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Sample records for nemad ritasid wall

  1. Great Walls.

    ERIC Educational Resources Information Center

    Blackburn, Steve; Moore, Tim

    1996-01-01

    Explains why installing a well-designed indoor climbing wall can draw new users to an athletic facility. Climbing-wall design elements and gear are discussed and a checklist for working with contractors is provided.(GR)

  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. 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.

  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. 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.

  8. 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.

  9. 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.

  10. Fluidized wall for protecting fusion chamber walls

    SciTech Connect

    Maniscalco, J.A.; Meier, W.R.

    1982-08-17

    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 lithiumceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Cell wall integrity

    PubMed Central

    Pogorelko, Gennady; Lionetti, Vincenzo; Bellincampi, Daniela; Zabotina, Olga

    2013-01-01

    The plant cell wall, a dynamic network of polysaccharides and glycoproteins of significant compositional and structural complexity, functions in plant growth, development and stress responses. In recent years, the existence of plant cell wall integrity (CWI) maintenance mechanisms has been demonstrated, but little is known about the signaling pathways involved, or their components. Examination of key mutants has shed light on the relationships between cell wall remodeling and plant cell responses, indicating a central role for the regulatory network that monitors and controls cell wall performance and integrity. In this review, we present a short overview of cell wall composition and discuss post-synthetic cell wall modification as a valuable approach for studying CWI perception and signaling pathways. PMID:23857352

  18. 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.

  19. '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.

  20. 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.

  1. 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.

  2. 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…

  3. 5. Detail of bin wall, showing the thinner exterior wall ...

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

    5. Detail of bin wall, showing the thinner exterior wall next to the inner wall with its alternating courses of channel tile and hollow tile. - Saint Anthony Elevator No. 3, 620 Malcom Avenue, Southeast, Minneapolis, Hennepin County, MN

  4. 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

  5. Swimming Near the Wall

    NASA Astrophysics Data System (ADS)

    Quinn, Daniel; Moored, Keith; Dewey, Peter; Lauder, George; Smits, Alexander

    2012-11-01

    The aerodynamic loads on rectangular panels undergoing heave and pitch oscillations near a solid wall were measured using a 6-axis ATI sensor. Over a range of Strouhal numbers, reduced frequencies and flexibilities, swimming near the wall was found to increase thrust and therefore the self-propelled swimming speed. Experimental particle image velocimetry revealed an asymmetric wake structure with a momentum jet angled away from the wall. Both the thrust amplification and the asymmetric wake structure were verified and investigated further using an in-house inviscid panel method code. Supported by ONR MURI Grant N00014-08-1-0642.

  6. Flagellar propulsion near walls

    NASA Astrophysics Data System (ADS)

    Evans, Arthur; Lauga, Eric

    2010-11-01

    Confinement and wall effects are known to affect the kinematics and propulsive characteristics of swimming microorganisms. When a solid body is dragged through a viscous fluid at constant velocity, the presence of a wall increases fluid drag, and thus the net force required to maintain speed has to increase. In contrast, recent optical trapping experiments have revealed that the propulsive force generated by human spermatozoa is decreased by the presence of boundaries. Here we use simple models to analytically elucidate the propulsive effects of a solid boundary on passively actuated filaments and model eukaryotic flagella. We show that in some cases, the increase in fluid friction induced by the wall can lead to a change in the waveform expressed by the flagella which results in a decrease of their propulsive force near a no-slip wall.

  7. Anterior vaginal wall repair

    MedlinePlus

    ... your health care provider may have you learn pelvic floor muscle exercises ( Kegel exercises ), use estrogen cream in ... GM. Anatomic defects of the abdominal wall and pelvic floor: abdominal and inguinal hernias, cystocele, urethrocele, enterocele, rectocele, ...

  8. 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…

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.…

  14. 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.

  15. 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…

  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. 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

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 38. NORTHEAST ROOM, SECOND FLOOR, SOUTH WALL. ROOM COMPLETELY WALLED ...

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

    38. NORTHEAST ROOM, SECOND FLOOR, SOUTH WALL. ROOM COMPLETELY WALLED WITH RANDOM WIDTH BOARDS WHICH WERE PAPERED OR PLASTERED OVER. THIS WAS TYPICAL THROUGHOUT HOUSE EXCEPT FOR WOOD PANELED WALLS - John Mark Verdier House, 801 Bay & Scott Streets, Beaufort, Beaufort County, SC

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Geometric optics radome analysis wall incorporating effects of wall curvature

    NASA Astrophysics Data System (ADS)

    Kozakoff, Dennis J.

    1993-07-01

    In this research, a principal unmodeled error contributor in radome analysis is identified as the local plane approximation at the ray intercept point. An improved approach to modeling and computing the effects of the radome wall was developed which improves the radome wall transmission wall analysis in three respects: use of surface integration, utilization of a divergence factor (DF) to account for wall curvature, and incorporation of the effects of multiple refraction (MR). Modeling an incident plane wave on an external reference plane as an ensemble of Huygen's sources, geometric optics is used to trace the fields from the reference plane through the radome wall to a receiving monopulse antenna, where the wall transmissions on each ray are collected. The fact that the integration of a bundle of rays through the radome wall, as opposed to a single ray, more densely samples the curvature variation results in a more robust model. A DF derived from Snell's law for spherical shells accounts for the local wall curvature at the ray intercept point. To validate the approach, a microwave measurement setup was assembled around a network analyzer. Swept frequency data were obtained for similar monolithic wall dielectric panels but with different wall curvatures. Comparisons were then with measured data and the predictions of the model herein.

  13. Axions from wall decay

    SciTech Connect

    Chang, S; Hagmann, C; Sikivie, P

    2001-01-08

    The authors discuss the decay of axion walls bounded by strings and present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale of order the light travel time, and the average energy of the radiated axions is {approx_equal} 7m{sub a} for v{sub a}/m{sub a} {approx_equal} 500. is found to increase approximately linearly with ln(v{sub a}/m{sub a}). Extrapolation of this behavior yields {approx_equal} 60 m{sub a} in axion models of interest.

  14. Eye-wall resection.

    PubMed Central

    Char, D H; Miller, T; Crawford, J B

    2000-01-01

    PURPOSE: To review the ocular retention rates, visual results, and metastases in uveal tumors managed with eye-wall resection techniques. METHODS: This was a retrospective analysis of uveal tumors selected for eye-wall resection with the surgical procedures performed by a single surgeon. All enucleation specimens were reviewed by one author. Both parametric and non-parametric analysis of data was performed. RESULTS: A total of 132 eyes were scheduled for eye-wall resection surgery. Mean patient age was 52 years (range, 11 to 86 years). Tumors involved the iris alone in 17 cases, the iris-ciliary body in 53, the ciliary body alone in 16, and the choroid (ciliochoroidal, iris-ciliary body-choroid, or choroid) in 46 cases. A total of 114 eyes harbored melanomas; tumors located more posteriorly were more likely to have epithelioid cells (P < .05). Mean follow-up was 6 years. Mean number of clock hours in iris and iris-ciliary body tumors was 3.5. In tumors that involved the choroid, the mean largest diameter was 12.6 mm and the mean thickness was 8.2 mm. Ninety-three (70%) of 132 eyes were retained. Histologic assessment of surgical margins did not correlate with either evidence of tumor in enucleated eyes or metastatic disease. Surgical margins of tumors located more anteriorly were more likely to be clear on histologic evaluation (P < .05). Approximately 56% of retained eyes had a final visual acuity of 20/40 or better; visual results were significantly better in tumors located more anteriorly (P < .05). All retained eyes with iris tumors had a final visual acuity of 20/40 or better. In tumors that involved the choroid, 8 of 25 retained eyes kept visual acuity of 20/40 or better. Metastases developed in 8 patients; all metastatic events developed in patients with tumors that involved the choroid, and 7 of 8 were mixed cell melanomas. CONCLUSIONS: Seventy percent of eyes were retained, and 56% of these had a final visual acuity of 20/40 or better. Only 7% of patients

  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. Foucault pendulum ``wall clock''

    NASA Astrophysics Data System (ADS)

    Crane, H. Richard

    1995-01-01

    Details are given for the construction of a 70-cm-long Foucault pendulum to be mounted on the wall, and for a simple modification that will make it display local clock time. The possibility of having a Foucault pendulum of such short length is the result of finding new or improved ways of reducing four perturbing effects that become more severe as the length is decreased. They relate to: precession due to ellipticity in the motion, the drive system for maintaining the amplitude, the means of limiting the growth of ellipticity, and the method of gripping the suspending wire at the top. With those improvements, successful Foucault operation was attained in pendulums as short as 15 cm, support to center of bob. Following that severe test, the length for the ``wall clock'' was set at a conservative 70 cm. At that length it is highly reliable, and accurate to within 2% when timed for the full revolution. Uniformity in rate when comparing different intervals of azimuth is of course less. A simple method of making the pendulum read local time is described. Two clocks, one in the author's office and one at home, have been in continuous operation for more than ten years.

  17. Congenital lateral abdominal wall hernia.

    PubMed

    Montes-Tapia, Fernando; Cura-Esquivel, Idalia; Gutiérrez, Susana; Rodríguez-Balderrama, Isaías; de la O-Cavazos, Manuel

    2016-08-01

    Congenital abdominal wall defects that are located outside of the anterior wall are extremely rare and difficult to classify because there are no well accepted guidelines. There are two regions outside of the anterior wall: the flank or lateral wall; and the lumbar region. We report the case of a patient with an oval 3 cm-diameter hernia defect located above the anterior axillary line, which affects all layers of the muscular wall. An anorectal malformation consisting of a recto-vestibular fistula was also identified, and chest X-ray showed dextrocardia. The suggested treatment is repair of the defect before 1 year of age. Given that the anomalies described may accompany lateral abdominal wall hernia, it is important to diagnose and treat the associated defects.

  18. Dynamical domain wall and localization

    NASA Astrophysics Data System (ADS)

    Toyozato, Yuta; Higuchi, Masafumi; Nojiri, Shin'ichi

    2016-03-01

    Based on the previous works (Toyozato et al., 2013 [24]; Higuchi and Nojiri, 2014 [25]), we investigate the localization of the fields on the dynamical domain wall, where the four-dimensional FRW universe is realized on the domain wall in the five-dimensional space-time. Especially we show that the chiral spinor can localize on the domain wall, which has not been succeeded in the past works as the seminal work in George et al. (2009) [23].

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. Beyond the college walls.

    PubMed

    Healy, B P

    1992-03-01

    The author outlines historical and current reasons that the National Institutes of Health (NIH) and academic medicine are inherently political and are now facing expanding political exposure. She emphasizes especially the power of modern discoveries in biology; this power stems from the many practical benefits that these discoveries can bring and their economic implications, and the growing public awareness of these benefits and implications. She then discusses the political realities of the biomedical enterprise, illustrating them by describing the nature of issues surrounding (1) the NIH budget and (2) technology transfer. Discussion of the latter topic includes a detailed description of controversies about patents (which revolve around the issue of who owns and controls the distribution and use of scientific information) and several important policy issues that are raised by these controversies (e.g., should there be uniform international policies regarding intellectual property rights associated with discoveries of novel biologically expressed genes of uncertain in-vivo function, and if so, how is that achieved?). The author concludes by stating that these examples of the politics of knowledge and of the NIH are among many vital biomedical issues of American life (which she lists) that require the academic medicine community to look beyond its own walls and participate in the complex world of politics and public policy.

  10. 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.

  11. 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

  12. Wall Insulation; BTS Technology Fact Sheet

    SciTech Connect

    Southface Energy Institute; Tromly, K.

    2000-11-07

    Properly sealed, moisture-protected, and insulated walls help increase comfort, reduce noise, and save on energy costs. This fact sheet addresses these topics plus advanced framing techniques, insulation types, wall sheathings, and steps for effective wall construction and insulation.

  13. 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.

  14. 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

  15. Plant cell walls to ethanol.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. 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.

  17. Adaptive wall testing sections (AWTS)

    NASA Technical Reports Server (NTRS)

    Wolf, Stephen W. D.; Kilgore, Robert A.

    1987-01-01

    The lecture starts with conventional techniques of minimizing wall interference and explains the principle of wall streamlining. The history of AWTS development is highlighted, along with the benefits of wall streamlining, including minimized boundary interference, increased model size, reduced tunnel drive power, noise, and volume, as well as multiple flow field simulations to be performed using one test section. AWTS-associated problems coming from the need to adjust the test-section boundaries for each test condition are assessed, along with the requirements of a boundary-adjustment strategy. Examples of two- and three-dimensional test sections are presented, and attention is focused on residual interference and the effects of compressibility and model lift on flexible-wall contours.

  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. Functional domain walls in multiferroics

    NASA Astrophysics Data System (ADS)

    Meier, Dennis

    2015-11-01

    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.

  3. 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.

  4. Random vibration of compliant wall

    NASA Technical Reports Server (NTRS)

    Yang, J.-N.; Heller, R. A.

    1976-01-01

    The paper is concerned with the realistic case of two-dimensional random motion of a membrane with bending stiffness supported on a viscoelastic spring substrate and on an elastic base plate under both subsonic and supersonic boundary layer turbulence. The cross-power spectral density of surface displacements is solved in terms of design variables of the compliant wall - such as the dimensions and material properties of the membrane (Mylar), substrate (PVC foam), and panel (aluminum) - so that a sensitivity analysis can be made to examine the influence of each design variable on the surface response statistics. Three numerical examples typical of compliant wall design are worked out and their response statistics in relation to wave drag and roughness drag are assessed. The results can serve as a guideline for experimental investigation of the drag reduction concept through the use of a compliant wall.

  5. 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%.

  6. Dynamics of domain wall networks

    SciTech Connect

    Eto, Minoru; Fujimori, Toshiaki; Nagashima, Takayuki; Sakai, Norisuke; Nitta, Muneto; Ohashi, Keisuke

    2007-12-15

    Networks or webs of domain walls are admitted in Abelian or non-Abelian gauge theory coupled to fundamental Higgs fields with complex masses. We examine the dynamics of the domain wall loops by using the moduli approximation and find a phase rotation induces a repulsive force which can be understood as a Noether charge of Q-solitons. Non-Abelian gauge theory allows different types of loops which can be deformed to each other by changing a modulus. This admits the moduli geometry like a sandglass made by gluing the tips of the two cigar-(cone-)like metrics of a single triangle loop. We conclude that the sizes of all loops tend to grow for a late time in general models with complex Higgs masses, while the sizes are stabilized at some values once triplet masses are introduced for the Higgs fields. We also show that the stationary motion on the moduli space of the domain wall webs represents 1/4 Bogomol'nyi-Prasad-Sommerfield Q-webs of walls.

  7. 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…

  8. 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…

  9. 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)

  10. 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)

  11. 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.

  12. 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…

  13. 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

  14. Wall conditioning of JET with the ITER-Like Wall

    NASA Astrophysics Data System (ADS)

    Douai, D.; Brezinsek, S.; Esser, H. G.; Joffrin, E.; Keenan, T.; Knipe, S.; Kogut, D.; Lomas, P. J.; Marsen, S.; Nunes, I.; Philipps, V.; Pitts, R. A.; Shimada, M.; de Vries, P.; JET EFDA Contributors

    2013-07-01

    The initial conditioning cycle of JET ILW is analysed and compared with restart and operation in 2008 with a carbon dominated wall. Comparable water and oxygen decay times are observed during bake-out in both cases. Despite a 2 × 10-3 mbar l/s leak rate during plasma operation, no further wall conditioning has been necessary after plasma restart in ILW, which dramatically contrasts with 2008. Plasma O content is lower with the ILW. Higher O levels are measured after nights or week-ends, BeO layers being formed and re-eroded, but do not impact plasma operation and performance. First results on isotopic wall changeover by GDC on the ILW six months of the first D2 campaign evidence a reservoir of about 3 × 1022 atoms, i.e. ten time lower than in carbon PFCs. A study in JET of the glow discharge current distribution for different ratios of the ionization mean free paths to the vessel dimensions seems to indicate sufficient toroidal and poloidal homogeneity in ITER.

  15. 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

  16. Actinomycosis involving the chest wall: CT findings

    SciTech Connect

    Webb, W.R.; Sagel, S.S.

    1982-11-01

    Two cases of pulmonary actinomycosis with extension to involve the chest wall that were evaluated using computerized tomography are reported. In both cases, the relation of pulmonary and chest wall disease was best shown using CT. (KRM)

  17. 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.

  18. Walled-off pancreatic necrosis.

    PubMed

    Ramia, J M; de la Plaza, R; Quiñones-Sampedro, J E; Ramiro, C; Veguillas, P; García-Parreño, J

    2012-05-01

    Acute severe pancreatitits may be complicated by the development of 'walled-off pancreatic necrosis' (WOPN), which is characterised by a mixture of solid components and fluids on imaging studies as a consequence of organised pancreatic tissue necrosis. We present here an overview of the definition, clinical features, and diagnostic and therapeutic management of this clinical condition, which is mostly based on consensus as adequate clinical trials are lacking. PMID:22641624

  19. Wall slip in polymer melts

    NASA Astrophysics Data System (ADS)

    Léger, L.; Hervet, H.; Massey, G.; Durliat, E.

    1997-09-01

    We present a review of the recent characterizations of the flow behaviour of high-molecular-weight polymer melts, with special emphasis on situations in which slip at the wall appears. These characterizations are based on direct measurements of the local velocity of the fluid, in the immediate vicinity of the solid wall, through near-field velocimetry techniques. The results demonstrate the importance of polymer molecules anchored on the solid surface, either by strong adsorption or by chemical grafting, and entangled with the bulk polymer, to produce a strong friction at low shear rates and to lead to a shear rate threshold above which strong slip at the wall and low friction develop. The evolution of the shear rate threshold and of the flow characteristics (the length of the extrapolation of the velocity profile to zero, the critical slip velocity for the onset of strong slip, ...) with the molecular parameters of the system (the molecular weights of the bulk and surface chains, and the surface density of anchored chains) is analysed and compared with the predictions of recent theoretical models.

  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. 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.

  2. 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.

  3. 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).

  4. 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.

  5. 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.

  6. Gas enrichment at liquid-wall interfaces.

    PubMed

    Dammer, Stephan M; Lohse, Detlef

    2006-05-26

    Molecular dynamics simulations of Lennard-Jones systems are performed to study the effects of dissolved gas on liquid-wall and liquid-gas interfaces. Gas enrichment at walls, which for hydrophobic walls can exceed more than 2 orders of magnitude when compared to the gas density in the bulk liquid, is observed. As a consequence, the liquid structure close to the wall is considerably modified, leading to an enhanced wall slip. At liquid-gas interfaces gas enrichment which reduces the surface tension is found.

  7. Major chest wall reconstruction after chest wall irradiation

    SciTech Connect

    Larson, D.L.; McMurtrey, M.J.; Howe, H.J.; Irish, C.E.

    1982-03-15

    In the last year, 12 patients have undergone extensive chest wall resection. Eight patients had recurrent cancer after prior resection and irradiation with an average defect of 160 square centimeters, usually including ribs and a portion of the sternum; four had radionecrosis of soft tissue and/or bone. Methods of reconstruction included latissimus dorsi musculocutaneous (MC) flap (five patients), pectoralis major MC flap (seven patients), and omental flap and skin graft (one patient). The donor site was usually closed primarily. All flaps survived providing good wound coverage. The only complication was partial loss of a latissimus dorsi MC flap related to an infected wound; this reconstruction was salvaged with a pectoralis major MC flap. The hospital stay ranged from 10-25 days with a median stay of 11 days. Use of the MC flap is a valuable tool which can be used to significantly decrease morbidity, hospital stay, and patient discomfort related to the difficult problem of chest wall reconstruction after radiation therapy.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Tevatron Resistive Wall Current Monitor

    SciTech Connect

    Crisp, J.; Fellenz, B.; /Fermilab

    2011-01-01

    Resistive Wall Current Monitors (RWCM) were designed and built for the Fermilab Tevatron (Tev) project. These devices measure longitudinal beam current from 3 KHz to 6 GHz with 1.34 ohm gap impedance. There are two RWCM's installed a few feet apart in the Tevatron, upstream RWCM is used for general purpose use, downstream RWCM is dedicated for longitudinal parameters of coalesced beam bunches and bunch intensities. The design provides a calibration or test port for injecting test signals. Microwave absorber material is used to reduce interference from spurious electromagnetic waves traveling inside the beam pipe. This paper will do an overview how the RWCM was designed and its test results.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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...

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Hydrodynamics of ultra-relativistic bubble walls

    NASA Astrophysics Data System (ADS)

    Leitao, Leonardo; Mégevand, Ariel

    2016-04-01

    In cosmological first-order phase transitions, gravitational waves are generated by the collisions of bubble walls and by the bulk motions caused in the fluid. A sizeable signal may result from fast-moving walls. In this work we study the hydrodynamics associated to the fastest propagation modes, namely, ultra-relativistic detonations and runaway solutions. We compute the energy injected by the phase transition into the fluid and the energy which accumulates in the bubble walls. We provide analytic approximations and fits as functions of the net force acting on the wall, which can be readily evaluated for specific models. We also study the back-reaction of hydrodynamics on the wall motion, and we discuss the extrapolation of the friction force away from the ultra-relativistic limit. We use these results to estimate the gravitational wave signal from detonations and runaway walls.

  6. Polyamines in cell walls of chlorococcalean microalgae.

    PubMed

    Burczyk, Jan; Zych, Maria; Ioannidis, Nikolaos E; Kotzabasis, Kiriakos

    2014-01-01

    Biotechnology of microalgae represents a very attractive alternative as a source of energy and substances of high value when compared with plant cultivation. Cell walls of green microalgae have an extraordinary chemical and mechanical resistance and may impede some steps in the biotechnological/industrial exploitation of algae. The aim of the present contribution was to check the presence of polyamines in the cell walls of chlorococcalean green microalgae. Polyamines are nitrogenous compounds synthesized normally in cells and may affect the properties of the cell wall. Our work included strains either forming or not forming the polymer algaenan, allowing us to conclude that algaenan is not a prerequisite for the presence of polyamines in the cell walls. Polyamines were detected in isolated cell walls of Scenedesmus obliquus, Chlorella fusca, Chlorella saccharophila, and Chlorella vulgaris. Their concentration in isolated cell walls ranged between 0.4 and 8.4 nmol/mg dry weight. PMID:24772826

  7. 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.

  8. Vapor wall deposition in Teflon chambers

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Schwantes, R. H.; McVay, R. C.; Lignell, H.; Coggon, M. M.; Flagan, R. C.; Seinfeld, J. H.

    2015-04-01

    Teflon chambers are ubiquitous in studies of atmospheric chemistry. Secondary organic aerosol (SOA) formation can be underestimated, owing to deposition of SOA-forming vapors to the chamber wall. We present here an experimental protocol and a model framework to constrain the vapor-wall interactions in Teflon chambers. We measured the wall deposition rates of 25 oxidized organic compounds generated from the photooxidation of isoprene, toluene, α-pinene, and dodecane in two chambers that had been extensively used and in two new unused chambers. We found that the extent of prior use of the chamber did not significantly affect the sorption behavior of the Teflon films. Among the 25 compounds studied, the maximum wall deposition rate is exhibited by the most highly oxygenated and least volatile compounds. By optimizing the model output to the observed vapor decay profiles, we identified that the dominant parameter governing the extent of wall deposition of a compound is its wall accommodation coefficient (αwi), which can be correlated through its volatility with the number of carbons and oxygens in the molecule. By doing so, the wall-induced deposition rate of intermediate/semi-volatile organic vapors can be reasonably predicted based on their molecular constituency. The extent to which vapor wall deposition impacts measured SOA yields depends on the competition between uptake of organic vapors by suspended particles and the chamber wall. The timescale associated with vapor wall deposition can vary from minutes to hours depending on the value of αw,i. For volatile and intermediate volatility organic compounds (small αw,i), gas-particle partitioning will dominate wall deposition for typical particle number concentrations in chamber experiments. For compounds characterized by relatively large αw,i, vapor transport to particles is suppressed by competition with the chamber wall even with perfect particle accommodation.

  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. 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.

  11. [FUNCTIONAL PLASTIC OF ANTERIOR ABDOMINAL WALL HERNIAS].

    PubMed

    Grubnik, V V; Parfentyeva, N D; Parfentyev, R S

    2015-07-01

    In order to improve the treatment efficacy of postoperative anterior abdominal wall hernias the method of plastic with restoration of anatomical and physiological properties of the muscles of the anterior abdominal wall was used. After the intervention by the improved method, regardless of the location of the hernia defect yielded promising results for the conservation of anterior abdominal wall muscle function in 75% of cases completely restored functional ability of muscles recti abdomini. PMID:26591212

  12. Panelized wall system with foam core insulation

    DOEpatents

    Kosny, Jan; Gaskin, Sally

    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.

  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). PMID:22329798

  14. 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.

  15. 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.

  16. Creating universes with thick walls

    NASA Astrophysics Data System (ADS)

    Ulvestad, Andrew; Albrecht, Andreas

    2012-05-01

    We study the dynamics of a spherically symmetric false vacuum bubble embedded in a true vacuum region separated by a “thick wall”, which is generated by a scalar field in a quartic potential. We study the “Farhi-Guth-Guven” (FGG) quantum tunneling process by constructing numerical solutions relevant to this process. The Arnowitt-Deser-Misner mass of the spacetime is calculated, and we show that there is a lower bound that is a significant fraction of the scalar field mass. We argue that the zero mass solutions used to by some to argue against the physicality of the FGG process are artifacts of the thin wall approximation used in earlier work. We argue that the zero mass solutions should not be used to question the viability of the FGG process.

  17. 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.

  18. 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).

  19. Structure of Plant Cell Walls

    PubMed Central

    Weinstein, Larry; Albersheim, Peter

    1979-01-01

    Wild type Bacillus subtilis, when grown on beet araban, secretes into its culture medium an endo-arabanase and two arabinosidases. An alternate procedure to one previously described (Kaji A, T Saheki 1975 Biochim Biophys Acta 410: 354-360) has been developed for the purification of the endo-arabanase. The purified endo-arabanase is shown to be homogeneous by sodium dodecyl sulfate-urea disc gel electrophoresis (molecular weight ≃ 32,000) and by isoelectric focusing (pI = 9.3). The endo-arabanase, acting on a branched araban substrate, has maximal activity at pH 6.0 and preferentially cleaves 5-linked arabinosyl residues. One of the arabinosidases (molecular weight ≃ 65,000, pI = 5.3) has been purified to the point that it contains only one quantitatively minor contaminant, as shown by sodium dodecyl sulfate-urea disc gel electrophoresis and isoelectric focusing. The purified arabinosidase, acting on p-nitrophenyl-α-l-arabinofuranoside, has maximal activity at pH 6.5, and, when acting on a branched araban substrate, preferentially attacks nonreducing terminal arabinosyl residues linked to the 2 or 3 position of other arabinosyl residues. Neither of the two purified enzymes is capable of hydrolyzing a variety of carbohydrate substrates which lack arabinosidic linkages. The purified endo-arabinase is shown to be capable of releasing arabinosyl oligomers from the walls of suspension-cultured sycamore cells, thereby suggesting its usefulness as a probe in studying the structure of the araban component of primary cell walls. PMID:16660741

  20. 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.

  1. 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.

  2. 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.

  3. Molecular regulation of plant cell wall extensibility.

    PubMed

    Cosgrove, D J

    1998-05-01

    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. PMID:11540640

  4. Chest wall angiolipoma complicating von Recklinghausen disease.

    PubMed

    Komatsu, Teruya; Takahashi, Koji; Fujinaga, Takuji

    2013-09-01

    We present the case of an 18-year-old man with chest wall angiolipoma and a medical history of von Recklinghausen neurofibromatosis. The chest wall tumor was originally detected during an evaluation for chest pain. For diagnostic and therapeutic purposes, video-assisted thoracoscopic resection was performed, and the tumor was histopathologically confirmed to be an angiolipoma. Chest wall angiolipoma is exceptionally rare. Only two cases have been reported in the English literature, with no reports regarding chest wall angiolipoma in a patient with von Recklinghausen disease.

  5. 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/.

  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. Low-rise shear wall failure modes

    SciTech Connect

    Farrar, C.R. ); Hashimoto, P.S. ); Reed, J.W. and Associates, Inc., Mountain View, CA )

    1991-01-01

    A summary of the data that are available concerning the structural response of low-rise shear walls is presented. This data will be used to address two failure modes associated with the shear wall structures. First, data concerning the seismic capacity of the shear walls with emphasis on excessive deformations that can cause equipment failure are examined. Second, data concerning the dynamic properties of shear walls (stiffness and damping) that are necessary to compute the seismic inputs to attached equipment are summarized. This case addresses the failure of equipment when the structure remains functional. 23 refs.

  8. 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.

  9. 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.

  10. 5. 'Stones for Wing Walls, Tunnel Walls, BeltCourse and Coping,' ...

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

    5. 'Stones for Wing Walls, Tunnel Walls, Belt-Course and Coping,' Southern Pacific Standard Plan Tunnels, ca. 1909. - Central Pacific Transcontinental Railroad, Sacramento to Nevada state line, Sacramento, Sacramento County, CA

  11. 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

  12. Calculation of wall effects of flow on a perforated wall with a code of surface singularities

    NASA Astrophysics Data System (ADS)

    Piat, J. F.

    1994-07-01

    Simplifying assumptions are inherent in the analytic method previously used for the determination of wall interferences on a model in a wind tunnel. To eliminate these assumptions, a new code based on the vortex lattice method was developed. It is suitable for processing any shape of test sections with limited areas of porous wall, the characteristic of which can be nonlinear. Calculation of wall effects in S3MA wind tunnel, whose test section is rectangular 0.78 m x 0.56 m, and fitted with two or four perforated walls, have been performed. Wall porosity factors have been adjusted to obtain the best fit between measured and computed pressure distributions on the test section walls. The code was checked by measuring nearly equal drag coefficients for a model tested in S3MA wind tunnel (after wall corrections) and in S2MA wind tunnel whose test section is seven times larger (negligible wall corrections).

  13. Interconnections between cell wall polymers, wall mechanics, and cortical microtubules: Teasing out causes and consequences.

    PubMed

    Xiao, Chaowen; Anderson, Charles T

    2016-09-01

    In plants, cell wall components including cellulose, hemicelluloses, and pectins interact with each other to form complex extracellular network structures that control cell growth and maintain cell shape. However, it is still not clear exactly how different wall polymers interact, how the conformations and interactions of cell wall polymers relate to wall mechanics, and how these factors impinge on intracellular structures such as the cortical microtubule cytoskeleton. Here, based on studies of Arabidopsis thaliana xxt1 xxt2 mutants, which lack detectable xyloglucan in their walls and display aberrant wall mechanics, altered cellulose patterning and biosynthesis, and reduced cortical microtubule stability, we discuss the potential relationships between cell wall biosynthesis, wall mechanics, and cytoskeletal dynamics in an effort to better understand their roles in controlling plant growth and morphogenesis. PMID:27611066

  14. Interconnections between cell wall polymers, wall mechanics, and cortical microtubules: Teasing out causes and consequences.

    PubMed

    Xiao, Chaowen; Anderson, Charles T

    2016-09-01

    In plants, cell wall components including cellulose, hemicelluloses, and pectins interact with each other to form complex extracellular network structures that control cell growth and maintain cell shape. However, it is still not clear exactly how different wall polymers interact, how the conformations and interactions of cell wall polymers relate to wall mechanics, and how these factors impinge on intracellular structures such as the cortical microtubule cytoskeleton. Here, based on studies of Arabidopsis thaliana xxt1 xxt2 mutants, which lack detectable xyloglucan in their walls and display aberrant wall mechanics, altered cellulose patterning and biosynthesis, and reduced cortical microtubule stability, we discuss the potential relationships between cell wall biosynthesis, wall mechanics, and cytoskeletal dynamics in an effort to better understand their roles in controlling plant growth and morphogenesis.

  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 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.

  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 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.

  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. 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.

  1. Moduli of monopole walls and amoebas

    NASA Astrophysics Data System (ADS)

    Cherkis, Sergey A.; Ward, Richard S.

    2012-05-01

    We study doubly-periodic monopoles, also called monopole walls, determining their spectral data and computing the dimensions of their moduli spaces. Using spectral data we identify the moduli, and compare our results with a perturbative analysis. We also identify an SL(2, {Z}) action on monopole walls, in which the S transformation corresponds to the Nahm transform.

  2. Dzyaloshinskii-Moriya Domain Walls in Nanotubes

    NASA Astrophysics Data System (ADS)

    Tretiakov, Oleg; Goussev, Arseni; Robbins, J. M.; Slastikov, Valeriy

    2015-03-01

    We study domain walls in thin ferromagnetic nanotubes with Dzyaloshinskii-Moriya interaction (DMI). Dramatic effects arise from the interplay of space curvature and spin-orbit induced DMI on the domain wall structure in these systems. The domain walls become narrower in systems with DMI and curvature. Moreover, the domain walls created in such nanotubes can propagate without Walker breakdown for arbitrary applied currents, thus allowing for a robust and controlled domain-wall motion. The domain-wall velocity is directly proportional to the non-adiabatic spin transfer torque current term and is insensitive to the adiabatic current term. Application of an external magnetic field along the nanotube axis triggers rich dynamical response of the curved domain wall. In particular, we show that the propagation velocity is a non-linear function of both the applied field and DMI, and strongly depends on the orientation and chirality of the wall. We acknowledge support by the Grants-in-Aid for Scientific Research (No. 25800184 and No. 25247056) from the MEXT, Japan and SpinNet.

  3. 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.

  4. 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 challenge/growth…

  5. 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.

  6. 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?

  7. 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 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.245 Fire walls. Each...

  8. 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...

  9. 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...

  10. 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...

  11. 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..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.245 Fire walls. Each...

  12. Mechanics of the Toxoplasma gondii oocyst wall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. 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…

  14. 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.

  15. Interactive Word Walls: Transforming Content Vocabulary Instruction

    ERIC Educational Resources Information Center

    Jackson, Julie; Tripp, Sherry; Cox, Kimberly

    2011-01-01

    Word walls are designed to serve as visual scaffolds and are a common classroom tool used to support reading and language arts instruction. To support vocabulary development in science and support students who are ELLs, Husty and Jackson (2008) created interactive word walls that resemble semantic maps (Masters, Mori, and Mori 1993). Semantic maps…

  16. Drag reduction at a plane wall

    NASA Technical Reports Server (NTRS)

    Hill, D. C.

    1993-01-01

    The objective is to determine by analytical means how drag on a plane wall may be modified favorably using a minimal amount of flow information - preferably only information at the wall. What quantities should be measured? How should that information be assimilated in order to arrive at effective control? As a prototypical problem, incompressible, viscous flow, governed by the Navier-Stokes equations, past a plane wall at which the no-slip condition was modified was considered. The streamwise and spanwise velocity components are required to be zero, but the normal component is to be specified according to some control law. The challenge is to choose the wall-normal velocity component based on flow conditions at the wall so that the mean drag is as small as possible. There can be no net mass flux through the wall, and the total available control energy is constrained. A turbulent flow is highly unsteady and has detailed spatial structure. The mean drag on the wall is the integral over the wall of the local shear forces exerted by the fluid, which is then averaged in time; it is a 'macroscopic' property of the flow. It is not obvious how unsteady boundary control is to be applied in order to modify the mean flow most effectively, especially in view of the non- self-adjoint nature of the governing equations. An approximate analytical solution to the suboptimal scheme is pursued.

  17. Reduced order modeling of wall turbulence

    NASA Astrophysics Data System (ADS)

    Moin, Parviz

    2015-11-01

    Modeling turbulent flow near a wall is a pacing item in computational fluid dynamics for aerospace applications and geophysical flows. Gradual progress has been made in statistical modeling of near wall turbulence using the Reynolds averaged equations of motion, an area of research where John Lumley has made numerous seminal contributions. More recently, Lumley and co-workers pioneered dynamical systems modeling of near wall turbulence, and demonstrated that the experimentally observed turbulence dynamics can be predicted using low dimensional dynamical systems. The discovery of minimal flow unit provides further evidence that the near wall turbulence is amenable to reduced order modeling. The underlying rationale for potential success in using low dimensional dynamical systems theory is based on the fact that the Reynolds number is low in close proximity to the wall. Presumably for the same reason, low dimensional models are expected to be successful in modeling of the laminar/turbulence transition region. This has been shown recently using dynamic mode decomposition. Furthermore, it is shown that the near wall flow structure and statistics in the late and non-linear transition region is strikingly similar to that in higher Reynolds number fully developed turbulence. In this presentation, I will argue that the accumulated evidence suggests that wall modeling for LES using low dimensional dynamical systems is a profitable avenue to pursue. The main challenge would be the numerical integration of such wall models in LES methodology.

  18. Revisiting the Ladder on a Wall Problem

    NASA Astrophysics Data System (ADS)

    Salu, Yehuda

    2011-05-01

    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.1-4 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 walls. This is also how the situation is presented in most textbooks. One may get the impression that the friction between a ladder and a wall is always negligible, or that dealing with it is so difficult that it should be left out of the realm of introductory physics. The truth of the matter is that the magnitude of the friction coefficient between a ladder and a wall is not much different from that with the floor, and that friction with the wall is an important part of the conditions for having a static ladder. This paper derives a simple relationship between the friction coefficients of the ladder with the floor (μ1) and with the wall (μ2), when the ladder is in static equilibrium. Figure 1 shows the forces that act on a ladder that leans on a wall.

  19. 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.

  20. Natural Paradigms of Plant Cell Wall Degradation

    SciTech Connect

    Wei, H.; Xu, Q.; Taylor, L. E.; Baker, J. O.; Tucker, M. P.; Ding, S. Y.

    2009-01-01

    Natural processes of recycling carbon from plant cell walls are slow but very efficient, generally involving microbial communities and their secreted enzymes. Efficient combinations of microbial communities and enzymes act in a sequential and synergistic manner to degrade plant cell walls. Recent understanding of plant cell wall ultra-structure, as well as the carbon metabolism, ATP production, and ecology of participating microbial communities, and the biochemical properties of their cellulolytic enzymes have led to new perspectives on saccharification of biomass. Microbial communities are dynamic functions of the chemical and structural compositions of plant cell wall components. The primitive 'multicellularity' exhibited by certain cellulolytic microorganisms may play a role in facilitating cell-cell communication and cell-plant cell wall-substrate interaction.

  1. 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.

  2. An NPARC Turbulence Module with Wall Functions

    NASA Technical Reports Server (NTRS)

    Zhu, J.; Shih, T.-H.

    1997-01-01

    The turbulence module recently developed for the NPARC code has been extended to include wall functions. The Van Driest transformation is used so that the wall functions can be applied to both incompressible and compressible flows. The module is equipped with three two-equation K-epsilon turbulence models: Chien, Shih-Lumley and CMOTR models. Details of the wall functions as well as their numerical implementation are reported. It is shown that the inappropriate artificial viscosity in the near-wall region has a big influence on the solution of the wall function approach. A simple way to eliminate this influence is proposed, which gives satisfactory results during the code validation. The module can be easily linked to the NPARC code for practical applications.

  3. 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%.

  4. Vapor wall deposition in Teflon chambers

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Schwantes, R. H.; McVay, R. C.; Lignell, H.; Coggon, M. M.; Flagan, R. C.; Seinfeld, J. H.

    2014-10-01

    Teflon chambers are ubiquitous in studies of atmospheric chemistry. Secondary organic aerosol (SOA) formation can be substantially underestimated owing to deposition of SOA-forming compounds to chamber walls. We present here an experimental protocol to constrain the nature of wall deposition of organic vapors in Teflon chambers. We measured the wall deposition rates of 25 oxidized organic compounds generated from the photooxidation of isoprene, toluene, α-pinene, and dodecane in two chambers that had been extensively used and in two new unused chambers. We found that the extent of prior use of the chamber did not significantly affect the sorption behavior of the Teflon films. The dominant parameter governing the extent of wall deposition of a compound is its wall accommodation coefficient (αw,i), which can be correlated through its volatility (Ci*) with the number of carbons (nC) and oxygens (nO) in the molecule. Among the 25 compounds studied, the maximum wall deposition rate is approached by the most highly oxygenated and least volatile compounds. The extent to which vapor wall deposition impacts measured SOA yields depends on the competition between uptake of organic vapors by suspended particles and chamber walls. Gas-particle equilibrium partitioning is established relatively rapidly in the presence of perfect accommodation of organic vapors onto particles or when a sufficiently large concentration of suspended particles is present. The timescale associated with vapor wall deposition can vary from minutes to hours depending on the value of αw,i. For volatile and intermediate volatility organic compounds (small αw,i), gas-particle partitioning will be dominant for typical particle number concentrations in chamber experiments. For large αw,i, vapor transport to particles is suppressed by competition with the chamber walls even with perfect particle accommodation.

  5. Wall induced turbulence distortions of optical measurements

    NASA Astrophysics Data System (ADS)

    Gustafsson, Ove K. S.; Henriksson, Markus; Sjöqvist, Lars

    2009-09-01

    Optical measurements and tests of optical instruments are often performed through an opened window or from the roof of an elevated building. This can also be a common situation for free-space optical (FSO) communication systems. Wind friction in combination with solar heating of the wall and the ground will create increased turbulence in a boundary layer close to the wall. For an outgoing laser beam this thin region of strong turbulence causes beam wander, beam broadening and beam break-up. For imaging and detection systems angle of arrival fluctuations and image blurring may result. In an attempt to estimate the strength of the atmospheric turbulence in the layer at the wall the refractive index structure constant (Cn2) was measured with an ultra sonic anemometer as a function of distance from the wall. The measurements were performed at the lower part of a window that was open just enough to give space for the anemometer. The window was placed 10 m above ground in a 12 m high building, with brick wall below the window and wooden panel above the window. Measurements of the turbulence as a function of distance from the wall were performed during different times of the day to study the influence of sun heating of the wall. The measured average Cn2 shows an exponentially decreasing function of distance from the wall. The exponential decay of Cn2 depends on the time of the day. The highest measured value of Cn2 was approximately 3x10-11 m-2/3 near the wall. The influence of wall turbulence is discussed with respect to its influence on laser beam propagation.

  6. 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.

  7. 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.

  8. Cell wall of Fusarium sulphureum; I. Chemical composition of the hyphal wall.

    PubMed

    Barran, L R; Schneider, E F; Wood, P J; Madhosingh, C; Miller, R W

    1975-05-01

    The hyphae wall of Fusarium sulphureum Schlect. (Isolate 1) was isolated and purified. Electron microscopy studies showed that the isolated cell wall consisted of two distinct layers, an outer electron dense layer and a broader electron transparent inner layer. Chemical analysis revealed that the cell wall contained 66% carbohydrate, 7.3% protein, 5.5% lipid and 1.8% ash. The major cell wall component N-acetylglucosamine (39%) was shown by X-ray diffraction analysis to be present as chitin. Glucose constituted 14% of the cell wall, while mannose, galactose, and glucuronic acid, accounted for 15% of the cell wall. Glucuronic acid appears to be predominantly linked to galactose in the intact wall.

  9. 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.

  10. Dynamic response of cantilever retaining walls

    SciTech Connect

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

    1996-10-01

    A critical evaluation is made of the response to horizontal ground shaking of flexible cantilever retaining walls that are elastically constrained against rotation at their base. The retained medium is idealized as a uniform, linear, viscoelastic stratum of constant thickness and semi-infinite extent in the horizontal direction. The parameters varied include the flexibilities of the wall and its base, the properties of the retained medium, and the characteristics of the ground motion. In addition to long-period, effectively static excitations, both harmonic base motions and an actual earthquake record are considered. The response quantities examined include the displacements of the wall relative to the moving base, the wall pressures, and the associated shears and bending moments. The method of analysis employed is described only briefly, emphasis being placed on the presentation and interpretation of the comprehensive numerical solutions. It is shown that, for realistic wall flexibilities, the maximum wall forces are significantly lower than those obtained for fixed-based rigid walls and potentially of the same order of magnitude as those computed by the Mononobe-Okabe method.

  11. Domain Wall structures in wide permalloy strips

    NASA Astrophysics Data System (ADS)

    Estevez, Virginia; Laurson, Lasse

    2015-03-01

    We analyze numerically the equilibrium micromagnetic domain wall structures encountered in Permalloy strips of a wide range of thicknesses and widths, with strip widths up to several micrometers. By performing an extensive set of micromagnetic simulations, we show that the equilibrium phase diagram of the domain wall structures exhibits in addition to the previously found structures (symmetric and asymmetric transverse wall and vortex wall) also a double-vortex domain wall for large enough strip widths and thicknesses. In general, shape anisotropy is less important for wider strips, and thus energy minima with more complex spin structures closing the flux more efficiently than those found before for narrow strips may appear. Also several metastable domain wall structures are found, such as structures with three or four vortices or two vortices and an antivortex. We discuss the details of the relaxation process, including the effect of varying the magnitude of the Gilbert damping constant, and the role of using different initial conditions. Finally, we also consider the field-driven dynamics of the double-vortex domain wall.

  12. 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.

  13. Domain wall geometry controls conduction in ferroelectrics.

    PubMed

    Vasudevan, R K; Morozovska, A N; Eliseev, E A; Britson, J; Yang, J-C; Chu, Y-H; Maksymovych, P; Chen, L Q; Nagarajan, V; Kalinin, S V

    2012-11-14

    A new paradigm of domain wall nanoelectronics has emerged recently, in which the domain wall in a ferroic is itself an active device element. The ability to spatially modulate the ferroic order parameter within a single domain wall allows the physical properties to be tailored at will and hence opens vastly unexplored device possibilities. Here, we demonstrate via ambient and ultrahigh-vacuum (UHV) scanning probe microscopy (SPM) measurements in bismuth ferrite that the conductivity of the domain walls can be modulated by up to 500% in the spatial dimension as a function of domain wall curvature. Landau-Ginzburg-Devonshire calculations reveal the conduction is a result of carriers or vacancies migrating to neutralize the charge at the formed interface. Phase-field modeling indicates that anisotropic potential distributions can occur even for initially uncharged walls, from polarization dynamics mediated by elastic effects. These results are the first proof of concept for modulation of charge as a function of domain wall geometry by a proximal probe, thereby expanding potential applications for oxide ferroics in future nanoscale electronics. PMID:22994244

  14. 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.

  15. 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.

  16. 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.

  17. Heterogeneity of Left Ventricular Wall Thickening Mechanisms

    PubMed Central

    Cheng, Allen; Nguyen, Tom C.; Malinowski, Marcin; Daughters, George T.; Miller, D. Craig; Ingels, Neil B.

    2009-01-01

    Background: Myocardial fibers are grouped into lamina (or sheets) 3-4 cells thick. Fiber shortening produces systolic LV wall thickening primarily by laminar extension, thickening and shear, but the regional variability and transmural distribution of these three mechanisms are incompletely understood. Methods and Results: Nine sheep had transmural radiopaque markers inserted into the anterior basal and lateral equatorial LV. 4D marker dynamics were studied with biplane videofluoroscopy to measure circumferential, longitudinal, and radial systolic strains in the epicardium, midwall, and endocardium. Fiber and sheet angles from quantitative histology allowed transformation of these strains into transmural contributions of sheet extension, thickening, and shear to systolic wall thickening. At all depths, systolic wall thickening in the anterior basal region was 1.6-1.9 times that in the lateral equatorial region. Interestingly, however, systolic fiber shortening was identical at each transmural depth in these regions. Endocardial anterior basal sheet thickening were >2x greater than in the lateral equatorial region (epicardium: 0.16±0.15 vs. 0.03±0.06; endocardium: 0.45±0.40 vs. 0.17±0.09). Midwall sheet extension was >2x that in the lateral wall (0.22±0.12 vs. 0.09±0.06). Epicardial and midwall sheet shears in the anterior wall were ∼2x higher than in the lateral wall (epicardium: 0.14±0.07 vs. 0.05±0.03; midwall: 0.21±0.12 vs. 0.12±0.06). Conclusions: These data demonstrate fundamentally different regional contributions of laminar mechanisms for amplifying fiber shortening to systolic wall thickening. Systolic fiber shortening was identical at each transmural depth in both the anterior and lateral LV sites. However, systolic wall thickening of the anterior site was much greater than that of the lateral site. Fiber shortening drives systolic wall thickening, but sheet dynamics and orientations are of great importance to systolic wall thickening. LV wall

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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. PMID:26356964

  4. 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.

  5. Genetics Home Reference: abdominal wall defect

    MedlinePlus

    ... size and can usually be diagnosed early in fetal development, typically between the tenth and fourteenth weeks of ... organs at the abdominal wall opening late in fetal development may also contribute to organ injury. Intestinal damage ...

  6. 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)

  7. 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

  8. 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.

  9. Intercostal hemangioma of the chest wall

    PubMed Central

    Hamzík, Julian

    2016-01-01

    The authors describe a case of a 36-year-old patient who had six months’ pain of the thoracic spine and left chest. A soft slowly growing resistance was present on the dorso-lateral side of the left chest wall, in the range of the seventh to ninth rib. According to the medical history, the patient did not have any prior trauma and malignancy. A well-defined tumor of the left chest wall with calcifications, which grew to the seventh and eighth intercostal space, was present on computed tomography (CT) and magnetic resonance (MR) scans. The patient underwent resection of the tumor with the chest wall and reconstruction with polypropylene mesh. Histologically, it was a venous hemangioma, one of very rare tumors of the chest wall. PMID:27212983

  10. Axions from cosmic string and wall decay

    SciTech Connect

    Hagmann, Chris

    2010-08-30

    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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. The Structure of Plant Cell Walls

    PubMed Central

    Bauer, Wolfgang D.; Talmadge, Kenneth W.; Keegstra, Kenneth; Albersheim, Peter

    1973-01-01

    The molecular structure, chemical properties, and biological function of the xyloglucan polysaccharide isolated from cell walls of suspension-cultured sycamore (Acer pseudoplatanus) cells are described. The sycamore wall xyloglucan is compared to the extracellular xyloglucan secreted by suspension-cultured sycamore cells into their culture medium and is also compared to the seed “amyloid” xyloglucans. Xyloglucan—or fragments of xyloglucan—and acidic fragments of the pectic polysaccharides are released from endopolygalacturonase-pretreated sycamore walls by treatment of these walls with 8 m urea, endoglucanase, or 0.5 n NaOH. Some of the xyloglucan thus released is found to cochromatograph with the acidic pectic fragments on diethylaminoethyl Sephadex. The chemical or enzymic treatments required for the release of xyloglucan from the walls and the cochromatography of xyloglucan with the acidic pectic fragments indicate that xyloglucan is covalently linked to the pectic polysaccharides and is noncovalently bound to the cellulose fibrils of the sycamore cell wall. The molecular structure of sycamore xyloglucan was characterized by methylation analysis of the oligosaccharides obtained by endoglucanase treatment of the polymer. The structure of the polymer is based on a repeating heptasaccharide unit which consists of 4 residues of β-1-4-linked glucose and 3 residues of terminal xylose. A single xylose residue is glycosidically linked to carbon 6 of 3 of the glucosyl residues. PMID:16658281

  16. Experiments on rapidly-sheared wall turbulence

    NASA Astrophysics Data System (ADS)

    Diwan, Sourabh; Morrison, Jonathan

    2013-11-01

    The use of linear theories in wall turbulence dates back to Townsend (1976, Cambridge University Press) who extensively used Rapid Distortion Theory (RDT) for understanding the structure of near-wall turbulence. Various other linear tools have been used in more recent investigations. The present study is an attempt to further explore this aspect and is in part motivated by the recent numerical work of Sharma et al. (Phys. Fluids 23, 2011) that highlighted the possible role of linear mechanisms in wall turbulence. Our experimental arrangement involves passing a grid-generated turbulent flow over a flat plate mounted downstream of the grid in a wind tunnel. The grid turbulence is subjected to large rates of shear strain by the wall layer close to the leading edge of the plate and as a result, over a certain region in its vicinity, the approximations of the RDT can be expected to be approximately satisfied. We present detailed single-point and planar velocity measurements, and pressure measurements using surface-mounted pressure transducers, the aim being to establish a turbulent wall layer in which linear processes are dominant. Such a flow can be used to evaluate the ideas relating to linear theories of Townsend and Landahl, among others. We also present the structural changes that take place as the rapidly-sheared wall layer evolves towards a more conventional boundary layer further downstream. We acknowledge financial support from EPSRC under Grant No. EP/I037938.

  17. Tuberculous abscess on the chest wall.

    PubMed

    Aylk, S; Qakan, A; Aslankara, N; Ozsöz, A

    2009-03-01

    A 58-year old patient on dialysis for four years due to chronic renal failure presented with complaints of painless, continuously growing swelling on the left of his back and coughing, symptoms evolving over a period of approximately 3 months. Physical examination revealed a soft fixed mass of 10 x 10 x 4 cm on the left infrascapular area on the chest wall. The sample taken from the inflammation on the chest wall was analyzed with PCR method which resulted positive for Acid Fast Bacilli (AFB), tissue biopsy showed dermatitis with granulomata and sputum was positive for AFB. Thoracic MR, performed for the purpose of detecting the relationship between the lesion on the lung and the one on the chest wall, detected changes in the inflammatory soft tissues and multiple small abscess formations on the chest wall. There was no pathological signal in the bone structures of the chest wall. This case underlines the necessity to include "Empyema necessitatis" in the preliminary diagnosis when there is a soft tissue swelling on the chest wall without inflammatory signs in patients with reduced immune defences.

  18. A Wall of Funnels Concentrates Swimming Bacteria▿

    PubMed Central

    Galajda, Peter; Keymer, Juan; Chaikin, Paul; Austin, Robert

    2007-01-01

    Randomly moving but self-propelled agents, such as Escherichia coli bacteria, are expected to fill a volume homogeneously. However, we show that when a population of bacteria is exposed to a microfabricated wall of funnel-shaped openings, the random motion of bacteria through the openings is rectified by tracking (trapping) of the swimming bacteria along the funnel wall. This leads to a buildup of the concentration of swimming cells on the narrow opening side of the funnel wall but no concentration of nonswimming cells. Similarly, we show that a series of such funnel walls functions as a multistage pump and can increase the concentration of motile bacteria exponentially with the number of walls. The funnel wall can be arranged along arbitrary shapes and cause the bacteria to form well-defined patterns. The funnel effect may also have implications on the transport and distribution of motile microorganisms in irregular confined environments, such as porous media, wet soil, or biological tissue, or act as a selection pressure in evolution experiments. PMID:17890308

  19. Structure of Plant Cell Walls 1

    PubMed Central

    Ishii, Tadashi; Thomas, Jerry; Darvill, Alan; Albersheim, Peter

    1989-01-01

    Considerable information has been obtained about the primary structures of suspension-cultured sycamore (Acer pseudoplatanus) cell-wall pectic polysaccharides, i.e. rhamnogalacturonan I, rhamnogalacturonan II, and homogalacturonan. However, these polysaccharides, which are solubilized from the walls by endo-α-1,4-polygalacturonase, account for only about half of the pectic polysaccharides known to be present in sycamore cell walls. We now report that, after exhaustive treatment with endo-α-1,4-polygalacturonase, additional pectic polysaccharides were extracted from sycamore cell walls by treatment with Na2CO3 at 1 and 22°C. These previously uncharacterized polysaccharides accounted for ∼4% of the cell wall. Based on the glycosyl and glycosyl-linkage compositions and the nature of the products obtained by treating the quantitatively predominant NaCO3-extracted polysaccharides with lithium metal dissolved in ethylenediamine, the polysaccharides were found to strongly resemble rhamnogalacturonan I. However, unlike rhamnogalacturonan I that characteristically had equal amounts of 2- and 2,4-linked rhamnosyl residues in its backbone, the polysaccharides extracted in Na2CO3 at 1°C had markedly disparate ratios of 2- to 2,4-linked rhamnosyl residues. We concluded that polysaccharides similar to rhamnogalacturonan I but with different degrees of branching are present in the walls of suspension-cultured sycamore cells. PMID:16666559

  20. 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.

  1. Modelling of Ion Cyclotron Wall Conditioning plasmas

    NASA Astrophysics Data System (ADS)

    Douai, D.; Wauters, T.; Lyssoivan, A.; Marchuk, O.; Wünderlich, D.; Brémond, S.; Lombard, G.; Mollard, P.; Pegourié, B.; Van Oost, G.

    2011-12-01

    Ion Cyclotron Wall Conditioning (ICWC) is envisioned in ITER to clean the wall from impurities, to control the wall isotopic ratio and the hydrogen recycling in the presence of the toroidal magnetic field. Various experiments and modelling are advancing to consolidate this technique. In this contribution the modeling of ICWC is presented, which can be divided in two parts: plasma description and plasma wall interaction. Firstly a 0D plasma model, based on a set of energy and particle balance equations for Maxwellian Hydrogen and Helium species, is presented. The model takes into account elementary collision processes, coupled RF power, particle confinement, wall recycling, and active gas injection and pumping. The RF plasma production process is based mainly on electron collisional ionization. The dependency of the plasma parameters, the Hydrogen and Helium partial pressures and neutral or ionic fluxes on pressure and RF power are quantitatively in good agreement with those obtained experimentally on TORE SUPRA. Secondly an extension of the 0D model including the description of the wall interaction is presented and compared to TORE SUPRA multi-pulse ICWC discharges.

  2. 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.

  3. Sound Bridging By Wall Ties in Cavity Brick Walls: Theory and Experiment

    NASA Astrophysics Data System (ADS)

    Narang, P. P.

    1994-07-01

    In cavity brick wall construction, wall ties are frequently used to provide resistance to water penetration and to transfer lateral forces, thereby increasing the load-carrying capacity of the wall. The presence of such ties, however, introduces an additional path through which sound and vibration transmission can take place. As a consequence, the sound insulation performance of cavity walls with ties may be lower than those of identical walls with no ties. In this paper, sound transmission loss results obtained from laboratory measurements on a common cavity wall system with two different types of wall ties are reported. The statistical energy analysis (SEA) method is used to construct a model representing a cavity wall system with or without ties, and predicted airborne sound transmission loss values are compared with experimental results. By considering the wall ties as rigid point bridges that excite the second leaf, which in turn radiates the transmitted sound power, expressions are developed that allow the calculation of the reduction in transmission loss at different frequencies. Reasonable agreement between theory and experimental results has been found by using both methods.

  4. Double-walled carbon nanotube processing.

    PubMed

    Moore, Katherine E; Tune, Daniel D; Flavel, Benjamin S

    2015-05-27

    Single-walled carbon nanotubes (SWCNTs) have been the focus of intense research, and the body of literature continues to grow exponentially, despite more than two decades having passed since the first reports. As well as extensive studies of the fundamental properties, this has seen SWCNTs used in a plethora of applications as far ranging as microelectronics, energy storage, solar cells, and sensors, to cancer treatment, drug delivery, and neuronal interfaces. On the other hand, the properties and applications of double-walled carbon nanotubes (DWCNTs) have remained relatively under-explored. This is despite DWCNTs not only sharing many of the same unique characteristics of their single-walled counterparts, but also possessing an additional suite of potentially advantageous properties arising due to the presence of the second wall and the often complex inter-wall interactions that arise. For example, it is envisaged that the outer wall can be selectively functionalized whilst still leaving the inner wall in its pristine state and available for signal transduction. A similar situation arises in DWCNT field effect transistors (FETs), where the outer wall can provide a convenient degree of chemical shielding of the inner wall from the external environment, allowing the excellent transconductance properties of the pristine nanotubes to be more fully exploited. Additionally, DWCNTs should also offer unique opportunities to further the fundamental understanding of the inter-wall interactions within and between carbon nanotubes. However, the realization of these goals has so far been limited by the same challenge experienced by the SWCNT field until recent years, namely, the inherent heterogeneity of raw, as-produced DWCNT material. As such, there is now an emerging field of research regarding DWCNT processing that focuses on the preparation of material of defined length, diameter and electronic type, and which is rapidly building upon the experience gained by the broader

  5. 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.

  6. 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).

  7. 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.

  8. 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.

  9. Interactions between domain walls and spin currents

    NASA Astrophysics Data System (ADS)

    Klaui, M.; Laufenberg, M.; Backes, D.; Buhrer, W.; Rudiger, U.; Vila, L.; Vouille, C.; Faini, G.

    2006-03-01

    A promising novel approach for switching magnetic nanostructures is current-induced domain wall propagation (CIDP), where due to a spin torque effect, electrons transfer angular momentum to a head-to-head domain wall and thereby push it in the direction of the electron flow without any externally applied fields. This effect has been observed with a variety of techniques including MFM [1] and spin polarized scanning electron microscopy [2] to directly observe current-induced domain wall propagation in ferromagnetic nanostructures and magnetoresistance measurements to systematically probe the critical current densities as a function of the geometry [3]. The observed wall velocities and critical current densities, where wall motion sets in at room temperature, do not agree well with theoretical 0K calculations [4]. We have therefore measured the critical current densities as a function of the sample temperature. We find that the spin torque effect becomes more efficient at low temperatures, which could account for some of the observed discrepancies between the 300K experiment and the 0K simulation. [1] A. Yamaguchi et al., Phys. Rev. Lett. 92, 77205 (2004); [2] M. Klaui et al., PRL 95, 26601 (2005); [3] M. Klaui et al., PRL 94, 106601 (2005); [4] A. Thiaville et al., EPL 69, 990 (2005); G. Tatara et al., APL 86, 252509 (2005);

  10. New technologies for subsurface barrier wall construction

    SciTech Connect

    Mutch, R.D. Jr.; Ash, R.E. IV; Caputi, J.R.

    1996-12-31

    New technologies for subsurface barrier wall construction are entering the marketplace at an unprecedented pace. Much of this innovation centers around construction of geomembrane barrier walls but also includes advancements in self-hardening slurries and in permeation grouts, involving such diverse materials as colloidal silica gel and montan wax emulsions. These advancements come at a time when subsurface barrier walls are cautiously emerging out of the technological closet. During much of the 1980s, barrier walls of any type were regarded in some quarters as crude and antiquated. It was correspondingly predicted that remediation would be dominated by emerging treatment technologies such as bioremediation, air sparging, and surfactant flushing. Notwithstanding the considerable successes of these emerging technologies, particularly bioremediation, the fact remains that a significant percentage of Superfund, RCRA-corrective action and other waste disposal sites present hydrogeologic, chemical, and waste matrix complexities that far exceed the capabilities of current treatment-based remedial technologies. Consequently, containment-based technologies such as subsurface barrier walls and caps are being recognized once again as irreplaceable components of practical remediation programs at many complex sites.

  11. High accuracy wall thickness loss monitoring

    NASA Astrophysics Data System (ADS)

    Gajdacsi, Attila; Cegla, Frederic

    2014-02-01

    Ultrasonic inspection of wall thickness in pipes is a standard technique applied widely in the petrochemical industry. The potential precision of repeat measurements with permanently installed ultrasonic sensors however significantly surpasses that of handheld sensors as uncertainties associated with coupling fluids and positional offsets are eliminated. With permanently installed sensors the precise evaluation of very small wall loss rates becomes feasible in a matter of hours. The improved accuracy and speed of wall loss rate measurements can be used to evaluate and develop more effective mitigation strategies. This paper presents an overview of factors causing variability in the ultrasonic measurements which are then systematically addressed and an experimental setup with the best achievable stability based on these considerations is presented. In the experimental setup galvanic corrosion is used to induce predictable and very small wall thickness loss. Furthermore, it is shown that the experimental measurements can be used to assess the effect of reduced wall loss that is produced by the injection of corrosion inhibitor. The measurements show an estimated standard deviation of about 20nm, which in turn allows us to evaluate the effect and behaviour of corrosion inhibitors within less than an hour.

  12. 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

  13. 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.

  14. Thick-wall effects in the theory of resistive wall modes

    SciTech Connect

    Pustovitov, V. D.

    2012-06-15

    Magnetic interaction of the plasma perturbations with the nearby resistive wall is considered as a resistive wall mode (RWM) problem, but with two essential differences from the traditional thin-wall approach. First, the wall is treated as magnetically thick, which means that the skin depth is not assumed larger than the wall thickness. Second, the plasma is allowed to enter the region where the RWM must be deeply unstable without rotation. The latter corresponds to the plasma operation above the no-wall stability limit demonstrated in the DIII-D tokamak [E. J. Strait et al., Phys. Plasmas 11, 2505 (2004)]. It is shown that the rotational stabilization observed in these experiments can be reproduced in this model if the mode is forced to rotate with a frequency above a critical level. The analytical estimates show that this effect (absent in the model based on the thin-wall approximation) is strong at realistic parameters. The model also predicts that the locking of the rotationally stabilized mode gives rise to instability with a growth rate much larger than its thin-wall estimate.

  15. 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.

  16. 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

  17. 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. PMID:19798859

  18. Comparison of Turbulent Heat-Transfer Results for Uniform Wall Heat Flux and Uniform Wall Temperature

    NASA Technical Reports Server (NTRS)

    Siegel, R.; Sparrow, E. M.

    1960-01-01

    The purpose of this note is to examine in a more precise way how the Nusselt numbers for turbulent heat transfer in both the fully developed and thermal entrance regions of a circular tube are affected by two different wall boundary conditions. The comparisons are made for: (a) Uniform wall temperature (UWT); and (b) uniform wall heat flux (UHF). Several papers which have been concerned with the turbulent thermal entrance region problem are given. 1 Although these analyses have all utilized an eigenvalue formulation for the thermal entrance region there were differences in the choices of eddy diffusivity expressions, velocity distributions, and methods for carrying out the numerical solutions. These differences were also found in the fully developed analyses. Hence when making a comparison of the analytical results for uniform wall temperature and uniform wall heat flux, it was not known if differences in the Nusselt numbers could be wholly attributed to the difference in wall boundary conditions, since all the analytical results were not obtained in a consistent way. To have results which could be directly compared, computations were carried out for the uniform wall temperature case, using the same eddy diffusivity, velocity distribution, and digital computer program employed for uniform wall heat flux. In addition, the previous work was extended to a lower Reynolds number range so that comparisons could be made over a wide range of both Reynolds and Prandtl numbers.

  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. Wall ablation, gas dynamics, and the history of wall stresses in ICF target chambers

    SciTech Connect

    Orth, C.D. )

    1989-09-30

    We calculate the history of wall stresses for spherical aluminum LMF-type ICF target chambers 10 cm thick with 1400-MJ pellets using a simple computer program called CHAMBER that incorporates the physics of first-wall ablation and chamber gas dynamics, including dissociation, ionization, and gas reverberations. By considering the time dependence of the wall stresses, we calculate peak stresses that are higher or lower than previous estimates based on the dynamic formula {sigma}{sub dyn} {approx}Pr/{Delta}R, depending on the radius of the chamber. Here P is the interior pressure, R is the chamber radius, and {Delta}R is the wall thickness. In particular, the previous estimates are too small for chambers with radii R > 4 m or R < 0.5 m, because the ablation impulse dominates the stress for R > 4 m, and the post-ablation pressure impulse dominates for R < 0.5 cm. CHAMER also shows that considerably more wall mass can be ablated after the x-ray-vaporized mass fills the chamber if the thermalized vapor radiates more energy to the wall than the wall can conduct away by heat condition, as in small chambers. Venting of a chamber can reduce the wall stress only to that caused by the ablation impulse, and only for vents with radii comparable to the radius of the chamber. 1 ref., 2 figs.

  1. Plant cell wall dynamics and wall-related susceptibility in plant-pathogen interactions.

    PubMed

    Bellincampi, Daniela; Cervone, Felice; Lionetti, Vincenzo

    2014-01-01

    The cell wall is a dynamic structure that often determines the outcome of the interactions between plants and pathogens. It is a barrier that pathogens need to breach to colonize the plant tissue. While fungal necrotrophs extensively destroy the integrity of the cell wall through the combined action of degrading enzymes, biotrophic fungi require a more localized and controlled degradation of the cell wall in order to keep the host cells alive and utilize their feeding structures. Also bacteria and nematodes need to degrade the plant cell wall at a certain stage of their infection process, to obtain nutrients for their growth. Plants have developed a system for sensing pathogens and monitoring the cell wall integrity, upon which they activate defense responses that lead to a dynamic cell wall remodeling required to prevent the disease. Pathogens, on the other hand, may exploit the host cell wall metabolism to support the infection. We review here the strategies utilized by both plants and pathogens to prevail in the cell wall battleground.

  2. Plant cell wall dynamics and wall-related susceptibility in plant–pathogen interactions

    PubMed Central

    Bellincampi, Daniela; Cervone, Felice; Lionetti, Vincenzo

    2014-01-01

    The cell wall is a dynamic structure that often determines the outcome of the interactions between plants and pathogens. It is a barrier that pathogens need to breach to colonize the plant tissue. While fungal necrotrophs extensively destroy the integrity of the cell wall through the combined action of degrading enzymes, biotrophic fungi require a more localized and controlled degradation of the cell wall in order to keep the host cells alive and utilize their feeding structures. Also bacteria and nematodes need to degrade the plant cell wall at a certain stage of their infection process, to obtain nutrients for their growth. Plants have developed a system for sensing pathogens and monitoring the cell wall integrity, upon which they activate defense responses that lead to a dynamic cell wall remodeling required to prevent the disease. Pathogens, on the other hand, may exploit the host cell wall metabolism to support the infection. We review here the strategies utilized by both plants and pathogens to prevail in the cell wall battleground. PMID:24904623

  3. 1. AIR/MANWAY SHAFT WALL AND FAN HOUSE FOUNDATION WALL FROM ...

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

    1. AIR/MANWAY SHAFT WALL AND FAN HOUSE FOUNDATION WALL FROM NORTHWEST. AEROVANE FAN AT UPPER LEFT, SCAFFOLD AND LEPLEY VENTILATOR AT UPPER RIGHT. - Consolidation Coal Company Mine No. 11, Air-Manway Shaft, East side of State Route 936, Midlothian, Allegany County, MD

  4. 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.

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

    PubMed Central

    2011-01-01

    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. PMID:27502675

  6. Wall thickness measuring method and apparatus

    DOEpatents

    Salzer, L.J.; Bergren, D.A.

    1987-10-06

    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.

  7. 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.

  8. 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.

  9. 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.

  10. Turbine airfoil with a compliant outer wall

    DOEpatents

    Campbell, Christian X.; Morrison, Jay A.

    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.

  11. 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.

  12. Domain wall conduction in multiaxial ferroelectrics

    SciTech Connect

    Eliseev, E. A.; Morozovska, A. N.; Svechnikov, S. V.; Maksymovych, Petro; Kalinin, Sergei V

    2012-01-01

    The conductance of domain wall structures consisting of either stripes or cylindrical domains in multiaxial ferroelectric-semiconductors is analyzed. The effects of the flexoelectric coupling, domain size, wall tilt, and curvature on charge accumulation are analyzed using the Landau-Ginsburg Devonshire theory for polarization vector combined with the Poisson equation for charge distributions. The proximity and size effect of the electron and donor accumulation/depletion by thin stripe domains and cylindrical nanodomains are revealed. In contrast to thick domain stripes and wider cylindrical domains, in which the carrier accumulation (and so the static conductivity) sharply increases at the domain walls only, small nanodomains of radii less than 5-10 correlation lengths appeared conducting across the entire cross-section. Implications of such conductive nanosized channels may be promising for nanoelectronics.

  13. Untethered photonic sensor for wall pressure measurement.

    PubMed

    Manzo, Maurizio; Ioppolo, Tindaro

    2015-05-15

    In this Letter, we study a novel untethered photonic wall pressure sensor that uses as sensing element a dome-shaped micro-scale laser. Since the sensor does not require any optical or electrical cabling, it allows measurements where cabling tends to be problematic. The micro-laser is made by a mixture of Trimethylolpropane Tri(3-mercaptopropionate), commercial name THIOCURE and Polyethylene (glycol) Diacrylate (PEGDA) mixed with a solution of rhodamine 6G. Two different volume ratios between the THIOCURE and the PEGDA are studied, since different ratios lead to different mechanical properties. In addition, two different sensor configurations are presented: (i) sensor coupled to a membrane, that allows differential wall pressure measurement and (ii) sensor without membrane that allows absolute wall pressure measurement. The sensitivity plots are presented in the paper for both sensor configurations and polymer ratios.

  14. 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.

  15. Planctomycetes do possess a peptidoglycan cell wall

    PubMed Central

    Jeske, Olga; Schüler, Margarete; Schumann, Peter; Schneider, Alexander; Boedeker, Christian; Jogler, Mareike; Bollschweiler, Daniel; Rohde, Manfred; Mayer, Christoph; Engelhardt, Harald; Spring, Stefan; Jogler, Christian

    2015-01-01

    Most bacteria contain a peptidoglycan (PG) cell wall, which is critical for maintenance of shape and important for cell division. In contrast, Planctomycetes have been proposed to produce a proteinaceous cell wall devoid of PG. The apparent absence of PG has been used as an argument for the putative planctomycetal ancestry of all bacterial lineages. Here we show, employing multiple bioinformatic methods, that planctomycetal genomes encode proteins required for PG synthesis. Furthermore, we biochemically demonstrate the presence of the sugar and the peptide components of PG in Planctomycetes. In addition, light and electron microscopic experiments reveal planctomycetal PG sacculi that are susceptible to lysozyme treatment. Finally, cryo-electron tomography demonstrates that Planctomycetes possess a typical PG cell wall and that their cellular architecture is thus more similar to that of other Gram-negative bacteria. Our findings shed new light on the cellular architecture and cell division of the maverick Planctomycetes. PMID:25964217

  16. 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.

  17. 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...

  18. 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.

  19. 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.

  20. Acellular dermal matrix in abdominal wall reconstruction.

    PubMed

    Silverman, Ronald P

    2011-09-01

    Abdominal wall reconstruction is a complex and challenging surgical undertaking. While permanent prosthetic mesh is considered the gold standard for minimizing hernia recurrence, placement of synthetic mesh is sometimes imprudent due to contamination or risk of infection. Acellular dermal matrices (ADM) offer an exciting biologic alternative. This article provides a historical perspective on the evolution of complex ventral hernia repair leading up to and including the placement of ADM, an explanation of the biology of ADM as it relates to ventral hernia repair, and a description of the current indications, techniques, benefits, and shortcomings of its use in the abdominal wall.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Early changes in wall motion and wall thickness during percutaneous transluminal coronary angioplasty in man.

    PubMed

    Serruys, P W; Jaski, B; Wijns, W; Piscione, F; ten Kate, F; de Feyter, P; van den Brand, M; Hugenholtz, P G

    1986-07-01

    Epicardial wall motion, myocardial wall thickness and segmental wall motion during percutaneous transluminal coronary angioplasty, a situation which resembles the experimental abrupt occlusion of a major coronary artery in the animal laboratory, have been studied in patients undergoing the procedure. Epicardial wall motion was analyzed using biplane cineradiography with frame to frame measurements of distances between pairs of radiopaque epicardial markers, placed at the time of previous cardiac surgery in a patient with a stenosis of a coronary artery bypass graft. Bypass graft occlusion led to early onset of biphasic epicardial late systolic lengthening and early diastolic shortening similar to the regional wall motion abnormality preceding the procedure. Continuous M-mode echocardiogram throughout coronary luminal occlusion, showed a decreased systolic thickening in the septum with a concomitant, prominent notch in early diastole occurring after the seventh beat following occlusion. At the 28th beat, septal systolic motion was absent while only an early diastolic septal motion was observed. Contemporaneously the end-diastolic septal thickness results decreased. Segmental wall motion analysis during ischemia was carried out performing a left ventricular angiogram before, 20 and 50 seconds after the onset of balloon inflation, 5 minutes after completion of the procedure. During the early phase of ischemia, in the ischemic segments, a late systolic lengthening with an early diastolic shortening was observed. We refer to this biphasic motion as the "W" phenomenon which appears to be the early and characteristic change in wall motion and thickness during coronary angioplasty in man.

  6. 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.

  7. Tailoring wall permeabilities for enhanced filtration

    NASA Astrophysics Data System (ADS)

    Herterich, J. G.; Vella, D.; Field, R. W.; Hankins, N. P.; Griffiths, I. M.

    2015-05-01

    The build-up of contaminants at the wall of cross-flow membrane filtration systems can be detrimental to the operation of such systems because of, amongst other things, the osmotic backflow it may induce. In this paper, we propose a strategy to avoid the negative effects of backflow due to osmosis by using 2D channels bounded by walls with a combination of permeable and impermeable segments. We show that preventing flow through the final portion of the channel can increase the efficiency of filtration and we determine the optimal fraction occupied by the permeable wall that maximizes efficiency. Our analysis uses a combination of numerical techniques and asymptotic analysis in the limit of low wall permeabilities. Finally, we consider how the energy cost of filtration depends on the Péclet number and show that the energy cost per unit of filtered water may be minimized by appropriately choosing both the Péclet number and the permeable-region fraction.

  8. New scaling for compressible wall turbulence

    NASA Astrophysics Data System (ADS)

    Pei, Jie; Chen, Jun; Fazle, Hussain; She, ZhenSu

    2013-09-01

    Classical Mach-number (M) scaling in compressible wall turbulence was suggested by van Driest (Van Driest E R. Turbulent boundary layers in compressible fluids. J Aerodynamics Science, 1951, 18(3): 145-160) and Huang et al. (Huang P G, Coleman G N, Bradshaw P. Compressible turbulent channel flows: DNS results and modeling. J Fluid Mech, 1995, 305: 185-218). Using a concept of velocity-vorticity correlation structure (VVCS), defined by high correlation regions in a field of two-point cross-correlation coefficient between a velocity and a vorticity component, we have discovered a limiting VVCS as the closest streamwise vortex structure to the wall, which provides a concrete Morkovin scaling summarizing all compressibility effects. Specifically, when the height and mean velocity of the limiting VVCS are used as the units for the length scale and the velocity, all geometrical measures in the spanwise and normal directions, as well as the mean velocity and fluctuation (r.m.s) profiles become M-independent. The results are validated by direct numerical simulations (DNS) of compressible channel flows with M up to 3. Furthermore, a quantitative model is found for the M-scaling in terms of the wall density, which is also validated by the DNS data. These findings yield a geometrical interpretation of the semi-local transformation (Huang et al., 1995), and a conclusion that the location and the thermodynamic properties associated with the limiting VVCS determine the M-effects on supersonic wall-bounded flows.

  9. Solitary fibrous tumour of the chest wall.

    PubMed

    Mohtarrudin, N; Nor Hanipah, Z; Mohd Dusa, N

    2016-04-01

    Extrapleural solitary fibrous tumours (SFTs) are rare tumours characterized by patternless spindle cells with haemangiopericytoma-like vascular spaces. Previously the tumours have been classified as haemangiopericytoma, an entity that is now considered obsolete. We report a case of extrapleural SFT arising in the soft tissue of the chest wall. The patient was a 31-year-old Malay lady presenting with a mobile swelling of the right chest wall for more than five years. During excision the tumour was noted to be well-circumscribed and yellowish in colour, giving an impression of lipoma. Microscopically, the tumour had patternless architecture, characterized by hypocellular and hypercellular areas. It was composed of uniform, spindle-shaped cells displaying oval nuclei, inconspicuous nucleoli, pale cytoplasm and indistinct cell borders. The mitotic count was 2 per 10 HPF. Branching, medium-sized thin-walled blood vessels in a haemangiopericytomatous growth pattern, some with hyalinised wall were identified. The neoplastic cells were immunoreactive to CD99 and CD34 and were non-immunoreactive to Desmin, Smooth Muscle Actin, S100 protein and EMA. We elucidate the challenges in diagnosing this tumour in this unusual location.

  10. Solitary fibrous tumour of the chest wall.

    PubMed

    Mohtarrudin, N; Nor Hanipah, Z; Mohd Dusa, N

    2016-04-01

    Extrapleural solitary fibrous tumours (SFTs) are rare tumours characterized by patternless spindle cells with haemangiopericytoma-like vascular spaces. Previously the tumours have been classified as haemangiopericytoma, an entity that is now considered obsolete. We report a case of extrapleural SFT arising in the soft tissue of the chest wall. The patient was a 31-year-old Malay lady presenting with a mobile swelling of the right chest wall for more than five years. During excision the tumour was noted to be well-circumscribed and yellowish in colour, giving an impression of lipoma. Microscopically, the tumour had patternless architecture, characterized by hypocellular and hypercellular areas. It was composed of uniform, spindle-shaped cells displaying oval nuclei, inconspicuous nucleoli, pale cytoplasm and indistinct cell borders. The mitotic count was 2 per 10 HPF. Branching, medium-sized thin-walled blood vessels in a haemangiopericytomatous growth pattern, some with hyalinised wall were identified. The neoplastic cells were immunoreactive to CD99 and CD34 and were non-immunoreactive to Desmin, Smooth Muscle Actin, S100 protein and EMA. We elucidate the challenges in diagnosing this tumour in this unusual location. PMID:27126667

  11. 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)

  12. 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.

  13. 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.

  14. Wall pressure fluctuations in rectangular partial enclosures

    NASA Astrophysics Data System (ADS)

    Pagliaroli, T.; Camussi, R.

    2015-04-01

    Wall pressure fluctuations generated within rectangular partial enclosures (RPEs) have been studied experimentally for a broad range of geometrical parameters. The geometry represents a simplified version of a new generation trapped vortex combustor and consisted of a rectangular cavity connected to a neck of smaller size. Wall pressure fluctuations have been measured through wall mounted microphones providing single and multi-variate pressure statistics both in the physical space and in the Fourier domain. In order to interpret the pressure signals, aerodynamic and acoustic investigations have been carried out as well for several cavity-neck ratios. The analysis of the acoustic response of the cavity has been conducted both numerically and experimentally and a simple theoretical model has been proposed to predict the frequency of the acoustic resonances. The aerodynamic study has been carried out through PIV measurements that provided characterization in terms of the geometrical parameters of both the large-scale vortex generated within the cavity and the recirculation zone formed upstream of the neck. The use of the POD decomposition permitted us to correlate the dynamics of the recirculation with the observed pressure statistics. The aerodynamic and acoustic investigations allowed us to interpret exhaustively the wall pressure cross-statistics and to separate contributions induced by hydrodynamic and purely acoustic pressure fluctuations.

  15. 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.

  16. 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.

  17. 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.

  18. Where the Wall Will Fall First

    PubMed Central

    CARROLL, JOHN

    2007-01-01

    Most believe that ‘generic’ biologics are not a question of if, but when. Just when, though, and which therapies could face a threat in the marketplace, depend on the complexity of the product. Research is far along, indicating that some of today’s biggest markets could be exposed when the wall comes tumbling down. PMID:23319931

  19. 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

  20. 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…

  1. 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…

  2. 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)

  3. Myxoid Liposarcoma in the Abdominal Wall

    PubMed Central

    Fan, Zhe; Tian, Xiao Feng; Tang, Shun Xiong; Zhang, Ying Yi; Pan, Ji Yong; Wang, Shuang

    2014-01-01

    Abstract A liposarcoma is the most common type of soft tissue sarcoma, and most liposarcomas are malignant. The extremities are the most common site for liposarcomas. There are 5 histologic types of liposarcoma, as follows: well differentiated; myxoid; round cell; pleomorphic; and dedifferentiated. Myxoid liposarcomas (MLSs) represent a subgroup of liposarcomas. There has been no report of MLSs in the abdominal wall. We report a rare case of a MLS of a 43-year-old male who presented with tensile force on the abdominal wall. Computed tomography (CT) found a tumor in abdominal wall. There was no other abnormal symptom and the laboratory testing was also unusual. At last, the tumor was successfully excised, which was diagnosed MLSs in pathology. Following standard principles, after complete excision, the patient received radiotherapy. The patient was followed up for 8 month and no disease recurrence was identified. MLSs are rarely seen in the clinic, irrespective of the presenting signs, but also based on histologic features. The aim of this report was to present the differential diagnosis of an abdominal wall mass, and to remind us of MLSs. PMID:25526446

  4. 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.

  5. Saccharomyces cerevisiae structural cell wall mannoprotein.

    PubMed

    Frevert, J; Ballou, C E

    1985-01-29

    A novel mannoprotein fraction with an average molecular weight of 180 000 has been isolated from Saccharomyces cerevisiae mnn9 mutant cell wall that was solubilized by beta-glucanase digestion. The same material could be extracted from purified wall fragments with 1% sodium dodecyl sulfate. The protein component, 12% by weight, is rich in proline, whereas the carbohydrate, mainly mannose, is about evenly distributed between asparagine and hydroxyamino acids. Endoglucosaminidase H digestion of the isolated mannoprotein reduced its average molecular weight to 150 000, but the mannoprotein, while still embedded in the cell wall, was inaccessible to the enzyme. Biosynthesis and translocation of the mannoprotein were investigated by following incorporation of [3H]proline into this fraction. In the presence of tunicamycin, both mnn9 and wild-type X2180 cells made a mannoprotein fraction with an average molecular weight of 140 000, whereas in the absence of the glycosylation inhibitor, the mnn9 mutant made material with a molecular weight of 180 000 and the mannoprotein made by wild-type cells was too large to penetrate the polyacrylamide gel. Although the cell wall mannoprotein was resistant to heat and proteolytic enzymes, attempts to isolate the carbohydrate-free component failed to yield any characteristic peptide material. PMID:3888262

  6. 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).

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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

  13. Algorithm of chest wall keloid treatment.

    PubMed

    Long, Xiao; Zhang, Mingzi; Wang, Yang; Zhao, Ru; Wang, Youbin; Wang, Xiaojun

    2016-08-01

    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

  14. 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.

  15. 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. PMID:26661933

  16. 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.

  17. Chest wall reconstruction after resection using hernia repair piece.

    PubMed

    Wu, Yimin; Zhang, Guofei; Zhu, Zhouyu; Chai, Ying

    2016-06-01

    Reconstruction of chest wall tumor is very important link of chest wall tumor resection. Many implants have been reported to be used to reconstruct the chest wall, such as steelwire, titanium mesh and polypropylene mesh. It is really hard for clinicians to decide which implant is the best one to replace the chest wall. We herein report a 68-year-old man who had underwent a chest wall reconstruction with a hernia repair piece and a Dacron hernia repair piece. The patient has maintained an excellent cosmetic and functional outcome since surgery, which proves that the hernia piece still has its place in reconstruction of chest wall. PMID:27293859

  18. 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. PMID:27588878

  19. Examination and Disruption of the Yeast Cell Wall.

    PubMed

    Okada, Hiroki; Kono, Keiko; Neiman, Aaron M; Ohya, Yoshikazu

    2016-01-01

    The cell wall of Saccharomyces cerevisiae is a complicated extracellular organelle. Although the barrier may seem like a technical nuisance for researchers studying intracellular biomolecules or conditions, the rigid wall is an essential aspect of the yeast cell. Without it, yeast cells are unable to proliferate or carry out their life cycle. The chemical composition of the cell wall and the biosynthetic pathways and signal transduction mechanisms involved in cell wall remodeling have been studied extensively, but many unanswered questions remain. This introduction describes techniques for investigating abnormalities in the cell and spore walls and performing cell wall disruption. PMID:27480724

  20. 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.

  1. Antiferromagnetic Domain Wall Motion Driven by Spin-Orbit Torques

    NASA Astrophysics Data System (ADS)

    Shiino, Takayuki; Oh, Se-Hyeok; Haney, Paul M.; Lee, Seo-Won; Go, Gyungchoon; Park, Byong-Guk; Lee, Kyung-Jin

    2016-08-01

    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.

  2. Chest wall reconstruction after resection using hernia repair piece

    PubMed Central

    Wu, Yimin; Zhang, Guofei; Zhu, Zhouyu

    2016-01-01

    Reconstruction of chest wall tumor is very important link of chest wall tumor resection. Many implants have been reported to be used to reconstruct the chest wall, such as steelwire, titanium mesh and polypropylene mesh. It is really hard for clinicians to decide which implant is the best one to replace the chest wall. We herein report a 68-year-old man who had underwent a chest wall reconstruction with a hernia repair piece and a Dacron hernia repair piece. The patient has maintained an excellent cosmetic and functional outcome since surgery, which proves that the hernia piece still has its place in reconstruction of chest wall. PMID:27293859

  3. On determining wall shear stress in spatially developing two-dimensional wall-bounded flows

    NASA Astrophysics Data System (ADS)

    Mehdi, Faraz; Johansson, T. Gunnar; White, Christopher M.; Naughton, Jonathan W.

    2014-01-01

    A full momentum integral-based method for determining wall shear stress is presented. The method is mathematically exact and has the advantage of having no explicit streamwise gradient terms. It is applicable for flows that change rapidly in the streamwise direction and, in particular, to flows with ill-defined outer boundary conditions or when the measurement grid does not extend over the whole boundary layer thickness. The method is applied to two different experimental plane turbulent wall jet data sets for which independent estimates of wall shear stress were known, and the different results compare favorably. Complications owing to experimental limitations and measurement error in determining wall shear stress from the proposed method are presented, and mitigating strategies are described.

  4. [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. PMID:27365062

  5. Motion of a viscous fluid and a wall in the presence of a stationary wall

    NASA Astrophysics Data System (ADS)

    Sennitskii, V. L.

    2016-03-01

    The problem of damping motion of a hydromechanical system consisting of a viscous fluid and its bounding rigid walls is solved. A condition under which there is an abrupt deceleration of the hydromechanical system is determined.

  6. Reconstitution of a Secondary Cell Wall in a Secondary Cell Wall-Deficient Arabidopsis Mutant

    PubMed Central

    Sakamoto, Shingo; Mitsuda, Nobutaka

    2015-01-01

    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. PMID:25535195

  7. 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.

  8. 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.

  9. 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

  10. Engineering the Oryza sativa cell wall with rice NAC transcription factors regulating secondary wall formation.

    PubMed

    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

  11. Increased wall-to-wall curing contraction in thin bonded resin layers.

    PubMed

    Feilzer, A J; De Gee, A J; Davidson, C L

    1989-01-01

    Wall-to-wall (WTW) polymerization contraction of filled and unfilled chemically and photo-initiated resins was studied in relation to the WTW distance. In an experimental set-up, the resins were bonded to two opposing disks, and the axial (WTW) displacement resulting from the polymerization shrinkage was measured continuously. It was found that the WTW contraction increased with decreasing WTW distance and ultimately reached a value of almost three times the linear polymerization shrinkage.

  12. Scale resolving computation of submerged wall jets on flat wall with different roughness heights

    NASA Astrophysics Data System (ADS)

    Paik, Joongcheol; Bombardelli, Fabian

    2014-11-01

    Scale-adaptive simulation is used to investigate the response of velocity and turbulence in submerged wall jets to abrupt changes from smooth to rough beds. The submerged wall jets were experimentally investigated by Dey and Sarkar [JFM, 556, 337, 2006] at the Reynolds number of 17500 the Froude number of 4.09 and the submergence ratio of 1.12 on different rough beds that were generated by uniform sediments of different median diameters The SAS is carried out by means of a second-order-accurate finite volume method in space and time and the effect of bottom roughness is treated by the approach of Cebeci (2004). The evolution of free surface is captured by employing the two-phase volume of fluid (VOF) technique. The numerical results obtained by the SAS approach, incorporated with the VOF and the rough wall treatment, are in good agreement with the experimental measurements. The computed turbulent boundary layer grows more quickly and the depression of the free surface is more increased on the rough wall than those on smooth wall. The size of the fully developed zone shrinks and the decay rate of maximum streamwise velocity and Reynolds stress components are faster with increase in the wall roughness. Supported by NSF and NRF of Korea.

  13. Controlled Patterning and Growth of Single Wall and Multi-wall Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Delzeit, Lance D. (Inventor)

    2005-01-01

    Method and system for producing a selected pattern or array of at least one of a single wall nanotube and/or a multi-wall nanotube containing primarily carbon. A substrate is coated with a first layer (optional) of a first selected metal (e.g., Al and/or Ir) and with a second layer of a catalyst (e.g., Fe, Co, Ni and/or Mo), having selected first and second layer thicknesses provided by ion sputtering, arc discharge, laser ablation, evaporation or CVD. The first layer and/or the second layer may be formed in a desired non-uniform pattern, using a mask with suitable aperture(s), to promote growth of carbon nanotubes in a corresponding pattern. A selected heated feed gas (primarily CH4 or C2Hn with n=2 and/or 4) is passed over the coated substrate and forms primarily single wall nanotubes or multiple wall nanotubes, depending upon the selected feed gas and its temperature. Nanofibers, as well as single wall and multi-wall nanotubes, are produced using plasma-aided growth from the second (catalyst) layer. An overcoating of a selected metal or alloy can be deposited, over the second layer, to provide a coating for the carbon nanotubes grown in this manner.

  14. Skyrmion domain wall collision and domain wall-gated skyrmion logic

    NASA Astrophysics Data System (ADS)

    Xing, Xiangjun; Pong, Philip W. T.; Zhou, Yan

    2016-08-01

    Skyrmions and domain walls are significant spin textures of great technological relevance to magnetic memory and logic applications, where they can be used as carriers of information. The unique topology of skyrmions makes them display emergent dynamical properties as compared with domain walls. Some studies have demonstrated that the two topologically inequivalent magnetic objects could be interconverted by using cleverly designed geometric structures. Here, we numerically address the skyrmion domain wall collision in a magnetic racetrack by introducing relative motion between the two objects based on a specially designed junction. An electric current serves as the driving force that moves a skyrmion toward a trapped domain wall pair. We see different types of collision dynamics depending on the driving parameters. Most importantly, the modulation of skyrmion transport using domain walls is realized in this system, allowing a set of domain wall-gated logical NOT, NAND, and NOR gates to be constructed. This work provides a skyrmion-based spin-logic architecture that is fully compatible with racetrack memories.

  15. Celery (Apium graveolens) parenchyma cell walls: cell walls with minimal xyloglucan.

    PubMed

    Thimm, Julian C.; Burritt, David J.; Sims, Ian M.; Newman, Roger H.; Ducker, William A.; Melton, Laurence D.

    2002-10-01

    The primary walls of celery (Apium graveolens L.) parenchyma cells were isolated and their polysaccharide components characterized by glycosyl linkage analysis, cross-polarization magic-angle spinning solid-state 13C nuclear magnetic resonance (CP/MAS 13C NMR) and X-ray diffraction. Glycosyl linkage analysis showed that the cell walls consisted of mainly cellulose (43 mol%) and pectic polysaccharides (51 mol%), comprising rhamnogalacturonan (28 mol%), arabinan (12 mol%) and galactan (11 mol%). The amounts of xyloglucan (2 mol%) and xylan (2 mol%) detected in the cell walls were strikingly low. The small amount of xyloglucan present means that it cannot coat the cellulose microfibrils. Solid-state 13C NMR signals were consistent with the constituents identified by glycosyl linkage analysis and allowed the walls to be divided into three domains, based on the rigidity of the polymers. Cellulose (rigid) and rhamnogalacturonan (semi-mobile) polymers responded to the CP/MAS 13C NMR pulse sequence and were distinguished by differences in proton spin relaxation time constants. The arabinans, the most mobile polymers, responded to single-pulse excitation (SPE), but not CP/MAS 13C NMR. From solid-state 13C NMR of the cell walls the diameter of the crystalline cellulose microfibrils was determined to be approximately 3 nm while X-ray diffraction of the cell walls gave a value for the diameter of approximately 2 nm.

  16. The Structure of Plant Cell Walls

    PubMed Central

    Talmadge, Kenneth W.; Keegstra, Kenneth; Bauer, Wolfgang D.; Albersheim, Peter

    1973-01-01

    This is the first in a series of papers dealing with the structure of cell walls isolated from suspension-cultured sycamore cells (Acer pseudoplatanus). These studies have been made possible by the availability of purified hydrolytic enzymes and by recent improvements in the techniques of methylation analysis. These techniques have permitted us to identify and quantitate the macromolecular components of sycamore cell walls. These walls are composed of 10% arabinan, 2% 3,6-linked arabinogalactan, 23% cellulose, 9% oligo-arabinosides (attached to hydroxyproline), 8% 4-linked galactan, 10% hydroxyproline-rich protein, 16% rhamnogalacturonan, and 21% xyloglucan. The structures of the pectic polymers (the neutral arabinan, the neutral galactan, and the acidic rhamnogalacturonan) were obtained, in part, by methylation analysis of fragments of these polymers which were released from the sycamore walls by the action of a highly purified endopolygalacturonase. The data suggest a branched arabinan and a linear 4-linked galactan occurring as side chains on the rhamnogalacturonan. Small amounts or pieces of a xyloglucan, the wall hemicellulose, appear to be covalently linked to some of the galactan chains. Thus, the galactan appears to serve as a bridge between the xyloglucan and rhamnogalacturonan components of the wall. The rhamnogalacturonan consists of an α-(1 → 4)-linked galacturonan chain which is interspersed with 2-linked rhamnosyl residues. The rhamnosyl residues are not randomly distributed in the chain but probably occur in units of rhamnosyl- (1 → 4)-galacturonosyl- (1 → 2)-rhamnosyl. This sequence appears to alternate with a homogalacturonan sequence containing approximately 8 residues of 4-linked galacturonic acid. About half of the rhamnosyl residues are branched, having a substituent attached to carbon 4. This is likely to be the site of attachment of the 4-linked galactan. The hydroxyprolyl oligo-arabinosides of the hydroxyproline-rich glycoprotein

  17. A possible formation mechanism of double-walled and multi-walled carbon nanotube: a molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Han, Dianrong; Luo, Chenglin; Dai, Yafei; Zhu, Xingfeng

    2016-09-01

    Molecular dynamics simulations based on an empirical potential were performed to study the interaction of graphene nanoribbons and the single-walled carbon nanotubes. The results indicated that a piece of graphene nanoribbon can form a tube structure inside or outside single-walled carbon nanotubes spontaneously under certain condition. Based on this kind of spontaneous phenomenon, we proposed a new possible formation mechanism of double walled carbon nanotube and multi-walled carbon nanotube, and suggested the possibility of controlling the structure of double-walled carbon nanotube and/or multi-walled carbon nanotube.

  18. Moisture in a straw bale wall

    SciTech Connect

    Brown, G.Z.; Fremouw, S.; Kline, J.; Northcutt, D.; Wang, Z.; Weiser, R.

    1999-07-01

    The objective of this project was to see if there was sufficient moisture to promote fungus growth within a straw bale wall. To determine the level of moisture, the walls in a straw bale building were instrumented to monitor relative humidity. The year-long monitoring began in August, 1997. During the monitoring period the building's interior relative humidity ranged from 22 to 71% and the exterior relative humidity ranged from 10 to 94%. The maximum straw bale relative humidity recorded was 85%, which occurred on February 21 on the south side of the building in a lower bale on the exterior side. The minimum straw bale relative humidity occurred on August 13 on the east side of the building in a lower bale on the exterior side and was 27%. In the 23 studies of mold growth in straw bales the authors reviewed, mold growth occurred between 70 and 91% relative humidity.

  19. Hydroide Storage Vessel wall stress measurements

    SciTech Connect

    Clark, E.A.; Pechersky, M.J.

    1997-07-31

    Holographic Interferometry and strain gauge measurements were used to determine whether a prototype Hydride Storage Vessel (HSV) swelled while it was loaded in eleven stages with hydrogen. Bed swelling is inferred from deformation of the surface of the HSV. No swelling was detected, even after saturating the hydride material inside the HSV. The large chunky morphology of the titanium is likely responsible for the lack of wall stress. This morphology also implies that decay helium that remains in the titanium hydride (that is, helium that is not released as gas to the free volume) should not cause significant wall stresses when the HSV is used for long-term tritium storage. Holographic interferometry proved to be an extremely sensitive technique to measure swelling, having a detection limit of about 3 microns surface displacement.

  20. The Kevlar-walled anechoic wind tunnel

    NASA Astrophysics Data System (ADS)

    Devenport, William J.; Burdisso, Ricardo A.; Borgoltz, Aurelien; Ravetta, Patricio A.; Barone, Matthew F.; Brown, Kenneth A.; Morton, Michael A.

    2013-08-01

    The aerodynamic and acoustic performance of an anechoic wind tunnel test section with walls made from thin Kevlar cloth have been measured and analyzed. The Kevlar test section offers some advantages over a conventional free-jet arrangement. The cloth contains the bulk of the flow but permits the transmission of sound with little loss. The containment results in smaller far-field aerodynamic corrections meaning that larger models can be tested at higher Reynolds numbers. The containment also eliminates the need for a jet catcher and allows for a much longer test section. Model-generated noise is thus more easily separated from facility background using beamforming. Measurements and analysis of acoustic and aerodynamic corrections for a Kevlar-walled test section are presented and discussed, along with benchmark trailing edge noise measurements.

  1. Solitary fibrous tumor of the abdominal wall.

    PubMed

    Migita, Kazuhiro; Watanabe, Akihiko; Nakagawa, Kenji; Ohyama, Takao; Sekigawa, Susumu

    2009-12-01

    Solitary fibrous tumors (SFTs) are uncommon neoplasms of mesenchymal origin that usually arise from the pleura. SFTs of the abdominal wall are extremely rare, and only 12 cases have been reported in the English language literature. This report presents a new case of SFT of the abdominal wall in a 74-year-old female. Positron emission tomography demonstrated the heterogeneous 18F-fluorodeoxyglucose uptake of the tumor (the maximum standardized uptake value was 2.8). Histologically, the mitotic count was 1 to 2/10 high-power fields. The patient is alive without recurrence at 10 months after undergoing a surgical excision. We discuss the clinicopathological features and differential diagnosis and present a review of the pertinent literature.

  2. From Boltzmann equations to steady wall velocities

    SciTech Connect

    Konstandin, Thomas; Nardini, Germano; Rues, Ingo E-mail: germano.nardini@desy.de

    2014-09-01

    By means of a relativistic microscopic approach we calculate the expansion velocity of bubbles generated during a first-order electroweak phase transition. In particular, we use the gradient expansion of the Kadanoff-Baym equations to set up the fluid system. This turns out to be equivalent to the one found in the semi-classical approach in the non-relativistic limit. Finally, by including hydrodynamic deflagration effects and solving the Higgs equations of motion in the fluid, we determine velocity and thickness of the bubble walls. Our findings are compared with phenomenological models of wall velocities. As illustrative examples, we apply these results to three theories providing first-order phase transitions with a particle content in the thermal plasma that resembles the Standard Model.

  3. Adding crumb rubber into exterior wall materials.

    PubMed

    Zhu, Han; Thong-On, Norasit; Zhang, Xiong

    2002-10-01

    In Arizona US, most houses are built with walls covered by stuccos/coatings/mortars. This paper presents an explorative investigation of adding crumb rubber into stuccos/coatings/mortars. A series of experiments are conducted to examine the thermal and mechanical performance of the crumb rubber mixes. The results show that, the mixes with crumb rubber do exhibit more desirable performances like being high in crack-resistance and thermal insulation, and low in thermal expansion/contraction. The drawback for the crumb rubber mixes is the reduction in compressive strength, but which can be compensated by other means. As a site experiment, an area of 100 square-feet of crumb rubber coatings for two mix designs is sprayed on a tire-adobe wall. After being sprayed more than 14 months, the coatings apparently are in good condition. Significance of this study is that this practice, if accepted, will yield improved products that consume large quantities of crumb rubber.

  4. Enhanced dielectric-wall linear accelerator

    DOEpatents

    Sampayan, Stephen E.; Caporaso, George J.; Kirbie, Hugh C.

    1998-01-01

    A dielectric-wall linear accelerator is enhanced by a high-voltage, fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.

  5. Enhanced dielectric-wall linear accelerator

    DOEpatents

    Sampayan, S.E.; Caporaso, G.J.; Kirbie, H.C.

    1998-09-22

    A dielectric-wall linear accelerator is enhanced by a high-voltage, fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 6 figs.

  6. How to measure inner urethral wall softness.

    PubMed

    Plevnik, S; Vrtacnik, P

    1981-01-01

    The objective of this study was to develop and preliminarily test the measuring principle suitable for quantification of the capability of deformation of the inner urethral wall, i.e. quantification of inner urethral wall softness. The special measuring catheter was made of plexiglass with two conically shaped stainless steel electrodes mounted 5 cm from its distal tip. The principle of indirect compression measurement on the basis of impedance changes between the electrodes due to the introduction of the tissue between them was tested. The changes in impedance were measured in the distal male urethra during external manual compression, and in the anal sphincter during voluntary contractions and during coughing. The results obtained confirm the applicability as well as the significance of a further perfection of the new method. Calibration technique of the transducer was developed and tested in NaCl solution. PMID:7199730

  7. Effect of wall conductivity on thermal stratification

    SciTech Connect

    Murthy, S.S.; Nelson, J.E.B.; Sitharama Rao, T.L. )

    1992-10-01

    The growing desire to find alternate energy sources to meet the ever-increasing energy demands of mankind has led to extensive research in the field of solar energy. Energy devices working on solar energy need energy storage subsystems because of the intermittent nature of solar radiation. Thermal energy storage systems which keep the warm and cold water separated by means of gravitational stratification have been found to be attractive in low and medium temperature thermal storage applications due to their simplicity and low cost. Experimental investigations have been carried out on scaled model storage tanks of various materials and wall thickness to study their effect on the stratification. It has been found that degradation of thermoclines is slower for tanks whose walls have a higher thermal resistance.

  8. Nanotubes May Break Through "Chip Wall"

    NASA Technical Reports Server (NTRS)

    Laufenberg, Larry

    2003-01-01

    In 1965, just four years after the first planar integrated circuit (IC) was discovered, Cordon Moore observed that the number of transistors per integrated circuit had grown exponentially. He predicted that this would continue, and the media soon began to call his prophesy "Moore's Law" For nearly forty years, Moore's Law has been validated by the technological progress achieved in the semiconductor industry. Now, however, industry experts are warning of a "Red Brick Wall" that may soon block the continued scaling predicted by by Moore's Law. The "red bricks" in the wall are those areas of technical challenge for which no known manufacturable solution exists. One such "brick" is the challenge of finding a new material and processing technology to replace the metals used today to interconnect transistors on a chip.

  9. Molecular discriminators using single wall carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Tamoghna; Dasgupta, Anjan Kr; Ranjan Ray, Nihar; Sarkar, Sabyasachi

    2012-09-01

    The interaction between single wall carbon nanotubes (SWNTs) and amphiphilic molecules has been studied in a solid phase. SWNTs are allowed to interact with different amphiphilic probes (e.g. lipids) in a narrow capillary interface. Contact between strong hydrophobic and amphiphilic interfaces leads to a molecular restructuring of the lipids at the interface. The geometry of the diffusion front and the rate and the extent of diffusion of the interface are dependent on the structure of the lipid at the interface. Lecithin having a linear tail showed greater mobility of the interface as compared to a branched tail lipid like dipalmitoyl phosphatidylcholine, indicating the hydrophobic interaction between single wall carbon nanotube core and the hydrophobic tail of the lipid. Solid phase interactions between SWNT and lipids can thus become a very simple but efficient means of discriminating amphiphilic molecules in general and lipids in particular.

  10. Vascular MR segmentation: wall and plaque

    NASA Astrophysics Data System (ADS)

    Yang, Fuxing; Holzapfel, Gerhard; Schulze-Bauer, Christian; Stollberger, Rudolf; Thedens, Daniel; Bolinger, Lizann; Stolpen, Alan; Sonka, Milan

    2003-05-01

    Cardiovascular events frequently result from local rupture of vulnerable atherosclerotic plaque. Non-invasive assessment of plaque vulnerability is needed to allow institution of preventive measures before heart attack or stroke occur. A computerized method for segmentation of arterial wall layers and plaque from high-resolution volumetric MR images is reported. The method uses dynamic programming to detect optimal borders in each MRI frame. The accuracy of the results was tested in 62 T1-weighted MR images from 6 vessel specimens in comparison to borders manually determined by an expert observer. The mean signed border positioning errors for the lumen, internal elastic lamina, and external elastic lamina borders were -0.12+/-0.14 mm, 0.04+/-0.12mm, and -0.15+/-0.13 mm, respectively. The presented wall layer segmentation approach is one of the first steps towards non-invasive assessment of plaque vulnerability in atherosclerotic subjects.

  11. Food applications of bacterial cell wall hydrolases.

    PubMed

    Callewaert, Lien; Walmagh, Maarten; Michiels, Chris W; Lavigne, Rob

    2011-04-01

    Bacterial cell wall hydrolases (BCWHs) display a remarkable structural and functional diversity that offers perspectives for novel food applications, reaching beyond those of the archetype BCWH and established biopreservative hen egg white lysozyme. Insights in BCWHs from bacteriophages to animals have provided concepts for tailoring BCWHs to target specific pathogens or spoilage bacteria, or, conversely, to expand their working range to Gram-negative bacteria. Genetically modified foods expressing BCWHs in situ showed successful, but face regulatory and ethical concerns. An interesting spin-off development is the use of cell wall binding domains of bacteriophage BCWHs for detection and removal of foodborne pathogens. Besides for improving food safety or stability, BCWHs may also find use as functional food ingredients with specific health effects.

  12. Cemetery perimeter wall and plantings along Wortegemseweg, looking northwest from ...

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

    Cemetery perimeter wall and plantings along Wortegemseweg, looking northwest from south corner of site. Note climbing roses on wall and shaped black locust trees. - Flanders Field American Cemetery & Memorial, Wortegemseweg 117, Waregem, West Flanders (Belgium)

  13. Correlation between spin structure oscillations and domain wall velocities

    PubMed Central

    Bisig, André; Stärk, Martin; Mawass, Mohamad-Assaad; Moutafis, Christoforos; Rhensius, Jan; Heidler, Jakoba; Büttner, Felix; Noske, Matthias; Weigand, Markus; Eisebitt, Stefan; Tyliszczak, Tolek; Van Waeyenberge, Bartel; Stoll, Hermann; Schütz, Gisela; Kläui, Mathias

    2013-01-01

    Magnetic sensing and logic devices based on the motion of magnetic domain walls rely on the precise and deterministic control of the position and the velocity of individual magnetic domain walls in curved nanowires. Varying domain wall velocities have been predicted to result from intrinsic effects such as oscillating domain wall spin structure transformations and extrinsic pinning due to imperfections. Here we use direct dynamic imaging of the nanoscale spin structure that allows us for the first time to directly check these predictions. We find a new regime of oscillating domain wall motion even below the Walker breakdown correlated with periodic spin structure changes. We show that the extrinsic pinning from imperfections in the nanowire only affects slow domain walls and we identify the magnetostatic energy, which scales with the domain wall velocity, as the energy reservoir for the domain wall to overcome the local pinning potential landscape. PMID:23978905

  14. Polarization control at spin-driven ferroelectric domain walls

    NASA Astrophysics Data System (ADS)

    Leo, Naëmi; Bergman, Anders; Cano, Andres; Poudel, Narayan; Lorenz, Bernd; Fiebig, Manfred; Meier, Dennis

    2015-04-01

    Unusual electronic states arise at ferroelectric domain walls due to the local symmetry reduction, strain gradients and electrostatics. This particularly applies to improper ferroelectrics, where the polarization is induced by a structural or magnetic order parameter. Because of the subordinate nature of the polarization, the rigid mechanical and electrostatic boundary conditions that constrain domain walls in proper ferroics are lifted. Here we show that spin-driven ferroelectricity promotes the emergence of charged domain walls. This provides new degrees of flexibility for controlling domain-wall charges in a deterministic and reversible process. We create and position a domain wall by an electric field in Mn0.95Co0.05WO4. With a magnetic field we then rotate the polarization and convert neutral into charged domain walls, while its magnetic properties peg the wall to its location. Using atomistic Landau-Lifshitz-Gilbert simulations we quantify the polarization changes across the two wall types and highlight their general occurrence.

  15. Polarization control at spin-driven ferroelectric domain walls.

    PubMed

    Leo, Naëmi; Bergman, Anders; Cano, Andres; Poudel, Narayan; Lorenz, Bernd; Fiebig, Manfred; Meier, Dennis

    2015-04-14

    Unusual electronic states arise at ferroelectric domain walls due to the local symmetry reduction, strain gradients and electrostatics. This particularly applies to improper ferroelectrics, where the polarization is induced by a structural or magnetic order parameter. Because of the subordinate nature of the polarization, the rigid mechanical and electrostatic boundary conditions that constrain domain walls in proper ferroics are lifted. Here we show that spin-driven ferroelectricity promotes the emergence of charged domain walls. This provides new degrees of flexibility for controlling domain-wall charges in a deterministic and reversible process. We create and position a domain wall by an electric field in Mn0.95Co0.05WO4. With a magnetic field we then rotate the polarization and convert neutral into charged domain walls, while its magnetic properties peg the wall to its location. Using atomistic Landau-Lifshitz-Gilbert simulations we quantify the polarization changes across the two wall types and highlight their general occurrence.

  16. Dynamical properties of the soft-wall elliptical billiard.

    PubMed

    Kroetz, Tiago; Oliveira, Hércules A; Portela, Jefferson S E; Viana, Ricardo L

    2016-08-01

    Physical systems such as optical traps and microwave cavities are realistically modeled by billiards with soft walls. In order to investigate the influence of the wall softness on the billiard dynamics, we study numerically a smooth two-dimensional potential well that has the elliptical (hard-wall) billiard as a limiting case. Considering two parameters, the eccentricity of the elliptical equipotential curves and the wall hardness, which defines the steepness of the well, we show that (1) whereas the hard-wall limit is integrable and thus completely regular, the soft wall elliptical billiard exhibits chaos, (2) the chaotic fraction of the phase space depends nonmonotonically on the hardness of the wall, and (3) the effect of the hardness on the dynamics depends strongly on the eccentricity of the billiard. We further show that the limaçon billiard can exhibit enhanced chaos induced by wall softness, which suggests that our findings generalize to quasi-integrable systems. PMID:27627309

  17. 1. View southeast from Eldred Avenue toward stone wall at ...

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

    1. View southeast from Eldred Avenue toward stone wall at corner of Benjamin Carr Farm. Wall moved to current location in 1941-1942. - Benjamin Carr Farm, Route 138 (Eldred Avenue) & Helm Street, Jamestown, Newport County, RI

  18. 14. DETAIL OF TRANSITION FROM WING WALL TO CONCRETE RETAINING ...

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

    14. DETAIL OF TRANSITION FROM WING WALL TO CONCRETE RETAINING WALL AT SOUTHERN END OF DAM - Upper Doughty Dam, 200 feet west of Garden State Parkway, 1.7 miles west of Absecon, Egg Harbor City, Atlantic County, NJ

  19. 3. North wall of pier 11 with projecting catwalks connected ...

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

    3. North wall of pier 11 with projecting catwalks connected to steel dry dock walls. - Charlestown Navy Yard, Pier 11, Charlestown Waterfront at confluence of Little Mystic Channel & Mystic River at northernmost ent of Navy Yard, Boston, Suffolk County, MA

  20. Dynamical properties of the soft-wall elliptical billiard

    NASA Astrophysics Data System (ADS)

    Kroetz, Tiago; Oliveira, Hércules A.; Portela, Jefferson S. E.; Viana, Ricardo L.

    2016-08-01

    Physical systems such as optical traps and microwave cavities are realistically modeled by billiards with soft walls. In order to investigate the influence of the wall softness on the billiard dynamics, we study numerically a smooth two-dimensional potential well that has the elliptical (hard-wall) billiard as a limiting case. Considering two parameters, the eccentricity of the elliptical equipotential curves and the wall hardness, which defines the steepness of the well, we show that (1) whereas the hard-wall limit is integrable and thus completely regular, the soft wall elliptical billiard exhibits chaos, (2) the chaotic fraction of the phase space depends nonmonotonically on the hardness of the wall, and (3) the effect of the hardness on the dynamics depends strongly on the eccentricity of the billiard. We further show that the limaçon billiard can exhibit enhanced chaos induced by wall softness, which suggests that our findings generalize to quasi-integrable systems.

  1. 32. THIRD FLOOR: DETAIL OF STENCILED MASONIC EMBLEM ON WALL ...

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

    32. THIRD FLOOR: DETAIL OF STENCILED MASONIC EMBLEM ON WALL PAPER ON SOUTHWEST WALL OF ROOM IN NORTH CORNER OF BUILDING LOOKING SOUTHWEST - Masonic Temple, 1111-1119 Eleventh Street, Altoona, Blair County, PA

  2. 4. EAST VIEW OF HEAVILY DETERIORATED SECTION OF SEA WALL ...

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

    4. EAST VIEW OF HEAVILY DETERIORATED SECTION OF SEA WALL LOOKING ACROSS ERODED EASTERN CORNER OF PEA PATCH ISLAND. BUILDING FOUNDATION REMAINS IN FOREGROUND. - Fort Delaware, Sea Wall, Pea Patch Island, Delaware City, New Castle County, DE

  3. 11. VIEW, LOOKING WESTNORTHWEST, SHOWING STRUCTURAL BREACH IN WALL CAUSED ...

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

    11. VIEW, LOOKING WEST-NORTHWEST, SHOWING STRUCTURAL BREACH IN WALL CAUSED BY MARSHY CONDITIONS. SORTED AND ASSEMBLED NATIVE BASALT COBBLES USED FOR BUILDING MATERIAL APPEAR IN BACKGROUND - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  4. 24. DETAIL VIEW OF TILE GAUGE IN INTERMEDIATE LOCK WALL, ...

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

    24. DETAIL VIEW OF TILE GAUGE IN INTERMEDIATE LOCK WALL, LOOKING NORTHEAST. NOTE STEEL WALL ARMOR EMBEDDED IN CONCRETE. - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26, Alton, Madison County, IL

  5. 6. DETAIL OF MASONRY ON SOUTHWEST WING WALL. MASONRY ON ...

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

    6. DETAIL OF MASONRY ON SOUTHWEST WING WALL. MASONRY ON WING WALLS IS LAID IN A RANDOM RUBBLE PATTERN. - Core Creek County Bridge, Spanning Core Creek, approximately 1 mile South of State Route 332 (Newtown Bypass), Newtown, Bucks County, PA

  6. 20. INTERIOR, BASEMENT, CAFETERIA, DETAIL OF LUNETTE OF EAST WALL ...

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

    20. INTERIOR, BASEMENT, CAFETERIA, DETAIL OF LUNETTE OF EAST WALL AND WALL BEHIND (4' x 5' negative; 8' x 10' print) - U.S. Department of the Interior, Eighteenth & C Streets Northwest, Washington, District of Columbia, DC

  7. 18. LOOKING EAST ALONG THIS PART OF THE NORTH WALL, ...

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

    18. LOOKING EAST ALONG THIS PART OF THE NORTH WALL, FROM A POINT ABOUT 1,500 FEET EAST OF THE FEDERAL CHANNEL MOUTH. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  8. Building America Top Innovations 2012: High-R Walls

    SciTech Connect

    none,

    2013-01-01

    This Building America Top Innovations profile describes Building America research on high-R-value walls showing the difference between rated and whole wall R values and the need for vented cladding to reduce condensation potential with some insulation types.

  9. 20. ANOTHER WATER VIEW OF THIS NORTH TRAINING WALL SECTION, ...

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

    20. ANOTHER WATER VIEW OF THIS NORTH TRAINING WALL SECTION, FROM SEVERAL HUNDRED FEET TO THE EAST OF THE PREVIOUS VIEW. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  10. Lock 1 (Savannah River Lock), Elevation of North Wall, Detail ...

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

    Lock 1 (Savannah River Lock), Elevation of North Wall, Detail of Wall Foundation, Detail of Gate Pocket - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

  11. Lock 5 View west of wing walls and chamber ...

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

    Lock 5 - View west of wing walls and chamber with gate pockets visible. Note two small notches in brick at lower portion of wing walls - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

  12. Lock 1 View north of wall west of lock ...

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

    Lock 1 - View north of wall west of lock 1. Note the wood pile and plank foundation (believed to be similar under lock 1 walls) - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

  13. At the border: the plasma membrane-cell wall continuum.

    PubMed

    Liu, Zengyu; Persson, Staffan; Sánchez-Rodríguez, Clara

    2015-03-01

    Plant cells rely on their cell walls for directed growth and environmental adaptation. Synthesis and remodelling of the cell walls are membrane-related processes. During cell growth and exposure to external stimuli, there is a constant exchange of lipids, proteins, and other cell wall components between the cytosol and the plasma membrane/apoplast. This exchange of material and the localization of cell wall proteins at certain spots in the plasma membrane seem to rely on a particular membrane composition. In addition, sensors at the plasma membrane detect changes in the cell wall architecture, and activate cytoplasmic signalling schemes and ultimately cell wall remodelling. The apoplastic polysaccharide matrix is, on the other hand, crucial for preventing proteins diffusing uncontrollably in the membrane. Therefore, the cell wall-plasma membrane link is essential for plant development and responses to external stimuli. This review focuses on the relationship between the cell wall and plasma membrane, and its importance for plant tissue organization.

  14. Detail view of Bonita Ridge Access Road Retaining Wall showing ...

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

    Detail view of Bonita Ridge Access Road Retaining Wall showing drainpipes, camera facing northwest - Fort Barry, Bonita Ridge Access Road, Retaining Wall, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  15. 15. ELEVATION VIEW OF NORTH WALL NEAR THE MIDDLE OF ...

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

    15. ELEVATION VIEW OF NORTH WALL NEAR THE MIDDLE OF THE TUNNEL SHOWING DRAINAGE GRATE AND PIPES SECURED TO THE WALL, LOOKING NORTH. - Forts Baker-Barry Tunnel, Under Lime Point Ridge on Bunker Road, Sausalito, Marin County, CA

  16. Roles of membrane trafficking in plant cell wall dynamics

    PubMed Central

    Ebine, Kazuo; Ueda, Takashi

    2015-01-01

    The cell wall is one of the characteristic components of plant cells. The cell wall composition differs among cell types and is modified in response to various environmental conditions. To properly generate and modify the cell wall, many proteins are transported to the plasma membrane or extracellular space through membrane trafficking, which is one of the key protein transport mechanisms in eukaryotic cells. Given the diverse composition and functions of the cell wall in plants, the transport of the cell wall components and proteins that are involved in cell wall-related events could be specialized for each cell type, i.e., the machinery for cell wall biogenesis, modification, and maintenance could be transported via different trafficking pathways. In this review, we summarize the recent progress in the current understanding of the roles and mechanisms of membrane trafficking in plant cells and focus on the biogenesis and regulation of the cell wall. PMID:26539200

  17. 16. MASONRY DETAIL NO. 2, NORTH TRAINING WALL, SHOWING THE ...

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

    16. MASONRY DETAIL NO. 2, NORTH TRAINING WALL, SHOWING THE RUBBLE CORE WHERE THE FACING STONES HAVE BEEN REMOVED. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  18. 6. WEST END OF NORTH TRAINING WALL, LOOKING NORTH FROM ...

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

    6. WEST END OF NORTH TRAINING WALL, LOOKING NORTH FROM THE WATER, ALSO SHOWING FOUNDATIONS FOR AN UNIDENTIFIED STRUCTURE AT RIGHT. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  19. 14. A CLOSER VIEW OF THE NORTH WALL TOP SURFACE ...

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

    14. A CLOSER VIEW OF THE NORTH WALL TOP SURFACE MASONRY, LOOKING EAST FROM A POINT NEAR THE PREVIOUS VIEW. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  20. 28. EAST END OF THE NORTH TRAINING WALL AT THE ...

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

    28. EAST END OF THE NORTH TRAINING WALL AT THE FISHING PIER, FROM THE WATER, LOOKING NORTH-NORTHEAST. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  1. 8. WEST END OF NORTH TRAINING WALL, LOOKING NORTHWEST, SHOWING ...

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

    8. WEST END OF NORTH TRAINING WALL, LOOKING NORTHWEST, SHOWING THE LIGHTHOUSE SITE OFFSHORE, AND THE UNIDENTIFIED STRUCTURE FOUNDATIONS ONSHORE AT FAR RIGHT. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  2. 19. MEDIUM DISTANCE VIEW OF NORTH TRAINING WALL FROM THE ...

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

    19. MEDIUM DISTANCE VIEW OF NORTH TRAINING WALL FROM THE WATER, LOOKING NORTH AT THE BEST EXPOSED SECTION. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  3. 175. STORAGE ROOM, SOUTH WALL OF STORAGE ROOM, ADDED WITH ...

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

    175. STORAGE ROOM, SOUTH WALL OF STORAGE ROOM, ADDED WITH ELEVATOR ADDITION OF 1905. WALL IS EXTERIOR OF ORIGINAL WAGON WORKS OF 1883. - Gruber Wagon Works, Pennsylvania Route 183 & State Hill Road at Red Bridge Park, Bernville, Berks County, PA

  4. Building D interior, looking south showing same stone wall as ...

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

    Building D interior, looking south showing same stone wall as it attaches to the east wall of Building D - Hinckley Knitting Mills, Building D, 21-35 East Wister Street, Philadelphia, Philadelphia County, PA

  5. 42. VIEW OF WALL AT EAST ENTRANCE TO WALKWAY. 'FRANK ...

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

    42. VIEW OF WALL AT EAST ENTRANCE TO WALKWAY. 'FRANK AUZA, FLAGSTAFF SHEEP CO.' SCRATCHED INTO FRESH MORTAR CAP ON STONE WALL. February 1987 - Verde River Sheep Bridge, Spanning Verde River (Tonto National Forest), Cave Creek, Maricopa County, AZ

  6. 5. Fieldstone wall along Base Line Road. View from the ...

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

    5. Fieldstone wall along Base Line Road. View from the front yard of the Pitzer-Peairs House. Decorative landscape border in foreground. - Pitzer Ranch, Rock Wall, 4353 Towne Avenue, Claremont, Los Angeles County, CA

  7. 6. Corner of fieldstone wall at Towne Avenue (right side ...

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

    6. Corner of fieldstone wall at Towne Avenue (right side of photo) and Base Line Road (background). Decorative border is also shown. - Pitzer Ranch, Rock Wall, 4353 Towne Avenue, Claremont, Los Angeles County, CA

  8. 2. Fieldstone wall along Towne Avenue. Decorative fieldstone landscape border ...

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

    2. Fieldstone wall along Towne Avenue. Decorative fieldstone landscape border is shown. Pitzer-Peairs House is in the background. - Pitzer Ranch, Rock Wall, 4353 Towne Avenue, Claremont, Los Angeles County, CA

  9. 15. INTERIOR, FIRST FLOOR, NORTHWEST ROOM, SHOWING NORTH WALL WITH ...

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

    15. INTERIOR, FIRST FLOOR, NORTHWEST ROOM, SHOWING NORTH WALL WITH DOORWAY AND EAST WALL WITH UPPER STAIRWAY - Storm King Ranger Station, U.S. Highway 101 vicinity, near Barnes Point, Port Angeles, Clallam County, WA

  10. 27. Detail of north exterior wall of taproom showing typical ...

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

    27. Detail of north exterior wall of taproom showing typical window inset in adobe wall and brackets supporting stringer and rafters. - Fort Ord, Soldiers' Club, California State Highway 1 near Eighth Street, Seaside, Monterey County, CA

  11. View of intersection with west wall of north wing and ...

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

    View of intersection with west wall of north wing and north wall of west wing; camera facing southeast. - Mare Island Naval Shipyard, Marine Prison, Suisun Avenue, west side between Mesa Road & San Pablo, Vallejo, Solano County, CA

  12. 9. May 20, 1963 SEED BUILDING FOUNDATION WALLS Under Construction. ...

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

    9. May 20, 1963 SEED BUILDING FOUNDATION WALLS Under Construction. Looking southeast showing north and west walls of Machinery Shed - Tucson Plant Material Center, Machinery Shed, 3241 North Romero Road, Tucson, Pima County, AZ

  13. Machining Thin-Walled Cylindrical Parts

    NASA Technical Reports Server (NTRS)

    Cimbak, Joe; Spagnolo, Jim; Kraus, Dan

    1988-01-01

    Cylindrical walls only few thousandths of inch thick machined accurately and without tears or punctures with aid of beryllium copper mandrel. Chilled so it contracts, then inserted in cylinder. As comes to room temperature, mandrel expands and fits snugly inside cylinder. Will not allow part to slide and provides solid backup to prevent deflection when part machined by grinding wheel. When machining finished, cylinder-and-mandrel assembly inserted in dry ice, mandrel contracts and removed from part.

  14. Stochastic behavior of nanoscale dielectric wall buckling

    NASA Astrophysics Data System (ADS)

    Friedman, Lawrence H.; Levin, Igor; Cook, Robert F.

    2016-03-01

    The random buckling patterns of nanoscale dielectric walls are analyzed using a nonlinear multi-scale stochastic method that combines experimental measurements with simulations. The dielectric walls, approximately 200 nm tall and 20 nm wide, consist of compliant, low dielectric constant (low-k) fins capped with stiff, compressively stressed TiN lines that provide the driving force for buckling. The deflections of the buckled lines exhibit sinusoidal pseudoperiodicity with amplitude fluctuation and phase decorrelation arising from stochastic variations in wall geometry, properties, and stress state at length scales shorter than the characteristic deflection wavelength of about 1000 nm. The buckling patterns are analyzed and modeled at two length scales: a longer scale (up to 5000 nm) that treats randomness as a longer-scale measurable quantity, and a shorter-scale (down to 20 nm) that treats buckling as a deterministic phenomenon. Statistical simulation is used to join the two length scales. Through this approach, the buckling model is validated and material properties and stress states are inferred. In particular, the stress state of TiN lines in three different systems is determined, along with the elastic moduli of low-k fins and the amplitudes of the small-scale random fluctuations in wall properties—all in the as-processed state. The important case of stochastic effects giving rise to buckling in a deterministically sub-critical buckling state is demonstrated. The nonlinear multiscale stochastic analysis provides guidance for design of low-k structures with acceptable buckling behavior and serves as a template for how randomness that is common to nanoscale phenomena might be measured and analyzed in other contexts.

  15. Stent implantation influence wall shear stress evolution

    NASA Astrophysics Data System (ADS)

    Bernad, S. I.; Totorean, A. F.; Bosioc, A. I.; Petre, I.; Bernad, E. S.

    2016-06-01

    Local hemodynamic factors are known affect the natural history of the restenosis critically after coronary stenting of atherosclerosis. Stent-induced flows disturbance magnitude dependent directly on the strut design. The impact of flow alterations around struts vary as the strut geometrical parameters change. Our results provide data regarding the hemodynamic parameters for the blood flow in both stenosed and stented coronary artery under physiological conditions, namely wall shear stress and pressure drop.

  16. From Cave Walls to Clay Images

    ERIC Educational Resources Information Center

    Stone, Julie

    2004-01-01

    About 15,000 BC, the bison and other animals roamed the land and cave people, in their spare time, found colorful, chalky rocks with which to play. Over the course of time, they found that the chalky rocks would rub off on the cave walls, thus cave paintings and the pursuit of art was born. This article describes one fourth-grade classroom's…

  17. Hydrogen uptake in vanadium first wall structures

    SciTech Connect

    Simonen, E.P.; Jones, R.H.

    1996-04-01

    Evaluation of hydrogen sources and transport are needed to assess the mechanical integrity of V structures. Two sources include implantation and transmutation. The proposed coatings for the DEMO and ITER first wall strongly influence retention of hydrogen isotopes. Upper limit calculations of hydrogen inventory were based on recycling to the plasma and an impermeable coolant-side coating. Hydrogen isotope concentrations in V approaching 1,000 appm may be activated.

  18. Stochastic behavior of nanoscale dielectric wall buckling

    PubMed Central

    Friedman, Lawrence H.; Levin, Igor; Cook, Robert F.

    2016-01-01

    The random buckling patterns of nanoscale dielectric walls are analyzed using a nonlinear multi-scale stochastic method that combines experimental measurements with simulations. The dielectric walls, approximately 200 nm tall and 20 nm wide, consist of compliant, low dielectric constant (low-k) fins capped with stiff, compressively stressed TiN lines that provide the driving force for buckling. The deflections of the buckled lines exhibit sinusoidal pseudoperiodicity with amplitude fluctuation and phase decorrelation arising from stochastic variations in wall geometry, properties, and stress state at length scales shorter than the characteristic deflection wavelength of about 1000 nm. The buckling patterns are analyzed and modeled at two length scales: a longer scale (up to 5000 nm) that treats randomness as a longer-scale measurable quantity, and a shorter-scale (down to 20 nm) that treats buckling as a deterministic phenomenon. Statistical simulation is used to join the two length scales. Through this approach, the buckling model is validated and material properties and stress states are inferred. In particular, the stress state of TiN lines in three different systems is determined, along with the elastic moduli of low-k fins and the amplitudes of the small-scale random fluctuations in wall properties—all in the as-processed state. The important case of stochastic effects giving rise to buckling in a deterministically sub-critical buckling state is demonstrated. The nonlinear multiscale stochastic analysis provides guidance for design of low-k structures with acceptable buckling behavior and serves as a template for how randomness that is common to nanoscale phenomena might be measured and analyzed in other contexts. PMID:27330220

  19. Hollow clay tile wall program summary report

    SciTech Connect

    Henderson, R.C.; Jones, W.D.

    1995-07-30

    Many of the Y-12 Plant buildings, constructed during the 1940s and 1950s, consist of steel ed concrete framing infilled with hollow clay tile (HCT). The infill was intended to provide for building enclosure and was not designed to have vertical or lateral load-carrying capacity. During the late 1970s and early 1980s, seismic and wind evaluations were performed on many of these buildings in conjunction with the preparation of a site-wide safety analysis report. This analytical work, based on the best available methodology, considered lateral load-carrying capacity of the HCT infill on the basis of building code allowable shear values. In parallel with the analysis effort, DOE initiated a program to develop natural phenomena capacity and performance criteria for existing buildings, but these criteria did not specify guidelines for determining the lateral force capacity of frames infilled with HCT. The evaluation of infills was, therefore, based on the provisions for the design of unreinforced masonry as outlined in standard masonry codes. When the results of the seismic and wind evaluations were compared with the new criteria, the projected building capacities fell short of the requirements. Apparently, if the buildings were to meet the new criteria, many millions of dollars would be required for building upgrades. Because the upgrade costs were significant, the assumptions and approaches used in the analyses were reevaluated. Four issues were identified: (1) Once the infilled walls cracked, what capacity (nonlinear response), if any, would the walls have to resist earthquake or wind loads applied in the plane of the infill (in-plane)? (2) Would the infilled walls remain within the steel or reinforced concrete framing when subjected to earthquake or high wind loads applied perpendicular to the infill (out-of-plane)? (3) What was the actual shear capacity of the HCT infill? (4) Was modeling the HCT infill as a shear wall the best approach?

  20. Reconstruction of full thickness chest wall defects.

    PubMed Central

    Morgan, R F; Edgerton, M T; Wanebo, H J; Daniel, T M; Spotnitz, W D; Kron, I L

    1988-01-01

    Over the last 5 years, 14 patients were treated by wide en bloc resection of chest wall tumors with primary reconstruction. There were nine females and five male patients with an age range of 31-77 years. All patients had a skeletal resection of the chest wall. An average of 3.9 ribs were resected in the patients treated. In three patients a partial sternectomy was carried out in conjunction with the rib resections. Chest wall skeletal defects were reconstructed with Prolene mesh, which was placed under tension. Soft tissue reconstruction utilized selected portions of the latissimus dorsi musculocutaneous territory with fasciocutaneous extensions beyond the muscle itself. Primary healing was obtained in all patients and secondary procedures were not required. The average hospitalization was 23 days. All patients survived the resection and reconstruction and were alive 30 days after operation. In selected patients the preservation of a portion of the innervated muscle in situ or the transfer of the muscle with the preservation of its resting length has maintained the majority of the muscle function. Images Fig. 3A. Fig. 3C. Fig. 3D. Fig. 4A. Fig. 4C. Fig. 4D. Fig. 4E. Fig. 5A. Fig. 5B. Fig. 5D. Fig. 6A. Fig. 6C. Fig. 6D. Fig. 6E. Fig. 6F. Fig. 6G. Fig. 6H. PMID:3389939

  1. Modelling the arterial wall by finite elements.

    PubMed

    Mosora, F; Harmant, A; Bernard, C; Fossion, A; Pochet, T; Juchmes, J; Cescotto, S

    1993-01-01

    The mechanical behaviour of the arterial wall was determined theoretically utilizing some parameters of blood flow measured in vivo. Continuous experimental measurements of pressure and diameter were recorded in anesthetized dogs on the thoracic ascending and midabdominal aorta. The pressure was measured by using a catheter, and the diameter firstly, at the same site, by a plethysmograph with mercury gauge and secondly, by a sonomicrometer with ferroelectric ceramic transducers. The unstressed radius and thickness were measured at the end of each experiment in situ. Considering that the viscous component is not important relatively to the nonlinear component of the elasticity and utilizing several equations for Young modulus calculation (thick and thin wall circular cylindrical tube formulas and Bergel's equation) the following values were obtained for this parameter: 0.6 MPa-2 MPa in midabdominal aorta and 2 MPa-6.5 MPa in thoracic ascending aorta. The behaviour of the aorta wall was modelled considering an elastic law and using the finite element program "Lagamine" working in large deformations. The discretized equilibrium equations are non-linear and a unique axi-symmetric, iso-parametric element of 1 cm in length with 8 knots was used for this bi-dimensional problem. The theoretical estimation of radius vessel, utilizing a constant 5 MPa Young modulus and also a variable one, are in good agreement with the experimental results, showing that this finite element model can be applied to study mechanical properties of the arteries in physiological and pathological conditions.

  2. Age dependent changes of arterial wall viscoelasticity.

    PubMed

    Antonov, P; Antonova, M; Nikolova, N; Antonova, N; Vlaskovska, M; Kasakov, L

    2008-01-01

    Viscoelastic characteristics (VEC) of old rat aorta (Wistar, 10 months) were obtained by sinusoidal excitation of intraluminal pressure (p) in cylindrical arterial preparations. The pressure excitation frequency (f(exc)) was swept in the range 3-30 Hz up and down at several mean-pressure levels while response volume oscillations were recorded and resonance curves were plotted. Natural frequency (f(0)), dynamic modulus of elasticity (E') and coefficient of viscosity (beta) were estimated from resonance curves and the dependences of VEC on p were drawn. The results showed that f(0) decreased linearly with p whereas our previous data for young rat aorta (Wistar, 4 months) showed independence of f(0) on p. E' increased nonlinearly with p with the values being higher in comparison to young rat aorta. This means stiffening of rat aorta with age in accordance with the known literature data. beta-values increased linearly with p being higher in comparison to young rat aorta, demonstrative of raised intrinsic friction in the wall. VEC values were higher at decreasing f(exc) suggesting that the direction of excitation sweeping also determines the arterial wall biomechanical behaviour. It could be concluded that blood vessels VEC worsen with age, which endangers the arterial wall integrity, especially at higher intraluminal pressure.

  3. Silo with a Corrugated Sheet Wall

    NASA Astrophysics Data System (ADS)

    Németh, Csaba; Brodniansky, Ján

    2013-09-01

    Silos and tanks are currently being used to create reserves of stored materials. Their importance is based on balancing the production and consumption of bulk materials to establish an adequate reserve throughout the year. The case study introduced within the framework of this paper focuses on thin-walled silos made of corrugated sheets and on an approach for designing these types of structures. The storage of bulk materials causes compression or tensile stresses in the walls of a silo structure. The effect of a frictional force in the silo walls creates an additional bending moment in a wave, which ultimately affects the resulting bending moments. Several mathematical and physical models were used in order to examine various types of loading and their effects on a structure. Subsequently, the accuracy of the computational models was verified by experimental measurements on a grain silo in Bojničky, Slovakia. A comparison of the experimental and mathematical models shows a reasonable match and confirms the load specifications, while indicating that the mathematical model was correct.

  4. ADVANCED HIGH PERFORMANCE SOLID WALL BLANKET CONCEPTS

    SciTech Connect

    WONG, CPC; MALANG, S; NISHIO, S; RAFFRAY, R; SAGARA, S

    2002-04-01

    OAK A271 ADVANCED HIGH PERFORMANCE SOLID WALL BLANKET CONCEPTS. First wall and blanket (FW/blanket) design is a crucial element in the performance and acceptance of a fusion power plant. High temperature structural and breeding materials are needed for high thermal performance. A suitable combination of structural design with the selected materials is necessary for D-T fuel sufficiency. Whenever possible, low afterheat, low chemical reactivity and low activation materials are desired to achieve passive safety and minimize the amount of high-level waste. Of course the selected fusion FW/blanket design will have to match the operational scenarios of high performance plasma. The key characteristics of eight advanced high performance FW/blanket concepts are presented in this paper. Design configurations, performance characteristics, unique advantages and issues are summarized. All reviewed designs can satisfy most of the necessary design goals. For further development, in concert with the advancement in plasma control and scrape off layer physics, additional emphasis will be needed in the areas of first wall coating material selection, design of plasma stabilization coils, consideration of reactor startup and transient events. To validate the projected performance of the advanced FW/blanket concepts the critical element is the need for 14 MeV neutron irradiation facilities for the generation of necessary engineering design data and the prediction of FW/blanket components lifetime and availability.

  5. Mesh Sutured Repairs of Abdominal Wall Defects

    PubMed Central

    Lanier, Steven T.; Jordan, Sumanas W.; Miller, Kyle R.; Ali, Nada A.; Stock, Stuart R.

    2016-01-01

    Background: A new closure technique is introduced, which uses strips of macroporous polypropylene mesh as a suture for closure of abdominal wall defects due to failures of standard sutures and difficulties with planar meshes. Methods: Strips of macroporous polypropylene mesh of 2 cm width were passed through the abdominal wall and tied as simple interrupted sutures. The surgical technique and surgical outcomes are presented. Results: One hundred and seven patients underwent a mesh sutured abdominal wall closure. Seventy-six patients had preoperative hernias, and the mean hernia width by CT scan for those with scans was 9.1 cm. Forty-nine surgical fields were clean-contaminated, contaminated, or dirty. Five patients had infections within the first 30 days. Only one knot was removed as an office procedure. Mean follow-up at 234 days revealed 4 recurrent hernias. Conclusions: Mesh sutured repairs reliably appose tissue under tension using concepts of force distribution and resistance to suture pull-through. The technique reduces the amount of foreign material required in comparison to sheet meshes, and avoids the shortcomings of monofilament sutures. Mesh sutured closures seem to be tolerant of bacterial contamination with low hernia recurrence rates and have replaced our routine use of mesh sheets and bioprosthetic grafts. PMID:27757361

  6. Domain wall motion in ferroelectrics: Barkhausen noise

    NASA Astrophysics Data System (ADS)

    Shur, V.; Rumyantsev, E.; Kozhevnikov, V.; Nikolaeva, E.; Shishkin, E.

    2002-03-01

    The switching current noise has been recorded during polarization reversal in single-crystalline gadolinium molybdate (GMO) and lithium tantalate (LT). Analysis of Barkhausen noise (BN) data allows to classify the noise types by determination of the critical indexes and fractal dimensions. BN is manifested as the short pulses during the polarization reversal. We have analyzed the BN data recorded in GMO and LT with various types of controlled domain structure. The data treatment in terms of probability distribution of duration, area and energy of individual pulses reveals the critical behavior typical for the fractal records in time. We used the Fourier transform and Hurst's rescaled range analysis for obtaining the Hurst factor, fractal dimension and classifying the noise types. We investigated by computer simulation the mechanism of sideways motion of 180O domain wall by nucleation at the wall taking into account the nuclei-nuclei interaction. It was shown that the moving domain walls display the fractal shape and their motion is accompanied by Flicker noise, which is in accord with experimental data. The research was made possible in part by Programs "Basic Research in Russian Universities" and "Priority Research in High School. Electronics", by Grant No. 01-02-17443 of RFBR, by Award No.REC-005 of CRDF.

  7. Space-time characteristics of wall-pressure and wall shear-stress fluctuations in wall-modeled large eddy simulation

    NASA Astrophysics Data System (ADS)

    Park, George Ilhwan; Moin, Parviz

    2016-06-01

    We report the space-time characteristics of the wall-pressure fluctuations and wall shear-stress fluctuations from wall-modeled large eddy simulation (WMLES) of a turbulent channel flow at Reτ=2000 . Two standard zonal wall models (equilibrium stress model and nonequilibrium model based on unsteady RANS) are employed, and it is shown that they yield similar results in predicting these quantities. The wall-pressure and wall shear-stress fields from WMLES are analyzed in terms of their r.m.s. fluctuations, spectra, two-point correlations, and convection velocities. It is demonstrated that the resolution requirement for predicting the wall-pressure fluctuations is more stringent than that for predicting the velocity. At least δ /Δ x >20 and δ /Δ z >30 are required to marginally resolve the integral length scales of the pressure-producing eddies near the wall. Otherwise, the pressure field is potentially aliased. Spurious high wave number modes dominate in the streamwise direction, and they contaminate the pressure spectra leading to significant overprediction of the second-order pressure statistics. When these conditions are met, the pressure statistics and spectra at low wave number or low frequency agree well with the DNS and experimental data. On the contrary, the wall shear-stress fluctuations, modeled entirely through the RANS-based wall models, are largely underpredicted and relatively insensitive to the grid resolution. The short-time, small-scale near-wall eddies, which are neither resolved nor modeled adequately in the wall models, seem to be important for accurate prediction of the wall shear-stress fluctuations.

  8. Mean flow generation in a rotating straight and sloping wall annulus with librating walls

    NASA Astrophysics Data System (ADS)

    Ghasemi V., Abouzar; Klein, Marten; Seelig, Torsten; Harlander, Uwe; Schaller, Eberhard; Will, Andreas

    2014-05-01

    The work presented is about the investigation of the mean flow generation mechanism in a rotating straight and sloping wall annulus with librating walls. Three mean flow generation mechanism may be identified: the mean flow driven by inertial wave-wave interaction, mean flow driven by the action of Reynolds stress and mean flow driven by friction. Direct numerical simulation together with a laboratory experiment is used to investigate it. An incompressible Navier-Stokes solver with the equations formulated for volume fluxes in generalized curvilinear coordinates has been used. In terms of geometry, the current investigation is divided into two parts: mean flow generation mechanism in (i) a sloping wall annulus and (ii) a straight wall annulus. For the sloping wall annulus we investigated mean flow induced by inertial wave-wave interaction and friction. Under consecutive reflections in a sloping wall annulus inertial waves may form wave attractors. It will be shown that when boundary layer over the sloping wall is centrifugally stable, a retrograde mean flow may be generated due to the focusing of inertial wave beam from the sloping wall via the inertial wave-wave interaction. In addition, we observed a prograde mean flow which is induced by the effect of friction and is scaled as a Stewartson layer. We studied the appearance of this mean flow by librating top/bottom lids and sloping wall either independently or together. A comparison with laboratory experiment (PIV) will be shown. In the second part, mean flow in a straight wall annulus induced by the effect of Reynolds stress and friction is investigated. To study mean flow generation mechanism, we allow top/bottom lids and inner and outer cylinder side walls librate either together or independently. It has been shown experimentally (Noir et al. 2010) that a retrograde mean flow in the bulk of the fluid is due to the nonlinearity of the Ekman boundary layer and instability of the Stokes boundary layer and inertial

  9. Bio-functionalization of multi-walled carbon nanotubes.

    PubMed

    Majumder, Anindya; Khazaee, Maryam; Opitz, Jörg; Beyer, Eckhard; Baraban, Larysa; Cuniberti, Gianaurelio

    2013-10-28

    Here we present a hybrid approach to functionalize multi-walled carbon nanotubes in aqueous solution, exploring a non-covalent binding strategy. We focus on formation of hybrid complexes consisting of carbon nanotubes decorated by single stranded DNA, non-covalently attached using surfactants as intermediate layers. Unlike single walled carbon nanotubes, revealing easy side wall wrapping of DNA, we observe that wrapping of nucleic acids around multi-walled carbon nanotubes is diameter dependent. PMID:24013382

  10. 12. SOUTH INSIDE FACTORY ALONG EAST WALL TO PARTS STORAGE ...

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

    12. SOUTH INSIDE FACTORY ALONG EAST WALL TO PARTS STORAGE SHELVES AND BINS OUTSIDE PARTITION WALL OF OFFICE. THE SOUTH PARTITION WALL IN THIS AREA IS FITTED WITH SHELVES COVERED WITH BOXES CONTAINING MANUSCRIPT COMPANY RECORDS. THE BENCH IN THE RIGHT FOREGROUND WAS USED FOR ATTACHING WROUGHT IRON CONNECTIONS TO THE ENDS OF WOODEN SUCKER RODS; THE WOODEN RODS WERE STORED ON THE RACKS ALONG THE EAST WALL OF THIS AREA. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  11. High Performance Walls in Hot-Dry Climates

    SciTech Connect

    Hoeschele, M.; Springer, D.; Dakin, B.; German, A.

    2015-01-01

    High performance walls represent a high priority measure for moving the next generation of new homes to the Zero Net Energy performance level. The primary goal in improving wall thermal performance revolves around increasing the wall framing from 2x4 to 2x6, adding more cavity and exterior rigid insulation, achieving insulation installation criteria meeting ENERGY STAR's thermal bypass checklist, and reducing the amount of wood penetrating the wall cavity.

  12. A counterfort versus a cantilever retaining wall - a seismic equivalence

    NASA Astrophysics Data System (ADS)

    Chugh, Ashok K.

    2005-08-01

    A procedure is presented to develop geometric dimensions and material property values for a model cantilever wall from those of a prototype counterfort wall such that the model wall will simulate the response of the prototype wall for seismic loads. The equivalency criteria are given. A sample problem is included to illustrate the use of the proposed procedure. Accuracy of results is discussed. Published in 2005 by John Wiley & Sons, Ltd.

  13. Nonlinear Behavior of RC Dual Ductility Mode Shear Walls

    NASA Astrophysics Data System (ADS)

    Labafzadeh, M. S. R.; Ziyaeifar, M.

    2008-07-01

    Shear walls are among the most common lateral load resisting systems in medium height buildings. This is due, mostly, to their ability in providing the required level of lateral stiffness and strength for the structure (with simplicity and ease). However, shear walls are not considered as efficient structural component if ductility is the major concern. The fact is, in a tall shear wall, formation of plastic hinge happen only in a fraction of the height of the wall and ductility resources of the rest of the wall remains, mostly, untapped. The experiences with coupled shear walls have shown the potential of dispersion of inelastic behavior over the height of the wall, causing more desirable ductile behavior and a better crack pattern for the whole system. Intuitively, the same concept can be extended to the shear walls with openings. In such cases, both flexural and shear ductility capacity of the system over the height of the wall can be efficiently used to provide us with a dual ductility mode shear wall. This study focuses on the role of openings in ductile behavior of shear walls. The objective of this paper is comparing the nonlinear behavior of ordinary reinforced concrete shear wall with the ones with openings. To this end, the TNO DIANA finite element software is used to show the potential of dual ductility mode of behavior in shear walls with openings. In this regards a series of inelastic static analysis on a variety of shear walls have been carried out. The results of study in a wide variety of shear walls indicate that the potential of openings in the enhancement of ductility modes of such walls in comparison with those without openings.

  14. The effect of wall friction on magnetohydrodynamic generator performance

    NASA Technical Reports Server (NTRS)

    Bishop, A. R.

    1972-01-01

    The effect of wall friction on magnetohydrodynamic generator performance is determined by introduction of a wall friction factor into the one-dimensional generator equations. This addition should be useful in improving generator analysis and determining optimum generator geometry. The curves presented can be used to determine the effects of changes in wall friction and generator performance. Wall friction has an increasing effect on the Mach number increases and a decreasing effect as the pressure drop across the generator increase.

  15. Entropy production by domain wall decay in the NMSSM

    NASA Astrophysics Data System (ADS)

    Hattori, Hironori; Kobayashi, Tatsuo; Omoto, Naoya; Seto, Osamu

    2015-11-01

    We consider domain walls in the Z3 symmetric next-to-minimal supersymmetric standard model. The spontaneous Z3 discrete symmetry breaking produces domain walls, and the stable domain walls are problematic. Thus, we assume the Z3 symmetry is slightly but explicitly broken and the domain walls decay. Such a decay causes a large late-time entropy production. We study its cosmological implications on unwanted relics such as the moduli, gravitino, lightest superparticle, and axion.

  16. Enhanced reactive metal wall for dehalogenation of hydrocarbons

    DOEpatents

    Howson, P.E.; Mackenzie, P.D.; Horney, D.P.

    1996-08-06

    A method is provided for remediation of contaminated solutions using a tiered metal wall or column. The tiered metal wall or column has at least three zones with graduated sizes of reducing metal particles. Contaminated solutions pass through the tiered wall or column to dehalogenate contaminant halogenated hydrocarbons. 3 figs.

  17. Method for limiting heat flux in double-wall tubes

    DOEpatents

    Hwang, Jaw-Yeu

    1982-01-01

    A method of limiting the heat flux in a portion of double-wall tubes including heat treating the tubes so that the walls separate when subjected to high heat flux and supplying an inert gas mixture to the gap at the interface of the double-wall tubes.

  18. 14. VIEW OF WEST WALL OF CLEAN ROOM (102) SHOWING ...

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

    14. VIEW OF WEST WALL OF CLEAN ROOM (102) SHOWING VIEWING WINDOWS IN WEST FALSE PARTION WALL, WEST WALL OF CLEAN ROOM (102), AND ROLLS OF PLASTIC WRAP FOR COVERING CLEANED FAIRING ASSEMBLY - Vandenberg Air Force Base, Space Launch Complex 3, Vehicle Support Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  19. Two endogenous proteins that induce cell wall extension in plants

    NASA Technical Reports Server (NTRS)

    McQueen-Mason, S.; Durachko, D. M.; Cosgrove, D. J.

    1992-01-01

    Plant cell enlargement is regulated by wall relaxation and yielding, which is thought to be catalyzed by elusive "wall-loosening" enzymes. By employing a reconstitution approach, we found that a crude protein extract from the cell walls of growing cucumber seedlings possessed the ability to induce the extension of isolated cell walls. This activity was restricted to the growing region of the stem and could induce the extension of isolated cell walls from various dicot stems and the leaves of amaryllidaceous monocots, but was less effective on grass coleoptile walls. Endogenous and reconstituted wall extension activities showed similar sensitivities to pH, metal ions, thiol reducing agents, proteases, and boiling in methanol or water. Sequential HPLC fractionation of the active wall extract revealed two proteins with molecular masses of 29 and 30 kD associated with the activity. Each protein, by itself, could induce wall extension without detectable hydrolytic breakdown of the wall. These proteins appear to mediate "acid growth" responses of isolated walls and may catalyze plant cell wall extension by a novel biochemical mechanism.

  20. Sound waves in two-dimensional ducts with sinusoidal walls

    NASA Technical Reports Server (NTRS)

    Nayfeh, A. H.

    1974-01-01

    The method of multiple scales is used to analyze the wave propagation in two-dimensional hard-walled ducts with sinusoidal walls. For traveling waves, resonance occurs whenever the wall wavenumber is equal to the difference of the wavenumbers of any two duct acoustic modes. The results show that neither of these resonating modes could occur without strongly generating the other.

  1. 21. A LOW TIDE VIEW OF THE NORTH TRAINING WALL'S ...

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

    21. A LOW TIDE VIEW OF THE NORTH TRAINING WALL'S CHANNEL FACING STONEWORK, LOOKING EAST FROM THE POINT WHERE MODERN RIPRAP BEGINS TO COVER THE WALL, ABOUT 2,000 FEET FROM THE WEST END. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  2. Secondary cell walls: biosynthesis, patterned deposition and transcriptional regulation.

    PubMed

    Zhong, Ruiqin; Ye, Zheng-Hua

    2015-02-01

    Secondary walls are mainly composed of cellulose, hemicelluloses (xylan and glucomannan) and lignin, and are deposited in some specialized cells, such as tracheary elements, fibers and other sclerenchymatous cells. Secondary walls provide strength to these cells, which lend mechanical support and protection to the plant body and, in the case of tracheary elements, enable them to function as conduits for transporting water. Formation of secondary walls is a complex process that requires the co-ordinated expression of secondary wall biosynthetic genes, biosynthesis and targeted secretion of secondary wall components, and patterned deposition and assembly of secondary walls. Here, we provide a comprehensive review of genes involved in secondary wall biosynthesis and deposition. Most of the genes involved in the biosynthesis of secondary wall components, including cellulose, xylan, glucomannan and lignin, have been identified and their co-ordinated activation has been shown to be mediated by a transcriptional network encompassing the secondary wall NAC and MYB master switches and their downstream transcription factors. It has been demonstrated that cortical microtubules and microtubule-associated proteins play important roles in the targeted secretion of cellulose synthase complexes, the oriented deposition of cellulose microfibrils and the patterned deposition of secondary walls. Further investigation of many secondary wall-associated genes with unknown functions will provide new insights into the mechanisms controlling the formation of secondary walls that constitute the bulk of plant biomass.

  3. Linear Stability Analysis of a Channel Flow with Porous Walls

    NASA Astrophysics Data System (ADS)

    Tilton, Nils

    2005-11-01

    This study is motivated by the extensive use of wall-transpiration in numerical studies related to inhibition and control of wall-turbulence. In general, wall-transpiration has been implemented by providing the wall-normal velocity and imposing a no-slip condition on the wall-tangential velocity. Physically, however, the pores cannot be infinitesimally small and, consequently, it is important to address how the presence of the pores affects the slip velocity at the wall and the stability of the boundary layer. Moreover, our work is motivated by the existence of only few studies on the linear stability of channels with porous walls. Our study considers a parallel-plate channel with porous walls such that a longitudinal pressure gradient induces a laminar flow in both the open channel region and the porous walls. Simplified counterparts to the Orr-Sommerfeld and Squire equations are derived for the porous regions that are valid for small permeablities. The linear stability analysis takes account of the coupling between the three disturbance fields through boundary conditions recently derived by Ochoa-Tapia and Whitaker (Int. J. Heat Mass Transfer, Vol. 38, 1995, pp 2635-2646). The resulting Orr-Sommerfeld spectrum and eigenfunctions reduce to those for Poiseuille flow as the permeability of the walls tends to zero, but are altered for greater values. We discuss symmetrical flows where parameters at both porous walls are identical as well as skewed flows where parameters at the two walls differ.

  4. The Wall of Death: Newtons, Nerves, and Nausea.

    ERIC Educational Resources Information Center

    Charoenkul, Niran; Wheeler, David; Dejasvanong, Chanwit

    1999-01-01

    Describes an experience as passengers in a car that traveled around the "Wall of Death" during a country fair show. Explains the physics behind riding vehicles around the Wall. Finds that cars don't need to lean, motorcycles must lean, and people should lean to avoid nausea while traveling around the Wall. (WRM)

  5. 14 CFR 121.247 - Fire-wall construction.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fire-wall construction. 121.247 Section 121... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.247 Fire-wall construction. Each fire wall and shroud must— (a) Be so made that no hazardous quantity of...

  6. HVI Ballistic Performance Characterization of Non-Parallel Walls

    NASA Technical Reports Server (NTRS)

    Bohl, William; Miller, Joshua; Christiansen, Eric

    2012-01-01

    The Double-Wall, "Whipple" Shield [1] has been the subject of many hypervelocity impact studies and has proven to be an effective shield system for Micro-Meteoroid and Orbital Debris (MMOD) impacts for spacecraft. The US modules of the International Space Station (ISS), with their "bumper shields" offset from their pressure holding rear walls provide good examples of effective on-orbit use of the double wall shield. The concentric cylinder shield configuration with its large radius of curvature relative to separation distance is easily and effectively represented for testing and analysis as a system of two parallel plates. The parallel plate double wall configuration has been heavily tested and characterized for shield performance for normal and oblique impacts for the ISS and other programs. The double wall shield and principally similar Stuffed Whipple Shield are very common shield types for MMOD protection. However, in some locations with many spacecraft designs, the rear wall cannot be modeled as being parallel or concentric with the outer bumper wall. As represented in Figure 1, there is an included angle between the two walls. And, with a cylindrical outer wall, the effective included angle constantly changes. This complicates assessment of critical spacecraft components located within outer spacecraft walls when using software tools such as NASA's BumperII. In addition, the validity of the risk assessment comes into question when using the standard double wall shield equations, especially since verification testing of every set of double wall included angles is impossible.

  7. 30 CFR 56.3130 - Wall, bank, and slope stability.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Wall, bank, and slope stability. 56.3130... Mining Methods § 56.3130 Wall, bank, and slope stability. Mining methods shall be used that will maintain wall, bank, and slope stability in places where persons work or travel in performing their...

  8. 30 CFR 56.3130 - Wall, bank, and slope stability.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Wall, bank, and slope stability. 56.3130... Mining Methods § 56.3130 Wall, bank, and slope stability. Mining methods shall be used that will maintain wall, bank, and slope stability in places where persons work or travel in performing their...

  9. The Berlin Wall: A Simulation for the Social Studies Classroom

    ERIC Educational Resources Information Center

    Russell, William B., III

    2010-01-01

    November 9, 2009, marked the twentieth anniversary of the opening of the Berlin Wall. The Wall, a symbol of the Cold War, separated the German people for 28 years (1961-1989), keeping those on the East side isolated. Although the construction and dismantling of the Berlin Wall is a significant part of history, the topic is little covered in the…

  10. 7. South wall of blacksmith shop section of roundhouse at ...

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

    7. South wall of blacksmith shop section of roundhouse at left. West wall and south end wall of machine shop section of roundhouse at right. View to northeast. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  11. Oblique view of Bonita Ridge Access Road Retaining Wall, showing ...

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

    Oblique view of Bonita Ridge Access Road Retaining Wall, showing southernmost portion of intact wall and portion of concrete drainage ditch from Signal Corps Radar 296 Station 5 Transmitter Building foundation above, camera facing west-north - Fort Barry, Bonita Ridge Access Road, Retaining Wall, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  12. 30 CFR 56.3131 - Pit or quarry wall perimeter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Pit or quarry wall perimeter. 56.3131 Section... Mining Methods § 56.3131 Pit or quarry wall perimeter. In places where persons work or travel in... stripped back for at least 10 feet from the top of the pit or quarry wall. Other conditions at or near...

  13. 30 CFR 56.3130 - Wall, bank, and slope stability.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Wall, bank, and slope stability. 56.3130... Mining Methods § 56.3130 Wall, bank, and slope stability. Mining methods shall be used that will maintain wall, bank, and slope stability in places where persons work or travel in performing their...

  14. 30 CFR 56.3130 - Wall, bank, and slope stability.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Wall, bank, and slope stability. 56.3130... Mining Methods § 56.3130 Wall, bank, and slope stability. Mining methods shall be used that will maintain wall, bank, and slope stability in places where persons work or travel in performing their...

  15. 30 CFR 56.3130 - Wall, bank, and slope stability.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Wall, bank, and slope stability. 56.3130... Mining Methods § 56.3130 Wall, bank, and slope stability. Mining methods shall be used that will maintain wall, bank, and slope stability in places where persons work or travel in performing their...

  16. 13. THE SAME NORTH TRAINING WALL TOP SURFACE, LOOKING EAST ...

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

    13. THE SAME NORTH TRAINING WALL TOP SURFACE, LOOKING EAST FROM ATOP ADJACENT RIPRAP. THE TRAINING WALL IS TO THE RIGHT OF THE JUMBLED, LIGHT TONED RIPRAP. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  17. 106. Photocopied August 1978. EXTENSION OF TAIL PIT WALLS, APRIL ...

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

    106. Photocopied August 1978. EXTENSION OF TAIL PIT WALLS, APRIL 28, 1917. THE TIMBERWORK IN THE FOREGROUND WAS USED AS A COMBINATION COFFER DAM AND FORM FOR POURING THE CONCRETE TAIL RACE WALL EXTENSION. IN THE BACKGROUND ALONG THE POWER HOUSE SEVERAL COMPLETED WALL EXTENSIONS CAN BE SEEN DIMLY. (787) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

  18. Enhanced reactive metal wall for dehalogenation of hydrocarbons

    DOEpatents

    Howson, Paul E.; Mackenzie, Patricia D.; Horney, David P.

    1996-01-01

    A method is provided for remediation of contaminated solutions using a tiered metal wall or column. The tiered metal wall or column has at least three zones with graduated sizes of reducing metal particles. Contaminated solutions pass through the tiered wall or column to dehalogenate contaminant halogenated hydrocarbons.

  19. 12. VIEW OF SPACE BETWEEN EAST FALSE PARTITION WALL IN ...

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

    12. VIEW OF SPACE BETWEEN EAST FALSE PARTITION WALL IN CLEAN ROOM (102) AND EAST WALL OF VEHICLE SUPPORT BUILDING SHOWING PREFILTER NEAR SOUTH WALL - Vandenberg Air Force Base, Space Launch Complex 3, Vehicle Support Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  20. Electromagnetic thin-wall model for simulations of plasma wall-touching kink and vertical modes

    NASA Astrophysics Data System (ADS)

    Zakharov, Leonid E.; Atanasiu, Calin V.; Lackner, Karl; Hoelzl, Matthias; Strumberger, Erika

    2015-12-01

    > The understanding of plasma disruptions in tokamaks and predictions of their effects require realistic simulations of electric current excitation in three-dimensional vessel structures by the plasma touching the walls. As discovered at JET in 1996 (Litunovski JET Internal Report contract no. JQ5/11961, 1995; Noll et al., Proceedings of the 19th Symposium on Fusion Technology, Lisbon (ed. C. Varandas & F. Serra), vol. 1, 1996, p. 751. Elsevier) the wall-touching kink modes are frequently excited during vertical displacement events and cause large sideways forces on the vacuum vessel which are difficult to withstand in large tokamaks. In disruptions, the sharing of electric current between the plasma and the wall plays an important role in plasma dynamics and determines the amplitude and localization of the sideways force (Riccardo et al., Nucl. Fusion, vol. 40, 2000, p. 1805; Riccardo & Walker, Plasma Phys. Control. Fusion, vol. 42, 2000, p. 29; Zakharov, Phys. Plasmas, vol. 15, 2008, 062507; Riccardo et al., Nucl. Fusion, vol. 49, 2009, 055012; Bachmann et al., Fusion Engng Des., vol. 86, 2011, pp. 1915-1919). This paper describes a flat triangle representation of the electric circuits of a thin conducting wall of arbitrary three-dimensional geometry. Implemented into the shell simulation code (SHL) and the source sink current code (SSC), this model is suitable for modelling the electric currents excited in the wall inductively and through current sharing with the plasma.

  1. FDNS code to predict wall heat fluxes or wall temperatures in rocket nozzles

    NASA Technical Reports Server (NTRS)

    Karr, Gerald R.

    1993-01-01

    This report summarizes the findings on the NASA contract NAG8-212, Task No. 3. The overall project consists of three tasks, all of which have been successfully completed. In addition, some supporting supplemental work, not required by the contract, has been performed and is documented herein. Task 1 involved the modification of the wall functions in the code FDNS to use a Reynolds Analogy-based method. Task 2 involved the verification of the code against experimentally available data. The data chosen for comparison was from an experiment involving the injection of helium from a wall jet. Results obtained in completing this task also show the sensitivity of the FDNS code to unknown conditions at the injection slot. Task 3 required computation of the flow of hot exhaust gases through the P&W 40K subscale nozzle. Computations were performed both with and without film coolant injection. The FDNS program tends to overpredict heat fluxes, but, with suitable modeling of backside cooling, may give reasonable wall temperature predictions. For film cooling in the P&W 40K calorimeter subscale nozzle, the average wall temperature is reduced from 1750 R to about 1050 R by the film cooling. The average wall heat flux is reduced by a factor of three.

  2. Effect of elasticity of wall on diffusion in nano channel

    SciTech Connect

    Tankeshwar, K.; Srivastava, Sunita

    2014-04-24

    Confining walls of nano channel are taken to be elastic to study their effect on the diffusion coefficient of fluid flowing through the channel. The wall is elastic to the extent that it responses to molecular pressure exerted by fluid. The model to study diffusion is based on microscopic considerations. Results obtained for fluid confining to 20 atomic diameter width contrasted with results obtained by considering rigid and smooth wall. The effect of roughness of wall on diffusion can be compensated by the elastic property of wall.

  3. Bent Ferroelectric Domain Walls as Reconfigurable Metallic-Like Channels.

    PubMed

    Stolichnov, Igor; Feigl, Ludwig; McGilly, Leo J; Sluka, Tomas; Wei, Xian-Kui; Colla, Enrico; Crassous, Arnaud; Shapovalov, Konstantin; Yudin, Petr; Tagantsev, Alexander K; Setter, Nava

    2015-12-01

    Use of ferroelectric domain-walls in future electronics requires that they are stable, rewritable conducting channels. Here we demonstrate nonthermally activated metallic-like conduction in nominally uncharged, bent, rewritable ferroelectric-ferroelastic domain-walls of the ubiquitous ferroelectric Pb(Zr,Ti)O3 using scanning force microscopy down to a temperature of 4 K. New walls created at 4 K by pressure exhibit similar robust and intrinsic conductivity. Atomic resolution electron energy-loss spectroscopy confirms the conductivity confinement at the wall. This work provides a new concept in "domain-wall nanoelectronics".

  4. Asymmetric error field interaction with rotating conducting walls

    SciTech Connect

    Paz-Soldan, C.; Brookhart, M. I.; Hegna, C. C.; Forest, C. B.

    2012-07-15

    The interaction of error fields with a system of differentially rotating conducting walls is studied analytically and compared to experimental data. Wall rotation causes eddy currents to persist indefinitely, attenuating and rotating the original error field. Superposition of error fields from external coils and plasma currents are found to break the symmetry in wall rotation direction. The vacuum and plasma eigenmodes are modified by wall rotation, with the error field penetration time decreased and the kink instability stabilized, respectively. Wall rotation is also predicted to reduce error field amplification by the marginally stable plasma.

  5. Ventilated wall and window test passive-solar concept

    NASA Astrophysics Data System (ADS)

    Mei, H. T.

    1982-02-01

    The ventilated wall is composed of hollow blocks through which air may flow, a duct system with a fan, and for the pre-cooled vented wall, a system for circulating well water. The performance results of the pre-cooled vent wall are briefly summarized. A vented wall and roof configuration is also described. An economic analysis of the vented wall is presented. A facility for testing the performance of window designs and configurations is described, and the effectiveness of glass, multiple glazing, reflective glass, exterior appendages and interior appliances is discussed.

  6. Wind Tunnel Wall Interference Assessment and Correction, 1983

    NASA Technical Reports Server (NTRS)

    Newman, P. A. (Editor); Barnwell, R. W. (Editor)

    1984-01-01

    Technical information focused upon emerging wall interference assessment/correction (WIAC) techniques applicable to transonic wind tunnels with conventional and passively or partially adapted walls is given. The possibility of improving the assessment and correction of data taken in conventional transonic wind tunnels by utilizing simultaneously obtained flow field data (generally taken near the walls) appears to offer a larger, nearer-term payoff than the fully adaptive wall concept. Development of WIAC procedures continues, and aspects related to validating the concept need to be addressed. Thus, the scope of wall interference topics discussed was somewhat limited.

  7. Cutting assembly including expanding wall segments of auger

    DOEpatents

    Treuhaft, Martin B.; Oser, Michael S.

    1983-01-01

    A mining auger comprises a cutting head carried at one end of a tubular shaft and a plurality of wall segments which in a first position thereof are disposed side by side around said shaft and in a second position thereof are disposed oblique to said shaft. A vane projects outwardly from each wall segment. When the wall segments are in their first position, the vanes together form a substantially continuous helical wall. A cutter is mounted on the peripheral edge of each of the vanes. When the wall segments are in their second position, the cutters on the vanes are disposed radially outward from the perimeter of the cutting head.

  8. (Hydroxyproline-rich glycoproteins of the plant cell wall)

    SciTech Connect

    Varner, J.E.

    1990-01-01

    We are studying the chemistry and architecture of plant cells walls, the extracellular matrices that taken together shape the plant and provide mechanical support for the plant. Cell walls are dynamic structures that regulate, or are the site of, many physiological processes, in addition to being the cells' first line of defense against invading pathogens. In the past year we have examined the role of the cell wall enzyme ascorbic acid oxidase as related to the structure of the wall and its possible interactions with hydroxyproline-rich glycoproteins of the wall.

  9. Wall Interference in Two-Dimensional Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Kemp, William B., Jr.

    1986-01-01

    Viscosity and tunnel-wall constraints introduced via boundary conditions. TWINTN4 computer program developed to implement method of posttest assessment of wall interference in two-dimensional wind tunnels. Offers two methods for combining sidewall boundary-layer effects with upper and lower wall interference. In sequential procedure, Sewall method used to define flow free of sidewall effects, then assessed for upper and lower wall effects. In unified procedure, wind-tunnel flow equations altered to incorporate effects from all four walls at once. Program written in FORTRAN IV for batch execution.

  10. The Layer Cake Walls of Valles Marineris

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This image of the northern wall of Coprates Chasma, in Valles Marineris, was taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) at 1227 UTC (8:27 a.m. EDT) on June 16, 2007, near 13.99 degrees south latitude, 303.09 degrees east longitude. CRISM's image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 20 meters (66 feet) across. The region covered is just over 10 kilometers (6.2 miles) wide at its narrowest point.

    Valles Marineris is a large canyon system straddling Mars' equator, with a total size approximating the Mediterranean Sea emptied of water. It is subdivided into several interconnected 'chasmata' each hundreds of kilometers wide and, in some cases, thousands of kilometers long. The walls of several of the chasmata, including Coprates Chasma, expose a section of Mars' upper crust about 5 kilometers (3 miles) in depth. Exposures like these show the layers of rock that record the formation of Mars' crust over geologic time, much as the walls of the Grand Canyon on Earth show part of our planet's history.

    The upper panel of this montage shows the location of the CRISM image on a mosaic from the Mars Odyssey spacecraft's Thermal Emission Imaging System (THEMIS), taken in longer infrared wavelengths than measured by CRISM. The CRISM image samples the base of Coprates Chasma's wall, including a conspicuous horizontal band that continues along the wall for tens of kilometers to the east and west, and a topographic shelf just above that.

    The middle two panels show the CRISM image in visible and infrared light. In the middle left panel, the red, green, and blue image planes show brightness at 0.59, 0.53, and 0.48 microns, similar to what the human eye would see. Color variations are subdued by the presence of dust on all exposed surfaces. In the middle right panel, the red, green, and blue image planes show brightness at 2.53, 1.51, and 1.08 microns. These three infrared wavelengths

  11. PREFACE: Domain wall dynamics in nanostructures Domain wall dynamics in nanostructures

    NASA Astrophysics Data System (ADS)

    Marrows, C. H.; Meier, G.

    2012-01-01

    Domain structures in magnetic materials are ubiquitous and have been studied for decades. The walls that separate them are topological defects in the magnetic order parameter and have a wide variety of complex forms. In general, their investigation is difficult in bulk materials since only the domain structure on the surface of a specimen is visible. Cutting the sample to reveal the interior causes a rearrangement of the domains into a new form. As with many other areas of magnetism, the study of domain wall physics has been revitalised by the advent of nanotechnology. The ability to fabricate nanoscale structures has permitted the formation of simplified and controlled domain patterns; the development of advanced microscopy methods has permitted them to be imaged and then modelled; subjecting them to ultrashort field and current pulses has permitted their dynamics to be explored. The latest results from all of these advances are described in this special issue. Not only has this led to results of great scientific beauty, but also to concepts of great applicability to future information technologies. In this issue the reader will find the latest results for these domain wall dynamics and the high-speed processes of topological structures such as domain walls and magnetic vortices. These dynamics can be driven by the application of magnetic fields, or by flowing currents through spintronic devices using the novel physics of spin-transfer torque. This complexity has been studied using a wide variety of experimental techniques at the edge of the spatial and temporal resolution currently available, and can be described using sophisticated analytical theory and computational modelling. As a result, the dynamics can be engineered to give rise to finely controlled memory and logic devices with new functionality. Moreover, the field is moving to study not only the conventional transition metal ferromagnets, but also complex heterostructures, novel magnets and even other

  12. Radiation Power Affected by Current and Wall Radius in Water Cooled Vortex Wall-stabilized Arc

    NASA Astrophysics Data System (ADS)

    Iwao, Toru; Nakamura, Takaya; Yanagi, Kentaro; Yamamoto, Shinji

    2015-11-01

    The arc lighting to obtain the environment to evacuate, save the life, keep the safety and be comfortable are focus on. The lack of radiation intensity and color rendering is problem because of inappropriate energy balance. Some researchers have researched the arc lamp mixed with metal vapor for improvement of color rendering spectrum. The metal vapor can emit the high intense radiation. In addition, the radiation is derived from the high temperature medium. Because the arc temperature can be controlled by current and arc radius, the radiation can be controlled by the current and arc radius. This research elucidates the radiation power affected by the current and wall radius in wall-stabilized arc of water-cooled vortex type. As a result, the radiation power increases with increasing the square of current / square of wall radius because of the temperature distribution which is derived from the current density at the simulation.

  13. Up against the wall: is yeast cell wall integrity ensured by mechanosensing in plasma membrane microdomains?

    PubMed

    Kock, Christian; Dufrêne, Yves F; Heinisch, Jürgen J

    2015-02-01

    Yeast cell wall integrity (CWI) signaling serves as a model of the regulation of fungal cell wall synthesis and provides the basis for the development of antifungal drugs. A set of five membrane-spanning sensors (Wsc1 to Wsc3, Mid2, and Mtl1) detect cell surface stress and commence the signaling pathway upon perturbations of either the cell wall structure or the plasma membrane. We here summarize the latest advances in the structure/function relationship primarily of the Wsc1 sensor and critically review the evidence that it acts as a mechanosensor. The relevance and physiological significance of the information obtained for the function of the other CWI sensors, as well as expected future developments, are discussed.

  14. Turbulent flame-wall interaction: a DNS study

    SciTech Connect

    Chen, Jackie; Hawkes, Evatt R; Sankaran, Ramanan; Gruber, Andrea

    2010-01-01

    A turbulent flame-wall interaction (FWI) configuration is studied using three-dimensional direct numerical simulation (DNS) and detailed chemical kinetics. The simulations are used to investigate the effects of the wall turbulent boundary layer (i) on the structure of a hydrogen-air premixed flame, (ii) on its near-wall propagation characteristics and (iii) on the spatial and temporal patterns of the convective wall heat flux. Results show that the local flame thickness and propagation speed vary between the core flow and the boundary layer, resulting in a regime change from flamelet near the channel centreline to a thickened flame at the wall. This finding has strong implications for the modelling of turbulent combustion using Reynolds-averaged Navier-Stokes or large-eddy simulation techniques. Moreover, the DNS results suggest that the near-wall coherent turbulent structures play an important role on the convective wall heat transfer by pushing the hot reactive zone towards the cold solid surface. At the wall, exothermic radical recombination reactions become important, and are responsible for approximately 70% of the overall heat release rate at the wall. Spectral analysis of the convective wall heat flux provides an unambiguous picture of its spatial and temporal patterns, previously unobserved, that is directly related to the spatial and temporal characteristic scalings of the coherent near-wall turbulent structures.

  15. Assembly and enlargement of the primary cell wall in plants

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.

    1997-01-01

    Growing plant cells are shaped by an extensible wall that is a complex amalgam of cellulose microfibrils bonded noncovalently to a matrix of hemicelluloses, pectins, and structural proteins. Cellulose is synthesized by complexes in the plasma membrane and is extruded as a self-assembling microfibril, whereas the matrix polymers are secreted by the Golgi apparatus and become integrated into the wall network by poorly understood mechanisms. The growing wall is under high tensile stress from cell turgor and is able to enlarge by a combination of stress relaxation and polymer creep. A pH-dependent mechanism of wall loosening, known as acid growth, is characteristic of growing walls and is mediated by a group of unusual wall proteins called expansins. Expansins appear to disrupt the noncovalent bonding of matrix hemicelluloses to the microfibril, thereby allowing the wall to yield to the mechanical forces generated by cell turgor. Other wall enzymes, such as (1-->4) beta-glucanases and pectinases, may make the wall more responsive to expansin-mediated wall creep whereas pectin methylesterases and peroxidases may alter the wall so as to make it resistant to expansin-mediated creep.

  16. Cell Wall Heterogeneity in Root Development of Arabidopsis

    PubMed Central

    Somssich, Marc; Khan, Ghazanfar Abbas; Persson, Staffan

    2016-01-01

    Plant cell walls provide stability and protection to plant cells. During growth and development the composition of cell walls changes, but provides enough strength to withstand the turgor of the cells. Hence, cell walls are highly flexible and diverse in nature. These characteristics are important during root growth, as plant roots consist of radial patterns of cells that have diverse functions and that are at different developmental stages along the growth axis. Young stem cell daughters undergo a series of rapid cell divisions, during which new cell walls are formed that are highly dynamic, and that support rapid anisotropic cell expansion. Once the cells have differentiated, the walls of specific cell types need to comply with and support different cell functions. For example, a newly formed root hair needs to be able to break through the surrounding soil, while endodermal cells modify their walls at distinct positions to form Casparian strips between them. Hence, the cell walls are modified and rebuilt while cells transit through different developmental stages. In addition, the cell walls of roots readjust to their environment to support growth and to maximize nutrient uptake. Many of these modifications are likely driven by different developmental and stress signaling pathways. However, our understanding of how such pathways affect cell wall modifications and what enzymes are involved remain largely unknown. In this review we aim to compile data linking cell wall content and re-modeling to developmental stages of root cells, and dissect how root cell walls respond to certain environmental changes. PMID:27582757

  17. Plant cell wall proteomics: the leadership of Arabidopsis thaliana

    PubMed Central

    Albenne, Cécile; Canut, Hervé; Jamet, Elisabeth

    2013-01-01

    Plant cell wall proteins (CWPs) progressively emerged as crucial components of cell walls although present in minor amounts. Cell wall polysaccharides such as pectins, hemicelluloses, and cellulose represent more than 90% of primary cell wall mass, whereas hemicelluloses, cellulose, and lignins are the main components of lignified secondary walls. All these polymers provide mechanical properties to cell walls, participate in cell shape and prevent water loss in aerial organs. However, cell walls need to be modified and customized during plant development and in response to environmental cues, thus contributing to plant adaptation. CWPs play essential roles in all these physiological processes and particularly in the dynamics of cell walls, which requires organization and rearrangements of polysaccharides as well as cell-to-cell communication. In the last 10 years, plant cell wall proteomics has greatly contributed to a wider knowledge of CWPs. This update will deal with (i) a survey of plant cell wall proteomics studies with a focus on Arabidopsis thaliana; (ii) the main protein families identified and the still missing peptides; (iii) the persistent issue of the non-canonical CWPs; (iv) the present challenges to overcome technological bottlenecks; and (v) the perspectives beyond cell wall proteomics to understand CWP functions. PMID:23641247

  18. Method of non-destructively inspecting a curved wall portion

    DOEpatents

    Fong, James T.

    1996-01-01

    A method of non-destructively inspecting a curved wall portion of a large and thick walled vessel for a defect by computed tomography is provided. A collimated source of radiation is placed adjacent one side of the wall portion and an array of detectors for the radiation is placed on the other side adjacent the source. The radiation from the source passing through the wall portion is then detected with the detectors over a limited angle, dependent upon the curvature of the wall of the vessel, to obtain a dataset. The source and array are then coordinately moved relative to the wall portion in steps and a further dataset is obtained at each step. The plurality of datasets obtained over the limited angle is then processed to produce a tomogram of the wall portion to determine the presence of a defect therein. In a preferred embodiment, the curved wall portion has a center of curvature so that the source and the array are positioned at each step along a respective arc curved about the center. If desired, the detector array and source can be reoriented relative to a new wall portion and an inspection of the new wall portion can be easily obtained. Further, the source and detector array can be indexed in a direction perpendicular to a plane including the limited angle in a plurality of steps so that by repeating the detecting and moving steps at each index step, a three dimensional image can be created of the wall portion.

  19. Morphogenesis of the Fission Yeast Cell through Cell Wall Expansion.

    PubMed

    Atilgan, Erdinc; Magidson, Valentin; Khodjakov, Alexey; Chang, Fred

    2015-08-17

    The shape of walled cells such as fungi, bacteria, and plants are determined by the cell wall. Models for cell morphogenesis postulate that the effects of turgor pressure and mechanical properties of the cell wall can explain the shapes of these diverse cell types. However, in general, these models await validation through quantitative experiments. Fission yeast Schizosaccharomyces pombe are rod-shaped cells that grow by tip extension and then divide medially through formation of a cell wall septum. Upon cell separation after cytokinesis, the new cell ends adopt a rounded morphology. Here, we show that this shape is generated by a very simple mechanical-based mechanism in which turgor pressure inflates the elastic cell wall in the absence of cell growth. This process is independent of actin and new cell wall synthesis. To model this morphological change, we first estimate the mechanical properties of the cell wall using several approaches. The lateral cell wall behaves as an isotropic elastic material with a Young's modulus of 50 ± 10 MPa inflated by a turgor pressure estimated to be 1.5 ± 0.2 MPa. Based upon these parameters, we develop a quantitative mechanical-based model for new end formation that reveals that the cell wall at the new end expands into its characteristic rounded shape in part because it is softer than the mature lateral wall. These studies provide a simple example of how turgor pressure expands the elastic cell wall to generate a particular cell shape.

  20. Cell Wall Heterogeneity in Root Development of Arabidopsis.

    PubMed

    Somssich, Marc; Khan, Ghazanfar Abbas; Persson, Staffan

    2016-01-01

    Plant cell walls provide stability and protection to plant cells. During growth and development the composition of cell walls changes, but provides enough strength to withstand the turgor of the cells. Hence, cell walls are highly flexible and diverse in nature. These characteristics are important during root growth, as plant roots consist of radial patterns of cells that have diverse functions and that are at different developmental stages along the growth axis. Young stem cell daughters undergo a series of rapid cell divisions, during which new cell walls are formed that are highly dynamic, and that support rapid anisotropic cell expansion. Once the cells have differentiated, the walls of specific cell types need to comply with and support different cell functions. For example, a newly formed root hair needs to be able to break through the surrounding soil, while endodermal cells modify their walls at distinct positions to form Casparian strips between them. Hence, the cell walls are modified and rebuilt while cells transit through different developmental stages. In addition, the cell walls of roots readjust to their environment to support growth and to maximize nutrient uptake. Many of these modifications are likely driven by different developmental and stress signaling pathways. However, our understanding of how such pathways affect cell wall modifications and what enzymes are involved remain largely unknown. In this review we aim to compile data linking cell wall content and re-modeling to developmental stages of root cells, and dissect how root cell walls respond to certain environmental changes. PMID:27582757

  1. Dynamics of domain wall driven by spin-transfer torque

    SciTech Connect

    Chureemart, P.; Evans, R. F. L.; Chantrell, R. W.

    2011-05-01

    Spin-torque switching of magnetic devices offers new technological possibilities for data storage and integrated circuits. We have investigated domain-wall motion in a ferromagnetic thin film driven by a spin-polarized current using an atomistic spin model with a modified Landau-Lifshitz-Gilbert equation including the effect of the spin-transfer torque. The presence of the spin-transfer torque is shown to create an out-of-plane domain wall, in contrast to the external-field-driven case where an in-plane wall is found. We have investigated the effect of the spin torque on domain-wall displacement, domain-wall velocity, and domain-wall width, as well as the equilibration time in the presence of the spin-transfer torque. We have shown that the minimum spin-current density, regarded as the critical value for domain-wall motion, decreases with increasing temperature.

  2. Revealing the structural and functional diversity of plant cell walls.

    PubMed

    Knox, J Paul

    2008-06-01

    The extensive knowledge of the chemistry of isolated cell wall polymers, and that relating to the identification and partial annotation of gene families involved in their synthesis and modification, is not yet matched by a sophisticated understanding of the occurrence of the polymers within cell walls of the diverse cell types within a growing organ. Currently, the main sets of tools that are used to determine cell-type-specific configurations of cell wall polymers and aspects of cell wall microstructures are antibodies, carbohydrate-binding modules (CBMs) and microspectroscopies. As these tools are applied we see that cell wall polymers are extensively developmentally regulated and that there is a range of structurally distinct primary and secondary cell walls within organs and across species. The challenge now is to document cell wall structures in relation to diverse cell biological events and to integrate this knowledge with the emerging understanding of polymer functions.

  3. Roles and regulation of plant cell walls surrounding plasmodesmata.

    PubMed

    Knox, J Paul; Benitez-Alfonso, Yoselin

    2014-12-01

    In plants, the intercellular transport of simple and complex molecules can occur symplastically through plasmodesmata. These are membranous channels embedded in cell walls that connect neighbouring cells. The properties of the cell walls surrounding plasmodesmata determine their transport capacity and permeability. These cell wall micro-domains are enriched in callose and have a characteristic pectin distribution. Cell wall modifications, leading to changes in plasmodesmata structure, have been reported to occur during development and in response to environmental signals. Cell wall remodelling enzymes target plasmodesmata to rapidly control intercellular communication in situ. Here we describe current knowledge on the composition of cell walls at plasmodesmata sites and on the proteins and signals that modify cell walls to regulate plasmodesmata aperture.

  4. A diode for ferroelectric domain-wall motion

    PubMed Central

    Whyte, J.R.; Gregg, J.M.

    2015-01-01

    For over a decade, controlling domain-wall injection, motion and annihilation along nanowires has been the preserve of the nanomagnetics research community. Revolutionary technologies have resulted, like racetrack memory and domain-wall logic. Until recently, equivalent research in analogous ferroic materials did not seem important. However, with the discovery of sheet conduction, the control of domain walls in ferroelectrics has become vital for the future of what has been termed ‘domain-wall electronics'. Here we report the creation of a ferroelectric domain-wall diode, which allows a single direction of motion for all domain walls, irrespective of their polarity, under a series of alternating electric field pulses. The diode's sawtooth morphology is central to its function. Domain walls can move readily in the direction in which thickness increases gradually, but are prevented from moving in the other direction by the sudden thickness increase at the sawtooth edge. PMID:26059779

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

    NASA Astrophysics Data System (ADS)

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

    2011-01-01

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

  6. Cell wall sorting of lipoproteins in Staphylococcus aureus.

    PubMed Central

    Navarre, W W; Daefler, S; Schneewind, O

    1996-01-01

    Many surface proteins are thought to be anchored to the cell wall of gram-positive organisms via their C termini, while the N-terminal domains of these molecules are displayed on the bacterial surface. Cell wall anchoring of surface proteins in Staphylococcus aureus requires both an N-terminal leader peptide and a C-terminal cell wall sorting signal. By fusing the cell wall sorting of protein A to the C terminus of staphylococcal beta-lactamase, we demonstrate here that lipoproteins can also be anchored to the cell wall of S. aureus. The topology of cell wall-anchored beta-lactamase is reminiscent of that described for Braun's murein lipoprotein in that the N terminus of the polypeptide chain is membrane anchored whereas the C-terminal end is tethered to the bacterial cell wall. PMID:8550464

  7. Ideal Magnetohydrodynamics Stability Spectrum with a Resistive Wall

    SciTech Connect

    S. P. Smith; Jardin, S. C.

    2008-05-01

    We show that the eigenvalue equations describing a cylindrical ideal magnetophydrodynamicsw (MHD) plasma interacting with a thin resistive wall can be put into the standard mathematical form: Α•χ = λΒ• χ. This is accomplished by using a finite element basis for the plasma, and by adding an extra degree of freedom corresponding to the electrical current in the thin wall. The standard form allows the use of linear eigenvalue solvers, without additional interations, to compute the complete spectrum of plasma modes in the presence of a surrounding restrictive wall at arbitrary separation. We show that our method recovers standard results in the limits of (1) an infinitely resistive wall (no wall), and (2) a zero resistance wall (ideal wall).

  8. A nonlinear structural concept for compliant walls. [drag reduction

    NASA Technical Reports Server (NTRS)

    Reiss, E. L.

    1982-01-01

    Two mechanisms of drag reduction for flow over flat plates were investigated. The first mechanism employs Bushnell's hypothesis that compliant walls produce drag reduction by interfering with the formation of the turbulent spots in a turbulent boundary layer. It is shown that the amplitudes and frequencies of compliant wall motions for drag reduction might be achieved by using slightly curved walls and the resulting large amplitude motions of snap buckling. A simple structural model of an arch is used in the analysis, and an asymptotic method is developed. The required wall motions can be obtained by using materials like mylar. In addition, the delay of transition from laminar to turbulent flow by driven walls was studied for Poiseuille channel flow. The walls are driven by a periodic traveling wave. A significant increase in the transitional Reynolds number is obtained by appropriately prescibing the wavelength and phase velocity of the wall motion. Previously developed asymptotic methods are used in the analysis.

  9. Compressible laminar streaks with wall suction

    NASA Astrophysics Data System (ADS)

    Ricco, Pierre; Shah, Daniel; Hicks, Peter D.

    2013-05-01

    The response of a compressible laminar boundary layer subject to free-stream vortical disturbances and steady mean-flow wall suction is studied. The theoretical frameworks of Leib et al. [J. Fluid Mech. 380, 169-203 (1999), 10.1017/S0022112098003504] and Ricco and Wu [J. Fluid Mech. 587, 97-138 (2007), 10.1017/S0022112007007070], based on the linearized unsteady boundary-region equations, are adopted to study the influence of suction on the kinematic and thermal streaks arising through the interaction between the free-stream vortical perturbations and the boundary layer. In the asymptotic limit of small spanwise wavelength compared with the boundary layer thickness, i.e., when the disturbance flow is conveniently described by the steady compressible boundary region equations, the effect of suction is mild on the velocity fluctuations and negligible on the temperature fluctuations. When the spanwise wavelength is comparable with the boundary layer thickness, small suction values intensify the supersonic streaks, while higher transpiration levels always stabilize the disturbances at all Mach numbers. At larger spanwise wavelengths, very small amplitudes of wall transpiration have a dramatic stabilizing effect on all boundary layer fluctuations, which can take the form of transiently growing thermal streaks, large amplitude streamwise oscillations, or oblique exponentially growing Tollmien-Schlichting waves, depending on the Mach number and the wavelengths. The range of wavenumbers for which the exponential growth occurs becomes narrower and the location of instability is significantly shifted downstream by mild suction, indicating that wall transpiration can be a suitable vehicle for delaying transition when the laminar breakdown is promoted by these unstable disturbances. The typical streamwise wavelength of these disturbances is instead not influenced by suction, and asymptotic triple deck theory predicts the strong changes in growth rate and the very mild

  10. Domain-wall supergravities from sphere reduction

    NASA Astrophysics Data System (ADS)

    Cvetič , M.; Liu, James T.; Lü, H.; Pope, C. N.

    1999-10-01

    Kaluza-Klein sphere reductions of supergravities that admit Ads × Sphere vacuum solutions are believed to be consistent. The examples include the S4 and S7 reductions of eleven-dimensional supergravity, and the S5 reduction of ten-dimensional type IIB supergravity . In this paper we provide evidence that sphere reductions of supergravities that admit instead Domain-wallxSphere vacuum solutions are also consistent, where the background can be viewed as the near-horizon structure of a dilatonic p-brane of the theory. The resulting lower-dimensional theory is a gauged supergravity that admits a domain wall, rather than AdS, as a vacuum solution. We illustrate this consistency by taking the singular limits of certain modulus parameters, for which the original Sn compactifying spheres ( n = 4, 5 or 7) becomes Sp × Rq, with p = n - q < n. The consistency of the S4, S7 reductions then implies the consistency of the S p reductions of the lower-dimensional supergravities. In particular, we obtain explicit non-linear ansätze for the S3 reduction of type IIA and heterotic supergravities, restricting to the U(1) 2 subgroup of the SO(4) gauge group of S3. We also study the black-hole solutions in the lower-dimensional gauged supergravities with domain-wall backgrounds. We find new domain-wall black holes which are not the singular-modulus limits of the AdS black holes of the original theories, and we obtain their Killing spinors.

  11. Computation of wall temperature and heat flux distributions of the film cooled walls

    NASA Astrophysics Data System (ADS)

    Ko, S.-Y.

    A computational algorithm and a computer program have been developed for determining the wall temperature distribution of film-cooled gas turbine flame tube. In the computer program, the Newton-Raphson iteration method is used for the solution of heat balance equation; a graphic method has been also proposed for the same purpose. Results indicate that a 1% reduction in the turbulent mixing coefficient of the combustion chamber would reduce the wall temperature by about 20 C, which would substantially increase the service life of turbine components.

  12. Optimization of multiplane μPIV for wall shear stress and wall topography characterization

    NASA Astrophysics Data System (ADS)

    Rossi, Massimiliano; Lindken, Ralph; Westerweel, Jerry

    2010-02-01

    Multiplane μPIV can be utilized to determine the wall shear stress and wall topology from the measured flow over a structured surface. A theoretical model was developed to predict the measurement error for the surface topography and shear stress, based on a theoretical analysis of the precision in PIV measurements. The main parameters that affect the accuracy of the measurement are identified. The effect of different parameter settings is studied by means of Monte Carlo simulations, and the results are compared with an experimental test case. The results are used to determine the recommended parameter settings for this measurement approach.

  13. A Fungal Endoglucanase with Plant Cell Wall Extension Activity1

    PubMed Central

    Yuan, Sheng; Wu, Yajun; Cosgrove, Daniel J.

    2001-01-01

    We have identified a wall hydrolytic enzyme from Trichoderma reesei with potent ability to induce extension of heat-inactivated type I cell walls. It is a small (23-kD) endo-1,4-β-glucanase (Cel12A) belonging to glycoside hydrolase family 12. Extension of heat-inactivated walls from cucumber (Cucumis sativus cv Burpee Pickler) hypocotyls was induced by Cel12A after a distinct lag time and was accompanied by a large increase in wall plasticity and elasticity. Cel12A also increased the rate of stress relaxation of isolated walls at very short times (<200 ms; equivalent to reducing t0, a parameter that estimates the minimum relaxation time). Similar changes in wall plasticity and elasticity were observed in wheat (Triticum aestivum cv Pennmore Winter) coleoptile (type II) walls, which showed only a negligible extension in response to Cel12A treatment. Thus, Cel12A modifies both type I and II walls, but substantial extension is found only in type I walls. Cel12A has strong endo-glucanase activity against xyloglucan and (1→3,1→4)-β-glucan, but did not exhibit endo-xylanase, endo-mannase, or endo-galactanase activities. In terms of kinetics of action and effects on wall rheology, wall loosening by Cel12A differs qualitatively from the action by expansins, which induce wall extension by a non-hydrolytic polymer creep mechanism. The action by Cel12A mimics some of the changes in wall rheology found after auxin-induced growth. The strategy used here to identify Cel12A could be used to identify analogous plant enzymes that cause auxin-induced changes in cell wall rheology. PMID:11553760

  14. Plant and algal cell walls: diversity and functionality

    PubMed Central

    Popper, Zoë A.; Ralet, Marie-Christine; Domozych, David S.

    2014-01-01

    Background Although plants and many algae (e.g. the Phaeophyceae, brown, and Rhodophyceae, red) are only very distantly related they are united in their possession of carbohydrate-rich cell walls, which are of integral importance being involved in many physiological processes. Furthermore, wall components have applications within food, fuel, pharmaceuticals, fibres (e.g. for textiles and paper) and building materials and have long been an active topic of research. As shown in the 27 papers in this Special Issue, as the major deposit of photosynthetically fixed carbon, and therefore energy investment, cell walls are of undisputed importance to the organisms that possess them, the photosynthetic eukaryotes (plants and algae). The complexities of cell wall components along with their interactions with the biotic and abiotic environment are becoming increasingly revealed. Scope The importance of plant and algal cell walls and their individual components to the function and survival of the organism, and for a number of industrial applications, are illustrated by the breadth of topics covered in this issue, which includes papers concentrating on various plants and algae, developmental stages, organs, cell wall components, and techniques. Although we acknowledge that there are many alternative ways in which the papers could be categorized (and many would fit within several topics), we have organized them as follows: (1) cell wall biosynthesis and remodelling, (2) cell wall diversity, and (3) application of new technologies to cell walls. Finally, we will consider future directions within plant cell wall research. Expansion of the industrial uses of cell walls and potentially novel uses of cell wall components are both avenues likely to direct future research activities. Fundamentally, it is the continued progression from characterization (structure, metabolism, properties and localization) of individual cell wall components through to defining their roles in almost every

  15. Geologic Structures in Crater Walls on Vesta

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, David W.; Beck, A. W.; Ammannito, E.; Carsenty, U.; DeSanctis, M. C.; LeCorre, L.; McCoy, T. J.; Reddy, V.; Schroeder, S. E.

    2012-01-01

    The Framing Camera (FC) on the Dawn spacecraft has imaged most of the illuminated surface of Vesta with a resolution of apporpx. 20 m/pixel through different wavelength filters that allow for identification of lithologic units. The Visible and Infrared Mapping Spectrometer (VIR) has imaged the surface at lower spatial resolution but high spectral resolution from 0.25 to 5 micron that allows for detailed mineralogical interpretation. The FC has imaged geologic structures in the walls of fresh craters and on scarps on the margin of the Rheasilvia basin that consist of cliff-forming, competent units, either as blocks or semi-continuous layers, hundreds of m to km below the rims. Different units have different albedos, FC color ratios and VIR spectral characteristics, and different units can be juxtaposed in individual craters. We will describe different examples of these competent units and present preliminary interpretations of the structures. A common occurrence is of blocks several hundred m in size of high albedo (bright) and low albedo (dark) materials protruding from crater walls. In many examples, dark material deposits lie below coherent bright material blocks. In FC Clementine color ratios, bright material is green indicating deeper 1 m pyroxene absorption band. VIR spectra show these to have deeper and wider 1 and 2 micron pyroxene absorption bands than the average vestan surface. The associated dark material has subdued pyroxene absorption features compared to the average vestan surface. Some dark material deposits are consistent with mixtures of HED materials with carbonaceous chondrites. This would indicate that some dark material deposits in crater walls are megabreccia blocks. The same would hold for bright material blocks found above them. Thus, these are not intact crustal units. Marcia crater is atypical in that the dark material forms a semi-continuous, thin layer immediately below bright material. Bright material occurs as one or more layers. In

  16. Resistive Wall Wakefield in the LCLS Undulator

    SciTech Connect

    Bane, Karl L.F.; Stupakov, Gennady; /SLAC

    2005-06-02

    The authors have shown that in the Linac Coherent Light Source (LCLS) undulator region, because of the high frequency content in the bunch shape, the energy variation induced by the resistive wall wake is much larger when the (proper) ac conductivity calculation is performed, than for the often-used dc calculation. Using a round copper beam pipe will result in a (relative) energy variation many times the Pierce parameter, implying that a large fraction of beam will not reach saturation. Our results suggest that this situation can be improved by, instead, choosing a flat, aluminum beam pipe.

  17. Boosting domain wall propagation by notches

    NASA Astrophysics Data System (ADS)

    Yuan, H. Y.; Wang, X. R.

    2015-08-01

    We report a counterintuitive finding that notches in an otherwise homogeneous magnetic nanowire can boost current-induced domain wall (DW) propagation. DW motion in notch-modulated wires can be classified into three phases: (1) A DW is pinned around a notch when the current density is below the depinning current density. (2) DW propagation velocity is boosted by notches above the depinning current density and when nonadiabatic spin-transfer torque strength β is smaller than the Gilbert damping constant α . The boost can be multifold. (3) DW propagation velocity is hindered when β >α . The results are explained by using the Thiele equation.

  18. Chest wall, lung, and pleural space trauma.

    PubMed

    Miller, Lisa A

    2006-03-01

    Chest radiographs frequently underestimate the severity and extent of chest trauma and, in some cases, fail to detect the presence of injury. CT is more sensitive than chest radiography in the detection of pulmonary, pleural, and osseous abnormalities in the patient who has chest trauma. With the advent of multidetector CT (MDCT), high-quality multiplanar reformations are obtained easily and add to the diagnostic capabilities of MDCT. This article reviews the radiographic and CT findings of chest wall, pleural, and pulmonary injuries that are seen in the patient who has experienced blunt thoracic trauma.

  19. STATUS OF THE DIELECTRIC WALL ACCELERATOR

    SciTech Connect

    Caporaso, G J; Chen, Y; Sampayan, S; Akana, G; Anaya, R; Blackfield, D; Carroll, J; Cook, E; Falabella, S; Guethlein, G; Harris, J; Hawkins, S; Hickman, B; Holmes, C; Horner, A; Nelson, S; Paul, A; Pearson, D; Poole, B; Richardson, R; Sanders, D; Selenes, K; Sullivan, J; Wang, L; Watson, J; Weir, J

    2009-04-22

    The dielectric wall accelerator (DWA) system being developed at the Lawrence Livermore National Laboratory (LLNL) uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. High electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The system is capable of accelerating any charge to mass ratio particle. Applications of high gradient proton and electron versions of this accelerator will be discussed. The status of the developmental new technologies that make the compact system possible will be reviewed. These include, high gradient vacuum insulators, solid dielectric materials, photoconductive switches and compact proton sources.

  20. Important considerations in chest wall reconstruction.

    PubMed

    Momeni, Arash; Kovach, Stephen J

    2016-06-01

    Chest wall reconstruction represents one of the most challenging tasks in plastic surgery. Over the past several decades, a more profound understanding of surgical anatomy and physiology along with tremendous advances in surgical technique have resulted in substantial improvements in postoperative outcomes. Conceptually, the reconstructive goals include dead space obliteration, restoration of skeletal stability with protection of intrathoracic structures, and stable soft tissue coverage. Ideally, these goals are achieved with minimal aesthetic deformity. J. Surg. Oncol. 2016;113:913-922. © 2016 Wiley Periodicals, Inc. PMID:26969557

  1. Gas turbine bucket wall thickness control

    SciTech Connect

    Stathopoulos, Dimitrios; Xu, Liming; Lewis, Doyle C.

    2002-01-01

    A core for use in casting a turbine bucket including serpentine cooling passages is divided into two pieces including a leading edge core section and a trailing edge core section. Wall thicknesses at the leading edge and the trailing edge of the turbine bucket can be controlled independent of each other by separately positioning the leading edge core section and the trailing edge core section in the casting die. The controlled leading and trailing edge thicknesses can thus be optimized for efficient cooling, resulting in more efficient turbine operation.

  2. Recurrent aggressive fibromatosis of the chest wall.

    PubMed

    Foà, Riccardo; Rizzo, Stefania; Petrella, Francesco; De Maria, Federica; Bellomi, Massimo

    2014-01-01

    A 57-year-old woman with a previous history of aesthetic surgery for breast reduction presented with a subcutaneous mass in the right axilla. A CT scan showed a solid mass on the chest wall, and she underwent surgical resection with a diagnosis of aggressive fibromatosis. After a 10-month period of follow-up, a local recurrence occurred, and in accordance with the up-to-date approach, the recurrence has been treated with a conservative approach (medical treatments) with good control of the symptoms and downsizing of the lesion.

  3. Fermion mass hierarchy from the soft wall

    SciTech Connect

    Delgado, Antonio; Diego, David

    2009-07-15

    We develop a five-dimensional model for electroweak physics based on a noncompact warped extra dimension of finite length, known as the soft wall scenario, where all the dynamical degrees of freedom propagate in the five-dimensional bulk. We solve the equations of motion and find the allowed spectra, showing that the mass of the lightest fermionic mode behaves as a power law of the effective four-dimensional Yukawa coupling constant, with the exponent being the corresponding fermionic five-dimensional bulk mass. Precisely this nonuniversal behavior allows us to reproduce the hierarchy between the standard model fermion masses (from neutrinos to the top quark) with nonhierarchical fermionic bulk masses.

  4. Low dimensional modeling of wall turbulence

    NASA Astrophysics Data System (ADS)

    Aubry, Nadine

    2015-11-01

    In this talk we will review the original low dimensional dynamical model of the wall region of a turbulent boundary layer [Aubry, Holmes, Lumley and Stone, Journal of Fluid Dynamics 192, 1988] and discuss its impact on the field of fluid dynamics. We will also invite a few researchers who would like to make brief comments on the influence Lumley had on their research paths. In collaboration with Philip Holmes, Program in Applied and Computational Mathematics and Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ.

  5. WASTE HANDLING BUILDING SHIELD WALL ANALYSIS

    SciTech Connect

    D. Padula

    2000-01-13

    The scope of this analysis is to estimate the shielding wall, ceiling or equivalent door thicknesses that will be required in the Waste Handling Building to maintain the radiation doses to personnel within acceptable limits. The shielding thickness calculated is the minimum required to meet administrative limits, and not necessarily what will be recommended for the final design. The preliminary evaluations will identify the areas which have the greatest impact on mechanical and facility design concepts. The objective is to provide the design teams with the necessary information to assure an efficient and effective design.

  6. Magnetic domain wall motion by spin transfer

    NASA Astrophysics Data System (ADS)

    Grollier, Julie; Chanthbouala, A.; Matsumoto, R.; Anane, A.; Cros, V.; Nguyen van Dau, F.; Fert, Albert

    2011-04-01

    The discovery that a spin polarized current can exert a large torque on a ferromagnet through a transfusion of spin angular momentum, offers a new way to control a magnetization by simple current injection, without the help of an applied external field. Spin transfer can be used to induce magnetization reversals and oscillations, or to control the position of a magnetic domain wall. In this review, we focus on this last mechanism, which is today the subject of an extensive research, both because the microscopic details for its origin are still debated, but also because promising applications are at stake for non-volatile magnetic memories.

  7. Constricted nanowire with stabilized magnetic domain wall

    NASA Astrophysics Data System (ADS)

    Sbiaa, R.; Al Bahri, M.

    2016-08-01

    Domain wall (DW)-based magnetic memory offers the possibility for increasing the storage capacity. However, stability of DW remains the major drawback of this scheme. In this letter, we propose a stepped nanowire for pinning DW in a desirable position. From micromagnetic simulation, the proposed design applied to in-plane magnetic anisotropy materials shows that by adjusting the nanowire step size and its width it is possible to stabilize DW for a desirable current density range. In contrast, only a movement of DW could be seen for conventional nanowire. An extension to a multi-stepped nanowire could be used for multi-bit per cell magnetic memory.

  8. The vessel wall and its interactions

    PubMed Central

    2008-01-01

    Blood cell interactions with the vessel wall were first documented almost 170 years ago. Modern advances have revealed that leukocyte and platelet interactions with the endothelium are at the nexus of complex, dynamic cellular and molecular networks that, when dysregulated, may lead to pathological inflammation and thrombosis, which are major sources of morbidity and mortality in the Western world. In this review, we relate the history of blood cell interactions with the vasculature, discuss recent progress, and raise some unresolved questions awaiting the field. PMID:18502843

  9. Effects of the Transient Blood Flow-Wall Interaction on the Wall Stress Distribution in Abdominal Aortic Aneurysm (AAA)

    NASA Astrophysics Data System (ADS)

    Tang, Rubing; Geindreau, Christian; Lasheras, Juan

    2006-11-01

    Our static finite element analysis (FEA) of both idealized and real clinical models has shown that the maximum diameter and asymmetry have substantial influence on the AAA wall stress distribution. The thrombus inside the AAA was also found to reduce the magnitude of the wall stresses. To achieve a better understanding of the wall stress distribution in real AAAs, a dynamic FEA was also performed. We considered models, both symmetric and non-symmetric, in which the aorta is assumed isotropic with nonlinear material properties. For the limiting case of rigid walls, the evolution of the flow pattern and the wall shear stresses due to fluid flow at different stages of cardiac cycle predicted by our simulations are compared with experimental results obtained in in-vitro models. A good agreement is found between both results. Finally, we have extended the analysis to the physiologically correct case of deformable walls and characterized the transient effects on the wall stresses.

  10. Growth kinetics of low temperature single-wall and few walled carbon nanotubes grown by plasma enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Gohier, A.; Minea, T. M.; Djouadi, M. A.; Jiménez, J.; Granier, A.

    2007-03-01

    Single-wall, double walled or few walled nanotubes (FWNT) are grown by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD) at temperature as low as 600 °C. Most of these structures are isolated and self-oriented perpendicular to the substrate. The growth mechanism observed for single-wall and few walled (less than seven walls) nanotubes is the “base-growth” mode. Their grow kinetics is investigated regarding two parameters namely the growth time and the synthesis temperature. It is shown that nucleation and growth rate is correlated with the number of walls into FWNT. It also provides an evidence of a critical temperature for FWNT synthesis.

  11. Inflationary power asymmetry from primordial domain walls

    SciTech Connect

    Jazayeri, Sadra; Akrami, Yashar; Firouzjahi, Hassan; Solomon, Adam R.; Wang, Yi E-mail: yashar.akrami@astro.uio.no E-mail: a.r.solomon@damtp.cam.ac.uk

    2014-11-01

    We study the asymmetric primordial fluctuations in a model of inflation in which translational invariance is broken by a domain wall. We calculate the corrections to the power spectrum of curvature perturbations; they are anisotropic and contain dipole, quadrupole, and higher multipoles with non-trivial scale-dependent amplitudes. Inspired by observations of these multipole asymmetries in terms of two-point correlations and variance in real space, we demonstrate that this model can explain the observed anomalous power asymmetry of the cosmic microwave background (CMB) sky, including its characteristic feature that the dipole dominates over higher multipoles. We test the viability of the model and place approximate constraints on its parameters by using observational values of dipole, quadrupole, and octopole amplitudes of the asymmetry measured by a local-variance estimator. We find that a configuration of the model in which the CMB sphere does not intersect the domain wall during inflation provides a good fit to the data. We further derive analytic expressions for the corrections to the CMB temperature covariance matrix, or angular power spectra, which can be used in future statistical analysis of the model in spherical harmonic space.

  12. Safer Roadside Crash Walls Would Limit Deceleration

    NASA Technical Reports Server (NTRS)

    Schneider, William C.; Locke, James P.

    2003-01-01

    The figure depicts the aspects of a proposed deceleration-limiting design for crash walls at the sides of racetracks and highways. The proposal is intended to overcome the disadvantages of both rigid barriers and kinetic-energy-absorbing barriers of prior design. Rigid barriers can keep high-speed crashing motor vehicles from leaving roadways and thereby prevent injury to nearby persons and objects, but they can also subject the occupants of the vehicles to deceleration levels high enough to cause injury or death. Kinetic-energy-absorbing barriers of prior design reduce deceleration levels somewhat, but are not designed to soften impacts optimally; moreover, some of them allow debris to bounce back onto roadways or onto roadside areas, and, in cases of glancingly incident vehicles, some of them can trap the vehicles in such a manner as to cause more injury than would occur if the vehicles were allowed to skid along the rigid barriers. The proposed crash walls would (1) allow tangentially impacting vehicles to continue sliding along the racetrack without catching them, (2) catch directly impacting vehicles to prevent them from injuring nearby persons and objects, and (3) absorb kinetic energy in a more nearly optimum way to limit decelerations to levels that human occupants could survive.

  13. Bacterial Wall as Target for Attack

    PubMed Central

    Koch, Arthur L.

    2003-01-01

    When Bacteria, Archaea, and Eucarya separated from each other, a great deal of evolution had taken place. Only then did extensive diversity arise. The bacteria split off with the new property that they had a sacculus that protected them from their own turgor pressure. The saccular wall of murein (or peptidoglycan) was an effective solution to the osmotic pressure problem, but it then was a target for other life-forms, which created lysoymes and β-lactams. The β-lactams, with their four-member strained rings, are effective agents in nature and became the first antibiotic in human medicine. But that is by no means the end of the story. Over evolutionary time, bacteria challenged by β-lactams evolved countermeasures such as β-lactamases, and the producing organisms evolved variant β-lactams. The biology of both classes became evident as the pharmaceutical industry isolated, modified, and produced new chemotherapeutic agents and as the properties of β-lactams and β-lactamases were examined by molecular techniques. This review attempts to fit the wall biology of current microbes and their clinical context into the way organisms developed on this planet as well as the changes arising since the work done by Fleming. It also outlines the scientific advances in our understanding of this broad area of biology. PMID:14557293

  14. Toxicity of single-walled carbon nanotubes.

    PubMed

    Ong, Li-Chu; Chung, Felicia Fei-Lei; Tan, Yuen-Fen; Leong, Chee-Onn

    2016-01-01

    Carbon nanotubes (CNTs) are an important class of nanomaterials, which have numerous novel properties that make them useful in technology and industry. Generally, there are two types of CNTs: single-walled nanotubes (SWNTs) and multi-walled nanotubes. SWNTs, in particular, possess unique electrical, mechanical, and thermal properties, allowing for a wide range of applications in various fields, including the electronic, computer, aerospace, and biomedical industries. However, the use of SWNTs has come under scrutiny, not only due to their peculiar nanotoxicological profile, but also due to the forecasted increase in SWNT production in the near future. As such, the risk of human exposure is likely to be increased substantially. Yet, our understanding of the toxicological risk of SWNTs in human biology remains limited. This review seeks to examine representative data on the nanotoxicity of SWNTs by first considering how SWNTs are absorbed, distributed, accumulated and excreted in a biological system, and how SWNTs induce organ-specific toxicity in the body. The contradictory findings of numerous studies with regards to the potential hazards of SWNT exposure are discussed in this review. The possible mechanisms and molecular pathways associated with SWNT nanotoxicity in target organs and specific cell types are presented. We hope that this review will stimulate further research into the fundamental aspects of CNTs, especially the biological interactions which arise due to the unique intrinsic characteristics of CNTs.

  15. Polar domain walls trigger magnetoelectric coupling

    PubMed Central

    Fontcuberta, Josep; Skumryev, Vassil; Laukhin, Vladimir; Granados, Xavier; Salje, Ekhard K. H.

    2015-01-01

    Interface physics in oxides heterostructures is pivotal in material’s science. Domain walls (DWs) in ferroic systems are examples of naturally occurring interfaces, where order parameter of neighboring domains is modified and emerging properties may develop. Here we show that electric tuning of ferroelastic domain walls in SrTiO3 leads to dramatic changes of the magnetic domain structure of a neighboring magnetic layer (La1/2Sr1/2MnO3) epitaxially clamped on a SrTiO3 substrate. We show that the properties of the magnetic layer are intimately connected to the existence of polar regions at twin boundaries of SrTiO3, developing at , that can be electrically modulated. These findings illustrate that by exploiting the responsiveness of DWs nanoregions to external stimuli, even in absence of any domain contribution, prominent and adjustable macroscopic reactions of neighboring layers can be obtained. We conclude that polar DWs, known to exist in other materials, can be used to trigger tunable responses and may lead to new ways for the manipulation of interfacial emerging properties. PMID:26387597

  16. Intense Magnetized Plasma-Wall Interaction

    SciTech Connect

    Bauer, Bruno S.; Fuelling, Stephan

    2013-11-30

    This research project studied wall-plasma interactions relevant to fusion science. Such interactions are a critical aspect of Magneto-Inertial Fusion (MIF) because flux compression by a pusher material, in particular the metal for the liner approach to MIF, involves strong eddy current heating on the surface of the pusher, and probably interactions and mixing of the pusher with the interior fuel during the time when fusion fuel is being burned. When the pusher material is a metal liner, high-energy-density conditions result in fascinating behavior. For example, "warm dense matter" is produced, for which material properties such as resistivity and opacity are not well known. In this project, the transformation into plasma of metal walls subjected to pulsed megagauss magnetic fields was studied with an experiment driven by the UNR 1 MA Zebra generator. The experiment was numerically simulated with using the MHRDR code. This simple, fundamental high-energy-density physics experiment, in a regime appropriate to MIF, has stimulated an important and fascinating comparison of numerical modeling codes and tables with experiment. In addition, we participated in developing the FRCHX experiment to compress a field-reversed-configuration (FRC) plasma with a liner, in collaboration with researchers from Air Force Research Laboratory and Los Alamos National Lab, and we helped develop diagnostics for the Plasma Liner Experiment (PLX) at LANL. Last, but not least, this project served to train students in high-energy-density physics.

  17. Volumetric Colon Wall Unfolding Using Harmonic Differentials

    PubMed Central

    Zeng, Wei; Marino, Joseph; Kaufman, Arie; Gu, Xianfeng David

    2011-01-01

    Volumetric colon wall unfolding is a novel method for virtual colon analysis and visualization with valuable applications in virtual colonoscopy (VC) and computer-aided detection (CAD) systems. A volumetrically unfolded colon enables doctors to visualize the entire colon structure without occlusions due to haustral folds, and is critical for performing efficient and accurate texture analysis on the volumetric colon wall. Though conventional colon surface flattening has been employed for these uses, volumetric colon unfolding offers the advantages of providing the needed quantities of information with needed accuracy. This work presents an efficient and effective volumetric colon unfolding method based on harmonic differentials. The colon volumes are reconstructed from CT images and are represented as tetrahedral meshes. Three harmonic 1-forms, which are linearly independent everywhere, are computed on the tetrahedral mesh. Through integration of the harmonic 1-forms, the colon volume is mapped periodically to a canonical cuboid. The method presented is automatic, simple, and practical. Experimental results are reported to show the performance of the algorithm on real medical datasets. Though applied here specifically to the colon, the method is general and can be generalized for other volumes. PMID:21765563

  18. Chiral damping in magnetic domain walls dynamics

    NASA Astrophysics Data System (ADS)

    Jué, Emilie

    Domain wall (DW) motion in materials with structural inversion asymmetry (SIA) and high spin-orbit coupling has attracted much interest in the recent years due to the discovery of unexpected physical mechanisms. Especially, it has been shown that the DW dynamics in such materials can be explained by chiral DWs with (partly or fully) Néel structure, whose stability derives from an interfacial Dzyaloshinskii-Moriya interaction (DMI). In this work, we show that DMI is not the only effect inducing chiral dynamics and demonstrate the existence of a chiral damping. This result is supported by the study of the asymmetry induced by an in-plane magnetic field on field induced domain wall motion in perpendicularly magnetized asymmetric Pt/Co/Pt trilayers. Using time reversal properties, we show that this asymmetry cannot be attributed to an effective field but originates from a purely dissipative mechanism. The observation of chiral damping, not only enriches the spectrum of physical phenomena engendered by the SIA, but since it can coexist with DMI it is essential for conceiving DW and skyrmion devices

  19. Active control of multiple resistive wall modes

    NASA Astrophysics Data System (ADS)

    Brunsell, P. R.; Yadikin, D.; Gregoratto, D.; Paccagnella, R.; Liu, Y. Q.; Bolzonella, T.; Cecconello, M.; Drake, J. R.; Kuldkepp, M.; Manduchi, G.; Marchiori, G.; Marrelli, L.; Martin, P.; Menmuir, S.; Ortolani, S.; Rachlew, E.; Spizzo, G.; Zanca, P.

    2005-12-01

    A two-dimensional array of saddle coils at Mc poloidal and Nc toroidal positions is used on the EXTRAP T2R reversed-field pinch (Brunsell P R et al 2001 Plasma Phys. Control. Fusion 43 1457) to study active control of resistive wall modes (RWMs). Spontaneous growth of several RWMs with poloidal mode number m = 1 and different toroidal mode number n is observed experimentally, in agreement with linear MHD modelling. The measured plasma response to a controlled coil field and the plasma response computed using the linear circular cylinder MHD model are in quantitive agreement. Feedback control introduces a linear coupling of modes with toroidal mode numbers n, n' that fulfil the condition |n - n'| = Nc. Pairs of coupled unstable RWMs are present in feedback experiments with an array of Mc × Nc = 4 × 16 coils. Using intelligent shell feedback, the coupled modes are generally not controlled even though the field is suppressed at the active coils. A better suppression of coupled modes may be achieved in the case of rotating modes by using the mode control feedback scheme with individually set complex gains. In feedback with a larger array of Mc × Nc = 4 × 32 coils, the coupling effect largely disappears, and with this array, the main internal RWMs n = -11, -10, +5, +6 are all simultaneously suppressed throughout the discharge (7 8 wall times). With feedback there is a two-fold extension of the pulse length, compared to discharges without feedback.

  20. [Functional Outcome after Chest Wall Stabilisation].

    PubMed

    Kyriss, T; Lenz, U; Friedel, G

    2016-09-01

    This overview reviews the current literature to compare the functional results after surgical and conservative treatment of patients with flail chest and multiple rib fractures. Regarding functional aspects, patients in the early phase after a thoracic trauma are those that benefit most from the stabilisation of the chest wall by internal fixation of the ribs. Patients recover faster from restrictive respiratory disorders, have less pain and return to the workplace earlier after an operation compared with those that receive conservative treatment. In the medium term, however, patients that are treated conservatively also achieve normal pulmonary function values and become free of pain. The period of convalescence after blunt thoracic trauma is generally underestimated. Future studies of the functional outcome after severe chest injuries should take this into account and the development of functional parameters should be monitored for at least 24 months. A prospective data collection of early and long-term surgical results in registries would be suitable to evaluate benefits and indications of chest wall stabilisation. PMID:27607891

  1. Monoclonal antibodies against plant cell wall polysaccharides

    SciTech Connect

    Hahn, M.G.; Bucheli, E.; Darvill, A.; Albersheim, P. )

    1989-04-01

    Monoclonal antibodies (McAbs) are useful tools to probe the structure of plant cell wall polysaccharides and to localize these polysaccharides in plant cells and tissues. Murine McAbs were generated against the pectic polysaccharide, rhamnogalacturonan I (RG-I), isolated from suspension-cultured sycamore cells. The McAbs that were obtained were grouped into three classes based upon their reactivities with a variety of plant polysaccharides and membrane glycoproteins. Eleven McAbs (Class I) recognize epitope(s) that appear to be immunodominant and are found in RG-I from sycamore and maize, citrus pectin, polygalacturonic acid, and membrane glycoproteins from suspension-cultured cells of sycamore, maize, tobacco, parsley, and soybean. A second group of five McAbs (Class II) recognize epitope(s) present in sycamore RG-I, but do not bind to any of the other polysaccharides or glycoproteins recognized by Class I. Lastly, one McAb (Class III) reacts with sycamore RG-I, sycamore and tamarind xyloglucan, and sycamore and rice glucuronoarabinoxylan, but does not bind to maize RG-I, polygalacturonic acid or the plant membrane glycoproteins recognized by Class I. McAbs in Classes II and III are likely to be useful in studies of the structure, biosynthesis and localization of plant cell wall polysaccharides.

  2. Plant cell wall extensibility: connecting plant cell growth with cell wall structure, mechanics, and the action of wall-modifying enzymes.

    PubMed

    Cosgrove, Daniel J

    2016-01-01

    The advent of user-friendly instruments for measuring force/deflection curves of plant surfaces at high spatial resolution has resulted in a recent outpouring of reports of the 'Young's modulus' of plant cell walls. The stimulus for these mechanical measurements comes from biomechanical models of morphogenesis of meristems and other tissues, as well as single cells, in which cell wall stress feeds back to regulate microtubule organization, auxin transport, cellulose deposition, and future growth directionality. In this article I review the differences between elastic modulus and wall extensibility in the context of cell growth. Some of the inherent complexities, assumptions, and potential pitfalls in the interpretation of indentation force/deflection curves are discussed. Reported values of elastic moduli from surface indentation measurements appear to be 10- to >1000-fold smaller than realistic tensile elastic moduli in the plane of plant cell walls. Potential reasons for this disparity are discussed, but further work is needed to make sense of the huge range in reported values. The significance of wall stress relaxation for growth is reviewed and connected to recent advances and remaining enigmas in our concepts of how cellulose, hemicellulose, and pectins are assembled to make an extensible cell wall. A comparison of the loosening action of α-expansin and Cel12A endoglucanase is used to illustrate two different ways in which cell walls may be made more extensible and the divergent effects on wall mechanics.

  3. Gastric Wall Thickness in Sleeve Gastrectomy Patients: Thickness Variation of the Gastric Wall.

    PubMed

    van Rutte, Pim W J; Naagen, Bertus J; Spek, Marinus; Jakimowicz, Jack J; Nienhuijs, Simon W

    2015-11-01

    The sleeve gastrectomy has been accepted as a primary bariatric procedure. One of the most feared complications is staple line leakage. It is important to use the right staple sizes to minimize the risk of leak. Knowledge of gastric thickness is important. The goal of this study was to measure the thickness of the gastric wall after elimination of the gastric folds in the mucosa. An electronic thickness gauge was developed that measured the anterior and posterior wall of the fresh stomach specimen together at 5 points at a pressure based on the finger pressure necessary to flatten the gastric folds. Thirty-three fresh specimens were measured. The mean compression pressure was 714 grams, and no difference was found between the 5 measure points. There was a significant difference in stomach wall thickness. The gastric antrum was more than 1 mm thicker than the fundus. No difference was found between BMI groups <40 Kg/m2, 40-50 Kg/m2, or >50 Kg/m2. No bleeding occurred, leakage occurred in 1 case. There is a significant difference in thickness of the stomach wall between the gastric fundus and the antrum. A pressure 2.5 times lower than applied in prior studies was necessary to achieve full tissue compression. Choosing thinner staple sizes for the gastric fundus might be the optimal technique for compression. However, there are several additional factors that influence the risk of staple line leaks. PMID:26680415

  4. Dynamic load test of Arquin-designed CMU wall.

    SciTech Connect

    Jensen, Richard Pearson

    2010-02-01

    The Arquin Corporation has developed a new method of constructing CMU (concrete masonry unit) walls. This new method uses polymer spacers connected to steel wires that serve as reinforcing as well as a means of accurately placing the spacers so that the concrete block can be dry stacked. The hollows of the concrete block are then filled with grout. As part of a New Mexico Small Business Assistance Program (NMSBA), Sandia National Laboratories conducted a series of tests that dynamically loaded wall segments to compare the performance of walls constructed using the Arquin method to a more traditional method of constructing CMU walls. A total of four walls were built, two with traditional methods and two with the Arquin method. Two of the walls, one traditional and one Arquin, had every third cell filled with grout. The remaining two walls, one traditional and one Arquin, had every cell filled with grout. The walls were dynamically loaded with explosive forces. No significant difference was noted between the performance of the walls constructed by the Arquin method when compared to the walls constructed by the traditional method.

  5. Cell wall, cytoskeleton, and cell expansion in higher plants.

    PubMed

    Bashline, Logan; Lei, Lei; Li, Shundai; Gu, Ying

    2014-04-01

    To accommodate two seemingly contradictory biological roles in plant physiology, providing both the rigid structural support of plant cells and the adjustable elasticity needed for cell expansion, the composition of the plant cell wall has evolved to become an intricate network of cellulosic, hemicellulosic, and pectic polysaccharides and protein. Due to its complexity, many aspects of the cell wall influence plant cell expansion, and many new and insightful observations and technologies are forthcoming. The biosynthesis of cell wall polymers and the roles of the variety of proteins involved in polysaccharide synthesis continue to be characterized. The interactions within the cell wall polymer network and the modification of these interactions provide insight into how the plant cell wall provides its dual function. The complex cell wall architecture is controlled and organized in part by the dynamic intracellular cytoskeleton and by diverse trafficking pathways of the cell wall polymers and cell wall-related machinery. Meanwhile, the cell wall is continually influenced by hormonal and integrity sensing stimuli that are perceived by the cell. These many processes cooperate to construct, maintain, and manipulate the intricate plant cell wall--an essential structure for the sustaining of the plant stature, growth, and life.

  6. Multidimensional solid-state NMR spectroscopy of plant cell walls.

    PubMed

    Wang, Tuo; Phyo, Pyae; Hong, Mei

    2016-09-01

    Plant biomass has become an important source of bio-renewable energy in modern society. The molecular structure of plant cell walls is difficult to characterize by most atomic-resolution techniques due to the insoluble and disordered nature of the cell wall. Solid-state NMR (SSNMR) spectroscopy is uniquely suited for studying native hydrated plant cell walls at the molecular level with chemical resolution. Significant progress has been made in the last five years to elucidate the molecular structures and interactions of cellulose and matrix polysaccharides in plant cell walls. These studies have focused on primary cell walls of growing plants in both the dicotyledonous and grass families, as represented by the model plants Arabidopsis thaliana, Brachypodium distachyon, and Zea mays. To date, these SSNMR results have shown that 1) cellulose, hemicellulose, and pectins form a single network in the primary cell wall; 2) in dicot cell walls, the protein expansin targets the hemicellulose-enriched region of the cellulose microfibril for its wall-loosening function; and 3) primary wall cellulose has polymorphic structures that are distinct from the microbial cellulose structures. This article summarizes these key findings, and points out future directions of investigation to advance our fundamental understanding of plant cell wall structure and function.

  7. Augmenting groundwater monitoring networks near landfills with slurry cutoff walls.

    PubMed

    Hudak, Paul F

    2004-01-01

    This study investigated the use of slurry cutoff walls in conjunction with monitoring wells to detect contaminant releases from a solid waste landfill. The 50 m wide by 75 m long landfill was oriented oblique to regional groundwater flow in a shallow sand aquifer. Computer models calculated flow fields and the detection capability of six monitoring networks, four including a 1 m wide by 50 m long cutoff wall at various positions along the landfill's downgradient boundaries and upgradient of the landfill. Wells were positioned to take advantage of convergent flow induced downgradient of the cutoff walls. A five-well network with no cutoff wall detected 81% of contaminant plumes originating within the landfill's footprint before they reached a buffer zone boundary located 50 m from the landfill's downgradient corner. By comparison, detection efficiencies of networks augmented with cutoff walls ranged from 81 to 100%. The most efficient network detected 100% of contaminant releases with four wells, with a centrally located, downgradient cutoff wall. In general, cutoff walls increased detection efficiency by delaying transport of contaminant plumes to the buffer zone boundary, thereby allowing them to increase in size, and by inducing convergent flow at downgradient areas, thereby funneling contaminant plumes toward monitoring wells. However, increases in detection efficiency were too small to offset construction costs for cutoff walls. A 100% detection efficiency was also attained by an eight-well network with no cutoff wall, at approximately one-third the cost of the most efficient wall-augmented network. PMID:15887367

  8. Magnetic domain-wall dynamics in wide permalloy strips

    NASA Astrophysics Data System (ADS)

    Estévez, Virginia; Laurson, Lasse

    2016-02-01

    Domain walls in soft permalloy strips may exhibit various equilibrium micromagnetic structures depending on the width and thickness of the strip, ranging from the well-known transverse and vortex walls in narrow and thin strips to double and triple vortex walls recently reported in wider strips [V. Estévez and L. Laurson, Phys. Rev. B 91, 054407 (2015), 10.1103/PhysRevB.91.054407]. Here, we analyze the field driven dynamics of such domain walls in permalloy strips of widths from 240 nm up to 6 μ m , using the known equilibrium domain wall structures as initial configurations. Our micromagnetic simulations show that the domain wall dynamics in wide strips is very complex, and depends strongly on the geometry of the system, as well as on the magnitude of the driving field. We discuss in detail the rich variety of the dynamical behaviors found, including dynamic transitions between different domain wall structures, periodic dynamics of a vortex core close to the strip edge, transitions towards simpler domain wall structures of the multi-vortex domain walls controlled by vortex polarity, and the fact that for some combinations of the strip geometry and the driving field the system cannot support a compact domain wall.

  9. Structural Properties and Stability of Double Walled Armchair Silicon Nanotubes

    NASA Astrophysics Data System (ADS)

    Chen, Haoliang; Ray, Asok

    2012-02-01

    A systematic study of armchair double-walled Si nanotubes (DWNT) (n,n)@(m,m) (3 <= n <= 6 ; 7 <= m <= 12) using the finite cluster approximation is presented. The geometries of the tubes have been spin optimized with an all electron 3-21G* basis set and the B3LYP functional. The study indicates that the stabilities of the double-walled Si nanotubes are of the same order as those of single-walled Si nanotubes suggesting the possibilities of experimental synthesis of both single-walled and double-walled Si nanotubes. The binding energy per atom or the cohesive energy of the double-walled nanotubes depends not only on the number of atoms but also on the coupling of the constituent single-walled nanotubes. Some nanotubes with small interlayer separations do not hold the coaxial cylindrical structure after optimization. The NTS (n, n)@(n+3, n+3) are found to have large formation energies and binding energies per atom. For example, (3,3)@(6,6), (4,4)@(7,7), (5,5)@(8,8), and (6,6)@(9,9) all have large binding energies per atom, around 3.7eV/atom. All double-walled Si nanotubes are found to be semiconductors. However, the band gap, in general, is observed to decrease from single walled nanotubes to double walled nanotubes.

  10. Soliton-dependent plasmon reflection at bilayer graphene domain walls

    NASA Astrophysics Data System (ADS)

    Jiang, Lili; Shi, Zhiwen; Zeng, Bo; Wang, Sheng; Kang, Ji-Hun; Joshi, Trinity; Jin, Chenhao; Ju, Long; Kim, Jonghwan; Lyu, Tairu; Shen, Yuen-Ron; Crommie, Michael; Gao, Hong-Jun; Wang, Feng

    2016-08-01

    Layer-stacking domain walls in bilayer graphene are emerging as a fascinating one-dimensional system that features stacking solitons structurally and quantum valley Hall boundary states electronically. The interactions between electrons in the 2D graphene domains and the one-dimensional domain-wall solitons can lead to further new quantum phenomena. Domain-wall solitons of varied local structures exist along different crystallographic orientations, which can exhibit distinct electrical, mechanical and optical properties. Here we report soliton-dependent 2D graphene plasmon reflection at different 1D domain-wall solitons in bilayer graphene using near-field infrared nanoscopy. We observe various domain-wall structures in mechanically exfoliated graphene bilayers, including network-forming triangular lattices, individual straight or bent lines, and even closed circles. The near-field infrared contrast of domain-wall solitons arises from plasmon reflection at domain walls, and exhibits markedly different behaviours at the tensile- and shear-type domain-wall solitons. In addition, the plasmon reflection at domain walls exhibits a peculiar dependence on electrostatic gating. Our study demonstrates the unusual and tunable coupling between 2D graphene plasmons and domain-wall solitons.

  11. Multidimensional solid-state NMR spectroscopy of plant cell walls.

    PubMed

    Wang, Tuo; Phyo, Pyae; Hong, Mei

    2016-09-01

    Plant biomass has become an important source of bio-renewable energy in modern society. The molecular structure of plant cell walls is difficult to characterize by most atomic-resolution techniques due to the insoluble and disordered nature of the cell wall. Solid-state NMR (SSNMR) spectroscopy is uniquely suited for studying native hydrated plant cell walls at the molecular level with chemical resolution. Significant progress has been made in the last five years to elucidate the molecular structures and interactions of cellulose and matrix polysaccharides in plant cell walls. These studies have focused on primary cell walls of growing plants in both the dicotyledonous and grass families, as represented by the model plants Arabidopsis thaliana, Brachypodium distachyon, and Zea mays. To date, these SSNMR results have shown that 1) cellulose, hemicellulose, and pectins form a single network in the primary cell wall; 2) in dicot cell walls, the protein expansin targets the hemicellulose-enriched region of the cellulose microfibril for its wall-loosening function; and 3) primary wall cellulose has polymorphic structures that are distinct from the microbial cellulose structures. This article summarizes these key findings, and points out future directions of investigation to advance our fundamental understanding of plant cell wall structure and function. PMID:27552739

  12. Thermal performance of steel-framed walls. Final report

    SciTech Connect

    Barbour, E.; Goodrow, J.; Kosny, J.; Christian, J.E.

    1994-11-21

    In wall construction, highly conductive members spaced along the wall, which allow higher heat transfer than that through less conductive areas, are referred to as thermal bridges. Thermal bridges in walls tend to increase heat loss and, under certain adverse conditions, can cause dust streaking (``ghosting``) on interior walls over studs due to temperature differentials, as well as condensation in and on walls. Although such adverse conditions can be easily avoided by proper thermal design of wall systems, these effects have not been well understood and thermal data has been lacking. Therefore, the present study was initiated to provide (1) a better understanding of the thermal behavior of steel-framed walls, (2) a set of R-values for typical wall constructions, and (3) information that could be used to develop improved methods of predicting R-values. An improved method for estimating R-value would allow an equitable comparison of thermal performance with other construction types and materials. This would increase the number of alternative materials for walls available to designers, thus allowing them to choose the optimum choice for construction. Twenty-three wall samples were tested in a calibrated hot box (ASTM C9761) to measure the thermal performance of steel-framed wall systems. The tests included an array of stud frame configurations, exterior sheathing and fiberglass batt insulations. Other studies have not included the use of insulating sheathing, which reduces the extent of the thermal bridges and improves total thermal performance. The purpose of the project was to provide measured R-values for commonly used steel-framed wall configurations and to improve R-value estimating methods. Test results were compared to R-value estimates using the parallel path method, the isothermal planes method and the ASHRAE Zone method. The comparison showed that the known procedures do not fully account for the three-dimensional effects created by steel framing in a wall.

  13. Investigation of wall bounded flows using SPH and the unified semi-analytical wall boundary conditions

    NASA Astrophysics Data System (ADS)

    Mayrhofer, Arno; Rogers, Benedict D.; Violeau, Damien; Ferrand, Martin

    2013-11-01

    Semi-analytical wall boundary conditions present a mathematically rigorous framework to prescribe the influence of solid walls in smoothed particle hydrodynamics (SPH) for fluid flows. In this paper they are investigated with respect to the skew-adjoint property which implies exact energy conservation. It will be shown that this property holds only in the limit of the continuous SPH approximation, whereas in the discrete SPH formulation it is only approximately true, leading to numerical noise. This noise, interpreted as a form of "turbulence", is treated using an additional volume diffusion term in the continuity equation which we show is equivalent to an approximate Riemann solver. Subsequently two extensions to the boundary conditions are presented. The first dealing with a variable driving force when imposing a volume flux in a periodic flow and the second showing a generalization of the wall boundary condition to Robin type and arbitrary-order interpolation. Two modifications for free-surface flows are presented for the volume diffusion term as well as the wall boundary condition. In order to validate the theoretical constructs numerical experiments are performed showing that the present volume flux term yields results with an error 5 orders of magnitude smaller then previous methods while the Robin boundary conditions are imposed correctly with an error depending on the order of the approximation. Furthermore, the proposed modifications for free-surface flows improve the behavior at the intersection of free surface and wall as well as prevent free-surface detachment when using the volume diffusion term. Finally, this paper is concluded by a simulation of a dam break over a wedge demonstrating the improvements proposed in this paper.

  14. Results of chest wall resection and reconstruction in 162 patients with benign and malignant chest wall disease

    PubMed Central

    Aghajanzadeh, Manoucheher; Alavy, Ali; Taskindost, Mehrdad; Pourrasouly, Zahra; Aghajanzadeh, Gilda; massahnia, Sara

    2010-01-01

    Background Chest wall resection is a complicated treatment modality with significant morbidity. The purpose of this study is to report our experience with chest wall resections and reconstructions. Methods The records of all patients undergoing chest wall resection and reconstruction were reviewed. Diagnostic procedures, surgical indications, the location and size of the chest wall defect, performance of lung resection, the type of prosthesis, and postoperative complications were recorded. Results From 1997 to 2008, 162 patients underwent chest wall resection.113 (70%) of patients were male. Age of patients was 14 to 69 years. The most common indications for surgery were primary chest wall tumors. The most common localized chest wall mass has been seen in the anterior chest wall. Sternal resection was required in 22 patients, Lung resection in 15 patients, Rigid prosthetic reconstruction has been used in 20 patients and nonrigid prolene mesh and Marlex mesh in 40 patients. Mean intensive care unit stay was 8 days. In-hospital mortality was 3.7 % (six patients). Conclusions Chest wall resection and reconstruction with Bone cement sandwich with mesh can be performed as a safe and effective surgical procedure for major chest wall defects and respiratory failure is lower in prosthetic reconstruction patients than previously reported (6). PMID:22263024

  15. Preparation of Cell Wall Antigens of Staphylococcus aureus

    PubMed Central

    Kowalski, J. J.; Tipper, Donald J.; Berman, David T.

    1970-01-01

    Cell walls were prepared from Staphylococcus aureus strains Copenhagen and 263 by high-speed mixing in the presence of glass beads followed by differential centrifugation. Insoluble peptidoglycan complexes were derived from cell walls by extraction of teichoic acid with 10% trichloroacetic acid. Intact teichoic acid was prepared from each strain by digestion of cell walls with lysostaphin and isolated by column chromatography. Soluble glycopeptide (peptidoglycan in which only the glycan has been fragmented) and the stable complex of teichoic acid with glycopeptide were prepared by digestion of cell walls with Chalaropsis B endo-N-acetylmuramidase and were separated by column chromatography. Amino acid and amino sugar contents of walls and subunits of walls were comparable to those reported by others. Images PMID:16557799

  16. Gallbladder wall thickness: sonographic accuracy and relation to disease.

    PubMed

    Engel, J M; Deitch, E A; Sikkema, W

    1980-05-01

    A prospective study was performed in two parts after sonographic determination of gallbladder wall thickness in 110 consecutive patients. The first part was designed to evaluate accuracy of sonographic measurements in 40 patients on whom intraoperative measurements of wall thickness were obtained. Second, the significance of wall thickness as an indicator of disease was explored by comparing the 40 surgical patients and 44 controls. Sonography was found to be accurate in determining wall thickness to within 1 mm in 93% of patients and 1.5 mm in 100%. Wall thickness greater than 3.5 mm is highly accurate in predicting disease; however, a wall thickness 3 mm or less does not rule out cholecystitis. PMID:6768264

  17. Mass spectrometry-based proteomics of fungal wall glycoproteins.

    PubMed

    Yin, Qing Yuan; de Groot, Piet W J; de Koster, Chris G; Klis, Frans M

    2008-01-01

    The manifold functions of fungal wall glycoproteins include maintenance of cell wall integrity, homotypic and heterotypic adhesion, biofilm formation, acquisition of iron and sterols, protein degradation and coping with oxidative stress. Transcriptome studies indicate that the expression levels of most cell wall glycoproteins can vary widely and are tightly controlled. However, owing to their complex and variable glycosylation, fungal wall glycoproteins are difficult to analyze using traditional proteomics approaches. Recent advances in mass spectrometry-based proteomics have enabled rapid and sensitive identification and quantitation of fungal wall glycoproteins; this will be particularly useful for studying the dynamics of the subproteome of fungal wall glycoproteins, and for the development of novel vaccines and diagnostic tools.

  18. Hollow porous-wall glass microspheres for hydrogen storage

    DOEpatents

    Heung, Leung K.; Schumacher, Ray F.; Wicks, George G.

    2010-02-23

    A porous wall hollow glass microsphere is provided having a diameter range of between 1 to 200 microns, a density of between 1.0 to 2.0 gm/cc, a porous-wall structure having wall openings defining an average pore size of between 10 to 1000 angstroms, and which contains therein a hydrogen storage material. The porous-wall structure facilitates the introduction of a hydrogen storage material into the interior of the porous wall hollow glass microsphere. In this manner, the resulting hollow glass microsphere can provide a membrane for the selective transport of hydrogen through the porous walls of the microsphere, the small pore size preventing gaseous or liquid contaminants from entering the interior of the hollow glass microsphere.

  19. Low-Reynolds-number swimming near a wall

    NASA Astrophysics Data System (ADS)

    Li, Gaojin; Ardekani, Arezoo

    2013-11-01

    Hydrodynamics of swimming organisms in a low Reynolds number regime near a no-slip wall has been a subject of growing interest in recent years because of its importance in many health and environmental problems. In addition to the changes in the swimming speed and energy expenditure of organisms in the presence of a wall, unexpected interesting swimming dynamics has been reported in recent experiments. In this study, the hydrodynamics of an archetypal low-Reynolds number swimmer, called ``squirmers,'' near a wall has been numerically studied. Depending on the swimming mechanism and swimming direction, three different modes are distinguished: (a) squirmer escaping from the wall, (b) squirmer swimming along the wall keeping a constant height and orientation angle and (c) squirmer swimming near the wall in a periodic trajectory. This work is supported by NSF Grant No. CBET-1150348-CAREER.

  20. Experimental investigation of a confined developing axisymmetric wall jet

    NASA Astrophysics Data System (ADS)

    Guo, Tianqi; Rau, Matthew; Vlachos, Pavlos; Garimella, Suresh

    2014-11-01

    The present work reports an experimental study of an axisymmetric, confined wall jet using planar particle image velocimetry (PIV) and the dielectric liquid HFE-7100. The wall jet is formed downstream from a confined and submerged impinging round jet, 3.75 mm in diameter. Both the developing region and self-similar region of the wall jet are investigated. The experiments are conducted for Reynolds numbers (Re = Ud/ υ) ranging from 1500 to 38000 and at a nozzle-to-plate spacing of four jet diameters. Image-preprocessing techniques are used to eliminate background noise and an ensemble correlation scheme is applied to improve the resolution of the measurement of the mean velocity field near the wall. A maximum measurement resolution of 36 μm is achieved. Profiles of the mean velocity, turbulent intensities, decay rate, spread rate and wall shear stress are used to characterize the influence of confinement on the wall jet development and inner layer scaling.