, vimentin, CD99, and CD56 in the spindle cell component and for bcl-2 protein. The tumor recurred at the same site, and clinical course progressed to death 3 months after the initial diagnosis.

  20. Tunable resistivity of individual magnetic domain walls.

    PubMed

    Franken, J H; Hoeijmakers, M; Swagten, H J M; Koopmans, B

    2012-01-20

    Despite the relevance of current-induced magnetic domain wall (DW) motion for new spintronics applications, the exact details of the current-domain wall interaction are not yet understood. A property intimately related to this interaction is the intrinsic DW resistivity. Here, we investigate experimentally how the resistivity inside a DW depends on the wall width Δ, which is tuned using focused ion beam irradiation of Pt/Co/Pt strips. We observe the nucleation of individual DWs with Kerr microscopy, and measure resistance changes in real time. A 1/Δ(2) dependence of DW resistivity is found, compatible with Levy-Zhang theory. Also quantitative agreement with theory is found by taking full account of the current flowing through each individual layer inside the multilayer stack.

  1. First Wall, Blanket, Shield Engineering Technology Program

    SciTech Connect

    Nygren, R.E.

    1982-01-01

    The First Wall/Blanket/Shield Engineering Technology Program sponsored by the Office of Fusion Energy of DOE has the overall objective of providing engineering data that will define performance parameters for nuclear systems in advanced fusion reactors. The program comprises testing and the development of computational tools in four areas: (1) thermomechanical and thermal-hydraulic performance of first-wall component facsimiles with emphasis on surface heat loads; (2) thermomechanical and thermal-hydraulic performance of blanket and shield component facsimiles with emphasis on bulk heating; (3) electromagnetic effects in first wall, blanket, and shield component facsimiles with emphasis on transient field penetration and eddy-current effects; (4) assembly, maintenance and repair with emphasis on remote-handling techniques. This paper will focus on elements 2 and 4 above and, in keeping with the conference participation from both fusion and fission programs, will emphasize potential interfaces between fusion technology and experience in the fission industry.

  2. Translational Response of Toe-Restrained Retaining Walls to Earthquake Ground Motions Using CorpsWallSlip (CWSlip)

    DTIC Science & Technology

    2007-06-01

    invert spillway slab (not shown). The translation of the structural wedge is assumed to occur during earthquake shaking. A drop down box entitled...e.g., navigation walls retaining earth, spillway chute walls, spill- way discharge channel walls, approach channel walls to outlet works structures...1.5 Axial load capacity of spillway invert slabs..................................................................... 27 1.6 Background and research

  3. 40 CFR 721.10277 - Single-walled and multi-walled carbon nanotubes (generic) (P-10-40).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... chemical substance identified generically as single-walled and multi-walled carbon nanotubes (PMN P-10-40... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Single-walled and multi-walled carbon nanotubes (generic) (P-10-40). 721.10277 Section 721.10277 Protection of Environment ENVIRONMENTAL...

  4. Wood Pulp Digetster Wall Corrosion Investigation

    SciTech Connect

    Giles, GE

    2003-09-18

    The modeling of the flow in a wood pulp digester is but one component of the investigation of the corrosion of digesters. This report describes the development of a Near-Wall-Model (NWM) that is intended to couple with a CFD model that determines the flow, heat, and chemical species transport and reaction within the bulk flow of a digester. Lubrication theory approximations were chosen from which to develop a model that could determine the flow conditions within a thin layer near the vessel wall using information from the interior conditions provided by a CFD calculation of the complete digester. The other conditions will be determined by coupled solutions of the wood chip, heat, and chemical species transport and chemical reactions. The NWM was to couple with a digester performance code in an iterative fashion to provide more detailed information about the conditions within the NW region. Process Simulations, Ltd (PSL) is developing the digester performance code. This more detailed (and perhaps more accurate) information from the NWM was to provide an estimate of the conditions that could aggravate the corrosion at the wall. It is intended that this combined tool (NWM-PSL) could be used to understand conditions at/near the wall in order to develop methods to reduce the corrosion. However, development and testing of the NWM flow model took longer than anticipated and the other developments (energy and species transport, chemical reactions and linking with the PSL code) were not completed. The development and testing of the NWM are described in this report. In addition, the investigation of the potential effects of a clear layer (layer reduced in concentration of wood chips) near the wall is reported in Appendix D. The existence of a clear layer was found to enhance the flow near the wall.

  5. Recording Rapidly Changing Cylinder-wall Temperatures

    NASA Technical Reports Server (NTRS)

    Meier, Adolph

    1942-01-01

    The present report deals with the design and testing of a measuring plug suggested by H. Pfriem for recording quasi-stationary cylinder wall temperatures. The new device is a resistance thermometer, the temperature-susceptible part of which consists of a gold coating applied by evaporation under high vacuum and electrolytically strengthened. After overcoming initial difficulties, calibration of plugs up to and beyond 400 degrees C was possible. The measurements were made on high-speed internal combustion engines. The increasing effect of carbon deposit at the wall surface with increasing operating period is indicated by means of charts.

  6. Scaling properties of multitension domain wall networks

    NASA Astrophysics Data System (ADS)

    Oliveira, M. F.; Martins, C. J. A. P.

    2015-02-01

    We study the asymptotic scaling properties of domain wall networks with three different tensions in various cosmological epochs. We discuss the conditions under which a scale-invariant evolution of the network (which is well established for simpler walls) still applies and also consider the limiting case where defects are locally planar and the curvature is concentrated in the junctions. We present detailed quantitative predictions for scaling densities in various contexts, which should be testable by means of future high-resolution numerical simulations.

  7. Standing gravitational waves from domain walls

    SciTech Connect

    Gogberashvili, Merab; Myrzakul, Shynaray; Singleton, Douglas

    2009-07-15

    We construct a plane symmetric, standing gravitational wave for a domain wall plus a massless scalar field. The scalar field can be associated with a fluid which has the properties of 'stiff' matter, i.e., matter in which the speed of sound equals the speed of light. Although domain walls are observationally ruled out in the present era, the solution has interesting features which might shed light on the character of exact nonlinear wave solutions to Einstein's equations. Additionally this solution may act as a template for higher dimensional 'brane-world' model standing waves.

  8. Models for Gapped Boundaries and Domain Walls

    NASA Astrophysics Data System (ADS)

    Kitaev, Alexei; Kong, Liang

    2012-07-01

    We define a class of lattice models for two-dimensional topological phases with boundary such that both the bulk and the boundary excitations are gapped. The bulk part is constructed using a unitary tensor category {C} as in the Levin-Wen model, whereas the boundary is associated with a module category over {C} . We also consider domain walls (or defect lines) between different bulk phases. A domain wall is transparent to bulk excitations if the corresponding unitary tensor categories are Morita equivalent. Defects of higher codimension will also be studied. In summary, we give a dictionary between physical ingredients of lattice models and tensor-categorical notions.

  9. Enhancement of wall jet transport properties

    DOEpatents

    Claunch, S.D.; Farrington, R.B.

    1997-02-04

    By enhancing the natural instabilities in the boundary layer and in the free shear layer of a wall jet, the boundary is minimized thereby increasing the transport of heat and mass. Enhancing the natural instabilities is accomplished by pulsing the flow of air that creates the wall jet. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct. 17 figs.

  10. Enhancement of wall jet transport properties

    DOEpatents

    Claunch, Scott D.; Farrington, Robert B.

    1997-01-01

    By enhancing the natural instabilities in the boundary layer and in the free shear layer of a wall jet, the boundary is minimized thereby increasing the transport of heat and mass. Enhancing the natural instabilities is accomplished by pulsing the flow of air that creates the wall jet. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct.

  11. Wall reflection of a viscous vortex ring

    NASA Technical Reports Server (NTRS)

    Sa, J. Y.; Chang, K. S.; Liu, C. H.

    1986-01-01

    The behavior of a viscous axisymmetric vortex ring being reflected from a wall is investigated. The incompressible Navier-Stokes equations formulated in terms of the vorticity function and vector potential are numerically integrated by implicit finite difference methods. To specify the vector potential at a far boundary from the wall, the existing integral method used so far only for an unbounded domain is modified by a kind of image method. The trajectory of the vortex ring calcualted as a result closely resembles that observable from the experiment.

  12. Video System For Inspecting Walls Of Cavities

    NASA Technical Reports Server (NTRS)

    Gilbert, John A.; Matthys, Donald R.

    1996-01-01

    Endoscopic video-imaging system generates panoramic image of part of wall of cavity surrounding tip of probe inserted in cavity. Not necessary to rotate probe to obtain panoramic image. If simple inspection without measurement required, device called "cylindrical light ring" mounted on probe to illuminate scene. Different illumination device used when required to measure distance of wall of cavity from cylindrical axis of probe. System used, for example, to inspect inner surface of tube, passage, or manifold located deep within engine or other complex structure.

  13. Autolysis and extension of isolated walls from growing cucumber hypocotyls

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.; Durachko, D. M.

    1994-01-01

    Walls isolated from cucumber hypocotyls retain autolytic activities and the ability to extend when placed under the appropriate conditions. To test whether autolysis and extension are related, we treated the walls in various ways to enhance or inhibit long-term wall extension ('creep') and measured autolysis as release of various saccharides from the wall. Except for some non-specific inhibitors of enzymatic activity, we found no correlation between wall extension and wall autolysis. Most notably, autolysis and extension differed strongly in their pH dependence. We also found that exogenous cellulases and pectinases enhanced extension in native walls, but when applied to walls previously inactivated with heat or protease these enzymes caused breakage without sustained extension. In contrast, pretreatment of walls with pectinase or cellulase, followed by boiling in methanol to inactivate the enzymes, resulted in walls with much stronger expansin-mediated extension responses. Crude protein preparations from the digestive tracts of snails enhanced extension of both native and inactivated walls, and these preparations contained expansin-like proteins (assessed by Western blotting). Our results indicate that the extension of isolated cucumber walls does not depend directly on the activity of endogenous wall-bound autolytic enzymes. The results with exogenous enzymes suggest that the hydrolysis of matrix polysaccharides may not induce wall creep by itself, but may act synergistically with expansins to enhance wall extension.

  14. Autolysis and extension of isolated walls from growing cucumber hypocotyls

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.; Durachko, D. M.

    1994-01-01

    Walls isolated from cucumber hypocotyls retain autolytic activities and the ability to extend when placed under the appropriate conditions. To test whether autolysis and extension are related, we treated the walls in various ways to enhance or inhibit long-term wall extension ('creep') and measured autolysis as release of various saccharides from the wall. Except for some non-specific inhibitors of enzymatic activity, we found no correlation between wall extension and wall autolysis. Most notably, autolysis and extension differed strongly in their pH dependence. We also found that exogenous cellulases and pectinases enhanced extension in native walls, but when applied to walls previously inactivated with heat or protease these enzymes caused breakage without sustained extension. In contrast, pretreatment of walls with pectinase or cellulase, followed by boiling in methanol to inactivate the enzymes, resulted in walls with much stronger expansin-mediated extension responses. Crude protein preparations from the digestive tracts of snails enhanced extension of both native and inactivated walls, and these preparations contained expansin-like proteins (assessed by Western blotting). Our results indicate that the extension of isolated cucumber walls does not depend directly on the activity of endogenous wall-bound autolytic enzymes. The results with exogenous enzymes suggest that the hydrolysis of matrix polysaccharides may not induce wall creep by itself, but may act synergistically with expansins to enhance wall extension.

  15. Stabilization of the Resistive Wall Mode and Error Field Reduction by a Rotating Conducting Wall

    NASA Astrophysics Data System (ADS)

    Paz-Soldan, Carlos

    2011-10-01

    The hypothesis that the Resistive Wall Mode (RWM) can be stabilized by high-speed differentially-rotating conducting walls is tested in a linear device. This geometry allows the use of cylindrical solid metal walls, whereas a torus would require a flowing liquid metal. Experiments over the past year have for the first time explored RWM stability with a rotating copper wall capable of achieving speeds (rΩw) of up to 280 km/h, equivalent to a magnetic Reynolds number (Rm) of 5. The main results are: 1) Wall rotation increases the stability window of the RWM, allowing ~ 25% more plasma current (Ip) at Rm = 5 while maintaining MHD stability. 2) Error field reduction below a critical value allows the observation of initial mode rotation, followed by braking, wall-locking, and subsequent faster growth. 3) Locking is found to depend on the direction of wall rotation (Ω̂w) with respect to the intrinsic plasma rotation, with locking to both the static wall (vacuum vessel) and rotating wall observed. Additionally, indirect effects on RWM stability are observed via the effect of wall rotation on device error fields. Wall rotation shields locking error fields, which reduces the braking torque and inhibits mode-locking. The linear superposition of error fields from guide field (Bz) solenoid misalignments and current-carrying leads is also shown to break symmetry in Ω̂w , with one direction causing stronger error fields and earlier locking irrespective of plasma flow. Vacuum field measurements further show that rotation decreases the error field penetration time and advects the field to a different orientation, as predicted by theory. Experiments are conducted on the Rotating Wall Machine, a 1.2 m long and 16 cm diameter screw-pinch with Bz ~ 500 G, where hollow-cathode injectors are biased to source up to 7 kA of Ip, exciting current-driven RWMs. MHD activity is measured through 120 edge Br, Bθ, Bz probes as well as internal Bdot, Langmuir and Mach probes. RWM

  16. An experimental study of near wall flow parameters in the blade end-wall corner region

    NASA Technical Reports Server (NTRS)

    Bhargava, Rakesh K.; Raj, Rishi S.

    1989-01-01

    The near wall flow parameters in the blade end-wall corner region is investigated. The blade end-wall corner region was simulated by mounting an airfoil section (NACA 65-015 base profile) symmetric blades on both sides of the flat plate with semi-circular leading edge. The initial 7 cm from the leading edge of the flat plate was roughened by gluing No. 4 floor sanding paper to artificially increase the boundary layer thickness on the flat plate. The initial flow conditions of the boundary layer upstream of the corner region are expected to dictate the behavior of flow inside the corner region. Therefore, an experimental investigation was extended to study the combined effect of initial roughness and increased level of free stream turbulence on the development of a 2-D turbulent boundary layer in the absence of the blade. The measurement techniques employed in the present investigation included, the conventional pitot and pitot-static probes, wall taps, the Preston tube, piezoresistive transducer and the normal sensor hot-wire probe. The pitot and pitot-static probes were used to obtain mean velocity profile measurements within the boundary layer. The measurements of mean surface static pressure were obtained with the surface static tube and the conventional wall tap method. The wall shear vector measurements were made with a specially constructed Preston tube. The flush mounted piezoresistive type pressure transducer were employed to measure the wall pressure fluctuation field. The velocity fluctuation measurements, used in obtaining the wall pressure-velocity correlation data, were made with normal single sensor hot-wire probe. At different streamwise stations, in the blade end-wall corner region, the mean values of surface static pressure varied more on the end-wall surface in the corner region were mainly caused by the changes in the curvature of the streamlines. The magnitude of the wall shear stress in the blade end-wall corner region increased significantly

  17. Shear localization and effective wall friction in a wall bounded granular flow

    NASA Astrophysics Data System (ADS)

    Artoni, Riccardo; Richard, Patrick

    2017-06-01

    In this work, granular flow rheology is investigated by means of discrete numerical simulations of a torsional, cylindrical shear cell. Firstly, we focus on azimuthal velocity profiles and study the effect of (i) the confining pressure, (ii) the particle-wall friction coefficient, (iii) the rotating velocity of the bottom wall and (iv) the cell diameter. For small cell diameters, azimuthal velocity profiles are nearly auto-similar, i.e. they are almost linear with the radial coordinate. Different strain localization regimes are observed : shear can be localized at the bottom, at the top of the shear cell, or it can be even quite distributed. This behavior originates from the competition between dissipation at the sidewalls and dissipation in the bulk of the system. Then we study the effective friction at the cylindrical wall, and point out the strong link between wall friction, slip and fluctuations of forces and velocities. Even if the system is globally below the sliding threshold, force fluctuations trigger slip events, leading to a nonzero wall slip velocity and an effective wall friction coefficient different from the particle-wall one. A scaling law was found linking slip velocity, granular temperature in the main flow direction and effective friction. Our results suggest that fluctuations are an important ingredient for theories aiming to capture the interface rheology of granular materials.

  18. Cell wall proteomic of Brachypodium distachyon grains: A focus on cell wall remodeling proteins.

    PubMed

    Francin-Allami, Mathilde; Merah, Kahina; Albenne, Cécile; Rogniaux, Hélène; Pavlovic, Marija; Lollier, Virginie; Sibout, Richard; Guillon, Fabienne; Jamet, Elisabeth; Larré, Colette

    2015-07-01

    Cell walls play key roles during plant development. Following their deposition into the cell wall, polysaccharides are continually remodeled according to the growth stage and stress environment to accommodate cell growth and differentiation. To date, little is known concerning the enzymes involved in cell wall remodeling, especially in gramineous and particularly in the grain during development. Here, we investigated the cell wall proteome of the grain of Brachypodium distachyon. This plant is a suitable model for temperate cereal crops. Among the 601 proteins identified, 299 were predicted to be secreted. These proteins were distributed into eight functional classes; the class of proteins that act on carbohydrates was the most highly represented. Among these proteins, numerous glycoside hydrolases were found. Expansins and peroxidases, which are assumed to be involved in cell wall polysaccharide remodeling, were also identified. Approximately half of the proteins identified in this study were newly discovered in grain and were not identified in the previous proteome analysis conducted using the culms and leaves of B. distachyon. Therefore, the data obtained from all organs of B. distachyon infer a global cell wall proteome consisting of 460 proteins. At present, this is the most extensive cell wall proteome of a monocot species.

  19. Stepped chute training wall height requirements

    USDA-ARS?s Scientific Manuscript database

    Stepped chutes are commonly used for overtopping protection for embankment dams. Aerated flow is commonly associated with stepped chutes if the chute has sufficient length. The aeration and turbulence of the flow can create a significant amount of splash over the training wall if not appropriately...

  20. 14 CFR 121.245 - Fire walls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fire walls. 121.245 Section 121.245 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS..., auxiliary power unit, fuel-burning heater, or other item of combustion equipment that is intended for...

  1. Quantum processes in resonators with moving walls

    NASA Technical Reports Server (NTRS)

    Klimov, A. B.; Dodonov, V. V.

    1993-01-01

    The behavior of an electromagnetic field in an ideal cavity with an oscillating boundary is considered in the resonance long-time limit. The rates of photon creation from the vacuum and thermal states are evaluated. The squeezing coefficients for the field modes are found, as well as the backward reaction of the field on the vibrating wall.

  2. The dynamics of domain walls and strings

    NASA Technical Reports Server (NTRS)

    Gregory, Ruth; Haws, David; Garfinkle, David

    1989-01-01

    The leading order finite-width corrections to the equation of motion describing the motion of a domain wall are derived. The regime in which this equation of motion is invalid is discussed. Spherically and cylindrically symmetric solutions to this equation of motion are found. A misconception that has arisen in recent years regarding the rigidity (or otherwise) of cosmic strings is also clarified.

  3. Cell-wall dynamics in growing bacteria

    NASA Astrophysics Data System (ADS)

    Furchtgott, Leon; Wingreen, Ned; Huang, Kerwyn Casey

    2010-03-01

    Bacterial cells come in a large variety of shapes, and cell shape plays an important role in the regulation of many biological functions. Cell shape in bacterial cells is dictated by a cell wall composed of peptidoglycan, a polymer made up of long, stiff glycan strands and flexible peptide crosslinks. Although much is understood about the structural properties of peptidoglycan, little is known about the dynamics of cell wall organization in bacterial cells. In particular, during cell growth, how does the bacterial cell wall continuously expand and reorganize while maintaining cell shape? In order to investigate this question quantitatively, we model the cell wall of the Gram-negative bacterium Escherichia coli using a simple elastic model, in which glycan and peptide subunits are treated as springs with different spring constants and relaxed lengths. We consider the peptidoglycan network as a single-layered network of these springs under tension due to an internal osmotic pressure. Within this model, we simulate possible hypotheses for cell growth as different combinations of addition of new springs and breakage of old springs.

  4. Global Learning Communities: Science Classrooms without Walls

    ERIC Educational Resources Information Center

    Kerlin, Steven C.

    2009-01-01

    The physical walls of a classroom have typically acted as the boundary of school science learning communities. The participants in these learning communities are the students and the teacher in individual classrooms. These participants contribute to scientific discourse about a specific content area under study. Scientific learning communities, on…

  5. Administering Safety: Challenge Courses and Climbing Walls.

    ERIC Educational Resources Information Center

    Evans, Will

    1996-01-01

    A camp that is establishing a challenge course or climbing wall must ensure program safety. Discusses financial planning, selecting a contractor, adhering to standards for construction, inspections, staff training, screening of participants, and the administrative challenge of implementing and documenting proper actions. Sidebar discusses a study…

  6. Double-wall tubing for oil recovery

    NASA Technical Reports Server (NTRS)

    Back, L. H.; Carroll, W. F.; Jaffee, L. D.; Stimpson, L. D.

    1980-01-01

    Insulated double-wall tubing designed for steam injection oil recovery makes process more economical and allows deeper extension of wells. Higher quality wet steam is delivered through tubing to oil deposits with significant reductions in heat loss to surrounding rock allowing greater exploitation of previously unworkable reservoirs.

  7. Tearing Down the Wall: Literature and Science.

    ERIC Educational Resources Information Center

    Westcott, Warren B.; Spell, J. Everett

    1999-01-01

    Suggests English teachers might draw from authors such as Carl Sagan, Arthur C. Clarke, Mary Shelly and others: (1) to knock down the walls that separate science and literature; (2) to show their interrelationship; and (3) to instill enthusiasm for the study of both. (NH)

  8. The Discrete Site Sticky Wall Model.

    DTIC Science & Technology

    1986-05-27

    TECHNICAL REPORT #23 THE DISCRETE SITE STICKY WALL tMDEL by J.P. Badiali Laboratoire Propre No 15 de CNRS Physique des Liquides et Electrochimie Tour 22, 5e...Liquides et Electrochimie NTIS CRA&I DTIC TAB 5 Tour 22, 5e Etage, 4 Place Jussieu U’annou;.ced . J ’ tificatlo rn

  9. Salmonella typhimurium abscess of the chest wall

    PubMed Central

    Tonziello, Gilda; Valentinotti, Romina; Arbore, Enrico; Cassetti, Paolo; Luzzati, Roberto

    2013-01-01

    Patient: Male, 73 Final Diagnosis: Salmonella typhimurium abscess of the chest wall Symptoms: — Medication: Ciprofloxacin Clinical Procedure:— Specialty: Infectious Diseases Objective: Unusual clinical course Background: Non-typhoid Salmonella extra-intestinal infections usually develop in infants and in adult patients with pre-existing predisposing conditions. Blood stream infections and urinary tract infections are the most common clinical presentations, but other sites of infection may be involved as well. Case Report: We describe a case of invasive salmonellosis caused by Salmonella typhimurium involving the chest wall in a 73-year-old man. The patient had suffered from gastroenteritis followed by left basal pneumonia with pleural effusion 7 weeks before. The CT scan of the chest wall showed a pericostal abscess with shirt-stud morphology near the left last cartilaginous arch. The abscess was surgically drained and patient was cured after a 40-day ciprofloxacin treatment. Conclusions: A review of the literature on extra-intestinal non-typhoid salmonellosis shows that pleuropulmonary and soft-tissue infections are uncommon. We argue that non-typhoid Salmonella might be considered as a possible cause of chest wall abscess in individuals with recent history of gastroenteritis complicated by pneumonia and pleural effusion. PMID:24298305

  10. Subcooled Boiling Near a Heated Wall

    SciTech Connect

    T.A. Trabold; C.C. Maneri; P.F. Vassallo; D.M. Considine

    2000-10-27

    Experimental measurements of void fraction, bubble frequency, and velocity are obtained in subcooled R-134a flowing over a heated flat plate near an unheated wall and compared to analytical predictions. The measurements were obtained for a fixed system pressure and mass flow rate (P = 2.4 MPa and w = 106 kg/hr) at various inlet liquid temperatures. During the experiments, electrical power was applied at a constant rate to one side of the test section. The local void fraction data, acquired with a hot-film anemometer probe, showed the existence of a significant peak near the heated wall and a smaller secondary peak near the unheated wall for the larger inlet subcoolings. Local vapor velocity data, taken with the hot-film probe and a laser Doppler velocimeter, showed broad maxima near the centerline between the heated and unheated plates. Significant temperature gradients near the heated wall were observed for large inlet subcooling. Bubble size data, inferred from measurements of void fraction, bubble frequency and vapor velocity, when combined with the measured bubble chord length distributions illustrate the transition from pure three dimensional spherical to two-dimensional planar bubble flow, the latter being initiated when the bubbles fill the gap between the plates. These various two-phase flow measurements were used for development of a multidimensional, four-field calculational method; comparisons of the data to the calculations show reasonable agreement.

  11. Terahertz Conductivity of Single Walled Nanotube Films

    NASA Astrophysics Data System (ADS)

    Han, Jia-Guang; Zhu, Zhi-Yuan; He, Feng; Liao, Yi; Wang, Zhen-Xia; Zhang, Wei; Yu, Li-Ping; Sun, Li-Tao; Wang, Ting-Tai

    2003-09-01

    The conductivity of single walled nanotube films is investigated with a combination of the Maxwell-Garnett (MG) model and the Drude-Lorentzian (DL) model in the Terahertz region. A theoretical fit for Jeon's experiment is given and a decrease of the real conductivity with increasing frequency is predicted. Meanwhile, the MG and DL models are also discussed for different samples.

  12. Double-wall tubing for oil recovery

    NASA Technical Reports Server (NTRS)

    Back, L. H.; Carroll, W. F.; Jaffee, L. D.; Stimpson, L. D.

    1980-01-01

    Insulated double-wall tubing designed for steam injection oil recovery makes process more economical and allows deeper extension of wells. Higher quality wet steam is delivered through tubing to oil deposits with significant reductions in heat loss to surrounding rock allowing greater exploitation of previously unworkable reservoirs.

  13. Tearing Down the Wall: Literature and Science.

    ERIC Educational Resources Information Center

    Westcott, Warren B.; Spell, J. Everett

    1999-01-01

    Suggests English teachers might draw from authors such as Carl Sagan, Arthur C. Clarke, Mary Shelly and others: (1) to knock down the walls that separate science and literature; (2) to show their interrelationship; and (3) to instill enthusiasm for the study of both. (NH)

  14. Factors Influencing Ultrasound Echoes From Arterial Walls

    NASA Astrophysics Data System (ADS)

    Griffith, Jim; Maciel, Mario; Zalesky, Paul

    1988-04-01

    Significant progress in methods for the treatment of arterial disease has been made during the past several years. The trend towards least invasive therapies has led to an increasing need for instruments which quantify arterial disease status before, during, and after an intervention or treatment. Such instruments should provide safer and more effective disease treatment by providing the physician with a procedure guidance tool. The use of miniature ultrasound transducers, mounted at the distal end of a vascular catheter or probe, offers a promising method for producing images and quantitative measure-ment of arterial lumen and wall thickness. Several approaches have been suggested for placing the transducers in a probe configuration which is then mounted in a catheter and advanced to the vascular site of interest for image generation. The "best" probe configuration is defined by the specific questions of interest to the physician. It also depends upon transducer characteristics and how the sound beam "interacts" with the arterial wall. Imaging the small diameter coronary arteries, in particular, requires careful consideration of various transducer-tissue parameters. Transducer signal-to-noise ratio will likely be a critical parameter for systems designed to image healthy and diseased coronary arteries. The reported study shows how arterial wall echo amplitude changes as the angle between sound beam and wall varies. Changes are measured under carefully defined laboratory conditions.

  15. Hypoventilation: neuromuscular and chest wall disorders.

    PubMed

    Goldstein, R S

    1992-09-01

    Patients with neuromuscular and chest wall disorders are vulnerable at night when alterations in ventilatory mechanics and control associated with their disease are imposed on the changes in mechanics and control associated with sleep. The physiologic and clinical consequences of these events may be reversed by nocturnal mechanical ventilatory support.

  16. Reproducibility of airway wall thickness measurements

    NASA Astrophysics Data System (ADS)

    Schmidt, Michael; Kuhnigk, Jan-Martin; Krass, Stefan; Owsijewitsch, Michael; de Hoop, Bartjan; Peitgen, Heinz-Otto

    2010-03-01

    Airway remodeling and accompanying changes in wall thickness are known to be a major symptom of chronic obstructive pulmonary disease (COPD), associated with reduced lung function in diseased individuals. Further investigation of this disease as well as monitoring of disease progression and treatment effect demand for accurate and reproducible assessment of airway wall thickness in CT datasets. With wall thicknesses in the sub-millimeter range, this task remains challenging even with today's high resolution CT datasets. To provide accurate measurements, taking partial volume effects into account is mandatory. The Full-Width-at-Half-Maximum (FWHM) method has been shown to be inappropriate for small airways1,2 and several improved algorithms for objective quantification of airway wall thickness have been proposed.1-8 In this paper, we describe an algorithm based on a closed form solution proposed by Weinheimer et al.7 We locally estimate the lung density parameter required for the closed form solution to account for possible variations of parenchyma density between different lung regions, inspiration states and contrast agent concentrations. The general accuracy of the algorithm is evaluated using basic tubular software and hardware phantoms. Furthermore, we present results on the reproducibility of the algorithm with respect to clinical CT scans, varying reconstruction kernels, and repeated acquisitions, which is crucial for longitudinal observations.

  17. Visualizing domain wall and reverse domain superconductivity.

    PubMed

    Iavarone, M; Moore, S A; Fedor, J; Ciocys, S T; Karapetrov, G; Pearson, J; Novosad, V; Bader, S D

    2014-08-28

    In magnetically coupled, planar ferromagnet-superconductor (F/S) hybrid structures, magnetic domain walls can be used to spatially confine the superconductivity. In contrast to a superconductor in a uniform applied magnetic field, the nucleation of the superconducting order parameter in F/S structures is governed by the inhomogeneous magnetic field distribution. The interplay between the superconductivity localized at the domain walls and far from the walls leads to effects such as re-entrant superconductivity and reverse domain superconductivity with the critical temperature depending upon the location. Here we use scanning tunnelling spectroscopy to directly image the nucleation of superconductivity at the domain wall in F/S structures realized with Co-Pd multilayers and Pb thin films. Our results demonstrate that such F/S structures are attractive model systems that offer the possibility to control the strength and the location of the superconducting nucleus by applying an external magnetic field, potentially useful to guide vortices for computing application.

  18. Conductivity of single-walled carbon nanotubes

    SciTech Connect

    Gets, A. V.; Krainov, V. P.

    2016-12-15

    The conductivity of single-walled carbon nanotubes at low temperatures is calculated. It is shown that it is much higher than the well-known conductivity of a model 1D Fermi system. This is a purely quantum-mechanical effect.

  19. Uniform-Temperature Walls for Cloud Chambers

    NASA Technical Reports Server (NTRS)

    Fleischman, G.

    1985-01-01

    Flat heat pipes rapidly transfer heat to and from experimental volumes. Heat pipe vapor chamber carries heat to and from thermo electric modules. Critical surface acts as evaporator or condenser in cloud physics experiments. Used as walls of spaceborne atmospheric cloud chambers. On Earth, used as isothermal floors for environmental test chambers.

  20. Uniform-Temperature Walls for Cloud Chambers

    NASA Technical Reports Server (NTRS)

    Fleischman, G.

    1985-01-01

    Flat heat pipes rapidly transfer heat to and from experimental volumes. Heat pipe vapor chamber carries heat to and from thermo electric modules. Critical surface acts as evaporator or condenser in cloud physics experiments. Used as walls of spaceborne atmospheric cloud chambers. On Earth, used as isothermal floors for environmental test chambers.

  1. Micro-grooved heat transfer combustor wall

    NASA Technical Reports Server (NTRS)

    Ward, Steven D. (Inventor)

    1994-01-01

    A gas turbine engine hot section combustor liner is provided a non-film cooled portion of a heat transfer wall having a hot surface and a plurality of longitudinally extending micro-grooves disposed in the portion of the wall along the hot surface in a direction parallel to the direction of the hot gas flow. The depth of the micro-grooves is very small and on the order of magnitude of a predetermined laminar sublayer of a turbulent boundary layer. The micro-grooves are sized so as to inhibit heat transfer from the hot gas flow to the hot surface of the wall while reducing NOx emissions of the combustor relative to an otherwise similar combustor having a liner wall portion including film cooling apertures. In one embodiment the micro-grooves are about 0.001 inches deep and have a preferred depth range of from about 0.001 inches to 0.005 inches and which are square, rectangular, or triangular in cross-section and the micro-grooves are spaced about one width apart.

  2. Genetics Home Reference: abdominal wall defect

    MedlinePlus

    ... Aug;6(4):232-6. Citation on PubMed Islam S. Clinical care outcomes in abdominal wall defects. Curr ... Site Map Customer Support Selection Criteria for Links USA.gov Copyright Privacy Accessibility FOIA Viewers & Players U.S. ...

  3. Asbestos in Plaster and Wall Systems

    EPA Pesticide Factsheets

    This collection of letters and clarification on final rules provides guidance on Asbestos National Emissions Standard for Hazardous Air Pollutants for asbestos-containing join compounds, and asbestos-containing materials found in plaster and wall systems.

  4. Opportunity at the Wall 3-D

    NASA Image and Video Library

    2004-11-23

    NASA Mars Exploration Rover Opportunity reached the base of Burns Cliff, a portion of the inner wall of Endurance Crater in this anaglyph from the rover 285th martian day Nov. 11, 2004. 3D glasses are necessary to view this image.

  5. Education Ltd: Wall Street Eyes School Privatization.

    ERIC Educational Resources Information Center

    Bushweller, Kevin

    1997-01-01

    Describes Wall Street's growing interest in private education companies. Discusses the parallels between the emerging education industry of today and the fledgling health care industry of the 1970s. The acronym EMO (education management organization) is used to categorize companies that manage entire schools. Describes the niches created by the…

  6. Gravitation toward Walls among Human Subjects

    ERIC Educational Resources Information Center

    Dabbs, James M., Jr.; Wheeler, Patricia A.

    1976-01-01

    In two studies, college students (N=34) in a classroom corridor who walked near the wall ("gravitators") were contrasted with those who walked near the center ("non-gravitators"). Gravitators were lower than non-gravitators on Autonomy and Defendence and appeared to be less responsive to other persons. (Author)

  7. Gravitation toward Walls among Human Subjects

    ERIC Educational Resources Information Center

    Dabbs, James M., Jr.; Wheeler, Patricia A.

    1976-01-01

    In two studies, college students (N=34) in a classroom corridor who walked near the wall ("gravitators") were contrasted with those who walked near the center ("non-gravitators"). Gravitators were lower than non-gravitators on Autonomy and Defendence and appeared to be less responsive to other persons. (Author)

  8. Building a Lego wall: Sequential action selection.

    PubMed

    Arnold, Amy; Wing, Alan M; Rotshtein, Pia

    2017-05-01

    The present study draws together two distinct lines of enquiry into the selection and control of sequential action: motor sequence production and action selection in everyday tasks. Participants were asked to build 2 different Lego walls. The walls were designed to have hierarchical structures with shared and dissociated colors and spatial components. Participants built 1 wall at a time, under low and high load cognitive states. Selection times for correctly completed trials were measured using 3-dimensional motion tracking. The paradigm enabled precise measurement of the timing of actions, while using real objects to create an end product. The experiment demonstrated that action selection was slowed at decision boundary points, relative to boundaries where no between-wall decision was required. Decision points also affected selection time prior to the actual selection window. Dual-task conditions increased selection errors. Errors mostly occurred at boundaries between chunks and especially when these required decisions. The data support hierarchical control of sequenced behavior. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  9. Visualizing domain wall and reverse domain superconductivity

    PubMed Central

    Iavarone, M.; Moore, S. A.; Fedor, J.; Ciocys, S. T.; Karapetrov, G.; Pearson, J.; Novosad, V.; Bader, S. D.

    2014-01-01

    In magnetically coupled, planar ferromagnet-superconductor (F/S) hybrid structures, magnetic domain walls can be used to spatially confine the superconductivity. In contrast to a superconductor in a uniform applied magnetic field, the nucleation of the superconducting order parameter in F/S structures is governed by the inhomogeneous magnetic field distribution. The interplay between the superconductivity localized at the domain walls and far from the walls leads to effects such as re-entrant superconductivity and reverse domain superconductivity with the critical temperature depending upon the location. Here we use scanning tunnelling spectroscopy to directly image the nucleation of superconductivity at the domain wall in F/S structures realized with Co-Pd multilayers and Pb thin films. Our results demonstrate that such F/S structures are attractive model systems that offer the possibility to control the strength and the location of the superconducting nucleus by applying an external magnetic field, potentially useful to guide vortices for computing application. PMID:25164004

  10. Moving wall, continuous flow electronphoresis apparatus

    NASA Technical Reports Server (NTRS)

    Rhodes, Percy H. (Inventor); Snyder, Robert S. (Inventor)

    1988-01-01

    This invention relates generally to electrophoresis devices and more particularly to a moving wall, continuous flow device in which an electrophoresis chamber is angularly positionable with respect to the direction of moving belt walls. A frame with an electrophoresis chamber is rotatably supported between two synchronously driven belt walls. This allows the chamber to be angularly positionable with respect to the direction of belt travel, which compensates for electroosmotic flow within the electrophoresis chamber. Injection of a buffer solution via an opening and a homogenous sample stream via another opening is performed at the end of a chamber, and collection of buffer and the fractionated species particles is done by a conventional collection array at an opposite end of the chamber. Belts are driven at a rate which exactly matches the flow of buffer and sample through the chamber, which entrains the buffer to behave as a rigid electrophoretic medium, eliminating flow distortions (Poiseuille effect). Additionally, belt material for each belt is stored at one end of the device and is taken up by drive wheels at an opposite end. The novelty of this invention particularly lies in the electrophoresis chamber being angularly positionable between two moving belt walls in order to compensate for electroosmotic flow. Additionally, new belt material is continuously exposed within the chamber, minimizing flow distortion due to contamination of the belt material by the sample.

  11. Large eddy simulation of smooth-wall, transitional and fully rough-wall channel flow

    NASA Astrophysics Data System (ADS)

    Saito, Namiko; Pullin, Dale I.; Inoue, Michio

    2012-07-01

    Large eddy simulation (LES) is reported for both smooth and rough-wall channel flows at resolutions for which the roughness is subgrid. The stretched vortex, subgrid-scale model is combined with an existing wall-model that calculates the local friction velocity dynamically while providing a Dirichlet-like slip velocity at a slightly raised wall. This wall model is presently extended to include the effects of subgrid wall roughness by the incorporation of the Hama's roughness function Δ U^+(k_{sinfty }^+) that depends on some geometric roughness height ks∞ scaled in inner variables. Presently Colebrook's empirical roughness function is used but the model can utilize any given function of an arbitrary number of inner-scaled, roughness length parameters. This approach requires no change to the interior LES and can handle both smooth and rough walls. The LES is applied to fully turbulent, smooth, and rough-wall channel flow in both the transitional and fully rough regimes. Both roughness and Reynolds number effects are captured for Reynolds numbers Reb based on the bulk flow speed in the range 104-1010 with the equivalent Reτ, based on the wall-drag velocity uτ varying from 650 to 108. Results include a Moody-like diagram for the friction factor f = f(Reb, ɛ), ɛ = ks∞/δ, mean velocity profiles, and turbulence statistics. In the fully rough regime, at sufficiently large Reb, the mean velocity profiles show collapse in outer variables onto a roughness modified, universal, velocity-deficit profile. Outer-flow stream-wise turbulence intensities scale well with uτ for both smooth and rough-wall flow, showing a log-like profile. The infinite Reynolds number limits of both smooth and rough-wall flows are explored. An assumption that, for smooth-wall flow, the turbulence intensities scaled on uτ are bounded above by the sum of a logarithmic profile plus a finite function across the whole channel suggests that the infinite Reb limit is inviscid slip flow without

  12. Hot wire production of single-wall and multi-wall carbon nanotubes

    DOEpatents

    Dillon, Anne C.; Mahan, Archie H.; Alleman, Jeffrey L.

    2010-10-26

    Apparatus (210) for producing a multi-wall carbon nanotube (213) may comprise a process chamber (216), a furnace (217) operatively associated with the process chamber (216), and at least one filament (218) positioned within the process chamber (216). At least one power supply (220) operatively associated with the at least one filament (218) heats the at least one filament (218) to a process temperature. A gaseous carbon precursor material (214) operatively associated with the process chamber (216) provides carbon for forming the multi-wall carbon nanotube (213). A metal catalyst material (224) operatively associated with the process (216) catalyzes the formation of the multi-wall carbon nanotube (213).

  13. Knocking on the heaven's wall: pathogenesis of and resistance to biotrophic fungi at the cell wall.

    PubMed

    Schulze-Lefert, Paul

    2004-08-01

    New findings challenge the traditional view of the plant cell wall as passive structural barrier to invasion by fungal microorganisms. A surveillance system for cell wall integrity appears to sense perturbation of the cell wall structure upon fungal attack and is interconnected with known plant defence signalling pathways. Biotrophic fungi might manipulate this surveillance system for the establishment of biotrophy. The attempts of fungi to invade also induce a sub-cellular polarisation in attacked cells, which activates an ancient vesicle-associated resistance response that possibly enables the focal transport of regulatory cargo and the secretion of toxic cargo. The underlying resistance machinery might have been subverted by biotrophic fungi for pathogenesis.

  14. Measuring in-vitro extensibility of growth plant cell walls

    SciTech Connect

    Cosgrove, Daniel

    2011-01-01

    This article summarizes the theory and practical aspects of measuring cell wall properties by four different extensometer techniques and how the results of these methods relate to the concept and ideal measurement of cell wall extensibility in the context of cell growth. These in vivo techniques are particularly useful for studies of the molecular basis of cell wall extension. Measurements of breaking strength, elastic compliance, and plastic compliance may be informative about changes in cell wall structure, whereas measurements of wall stress relaxation and creep are sensitive to both changes in wall structure and wall-loosening processes, such as those mediated by expansins and some lytic enzymes. A combination of methods is needed to obtain a broader view of cell wall behavior and properties connected with the concept of cell wall extensibility.

  15. Wall relaxation and the driving forces for cell expansive growth

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.

    1987-01-01

    When water uptake by growing cells is prevented, the turgor pressure and the tensile stress in the cell wall are reduced by continued wall loosening. This process, termed in vivo stress relaxation, provides a new way to study the dynamics of wall loosening and to measure the wall yield threshold and the physiological wall extensibility. Stress relaxation experiments indicate that wall stress supplies the mechanical driving force for wall yielding. Cell expansion also requires water absorption. The driving force for water uptake during growth is created by wall relaxation, which lowers the water potential of the expanding cells. New techniques for measuring this driving force show that it is smaller than believed previously; in elongating stems it is only 0.3 to 0.5 bar. This means that the hydraulic resistance of the water transport pathway is small and that rate of cell expansion is controlled primarily by wall loosening and yielding.

  16. Measuring in vitro extensibility of growing plant cell walls.

    PubMed

    Cosgrove, Daniel J

    2011-01-01

    This article summarizes the theory and practical aspects of measuring cell wall properties by four different extensometer techniques and how the results of these methods relate to the concept and ideal measurement of cell wall extensibility in the context of cell growth. These in vivo techniques are particularly useful for studies of the molecular basis of cell wall extension. Measurements of breaking strength, elastic compliance, and plastic compliance may be informative about changes in cell wall structure, whereas measurements of wall stress relaxation and creep are sensitive to both changes in wall structure and wall-loosening processes, such as those mediated by expansins and some lytic enzymes. A combination of methods is needed to obtain a broader view of cell wall behavior and properties connected with the concept of cell wall extensibility.

  17. Wall relaxation and the driving forces for cell expansive growth

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.

    1987-01-01

    When water uptake by growing cells is prevented, the turgor pressure and the tensile stress in the cell wall are reduced by continued wall loosening. This process, termed in vivo stress relaxation, provides a new way to study the dynamics of wall loosening and to measure the wall yield threshold and the physiological wall extensibility. Stress relaxation experiments indicate that wall stress supplies the mechanical driving force for wall yielding. Cell expansion also requires water absorption. The driving force for water uptake during growth is created by wall relaxation, which lowers the water potential of the expanding cells. New techniques for measuring this driving force show that it is smaller than believed previously; in elongating stems it is only 0.3 to 0.5 bar. This means that the hydraulic resistance of the water transport pathway is small and that rate of cell expansion is controlled primarily by wall loosening and yielding.

  18. Wall relaxation and the driving forces for cell expansive growth.

    PubMed

    Cosgrove, D J

    1987-01-01

    When water uptake by growing cells is prevented, the turgor pressure and the tensile stress in the cell wall are reduced by continued wall loosening. This process, termed in vivo stress relaxation, provides a new way to study the dynamics of wall loosening and to measure the wall yield threshold and the physiological wall extensibility. Stress relaxation experiments indicate that wall stress supplies the mechanical driving force for wall yielding. Cell expansion also requires water absorption. The driving force for water uptake during growth is created by wall relaxation, which lowers the water potential of the expanding cells. New techniques for measuring this driving force show that it is smaller than believed previously; in elongating stems it is only 0.3 to 0.5 bar. This means that the hydraulic resistance of the water transport pathway is small and that rate of cell expansion is controlled primarily by wall loosening and yielding.

  19. Active wall following by Mexican blind cavefish (Astyanax mexicanus).

    PubMed

    Patton, Paul; Windsor, Shane; Coombs, Sheryl

    2010-11-01

    When introduced into a novel environment that limits or prevents vision, a variety of species including Mexican blind cavefish (Astyanax mexicanus) exhibit wall-following behaviors. It is often assumed that wall following serves an exploratory function, but this assertion remains untested against alternative artifactual explanations. Here, we test whether wall following by cavefish is a purposeful behavior in which fish actively maintain a close relationship with the wall, or an artifactual consequence of being enclosed in a small concave arena, in which fish turn slightly to avoid the wall whenever it impedes forward movement. Wall-following abilities of fish were tested in a large, goggle-shaped arena, where forward motion along the convex wall was unimpeded. In this circumstance, cavefish continued to follow the wall at frequencies significantly above chance levels. Lateral line inactivation significantly reduced the ability of fish to follow convex, but not concave or straight, walls. Wall-following abilities of normal fish decreased with decreasing radius of wall convex curvature. Our results demonstrate that cavefish actively follow walls of varying contours. Radius-of-curvature effects coupled with the difficulties posed by convex walls to lateral line-deprived fish suggest a partially complementary use of tactile and lateral line information to regulate distance from the wall.

  20. Hydrodynamic interaction of micro-swimmers near a wall

    PubMed Central

    Li, Gao-Jin

    2015-01-01

    The hydrodynamics of an archetypal low-Reynolds number swimmer, called “squirmer”, near a wall has been numerically studied. For a single squirmer, depending on the swimming mechanism, three different modes are distinguished: (a) the squirmer escaping from the wall, (b) the squirmer swimming along the wall at a constant distance and orientation angle, and (c) the squirmer swimming near the wall in a periodic trajectory. The role of inertial effects on the near-wall motion of the squirmer is quantified. The dynamics of multiple squirmers swimming between two walls is found to be very different from a single squirmer. Near-wall accumulation of squirmers are observed. At a relatively small concentration c = 0.1, around 60 – 80% of the squirmers are accumulated near the walls and attraction of pushers and pullers towards the wall is stronger than neutral squirmers. Near-wall squirmers orient normal to the wall, while in the bulk region, the squirmers are mostly oriented parallel to the wall. At a high concentration, c = 0.4, the percentage of the near-wall squirmers is around 40%. The orientation angle of squirmers in the bulk region is more uniformly distributed at high concentrations. In the near-wall region, pullers repel each other, while pushers are attracted to each other and form clusters. PMID:25122372

  1. Cell Wall Loosening in the Fungus, Phycomyces blakesleeanus

    PubMed Central

    Ortega, Joseph K. E.; Truong, Jason T.; Munoz, Cindy M.; Ramirez, David G.

    2015-01-01

    A considerable amount of research has been conducted to determine how cell walls are loosened to produce irreversible wall deformation and expansive growth in plant and algal cells. The same cannot be said about fungal cells. Almost nothing is known about how fungal cells loosen their walls to produce irreversible wall deformation and expansive growth. In this study, anoxia is used to chemically isolate the wall from the protoplasm of the sporangiophores of Phycomyces blakesleeanus. The experimental results provide direct evidence of the existence of chemistry within the fungal wall that is responsible for wall loosening, irreversible wall deformation and elongation growth. In addition, constant-tension extension experiments are conducted on frozen-thawed sporangiophore walls to obtain insight into the wall chemistry and wall loosening mechanism. It is found that a decrease in pH to 4.6 produces creep extension in the frozen-thawed sporangiophore wall that is similar, but not identical, to that found in frozen-thawed higher plant cell walls. Experimental results from frozen-thawed and boiled sporangiophore walls suggest that protein activity may be involved in the creep extension. PMID:27135318

  2. Proportionality between chest wall resistance and elastance.

    PubMed

    Barnas, G M; Stamenović, D; Fredberg, J J

    1991-02-01

    Fredberg and Stamenovic (J. Appl. Physiol. 67: 2408-2419, 1989) demonstrated a relatively robust phenomenological relationship between resistance (R) and elastance (E) of lung tissue during external forcing. The relationship can be expressed as omega R = eta E, where omega = 2 pi times forcing frequency and eta is hysteresivity; they found eta to be remarkably invariant under a wide range of circumstances. From data gathered in previous experiments, we have tested the adequacy and utility of this phenomenological description for the chest wall (eta w) and its major compartments, the rib cage (eta rc), diaphragm-abdomen (eta d-a), and belly wall (eta bw+). For forcing frequencies and tidal volumes within the normal range of breathing, we found that eta w remained in a relatively narrow range (0.27-0.37) and that neither eta w nor the compartmental eta's changed much with frequency or tidal volume. Compared with eta w, eta rc tended to be slightly low, whereas eta d-a tended to be slightly higher than eta w. However, at higher frequencies (greater than 1 Hz) all eta's increased appreciably with frequency. During various static nonrespiratory maneuvers involving use of respiratory muscles, eta w increased up to twofold. We conclude that in the normal ranges of breathing frequency and tidal volume 1) elastic and dissipative processes within the chest wall appear to be coupled, 2) eta's of the various component parts of the chest wall are well matched, 3) respiratory muscle contraction increases the ratio of cyclic dissipative losses to energy storage, and 4) R of the relaxed chest wall can be estimated from E.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Liquid Metal Walls and the Belt Pinch

    NASA Astrophysics Data System (ADS)

    Kotschenreuther, Michael; Dorland, W.; Manickam, J.; Menard, J.; Miller, R.

    2000-10-01

    High flux reactor designs have placed the MHD stabilizing shell well away from the first wall due to breeding and reliability issues. Liquid metal shells containing Li may allow close shells, with much higher elongation (kappa), beta and power density. MHD stability of equilibria with kappa = 2 - 6 and high bootstrap fraction are examined using JSOLVER plus PEST and TOQ plus BALOO. Compared to kappa = 2, stable beta increases by 2.5 for kappa = 3 and 5 for kappa = 6 (with little change in normalized beta). External mode stability (n = 1-10 ) with a wall is similar for kappa = 2-6; a wall at b/a 1.2-1.3 give stability. Resistive wall mode evolution is examined using the new code WALLMODE; feedback power is evaluated using dynamic Monte Carlo simulations (similar to ARIES studies). N = 0 vertical modes are acceptable with a 2-4 cm Li shell at b/a 1.05 -1.1. Resistive wall kink modes for model current profiles are stabilizable by feedback and/or liquid flow as low as 20 m/s; interfacing with PEST is in progress to examinine realistic equilibria. Modest indendation gives bootstrap island stability. Comprehensive gyrokinetic simulations with GS2 find a strong improvement with kappa for 1) ExB shearing compared to ITG/drift mode growth rates and 2) transport in nonlinear ETG simulations. Also, low edge recycling (density) boundary conditions substantially improve H mode pedestal stabilty, for additional global confinement improvement. Even with H mode scaling law confinement, kappa =6 gives ignition in a .8 m major radius device with Cu coils (12T at the coil).

  4. Algorithm of chest wall keloid treatment

    PubMed Central

    Long, Xiao; Zhang, Mingzi; Wang, Yang; Zhao, Ru; Wang, Youbin; Wang, Xiaojun

    2016-01-01

    Abstract Keloids are common in the Asian population. Multiple or huge keloids can appear on the chest wall because of its tendency to develop acne, sebaceous cyst, etc. It is difficult to find an ideal treatment for keloids in this area due to the limit of local soft tissues and higher recurrence rate. This study aims at establishing an individualized protocol that could be easily applied according to the size and number of chest wall keloids. A total of 445 patients received various methods (4 protocols) of treatment in our department from September 2006 to September 2012 according to the size and number of their chest wall keloids. All of the patients received adjuvant radiotherapy in our hospital. Patient and Observer Scar Assessment Scale (POSAS) was used to assess the treatment effect by both doctors and patients. With mean follow-up time of 13 months (range: 6–18 months), 362 patients participated in the assessment of POSAS with doctors. Both the doctors and the patients themselves used POSAS to evaluate the treatment effect. The recurrence rate was 0.83%. There was an obvious significant difference (P < 0.001) between the before-surgery score and the after-surgery score from both doctors and patients, indicating that both doctors and patients were satisfied with the treatment effect. Our preliminary clinical result indicates that good clinical results could be achieved by choosing the proper method in this algorithm for Chinese patients with chest wall keloids. This algorithm could play a guiding role for surgeons when dealing with chest wall keloid treatment. PMID:27583896

  5. Assembly of the Yeast Cell Wall

    PubMed Central

    Cabib, Enrico; Farkas, Vladimir; Kosík, Ondrej; Blanco, Noelia; Arroyo, Javier; McPhie, Peter

    2008-01-01

    The cross-linking of polysaccharides to assemble new cell wall in fungi requires mechanisms by which a preexisting linkage is broken for each new one made, to allow for the absence of free energy sources outside the plasma membrane. Previous work showed that Crh1p and Crh2p, putative transglycosylases, are required for the linkage of chitin to β(1–3)glucose branches of β(1–6)glucan in the cell wall of budding yeast. To explore the linking reaction in vivo and in vitro, we used fluorescent sulforhodamine-linked laminari-oligosaccharides as artificial chitin acceptors. In vivo, fluorescence was detected in bud scars and at a lower level in the cell contour, both being dependent on the CRH genes. The linking reaction was also shown in digitonin-permeabilized cells, with UDP-N-acetylglucosamine as the substrate for nascent chitin production. Both the nucleotide and the Crh proteins were required here. A gas1 mutant that overexpresses Crh1p showed very high fluorescence both in intact and permeabilized cells. In the latter, fluorescence was still incorporated in patches in the absence of UDP-GlcNAc. Isolated cell walls of this strain, when incubated with sulforhodamine-oligosaccharide, also showed Crhp-dependent fluorescence in patches, which were identified as bud scars. In all three systems, binding of the fluorescent material to chitin was verified by chitinase digestion. Moreover, the cell wall reaction was inhibited by chitooligosaccharides. These results demonstrate that the Crh proteins act by transferring chitin chains to β(1–6)glucan, with a newly observed high activity in the bud scar. The importance of transglycosylation for cell wall assembly is thus firmly established. PMID:18694928

  6. Complexity of the transcriptional network controlling secondary wall biosynthesis.

    PubMed

    Zhong, Ruiqin; Ye, Zheng-Hua

    2014-12-01

    Secondary walls in the form of wood and fibers are the most abundant biomass produced by vascular plants, and are important raw materials for many industrial uses. Understanding how secondary walls are constructed is of significance in basic plant biology and also has far-reaching implications in genetic engineering of plant biomass better suited for various end uses, such as biofuel production. Secondary walls are composed of three major biopolymers, i.e., cellulose, hemicelluloses and lignin, the biosynthesis of which requires the coordinated transcriptional regulation of all their biosynthesis genes. Genomic and molecular studies have identified a number of transcription factors, whose expression is associated with secondary wall biosynthesis. We comprehensively review how these secondary wall-associated transcription factors function together to turn on the secondary wall biosynthetic program, which leads to secondary wall deposition in vascular plants. The transcriptional network regulating secondary wall biosynthesis employs a multi-leveled feed-forward loop regulatory structure, in which the top-level secondary wall NAC (NAM, ATAF1/2 and CUC2) master switches activate the second-level MYB master switches and they together induce the expression of downstream transcription factors and secondary wall biosynthesis genes. Secondary wall NAC master switches and secondary wall MYB master switches bind to and activate the SNBE (secondary wall NAC binding element) and SMRE (secondary wall MYB-responsive element) sites, respectively, in their target gene promoters. Further investigation of what and how developmental signals trigger the transcriptional network to regulate secondary wall biosynthesis and how different secondary wall-associated transcription factors function cooperatively in activating secondary wall biosynthetic pathways will lead to a better understanding of the molecular mechanisms underlying the transcriptional control of secondary wall biosynthesis.

  7. Characterization of the Sclerotinia sclerotiorum cell wall proteome.

    PubMed

    Liu, Longzhou; Free, Stephen J

    2016-08-01

    We used a proteomic analysis to identify cell wall proteins released from Sclerotinia sclerotiorum hyphal and sclerotial cell walls via a trifluoromethanesulfonic acid (TFMS) digestion. Cell walls from hyphae grown in Vogel's glucose medium (a synthetic medium lacking plant materials), from hyphae grown in potato dextrose broth and from sclerotia produced on potato dextrose agar were used in the analysis. Under the conditions used, TFMS digests the glycosidic linkages in the cell walls to release intact cell wall proteins. The analysis identified 24 glycosylphosphatidylinositol (GPI)-anchored cell wall proteins and 30 non-GPI-anchored cell wall proteins. We found that the cell walls contained an array of cell wall biosynthetic enzymes similar to those found in the cell walls of other fungi. When comparing the proteins in hyphal cell walls grown in potato dextrose broth with those in hyphal cell walls grown in the absence of plant material, it was found that a core group of cell wall biosynthetic proteins and some proteins associated with pathogenicity (secreted cellulases, pectin lyases, glucosidases and proteases) were expressed in both types of hyphae. The hyphae grown in potato dextrose broth contained a number of additional proteins (laccases, oxalate decarboxylase, peroxidase, polysaccharide deacetylase and several proteins unique to Sclerotinia and Botrytis) that might facilitate growth on a plant host. A comparison of the proteins in the sclerotial cell wall with the proteins in the hyphal cell wall demonstrated that sclerotia formation is not marked by a major shift in the composition of cell wall protein. We found that the S. sclerotiorum cell walls contained 11 cell wall proteins that were encoded only in Sclerotinia and Botrytis genomes. © 2015 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.

  8. OCT assessment of aortic wall degradation for surgical guidance

    NASA Astrophysics Data System (ADS)

    Real, E.; Val-Bernal, J. F.; Pontón, A.; Calvo Díez, M.; Mayorga, M.; Revuelta, J. M.; López-Higuera, J. M.; Conde, O. M.

    2014-05-01

    The degradation of the wall in large cardiovascular vessels, such as the aorta artery, induces weakness in the vessel that can lead to the formation of aneurysms and the rupture of the vessel. Characterization of the wall integrity is assessed by OCT for future intraoperative assistance in aneurysm graft surgery interventions. Optical Coherence Tomography (OCT) provides cross sectional images of the wall of the aortic media layer. Wall degradations appear as spatial anomalies in the reflectivity profile through the wall thickness. Wall degradation assessment is proposed by automatic identification and dimensioning of these anomalies within the homogeneous surrounding tissue.

  9. Antiferromagnetic Domain Wall Motion Driven by Spin-Orbit Torques.

    PubMed

    Shiino, Takayuki; Oh, Se-Hyeok; Haney, Paul M; Lee, Seo-Won; Go, Gyungchoon; Park, Byong-Guk; Lee, Kyung-Jin

    2016-08-19

    We theoretically investigate the dynamics of antiferromagnetic domain walls driven by spin-orbit torques in antiferromagnet-heavy-metal bilayers. We show that spin-orbit torques drive antiferromagnetic domain walls much faster than ferromagnetic domain walls. As the domain wall velocity approaches the maximum spin-wave group velocity, the domain wall undergoes Lorentz contraction and emits spin waves in the terahertz frequency range. The interplay between spin-orbit torques and the relativistic dynamics of antiferromagnetic domain walls leads to the efficient manipulation of antiferromagnetic spin textures and paves the way for the generation of high frequency signals from antiferromagnets.

  10. Antiferromagnetic domain wall motion driven by spin-orbit torques

    PubMed Central

    Shiino, Takayuki; Oh, Se-Hyeok; Haney, Paul M.; Lee, Seo-Won; Go, Gyungchoon; Park, Byong-Guk; Lee, Kyung-Jin

    2016-01-01

    We theoretically investigate dynamics of antiferromagnetic domain walls driven by spin-orbit torques in antiferromagnet/heavy metal bilayers. We show that spin-orbit torques drive antiferromagnetic domain walls much faster than ferromagnetic domain walls. As the domain wall velocity approaches the maximum spin-wave group velocity, the domain wall undergoes Lorentz contraction and emits spin-waves in the terahertz frequency range. The interplay between spin-orbit torques and the relativistic dynamics of antiferromagnetic domain walls leads to the efficient manipulation of antiferromagnetic spin textures and paves the way for the generation of high frequency signals from antiferromagnets. PMID:27588878

  11. Liquid-Gas Mixtures in Contact with Walls: Molecular Simulations

    NASA Astrophysics Data System (ADS)

    Markus Dammer, Stephan

    2005-11-01

    We perform molecular dynamics simulations of liquid-gas mixtures in contact to solid walls. We present results concerning Lennard-Jones systems composed of three particle species, namely liquid, foreign gas, and wall particles, which are frozen on a lattice: (i) Close to the wall we observe a layering of the fluid which becomes more pronounced for increasingly hydrophilic walls. (ii) Close to smooth hydrophobic walls we find a two orders of magnitude increase in the number density of gas, which will favor bubble nucleation. (iii) To characterize the walls, we determined the contact angle by simulations of droplets and compare the result to Laplace's estimate of surface energies.

  12. Enzymes and other agents that enhance cell wall extensibility

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.

    1999-01-01

    Polysaccharides and proteins are secreted to the inner surface of the growing cell wall, where they assemble into a network that is mechanically strong, yet remains extensible until the cells cease growth. This review focuses on the agents that directly or indirectly enhance the extensibility properties of growing walls. The properties of expansins, endoglucanases, and xyloglucan transglycosylases are reviewed and their postulated roles in modulating wall extensibility are evaluated. A summary model for wall extension is presented, in which expansin is a primary agent of wall extension, whereas endoglucanases, xyloglucan endotransglycosylase, and other enzymes that alter wall structure act secondarily to modulate expansin action.

  13. Enzymes and other agents that enhance cell wall extensibility

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.

    1999-01-01

    Polysaccharides and proteins are secreted to the inner surface of the growing cell wall, where they assemble into a network that is mechanically strong, yet remains extensible until the cells cease growth. This review focuses on the agents that directly or indirectly enhance the extensibility properties of growing walls. The properties of expansins, endoglucanases, and xyloglucan transglycosylases are reviewed and their postulated roles in modulating wall extensibility are evaluated. A summary model for wall extension is presented, in which expansin is a primary agent of wall extension, whereas endoglucanases, xyloglucan endotransglycosylase, and other enzymes that alter wall structure act secondarily to modulate expansin action.

  14. Two- and three-dimensional model and wall data from a flexible-walled transonic test section

    NASA Technical Reports Server (NTRS)

    Goodyer, M. J.; Cook, I. D.

    1984-01-01

    Both two- and three-dimensional model testing is being carried out in the transonic flexible-walled wind tunnel test section. The test section has flexible top and bottom walls with rigid sidewalls. Interference is eliminated by adjustments based on data taken at walls in two dimensional models. Cast-7 data will illustrate agreement between various flexible-walled tunnels. In three-dimensional models interference cannot be eliminated but wall adjustments can control and relieve the principal sources of wall-induced errors. Estimates of magnitudes of the control which may be exercised on flow by movement of one wall jack are presented. A wall control algorithm (still in analytic development stage) based on use of this data is described. Brief examples of control of wall-induced perturbations in region of model are given.

  15. [Chest Wall Reconstruction Using Titanium Plates Sandwiched Between Sheets after Resection of Chest Wall Chondrosarcoma].

    PubMed

    Endoh, Makoto; Oizumi, Hiroyuki; Kato, Hirohisa; Suzuki, Jun; Watarai, Hikaru; Hamada, Akira; Suzuki, Katsuyuki; Takahashi, Ai; Nakahashi, Kenta; Sugawara, Masato; Tsuchiya, Takashi; Sadahiro, Mitsuaki

    2016-07-01

    Extensive chest wall resection carries the risk of difficult reconstruction and surgical complications. We report our experience on chest wall reconstruction using titanium plates for a wide thoracic defect after tumor resection. A 74-year-old man was diagnosed with chondrosarcoma of the 6th rib on the right. He needed extensive chest wall resection because of skip lesions on 4th rib noted on operative inspection, leaving a defect measuring 33 × 20 cm. Reconstruction using 5 transverse titanium plates sandwiched between an expanded polytetrafluoroethylene patch and a polypropylene mesh sheet stabilized the chest wall. This reconstruction allowed successful separation from ventilatory support after operation. The postoperative course was uneventful, and he was discharged on postoperative day 20. The advantages of this form of reconstruction over conventional prostheses are rigidity, and stability and usability.

  16. Polysaccharide-degrading Enzymes are Unable to Attack Plant Cell Walls without Prior Action by a "Wall-modifying Enzyme".

    PubMed

    Karr, A L; Albersheim, P

    1970-07-01

    A study of the degradation of plant cell walls by the mixture of enzymes present in Pectinol R-10 is described. A "wall-modifying enzyme" has been purified from this mixture by a combination of diethylaminoethyl cellulose, Bio Gel P-100, and carboxymethyl cellulose chromatography. Treatment of cell walls with the "wall-modifying enzyme" is shown to be a necessary prerequisite to wall degradation catalyzed by a mixture of polysaccharide-degrading enzymes prepared from Pectinol R-10 or by an alpha-galactosidase secreted by the pathogenic fungus Colletotrichum lindemuthianum. The action of the "wall-modifying enzyme" on cell walls is shown to result in both a release of water-soluble, 70% ethanol-insoluble polymers and an alteration of the residual cell wall. A purified preparation of the "wall-modifying enzyme" is unable to degrade a wide variety of polysaccharide, glycoside, and peptide substrates. However, the purified preparation of wall-modifying enzyme has a limited ability to degrade polygalacturonic acid. The fact that polygalacturonic acid inhibits the ability of the "wall-modifying enzyme" to affect cell walls suggests that the "wall-modifying enzyme" may be responsible for the limited polygalacturonic acid-degrading activity present in the purified preparation. The importance of a wall-modifying enzyme in developmental processes and in pathogenesis is discussed.

  17. Cell wall-related proteins of unknown function: missing links in plant cell wall development.

    PubMed

    Mewalal, Ritesh; Mizrachi, Eshchar; Mansfield, Shawn D; Myburg, Alexander A

    2014-06-01

    Lignocellulosic biomass is an important feedstock for the pulp and paper industry as well as emerging biofuel and biomaterial industries. However, the recalcitrance of the secondary cell wall to chemical or enzymatic degradation remains a major hurdle for efficient extraction of economically important biopolymers such as cellulose. It has been estimated that approximately 10-15% of about 27,000 protein-coding genes in the Arabidopsis genome are dedicated to cell wall development; however, only about 130 Arabidopsis genes thus far have experimental evidence validating cell wall function. While many genes have been implicated through co-expression analysis with known genes, a large number are broadly classified as proteins of unknown function (PUFs). Recently the functionality of some of these unknown proteins in cell wall development has been revealed using reverse genetic approaches. Given the large number of cell wall-related PUFs, how do we approach and subsequently prioritize the investigation of such unknown genes that may be essential to or influence plant cell wall development and structure? Here, we address the aforementioned question in two parts; we first identify the different kinds of PUFs based on known and predicted features such as protein domains. Knowledge of inherent features of PUFs may allow for functional inference and a concomitant link to biological context. Secondly, we discuss omics-based technologies and approaches that are helping identify and prioritize cell wall-related PUFs by functional association. In this way, hypothesis-driven experiments can be designed for functional elucidation of many proteins that remain missing links in our understanding of plant cell wall biosynthesis. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. Rotational stabilization of the resistive wall modes in tokamaks with a ferritic wall

    SciTech Connect

    Pustovitov, V. D.; Yanovskiy, V. V.

    2015-03-15

    The dynamics of the rotating resistive wall modes (RWMs) is analyzed in the presence of a uniform ferromagnetic resistive wall with μ{sup ^}≡μ/μ{sub 0}≤4 (μ is the wall magnetic permeability, and μ{sub 0} is the vacuum one). This mimics a possible arrangement in ITER with ferromagnetic steel in test blanket modules or in future experiments in JT-60SA tokamak [Y. Kamada, P. Barabaschi, S. Ishida, the JT-60SA Team, and JT-60SA Research Plan Contributors, Nucl. Fusion 53, 104010 (2013)]. The earlier studies predict that such a wall must provide a destabilizing influence on the plasma by reducing the beta limit and increasing the growth rates, compared to the reference case with μ{sup ^}=1. This is true for the locked modes, but the presented results show that the mode rotation changes the tendency to the opposite. At μ{sup ^}>1, the rotational stabilization related to the energy sink in the wall becomes even stronger than at μ{sup ^}=1, and this “external” effect develops at lower rotation frequency, estimated as several kHz at realistic conditions. The study is based on the cylindrical dispersion relation valid for arbitrary growth rates and frequencies. This relation is solved numerically, and the solutions are compared with analytical dependences obtained for slow (s/d{sub w}≫1) and fast (s/d{sub w}≪1) “ferromagnetic” rotating RWMs, where s is the skin depth and d{sub w} is the wall thickness. It is found that the standard thin-wall modeling becomes progressively less reliable at larger μ{sup ^}, and the wall should be treated as magnetically thick. The analysis is performed assuming only a linear plasma response to external perturbations without constraints on the plasma current and pressure profiles.

  19. Reconstitution of a secondary cell wall in a secondary cell wall-deficient Arabidopsis mutant.

    PubMed

    Sakamoto, Shingo; Mitsuda, Nobutaka

    2015-02-01

    The secondary cell wall constitutes a rigid frame of cells in plant tissues where rigidity is required. Deposition of the secondary cell wall in fiber cells contributes to the production of wood in woody plants. The secondary cell wall is assembled through co-operative activities of many enzymes, and their gene expression is precisely regulated by a pyramidal cascade of transcription factors. Deposition of a transmuted secondary cell wall in empty fiber cells by expressing selected gene(s) in this cascade has not been attempted previously. In this proof-of-concept study, we expressed chimeric activators of 24 transcription factors that are preferentially expressed in the stem, in empty fiber cells of the Arabidopsis nst1-1 nst3-1 double mutant, which lacks a secondary cell wall in fiber cells, under the control of the NST3 promoter. The chimeric activators of MYB46, SND2 and ANAC075, as well as NST3, reconstituted a secondary cell wall with different characteristics from those of the wild type in terms of its composition. The transgenic lines expressing the SND2 or ANAC075 chimeric activator showed increased glucose and xylose, and lower lignin content, whereas the transgenic line expressing the MYB46 chimeric activator showed increased mannose content. The expression profile of downstream genes in each transgenic line was also different from that of the wild type. This study proposed a new screening strategy to identify factors of secondary wall formation and also suggested the potential of the artificially reconstituted secondary cell walls as a novel raw material for production of bioethanol and other chemicals. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  20. Engineering the Oryza sativa cell wall with rice NAC transcription factors regulating secondary wall formation

    PubMed Central

    Yoshida, Kouki; Sakamoto, Shingo; Kawai, Tetsushi; Kobayashi, Yoshinori; Sato, Kazuhito; Ichinose, Yasunori; Yaoi, Katsuro; Akiyoshi-Endo, Miho; Sato, Hiroko; Takamizo, Tadashi; Ohme-Takagi, Masaru; Mitsuda, Nobutaka

    2013-01-01

    Plant tissues that require structural rigidity synthesize a thick, strong secondary cell wall of lignin, cellulose and hemicelluloses in a complicated bridged structure. Master regulators of secondary wall synthesis were identified in dicots, and orthologs of these regulators have been identified in monocots, but regulation of secondary cell wall formation in monocots has not been extensively studied. Here we demonstrate that the rice transcription factors SECONDARY WALL NAC DOMAIN PROTEINs (SWNs) can regulate secondary wall formation in rice (Oryza sativa) and are potentially useful for engineering the monocot cell wall. The OsSWN1 promoter is highly active in sclerenchymatous cells of the leaf blade and less active in xylem cells. By contrast, the OsSWN2 promoter is highly active in xylem cells and less active in sclerenchymatous cells. OsSWN2 splicing variants encode two proteins; the shorter protein (OsSWN2S) has very low transcriptional activation ability, but the longer protein (OsSWN2L) and OsSWN1 have strong transcriptional activation ability. In rice, expression of an OsSWN2S chimeric repressor, driven by the OsSWN2 promoter, resulted in stunted growth and para-wilting (leaf rolling and browning under normal water conditions) due to impaired vascular vessels. The same OsSWN2S chimeric repressor, driven by the OsSWN1 promoter, caused a reduction of cell wall thickening in sclerenchymatous cells, a drooping leaf phenotype, reduced lignin and xylose contents and increased digestibility as forage. These data suggest that OsSWNs regulate secondary wall formation in rice and manipulation of OsSWNs may enable improvements in monocotyledonous crops for forage or biofuel applications. PMID:24098302