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Sample records for arch equilibrium estabilidade

  1. Siphon flows in isolated magnetic flux tubes. 3: The equilibrium path of the flux tube arch

    NASA Technical Reports Server (NTRS)

    Thomas, John H.; Montesinis, Benjamin

    1989-01-01

    The arched equilibrium path of a thin magnetic flux tube in a plane-stratified, nonmagnetic atmosphere is calculated for cases in which the flux tube contains a steady siphon flow. The large scale mechanical equilibrium of the flux tube involves a balance among the magnetic buoyancy force, the net magnetic tension force due to the curvature of the flux tube axis, and the inertial (centrifugal) force due to the siphon flow along curved streamlines. The ends of the flux tube are assumed to be pinned down by some other external force. Both isothermal and adiabatic siphon flows are considered for flux tubes in an isothermal external atmosphere. For the isothermal case, in the absence of a siphon flow the equilibrium path reduces to the static arch calculated by Parker (1975, 1979). The presence of a siphon flow causes the flux tube arch to bend more sharply, so that magnetic tension can overcome the additional straightening effect of the inertial force, and reduces the maximum width of the arch. The curvature of the arch increases as the siphon flow speed increases. For a critical siphon flow, with supercritical flow in the downstream leg, the arch is asymmetric, with greater curvature in the downstream leg of the arch. Adiabatic flow have qualitatively similar effects, except that adiabatic cooling reduces the buoyancy of the flux tube and thus leads to significantly wider arches. In some cases the cooling is strong enough to create negative buoyancy along sections of the flux tube, requiring upward curvature of the flux tube path along these sections and sometimes leading to unusual equilibrium paths of periodic, sinusoidal form.

  2. Siphon flows in isolated magnetic flux tubes. III - The equilibrium path of the flux-tube arch

    NASA Technical Reports Server (NTRS)

    Thomas, John H.; Montesinos, Benjamin

    1990-01-01

    It is shown how to calculate the equilibrium path of a thin magnetic flux tube in a stratified, nonmagnetic atmosphere when the flux tube contains a steady siphon flow. The equilbrium path of a static thin flux tube in an infinite stratified atmosphere generally takes the form of a symmetric arch of finite width, with the flux tube becoming vertical at either end of the arch. A siphon flow within the flux tube increases the curvature of the arched equilibrium path in order that the net magnetic tension force can balance the inertial force of the flow, which tries to straighten the flux tube. Thus, a siphon flow reduces the width of the arched equilibrium path, with faster flows producing narrower arches. The effect of the siphon flow on the equilibrium path is generally greater for flux tubes of weaker magnetic field strength. Examples of the equilibrium are shown for both isothemal and adiabatic siphon flows in thin flux tubes in an isothermal external atmosphere.

  3. High arch

    MedlinePlus

    Pes cavus; High foot arch ... High foot arches are much less common than flat feet. They are more likely to be caused by a ... stress is placed on the section of the foot between the ankle and toes (metatarsals). This condition ...

  4. High arch

    MedlinePlus

    ... is on the back and balls of the foot (metatarsals head). Your health care provider will check to see if the high ... Call your health care provider if you suspect you are having foot pain related to high arches.

  5. Arching Solar Prominence

    NASA Video Gallery

    NASA’s STEREO (Ahead) spacecraft watched as an eruptive prominence rose up and arched out in a horseshoe shape far above the Sun’s surface (Aug. 25, 2010). The image and movie show the action in a...

  6. Double aortic arch

    MedlinePlus

    ... double aortic arch may press on the windpipe (trachea) and esophagus, leading to trouble breathing and swallowing. ... to relieve pressure on the esophagus and windpipe (trachea). The surgeon ties off the smaller branch and ...

  7. 18. Understructure, view of south arch abutment showing arch ribs, ...

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

    18. Understructure, view of south arch abutment showing arch ribs, columns, sway bracing, floor beams, deck cantilever, railing; view to southwest. - Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

  8. 9. DETAIL OF EAST ARCH, FROM ROADWAY, SHOWING ARCH RIB, ...

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

    9. DETAIL OF EAST ARCH, FROM ROADWAY, SHOWING ARCH RIB, ARTICULATED HANGER AND GUARDRAIL. VIEW TO SOUTHEAST. - Rock Valley Bridge, Spanning North Timber Creek at Old U.S. Highway 30, Marshalltown, Marshall County, IA

  9. 10. DETAIL OF WEST ARCH, FROM ROADWAY, SHOWING ARCH RIB, ...

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

    10. DETAIL OF WEST ARCH, FROM ROADWAY, SHOWING ARCH RIB, HANGERS AND GUARDRAIL. VIEW TO SOUTH. - Rock Valley Bridge, Spanning North Timber Creek at Old U.S. Highway 30, Marshalltown, Marshall County, IA

  10. BRIDGE ABUTMENTS WITH ARCH SEGMENTS ON RIVER BOTTOM. ARCHES COLLAPSED ...

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

    BRIDGE ABUTMENTS WITH ARCH SEGMENTS ON RIVER BOTTOM. ARCHES COLLAPSED AROUND EIGHT YEARS BEFORE THIS DATE. - Whittlesey Road Bridge, Spanning Black River at Whittlesey Road, Lyons Falls, Lewis County, NY

  11. Dental Arch Wire

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Straightening teeth is an arduous process requiring months, often years, of applying corrective pressure by means of arch wires-better known as brace-which may have to be changed several times in the course of treatment. A new method has been developed by Dr. George Andreasen, orthodontist and dental scientist at the University of Iowa. The key is a new type of arch wire material, called Nitinol, with exceptional elasticity which helps reduce the required number of brace changes. An alloy of nickel and titanium, Nitinol was originally developed for aerospace applications by the Naval Ordnance Laboratory, now the Naval Surface Weapons Laboratory, White Oaks, Maryland. NASA subsequently conducted additional research on the properties of Nitinol and on procedures for processing the metal.

  12. Burmese Arched Harp

    NASA Astrophysics Data System (ADS)

    Williamson, Robert M.

    Our knowledge of the history, construction, and tunings of the Burmese arched harp (saùng gauk) comes from a variety of sources. Conversations with master harpists, together with recordings made of their performances between 1960 and 1980, provide richly detailed examples of the effect of Western music on a non-Western musical tradition. Scholars' essays and conference proceedings complement these first-hand accounts, expanding our understanding of Burmese music and musical instruments.

  13. Greater arch injuries.

    PubMed

    Shivanna, Deepak; Manjunath, Dayanand; Amaravathi, Rajkumar

    2014-12-01

    Dislocations and fracture dislocations of carpal bones are uncommon injuries which invariably poses challenges in the management. Perilunate fracture dislocations are the combination of ligamentous and osseous injury that involve the "greater arc" of the perilunate associated instability. Despite their severity, these injuries often go unrecognized in the emergency department leading to delayed diagnosis and treatment. A Prospective study was done from June 2008 to December 2013 in 15 cases of complex wrist injuries which included of greater arch injuries, perilunate fracture dislocation and one dorsal dislocation of Scaphoid. 10 cases of perilunate fracture dislocation underwent open reduction and internal fixation with Herbert screw and k-wire, 4 cases of greater arch injury underwent closed reduction and kwire fixation and one case of neglected dorsal dislocation underwent proximal row carpectomy. One patient had Sudecks osteodystrophy 1 had Scaphoid nonunion and 6 had median nerve compression. Overall outcome according to Mayo wrist score was 53 % excellent, 33 % good and 14 % fair. Greater arch injuries are difficult to treat because injuries to many ligaments are involved and failure to recognize early leads to persistent pain, disability and early onset of arthritis. Prompt recognition requires CT scan and MRI. Management requires reduction and multiple K-Wiring according to merits of the case. PMID:25414554

  14. The ARCHES Project

    NASA Astrophysics Data System (ADS)

    Motch, C.; Arches Consortium

    2015-09-01

    The Astronomical Resource Cross-matching for High Energy Studies (ARCHES) project is a FP7-Space funded programme started in 2013 and involving the Observatoire Astronomique de Strasbourg including the CDS (France), the Leibniz- Institut für Astrophysik Potsdam (Germany), the University of Leicester (UK), the Universidad de Cantabria (IFCA, Spain) and the Instituto Nacional de Tecnica Aeroespacial (Spain). ARCHES will provide the international astronomical community with well-characterised multi-wavelength data in the form of spectral energy distributions (SEDs) for large samples of objects extracted from the 3XMM X-ray catalogue of serendipitous sources. The project develops new tools implementing fully probabilistic simultaneous cross-correlation of several catalogues and a multi-wavelength finder for clusters of galaxies. SEDs are based on an enhanced version of the 3XMM catalogue and on a careful selection of the most relevant multi-wavelength archival catalogues. In order to ensure the largest audience, SEDs will be distributed to the international community through CDS services and through the Virtual Observatory. These enhanced resources are tested in the framework of several science cases. More information may be found at http://www.arches-fp7.eu/

  15. Double arch mirror study

    NASA Technical Reports Server (NTRS)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    The development of a method of mounting light weight glass mirrors for astronomical telescopes compatible with the goals of the Shuttle Infrared Telescope Facility (SIRTF) was investigated. A 20 in. diameter double arch lightweight mirror previously fabricated was modified to use a new mount configuration. This mount concept was developed and fabricated. The mounting concept of the double mounting mirror is outlined. The modifications made to the mirror, fabrication of the mirror mount, and room temperature testing of the mirror and mount and the extension of the mirror and mount concept to a full size (40 in. diameter) primary mirror for SIRTF are discussed.

  16. 35. ALTERNATE DESIGN USING THROUGH ARCH SPANS, WITH ARCH REPEATED ...

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

    35. ALTERNATE DESIGN USING THROUGH ARCH SPANS, WITH ARCH REPEATED BETWEEN TOWER LEGS, AND ASHLAR MASONRY WALLS AND PYLONS Pen-and-ink drawing by project architect Alfred Eichler, 1934. - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

  17. The ARCHES project

    NASA Astrophysics Data System (ADS)

    Motch, C.; Arches Consortium

    2014-07-01

    ARCHES (Astronomical Resource Cross-matching for High Energy Studies) is a FP7-Space funded project started in 2013 and involving the Observatoire Astronomique de Strasbourg including the CDS (France), the Leibniz-Institut fuer Astrophysik Potsdam (Germany), the University of Leicester (UK), the Universidad de Cantabria (IFCA, Spain) and the Instituto Nacional de Técnica Aeroespacial (Madrid, Spain). ARCHES aims at providing the international astronomical community with well-characterised multi-wavelength data in the form of spectral energy distributions (SEDs) for large sets of objects extracted from the 3XMM catalogue. The project develops new tools implementing fully probabilistic simultaneous cross-correlation of several catalogues. SEDs are based on an enhanced version of the 3XMM catalogue and on a careful selection of the most relevant multi-wavelength archival catalogues. In order to ensure the largest audience, SEDs will be distributed to the international community through CDS services and through the Virtual Observatory. These enhanced resources are currently tested in the framework of several science cases. An integrated cluster finder is developed at Potsdam, AGN science is studied at Leicester and IFCA while populations of Galactic X-ray sources are investigated at Strasbourg and Madrid.

  18. [A treatment chart adapted to the arch form].

    PubMed

    Bocquet-Moreau, E; Danguy, Ch; Bertrand, J; Danguy, M

    2005-12-01

    Arch wires used in orthodontic treatment must conform to the shape of the dental arches so that in their final positions teeth will be set in a pathway of neuromuscular equilibrium. However, sometimes distortions of the alveoli deform the shape of the arch. In such cases the treatment charts constructed on the actual alveolo-dental relationship will not reflect desired objectives. We believe that the transverse muco-gingival dimension Andrews called the Wala line responds better to therapeutic requirements. Moreover, molar attachments, key elements of a full-banded appliance, are in harmony with it. So the type of chart that the authors propose for use with the Straight Wire technique, one based on the Wala line, will help orthodontists place teeth at the conclusion of orthodontic treatment in the best possible relationships to patients' specific anatomic configurations. PMID:16471375

  19. Equivalent Imperfections In Arched Structures

    NASA Astrophysics Data System (ADS)

    Dallemule, Marian

    2015-09-01

    There are currently three design methods to verify the in-plane buckling of an arched structure: substitute member method, the method of equivalent imperfection with recommendations for arched bridges, and the equivalent unique global and local initial imperfection method (EUGLI), which uses the critical elastic buckling mode as an imperfection. The latter method is included in the EN 1993-1-1 cl. 5.3.2 (11) since 2002; however, to this day it is neither utilized in the design practice nor is it incorporated in ordinary structural analysis software. The main purpose of this article is to show the application of the proposed methods in a step-by-step manner to the numerical example considered and to compare these design methods for various arched structures. Verification of the in-plane buckling of an arch is explained in detail.

  20. Pseudoaneurysm of the aortic arch

    PubMed Central

    Lu, Yuan-Qiang; Yao, Feng; Shang, An-Dong; Pan, Jian

    2016-01-01

    Abstract Background: Pseudoaneurysm of the aortic arch is uncommonly associated with cancer, and is extremely rare in pulmonary cancer. Here, we report an unusual and successfully treated case of aortic arch pseudoaneurysm in a male patient with lung squamous cell carcinoma. Methods: A 64-year-old male patient was admitted to the Emergency Department, presenting with massive hemoptysis (>500 mL blood during the 12 hours prior to treatment). The diagnosis of aortic arch pseudoaneurysm was confirmed after inspection of computed tomographic angiography and three-dimensional reconstruction. We processed the immediate endovascular stent-grafting for this patient. Results: This patient recovered with no filling or enlargement of the pseudoaneurysm, no episodes of hemoptysis, and no neurological complications during the 4-week follow-up period. Conclusion: Herein, we compare our case with other cancer-related pseudoaneurysms in the medical literature and summarize the clinical features and treatment of this unusual case. PMID:27495079

  1. Ambient resonance of rock arches

    NASA Astrophysics Data System (ADS)

    Starr, Alison Margaret

    Resonant frequencies of structural elements are related to fundamental material properties of mass and stiffness, and monitoring over time can thus serve as an indirect indictor of internal mechanical change. Until now, however, this methodology has not been applied to natural rock structures such as arches and towers. We evaluated the resonance characteristics of four rock arches in southeastern Utah, combining in-situ ambient vibration measurements with numerical modal analysis. At each location, we measured the spectral and polarization attributes of ambient vibrations using up to two broadband seismometers. Ambient vibration spectra measured on the arches showed clear peaks at distinct frequencies (typically between 1-10 Hz), which we interpret as resonant frequencies, as opposed to the relatively flat spectra recorded on nearby bedrock. Polarization analysis helped us identify the orientations of vibration and explore resonant mode shapes. We then verified the measured resonant frequencies through 3D finite-element numerical modal analysis, and in most cases we were able to match the fundamental along with several higher-order modes. Repeat occupation and short-term continuous ambient vibration monitoring were aimed at assessing daily and seasonal changes in resonant frequencies, which in turn may provide evidence of internal mechanical change; Mesa Arch in Canyonlands National Park served as the main focus for our repeat measurements. Results revealed that minor, reversible changes in resonant frequencies can be created by thermal effects, i.e., changes in bulk material stiffness as the arch expands and contracts on daily and seasonal time scales. No irreversible change in the resonant frequency of Mesa Arch was detected over the period of this study. Our research provides the first step towards monitoring the long-term structural health of natural rock arches as they change through time or in the wake of a damaging event. We have shown that the resonance

  2. Comparison of Commercially Available Arch Wires with Normal Dental Arch in a Group of Iranian Population

    PubMed Central

    Hedayati, Zohreh; Fakhri, Farnaz; Moshkel Gosha, Vahid

    2015-01-01

    Statement of the Problem The stability of orthodontic treatment depends on preserving the patient’s pretreatment arch form and arch size during and after treatment. Purpose This investigation was aimed to study the size and shape of Iranian mandibular dental arch and evaluate the correlation of their average dental arch with commercially available preformed rectangular nickel-titanium arch wires. Materials and Method In this study, 148 subjects were selected among students of Shiraz University of Medical Sciences. The inclusion criteria were having Angle class I in molar and canine relationships, and normal growth pattern. Intercanine and intermolar widths were measured after scanning their mandibular dental casts. Three main arch form templates; square, ovoid and tapered (Orthoform TM; 3M, Unitek, CA, USA) and 12 commercially available preformed mandibular nickel-titanium arch wires were scanned. Intercanine and intermolar widths of arch wires were compared with dental arch widths of the study samples. Arch width, arch form and the most appropriate arch wire were determined for each cast. Student’s t-test was used to compare arch widths and arch depths of male and female subjects. Coefficient of variance was used to determine the variability of indices in the study samples. Results Most preformed arch wires were wider than the average width of the normal Iranian dental arch. The most frequent arch form in Iranian population was tapered. Inter molar width was the only statistically significant variable between males and females. Conclusion Variation in available preformed arch wires does not entirely cover the range of diversity of the normal dental arch of our population. Narrow arch wires with a tapered shape are better consistent with the Iranian lower arch. PMID:26046106

  3. Persistent Fifth Aortic Arch with Coarctation

    PubMed Central

    Kim, Sue Hyun; Choi, Eun-Suk; Cho, Sungkyu; Kim, Woong-Han

    2016-01-01

    Persistent fifth aortic arch (PFAA) is a rare congenital anomaly of the aortic arch frequently associated with other cardiovascular anomalies, such as tetralogy of Fallot and aortic arch coarctation or interruption. We report the case of a neonate with PFAA with coarctation who successfully underwent surgical repair. PMID:26889445

  4. The Algebra of the Arches

    ERIC Educational Resources Information Center

    Buerman, Margaret

    2007-01-01

    Finding real-world examples for middle school algebra classes can be difficult but not impossible. As we strive to accomplish teaching our students how to solve and graph equations, we neglect to teach the big ideas of algebra. One of those big ideas is functions. This article gives three examples of functions that are found in Arches National…

  5. The ARCHES Integrated Cluster Finder

    NASA Astrophysics Data System (ADS)

    Mints, A.; Schwope, A.

    2014-07-01

    We are developing a tool to search for galaxy clusters associated with X-ray sources from the 3XMM catalog within the ARCHES project (Astronomical Resource cross-matching for High-Energy Studies). We make use of the new cross-matching tool developed for ARCHES to select galaxies in different catalogs around X-ray positions and then try to find clusters by searching for overdensities in the multi-color space. Colors are related to redshifts using spectroscopic data for passively evolving galaxies from the BOSS and VIPERS catalogs. So far we are making use of SDSS, UKIDSS, WISE, and CFHTLS photometric catalogs, but the method can easily be expanded to other data as well (e.g. Pan-STARRS and DES). We present test results of our tool performed on reference samples from the XMM/SDSS cluster survey (Takey et al 2012) and the NORAS/REFLEX surveys.

  6. Cervical aortic arch and a new type of double aortic arch. Report of a case.

    PubMed Central

    Cornali, M; Reginato, E; Azzolina, G

    1976-01-01

    A case of cervical aortic arch is reported. To the best of our knowledge, it is the first to be associated with a serious intracardiac anomaly. In addition, it is part of a new type of double aortic arch, caused by failure of reabsorption of both dorsal aortic roots and persistence of the fourth right and second (or third) left branchial arches. PMID:971387

  7. 22. VIEW OF STEEL ARCH, SHOWING ABUTMENT INTERIOR, DETAIL OF ...

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

    22. VIEW OF STEEL ARCH, SHOWING ABUTMENT INTERIOR, DETAIL OF ARCH BEARINGS WITH HINGED SEATS AND LATERAL BRACING OF ARCHES, LOOKING NORTH - Notre Dame Bridge, Spanning Merrimack River on Bridge Street, Manchester, Hillsborough County, NH

  8. Maxillary and mandibular anterior crown width/height ratio and its relation to various arch perimeters, arch length, and arch width groups

    PubMed Central

    Shahid, Fazal; Alam, Mohammad Khursheed; Khamis, Mohd Fadhli

    2015-01-01

    Objective: To investigate the maxillary and mandibular anterior crown width/height ratio and its relation to various arch perimeters, arch length, and arch width (intercanine, interpremolar, and intermolar) groups. Materials and Methods: The calculated sample size was 128 subjects. The crown width/height, arch length, arch perimeter, and arch width of the maxilla and mandible were obtained via digital calliper (Mitutoyo, Japan). A total of 4325 variables were measured. The sex differences in the crown width and height were evaluated. Analysis of variance was applied to evaluate the differences between arch length, arch perimeter, and arch width groups. Results: Males had significantly larger mean values for crown width and height than females (P ≤ 0.05) for maxillary and mandibular arches, both. There were no significant differences observed for the crown width/height ratio in various arch length, arch perimeter, and arch width (intercanine, interpremolar, and intermolar) groups (P ≤ 0.05) in maxilla and mandible, both. Conclusions: Our results indicate sexual disparities in the crown width and height. Crown width and height has no significant relation to various arch length, arch perimeter, and arch width groups of maxilla and mandible. Thus, it may be helpful for orthodontic and prosthodontic case investigations and comprehensive management. PMID:26929686

  9. Techniques for aortic arch endovascular repair.

    PubMed

    kHONGKU, Kiattisak; Dias, Nuno; Sonesson, Bjorn; Resch, Timothy

    2016-06-01

    This article reviews endovascular strategies for aortic arch repair. Open repair remains the gold standard particularly for good risk patients. Endovascular treatment potentially offers a less invasive repair. Principles, technical considerations, devices and outcomes of each technique are discussed and summarized. Hybrid repair combines less invasive revascularization options, instead of arch replacement while extending stent-graft into the arch. Outcomes vary with regard to extent of repair and aortic arch pathologies treated. Results of arch chimney and other parallel graft techniques perhaps make it a less preferable choice for elective cases. However, they are very appealing options for urgent or bailout situations. Fenestrated stent-grafting is subjected to many technical challenges in aortic arch due to difficulties in stent-graft orientation and fenestration positioning. In situ fenestration techniques emerge to avoid these problems, but durability of stent-grafts after fenestration and ischemic consequences of temporary carotid arteries coverage raises some concern total arch repair using this technique. Arch branched graft is a new technology. Early outcomes did not meet the expectation; however the results have been improving after its learning curve period. Refining stent-graft technologies and implantation techniques positively impact outcomes of endovascular approaches. PMID:26940011

  10. El problema de estabilidad de los sistemas Hamiltonianos multidimensionales

    NASA Astrophysics Data System (ADS)

    Cincotta, P. M.

    Se revisarán los aspectos básicos del problema de estabilidad de sistemans Hamiltonianos N-dimensionales, haciendo especial énfasis en los posibles mecanismos que dan lugar a la aparición de ``caos": overlap de resonancias, difusión de Arnol'd y otros procesos difusivos alternativos. Se mencionarán los aspectos aún no resueltos sobre la estabilidad de los sistemas con N > 2. Finalmente, se discutirá cuáles de estos mecanismos podrían tener alguna relevancia en la dinámica de sistemas estelares y planetarios.

  11. Partition Equilibrium

    NASA Astrophysics Data System (ADS)

    Feldman, Michal; Tennenholtz, Moshe

    We introduce partition equilibrium and study its existence in resource selection games (RSG). In partition equilibrium the agents are partitioned into coalitions, and only deviations by the prescribed coalitions are considered. This is in difference to the classical concept of strong equilibrium according to which any subset of the agents may deviate. In resource selection games, each agent selects a resource from a set of resources, and its payoff is an increasing (or non-decreasing) function of the number of agents selecting its resource. While it has been shown that strong equilibrium exists in resource selection games, these games do not possess super-strong equilibrium, in which a fruitful deviation benefits at least one deviator without hurting any other deviator, even in the case of two identical resources with increasing cost functions. Similarly, strong equilibrium does not exist for that restricted two identical resources setting when the game is played repeatedly. We prove that for any given partition there exists a super-strong equilibrium for resource selection games of identical resources with increasing cost functions; we also show similar existence results for a variety of other classes of resource selection games. For the case of repeated games we identify partitions that guarantee the existence of strong equilibrium. Together, our work introduces a natural concept, which turns out to lead to positive and applicable results in one of the basic domains studied in the literature.

  12. Helical equilibrium

    SciTech Connect

    Yoshikawa, S.

    1981-08-01

    A straight, helical plasma equilibrium equation is solved numerically for a plasma with a helical magnetic axis. As is expected, by a suitable choice of the plasma boundary, the vacuum configuration is made line ..integral.. dl/B stable. As the plasma pressure increases, the line ..integral.. dl/B criterion will improve (again as expected). There is apparently no limit on the plasma ..beta.. from the equilibrium consideration. Thus helical-axis stellarator ..beta.. will presumably be limited by MHD stability ..beta.., and not by equilibrium ..beta...

  13. Glowing Solar Material Arches Up and Out

    NASA Video Gallery

    An elongated, streaming arch of solar material rose up at the sun’s edge before breaking apart in this animation of imagery captured by NASA’s Solar Dynamics Observatory on April 28, 2016. While so...

  14. Integrated exploration locates Cincinnati arch dolomite breccias

    SciTech Connect

    Tedesco, S.A. )

    1994-11-28

    Dolomite breccias or chimneys are prolific reservoirs found along the Cincinnati arch and adjacent basins from Tennessee to Ontario. An integrated approach using seismic and surface geochemistry, augmented by subsurface geology and magnetics, has led to a dramatic increase in the number of these fields being discovered in the past 10 years. Historically the reservoirs have been found by random drilling. The paper describes the geology of the arch, breccia characteristics, and case histories of discoveries using this integrated approach.

  15. Mandibular arch perimeter changes with lip bumper treatment.

    PubMed

    Osborn, W S; Nanda, R S; Currier, G F

    1991-06-01

    The effects of lip bumper treatment on the mandibular arch were observed in 32 patients with late transitional and early permanent dentitions. Dental cast measurements were made for arch perimeter, arch length, and arch width. Cephalometric radiographs were used to determine labial tipping of the incisors and distal movement of the molars. Arch circumference increased in all patients, ranging from 0.7 mm to 8.8 mm, with an average of 4.1 mm. The mean increase in arch length was 1.2 mm and was largely attributed to anterior tipping of the mandibular incisors. Change in arch length was the most predictive variable for the increase in arch circumference. Passive changes in arch width were recorded, with a mean increase of 2.0 mm in the intercanine distance and 2.5 mm in the first premolar distance. Arch width increments contributed to the increase in arch circumference, but the increases in arch width were not found to be predictive of the change in arch circumference. Changes in either arch circumference or arch length were not related to the duration of treatment, age and sex of the patient, or the eruption status of the permanent second molars. PMID:2038972

  16. Designing light responsive bistable arches for rapid, remotely triggered actuation

    NASA Astrophysics Data System (ADS)

    Smith, Matthew L.; Shankar, M. Ravi; Backman, Ryan; Tondiglia, Vincent P.; Lee, Kyung Min; McConney, Michael E.; Wang, David H.; Tan, Loon-Seng; White, Timothy J.

    2014-03-01

    Light responsive azobenzene functionalized polymer networks enjoy several advantages as actuator candidates including the ability to be remotely triggered and the capacity for highly tunable control via light intensity, polarization, wavelength and material alignments. One signi cant challenge hindering these materials from being employed in applications is their often relatively slow actuation rates and low power densities, especially in the absence of photo-thermal e ects. One well known strategy employed in nature for increasing actuation rate and power output is the storage and quick release of elastic energy (e.g., the Venus ytrap). Using nature as inspiration we have conducted a series of experiments and developed an equilibrium mechanics model for investigating remotely triggered snap-through of bistable light responsive arches made from glassy azobenzene functionalized polymers. After brie y discussing experimental observations we consider in detail a geometrically exact, planar rod model of photomechanical snap-through. Theoretical energy release characteristics and unique strain eld pro les provide insight toward design strategies for improved actuator performance. The bistable light responsive arches presented here are potentially a powerful option for remotely triggered, rapid motion from apparently passive structures in applications such as binary optical switches and positioners, surfaces with morphing topologies, and impulse locomotion in micro or millimeter scale robotics.

  17. Hydatid cyst involving the aortic arch.

    PubMed

    Apaydin, Anil Z; Oguz, Emrah; Zoghi, Mehdi

    2007-03-01

    We report a very rare case of primary mediastinal hydatid cyst which invaded the ascending aorta and the aortic arch which initially presented as a cranial mass. Aortic wall is a very unusual site for the hydatid cysts. To the best of our knowledge, this is the first reported case of hydatid cyst located within the aortic arch lumen. Patient underwent ascending aortic and hemiarch replacement under hypothermic circulatory arrest and removal of the cyst. Patient had an uneventful recovery and has been on follow-up. Although the literature data are very limited, we believe that the aortic procedure of choice should be graft interpositon rather than patch repair. PMID:17215134

  18. 18. SOUTHERNMOST ARCH TOP AND BUTTRESS, AT TURNING POINT WHERE ...

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

    18. SOUTHERNMOST ARCH TOP AND BUTTRESS, AT TURNING POINT WHERE THE EARTHEN EMBANKMENT MEETS THE CONCRETE ARCH DAM. VIEW TO SOUTHWEST. - Rock Creek Dam, East end of Rock Creek Road, Auburn, Placer County, CA

  19. 20. WEST CONFEDERATE AVENUE BRIDGE SPANNING CODON'S RUN, ARCH DETAIL ...

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

    20. WEST CONFEDERATE AVENUE BRIDGE SPANNING CODON'S RUN, ARCH DETAIL SHOWING BRICK ARCH FOR MAIN SPAN AND STONE VOUSSOIRS. VIEW W. - Gettysburg National Military Park Tour Roads, Gettysburg, Adams County, PA

  20. 8. GENERAL ELEVATION OF BRIDGE AFTER CONCRETE FOR ARCHES HAS ...

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

    8. GENERAL ELEVATION OF BRIDGE AFTER CONCRETE FOR ARCHES HAS BEEN POURED BUT BEFORE FALSEWORK HAS BEEN REMOVED. TAKEN JAN 7, 1928. - Marsh Rainbow Arch Bridge, West Eighth Street North, Newton, Jasper County, IA

  1. 2. LONGITUDINAL VIEW OF THE CONCRETE ARCH (ONEWAY BRIDGE), LOOKING ...

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

    2. LONGITUDINAL VIEW OF THE CONCRETE ARCH (ONE-WAY BRIDGE), LOOKING NORTHEAST. - Washington Water Power Company Post Falls Power Plant, Concrete Arch Bridge, West of intersection of Spokane & Fourth Streets, Post Falls, Kootenai County, ID

  2. View of Highway 140 west of Arch Rock. Note stone ...

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

    View of Highway 140 west of Arch Rock. Note stone wall at right and formed concrete wall at center. Looking north-northwest - All Year Highway, Between Arch Rock & Yosemite Valley, El Portal, Mariposa County, CA

  3. 3. View locking east of 591 foot steel arch of ...

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

    3. View locking east of 591 foot steel arch of bridge. Arch consists of Pratt trusses divided into twenty-four, 24 foot, 7 inch panels. It was fabricated by the King Iron Bridge Company of Cleveland whose circular plaque can be seen where the arch meets the roadway. The steel arch was erected by the Berro construction Co. of Chicago. - Detroit Superior High Level Bridge, Cleveland, Cuyahoga County, OH

  4. The Tidal Radius of the Arches Cluster

    NASA Astrophysics Data System (ADS)

    Hosek, Matthew; Lu, Jessica R.; Anderson, Jay; Ghez, Andrea; Morris, Mark; Clarkson, William

    2015-08-01

    At a projected distance of just ˜26 pc from the center of the Milky Way, the Arches cluster allows us to examine the structure of a young massive cluster in the strong tidal environment of the Galactic center (GC). We use the HST WFC3IR camera to conduct an astrometric and photometric study of the outer region of the Arches cluster (R > 6.25”) in order to measure its radial profile. Using proper motions we separate cluster members from field stars down to F153M = 20 mag (˜2.5 M_sun) over a 120” x 120” field of view, covering an area 144 times larger than previous proper motion studies. This is a significant improvement over photometrically-determined cluster membership, which is complicated by the high degree of differential reddening across the field. Using cluster membership probabilities, a derived extinction map, and extensive completeness simulations, we construct the radial profile of the Arches cluster to a radius of ˜80” (˜3.1 pc assuming a distance of 8 kpc). Evidence of mass segregation out to this radius is observed, and no significant tidal tail structure is apparent. We find that the projected radial extent of the Arches cluster is significantly larger than its expected tidal radius. This result suggests either that the cluster is not as close to the GC as previously thought or that it is inflated beyond its nominal tidal radius.

  5. Increased plantar force and impulse in American football players with high arch compared to normal arch

    PubMed Central

    Carson, Daniel W.; Myer, Gregory D.; Hewett, Timothy E.; Heidt, Robert S.; Ford, Kevin R.

    2014-01-01

    Background Risk of overuse injury among athletes is high due in part to repeated loading of the lower extremities. Compared to individuals with normal arch (NA) structure, those with high (HA) or low arch (LA) may be at increased risk of specific overuse injuries, including stress fractures. A high medial longitudinal arch may result in decreased shock absorbing properties due to increased rigidity in foot mechanics. While the effect of arch structure on dynamic function has been examined in straight line walking and running, the relationship between the two during multi-directional movements remains unstudied. Objective The purpose of this study was to determine if differences in plantar loading in football players occur during both walking and pivoting movements. Method Plantar loading was examined in 9 regions of the foot for 26 participants (16 NA, 10 HA). Results High arch athletes demonstrated increased maximum force in the lateral rear foot and medial forefoot, and force time integral in the medial forefoot while walking. HA athletes also demonstrated increased maximum force in the medial rear foot and medial and central forefoot during rapid pivoting. Conclusions The current findings demonstrate that loading patterns differ between football players with high and normal arch structure, which could possibly influence injury risk in this population. PMID:23141809

  6. Aortic arch repair today: open repair is best for most arch lesions.

    PubMed

    Coselli, J S; Green, S Y

    2015-08-01

    The transverse aortic arch is challenging to repair by either evolving open or emerging endovascular approaches. Contemporary experience in aortic arch repair can be difficult to assess because clinical practice varies substantially among centers with regard to temperature targets for hypothermic circulatory arrest, temperature monitoring sites, circulating perfusate temperatures, cerebral perfusion monitoring techniques, perfusion catheter flow rates, cannulation sites, pH management, and protective pharmacologic agents. Repair of the aortic arch has changed substantially over the last decade; these changes appear to have substantially reduced patient risk. In general, contemporary outcomes of open aortic arch repair are good to excellent. When acute aortic dissection is absent, many centers report early mortality rates below 5%; when acute aortic dissection is present, these rates are doubled or tripled. Not unexpectedly, mortality rates for total transverse aortic arch repair with elephant trunk or frozen elephant trunk approaches are greater than those for hemiarch repair (7-17% vs. 3-4%). In contemporary reports of mixed hemiarch and total arch repairs for aortic aneurysm, several authors report early mortality rates and stroke rates below 5%. Surprisingly, mortality rates for reoperation are not unlike those for primary repair and range from 8% to 9%; however, the risk of stroke appears somewhat greater and ranges from 5% to 6%. PMID:25752255

  7. Equilibrium Shaping

    NASA Astrophysics Data System (ADS)

    Izzo, Dario; Petazzi, Lorenzo

    2006-08-01

    We present a satellite path planning technique able to make identical spacecraft aquire a given configuration. The technique exploits a behaviour-based approach to achieve an autonomous and distributed control over the relative geometry making use of limited sensorial information. A desired velocity is defined for each satellite as a sum of different contributions coming from generic high level behaviours: forcing the final desired configuration the behaviours are further defined by an inverse dynamic calculation dubbed Equilibrium Shaping. We show how considering only three different kind of behaviours it is possible to acquire a number of interesting formations and we set down the theoretical framework to find the entire set. We find that allowing a limited amount of communication the technique may be used also to form complex lattice structures. Several control feedbacks able to track the desired velocities are introduced and discussed. Our results suggest that sliding mode control is particularly appropriate in connection with the developed technique.

  8. Evaluation of the fit of preformed nickel titanium arch wires on normal occlusion dental arches

    PubMed Central

    Al-Barakati, Rakhn G.; Alqahtani, Nasser D.; AlMadi, Abdulaziz; Albarakati, Sahar F.; ALKofide, Eman A.

    2015-01-01

    Aim To determine the fits of preformed nickel titanium (NiTi) archwires on dental arches with normal occlusion. Methods Forty sets of upper and lower plaster models were obtained from men and women with Class I occlusions. Preformed 0.016″ × 0.022″ NiTi archwires from Rocky Mountain Orthodontics (RMO), 3 M Unitek, Ormco, and Dentaurum were evaluated in terms of their fits on dental arches from male, female, and combined cases. Data were analyzed by using fourth- and sixth-order polynomial equations, analysis of variance (ANOVA), and the Duncan post hoc test. Results In the upper arches, the best fit and least error were obtained with RMO Ovoid and Ormco Orthos Large archwires for male cases, but with 3 M Orthoform LA archwires for female and combined cases. In the lower arches, the best fit and least error were obtained with Ormco Orthos Large for male cases, with 3 M Orthoform LA and RMO Normal for female cases, and with 3 M Orthoform LA, RMO Normal, Ormco Orthos Large, and Ormco Orthos Small for combined cases. When both dental arches were matched, Ormco Orthos Large was the best wire for male cases. 3 M Orthoform LA was the best wire for female and combined cases. Conclusions Using an archwire form with the best fit to the dental arch should produce minimal changes in the dental arch form when NiTi wires are used and require less customization when stainless-steel wires are used. PMID:26792965

  9. Saccular Aneurysms of the Transverse Aortic Arch

    PubMed Central

    Preventza, Ourania; Coselli, Joseph S.

    2015-01-01

    Saccular aneurysms of the aortic arch, whether single or multiple, are uncommon. The choice of repair technique is influenced by patients' comorbidities and age. Repairing saccular aneurysms with traditional open techniques can be technically demanding; therefore, endovascular technology and a variety of hybrid approaches have been developed to facilitate such repairs and, potentially, to improve clinical outcomes, especially in high-risk patients. There have been no large, randomized studies to compare the outcomes of these different treatment options in patients with single or multiple saccular aneurysms of the arch. In this review, we outline the etiology and common locations of these aneurysms, the different open, completely endovascular, and hybrid techniques used to treat them, and the treatment selection process. PMID:26798759

  10. [Single coronary artery and right aortic arch].

    PubMed

    Martínez-Quintana, Efrén; Rodríguez-González, Fayna

    2015-01-01

    Coronary anomalies are mostly asymptomatic and diagnosed incidentally during coronary angiography or echocardiography. However, they must be taken into account in the differential diagnosis of angina, dyspnea, syncope, acute myocardial infarction or sudden death in young patients. The case is presented of two rare anomalies, single coronary artery originating from right sinus of Valsalva and right aortic arch, in a 65 year-old patient with atherosclerotic coronary artery disease treated percutaneously. PMID:25304052

  11. Crater-Like Ulceration of Aortic Arch.

    PubMed

    Simon, Caterina; Calabrese, Alice; Canu, Gianluca; Merlo, Maurizio; Galletti, Lorenzo

    2014-12-01

    We report the case of a 78-year-old female who presented to our hospital with signs of hemorrhagic shock and breathlessness. A transthoracic echocardiography demonstrated pericardial effusion. Computed tomography of the chest showed a penetrating atherosclerotic ulcer of the aortic arch with an intramural hematoma of the ascending and descending aorta. Endovascular repair with stent-grafting was urgently performed and a pericardial window placement was done to reduce mediastinal bleeding. PMID:26798748

  12. Mycotic aneurysm of the aortic arch.

    PubMed

    Aliaga, L; Cobo, F; Miranda, C; Lara, J

    2000-01-01

    A 61-year-old diabetic woman presented with a mycotic aneurysm of the aortic arch, also involving the left subclavian and vertebral arteries, caused by Staphylococcus aureus. Two months before, she had suffered from staphylococcal septic arthritis in her left knee. The patient was treated with antibiotics and an emergency operation was performed involving aneurysm excision and in situ synthetic graft replacement. She died on the fourth postoperative day from hemorrhagic shock. PMID:10961533

  13. Hybrid treatment of aortic arch disease

    PubMed Central

    Metzger, Patrick Bastos; Rossi, Fabio Henrique; Moreira, Samuel Martins; Issa, Mario; Izukawa, Nilo Mitsuru; Dinkhuysen, Jarbas J.; Spina Neto, Domingos; Kambara, Antônio Massamitsu

    2014-01-01

    Introduction The management of thoracic aortic disease involving the ascending aorta, aortic arch and descending thoracic aorta are technically challenging and is an area in constant development and innovation. Objective To analyze early and midterm results of hybrid treatment of arch aortic disease. Methods Retrospective study of procedures performed from January 2010 to December 2012. The end points were the technical success, therapeutic success, morbidity and mortality, neurologic outcomes, the rate of endoleaks and reinterventions. Results A total of 95 patients treated for thoracic aortic diseases in this period, 18 underwent hybrid treatment and entered in this study. The average ages were 62.3 years. The male was present in 66.7%. The technical and therapeutic success was 94.5% e 83.3%. The perioperative mortality rate of 11.1%. There is any death during one-year follow- up. The reoperation rates were 16.6% due 2 cases of endoleak Ia and one case of endoleak II. There is any occlusion of anatomic or extra anatomic bypass during follow up. Conclusion In our study, the hybrid treatment of aortic arch disease proved to be a feasible alternative of conventional surgery. The therapeutic success rates and re- interventions obtained demonstrate the necessity of thorough clinical follow-up of these patients in a long time. PMID:25714205

  14. Jurassic stratigraphy of the Wiggins Arch, Mississippi

    SciTech Connect

    Rhodes, J.A.; Maxwell, G.B. )

    1993-09-01

    Mobil and Shell jointly explored the Wiggins arch area in southern Mississippi from 1985 to 1991. The effort concentrated on the Jurassic Norphlet and Smackover formations. Two wells were drilled into Paleozoic crystalline rocks and one well into the Pine Hill formation. Two of these wells were located on the southern side of the Wiggins arch and provide significant data for interpreting Jurassic stratigraphy. The Mobil No. 1 U.S.A. well encountered a complete Jurassic section, but with some significantly different facies than those encountered by wells to the north. A granite wash section is the equivalent to the Frisco City formation previously only found 100 mi to the north-northeast. All 300 ft of Smackover is crystalline dolomite. The Norphlet section is entirely granite wash. The Pine Hill anhydrite is unusually thick and interpreted to be equivalent to the Louann Salt. Correlations to other wells on the Wiggins arch, particularly the Conoco No. 1 Higgins, indicate that the Jurassic can be divided into three transgressive events separated by the Norphlet/Pine Hill and Frisco City/Buckner regressive events.

  15. Oblique slip in Laramide foreland arches

    SciTech Connect

    Erslev, E.A.; Selvig, B.; Molzer, P. . Dept. of Earth Resources)

    1993-03-01

    Don Wise was one of the first structural geologists to recognize the complex, four-dimensional (space and time) nature of basement-involved faulting in the Rocky Mountain foreland. His focus on both small scale kinematic indicators and regional tectonic hypotheses has provided a launching point for many Rocky Mountain geologists. The implications of the anastomosing patterns of Laramide foreland arches on models of regional stress and strain have provoked considerable debate. Hypotheses range from those invoking multiple stages of lateral compression from different directions to single-stage models necessitating a component of strike-slip motion in east-west and north-south arches. These hypotheses were tested using slickenline analysis of minor faulting in structures with different orientations. In Wyoming, structures paralleling the dominant northwest structural trend have slickenlines in the NE-SW vertical plane, consistent with shortening and compression in this direction. The east-west Owl Creek and Casper Mountain structures also have NE-SW trending slickenlines, indicating slip oblique to these arches. In Colorado, minor faults in the north-south margin of the northeastern Front Range also indicate oblique slip, with shortening in the NE-SW quadrant. The actual trend of the slickenlines is more easterly, however, suggesting a change of slip trajectory with latitude, not time, possibly in response to identation by the Colorado Plateau.

  16. Variations among the primary maxillary dental arch forms using a polynominal equation model.

    PubMed

    Tsai, Hung-Huey

    2003-01-01

    This study identifies arch symmetry and describes arch form variations in normal primary maxillary dental casts. Sixty-two percent of casts had asymmetrical arches, and 38% had symmetrical arches. Six types of arch form were identified according to the ratio of arch width to length. There were more long types than short types. The rounded and short types tended to have a more-symmetrical arch than did the long type. PMID:12739689

  17. The Foot's Arch and the Energetics of Human Locomotion.

    PubMed

    Stearne, Sarah M; McDonald, Kirsty A; Alderson, Jacqueline A; North, Ian; Oxnard, Charles E; Rubenson, Jonas

    2016-01-01

    The energy-sparing spring theory of the foot's arch has become central to interpretations of the foot's mechanical function and evolution. Using a novel insole technique that restricted compression of the foot's longitudinal arch, this study provides the first direct evidence that arch compression/recoil during locomotion contributes to lowering energy cost. Restricting arch compression near maximally (~80%) during moderate-speed (2.7 ms(-1)) level running increased metabolic cost by + 6.0% (p < 0.001, d = 0.67; unaffected by foot strike technique). A simple model shows that the metabolic energy saved by the arch is largely explained by the passive-elastic work it supplies that would otherwise be done by active muscle. Both experimental and model data confirm that it is the end-range of arch compression that dictates the energy-saving role of the arch. Restricting arch compression had no effect on the cost of walking or incline running (3°), commensurate with the smaller role of passive-elastic mechanics in these gaits. These findings substantiate the elastic energy-saving role of the longitudinal arch during running, and suggest that arch supports used in some footwear and orthotics may increase the cost of running. PMID:26783259

  18. The Impact of Subject Age, Gender, and Arch Length on Attitudes of Syrian Dentists towards Shortened Dental Arches

    PubMed Central

    Nassani, Mohammad Zakaria; Al-Nahhal, Tammam Ibrahim; Kujan, Omar; Tarakji, Bassel; Kay, Elizabeth Jane

    2015-01-01

    Objective. This study aimed to investigate the impact of subject age, gender, and arch length on dentists' attitudes towards unrestored shortened dental arches. Materials and Methods. 93 Syrian dentists were interviewed and presented with 24 scenarios for male and female subjects of different ages and shortened dental arches of varying length. Participants were asked to indicate on a standardized visual analogue scale how they would value the health of the mouth if the posterior space was left unrestored. Results. A value of 0.0 represented the worst possible health state for a mouth and 1.0 represented the best. The highest mean value (0.73) was assigned to a shortened dental arch with missing second molar teeth in the mouth of a 70-year-old subject. A 35-year-old female subject with an extremely shortened dental arch (all molar and premolar teeth are missing) attracted the lowest mean value (0.26). The statistical analysis indicated a significant decrease in the value placed on unrestored shortened dental arches as the number of remaining teeth decreased (p < 0.008). While subject gender had almost no impact on dentists' attitudes towards shortened dental arches, the scenarios for the older shortened dental arch subjects attracted significantly higher values compared to the scenarios for the younger subjects (p < 0.017). Conclusion. Subject age and arch length affect dentists' attitudes towards shortened dental arches, but subject gender does not. PMID:26265916

  19. Estabilidad de los modelos de Heggie y Ramamani

    NASA Astrophysics Data System (ADS)

    Muzzio, J. C.; Vergne, M. M.; Wachlin, F. C.; Carpintero, D. D.

    Los modelos de Heggie y Ramamani de satélites galácticos en órbitas circulares se basan en una teoría aproximada, por lo que es importante verificar su estabilidad mediante simulaciones numéricas. En esta forma, hemos logrado mostrar que son estables sobre intervalos de tiempo mucho mayores que los que lograron los propios autores de los modelos. Por otra parte, dado que hemos mostrado que el caos es significativo en estos modelos, son un sistema ideal para investigar si, pese a ello, se mantienen estacionarios. Nuestras simulaciones numéricas muestran que, pese al caos, la estacionariedad se mantiene sobre intervalos de centenares de tiempos de cruce del sistema, mucho mayores que los tiempos de Liapunov característicos de sus movimientos caóticos.

  20. Detail of arched windows on north elevation; camera facing southwest. ...

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

    Detail of arched windows on north elevation; camera facing southwest. - Mare Island Naval Shipyard, Smithery, California Avenue, west side at California Avenue & Eighth Street, Vallejo, Solano County, CA

  1. ARCH TYPE MAGAZINE # 2131. INTERIOR LOOKING TOWARD ENTRY. ...

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

    ARCH TYPE MAGAZINE # 2131. INTERIOR LOOKING TOWARD ENTRY. - Naval Magazine Lualualei, Headquarters Branch, Magazine Type, Various roads in northern & eastern portions of installation, Pearl City, Honolulu County, HI

  2. 16. DETAIL OF SMALL ARCHES AT SOUTH END, FROM WEST. ...

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

    16. DETAIL OF SMALL ARCHES AT SOUTH END, FROM WEST. - Philadelphia & Reading Railroad, Wissahickon Creek Viaduct, Spanning Wissahickon Creek, north of Ridge Avenue Bridge, Philadelphia, Philadelphia County, PA

  3. 15. DETAIL OF SMALL ARCHES AT SOUTH END, FROM WEST. ...

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

    15. DETAIL OF SMALL ARCHES AT SOUTH END, FROM WEST. - Philadelphia & Reading Railroad, Wissahickon Creek Viaduct, Spanning Wissahickon Creek, north of Ridge Avenue Bridge, Philadelphia, Philadelphia County, PA

  4. 4. North elevation, arch CD. View south Ashton Viaduct, ...

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

    4. North elevation, arch C-D. View south - Ashton Viaduct, State Route 116 (Washington Highway) spanning Blackstone River, Blackstone Canal, & Providence & Worcester Railroad, Ashton, Providence County, RI

  5. Mathematical model of a moment-less arch

    PubMed Central

    2016-01-01

    This paper presents a mathematical model for predicting the geometrical shapes of rigid, two-pin, moment-less arches of constant cross section. The advancement of this work lies in the inclusion of arch self-weight and the ability to produce moment-less arch forms for any span/rise ratio, and any ratio of uniformly distributed load per unit span, w, to uniformly distributed arch weight per unit arch length, q. The model is used to derive the shapes of two classical ‘moment-less’ arch forms: parabolic and catenary, prior to demonstrating a general case, not restricted by the unrealistic load assumptions (absence of q, in the case of a parabolic form, or no w, in the case of a catenary arch). Using the same value of span/rise ratio, and w/q>1, the behaviour of the moment-less and parabolic arches under permanent loading, (w+q), is analysed. Results show the former to be developing much lower stresses than its parabolic rival, even when there are relatively small differences in the two geometries; for a medium span/rise ratio of 4 and w/q=2, differences in the parabolic and moment-less arch geometries would, in practical terms, be viewed as insignificant, but the stresses in them are different. PMID:27436970

  6. Normal azygos arch: retrotracheal visualization on frontal chest tomograms.

    PubMed

    Austin, J H; Thorsen, M K

    1981-12-01

    Anteroposterior, linear tomograms of 78 adult subjects in the supine position revealed visualization of pleural reflections off the retrotracheal part of the normal azygos arch in 38 (49%). The course of the arch varied by about 3 cm. Five distinct patterns were found, mainly depending on the course of the inferior margin of the arch. The inferior margin varied from relatively superior retrotracheal positions to intermediate positions appearing to intersect the carina, to relatively inferior and right-sided positions posterior to the proximal right main bronchus. Recognition of these normal variations of the azygos arch should serve to differentiate them from abnormalities in this region. PMID:6976093

  7. 66. CORBELS, BLIND ARCHES & SHIELDS, COMMONS EAST WALL, LOOKING ...

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

    66. CORBELS, BLIND ARCHES & SHIELDS, COMMONS EAST WALL, LOOKING EAST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  8. 2. DETAIL VIEW OF MIDDLE ARCH SPAN, LOOKING NORTHWEST. ...

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

    2. DETAIL VIEW OF MIDDLE ARCH SPAN, LOOKING NORTHWEST. - Cumberland & Pennsylvania Railroad, Wills Creek Bridge, Spanning Wills Creek 587 feet West of Eckhart Junction, Cumberland, Allegany County, MD

  9. The Geologic Story of Arches National Park

    USGS Publications Warehouse

    Lohman, Stanley William

    1975-01-01

    According to former Superintendent Bates Wilson (1956), Prof. Lawrence M. Gould, of the University of Michigan, was the first to recognize the geologic and scenic values of the Arches area in eastern Utah and to urge its creation as a national monument. Mrs. Faun McConkie Tanner told me that Professor Gould, who had done a thesis problem in the nearby La Sal Mountains, was first taken through the area by Marv Turnbow, third owner of Wolfe cabin. (See p. 12.) When Professor Gould went into ecstasy over the beautiful scenery, Turnbow replied, 'I didn't know there was anything unusual about it.'

  10. Standardizing Foot-Type Classification Using Arch Index Values

    PubMed Central

    Weil, Rich; de Boer, Emily

    2012-01-01

    ABSTRACT Purpose: The lack of a reliable classification standard for foot type makes drawing conclusions from existing research and clinical decisions difficult, since different foot types may move and respond to treatment differently. The purpose of this study was to determine interrater agreement for foot-type classification based on photo-box-derived arch index values. Method: For this correlational study with two raters, a sample of 11 healthy volunteers with normal to obese body mass indices was recruited from both a community weight-loss programme and a programme in physical therapy. Arch index was calculated using AutoCAD software from footprint photographs obtained via mirrored photo-box. Classification as high-arched, normal, or low-arched foot type was based on arch index values. Reliability of the arch index was determined with intra-class correlations; agreement on foot-type classification was determined using quadratic weighted kappa (κw). Results: Average arch index was 0.215 for one tester and 0.219 for the second tester, with an overall range of 0.017 to 0.370. Both testers classified 6 feet as low-arched, 9 feet as normal, and 7 feet as high-arched. Interrater reliability for the arch index was ICC=0.90; interrater agreement for foot-type classification was κw=0.923. Conclusions: Classification of foot type based on arch index values derived from plantar footprint photographs obtained via mirrored photo-box showed excellent reliability in people with varying BMI. Foot-type classification may help clinicians and researchers subdivide sample populations to better differentiate mobility, gait, or treatment effects among foot types. PMID:23729964

  11. Clinical Evaluation of Efficacy of CIA and CNA Intrusion Arches

    PubMed Central

    Vora, Sambhav; Pandey, Vinisha

    2015-01-01

    Background and Objectives Excessive overbite is one of the most common problems that confront the orthodontist. Deep bite can be due to infraocclusion of posterior teeth, supraocclusion of anterior teeth or a combination of the two. Correction of same can be carried out by extrusion of molars, intrusion of incisors or by a combination of both respectively. Various intrusion arches are recommended for correcting deep bite by true intrusion of anterior teeth, Utility arches, Segmental arch, Connecticut Intrusion Arch (CIA) and Connecticut New Arch (CNA). The purpose of this study was to evaluate clinical efficacy of CIA and CNA intrusion arches. Materials and Methods Tracings recorded from pre and post-treatment lateral cephalograms of 25 patients treated by CIA (Group I) and another 25 patients treated by CNA (Group II) intrusion arches in deep bite cases after four months of treatment were analysed and findings were recorded. Statistical Analysis Paired t-test was used to compare pre and post-treatment changes within Groups I and II and unpaired t-test was used to compare treatment changes between Group I and Group II. A P-value of < 0.05 was set for statistical significance. Results Findings of this study demonstrate that an average of 1mm of intrusion takes place with CIA intrusion arch and 1.3mm with CNA intrusion arch in a period of 4 months. Both intrusion arches do not affect the position of molar in vertical or anteroposterior plane. Interpretation & Conclusion Both CIA and CNA intrusion arches are effective in bringing about intrusion of lower incisors. PMID:26501008

  12. Blood flow characteristics in the aortic arch

    NASA Astrophysics Data System (ADS)

    Prahl Wittberg, Lisa; van Wyk, Stevin; Mihaiescu, Mihai; Fuchs, Laszlo; Gutmark, Ephraim; Backeljauw, Philippe; Gutmark-Little, Iris

    2012-11-01

    The purpose with this study is to investigate the flow characteristics of blood in the aortic arch. Cardiovascular diseases are associated with specific locations in the arterial tree. Considering atherogenesis, it is claimed that the Wall Shear Stress (WSS) along with its temporal and spatial gradients play an important role in the development of the disease. The WSS is determined by the local flow characteristics, that in turn depends on the geometry as well as the rheological properties of blood. In this numerical work, the time dependent fluid flow during the entire cardiac cycle is fully resolved. The Quemada model is applied to account for the non-Newtonian properties of blood, an empirical model valid for different Red Blood Cell loading. Data obtained through Cardiac Magnetic Resonance Imaging have been used in order to reconstruct geometries of the the aortic arch. Here, three different geometries are studied out of which two display malformations that can be found in patients having the genetic disorder Turner's syndrome. The simulations show a highly complex flow with regions of secondary flow that is enhanced for the diseased aortas. The financial support from the Swedish Research Council (VR) and the Sweden-America Foundation is gratefully acknowledged.

  13. 3. PORTAL VIEW OF THE CONCRETE ARCH (ONEWAY BRIDGE) THAT ...

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

    3. PORTAL VIEW OF THE CONCRETE ARCH (ONE-WAY BRIDGE) THAT PROVIDES ACCESS TO THE MIDDLE CHANNEL DAM AND POWER PLANT, LOOKING WEST. - Washington Water Power Company Post Falls Power Plant, Concrete Arch Bridge, West of intersection of Spokane & Fourth Streets, Post Falls, Kootenai County, ID

  14. 1. CONTEXTUAL VIEW, LOOKING DOWNSTREAM (NORTHERLY) OF THE CONCRETE ARCH ...

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

    1. CONTEXTUAL VIEW, LOOKING DOWNSTREAM (NORTHERLY) OF THE CONCRETE ARCH ('ONE-WAY BRIDGE') THAT PROVIDES PRIVATE (WWP) ACCESS TO THE MIDDLE CHANNEL OF THE POST FALLS POWER PLANT. - Washington Water Power Company Post Falls Power Plant, Concrete Arch Bridge, West of intersection of Spokane & Fourth Streets, Post Falls, Kootenai County, ID

  15. 4. PORTAL VIEW OF THE CONCRETE ARCH (ONEWAY BRIDGE) THAT ...

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

    4. PORTAL VIEW OF THE CONCRETE ARCH (ONE-WAY BRIDGE) THAT EXITS THE MIDDLE CHANNEL ISLAND AND POST FALLS POWER PLANT, LOOKING EAST. - Washington Water Power Company Post Falls Power Plant, Concrete Arch Bridge, West of intersection of Spokane & Fourth Streets, Post Falls, Kootenai County, ID

  16. VIEW TO THE SOUTHEAST. SPANDREL ARCHES OF THE KELLER BRIDGE ...

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

    VIEW TO THE SOUTHEAST. SPANDREL ARCHES OF THE KELLER BRIDGE ARE SEEN ON THE LEFT; THE SUPERSTRUCTURE OF THE TENNESSEE RIVER RISES ABOVE THE KELLER AND OBSCURES ITS ARCHES. - Keller Memorial Bridge, Spanning Tennessee River at U.S. Highway 31, Decatur, Morgan County, AL

  17. Aortic arch vessel anomalies associated with persistent trigeminal artery.

    PubMed

    Lotfi, Mehrzad; Nabavizadeh, Seyed Ali; Foroughi, Amin Abolhasani

    2012-01-01

    Developmental anomalies of the aortic arch vessels and persistent trigeminal artery that is the most common of the four anomalous carotid-basilar anastomoses are repeatedly reported in the literature as separate entities. Herein we report a previously undescribed variant including the coexistence of persistent trigeminal artery, truncus bicaroticus and direct origin of left vertebral artery from aortic arch. PMID:22542381

  18. Elemental composition of background soils from Arches National Park, Utah

    SciTech Connect

    Gladney, E.S.; Ferenbaugh, R.W.; Belnap, J.

    1993-05-01

    Background elemental data on soil composition at Arches National Park are reported. The enrichment factor analysis of the soil data from Arches National Park provides some interpretation of the current elemental status of soils at the park. These data provide a basis for determining changes in elemental enrichment status in the future.

  19. 4. ATTLEBORO VIADUCT SHOWING MILL STREET ARCH AT LEFT, ATTLEBORO ...

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

    4. ATTLEBORO VIADUCT SHOWING MILL STREET ARCH AT LEFT, ATTLEBORO STATION AT LEFT CENTER AND SOUTH MAIN STREET ARCH AT RIGHT. ATTLEBORO, BRISTOL CO., MA. Sec. 4116, MP 197.16. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

  20. 15. Arched, concrete bridge along elevated rightofway of Shaker Rapid ...

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

    15. Arched, concrete bridge along elevated right-of-way of Shaker Rapid Transit through the east side of city of Cleveland, labelled: 'View Toward West Along Northerly Side Arches at E. 90th St. and Westerly.' 1914. - Shaker Heights Rapid Transit Line, Cleveland, Cuyahoga County, OH

  1. 6. Southwest facing view of the Romanesque Arches. Horizontal line ...

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

    6. Southwest facing view of the Romanesque Arches. Horizontal line above the arches marks the 1923 raising of the dam. Flashboards cap the dam. - Glens Falls Dam, 100' to 450' West of U.S. Route 9 Bridge Spanning Hudson River, Glens Falls, Warren County, NY

  2. 20. VIEW OF STEEL ARCH, SHOWING UNDERSIDE OF BRIDGE DECK ...

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

    20. VIEW OF STEEL ARCH, SHOWING UNDERSIDE OF BRIDGE DECK AT EAST END, TYPICAL FLOOR BEAM DETAILS AND IRVING DECKING, X-BRACING AND PENETRATION OF ARCH LOWER CHORD THROUGH DECK, LOOKING NORTHWEST. GAS LINE IS CARRIED ON FLOOR BEAM OUTRIGGERS. NEW BRIDGE IS AT LEFT - Notre Dame Bridge, Spanning Merrimack River on Bridge Street, Manchester, Hillsborough County, NH

  3. 10. COPY OF OBLIQUE PHOTOGRAPH SHOWING ARCH HANGAR AT RIGHT, ...

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

    10. COPY OF OBLIQUE PHOTOGRAPH SHOWING ARCH HANGAR AT RIGHT, BUILDING 8200 (OBSERVATION TOWER) AT LEFT, AND B-52 AIRCRAFT PARKED ALONG APRON IN BACKGROUND, DATED OCTOBER 1967, PHOTOGRAPH FROM BASE MASTER PLAN LOCATED AT AIR FORCE BASE CONVERSION AGENCY, LORING AIR FORCE BASE, MAINE. - Loring Air Force Base, Arch Hangar, East of Arizona Road near southern end of runway, Limestone, Aroostook County, ME

  4. 12. AN IMAGE OF THE ARCH ENTRADOS LOOKING SOUTH FROM ...

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

    12. AN IMAGE OF THE ARCH ENTRADOS LOOKING SOUTH FROM THE NORTH SIDE OF U.S. 40. THIS DETAIL CLEARLY SHOWS THE FOUR LONGITUDINAL ARCH CASTINGS AND THE GHOSTS OF THE BOARDS USED AS FORMS. - Vandalia Railroad Bridge, Spanning U.S. Route 40, Indianapolis, Marion County, IN

  5. ELEVATION VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, ...

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

    ELEVATION VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, VIEW OF NORTH ARCH FOLLOWING REMOVAL OF TRAVELING FORMWORK, VIEW TO EAST. - Rex T. Barber Veterans Memorial Bridge, Spanning Crooked River Gorge, Dalles-California Highway (US 97), Terrebonne, Deschutes County, OR

  6. PERSPECTIVE VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, ...

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

    PERSPECTIVE VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, VIEW OF SOUTH TRAVELING FORMWORK AND NORTH ARCH PRIOR TO CLOSURE POUR. - Rex T. Barber Veterans Memorial Bridge, Spanning Crooked River Gorge, Dalles-California Highway (US 97), Terrebonne, Deschutes County, OR

  7. Minimally Invasive Techniques for Total Aortic Arch Reconstruction

    PubMed Central

    Faulds, Jason; Sandhu, Harleen K.; Estrera, Anthony L.; Safi, Hazim J.

    2016-01-01

    The cumulative experience with endovascular aortic repair in the descending thoracic and infrarenal aorta has led to increased interest in endovascular aortic arch reconstruction. Open total arch replacement is a robust operation that can be performed with excellent results. However, it requires cardiopulmonary bypass and circulatory arrest and, therefore, may not be tolerated by all patients. Minimally invasive techniques have been considered as an alternative and include hybrid arch debranching, parallel stent graft deployment in the chimney and snorkel configurations, and complete endovascular branched reconstruction with multi-branched devices. This review discusses the evolving use of endovascular techniques in the management of aortic arch pathology and considers their relevance in an era of safe and durable open aortic arch reconstruction. PMID:27127562

  8. Minimally Invasive Techniques for Total Aortic Arch Reconstruction.

    PubMed

    Faulds, Jason; Sandhu, Harleen K; Estrera, Anthony L; Safi, Hazim J

    2016-01-01

    The cumulative experience with endovascular aortic repair in the descending thoracic and infrarenal aorta has led to increased interest in endovascular aortic arch reconstruction. Open total arch replacement is a robust operation that can be performed with excellent results. However, it requires cardiopulmonary bypass and circulatory arrest and, therefore, may not be tolerated by all patients. Minimally invasive techniques have been considered as an alternative and include hybrid arch debranching, parallel stent graft deployment in the chimney and snorkel configurations, and complete endovascular branched reconstruction with multi-branched devices. This review discusses the evolving use of endovascular techniques in the management of aortic arch pathology and considers their relevance in an era of safe and durable open aortic arch reconstruction. PMID:27127562

  9. Origin of arches in the northwestern Gulf of Mexico basin

    SciTech Connect

    Laubach, S.E.; Jackson, M.L.W. )

    1990-07-01

    The San Marcos and Sabine arches are prominent north- to northwest-trending basement uplifts in the northwestern Gulf of Mexico basin that may be late Mesozoic to Cenozoic foreland or intraplate folds rather than domes over plutons or buoyant basement blocks. These arches are subparallel to and contemporaneous with orogenic episodes in the northwest-trending fold-thrust belt of Mexico. Arch movement was also contemporaneous with rapid convergence between the North American and Pacific plates. Arch development in the gulf as a result of tectonic compression is plausible in view of increasing recognition of wide zones of foreland and intraplate deformation in continents. Current tectonic models of the development of the gulf inaccurately predict gradual, decelerating subsidence when these arches were most active.

  10. Ambient resonance of Mesa Arch, Canyonlands National Park, Utah

    NASA Astrophysics Data System (ADS)

    Starr, Alison M.; Moore, Jeffrey R.; Thorne, Michael S.

    2015-08-01

    We analyzed the resonance characteristics of a prominent natural arch in Canyonlands National Park, Mesa Arch, as measured from ambient seismic data. Evaluating spectral and polarization attributes, we distinguished the first four resonant frequencies of the arch, 2.9, 6.0, 6.9, and 8.5 Hz, as well as basic properties of the associated mode shapes. We then affirmed experimental data using 3-D numerical modal analysis, providing estimates of material properties and clarifying vibrational mode shapes. Monitoring resonant frequencies over time, we searched for shifts associated with changing environmental conditions and long-term progressive damage. We measured ~3% direct daily variation in resonant frequency associated with changing rock temperature, thermal stress, and stiffening of the rock matrix. Independent tilt data showed similar diurnal cycles associated with thermoelastic stresses and deformation of the arch. We observed no permanent resonant frequency shifts related to irreversible damage of Mesa Arch during our study period.

  11. Critical Transitions in Early Embryonic Aortic Arch Patterning and Hemodynamics

    PubMed Central

    Kowalski, William J.; Dur, Onur; Wang, Yajuan; Patrick, Michael J.; Tinney, Joseph P.; Keller, Bradley B.; Pekkan, Kerem

    2013-01-01

    Transformation from the bilaterally symmetric embryonic aortic arches to the mature great vessels is a complex morphogenetic process, requiring both vasculogenic and angiogenic mechanisms. Early aortic arch development occurs simultaneously with rapid changes in pulsatile blood flow, ventricular function, and downstream impedance in both invertebrate and vertebrate species. These dynamic biomechanical environmental landscapes provide critical epigenetic cues for vascular growth and remodeling. In our previous work, we examined hemodynamic loading and aortic arch growth in the chick embryo at Hamburger-Hamilton stages 18 and 24. We provided the first quantitative correlation between wall shear stress (WSS) and aortic arch diameter in the developing embryo, and observed that these two stages contained different aortic arch patterns with no inter-embryo variation. In the present study, we investigate these biomechanical events in the intermediate stage 21 to determine insights into this critical transition. We performed fluorescent dye microinjections to identify aortic arch patterns and measured diameters using both injection recordings and high-resolution optical coherence tomography. Flow and WSS were quantified with 3D computational fluid dynamics (CFD). Dye injections revealed that the transition in aortic arch pattern is not a uniform process and multiple configurations were documented at stage 21. CFD analysis showed that WSS is substantially elevated compared to both the previous (stage 18) and subsequent (stage 24) developmental time-points. These results demonstrate that acute increases in WSS are followed by a period of vascular remodeling to restore normative hemodynamic loading. Fluctuations in blood flow are one possible mechanism that impacts the timing of events such as aortic arch regression and generation, leading to the variable configurations at stage 21. Aortic arch variations noted during normal rapid vascular remodeling at stage 21 identify a

  12. Determining shapes and dimensions of dental arches for the use of straight-wire arches in lingual technique

    PubMed Central

    Kairalla, Silvana Allegrini; Scuzzo, Giuseppe; Triviño, Tarcila; Velasco, Leandro; Lombardo, Luca; Paranhos, Luiz Renato

    2014-01-01

    INTRODUCTION: This study aims to determine the shape and dimension of dental arches from a lingual perspective, and determine shape and size of a straight archwire used for lingual Orthodontics. METHODS: The study sample comprised 70 Caucasian Brazilian individuals with normal occlusion and at least four of Andrew's six keys. Maxillary and mandibular dental casts were digitized (3D) and the images were analyzed by Delcam Power SHAPET 2010 software. Landmarks on the lingual surface of teeth were selected and 14 measurements were calculated to determine the shape and size of dental arches. RESULTS: Shapiro-Wilk test determined small arch shape by means of 25th percentile (P25%) - an average percentile for the medium arch; and a large one determined by means of 75th percentile (P75%). T-test revealed differences between males and females in the size of 12 dental arches. CONCLUSION: The straight-wire arch shape used in the lingual straight wire technique is a parabolic-shaped arch, slightly flattened on its anterior portion. Due to similarity among dental arch sizes shown by males and females, a more simplified diagram chart was designed. PMID:25715725

  13. First Branchial Arch Fistula: A Rarity and a Surgical Challenge

    PubMed Central

    Rajkumar, J.S.; Anirudh, J.R.; Akbar, S.; Joshi, Niraj

    2016-01-01

    Although 2nd Branchial arch fistulae (from incomplete closure of Cervical sinus of His) are well known, 1st arch fistulae are much rarer (<10%) and are usually not tackled comprehensively. We present a case of a rare first branchial arch fistula of the type II Arnot classification, which presented with two external openings of more than 20 years duration. Patient had a successful resection of all the concerned fistulous tract. Review of literature and the surgical challenges of the procedure are presented herewith.

  14. 19. SECOND FLOOR, CITY COMMISSION CHAMBERS, DETAIL OF ARCH WITH ...

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

    19. SECOND FLOOR, CITY COMMISSION CHAMBERS, DETAIL OF ARCH WITH MURAL ON RIGHT OF BENCH, SHOWING PIONEERS AND ATLANTIC CITY SEAL - City Hall, Atlantic & Tennessee Avenues, Atlantic City, Atlantic County, NJ

  15. Detail of arched window and eaves molding on west elevation; ...

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

    Detail of arched window and eaves molding on west elevation; camera facing east. - Mare Island Naval Shipyard, Old Administrative Offices, Eighth Street, north side between Railroad Avenue & Walnut Avenue, Vallejo, Solano County, CA

  16. Interior detail of main entry lobby showing arched hallways and ...

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

    Interior detail of main entry lobby showing arched hallways and staircase; camera facing north. - Mare Island Naval Shipyard, Old Administrative Offices, Eighth Street, north side between Railroad Avenue & Walnut Avenue, Vallejo, Solano County, CA

  17. NASA’s SDO Captures Cascading Magnetic Arches

    NASA Video Gallery

    A dark solar filament above the sun's surface became unstable and erupted on Dec. 16-17, 2015, generating a cascade of magnetic arches. A small eruption to the upper right of the filament was likel...

  18. 28. Brick apartment buildings with arched window openings, string courses, ...

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

    28. Brick apartment buildings with arched window openings, string courses, a brick cornice, and an interrupted brick frieze. - Butte Historic District, Bounded by Copper, Arizona, Mercury & Continental Streets, Butte, Silver Bow County, MT

  19. 39. ARCHED HERRINGBONE BRICK PATTERN DETAIL ON FRONT OF 1931 ...

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

    39. ARCHED HERRINGBONE BRICK PATTERN DETAIL ON FRONT OF 1931 SECTION, PROJECTING SIDE BAY, TAKEN FROM THE NORTH. - James Russell Lowell Elementary School, 4501 Crittenden Drive, Louisville, Jefferson County, KY

  20. 38. RECESSED ARCH DETAIL WITH STONE SCONCE ON FRONT OF ...

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

    38. RECESSED ARCH DETAIL WITH STONE SCONCE ON FRONT OF 1931 SECTION, PROJECTING SIDE BAY, TAKEN FROM THE NORTH. - James Russell Lowell Elementary School, 4501 Crittenden Drive, Louisville, Jefferson County, KY

  1. 14. BRIDGE ABUTMENT AND ARCH TRUSS MOUNTING PLATE SHOWING EYEBAR ...

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

    14. BRIDGE ABUTMENT AND ARCH TRUSS MOUNTING PLATE SHOWING EYE-BAR CONNECTION AND EYE-BAR PIN LOCATION - Spruce Street Bridge, East Spruce Street, 500 Block, spanning Power Canal, Sault Ste. Marie, Chippewa County, MI

  2. SPRINGING OF THE ARCH, SOUTH END OF BRIDGE, STATEN ISLAND ...

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

    SPRINGING OF THE ARCH, SOUTH END OF BRIDGE, STATEN ISLAND SIDE (CONTACT PRINT MADE FROM 5 1/4" X 4 1/2" NEGATIVE) - Bayonne Bridge, Spanning Kill Van Kull between Bayonne & Staten Island, Bayonne, Hudson County, NJ

  3. 5. BUILDING 0503, INTERIOR WOODEN ARCHES. Looking south from entrance. ...

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

    5. BUILDING 0503, INTERIOR WOODEN ARCHES. Looking south from entrance. - Edwards Air Force Base, South Base Sled Track, Earth Covered Bunker Types, North of Sled Track, Lancaster, Los Angeles County, CA

  4. 10. DETAIL OF CONNECTION AT INTERSECTION OF BURR ARCH AND ...

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

    10. DETAIL OF CONNECTION AT INTERSECTION OF BURR ARCH AND VERTICAL MEMBER OF PRATT TRUSS - Kuhn's Fording Bridge, Spanning Conewago Creek on Township Road 552 (Hamilton & Reading townships), East Berlin, Adams County, PA

  5. 5. ATTLEBORO VIADUCT: PARK STREET ARCHES. ATTLEBORO,, BRISTOL CO., MA. ...

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

    5. ATTLEBORO VIADUCT: PARK STREET ARCHES. ATTLEBORO,, BRISTOL CO., MA. Sec. 4116, MP 197.38. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

  6. 11. Detail of laminated arch beams, radiators, pews and portion ...

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

    11. Detail of laminated arch beams, radiators, pews and portion of the office to the left of the sanctuary, facing north - Mountain Home Air Force Base, Base Chapel, 350 Willow Street, Cantonment Area, Mountain Home, Elmore County, ID

  7. 16. OBLIQUE VIEW OF UNDERSTRUCTURE, SHOWING NORTH PIER, ARCH RIBS, ...

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

    16. OBLIQUE VIEW OF UNDERSTRUCTURE, SHOWING NORTH PIER, ARCH RIBS, COLUMNS, AND SWAY BRACING, LOOKING SOUTH - Chili Bar Bridge, Spanning South Fork of American River at State Highway 193, Placerville, El Dorado County, CA

  8. 18. VIEW OF UNDERSTRUCTURE, SHOWING ARCH RIBS, COLUMNS, AND SWAY ...

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

    18. VIEW OF UNDERSTRUCTURE, SHOWING ARCH RIBS, COLUMNS, AND SWAY BRACING, LOOKING SOUTHWEST FROM NORTH ABUTMENT - Chili Bar Bridge, Spanning South Fork of American River at State Highway 193, Placerville, El Dorado County, CA

  9. 36. DETAIL, ALTERNATE DESIGN USING THROUGH ARCH SPANS Pencil drawing ...

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

    36. DETAIL, ALTERNATE DESIGN USING THROUGH ARCH SPANS Pencil drawing by project architect Alfred Eichler, ca. 1934. - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

  10. Cellar: Detail of paired relieving arch and remains of herringbone ...

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

    Cellar: Detail of paired relieving arch and remains of herringbone brick pattern from earlier cooking fireplace at back, southeast wall looking southeast - Kingston-Upon-Hill, Kitts Hummock Road, Dover, Kent County, DE

  11. 6. BASEMENT OF FRONT HOUSE, NORTH WALL BRICK ARCHES SUPPORT ...

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

    6. BASEMENT OF FRONT HOUSE, NORTH WALL BRICK ARCHES SUPPORT ALLEY AT FIRST FLOOR LEVEL. Photo by Theodore F. Dillon, August 1960 - Captain James Abercrombie House, 268-270 South Second Street, Philadelphia, Philadelphia County, PA

  12. 1. Elkmont vehicle bridge at Elkmont Campground, galvanized corrugated arch. ...

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

    1. Elkmont vehicle bridge at Elkmont Campground, galvanized corrugated arch. - Great Smoky Mountains National Park Roads & Bridges, Elkmont Vehicle Bridge, Spanning Little River at Elkmont Campground, Gatlinburg, Sevier County, TN

  13. 3. DETAIL OF STONEWORK ON ARCH, WATER TABLE AND DENTILS ...

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

    3. DETAIL OF STONEWORK ON ARCH, WATER TABLE AND DENTILS ON EAST ELEVATION LOOKING NORTHWEST. - Original Airport Entrance Overpass, Spanning original Airport Entrance Road at National Airport, Arlington, Arlington County, VA

  14. 9. Arch CD ring and spandrel column detail. View east ...

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

    9. Arch C-D ring and spandrel column detail. View east - Ashton Viaduct, State Route 116 (Washington Highway) spanning Blackstone River, Blackstone Canal, & Providence & Worcester Railroad, Ashton, Providence County, RI

  15. 8. Arch EF ring detail and east approach span. View ...

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

    8. Arch E-F ring detail and east approach span. View east - Ashton Viaduct, State Route 116 (Washington Highway) spanning Blackstone River, Blackstone Canal, & Providence & Worcester Railroad, Ashton, Providence County, RI

  16. Detail, center pier, showing rigidlyfixed arch ribs, starpattern balustrade, and ...

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

    Detail, center pier, showing rigidly-fixed arch ribs, star-pattern balustrade, and simple ornamentation including molded treatment of concrete, pyramidal pier cap, and stylized pilaster - Horner Street Bridge, Horner Street over Stonycreek River, Johnstown, Cambria County, PA

  17. 198. SPOUT RUN ARCH BRIDGE AND SPOUT RUN WESTBOUND BRIDGE ...

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

    198. SPOUT RUN ARCH BRIDGE AND SPOUT RUN WESTBOUND BRIDGE FROM POTOMAC RIVER LOOKING SOUTHWEST. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

  18. 24. Detail view north under bridge showing arched bascule girder, ...

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

    24. Detail view north under bridge showing arched bascule girder, deck girders and cross beams, and bracing of east bascule leaf. - Yellow Mill Bridge, Spanning Yellow Mill Channel at Stratford Avenue, Bridgeport, Fairfield County, CT

  19. 8. Detail view of pierced arch concrete rails and recessed ...

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

    8. Detail view of pierced arch concrete rails and recessed panel railing piers at the west pedestrian alcove, north side of the bridge. - Yellow Mill Bridge, Spanning Yellow Mill Channel at Stratford Avenue, Bridgeport, Fairfield County, CT

  20. PERSPECTIVE OF UNDERSIDE SHOWING ARCHED GIRDER AND SLAB CONSTRUCTION. NOTE ...

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

    PERSPECTIVE OF UNDERSIDE SHOWING ARCHED GIRDER AND SLAB CONSTRUCTION. NOTE TWISTED BAR STOCK REINFORCING CAN BE SEEN. - Keggereis Ford Bridge, Spanning West Branch Conococheague Creek at State Route 4006, Willow Hill, Franklin County, PA

  1. Arch development with trans-force lingual appliances.

    PubMed

    Clark, William J

    2005-01-01

    Trans-Force lingual appliances are designed to correct arch form in patients with contracted dental arches. Interceptive treatment with this new series of pre-activated lingual appliances offers new possibilities for arch development, in combination with fixed appliances. Palatal and lingual appliances insert in horizontal lingual sheaths in molar bands. No activation is required after the appliance is fitted, and this principle is extended to a series of appliances for sagittal and transverse arch development. Both sagittal and transverse appliances have additional components to achieve 3-way expansion where this is indicated. The invisible lingual appliances may be used in correction of all classes of malocclusion at any stage of development, from mixed dentition through permanent dentition, and this approach has wide indications in adult treatment. PMID:15794037

  2. 19. Detail, center hinge of south span arches, transverse floor ...

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

    19. Detail, center hinge of south span arches, transverse floor beams, deck cantilever, railings; view to northwest. - Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

  3. 4. SIDE VIEW OF BRIDGE, LOOKING SOUTHWEST, SHOWING ARCHES, CANTILEVERED ...

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

    4. SIDE VIEW OF BRIDGE, LOOKING SOUTHWEST, SHOWING ARCHES, CANTILEVERED WALKWAY, DECK BEAMS AND STREAMBED - Benson Street Concrete Bowstring Bridge, Spanning Mill Creek at Benson Street, Lockland, Hamilton County, OH

  4. 5. DETAIL VIEW OF JUNCTURE BETWEEN ARCH, AND ABUTMENT, SHOWING ...

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

    5. DETAIL VIEW OF JUNCTURE BETWEEN ARCH, AND ABUTMENT, SHOWING CANTILEVERED WALKWAY AND DECK BEAMS ON UNDERSIDE OF BRIDGE - Benson Street Concrete Bowstring Bridge, Spanning Mill Creek at Benson Street, Lockland, Hamilton County, OH

  5. Detail view highlighting the series of pointed arch windows along ...

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

    Detail view highlighting the series of pointed arch windows along the North Carrollton facade - Reformed Episcopal Church of the Rock of Ages, 1210 West Lanvale Street, Baltimore, Independent City, MD

  6. 1. South elevation, (lr) arches CD and DE. View north ...

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

    1. South elevation, (l-r) arches C-D and D-E. View north - Ashton Viaduct, State Route 116 (Washington Highway) spanning Blackstone River, Blackstone Canal, & Providence & Worcester Railroad, Ashton, Providence County, RI

  7. 7. (lr) Arches DE, CD, BC. View southwest Ashton ...

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

    7. (l-r) Arches D-E, C-D, B-C. View southwest - Ashton Viaduct, State Route 116 (Washington Highway) spanning Blackstone River, Blackstone Canal, & Providence & Worcester Railroad, Ashton, Providence County, RI

  8. 5. Railroad tracks, (lr) arches EF, DE, CD, BC. View ...

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

    5. Railroad tracks, (l-r) arches E-F, D-E, C-D, B-C. View southwest - Ashton Viaduct, State Route 116 (Washington Highway) spanning Blackstone River, Blackstone Canal, & Providence & Worcester Railroad, Ashton, Providence County, RI

  9. 6. (1r) Arches EF, DE. View southeast Ashton Viaduct, ...

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

    6. (1-r) Arches E-F, D-E. View southeast - Ashton Viaduct, State Route 116 (Washington Highway) spanning Blackstone River, Blackstone Canal, & Providence & Worcester Railroad, Ashton, Providence County, RI

  10. Arch construction at south end, looking east with Phoenix Iron ...

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

    Arch construction at south end, looking east with Phoenix Iron Company foundry in background. - Gay Street Bridge, Spanning French Creek at Gay Street (State Route 113), Phoenixville, Chester County, PA

  11. 1. CONTEXT SHOT LOOKING NORTHWEST, WITH BUILDING 8250 (ARCH HANGAR) ...

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

    1. CONTEXT SHOT LOOKING NORTHWEST, WITH BUILDING 8250 (ARCH HANGAR) IN BACKGROUND. - Loring Air Force Base, Double Cantilever Hangar, East of Arizona Road, west of southern portion of Taxiway J, Limestone, Aroostook County, ME

  12. 11. DETAIL OF WEST WEB, FROM STREAMBANK, SHOWING ARCH RIB, ...

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

    11. DETAIL OF WEST WEB, FROM STREAMBANK, SHOWING ARCH RIB, HANGERS, FLOOR BEAMS AND GUARDRAIL. VIEW TO NORTHEAST. - Rock Valley Bridge, Spanning North Timber Creek at Old U.S. Highway 30, Marshalltown, Marshall County, IA

  13. 12. DETAIL OF NORTH ABUTMENT, FROM BENEATH, SHOWING ARCH RIB ...

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

    12. DETAIL OF NORTH ABUTMENT, FROM BENEATH, SHOWING ARCH RIB AND FLOOR BEAM. VIEW TO NORTHEAST. - Rock Valley Bridge, Spanning North Timber Creek at Old U.S. Highway 30, Marshalltown, Marshall County, IA

  14. 10. DETAIL OF UNDERSIDE OF ARCH, SHOWING LOWER CHORDS, VERTICALS, ...

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

    10. DETAIL OF UNDERSIDE OF ARCH, SHOWING LOWER CHORDS, VERTICALS, LATERAL BRACES AND ABUTMENTS, VIEW TO SOUTHEAST. - Navajo Bridge, Spanning Colorado River at U.S. Highway 89 Alternate, Page, Coconino County, AZ

  15. Halfcellar underneath original house showing fireplace relieving arch at northwest ...

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

    Half-cellar underneath original house showing fireplace relieving arch at northwest end; enclosed "cheese" room to right - Scheetz Farm, House, 7161 Camp Hill Road, Fort Washington, Montgomery County, PA

  16. View of south entrance to #157 through south breezeway arches ...

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

    View of south entrance to #157 through south breezeway arches - National Home for Disabled Volunteer Soldiers, Pacific Branch, Mental Health Buildings, 11301 Wilshire Boulevard, West Los Angeles, Los Angeles County, CA

  17. Oblique view of arches and ironwork on south breezeway ...

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

    Oblique view of arches and ironwork on south breezeway - National Home for Disabled Volunteer Soldiers, Pacific Branch, Mental Health Buildings, 11301 Wilshire Boulevard, West Los Angeles, Los Angeles County, CA

  18. Detail perspective view of the Ten Mile Creek Bridge arch, ...

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

    Detail perspective view of the Ten Mile Creek Bridge arch, decorative cantilevered balustrade, and floor beams. - Ten Mile Creek Bridge, Spanning Ten Mile Creek on Oregon Coast Highway, Yachats, Lincoln County, OR

  19. Detail of arched window on north portion of south wing, ...

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

    Detail of arched window on north portion of south wing, showing stone foundation; camera facing north. - Mare Island Naval Shipyard, Smithery, California Avenue, west side at California Avenue & Eighth Street, Vallejo, Solano County, CA

  20. Detail of arched window by main entry on west elevation; ...

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

    Detail of arched window by main entry on west elevation; showing Stone Foundation; camera facing east. - Mare Island Naval Shipyard, Smithery, California Avenue, west side at California Avenue & Eighth Street, Vallejo, Solano County, CA

  1. 41. DETAIL OF DOUBLE WINDOW ELEMENT WITH ARCHED BRICK PATTERN ...

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

    41. DETAIL OF DOUBLE WINDOW ELEMENT WITH ARCHED BRICK PATTERN ON EAST SIDE OF 1931 SECTION, TAKEN FROM THE EAST. - James Russell Lowell Elementary School, 4501 Crittenden Drive, Louisville, Jefferson County, KY

  2. 18. SECOND FLOOR, CITY COMMISSION CHAMBERS, DETAIL OF ARCH WITH ...

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

    18. SECOND FLOOR, CITY COMMISSION CHAMBERS, DETAIL OF ARCH WITH MURAL ON LEFT OF BENCH, SHOWING SEAMEN,SCIENTIST,SPORTSMEN AND STATE SEAL - City Hall, Atlantic & Tennessee Avenues, Atlantic City, Atlantic County, NJ

  3. 30. Interior detail view of arched, steelframed stainedglass windows at ...

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

    30. Interior detail view of arched, steel-framed stained-glass windows at the landing of the south stairs in main lobby, view looking south - University of Oregon Museum of Art, 1470 Johnson Lane, Eugene, Lane County, OR

  4. 6. View southeast, west elevation, showing north arch span abutment ...

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

    6. View southeast, west elevation, showing north arch span abutment and central pier with nose on upstream side - Edna Dean Proctor Bridge, Spanning Contoacook River at State Route 114, Henniker, Merrimack County, NH

  5. Arch & Chord Joint Detail; Crossbracing Center Joint Detail; Chord, ...

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

    Arch & Chord Joint Detail; Crossbracing Center Joint Detail; Chord, Panel Post, Tie & Diagonal Brace Joint Detail; Chord, Panel Post, Tie & Crossbracing Joint Detail - Dunlapsville Covered Bridge, Spanning East Fork Whitewater River, Dunlapsville, Union County, IN

  6. 1. VIEW SOUTHWARD FROM SOUTHWEST CORNER FRONT AND ARCH STREETS ...

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

    1. VIEW SOUTHWARD FROM SOUTHWEST CORNER FRONT AND ARCH STREETS (2. N. Front Street starts at left) - North Front Street Area Study, 2-66 North Front Street (Commercial Buildings), Philadelphia, Philadelphia County, PA

  7. BLDG 2 INTERIOR SHOWING ARCHES IN HALL BY MAIN ENTRY ...

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

    BLDG 2 INTERIOR SHOWING ARCHES IN HALL BY MAIN ENTRY - Naval Magazine Lualualei, Headquarters Branch, Police Station, Kolekole Road & Constitution Street intersection, north side of main quad, Pearl City, Honolulu County, HI

  8. 22. STEEL ARCH SEGMENT AND VENT IN OFFICE, ROOM 2351, ...

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

    22. STEEL ARCH SEGMENT AND VENT IN OFFICE, ROOM 2351, SECOND FLOOR, NORTH SIDE. - Hughes Aircraft Company, Processing & Electronics Building, 6775 Centinela Avenue, Los Angeles, Los Angeles County, CA

  9. 69. INTERIOR VIEW OF ARCH OF BRIDGE OVER ORIGINAL HEADRACE ...

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

    69. INTERIOR VIEW OF ARCH OF BRIDGE OVER ORIGINAL HEADRACE (now in basement in front of north wing) (4' x 5' negative) - Fairmount Waterworks, East bank of Schuylkill River, Aquarium Drive, Philadelphia, Philadelphia County, PA

  10. 80. LITTLE ROCK DAM: DIMENSIONS, SECTION THROUGH ARCH RING, AMENDED ...

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

    80. LITTLE ROCK DAM: DIMENSIONS, SECTION THROUGH ARCH RING, AMENDED SHEET 5; SEPTEMBER, 1922. Palmdale Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  11. 8. VIEW NORTHWEST OF EAST ELEVATION SOUTH BARREL ARCH. NOTE ...

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

    8. VIEW NORTHWEST OF EAST ELEVATION SOUTH BARREL ARCH. NOTE STONE WORK, 1920 CONCRETE REPAIRS, AND STEEL BRACES ADDED BY THE NATIONAL PARK SERVICE CIRCA 1962. - Chesapeake & Ohio Canal, Conococheague Creek Aqueduct, Milepost 99.80, Williamsport, Washington County, MD

  12. 13. Detail of second story window arch, front side, left ...

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

    13. Detail of second story window arch, front side, left of north entrance - Oklahoma State University, Boys Dormitory, Northwest corner of Hester Street & Athletic Avenue, Stillwater, Payne County, OK

  13. Close view of the Constitution Avenue elevation to show arched ...

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

    Close view of the Constitution Avenue elevation to show arched gateways and pedimented pavilion ("Commerce and Communication" sculpted pediment) - Interstate Commerce Commission, Constitution Avenue between Twelfth and Fourteenth streets, Washington, District of Columbia, DC

  14. Detail view of keystone sculpted head in the arched passage ...

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

    Detail view of keystone sculpted head in the arched passage to the lobby vestibule - United States Department of Commerce, Bounded by Fourteenth, Fifteenth, and E streets and Constitution Avenue, Washington, District of Columbia, DC

  15. A case of neonatal arterial thrombosis mimicking interrupted aortic arch

    PubMed Central

    Gürsu, Hazım Alper; Varan, Birgül; Oktay, Ayla; Özkan, Murat

    2015-01-01

    Neonatal arterial thrombosis is a very rare entity with clinical findings resembling coarctation of aorta or interrupted aortic arch. A two day-old male newborn was admitted to a different hospital with difficulty in sucking and sleepiness. On echocardiographic examination, a diagnosis of interrupted aortic arch was made and he was treated with prostoglandin E2. When the patient presented to our center, physical examination revealed that his feet were bilaterally cold. The pulses were not palpable and there were ecchymotic regions in the lower extremities. Echocardiography ruled out interrupted aortic arch. Computerized tomographic angiography revealed a large thrombosis and total occlusion of the abdominal aorta. Since there was no response to treatment with tissue plasminogen activator, we performed thrombectomy. Homozygous Factor V Leiden and Methylenetetrahydrofolate reductase mutations were found in this patient. Neonatal aortic thrombosis which is observed very rarely and fatal should be considered in the differential diagnosis of coarctation of aorta and interrupted aortic arch. PMID:26265897

  16. Detail of windows in arched opening on left of east ...

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

    Detail of windows in arched opening on left of east elevation; camera facing west. - Mare Island Naval Shipyard, Rubber Shop, California Avenue, west side across from Dry Dock 1 near Ninth Street, Vallejo, Solano County, CA

  17. LOOKING WEST, BETWEEN READING DEPOT BRIDGE AND SKEW ARCH BRIDGE ...

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

    LOOKING WEST, BETWEEN READING DEPOT BRIDGE AND SKEW ARCH BRIDGE (HAER No. PA-116). - Philadelphia & Reading Railroad, Reading Depot Bridge, North Sixth Street at Woodward Street, Reading, Berks County, PA

  18. Detail view of the decorative arched concrete railing with bushhammered ...

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

    Detail view of the decorative arched concrete railing with bush-hammered inset panels - Pamelia Creek Bridge, Spanning Pamelia Creek at Milepoint 62.78 on North Santiam Highway (OR22), Marion Forks, Linn County, OR

  19. 23. Upstream view of buttress and arch form work and ...

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

    23. Upstream view of buttress and arch form work and construction. Photographer unknown, 1927. Source: MWD. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  20. 19. Upstream face of arches and buttresses at west end. ...

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

    19. Upstream face of arches and buttresses at west end. Photographer unknown, January 29, 1927. Source: MWD. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  1. 65. Close up view of downstream face of arch, buttress ...

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

    65. Close up view of downstream face of arch, buttress ties and roadway support work. Photographer Mark Durben. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  2. 10. Detail view of pendant lamps, laminated arch beams and ...

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

    10. Detail view of pendant lamps, laminated arch beams and ceiling structure, facing north - Mountain Home Air Force Base, Base Chapel, 350 Willow Street, Cantonment Area, Mountain Home, Elmore County, ID

  3. ELEVATION VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, ...

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

    ELEVATION VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, VIEW TO NORTH. - Rex T. Barber Veterans Memorial Bridge, Spanning Crooked River Gorge, Dalles-California Highway (US 97), Terrebonne, Deschutes County, OR

  4. TOPOGRAPHIC VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, ...

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

    TOPOGRAPHIC VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, VIEW TO SOUTHEAST. - Rex T. Barber Veterans Memorial Bridge, Spanning Crooked River Gorge, Dalles-California Highway (US 97), Terrebonne, Deschutes County, OR

  5. PERSPECTIVE VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, ...

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

    PERSPECTIVE VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, VIEW TO NORTH ON WEST SIDE. - Rex T. Barber Veterans Memorial Bridge, Spanning Crooked River Gorge, Dalles-California Highway (US 97), Terrebonne, Deschutes County, OR

  6. 19. COPY OF ENGRAVING OF 'WROUGHT IRON ARCH TRUSS BRIDGE,' ...

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

    19. COPY OF ENGRAVING OF 'WROUGHT IRON ARCH TRUSS BRIDGE,' PAT. DEC. 10, 1867 BY OHIO BRIDGE COMPANY, CLEVELAND, OHIO. (COURTESY OF OHIO HISTORICAL SOCIETY ARCHIVES, COLUMBUS, OHIO) - Tioronda Bridge, South Avenue spanning Fishkill Creek, Beacon, Dutchess County, NY

  7. 11. Southern bridge abutment and arches, taken from old bridge ...

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

    11. Southern bridge abutment and arches, taken from old bridge abutment looking south. - Presumpscot Falls Bridge, Spanning Presumptscot River at Allen Avenue extension, 0.75 mile west of U.S. Interstate 95, Falmouth, Cumberland County, ME

  8. 16. TAILRACE ARCH FROM 1814 MILL BROKEN THROUGH DURING EXCAVATION ...

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

    16. TAILRACE ARCH FROM 1814 MILL BROKEN THROUGH DURING EXCAVATION FOR A SURFACE WATER RUNOFF POLLUTION TRAP, SUBSEQUENTLY FILLED. - Boston Manufacturing Company, 144-190 Moody Street, Waltham, Middlesex County, MA

  9. 10. VIEW OF THE ARCHED TRIPARTITE STEEL SASH WINDOW OF ...

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

    10. VIEW OF THE ARCHED TRIPARTITE STEEL SASH WINDOW OF THE 2ND FLOOR WITH CAST IRON MOLDED PANEL BELOW AT FRONT ELEVATION. - Pacific Telephone & Telegraph Company Building, 1519 Franklin Street, Oakland, Alameda County, CA

  10. 11. VIEW NORTHEAST, DETAIL OF WEST ELEVATION OF TAILRACE ARCH; ...

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

    11. VIEW NORTHEAST, DETAIL OF WEST ELEVATION OF TAILRACE ARCH; BREAK IN MASONRY OF PARAPET PROBABLY INDICATES RAISING OF THE LEVEL OF THE ROADWAY AT THE NORTH END - Windham Road Bridge, Windham Road, spanning Willimantic River, Windham, Windham County, CT

  11. Observations of double arch formation in the Bering Strait

    NASA Astrophysics Data System (ADS)

    Torgerson, Lenora J.; Stringer, William J.

    1985-10-01

    During the time that ice is present in the Bering Strait, it is constantly moving, both northward and southward, subject to wind and current stresses. There were, however, several times in the last decade when the ice was prevented from travelling through the Strait. The blockage of ice was due to the formation of fairly stable double arches that extended across the Strait. Six episodes of double arch formation, resulting in ice blockage in the Bering Strait, were recorded on NOAA satellite imagery spanning the last eleven years; one additional episode was seen on Landsat imagery. All of the incidences of double arching occurred between February and May. In the most extreme case the arches prevented the southward flow of ice through the Strait for at least 27 days during April and May 1980.

  12. DETAIL OF GABLE END WITH ARCHED WINDOW, SHOWING SOFFIT OF ...

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

    DETAIL OF GABLE END WITH ARCHED WINDOW, SHOWING SOFFIT OF OVERHANG; CAMERA FACING NORTH - Mare Island Naval Shipyard, Transportation Building & Gas Station, Third Street, south side between Walnut Avenue & Cedar Avenue, Vallejo, Solano County, CA

  13. Growth and hemodynamics after early embryonic aortic arch occlusion*

    PubMed Central

    Lindsey, Stephanie E.; Menon, Prahlad G.; Kowalski, William J.; Shekhar, Akshay; Yalcin, Huseyin C.; Nishimura, Nozomi; Schaffer, Chris B.; Butcher, Jonathan T.; Pekkan, Kerem

    2015-01-01

    The majority of severe clinically significant forms of congenital heart disease (CHD) is associated with great artery lesions, including hypoplastic, double, right or interrupted aortic arch morphologies. While fetal and neonatal interventions are advancing, their potential ability to restore cardiac function, optimal timing, location, and intensity required for intervention remain largely unknown. We here combine computational fluid dynamics (CFD) simulations with in vivo experiments to test how individual pharyngeal arch artery hemodynamics alters as a result of local interventions to obstruct individual arch artery flow. Simulated isolated occlusions within each pharyngeal arch artery were created with image derived three-dimensional (3D) reconstructions of normal chick pharyngeal arch anatomy at Hamburger-Hamilton (HH) developmental stages HH18 and HH24. Acute flow redistributions were then computed using in vivo measured subject-specific aortic sinus inflow velocity profiles. A kinematic vascular growth-rendering algorithm was then developed and implemented to test the role of changing local wall shear stress patterns in downstream 3D morphogenesis of arch arteries. CFD simulations predicted that altered pressure gradients and flow redistributions were most sensitive to occlusion of the IVth arches. To evaluate these simulations experimentally, a novel in vivo experimental model of pharyngeal arch occlusion was developed and implemented using two-photon microscopy guided femtosecond laser based photodisruption surgery. The right IVth arch was occluded at HH18, and resulting diameter changes were followed for up to 24 hours. Pharyngeal arch diameter responses to acute hemodynamic changes were predicted qualitatively but poorly quantitatively. Chronic growth and adaptation to hemodynamic changes however were predicted in a subset of arches. Our findings suggest that this complex biodynamic process is governed through more complex forms of mechanobiological

  14. [Intraparotid first branchial arch cyst: complex diagnostic and therapeutic process].

    PubMed

    Gilabert Rodríguez, R; Berenguer, B; González Meli, B; Marín Molina, C; de Tomás Palacios, E; Buitrago Weiland, G; Aguado del Hoyo, A

    2013-01-01

    First branchial arch cysts are uncommon. Therefore, together with its variable clinical and age presentation they are often misdiagnosed at first. The treatment is surgical, requiring a correct procedure to avoid future recurrences. In this paper we describe a typical case of first branchial arch cyst in which as described in other reports, we first made several misdiagnoses and therefore an inadequate treatment and lastly, with the correct diagnosis, we performed a meticulous complete excision under facial nerve monitoring. PMID:23833927

  15. Clarifying the anatomy of the fifth arch artery

    PubMed Central

    Gupta, Saurabh Kumar; Gulati, Gurpreet Singh; Anderson, Robert H

    2016-01-01

    The artery allegedly forming in the fifth pharyngeal arch has increasingly been implicated as responsible for various vascular malformations in patients with congenitally malformed hearts. Observations from studies on developing embryos, however, have failed to provide support to substantiate several of these inferences such that the very existence of the fifth arch artery remains debatable. To the best of our knowledge, in only a solitary human embryo has a vascular channel been found that truly resembled the artery of the fifth arch. Despite the meager evidence to support its existence, the fifth arch artery has been invoked to explain the morphogenesis of double-barreled aorta, some unusual forms of aortopulmonary communications, and abnormalities of the brachiocephalic arteries. In most of these instances, the interpretations have proved fallible when examined in the light of existing knowledge of cardiac development. In our opinion, there are more plausible alternative explanations for the majority of these descriptions. Double-barreled aorta is more likely to result from retention of the recently identified dorsal collateral channels while abnormalities of brachiocephalic arteries are better explained on the basis of extensive remodeling of aortic arches during fetal development. Some examples of aortopulmonary communications, nonetheless, may well represent persistence of the developing artery of the fifth pharyngeal arch. We here present one such case — a patient with tetralogy of Fallot and pulmonary atresia, in whom the fifth arch artery provided a necessary communication between the ascending aorta and the pulmonary arteries. In this light, we discuss the features we consider to be essential before attaching the tag of “fifth arch artery” to a candidate vascular channel. PMID:27011696

  16. A comparison of four methods of predicting arch length.

    PubMed

    Gardner, R B

    1979-04-01

    1. Four arch length prediction equations (Nance, Johnston-Tanaka, Moyers, and Hixon-Oldfather) were compared by examining pretreatment casts, pretreatment intraoral radiographs, and posttreatment casts of forty-one patients of mixed-dentition age. 2. A comparison of correlation coefficients and slopes of the predicted arch length versus the actual arch lengths revealed that the Hixon-Oldfather method conformed closest to the ideal. 3. No combination of the four methods produced a more accurate equation than the single most accurate method. 4. Neither the sex of the patient nor the type of occlusion affected the prediction accuracy of any of the four equations. 5. All methods tend to overpredict the arch length size by 1 to 3 mm., with the exception of the Hixon-Oldfather equation, which underpredicted by approximately 0.5 mm. 6. An analysis of the intrainvestigator error showed a very low standard error of estimate for individual tooth measurements and for the prediction values. 7. A variance analysis showed that most of the variation was due to arch length (85%), a slight amount was due to the prediction method (8%), and 6% of the variation was due to the rater. 8. A low correlation was found between space available versus actual discrepancy and space available versus actual arch length. 9. High correlation coefficients were found for the predicted arch lengths when compared with the actual arch lengths. As expected, the correlation coefficients for the predicted widths of only the canines and premolars compared with the actual widths were not quite as high. PMID:285614

  17. The mathematical model of the chevron-arch gearing transmitter

    NASA Astrophysics Data System (ADS)

    Bubenchikov, Aleksey; Bubenchikov, Mikhail; Matvienko, Oleg; Shcherbakov, Nikolay

    2016-01-01

    The teeth of herringbone transmission wheels are obtained by docking two helical wheels with an opposite arrangement of teeth, which can solve the problem of the axial force. The mathematical model of coupling chevron teeth of the driving wheel in the area of their docking using the arch tooth fragment is developed. The conjugacy area surface of the driven wheel chevron teeth is obtained as the envelope of the surfaces family formed by the arched tooth during the process of the parts motion.

  18. Comparison of arch forms between Turkish and North American

    PubMed Central

    Celebi, Ahmet A.; Keklik, Hakan; Tan, Enes; Ucar, Faruk I.

    2016-01-01

    ABSTRACT Objective: The aim of this study was to clarify the morphological differences in the mandibular arches of Turkish and North American white subjects. Methods: The sample included 132 Turkish (34 Class I, 58 Class II, and 40 Class III) and 160 North American (60 Class I, 50 Class II, and 50 Class III) subjects. The most facial portion of 13 proximal contact areas was digitized from photocopied images of patients' mandibular dental arches. Clinical bracket points were calculated for each tooth based on mandibular tooth thickness data. Four linear and two proportional measurements were taken. The subjects were grouped according to arch form types (tapered, ovoid and square) in order to have frequency distribution compared between ethnic groups in each Angle classification. Results: The Turkish group showed significantly lower molar depth and more significant molar width-depth (W/D) ratio in all three Angle classifications. On the other hand, the Turkish group also showed a significantly larger intercanine width in Class III malocclusion and intermolar width in Class II malocclusion. The most frequent arch forms seen were the ovoid arch form in the Turkish group and the tapered form in the white group. Conclusions: Our results demonstrate that when treating Turkish patients, one should expect to use preformed ovoid arch form orthodontic wires in a significant percentage of patients. PMID:27275615

  19. Monitoring system of arch bridge for safety network management

    NASA Astrophysics Data System (ADS)

    Joo, Bong Chul; Yoo, Young Jun; Lee, Chin Hyung; Park, Ki Tae; Hwang, Yoon Koog

    2010-03-01

    Korea has constructed the safety management network monitoring test systems for the civil infrastructure since 2006 which includes airport structure, irrigation structure, railroad structure, road structure, and underground structure. Bridges among the road structure include the various superstructure types which are Steel box girder bridge, suspension bridge, PSC-box-girder bridge, and arch bridge. This paper shows the process of constructing the real-time monitoring system for the arch bridge and the measured result by the system. The arch type among various superstructure types has not only the structural efficiency but the visual beauty, because the arch type superstructure makes full use of the feature of curve. The main measuring points of arch bridges composited by curved members make a difference to compare with the system of girder bridges composited by straight members. This paper also shows the method to construct the monitoring system that considers the characteristic of the arch bridge. The system now includes strain gauges and thermometers, and it will include various sensor types such as CCTV, accelerometers and so on additionally. For the long term and accuracy monitoring, the latest optical sensors and equipments are applied to the system.

  20. Investigation of complete dental arches of 23 patients aged at least 75 years

    PubMed Central

    Volpato, Beniamino; Di Carlo, Stefano; Shahinas, Jorida; Mencio, Francesca; Fusco, Raimondo; Pompa, Giorgio

    2012-01-01

    Summary Numerous factors help to conserve the dentition of elderly patients, such as healthy food habits, a strong physical constitution, and a good quality of life. The aim of this study was to define a model that takes into account the integration of both the structural and functional aspects of a healthy dentition. Twenty-three patients aged at least 75 years were recruited. The patients were required to possess all of their dentition and have no prosthetic rehabilitations and be asymptomatic for temporomandibular joint disorders. Occlusal characteristics were measured and recorded using the criteria adopted by the US National Health and Nutrition Examination Survey: presence or absence of rotation of the upper arches, trend of the occlusal table, and distribution of occlusal contacts during movements. We believe that the following parameters are predictive of a condition of the dental arches’ equilibrium: crowding and disalignment of the teeth, derotated position of the upper arches, absence of the curve of Spee, an occlusal plane trend contrary to spherical theory, and presence of group function on the working side and malocclusion on the nonworking side. We consider that these factors are merely the consequence of correct functioning within the framework of favorable environmental factors. PMID:22545185

  1. Stress propagation and Arching in Static Sandpiles

    NASA Astrophysics Data System (ADS)

    Wittmer, J. P.; Cates, M. E.; Claudin, P.

    1997-01-01

    , stresses propagate along a nested set of archlike structures within the pile, resulting in a minimum of the vertical normal stress beneath the apex of the pile, as seen experimentally (“the dip”). This experiment has not been explained within previous continuum approaches; the appearance of arches within our model corroborates earlier physical arguments (of S.F. Edwards and others) as to the origin of the dip, and places them on a more secure mathematical footing. The second models is that of “oriented stress linearity” (OSL) which contains an adjustable parameter (one value of which corresponds to FPA). For the general OSL case, the simple interpretation in terms of nested arches does not apply, though a dip is again found over a finite parameter range. In three dimensions, the choice for the primary constitutive relation must be supplemented by a secondary one; we have tried several, and find that the results for the stresses in a three-dimensional (conical) pile do not depend much on which secondary closure is chosen. Three-dimensional results for the FPA model are in good semiquantitative agreement with published experimental data on conical piles (including the dip); the data does not exclude, but nor does it support, OSL parameters somewhat different from FPA. The modelling strategy we adopt, based on local, history-dependent constitutive relations among stresses, leads to nontrivial predictions for piles which are prepared with a different construction history from the normal one. We consider several such histories in which a pile is prepared and parts of it then removed and/or tilted. Experiments along these lines could provide a searching test of the theory.

  2. Generation of electromagnetic emission during the injection of dense supersonic plasma flows into arched magnetic field

    NASA Astrophysics Data System (ADS)

    Viktorov, Mikhail; Golubev, Sergey; Mansfeld, Dmitry; Vodopyanov, Alexander

    2016-04-01

    Interaction of dense supersonic plasma flows with an inhomogeneous arched magnetic field is one of the key problems in near-Earth and space plasma physics. It can influence on the energetic electron population formation in magnetosphere of the Earth, movement of plasma flows in magnetospheres of planets, energy release during magnetic reconnection, generation of electromagnetic radiation and particle precipitation during solar flares eruption. Laboratory study of this interaction is of big interest to determine the physical mechanisms of processes in space plasmas and their detailed investigation under reproducible conditions. In this work a new experimental approach is suggested to study interaction of supersonic (ion Mach number up to 2.7) dense (up to 1015 cm‑3) plasma flows with inhomogeneous magnetic field (an arched magnetic trap with a field strength up to 3.3 T) which opens wide opportunities to model space plasma processes in laboratory conditions. Fully ionized plasma flows with density from 1013 cm‑3 to 1015 cm‑3 are created by plasma generator on the basis of pulsed vacuum arc discharge. Then plasma is injected in an arched open magnetic trap along or across magnetic field lines. The filling of the arched magnetic trap with dense plasma and further magnetic field lines break by dense plasma flow were experimentally demonstrated. The process of plasma deceleration during the injection of plasma flow across the magnetic field lines was experimentally demonstrated. Pulsed plasma microwave emission at the electron cyclotron frequency range was observed. It was shown that frequency spectrum of plasma emission is determined by position of deceleration region in the magnetic field of the magnetic arc, and is affected by plasma density. Frequency spectrum shifts to higher frequencies with increasing of arc current (plasma density) because the deceleration region of plasma flow moves into higher magnetic field. The observed emission can be related to the

  3. Aplicación del Teorema de Nekhorochev para tiempos de estabilidad en Mecánica Celeste

    NASA Astrophysics Data System (ADS)

    Miloni, O.; Núñez, J.; Brunini, A.

    En Mecánica Celeste, uno de los problemas centrales consiste en la determinación de los tiempos de estabilidad. El teorema de Nekhorochev proporciona un método para dicho estudio, para un sistema determinado por un hamiltoniano descripto en las variables acción-ángulo. El trabajo consiste en la acotación tanto del potencial perturbador y de la matriz hessiana del hamiltoniano integrable para determinar luego el tiempo de estabilidad de dicho sistema, donde por estabilidad se entiende la separación en norma infinito en el espacio de las acciones.

  4. Branched and fenestrated options to treat aortic arch aneurysms.

    PubMed

    Maurel, Blandine; Mastracci, Tara M; Spear, Rafaelle; Hertault, Adrien; Azzaoui, Richard; Sobocinski, Jonathan; Haulon, Stephan

    2016-10-01

    Conventional surgical repair of aortic arch aneurysms using cardiopulmonary bypass and hypothermic circulatory arrest remains the gold standard, however it is associated with a substantial mortality and morbidity rate, especially in the elderly. Hybrid techniques avoid aortic cross-clamping and circulatory arrest, but are of limited use and are only applicable to selected patients. The development of new devices to treat aortic arch aneurysms endovascularly has the potential to offer a treatment modality to patients unfit for an open repair. We present the challenges specific to endovascular arch repair based on our experience and the literature available from the first experience in 1999 to the third generation graft currently commonly used. Following an initial learning curve associated with the use of the third generation arch branch device, along with careful patient selection and operator experience, early results are promising. Technical success was achieved in all cases, there was no early mortality and strokes were noted in 11%. As with branched and fenestrated technology for thoracoabdominal aneurysm repair, the use of total endovascular repair for arch pathology will require an evolution in endovascular practice and device design. However, at present, the early use of the latest generation device offers a novel approach to patients who previously had no surgical options. PMID:27332680

  5. Muscular axillary arch accompanying variation of the musculocutaneous nerve: axillary arch

    PubMed Central

    Jung, Soo-Jung; Lee, Hyunsu; Choi, In-Jang

    2016-01-01

    Continuous attention has been developed on the anatomical variations of the axilla in anatomist and surgeon due to their clinical importance. The axillary region is an anatomical space between the lateral part of the chest wall and the medial aspect of the upper limb. During the routine dissection of embalmed cadavers, we found variant muscular slip originating from the lateral border of tendinous part of the latissimus dorsi and continuing 9 cm more crossing the axilla. And then, it inserted into the superior margin of the insertion of the pectoralis major. We considered this muscular variation as axillary arch muscle. Correct identification of the relevant anatomy and subsequent simple surgical division is curative, paying special attention to anatomical variations in this region and its clinical importance due to its close relationship to the neurovascular elements of the axilla. PMID:27382519

  6. Some mice feature 5th pharyngeal arch arteries and double-lumen aortic arch malformations.

    PubMed

    Geyer, Stefan H; Weninger, Wolfgang J

    2012-01-01

    A 5th pair of pharyngeal arch arteries (PAAs) has never been identified with certainty in mice. Murines in general are considered to not develop a 5th pair. If true, the significance of the mouse as a model for researching the genesis of malformations of the great intrathoracic arteries is limited. We aimed to investigate whether mouse embryos develop a 5th pair of PAAs and to identify malformations known to be caused by defective remodelling of the 5th PAAs. We employed the high-resolution episcopic microscopy method for creating digital volume data and three-dimensional (3D) computer models of the great intrathoracic arteries of 30 mouse embryos from days 12-12.5 post conception and 180 mouse fetuses from days 14.5 and 15.5 post conception. The 3D models of the fetuses were screened for the presence of a double-lumen aortic arch malformation. We identified such a malformation in 1 fetus. The 3D models of the embryos were analysed for the presence of 5th PAAs. Six of the 30 embryos (20%) showed a 5th PAA bilaterally, and an additional 9 (30%) showed a 5th PAA unilaterally. Our results prove that some mice do develop a 5th pair of PAAs. They also show that malformations which occur rarely in humans and result from defective remodelling of the left 5th PAA can be identified in mice as well. Thus, the mouse does represent an excellent model for researching the mechanisms driving PAA remodelling and the genesis of malformations of the great intrathoracic arteries. PMID:22287557

  7. Evaluation of dental arch width and form changes after orthodontic treatment and retention with a new computerized method.

    PubMed

    Taner, Tülin Ugur; Ciger, Semra; El, Hakan; Germeç, Derya; Es, Alphan

    2004-10-01

    The purpose of this study was to evaluate longitudinal arch width and form changes and to define arch form types with a new computerized method. Maxillary and mandibular models of 21 Class II Division 1 patients were examined before treatment (T(0)), after treatment (T(1)), and an average of 3 years after retention (T(2)). Arch width measurements were made directly on scanned images of maxillary and mandibular models. Arch form changes at T(0)-T(1) and T(1)-T(2) were evaluated by superimposing the computer-generated Bezier arch curves with a computer program. Types of dental arch forms were defined by superimposing them with the pentamorphic arch system, which included 5 different types of arch forms: normal, ovoid, tapered, narrow ovoid, and narrow tapered. Maxillary arch widths were increased during orthodontic treatment. Mandibular posterior arch widths were also increased. The expansion of the mandibular arch forms was less than in the maxillary arch forms. Arch width changes were generally stable, except for reduction in maxillary and mandibular interlateral, inter-first premolar, and mandibular intercanine widths. Pretreatment maxillary arch forms were mostly tapered; mandibular arch forms were tapered and narrow tapered. In maxillary arch forms, 76% of the treatment changes were maintained. Mandibular arch form was maintained in 67% of the sample, both during treatment and after retention. In mandibular arches, 71% of orthodontically induced arch form changes were maintained. PMID:15470349

  8. Ascending Aortic Slide for Interrupted Aortic Arch Repair.

    PubMed

    Urencio, Miguel; Dodge-Khatami, Ali; Greenleaf, Chris E; Aru, Giorgio; Salazar, Jorge D

    2016-09-01

    For repair of interrupted aortic arch, unfavorable anatomy challenges a tension-free anastomosis. We describe a useful alternative surgical technique used in five neonates/infants, involving splitting the ascending aorta from the sinotubular junction to the arch origin, leftward and posterior "sliding" of the flap with anastomosis to the distal arch creating a native tissue bridge, and reconstruction with a patch. With wide interruption gaps between proximal and distal aortic portions, the ascending aortic slide is a safe and reproducible technique, providing a tension-free native tissue bridge with potential for growth, and a scaffold for patch augmentation in biventricular hearts, or for Norwood stage I in univentricular palliation. PMID:27587504

  9. Numerical Modelling of Soil Arching in a Shallow Backfill Layer

    NASA Astrophysics Data System (ADS)

    Szajna, Waldemar St.

    2015-03-01

    The paper presents the application of the finite element method into the modelling of soil arching. The phenomenon plays fundamental role in soil-shell flexible structures behaviour. To evaluate the influence of arching on a pressure reduction, a plain strain trapdoor under a shallow layer of backfill was simulated. The Coulomb-Mohr plasticity condition and the nonassociated flow rule were used for the soil model. The research examines the impact of the internal friction angle and the influence of the backfill layer thickness on the value of soil arching. The carried out analyses indicate that the reduction of pressures acting on a structure depends on the value of the internal friction angle, which confirms the earlier research. For a shallow backfill layer however, the reduction is only a local phenomenon and can influence only a part of the structure.

  10. The development and evolution of the pharyngeal arches

    PubMed Central

    GRAHAM, ANTHONY

    2001-01-01

    A muscularised pharynx, with skeletal support, serving the dual functions of feeding and respiration, is a fundamental vertebrate characteristic. Embryologically, the pharyngeal apparatus has its origin in a series of bulges that form on the lateral surface of the embryonic head, the pharyngeal arches, whose development is complex. These structures are composed of a number of disparate embryonic cell types: ectoderm, endoderm, neural crest and mesoderm, whose development must be coordinated to generate the functional adult apparatus. In the past, most studies have emphasised the role played by the neural crest, which generates the skeletal elements of the arches, in directing pharyngeal arch development, but it has also become apparent that the endoderm plays a prominent role in directing arch development. Neural crest cells are not required for arch formation, their regionalisation nor to some extent their sense of identity. Furthermore, the endoderm is the major site of expression of a number of important signalling molecules, and this tissue has been shown to be responsible for promoting the formation of particular components of the arches. Thus vertebrate pharyngeal morphogenesis can now be seen to be a more complex process than was previously believed, and must result from an integration of both neural crest and endodermal patterning mechanisms. Interestingly, this also mirrors the fact that the evolutionary origin of pharyngeal segmentation predates that of the neural crest, which is an exclusively vertebrate characteristic. As such, the evolution of the vertebrate pharynx is also likely to have resulted from an integration between these 2 patterning systems. Alterations in the interplay between neural crest and endodermal patterning are also likely to be responsible for the evolutionary that occurred to the pharyngeal region during subsequent vertebrate evolution. PMID:11523815

  11. The Hindfoot Arch: What Role Does the Imager Play?

    PubMed

    Lin, Yu-Ching; Kwon, John Y; Ghorbanhoseini, Mohammad; Wu, Jim S

    2016-09-01

    Flatfoot deformity is a common disorder of the foot and ankle and is caused by loss of the hindfoot arch. Radiologists and clinicians should be familiar with the anatomy and the imaging criteria used to assess injury to the supporting structures. Radiographs and computed tomography are most useful in characterizing the degree of osseous deformity and ultrasonography and magnetic resonance imaging are most useful in the evaluation of the supporting soft tissue structures. Treatment depends on the clinical symptoms and involves restoring the normal biomechanics of the hindfoot arch through strengthening exercises, foot/ankle orthotics, and surgery. PMID:27545430

  12. Quantifying the dynamic evolution of individual arched magnetic flux tubes

    NASA Astrophysics Data System (ADS)

    Stenson, E. V.; Bellan, P. M.

    2012-12-01

    Highly dynamic arched ‘loops’ of plasma were created in the laboratory with a magnetized plasma gun. The magnetic structure of the loops was found to be consistent with that of an expanding flux tube subject to a kink instability. High-speed flows were found to transport plasma along the loop axis, from both footpoints toward the apex of the arched loop. Two complementary MHD models were used to explain the expansion and axial flows, both of which scale in proportion to a ‘toroidal Alfven speed’.

  13. Multimodality imaging assessment for Thoraflex hybrid total arch replacement.

    PubMed

    Wong, Randolph Hl; Ho, Jacky Yk; Underwood, Malcolm J

    2016-06-01

    Conventionally, aortic pathologies involving the ascending, arch, and descending thoracic aorta are treated by a staged operation. The Thoraflex device is a composite 4-branched graft with a distal endovascular stent, which allows one-stage treatment of these pathologies. We describe our multimodality hybrid approach for total arch replacement using the Thoraflex device with the adjunct of intraoperative 3-dimensional transesophageal echocardiography, Endo-EYE endoscopy, and on-table aortography in a hybrid operating room. These multimodality assessments can ascertain adequate sealing of a distal aortic tear and proper opening of the endograft, and provide on-table functional assessment of false lumen hemodynamics. Early results are promising. PMID:27072867

  14. Getting Freshman in Equilibrium.

    ERIC Educational Resources Information Center

    Journal of Chemical Education, 1983

    1983-01-01

    Various aspects of chemical equilibrium were discussed in six papers presented at the Seventh Biennial Conference on Chemical Education (Stillwater, Oklahoma 1982). These include student problems in understanding hydrolysis, helping students discover/uncover topics, equilibrium demonstrations, instructional strategies, and flaws to kinetic…

  15. Comparison of arch form between ethnic Malays and Malaysian Aborigines in Peninsular Malaysia

    PubMed Central

    Xinwei, Eunice Soh; Lim, Sheh Yinn; Jamaludin, Marhazlinda; Mohamed, Nor Himazian; Yusof, Zamros Yuzaidi Mohd; Shoaib, Lily Azura; Nik Hussein, Nik Noriah

    2012-01-01

    Objective To determine and compare the frequency distribution of various arch shapes in ethnic Malays and Malaysian Aborigines in Peninsular Malaysia and to investigate the morphological differences of arch form between these two ethnic groups. Methods We examined 120 ethnic Malay study models (60 maxillary, 60 mandibular) and 129 Malaysian Aboriginal study models (66 maxillary, 63 mandibular). We marked 18 buccal tips and incisor line angles on each model, and digitized them using 2-dimensional coordinate system. Dental arches were classified as square, ovoid, or tapered by printing the scanned images and superimposing Orthoform arch templates on them. Results The most common maxillary arch shape in both ethnic groups was ovoid, as was the most common mandibular arch shape among ethnic Malay females. The rarest arch shape was square. Chi-square tests, indicated that only the distribution of the mandibular arch shape was significantly different between groups (p = 0.040). However, when compared using independent t-tests, there was no difference in the mean value of arch width between groups. Arch shape distribution was not different between genders of either ethnic group, except for the mandibular arch of ethnic Malays. Conclusions Ethnic Malays and Malaysian Aborigines have similar dental arch dimensions and shapes. PMID:23112931

  16. Comparison of arch forms between Korean and North American white populations.

    PubMed

    Kook, Yoon-Ah; Nojima, Kunihiko; Moon, Hong-Beom; McLaughlin, Richard P; Sinclair, Peter M

    2004-12-01

    The purpose of this study was to evaluate morphologic differences in the mandibular arches of Korean and North American white subjects. The subjects were grouped according to arch form (tapered, ovoid, and square) to compare the frequency distribution of the 3 arch forms between the ethnic groups in each Angle classification. The sample included 160 white (60 Class I, 50 Class II, and 50 Class III) and 368 Korean (114 Class I, 119 Class II, and 135 Class III) subjects. The most facial portion of 13 proximal contact areas was digitized from photocopied images of the mandibular dental arches. Clinical bracket points were calculated for each tooth according to mandibular tooth thickness data, and then 4 linear and 2 proportional measurements were taken. Arch width was statistically significantly smaller in the white group than in the Korean group, but arch depth did not differ. In the Korean group, the most frequent arch form was square, whereas in the white group the tapered arch form predominated. When the subjects were regrouped by arch form, the Korean arches had a tendency to be larger and deeper than the white arches within each of the 3 arch form types. PMID:15592215

  17. 48. Readying arch of bridge 5600006P for concrete pout. Railroad ...

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

    48. Readying arch of bridge 5600-006P for concrete pout. Railroad iron for arch support is secured by bedding rails in concrete. - Vicksburg National Military Park Roads & Bridges, Melan Arch Bridges, Spanning various tributaries at Confederate Avenue, Vicksburg, Warren County, MS

  18. How to Perfuse: Concepts of Cerebral Protection during Arch Replacement

    PubMed Central

    Habertheuer, Andreas; Wiedemann, Dominik; Kocher, Alfred; Laufer, Guenther; Vallabhajosyula, Prashanth

    2015-01-01

    Arch surgery remains undoubtedly among the most technically and strategically challenging endeavors in cardiovascular surgery. Surgical interventions of thoracic aneurysms involving the aortic arch require complete circulatory arrest in deep hypothermia (DHCA) or elaborate cerebral perfusion strategies with varying degrees of hypothermia to achieve satisfactory protection of the brain from ischemic insults, that is, unilateral/bilateral antegrade cerebral perfusion (ACP) and retrograde cerebral perfusion (RCP). Despite sophisticated and increasingly individualized surgical approaches for complex aortic pathologies, there remains a lack of consensus regarding the optimal method of cerebral protection and circulatory management during the time of arch exclusion. Many recent studies argue in favor of ACP with various degrees of hypothermic arrest during arch reconstruction and its advantages have been widely demonstrated. In fact ACP with more moderate degrees of hypothermia represents a paradigm shift in the cardiac surgery community and is widely adopted as an emergent strategy; however, many centers continue to report good results using other perfusion strategies. Amidst this important discussion we review currently available surgical strategies of cerebral protection management and compare the results of recent European multicenter and single-center data. PMID:26713319

  19. Double arch mirror study. Part 2: Engineering analysis report

    NASA Technical Reports Server (NTRS)

    Iraninejad, B.; Vukobratovich, D.

    1983-01-01

    A method of mounting a cryogenically cooled, lightweight, double arch, class mirror for infrared, astronomical telescopes was developed. A 50 cm, fused silica mirror was modified for use in a new mount configuration. The flexures and the finite element analysis of the mirror stresses are reported.

  20. 6. OPEN HEARTH NO. 4 TRESTLE. THE ARCH WITH THE ...

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

    6. OPEN HEARTH NO. 4 TRESTLE. THE ARCH WITH THE GATE IS KNOWN AS THE HOLE IN THE WALL BY FORMER STEELWORKERS. FOR YEARS THE HOLE IN THE WALL PROVIDED ACCESS TO THE INTERIOR OF THE MILL AND TO THE PAYMASTER'S OFFICE. (Martin Stupich) - U.S. Steel Homestead Works, Open Hearth Steelmaking Plant, Along Monongahela River, Homestead, Allegheny County, PA

  1. 1. GORGE HIGH DAM. THIS THIN ARCH DAM WITH A ...

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

    1. GORGE HIGH DAM. THIS THIN ARCH DAM WITH A GRAVITY SECTION IS THE THIRD DAM BUILT BY SEATTLE CITY LIGHT TO PROVIDE WATER FOR GORGE POWERHOUSE AND WAS COMPLETED IN 1961, 1989. - Skagit Power Development, Gorge High Dam, On Skagit River, 2.9 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  2. 15. Reinforced Concrete Arch over Truckee River at Reno, Nevada. ...

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

    15. Reinforced Concrete Arch over Truckee River at Reno, Nevada. January 28, 1920. C. R. Hill, Consulting Engineer, Reno, Nevada. Various sectional and detail views of railings. lamp posts, and brackets. Paper (same as NV-10-13 and NV-10-14). Drawing No. B-73 (VB-10-26). - Riverside Bridge, Spanning Truckee River at Booth Street, Reno, Washoe County, NV

  3. 14. Reinforced Concrete Arch over Truckee River at Reno, Nevada. ...

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

    14. Reinforced Concrete Arch over Truckee River at Reno, Nevada. January 24, 1920. C. R. Hill, Consulting Engineer, Reno, Nevada. Various plan, section, and detail views. Paper (same as NV-10-13). Drawing No. B-72 (VB-10-25) - Riverside Bridge, Spanning Truckee River at Booth Street, Reno, Washoe County, NV

  4. INTERIOR DETAIL, SECONDSTORY JOISTS, SUBFLOORING, AND FIREPLACE HEARTH RELIEVING ARCH. ...

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

    INTERIOR DETAIL, SECOND-STORY JOISTS, SUBFLOORING, AND FIREPLACE HEARTH RELIEVING ARCH. THESE FEATURES WERE MADE VISIBLE AFTER A 2002 FAILURE OF WHAT WAS LIKELY THE ORIGINAL EIGHTEENTH-CENTURY CEILING PLASTER IN THE SOUTHWEST CABINET - The Woodlands, 4000 Woodlands Avenue, Philadelphia, Philadelphia County, PA

  5. 10. MARBLE BRIDGE MIDSPAN OF EAST ARCH. THE PLATE READS ...

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

    10. MARBLE BRIDGE MIDSPAN OF EAST ARCH. THE PLATE READS MORRIS RUN BRIDGE, 1908, C.F. MOYER, C.Y. STRADLINGS, S.M. FITE, COMMRR'S, S.B. TWINING CO. CONTR, W. CADWALLADER CLERK. - Morris Run Bridge, Rickert Road (TR 417) spanning Morris Run in Hilltown Township, Dublin, Bucks County, PA

  6. 26. VIEW SHOWING NEEDLE VALVE TRASH RACK NEARING COMPLETION. ARCHES ...

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

    26. VIEW SHOWING NEEDLE VALVE TRASH RACK NEARING COMPLETION. ARCHES VISIBLE IN THIS PICTURE ARE 8, 9, 10, AND 11, WHICH HAVE BEEN COMPLETED TO SPRINGING LINE ELEVATIONS 1700, 1744, 1766 AND 1766 RESPECTIVELY. January 1, 1939 - Bartlett Dam, Verde River, Phoenix, Maricopa County, AZ

  7. Capabilites of an arch element for correcting conformal optical domes

    NASA Astrophysics Data System (ADS)

    Sparrold, Scott W.; Knapp, David J.; Manhart, Paul K.; Elsberry, Kevin W.

    1999-10-01

    This paper presents an approach for correcting conformal missile domes with a non-rotationally symmetric optical element called an arch. A parametric study in terms of aerodynamics, fineness ratio, maximum seeker look angle and dome index of refraction will demonstrate its capabilities for correcting conformal domes. A nomograph for trading optical performance versus relative missile range will also be presented.

  8. View looking to the arched entrances that divide the Departmental ...

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

    View looking to the arched entrances that divide the Departmental Auditorium from the Interstate Commerce Commission (east) and U.S. Customs Agency (originally Labor Department to the west) - Departmental Auditorium, Constitution Avenue between Twelfth and Fourteenth Streets, Washington, District of Columbia, DC

  9. 5. BASEMENT OF FRONT HOUSE, SHOWING BRICK ARCHES CARRYING ALLEY ...

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

    5. BASEMENT OF FRONT HOUSE, SHOWING BRICK ARCHES CARRYING ALLEY ABOVE (LEFT) AND STONE FOUNDATION OF CENTRAL CHIMNEY STACK (RIGHT). Photo by Theodore F. Dillon, August 1960 - Captain James Abercrombie House, 268-270 South Second Street, Philadelphia, Philadelphia County, PA

  10. 35. Photo of concrete arch culvert constructed by Puget Sound ...

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

    35. Photo of concrete arch culvert constructed by Puget Sound Construction Company, 1911, for the Northern Pacific Railroad, over flume. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  11. ArchDB 2014: structural classification of loops in proteins

    PubMed Central

    Bonet, Jaume; Planas-Iglesias, Joan; Garcia-Garcia, Javier; Marín-López, Manuel A.; Fernandez-Fuentes, Narcis; Oliva, Baldo

    2014-01-01

    The function of a protein is determined by its three-dimensional structure, which is formed by regular (i.e. β-strands and α-helices) and non-periodic structural units such as loops. Compared to regular structural elements, non-periodic, non-repetitive conformational units enclose a much higher degree of variability—raising difficulties in the identification of regularities, and yet represent an important part of the structure of a protein. Indeed, loops often play a pivotal role in the function of a protein and different aspects of protein folding and dynamics. Therefore, the structural classification of protein loops is an important subject with clear applications in homology modelling, protein structure prediction, protein design (e.g. enzyme design and catalytic loops) and function prediction. ArchDB, the database presented here (freely available at http://sbi.imim.es/archdb), represents such a resource and has been an important asset for the scientific community throughout the years. In this article, we present a completely reworked and updated version of ArchDB. The new version of ArchDB features a novel, fast and user-friendly web-based interface, and a novel graph-based, computationally efficient, clustering algorithm. The current version of ArchDB classifies 149,134 loops in 5739 classes and 9608 subclasses. PMID:24265221

  12. 3D Stretchable Arch Ribbon Array Fabricated via Grayscale Lithography

    PubMed Central

    Pang, Yu; Shu, Yi; Shavezipur, Mohammad; Wang, Xuefeng; Mohammad, Mohammad Ali; Yang, Yi; Zhao, Haiming; Deng, Ningqin; Maboudian, Roya; Ren, Tian-Ling

    2016-01-01

    Microstructures with flexible and stretchable properties display tremendous potential applications including integrated systems, wearable devices and bio-sensor electronics. Hence, it is essential to develop an effective method for fabricating curvilinear and flexural microstructures. Despite significant advances in 2D stretchable inorganic structures, large scale fabrication of unique 3D microstructures at a low cost remains challenging. Here, we demonstrate that the 3D microstructures can be achieved by grayscale lithography to produce a curved photoresist (PR) template, where the PR acts as sacrificial layer to form wavelike arched structures. Using plasma-enhanced chemical vapor deposition (PECVD) process at low temperature, the curved PR topography can be transferred to the silicon dioxide layer. Subsequently, plasma etching can be used to fabricate the arched stripe arrays. The wavelike silicon dioxide arch microstructure exhibits Young modulus and fracture strength of 52 GPa and 300 MPa, respectively. The model of stress distribution inside the microstructure was also established, which compares well with the experimental results. This approach of fabricating a wavelike arch structure may become a promising route to produce a variety of stretchable sensors, actuators and circuits, thus providing unique opportunities for emerging classes of robust 3D integrated systems. PMID:27345766

  13. 27. Spans 25, detail view, eastern spring of northern arch ...

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

    27. Spans 2-5, detail view, eastern spring of northern arch rib of Span 5 at east abutment, showing exposed structural steel; view to southwest. - Fifth Street Bridge, Spanning MBTA Fitchburg Commuter Rail Line tracks, Conrail Fitchburg Secondary Line & North Nashua River, Fitchburg, Worcester County, MA

  14. ATM/cable arch and beam structural test program

    NASA Technical Reports Server (NTRS)

    Housley, J. A.

    1972-01-01

    The structural testing is described of an Apollo Telescope Mount (ATM) cable arch and beam assembly, using static loads to simulate the critical conditions expected during transportation and launch of the ATM. All test objectives were met. Stress and deflection data show that the assembly is structurally adequate for use in the ATM.

  15. Persistent right aortic arch in a yearling horse.

    PubMed Central

    Butt, T D; MacDonald, D G; Crawford, W H; Dechant, J E

    1998-01-01

    A 14-month-old filly with chronic pharyngitis was diagnosed with incomplete esophageal constriction and megaesophagus due to a persistent right aortic arch. This report is unusual because clinical signs of respiratory dysfunction secondary to chronic regurgitation occurred prior to the recognition of dysphagia. PMID:9818140

  16. 2. CONTEXT SHOT LOOKING NORTH, WITH BUILDING 8250 (ARCH HANGAR ...

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

    2. CONTEXT SHOT LOOKING NORTH, WITH BUILDING 8250 (ARCH HANGAR IN BACKGROUND AND STEAM PIPES BENDING OVER RAILROAD TRACKS IN MIDDLE GROUND. - Loring Air Force Base, Double Cantilever Hangar, East of Arizona Road, west of southern portion of Taxiway J, Limestone, Aroostook County, ME

  17. Towering Magnetic Arches Seen by NASA’s SDO

    NASA Video Gallery

    Arches of magnetic field lines towered over the sun’s edge as a pair of active regions began to rotate into view in this video captured by NASA’s Solar Dynamics Observatory on April 5-6, 2016. Acti...

  18. View of openspandrel concrete arch that carries the road crossing ...

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

    View of open-spandrel concrete arch that carries the road crossing Grand Coulee Dam over the spillways, looking west. Note the drum gate in its nearly fully raised position. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  19. Hemodynamics in the Cephalic Arch of a Brachiocephalic Fistula

    PubMed Central

    Boghosian, M.; Cassel, K.; Hammes, M.; Funaki, B.; Kim, S.; Qian, X.; Wang, X.; Dhar, P.; Hines, J.

    2014-01-01

    The care and outcome of patients with end stage renal disease (ESRD) on chronic hemodialysis is directly dependent on their hemodialysis access. A brachiocephalic fistula (BCF) is commonly placed in the elderly and in patients with a failed lower-arm, or radiocephalic, fistula. However, there are numerous complications such that the BCF has an average patency of only 3.6 years. A leading cause of BCF dysfunction and failure is stenosis in the arch of the cephalic vein near its junction with the axillary vein, which is called cephalic arch stenosis (CAS). Using a combined clinical and computational investigation, we seek to improve our understanding of the cause of CAS, and to develop a means of predicting CAS risk in patients with a planned BCF access. This paper details the methodology used to determine the hemodynamic consequences of the post-fistula environment and illustrates detailed results for a representative sample of patient-specific anatomies, including a single, bifurcated, and trifurcated arch. It is found that the high flows present due to fistula creation lead to secondary flows in the arch owing to its curvature with corresponding low wall shear stresses. The abnormally low wall shear stress locations correlate with the development of stenosis in the singular case that is tracked in time for a period of one year. PMID:24695337

  20. 3. West end. Note arched basement entrance at north half ...

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

    3. West end. Note arched basement entrance at north half of west endwall. Sand tower (MN-99-E) at right. View to east. - Duluth & Iron Range Rail Road Company Shops, Oil House, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  1. 31. Interior detail view of arched, steelframed, stained glass windows ...

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

    31. Interior detail view of arched, steel-framed, stained glass windows at the landing of the south stairs in main lobby, view looking south from second floor lobby - University of Oregon Museum of Art, 1470 Johnson Lane, Eugene, Lane County, OR

  2. Detail of northern pier, pilaster, spring line, open spandrel arches, ...

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

    Detail of northern pier, pilaster, spring line, open spandrel arches, and spandrel colmns, facing northwest. Note the simple relief on the pilaster, indicative of the stripped classicism style. - Oakland Avenue Viaduct, Oakland Avenue spanning U.S. Route 62 (State Route 2302) & Pine Run, Sharon, Mercer County, PA

  3. 12. DETAIL VIEW OF BUTTRESS 8 AND HALF OF ARCH ...

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

    12. DETAIL VIEW OF BUTTRESS 8 AND HALF OF ARCH 7. THE IMPRESSIONS OF THE WOODEN FORMS ARE VISIBLE ON THE CONCRETE. ALSO VISIBLE IS THE PLACEMENT OF THE DAM DIRECTLY ON BEDROCK. - Hume Lake Dam, Sequioa National Forest, Hume, Fresno County, CA

  4. Arch Venture Partners' investment considerations for CBRNE products and opportunities

    NASA Astrophysics Data System (ADS)

    Crandell, K.; Lazarus, S.; Gardner, P. J.

    2008-04-01

    ARCH is interested in building leading, highly-valued companies from leading research. Toward that end we value innovations created by the leading researchers in the world, many of which are funded to solve critical scientific challenges including those in the instrumentation and CBRNE area. The most important CBRNE innovations we have seen at ARCH are breakthroughs involving significant unaddressed technology risk and have the potential for broad proprietary intellectual property as a result. The model ARCH has evolved in instrumentation is to look for a breakthrough innovation, with strong intellectual property and continue to strengthen the patent estate through the life of the company. ARCH looks to build companies around leading interdisciplinary scientific and engineering teams, and we favor platform technology that can be applied to multiple market applications both commercial and government. As part of a strategy to build a great company, addressing important CBRNE challenges can help a company strengthen its technical team and its IP estate. This supports a focus on early low volume markets on the way toward addressing a fuller portfolio of applications. Experienced Venture Capitalists can help this process by identifying important executive talent, partners and applications, offering financial syndication strength, and helping shape the company's strategy to maximize the ultimate value realized.

  5. 3D Stretchable Arch Ribbon Array Fabricated via Grayscale Lithography

    NASA Astrophysics Data System (ADS)

    Pang, Yu; Shu, Yi; Shavezipur, Mohammad; Wang, Xuefeng; Mohammad, Mohammad Ali; Yang, Yi; Zhao, Haiming; Deng, Ningqin; Maboudian, Roya; Ren, Tian-Ling

    2016-06-01

    Microstructures with flexible and stretchable properties display tremendous potential applications including integrated systems, wearable devices and bio-sensor electronics. Hence, it is essential to develop an effective method for fabricating curvilinear and flexural microstructures. Despite significant advances in 2D stretchable inorganic structures, large scale fabrication of unique 3D microstructures at a low cost remains challenging. Here, we demonstrate that the 3D microstructures can be achieved by grayscale lithography to produce a curved photoresist (PR) template, where the PR acts as sacrificial layer to form wavelike arched structures. Using plasma-enhanced chemical vapor deposition (PECVD) process at low temperature, the curved PR topography can be transferred to the silicon dioxide layer. Subsequently, plasma etching can be used to fabricate the arched stripe arrays. The wavelike silicon dioxide arch microstructure exhibits Young modulus and fracture strength of 52 GPa and 300 MPa, respectively. The model of stress distribution inside the microstructure was also established, which compares well with the experimental results. This approach of fabricating a wavelike arch structure may become a promising route to produce a variety of stretchable sensors, actuators and circuits, thus providing unique opportunities for emerging classes of robust 3D integrated systems.

  6. 3D Stretchable Arch Ribbon Array Fabricated via Grayscale Lithography.

    PubMed

    Pang, Yu; Shu, Yi; Shavezipur, Mohammad; Wang, Xuefeng; Mohammad, Mohammad Ali; Yang, Yi; Zhao, Haiming; Deng, Ningqin; Maboudian, Roya; Ren, Tian-Ling

    2016-01-01

    Microstructures with flexible and stretchable properties display tremendous potential applications including integrated systems, wearable devices and bio-sensor electronics. Hence, it is essential to develop an effective method for fabricating curvilinear and flexural microstructures. Despite significant advances in 2D stretchable inorganic structures, large scale fabrication of unique 3D microstructures at a low cost remains challenging. Here, we demonstrate that the 3D microstructures can be achieved by grayscale lithography to produce a curved photoresist (PR) template, where the PR acts as sacrificial layer to form wavelike arched structures. Using plasma-enhanced chemical vapor deposition (PECVD) process at low temperature, the curved PR topography can be transferred to the silicon dioxide layer. Subsequently, plasma etching can be used to fabricate the arched stripe arrays. The wavelike silicon dioxide arch microstructure exhibits Young modulus and fracture strength of 52 GPa and 300 MPa, respectively. The model of stress distribution inside the microstructure was also established, which compares well with the experimental results. This approach of fabricating a wavelike arch structure may become a promising route to produce a variety of stretchable sensors, actuators and circuits, thus providing unique opportunities for emerging classes of robust 3D integrated systems. PMID:27345766

  7. 11. Historic American Buildings Survey DETAIL OF SANCTUARY ARCH ...

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

    11. Historic American Buildings Survey DETAIL OF SANCTUARY ARCH - ST. PATRICK'S R. C. CHURCH c. 1839 - JAMES GALLIER, ARCHITECT, IN COLLECTION OF THE LOUISIANA STATE MUSEUM, JACKSON SQUARE, NEW ORLEANS, LA. - St. Patrick's Roman Catholic Church, 724 Camp Street, New Orleans, Orleans Parish, LA

  8. Bare Metal Stenting for Endovascular Exclusion of Aortic Arch Thrombi

    SciTech Connect

    Mahnken, Andreas H.; Hoffman, Andras; Autschbach, Ruediger; Damberg, Anneke L. M.

    2013-08-01

    BackgroundAortic thrombi in the ascending aorta or aortic arch are rare but are associated with a relevant risk of major stroke or distal embolization. Although stent grafting is commonly used as a treatment option in the descending aorta, only a few case reports discuss stenting of the aortic arch for the treatment of a thrombus. The use of bare metal stents in this setting has not yet been described.MethodsWe report two cases of ascending and aortic arch thrombus that were treated by covering the thrombus with an uncovered stent. Both procedures were performed under local anesthesia via a femoral approach. A femoral cutdown was used in one case, and a total percutaneous insertion was possible in the second case.ResultsBoth procedures were successfully performed without any periprocedural complications. Postoperative recovery was uneventful. In both cases, no late complications or recurrent embolization occurred at midterm follow-up, and control CT angiography at 1 respectively 10 months revealed no stent migration, freely perfused supra-aortic branches, and no thrombus recurrence.ConclusionTreating symptomatic thrombi in the ascending aorta or aortic arch with a bare metal stent is feasible. This technique could constitute a minimally invasive alternative to a surgical intervention or complex endovascular therapy with fenestrated or branched stent grafts.

  9. 10. View looking S at large arched opening that led ...

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

    10. View looking S at large arched opening that led from area where Jamaican Train was fired to steam engine and cane mill. - Hacienda Azucarera La Esperanza, Mill (Ruins), 2.65 miles North of PR Route 2 Bridge Over Manati River, Manati, Manati Municipio, PR

  10. Hemodynamics in the cephalic arch of a brachiocephalic fistula.

    PubMed

    Boghosian, M; Cassel, K; Hammes, M; Funaki, B; Kim, S; Qian, X; Wang, X; Dhar, P; Hines, J

    2014-07-01

    The care and outcome of patients with end stage renal disease (ESRD) on chronic hemodialysis is directly dependent on their hemodialysis access. A brachiocephalic fistula (BCF) is commonly placed in the elderly and in patients with a failed lower-arm, or radiocephalic, fistula. However, there are numerous complications such that the BCF has an average patency of only 3.6 years. A leading cause of BCF dysfunction and failure is stenosis in the arch of the cephalic vein near its junction with the axillary vein, which is called cephalic arch stenosis (CAS). Using a combined clinical and computational investigation, we seek to improve our understanding of the cause of CAS, and to develop a means of predicting CAS risk in patients with a planned BCF access. This paper details the methodology used to determine the hemodynamic consequences of the post-fistula environment and illustrates detailed results for a representative sample of patient-specific anatomies, including a single, bifurcated, and trifurcated arch. It is found that the high flows present due to fistula creation lead to secondary flows in the arch owing to its curvature with corresponding low wall shear stresses. The abnormally low wall shear stress locations correlate with the development of stenosis in the singular case that is tracked in time for a period of one year. PMID:24695337

  11. 7. DETAIL, LOOKING SOUTH, INTERIOR OF SOUTH ARCH, SHOWING DRAINAGE ...

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

    7. DETAIL, LOOKING SOUTH, INTERIOR OF SOUTH ARCH, SHOWING DRAINAGE HOLE IN THE WEST END OF THE SOUTH WALL AND VERTICAL QUARRY DRILLING HOLES ON THE STONE FACE - Mulladay Hollow Bridge, Spanning Mulladay Hollow Creek at County Road No.61, Eureka Springs, Carroll County, AR

  12. Detail view of the concrete arched balustrade railing and bushhammered ...

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

    Detail view of the concrete arched balustrade railing and bush-hammered inset posts - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

  13. 18. Upstream face of arches, concrete placing tower is at ...

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

    18. Upstream face of arches, concrete placing tower is at far right. Tower at center was used to convey material. Photographer unknown, January 29, 1927. Source: MWD. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  14. 23. 'General Drawing Of Proposed Three Hinged Arch Bridge At ...

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

    23. 'General Drawing Of Proposed Three Hinged Arch Bridge At Parks Bar Crossing Over The Yuba River, Yuba County Cal., Thomas System, Thomas & Post, Consulting Engrs, Hibernian Building, Los Angeles, Oct. 18, 1912,' and marked 'Revised Oct. 22, 1912.' - Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

  15. 22. 'General Drawing Of Proposed Three Hinged Arch Bridge At ...

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

    22. 'General Drawing Of Proposed Three Hinged Arch Bridge At Parks Bar Crossing Over The Yuba River, Yuba County Cal., Thomas System, Thomas & Post, Consulting Engrs, Hibernian Building, Los Angeles, Aug. 3, 1912.' - Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

  16. PERSPECTIVE VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, ...

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

    PERSPECTIVE VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, VIEW TO SOUTH OF SOUTHERN TRAVELING FORMWORK AND CABLE STAY TOWER. - Rex T. Barber Veterans Memorial Bridge, Spanning Crooked River Gorge, Dalles-California Highway (US 97), Terrebonne, Deschutes County, OR

  17. Detail of typical subdeck of granite pier showing humanscale arched ...

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

    Detail of typical subdeck of granite pier showing human-scale arched openings in pies. Note remnants of fender system. View north - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  18. Chemical Principles Revisited: Chemical Equilibrium.

    ERIC Educational Resources Information Center

    Mickey, Charles D.

    1980-01-01

    Describes: (1) Law of Mass Action; (2) equilibrium constant and ideal behavior; (3) general form of the equilibrium constant; (4) forward and reverse reactions; (5) factors influencing equilibrium; (6) Le Chatelier's principle; (7) effects of temperature, changing concentration, and pressure on equilibrium; and (8) catalysts and equilibrium. (JN)

  19. Three-dimensional stiffness of the carpal arch.

    PubMed

    Gabra, Joseph N; Li, Zong-Ming

    2016-01-01

    The carpal arch of the wrist is formed by irregularly shaped carpal bones interconnected by numerous ligaments, resulting in complex structural mechanics. The purpose of this study was to determine the three-dimensional stiffness characteristics of the carpal arch using displacement perturbations. It was hypothesized that the carpal arch would exhibit an anisotropic stiffness behavior with principal directions that are oblique to the conventional anatomical axes. Eight (n=8) cadavers were used in this study. For each specimen, the hamate was fixed to a custom stationary apparatus. An instrumented robot arm applied three-dimensional displacement perturbations to the ridge of trapezium and corresponding reaction forces were collected. The displacement-force data were used to determine a three-dimensional stiffness matrix using least squares fitting. Eigendecomposition of the stiffness matrix was used to identify the magnitudes and directions of the principal stiffness components. The carpal arch structure exhibited anisotropic stiffness behaviors with a maximum principal stiffness of 16.4±4.6N/mm that was significantly larger than the other principal components of 3.1±0.9 and 2.6±0.5N/mm (p<0.001). The principal direction of the maximum stiffness was pronated within the cross section of the carpal tunnel which is accounted for by the stiff transverse ligaments that tightly bind distal carpal arch. The minimal principal stiffness is attributed to the less constraining articulation between the trapezium and scaphoid. This study provides advanced characterization of the wrist׳s three-dimensional structural stiffness for improved insight into wrist biomechanics, stability, and function. PMID:26617368

  20. Low Density Lipoprotein transport in the normal human aortic arch

    PubMed Central

    Soulis, JV; Dimitrakopoulou, M; Giannoglou, GD

    2014-01-01

    Background: To understand the genesis and progression of atherosclerosis is essential to elucidate the blood flow and the transport of molecules in the cardiovascular system. The purpose of this computational study is to elucidate the relationship between low wall shear stress (WSS) - high site concentration of low density lipoproteins (LDL) and atherosclerotic sites in the normal human aortic arch under physiological flow and mass transport conditions. Methods: The numerical simulation couples the flow equations with the transport equation applying realistic boundary conditions at the wall in terms of blood-side concentration. The blood is considered to be non-Newtonian fluid obeying to the power law. Suitable mass transport conditions are specified at the wall. Results: Aortic arch walls are exposed to cholesterolemic environment although the applied mass and flow conditions refer to normal human geometry and normal mass-flow conditions. The luminal surface LDL concentration varies inversely with the WSS. Regions of high LDL luminal surface concentration do not necessarily co-locate to the sites of lowest WSS. Concave sides of the aortic arch exhibit, relatively to the convex sides, elevated concentration of the LDL. The area averaged normalized LDL concentration over the entire normal aortic arch is 1.267. The daughter aortic arch vessels exhibit, relatively to the main aorta, elevated LDL concentrations. Conclusions: The near wall paths of the velocities might be the most important factor for the elevated LDL concentration at areas located either at the vicinity of bifurcations regions or at high curvature regions. Hippokratia 2014; 18 (3): 221-225. PMID:25694755

  1. Computing Equilibrium Chemical Compositions

    NASA Technical Reports Server (NTRS)

    Mcbride, Bonnie J.; Gordon, Sanford

    1995-01-01

    Chemical Equilibrium With Transport Properties, 1993 (CET93) computer program provides data on chemical-equilibrium compositions. Aids calculation of thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93/PC is version of CET93 specifically designed to run within 640K memory limit of MS-DOS operating system. CET93/PC written in FORTRAN.

  2. Lucy's Flat Feet: The Relationship between the Ankle and Rearfoot Arching in Early Hominins

    PubMed Central

    2010-01-01

    Background In the Plio-Pleistocene, the hominin foot evolved from a grasping appendage to a stiff, propulsive lever. Central to this transition was the development of the longitudinal arch, a structure that helps store elastic energy and stiffen the foot during bipedal locomotion. Direct evidence for arch evolution, however, has been somewhat elusive given the failure of soft-tissue to fossilize. Paleoanthropologists have relied on footprints and bony correlates of arch development, though little consensus has emerged as to when the arch evolved. Methodology/Principal Findings Here, we present evidence from radiographs of modern humans (n = 261) that the set of the distal tibia in the sagittal plane, henceforth referred to as the tibial arch angle, is related to rearfoot arching. Non-human primates have a posteriorly directed tibial arch angle, while most humans have an anteriorly directed tibial arch angle. Those humans with a posteriorly directed tibial arch angle (8%) have significantly lower talocalcaneal and talar declination angles, both measures of an asymptomatic flatfoot. Application of these results to the hominin fossil record reveals that a well developed rearfoot arch had evolved in Australopithecus afarensis. However, as in humans today, Australopithecus populations exhibited individual variation in foot morphology and arch development, and “Lucy” (A.L. 288-1), a 3.18 Myr-old female Australopithecus, likely possessed asymptomatic flat feet. Additional distal tibiae from the Plio-Pleistocene show variation in tibial arch angles, including two early Homo tibiae that also have slightly posteriorly directed tibial arch angles. Conclusions/Significance This study finds that the rearfoot arch was present in the genus Australopithecus. However, the female Australopithecus afarensis “Lucy” has an ankle morphology consistent with non-pathological flat-footedness. This study suggests that, as in humans today, there was variation in arch development

  3. [Mycotic Aneurysm of Distal Aortic Arch, after Total Arch Replacement with Open-stent Graft;Report of a Case].

    PubMed

    Suzuki, Kotaro; Kawahara, Yu; Masaki, Naoki; Kobayashi, Yuriko; Takahara, Shingo; Nakamura, Ken; Toyama, Shuji; Fukasawa, Manabu

    2015-05-01

    The patient was a 72-year-old man, who had undergone total arch replacement with an open-stent graft due to saccular aneurysm of distal arch, 2 years before. He was admitted to a local hospital with the complaint of high fever, and was diagnosed as having pyothorax, after computed tomography (CT) scanning. After transferred to our hospital, he was treated by drainage, and antibiotic therapy. But CT scans showed the enlargement of distal arch aneurysm, and migration of the stent graft. Urgent operation was performed. We approached to the site by a full sternotomy, and left anterolateral thoracotomy. Segment 1+2 of the left lung was resected to avoid bleeding and lung injury. Graft replacement of distal arch and descending aorta was performed on cardiopulmonary bypass, with hypothermia, selective brain perfusion and systemic circulatory arrest. To protect from recurrence of infection, the omental flap was transposed to the graft site. Until now, there is no recurrence of infection. PMID:25963790

  4. Sun's procedure for complex aortic arch repair: total arch replacement using a tetrafurcate graft with stented elephant trunk implantation.

    PubMed

    Ma, Wei-Guo; Zhu, Jun-Ming; Zheng, Jun; Liu, Yong-Min; Ziganshin, Bulat A; Elefteriades, John A; Sun, Li-Zhong

    2013-09-01

    The Sun's procedure is a surgical technique proposed by Dr. Li-Zhong Sun in 2002 that integrates total aortic arch replacement using a tetrafurcated graft with implantation of a specially designed frozen elephant trunk (Cronus(®)) in the descending aorta. It is used as a treatment option for extensive aortic dissections or aneurysms involving the ascending aorta, aortic arch and the descending aorta. The technical essentials of Sun's procedure include implantation of the special open stented graft into the descending aorta, total arch replacement with a 4-branched vascular graft, right axillary artery cannulation, selective antegrade cerebral perfusion for brain protection, moderate hypothermic circulatory arrest at 25 °C, a special anastomotic sequence for aortic reconstruction (i.e., proximal descending aorta → left carotid artery → ascending aorta → left subclavian artery → innominate artery), and early rewarming and reperfusion after distal anastomosis to minimize cerebral and cardiac ischemia. The core advantage of Sun's procedure lies in the use of a unique stented graft, which has superior technical simplicity, flexibility, inherent mechanical durability and an extra centimeter of attached regular vascular graft at both ends. Since its introduction in 2003, the Sun's procedure has produced satisfactory early and long-term results in over 8,000 patients in China and more than 200 patients in South American countries. In a series of 1,092 patients, the authors have achieved an in-hospital mortality rate of 6.27% (7.98% in emergent or urgent vs. 3.98% in elective cases). Given the accumulating clinical experience and the consequent, continual evolution of surgical indications, the Sun's procedure is becoming increasingly applied/used worldwide as an innovative and imaginative enhancement of surgical options for the dissected (or aneurysmal) ascending aorta, aortic arch and proximal descending aorta, and may become the next standard treatment for type

  5. Equilibrium games in networks

    NASA Astrophysics Data System (ADS)

    Li, Angsheng; Zhang, Xiaohui; Pan, Yicheng; Peng, Pan

    2014-12-01

    It seems a universal phenomenon of networks that the attacks on a small number of nodes by an adversary player Alice may generate a global cascading failure of the networks. It has been shown (Li et al., 2013) that classic scale-free networks (Barabási and Albert, 1999, Barabási, 2009) are insecure against attacks of as small as O(logn) many nodes. This poses a natural and fundamental question: Can we introduce a second player Bob to prevent Alice from global cascading failure of the networks? We proposed a game in networks. We say that a network has an equilibrium game if the second player Bob has a strategy to balance the cascading influence of attacks by the adversary player Alice. It was shown that networks of the preferential attachment model (Barabási and Albert, 1999) fail to have equilibrium games, that random graphs of the Erdös-Rényi model (Erdös and Rényi, 1959, Erdös and Rényi, 1960) have, for which randomness is the mechanism, and that homophyly networks (Li et al., 2013) have equilibrium games, for which homophyly and preferential attachment are the underlying mechanisms. We found that some real networks have equilibrium games, but most real networks fail to have. We anticipate that our results lead to an interesting new direction of network theory, that is, equilibrium games in networks.

  6. Computational Study of Growth and Remodeling in the Aortic Arch

    PubMed Central

    Alford, Patrick W.; Taber, Larry A.

    2009-01-01

    Opening angles (OAs) are associated with growth and remodeling in arteries. One curiosity has been the relatively large OAs found in the aortic arch of some animals. Here, we use computational models to explore the reasons behind this phenomenon. The artery is assumed to contain a smooth muscle/collagen phase and an elastin phase. In the models, growth and remodeling of smooth muscle/collagen depends on wall stress and fluid shear stress. Remodeling of elastin, which normally turns over very slowly, is neglected. The results indicate that OAs generally increase with longitudinal curvature (torus model), earlier elastin production during development, and decreased wall stiffness. Correlating these results with available experimental data suggests that all of these effects may contribute to the large OAs in the aortic arch. The models also suggest that the slow turnover rate of elastin limits longitudinal growth. These results should promote increased understanding of the causes of residual stress in arteries. PMID:18792831

  7. Post Flare Giant Arches and Run-Away Reconnection

    NASA Astrophysics Data System (ADS)

    West, Matthew; Seaton, Daniel B.; Savage, Sabrina; Bryans, Paul

    2016-05-01

    The nature of post-flare giant arches and their relation to regular post flare loops has long been debated, especially in the context of how post-flare giant arches can sustain their growth for such long periods. In this presentation we discuss how magnetic reconnection can be sustained to such great heights, and the role the background corona plays in maintaining this growth. We use observations from 14 October 2014, when the SWAP EUV solar telescope on-board the PROBA2 spacecraft observed an eruption that led to the formation of perhaps the largest post-eruptive loop system seen in the solar corona in solar cycle 24. These loops grew to a height of approximately 400000 km (>0.5 solar-radii). We provide evidence of on-going reconnection, through observations spanning from the chromosphere to the middle corona, and discuss how only certain conditions can maintain prolonged growth.

  8. Controlled localized buckling responses of orthodontic arch wires.

    PubMed

    Nikolai, R J; Chung, A Y

    1999-09-01

    The orthodontic arch wire is often activated locally, in transverse bending and/or longitudinal torsion, to engage an individual malaligned tooth. Arch wires with substantial flexibilities and elastic ranges in bending are available. Several clinical reports of distal displacements of molars with appliances activated by locally buckling the arch wire have appeared in the recent published literature. This article contains an explanation of buckling or "column" action and the postbuckling response of a wire, and a report of the results of a controlled, in-vitro study of a sample of 256 wire segments subjected to activation-deactivation, buckling-postbuckling-unbuckling cycles. Continuous force-displacement diagrams were obtained from mechanical tests run at oral temperature. Four orthodontics-relevant, mechanical characteristics were quantified from each diagram, and each specimen was subjected to posttest evaluation for inelastic behavior. Although the deformation of the buckled wire is, in fact, bending, the force-displacement diagrams obtained differed substantially from their familiar counterparts generated in transverse bending. Judging from the force magnitudes induced as the deactivation half-cycles commenced as well as the deactivation rates, not all of the 8 wires seem to be clinically suitable for activation initiated by buckling. Magnitudes of springback were substantial from activations as large as 6 mm, and only 2 of the 8 wires exhibited full deactivations less than 80% of their activating displacements. This relatively new mode of arch wire activation that enables delivery to the dentition of mesiodistal pushing forces has substantial potential for clinical application from several biomechanical standpoints. PMID:10474103

  9. Left cervical aortic arch: diagnosis by radioisotope and ultrasound techniques

    SciTech Connect

    Camiel, M.R.; Glanz, S.; Gordon, D.H.; Weiner, R.

    1982-01-01

    Two case histories are presented of patients with a developmental variant of the heart. The condition is usually innocuous but its appearance is confusing and incorrect diagnoses are possible. Although the abnormality is usually first detected by routine chest X-ray, radionuclide angiography and sonography are more appropriate diagnostic measures. The two methods can differentiate between the cervical aortic arch and aneurysm or lung tumor. (JMT)

  10. Double arch mirror study. Part 3: Fabrication and test report

    NASA Technical Reports Server (NTRS)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    A method of mounting a cryogenically cooled, lightweight, double arch, glass mirror was developed for infrared, astronomical telescopes such as the Space Infrared Telescope Facility (SIRTF). A 50 cm, fused silica mirror which was previously fabricated was modified for use with a new mount configuration. This mount concept was developed. The modification of the mirror, the fabrication of the mirror mount, and the room temperature testing of the mounted mirror are reported. A design for a SIRTF class primary mirror is suggested.

  11. Disentangling the Free-Fall Arch Paradox in Silo Discharge.

    PubMed

    Rubio-Largo, S M; Janda, A; Maza, D; Zuriguel, I; Hidalgo, R C

    2015-06-12

    Several theoretical predictions of the mass flow rate of granular media discharged from a silo are based on the spontaneous development of a free-fall arch region, the existence of which is still controversial. In this Letter, we study experimentally and numerically the particle flow through an orifice placed at the bottom of 2D and 3D silos. The implementation of a coarse-grained technique allows a thorough description of all the kinetic and micromechanical properties of the particle flow in the outlet proximities. Though the free-fall arch does not exist as traditionally understood--a region above which particles have negligible velocity and below which particles fall solely under gravity action--we discover that the kinetic pressure displays a well-defined transition in a position that scales with the outlet size. This universal scaling explains why the free-fall arch picture has served as an approximation to describe the flow rate in the discharge of silos. PMID:26196830

  12. Relations between anterior permanent teeth, dental arches and hard palate.

    PubMed

    Petricević, Nikola; Stipetić, Jasmina; Antonić, Robert; Borcić, Josipa; Strujić, Mihovil; Kovacić, Ivan; Celebić, Asja

    2008-12-01

    The width and length of the anterior teeth, the dimensions of the frontal dental arches and the dimensions of the hard palate were measured (24 men and 56 women, age range of 18-30 years). The results showed gender-related dimorphism only for the cervical width of the maxillary canine, which were wider in men, p < 0.05. The width-to-length ratios of the maxillary frontal teeth varied from 0.82 to 0.91. The tooth-to-tooth width ratios among different maxillary frontal teeth varied from 0.78 to 0.91. The sum of all anterior maxillary teeth widths was equal to the hamular width and to the distal maxillary arch width (p > 0.05), meaning that the sum of the frontal artificial teeth width may be selected upon the measurement of the hamular width on the hard palate. The ratios between the maxillary and the mandibular frontal dental arch dimensions are representative values for the skeletal class I. PMID:19149214

  13. The Foot’s Arch and the Energetics of Human Locomotion

    PubMed Central

    Stearne, Sarah M.; McDonald, Kirsty A.; Alderson, Jacqueline A.; North, Ian; Oxnard, Charles E.; Rubenson, Jonas

    2016-01-01

    The energy-sparing spring theory of the foot’s arch has become central to interpretations of the foot’s mechanical function and evolution. Using a novel insole technique that restricted compression of the foot’s longitudinal arch, this study provides the first direct evidence that arch compression/recoil during locomotion contributes to lowering energy cost. Restricting arch compression near maximally (~80%) during moderate-speed (2.7 ms−1) level running increased metabolic cost by + 6.0% (p < 0.001, d = 0.67; unaffected by foot strike technique). A simple model shows that the metabolic energy saved by the arch is largely explained by the passive-elastic work it supplies that would otherwise be done by active muscle. Both experimental and model data confirm that it is the end-range of arch compression that dictates the energy-saving role of the arch. Restricting arch compression had no effect on the cost of walking or incline running (3°), commensurate with the smaller role of passive-elastic mechanics in these gaits. These findings substantiate the elastic energy-saving role of the longitudinal arch during running, and suggest that arch supports used in some footwear and orthotics may increase the cost of running. PMID:26783259

  14. Modified complete-arch impression technique for facilitating esthetic and biomechanical precision in complete-arch rehabilitation.

    PubMed

    Mizrahi, Basil

    2011-08-01

    Treating complex cases is clinically and technically challenging, yet highly rewarding to both patient and clinician when successfully completed. Precision in the fit of the restorations, the definitive occlusal scheme, and the esthetic result are the key elements to long-term success. Clinicians should aim to achieve the same level of precision when treating these cases as they do when treating simple cases; however, with the numerous stages and increased complexity involved comes the potential for errors to compound and magnify as treatment progresses. Areas particularly prone to difficulties are the making of a complete-arch impression and the ability to maintain patient comfort and eliminate unwanted dental emergencies throughout the time-consuming treatment. This report illustrates the techniques and concepts used to achieve esthetic and biomechanical precision when treating complex cases. Specific emphasis is placed on the importance of an accurate complete-arch impression technique, the detail of which is described in the article. PMID:21843229

  15. An Updated Equilibrium Machine

    ERIC Educational Resources Information Center

    Schultz, Emeric

    2008-01-01

    A device that can demonstrate equilibrium, kinetic, and thermodynamic concepts is described. The device consists of a leaf blower attached to a plastic container divided into two chambers by a barrier of variable size and form. Styrofoam balls can be exchanged across the barrier when the leaf blower is turned on and various air pressures are…

  16. ARCHES: Advancing Research & Capacity in Hydrologic Education and Science

    NASA Astrophysics Data System (ADS)

    Milewski, A.; Fryar, A. E.; Durham, M. C.; Schroeder, P.; Agouridis, C.; Hanley, C.; Rotz, R. R.

    2013-12-01

    Educating young scientists and building capacity on a global scale is pivotal towards better understanding and managing our water resources. Based on this premise the ARCHES (Advancing Research & Capacity in Hydrologic Education and Science) program has been established. This abstract provides an overview of the program, links to access information, and describes the activities and outcomes of student participants from the Middle East and North Africa. The ARCHES program (http://arches.wrrs.uga.edu) is an integrated hydrologic education approach using online courses, field programs, and various hands-on workshops. The program aims to enable young scientists to effectively perform the high level research that will ultimately improve quality of life, enhance science-based decision making, and facilitate collaboration. Three broad, interlinked sets of activities are incorporated into the ARCHES program: (A1) the development of technical expertise, (A2) the development of professional contacts and skills, and (A3) outreach and long-term sustainability. The development of technical expertise (A1) is implemented through three progressive instructional sections. Section 1: Students were guided through a series of online lectures and exercises (Moodle: http://wrrs.uga.edu/moodle) covering three main topics (Remote Sensing, GIS, and Hydrologic Modeling). Section 2: Students participated in a hands-on workshop hosted at the University of Georgia's Water Resources and Remote Sensing Laboratory (WRRSL). Using ENVI, ArcGIS, and ArcSWAT, students completed a series of lectures and real-world applications (e.g., Development of Hydrologic Models). Section 3: Students participated in field studies (e.g., measurements of infiltration, recharge, streamflow, and water-quality parameters) conducted by U.S. partners and international collaborators in the participating countries. The development of professional contacts and skills (A2) was achieved through the promotion of networking

  17. Dermatoglyphic assessment in subjects with different dental arch forms: an appraisal.

    PubMed

    Sachdeva, Shabina; Tripathi, Arvind; Kapoor, Pranav

    2014-09-01

    Successful rehabilitation of edentulous individuals involves selection and arrangement of artificial teeth in accordance with the patient's original arch form. Various criteria exist for harmonious tooth arrangement but none is accepted universally. Finger and palm prints are unique to an individual and once formed in the sixth week of intra-uterine life, remain constant thereafter. Since dental arches are also formed during the same prenatal period, it is believed that the similar genetic factors may be involved in formation of dental arches and dermal patterns. This study was conducted to identify the association if any between type of dental arch forms and type of dermatoglyphic patterns. If specific dermal characteristics exist in individuals with specific dental arch forms, dermatoglyphic assessment of long standing edentulous subjects may help identify the patients preexisting dental arch form and thus aid in proper tooth arrangement. Ninety dentulous subjects were categorized into three groups on the basis of dental arch form (square, tapering or ovoid) and their finger and palm prints were recorded. The type of fingertip patterns, distribution of palmar patterns, Total Finger Ridge Count and angle atd were assessed. Subjects with square arches demonstrated a significantly high frequency of loops and a large atd angle with palmar patterns being most frequent in I3 region. Subjects with tapering arches showed a high frequency of whorls, a small atd angle and greatest distribution of palmar patterns in I4 region. In ovoid arched subjects, loops were the most common and palmar patterns were mostly observed in I4. Since distinctive dermal patterns were observed in subjects with different dental arch forms, it is believed that dermatoglyphics may be used as a reliable tool for identifying original arch form in edentulous patients. PMID:25183912

  18. 13. Photocopy of a photographca. 1896showing wooden arch bridge over ...

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

    13. Photocopy of a photograph--ca. 1896--showing wooden arch bridge over the North Fork of the San Joaquin River northeast of Fresno, CA. This structure was designed by Eastwood as part of the San Joaquin Electric Company's hydro-electric plant; it is a design that indicates his interest in the structural capabilities of the arch before he began building multiple arch dams. Courtesy Mr. Charles Allan Whitney. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  19. An Updated Equilibrium Machine

    NASA Astrophysics Data System (ADS)

    Schultz, Emeric

    2008-08-01

    A device that can demonstrate equilibrium, kinetic, and thermodynamic concepts is described. The device consists of a leaf blower attached to a plastic container divided into two chambers by a barrier of variable size and form. Styrofoam balls can be exchanged across the barrier when the leaf blower is turned on and various air pressures are applied. Equilibrium can be approached from different distributions of balls in the container under different conditions. The Le Châtelier principle can be demonstrated. Kinetic concepts can be demonstrated by changing the nature of the barrier, either changing the height or by having various sized holes in the barrier. Thermodynamic concepts can be demonstrated by taping over some or all of the openings and restricting air flow into container on either side of the barrier.

  20. Absolute Equilibrium Entropy

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1997-01-01

    The entropy associated with absolute equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.

  1. The equilibrium dayside magnetosphere

    NASA Technical Reports Server (NTRS)

    Zavriyev, Anton; Hasegawa, Akira

    1989-01-01

    A method is presented of computing the dayside global earth magnetic field which is in equilibrium with the plasma pressure, based on satellite observations at a local region of the magnetosphere. The method, which utilizes a perturbation around a dipole magnetic field, involves computation of the global plasma pressure profile based on the equatorial (anisotropic) pressure data, derivation of the current profile which satisfies the equilibrium condition, and computation of the magnetic field using the current profile and the boundary current produced by the solar wind. The method is applied for the Active Magnetospheric Particle Tracer Explorers data, and the result of the computation is found to compare reasonably well with the observed magnetic field profile near the geomagnetic equator.

  2. [The form of the dental arch according to the Tweed-Merrifield philosophy: individualization and attempt at standardization].

    PubMed

    Amm, E W; Bou-Serhal, J P

    2003-12-01

    A literature review reveals that changes from the initial arch form lead to a proportionate amount of subsequent relapse and that there is great variation among human arch forms. A persistent search for the ideal arch form is still going on. Many authors presented different techniques for its individualization. A new software ("Arch form generator") was developed to create the arch form following the Tweed-Merrifield concepts. The form and dimensions of 169 mandibular arches were evaluated along with Angle classification and facial type as variables. The reliability of the Ricketts pentamorphic arch forms was questioned and a new arch guide was developed as part of a trial for standardization. The Class III cases showed greater width and smaller cuspid depth when compared to the Class I and Class II cases. The hypodivergent cases showed greater width when compared to the hyperdivergent and normodivergent cases. There is no characteristic form for the human dental arch. PMID:15301362

  3. Solids Far from Equilibrium

    NASA Astrophysics Data System (ADS)

    Godrèche, C.

    2011-03-01

    Preface; 1. Shape and growth of crystals P. Nozières; 2. Instabilities of planar solidification fronts B. Caroli, C. Caroli and B. Roulet; 3. An introduction to the kinetics of first-order phase transition J. S. Langer; 4. Dendritic growth and related topics Y. Pomeau and M. Ben Amar; 5. Growth and aggregation far from equilibrium L. M. Sander; 6. Kinetic roughening of growing surfaces J. Krug and H. Spohn; Acknowledgements; References; Index.

  4. Exoplanet Equilibrium Chemistry Calculations

    NASA Astrophysics Data System (ADS)

    Blumenthal, Sarah; Harrington, J.; Bowman, M.; Blecic, J.

    2013-10-01

    Recently, Agundez et al. (2012, A&A 548, A73) used a chemical kinetics code to study a model HD 209458b (equilibrium temperature of 1450 K, assuming full redistribution and 0 albedo). They found that thermochemistry dominates most of the dayside, but that significant compositional gradients may exist across the dayside. We calculate equilibrium-chemistry molecular abundances for several model exoplanets, using NASA's open-source Chemical Equilibrium Abundances code (McBride and Gordon 1996). We vary the degree of radiation redistribution to the dark side, ranging from total redistribution to instantaneous reradiation. Atomically, both the solar abundance multiple and the carbon fraction vary. Planet substellar temperatures range from just above 1200 K, where photochemistry should no longer be important, to those of hot planets (3000 K). We present synthetic abundance images for the key spectroscopic molecules CO, CH4, and H2O for several hot-Jupiter model planets. This work was supported by the NASA Planetary Atmospheres grant NNX12AI69G.

  5. Equilibrium Electroconvective Instability

    NASA Astrophysics Data System (ADS)

    Rubinstein, I.; Zaltzman, B.

    2015-03-01

    Since its prediction 15 years ago, hydrodynamic instability in concentration polarization at a charge-selective interface has been attributed to nonequilibrium electro-osmosis related to the extended space charge which develops at the limiting current. This attribution had a double basis. On the one hand, it has been recognized that neither equilibrium electro-osmosis nor bulk electroconvection can yield instability for a perfectly charge-selective solid. On the other hand, it has been shown that nonequilibrium electro-osmosis can. The first theoretical studies in which electro-osmotic instability was predicted and analyzed employed the assumption of perfect charge selectivity for the sake of simplicity and so did the subsequent studies of various time-dependent and nonlinear features of electro-osmotic instability. In this Letter, we show that relaxing the assumption of perfect charge selectivity (tantamount to fixing the electrochemical potential of counterions in the solid) allows for the equilibrium electroconvective instability. In addition, we suggest a simple experimental test for determining the true, either equilibrium or nonequilibrium, origin of instability in concentration polarization.

  6. Ball motion and sliding friction in an arched outer-race ball bearing

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.

    1974-01-01

    The motion of the ball and sliding friction in an arched outer-race ball bearing under thrust load is analyzed. Fatigue life evaluations were made. The analysis is applied to a 150-millimeter-bore ball bearing. The results indicated that for high-speed light-load applications the arched bearing has significant improvement in fatigue life over that of a conventional bearing. An arching of 0.254 mm (0.01 in.) was found to be optimal. Also, for an arched bearing a considerable amount of spinning occurs at the outer-race contacts.

  7. Ball motion and sliding friction in an arched outer race ball bearing

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.

    1973-01-01

    The motion of the ball and sliding friction in an arched outer race ball bearing under thrust loads is determined. Fatigue life evaluations were made. The analysis is applied to a 150 millimeter bore ball bearing. The results indicated that for high speed-light load applications the arched bearing has significant improvement in fatigue life over that of a conventional bearing. An arching of 0.254 mm (0.01 in.) was found to be an optimal. For an arched bearing it was also found that a considerable amount of spinning occurs at the outer race contacts.

  8. KD loop for increasing arch perimeter in cleft and noncleft cases.

    PubMed

    Dholakia, Kartik D; Bhat, Shweta R

    2012-01-01

    One of the many indications for dental arch expansion in treating malocclusion is to achieve arch compatibility, especially in surgical cases with severe Bolton discrepancies or collapsed arches due to congenitally missing anterior teeth. These cases usually require expansion in both the sagittal and transverse plane to achieve normal arch compatibility. Arch compatibility can be achieved by either dentoalveolar or skeletal expansion or both. Orthodontically, dentoalveolar expansion can be achieved by means of expanded arch form, vertical loops, or an added assembly such as a quad helix or Ni-Ti expander from the palatal or lingual aspect of the arch. However, these modalities normally provide expansion along transverse plane. If any expansion along sagittal plane is required, then additional appliances such as TransForce or modifications in the appliance system (eg, a quad helix with extension on anterior teeth) are necessary. Vertical loops do overcome these drawbacks to a certain extent; however, at the expense of generating moments during preactivation, which may lead to tipping of segments adjacent to the loop and precludes its use for larger changes of arch dimension. This article describes a new loop design--the KD loop--that increases the arch perimeter by sagittal and transverse expansion without generating significant moments along vertical plane. PMID:22567644

  9. Ball motion and sliding friction in an arched outer race ball bearing

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.

    1974-01-01

    The motion of the ball and sliding friction in an arched outer-race ball bearing under thrust load is determined. Fatigue life evaluations were made. The analysis is applied to a 150 millimeter bore ball bearing. The results indicated that for high speed-light load applications the arched bearing has significant improvement in fatigue life over that of a conventional bearing. An arching of 0.254 mm (0.01 in.) was found to be an optimal. For an arched bearing it was also found that a considerable amount of spinning occurs at the outer race contacts.

  10. Syndromes of the first and second pharyngeal arches: A review.

    PubMed

    Passos-Bueno, Maria Rita; Ornelas, Camila C; Fanganiello, Roberto D

    2009-08-01

    Our aim in this review is to discuss currently known mechanisms associated with three important syndromes of the first and second pharyngeal arches: Treacher Collins syndrome (TCS), Oculo-auriculo-vertebral syndrome (AOVS) and Auriculo-Condylar syndrome (ACS) or question mark ear syndrome. TCS and ACS are autosomal dominant diseases, with nearly complete penetrance and wide spectrum of clinical variability. The phenotype of the latter has several overlapping features with OAVS, but OAVS may exist in both sporadic and autosomal dominant forms. Mutations in the TCOF1 gene are predicted to cause premature termination codons, leading to haploinsuficiency of the protein treacle and causing TCS. Low amount of treacle leads ultimately to a reduction in the number of cranial neural crest cells migrating to the first and second pharyngeal arches. Other than TCS, the genes associated with ACS and OAVS are still unknown. The first locus for ACS was mapped by our group to 1p21-23 but there is genetic heretogeneity. Genetic heterogeneity is also present in OAVS. Based on the molecular analysis of balanced translocation in an OAVS patient, it has been suggested that abnormal expression of BAPX1 possibly due to epigenetic disregulation might be involved with the etiology of OAVS. Involvement of environmental events has also been linked to the causation of OAVS. Identification of factors leading to these disorders are important for a comprehensive delineation of the molecular pathways underlying the craniofacial development from the first and the second pharyngeal arches, for genetic counseling and to open alternative strategies for patient treatment. PMID:19610085

  11. Impending rupture in an aortic arch aneurysm by Candida infection.

    PubMed

    Minami, H; Wakita, N; Kawanishi, Y; Kitano, I; Sakata, M

    2001-03-01

    A 68-year-old man was hospitalized with the complaints of left back pain and fever. He had a history of using steroids to treat uveitis for about thirty years. Computed tomography on the chest demonstrated an impending rupture in an aortic arch aneurysm, which was consequently surgically excised. Candida albicans was identified in the wall of the aneurysm, so fluconazole and itraconazole were administered. The patient was discharged at 120 days after surgery without recrudescence of the candida. To our knowledge, this is the fifteenth case of a successfully treated aneurysm caused by candida infection. PMID:11305059

  12. Excitation of the arched filaments near the Galactic Center

    NASA Technical Reports Server (NTRS)

    Colgan, Sean W. J.; Erickson, Edwin F.; Simpson, Janet P.; Haas, Michael R.; Morris, Mark

    1995-01-01

    We discuss measurements of the far-infrared (FIR) fine structure lines from (S III) (33 microns), (Si II) (35 microns), (O III) (51, 88 microns), (OI) (63 microns), (C II) (158 microns), and the adjacent continua in a strip crossing two of the thermal radio filaments in the Galactic Center 'Arch'. The near spatial coincidence of the line and continuum emission maxima with the radio filaments demonstrates that any excitation mechanism must account for both the line and continuum emission. The peak FIR luminosity and (O III) emission pose difficulties for collisional excitation models; photoionization of molecular cloud edges by a random distribution of stars is the most plausible mechanism proposed.

  13. Structural design using equilibrium programming

    NASA Technical Reports Server (NTRS)

    Scotti, Stephen J.

    1992-01-01

    Multiple nonlinear programming methods are combined in the method of equilibrium programming. Equilibrium programming theory has been appied to problems in operations research, and in the present study it is investigated as a framework to solve structural design problems. Several existing formal methods for structural optimization are shown to actually be equilibrium programming methods. Additionally, the equilibrium programming framework is utilized to develop a new structural design method. Selected computational results are presented to demonstrate the methods.

  14. Narrowing carpal arch width to increase cross-sectional area of carpal tunnel – a cadaveric study

    PubMed Central

    Li, Zong-Ming; Gabra, Joseph N.; Marquardt, Tamara L.; Kim, Dong Hee

    2013-01-01

    Background Carpal tunnel morphology plays an essential role in the etiology and treatment of carpal tunnel syndrome. The purpose of this study was to observe the morphological changes of the carpal tunnel as a result of carpal arch width narrowing. It was hypothesized carpal arch width narrowing would result in increased height and area of the carpal arch. Methods The carpal arch width of eight cadaveric hands was narrowed by a custom apparatus and cross-sectional ultrasound images were acquired. The carpal arch height and area were quantified as the carpal arch width was narrowed. Correlation and regression analyses were performed for the carpal arch height and area with respect to the carpal arch width. Findings The carpal tunnel became more convex as the carpal arch width was narrowed. The initial carpal arch width, height, and area were 25.7 (SD 1.9) mm, 4.1 (SD 0.6) mm, and 68.5 (SD 14.0) mm2, respectively. The carpal arch height and area negatively correlated with the carpal arch width, with correlation coefficients of −0.974 (SD 0.018) and −0.925 (SD 0.034), respectively. Linear regression analyses showed a 1 mm narrowing of the carpal arch width resulted in proportional increases of 0.40 (SD 0.14) mm in the carpal arch height and 4.0 (SD 2.2) mm2 in the carpal arch area. Interpretation This study demonstrates that carpal arch width narrowing leads to increased carpal arch height and area, a potential mechanism to reduce the mechanical insult to the median nerve and relieve symptoms associated with carpal tunnel syndrome. PMID:23583095

  15. Building problem solving environments with the arches framework

    SciTech Connect

    Debardeleben, Nathan; Sass, Ron; Stanzione, Jr., Daniel; Ligon, Ill, Walter

    2009-01-01

    The computational problems that scientists face are rapidly escalating in size and scope. Moreover, the computer systems used to solve these problems are becoming significantly more complex than the familiar, well-understood sequential model on their desktops. While it is possible to re-train scientists to use emerging high-performance computing (HPC) models, it is much more effective to provide them with a higher-level programming environment that has been specialized to their particular domain. By fostering interaction between HPC specialists and the domain scientists, problem-solving environments (PSEs) provide a collaborative environment. A PSE environment allows scientists to focus on expressing their computational problem while the PSE and associated tools support mapping that domain-specific problem to a high-performance computing system. This article describes Arches, an object-oriented framework for building domain-specific PSEs. The framework was designed to support a wide range of problem domains and to be extensible to support very different high-performance computing targets. To demonstrate this flexibility, two PSEs have been developed from the Arches framework to solve problem in two different domains and target very different computing platforms. The Coven PSE supports parallel applications that require large-scale parallelism found in cost-effective Beowulf clusters. In contrast, RCADE targets FPGA-based reconfigurable computing and was originally designed to aid NASA Earth scientists studying satellite instrument data.

  16. archAR: an archaeological augmented reality experience

    NASA Astrophysics Data System (ADS)

    Wiley, Bridgette; Schulze, Jürgen P.

    2015-03-01

    We present an application for Android phones or tablets called "archAR" that uses augmented reality as an alternative, portable way of viewing archaeological information from UCSD's Levantine Archaeology Laboratory. archAR provides a unique experience of flying through an archaeological dig site in the Levantine area and exploring the artifacts uncovered there. Using a Google Nexus tablet and Qualcomm's Vuforia API, we use an image target as a map and overlay a three-dimensional model of the dig site onto it, augmenting reality such that we are able to interact with the plotted artifacts. The user can physically move the Android device around the image target and see the dig site model from any perspective. The user can also move the device closer to the model in order to "zoom" into the view of a particular section of the model and its associated artifacts. This is especially useful, as the dig site model and the collection of artifacts are very detailed. The artifacts are plotted as points, colored by type. The user can touch the virtual points to trigger a popup information window that contains details of the artifact, such as photographs, material descriptions, and more.

  17. Behaviour of Steel Arch Stabilized by a Textile Membrane

    NASA Astrophysics Data System (ADS)

    Svoboda, O.; Machacek, J.

    2015-11-01

    Behaviour of the slender steel arch supporting textile membranes in a membrane structure with respect to in-plane and out-of plane stability is investigated in the paper. In the last decades the textile membranes have been widely used to cover both common and exclusive structures due to progress in new membrane materials with eminent properties. Nevertheless, complex analysis of such membranes in interaction with steel structure (carbon/stainless steel perimeter or supporting elements) is rather demanding, even with specialized software. Laboratory model of a large membrane structure simulating a shelter roof of a concert stage was tested and the resulting stress/deflection values are presented. The model of a reasonable size was provided with prestressed membrane of PVC coated polyester fabric Ferrari® Précontraint 702S and tested under various loadings. The supporting steel structure consisted of two steel arch tubes from S355 grade steel and perimeter prestressed cables. The stability behaviour of the inner tube was the primary interest of the investigation. The SOFiSTiK software was used to analyse the structural behaviour in 3D. Numerical non-linear analysis of deflections and internal forces of the structure under symmetrical and asymmetrical loadings covers various membrane prestressing and specific boundary conditions. The numerical results are validated using test results. Finally, the preliminary recommendations for appropriate numerical modelling and stability design of the supporting structure are presented.

  18. Evolution of magnetic topology of an erupting arched laboratory magnetoplasma

    NASA Astrophysics Data System (ADS)

    Tripathi, S.; Gekelman, W. N.

    2013-12-01

    Arched magnetoplasma structures ubiquitously exist in the solar atmosphere and affect energetic phenomena such as flares and coronal mass ejections. Presence of an electrical current in such structures generates a twisted magnetic-field and the term arched magnetic flux rope (AMFR) is used for them. In the limit of low electrical current (compared to the current-threshold for the kink instability), the magnetic twist in an AMFR becomes small and it resembles the structure of an arched magnetic flux tube. However, the term arched magnetic flux rope can be used for arched magnetoplasma structures without any loss of generality. We report results on the evolution of the magnetic topology of an erupting laboratory AMFR during its eruption. The AMFR (plasma β ≈ 10-3, Lundquist number ≈ 102-105, AMFR radius/ion-gyroradius ≈ 20, B ≈ 1000 Gauss at footpoints) is created using a lanthanum hexaboride (LaB6) plasma source and it evolves in an ambient magnetoplasma produced by another LaB6 source (See Ref. [2] for details of the experiment). The eruption is triggered by gradually increasing the electrical current in the AMFR and its evolution is captured by a fast-CCD camera. The relative magnitudes of the parameters of the AMFR and the ambient magnetoplasma can be varied to simulate a variety of conditions relevant to solar eruptions. The experiment runs continuously with a 0.5 Hz repetition rate. Hence, the plasma parameters of the AMFR are recorded with a good spatiotemporal resolution (spatial-resolution/AMFR-length ≈ 10-2 - 10-3, temporal-resolution/eruption-time ≈ 10-3) using computer-controlled movable probes. The three-dimensional magnetic-field of the AMFR is directly measured using a three-axis magnetic-loop probe. The pre-eruption phase of the AMFR remains quiescent for ≈ 100 Alfven transit times and the camera images evince a persistent appearance of the AMFR during this phase. In contrast, the post-eruption phase of the AMFR is associated with

  19. Non-equilibrium DMFT - Polaritonics

    NASA Astrophysics Data System (ADS)

    Lubatsch, Andreas; Frank, Regine

    Non-equilibrium physics recently really becomes important with the progress of ultrafast laser sciences. However in our understanding there is still a gap between equilibrium physics and the non-equilibrium, even though numerical methods have been advanced in recent years. We compare in this talk novel results at hand with equilibrium physics. The comparison will show that especially theoretical efforts are needed to explain many - so far - unresolved problems and to predict novel research on the basis of ab initio computing. We specifically discuss several non-equilibrium extensions of DMFT, numerical methods as well as semi-analytical solvers.

  20. Thermal equilibrium of goats.

    PubMed

    Maia, Alex S C; Nascimento, Sheila T; Nascimento, Carolina C N; Gebremedhin, Kifle G

    2016-05-01

    The effects of air temperature and relative humidity on thermal equilibrium of goats in a tropical region was evaluated. Nine non-pregnant Anglo Nubian nanny goats were used in the study. An indirect calorimeter was designed and developed to measure oxygen consumption, carbon dioxide production, methane production and water vapour pressure of the air exhaled from goats. Physiological parameters: rectal temperature, skin temperature, hair-coat temperature, expired air temperature and respiratory rate and volume as well as environmental parameters: air temperature, relative humidity and mean radiant temperature were measured. The results show that respiratory and volume rates and latent heat loss did not change significantly for air temperature between 22 and 26°C. In this temperature range, metabolic heat was lost mainly by convection and long-wave radiation. For temperature greater than 30°C, the goats maintained thermal equilibrium mainly by evaporative heat loss. At the higher air temperature, the respiratory and ventilation rates as well as body temperatures were significantly elevated. It can be concluded that for Anglo Nubian goats, the upper limit of air temperature for comfort is around 26°C when the goats are protected from direct solar radiation. PMID:27157333

  1. 49 CFR 230.61 - Arch tubes, water bar tubes, circulators and thermic siphons.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MAINTENANCE STANDARDS Boilers and Appurtenances Washing Boilers § 230.61 Arch tubes, water bar tubes, circulators and thermic siphons. (a) Frequency of cleaning. Each time the boiler is washed, arch tubes and water bar tubes shall thoroughly be cleaned mechanically, washed, and inspected. Circulators and...

  2. Congenital anomaly of craniovertebral junction: atlas-dens fusion with C1 anterior arch cleft.

    PubMed

    Pérez-Vallina, José R; Riaño-Galán, Isolina; Cobo-Ruisánchez, Angeles; Orejas-Rodriguez-Arango, Gonzalo; López-Muñiz, Carlos; Fernández-Martínez, José M

    2002-02-01

    A rare case of congenital atlantoaxial block is reported. A 13-year-old boy had a fusion of a non-separated odontoid process with the anterior arch of the atlas, in association with an anterior midline C1 arch cleft. PMID:11891461

  3. Obstructive membrane in arch of aorta in a case of Shone's complex

    PubMed Central

    Sadadiwala, Divyesh H.; Soni, Kunal A.

    2015-01-01

    Shone's complex is a rare congenital heart disease consisting of multisite obstruction on the left side of the heart. The obstructive membrane in the arch of aorta is never described among these obstructions. We report echocardiographic findings in a patient with Shone's complex with the obstructive membrane in the arch of aorta. PMID:26139755

  4. Stability of clogging arches in a silo submitted to vertical vibrations

    NASA Astrophysics Data System (ADS)

    Lozano, C.; Zuriguel, I.; Garcimartín, A.

    2015-06-01

    We present experimental results on the endurance of arches that block the outlet of a two-dimensional silo when subjected to vertical vibration. In a recent paper [C. Lozano et al., Phys. Rev. Lett. 109, 068001 (2012), 10.1103/PhysRevLett.109.068001], it was shown that the arch resistance against vibrations is determined by the maximum angle among those formed between each particle in the bridge and its two neighbors: the larger the maximum angle is, the weaker the bridge. It has also been reported that the breaking time distribution shows a power-law tail with an exponent that depends on the outlet size, the vibration intensity, and the load [I. Zuriguel et al., Sci. Rep. 4, 7324 (2014), 10.1038/srep07324]. Here we connect these previous works, demonstrating the importance of the maximum angle in the arch on the exponent of the breaking time distribution. Besides, we find that the acceleration needed to break an arch does not depend on the ramp rate of the applied acceleration, but it does depend on the outlet size above which the arch is formed. We also show that high frequencies of vibration reveal a change in the behavior of the arches that endure very long times. These arches have been identified as a subset with special geometrical features. Therefore, arches that cannot be broken by means of a given external excitation might exist.

  5. "Roller coaster maneuver via lateral orbital approach" for reduction of isolated zygomatic arch fractures.

    PubMed

    Pilanci, Ozgur; Basaran, Karaca; Datli, Asli; Kuvat, Samet Vasfi

    2013-11-01

    Numerous techniques have been reported for the reduction of zygomatic arch fractures. In this article, we aimed to describe a technique we named as "roller coaster maneuver via lateral orbital approach" to closed reduction of the isolated-type zygomatic arch fractures. Surgical outcomes of 14 patients treated with this method were outlined. PMID:24220411

  6. Clinical Advantages and Limitations of Monolithic Zirconia Restorations Full Arch Implant Supported Reconstruction: Case Series

    PubMed Central

    Carames, Joao; Yu, Yung Cheng Paul; Pérez, Alejandro; Kang, Mary

    2015-01-01

    Purpose. The purpose of this retrospective case series is to evaluate the clinical advantages and limitations of monolithic zirconia restorations for full arch implant supported restorations and report the rate of complications up to 2 years after insertion. Materials and Methods. Fourteen patients received implant placement for monolithic zirconia full arch reconstructions. Four implants were placed in seven arches, eleven arches received six implants, two arches received seven implants, two arches received eight implants, and one arch received nine implants. Results. No implant failures or complications were reported for an implant survival rate of 100% with follow-up ranging from 3 to 24 months. Conclusions. Monolithic zirconia CAD-/CAM-milled framework restorations are a treatment option for full arch restorations over implants, showing a 96% success rate in the present study. Some of the benefits are accuracy, reduced veneering porcelain, and minimal occlusal adjustments. The outcome of the present study showed high success in function, aesthetics, phonetics, and high patient satisfaction. PMID:26124835

  7. 49 CFR 230.61 - Arch tubes, water bar tubes, circulators and thermic siphons.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Arch tubes, water bar tubes, circulators and... MAINTENANCE STANDARDS Boilers and Appurtenances Washing Boilers § 230.61 Arch tubes, water bar tubes... water bar tubes shall thoroughly be cleaned mechanically, washed, and inspected. Circulators and...

  8. 49 CFR 230.61 - Arch tubes, water bar tubes, circulators and thermic siphons.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Arch tubes, water bar tubes, circulators and... MAINTENANCE STANDARDS Boilers and Appurtenances Washing Boilers § 230.61 Arch tubes, water bar tubes... water bar tubes shall thoroughly be cleaned mechanically, washed, and inspected. Circulators and...

  9. Imaging a boa constrictor--the incomplete double aortic arch syndrome.

    PubMed

    Narayan, Rajeev L; Kanwar, Anubhav; Jacobi, Adam; Sanz, Javier

    2012-11-01

    Incomplete double aortic arch is a rare anomaly resulting from atresia rather than complete involution in the distal left arch resulting in a non-patent fibrous cord between the left arch and descending thoracic aorta. This anatomic anomaly may cause symptomatic vascular rings, leading to stridor, wheezing, or dysphagia, requiring surgical transection of the fibrous cord. Herein, we describe an asymptomatic 59 year-old man presenting for contrast-enhanced CT angiography to assess cardiac anatomy prior to radiofrequency ablation, who was incidentally found to have an incomplete double aortic arch with hypoplasia of the left arch segment and an aortic diverticulum. Recognition of this abnormality by imaging is important to inform both corrective surgery in symptomatic patients, as well as assist in the planning of percutaneous coronary and vascular interventions. PMID:22542042

  10. Mathematical and descriptive classification of variations in dental arch shape in an Australian aborigine population.

    PubMed

    McKee, J K; Molnar, S

    1988-01-01

    The ability to describe dental arch shape is necessary for biomechanical studies of occlusion as well as for anthropological studies of human and primate dental variation. A mathematical method of describing and classifying human dental arch shape was used to assess the nature of individual variability. The method involved the calculation of a series of third-degree polynomials which were fitted to coordinate points along the dental arcade. The slopes of the polynomials, evaluated at these coordinate points, provided a multivariate description of shape, independent of arch size. Graphic representations of arch shape could be constructed from the polynomial equations. These mathematical techniques were used in association with multivariate and univariate statistics to explore the types of variability in dental arch shape among a population of Australian aborigines. The results illustrated the ambiguities of conventional subjective classifications. PMID:3256297

  11. A shared role for sonic hedgehog signalling in patterning chondrichthyan gill arch appendages and tetrapod limbs.

    PubMed

    Gillis, J Andrew; Hall, Brian K

    2016-04-15

    Chondrichthyans (sharks, skates, rays and holocephalans) possess paired appendages that project laterally from their gill arches, known as branchial rays. This led Carl Gegenbaur to propose that paired fins (and hence tetrapod limbs) originally evolved via transformation of gill arches. Tetrapod limbs are patterned by asonic hedgehog(Shh)-expressing signalling centre known as the zone of polarising activity, which establishes the anteroposterior axis of the limb bud and maintains proliferative expansion of limb endoskeletal progenitors. Here, we use loss-of-function, label-retention and fate-mapping approaches in the little skate to demonstrate that Shh secretion from a signalling centre in the developing gill arches establishes gill arch anteroposterior polarity and maintains the proliferative expansion of branchial ray endoskeletal progenitor cells. These findings highlight striking parallels in the axial patterning mechanisms employed by chondrichthyan branchial rays and paired fins/limbs, and provide mechanistic insight into the anatomical foundation of Gegenbaur's gill arch hypothesis. PMID:27095494

  12. Statistical physics ""Beyond equilibrium

    SciTech Connect

    Ecke, Robert E

    2009-01-01

    The scientific challenges of the 21st century will increasingly involve competing interactions, geometric frustration, spatial and temporal intrinsic inhomogeneity, nanoscale structures, and interactions spanning many scales. We will focus on a broad class of emerging problems that will require new tools in non-equilibrium statistical physics and that will find application in new material functionality, in predicting complex spatial dynamics, and in understanding novel states of matter. Our work will encompass materials under extreme conditions involving elastic/plastic deformation, competing interactions, intrinsic inhomogeneity, frustration in condensed matter systems, scaling phenomena in disordered materials from glasses to granular matter, quantum chemistry applied to nano-scale materials, soft-matter materials, and spatio-temporal properties of both ordinary and complex fluids.

  13. New technique for retrograde cerebral perfusion during arch aneurysm repair.

    PubMed

    Bartoccioni, S; Lanzillo, G; deJong, A A; Fiaschini, P; Martinelli, G; Fedeli, C; Di Lazarro, D; Mercati, U

    1995-09-01

    Many techniques are used to reduce brain damage during surgery for dissecting aneurysms of the ascending aorta and arch. Recently, new techniques of protection were proposed, consistent with hypothermic circulatory arrest in association with retrograde cerebral perfusion via superior vena cava. We propose a simple, time-saving method, which does not require any manipulation of the heart. We use a multilumen cannula for cardioplegia (D 860-DIDECO FUNDARO') with pressure transducer. This cannula is inserted in superior vena cava by means of a simple purse-string, and linked to the arterial line with a "Y" derivation, allowing retrograde perfusion of the brain and monitoring the perfusion pressure at every moment. The superior vena cava placed downstream from the cannula is closed by a small vascular clamp, to avoid blood reflux in the right atrium. This method is time- and money-saving, is readily available, and can be prepared whenever necessary, also in the middle of the surgical procedure. PMID:7488786

  14. Double arch mirror study. Part 1: Preliminary engineering report

    NASA Technical Reports Server (NTRS)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    In the proposed design, the NASA AMES 20-in double arch mirror is supported by three clamp and flexure assemblies. The mirror clamp consists of a T-shaped Invar-36 member that goes into a similarly shaped socket in the back of the mirror. The mirror socket is made oversize and contacts the clamp only along the conical surface. The clamp is preloaded by a spring washer and pulls the mirror into contact with the flexure. The clamp is then inserted into the mirror socket through a cutout, is rotated 90 deg, and is then pinned in place. Loading conditions considered in socket design are discussed as well as stress in the socket and clamp. Flexure geometry and stress are examined as well as the effects of flexure error and of mirror cell error.

  15. Angioleiomyoma of the Plantar-Medial Arch: A Case Report

    PubMed Central

    Gilheany, Mark

    2016-01-01

    An angioleiomyoma is a benign soft tissue tumour that arises from smooth muscle layer of blood vessels. The true aetiology of these masses is largely unknown and quite often may not be associated with pain. This paper illustrates the occurrence of an angioleiomyoma in the medial arch of the foot, a previously unreported location. Significant delay occurred in the patient being referred for specialist consultation, after attending numerous general practitioners for management. This highlighted the need for ongoing publication for case reports of this nature. The patient underwent excision with no recurrence of the lesion reported at 12 months. Often masses of this type may be left alone. However, when symptomatic simple excision will suffice where no other surrounding complication exists and where the mass is well encapsulated in the sub cutaneous area.

  16. Mycotic aneurysm of the distal aortic arch caused by Aspergillus.

    PubMed

    Hosono, Mitsuharu; Hattori, Koji; Shibata, Toshihiko; Sasaki, Yasuyuki; Hirai, Hidekazu; Suehiro, Shigefumi

    2006-04-01

    We describe an unusual case of a thoracic aortic aneurysm caused by Aspergillus. A 70-year-old man underwent prednisolone and Ara-C treatments for a myelodysplastic syndrome. Blood examination revealed pancytopenia. Under these treatments, an aneurysm presented at the distal aortic arch. He underwent resection of the aneurysm with a graft repair covered by a pedicled omentum flap, followed by prolonged administration of micafungin and itraconazole for a mycotic aneurysm. The postoperative course was favorable without complications. Serum C-reactive protein became negative and he was discharged 2 months after the surgery. However, 4 months after the surgery, he died from worsening of the myelodysplastic syndrome. The prognosis for patients with mycotic aneurysms is poor due to their immunocompetent condition arising from underlying diseases. Therefore, in addition to prompt treatment with antifungal agents combined with surgical debridement, control of the underlying disease is essential for improving the outcome. PMID:16642922

  17. The randomized shortened dental arch study: tooth loss.

    PubMed

    Walter, M H; Weber, A; Marré, B; Gitt, I; Gerss, J; Hannak, W; Hartmann, S; Heydecke, G; Huppertz, J; Jahn, F; Ludwig, A; Mundt, T; Kern, M; Klein, V; Pospiech, P; Stumbaum, M; Wolfart, S; Wöstmann, B; Busche, E; Böning, K; Luthardt, R G

    2010-08-01

    The evidence concerning the management of shortened dental arch (SDA) cases is sparse. This multi-center study was aimed at generating data on outcomes and survival rates for two common treatments, removable dental prostheses (RDP) for molar replacement or no replacement (SDA). The hypothesis was that the treatments lead to different incidences of tooth loss. We included 215 patients with complete molar loss in one jaw. Molars were either replaced by RDP or not replaced, according to the SDA concept. First tooth loss after treatment was the primary outcome measure. This event occurred in 13 patients in the RDP group and nine patients in the SDA group. The respective Kaplan-Meier survival rates at 38 months were 0.83 (95% CI: 0.74-0.91) in the RDP group and 0.86 (95% CI: 0.78-0.95) in the SDA group, the difference being non-significant. PMID:20400723

  18. Reassessing the Dlx code: the genetic regulation of branchial arch skeletal pattern and development

    PubMed Central

    Depew, Michael J; Simpson, Carol A; Morasso, Maria; Rubenstein, John LR

    2005-01-01

    The branchial arches are meristic vertebrate structures, being metameric both between each other within the rostrocaudal series along the ventrocephalic surface of the embryonic head and within each individual arch: thus, just as each branchial arch must acquire a unique identity along the rostrocaudal axis, each structure within the proximodistal axis of an arch must also acquire a unique identity. It is believed that regional specification of metameric structures is controlled by the nested expression of related genes resulting in a regional code, a principal that is though to be demonstrated by the regulation of rostrocaudal axis development in animals exerted by the nested HOM-C/Hox homeobox genes. The nested expression pattern of the Dlx genes within the murine branchial arch ectomesenchyme has more recently led to the proposal of a Dlx code for the regional specification along the proximodistal axis of the branchial arches (i.e. it establishes intra-arch identity). This review re-examines this hypothesis, and presents new work on an allelic series of Dlx loss-of-function mouse mutants that includes various combinations of Dlx1, Dlx2, Dlx3, Dlx5 and Dlx6. Although we confirm fundamental aspects of the hypothesis, we further report a number of novel findings. First, contrary to initial reports, Dlx1, Dlx2 and Dlx1/2 heterozygotes exhibit alterations of branchial arch structures and Dlx2−/− and Dlx1/2−/− mutants have slight alterations of structures derived from the distal portions of their branchial arches. Second, we present evidence for a role for murine Dlx3 in the development of the branchial arches. Third, analysis of compound Dlx mutants reveals four grades of mandibular arch transformations and that the genetic interactions of cis first-order (e.g. Dlx5 and Dlx6), trans second-order (e.g. Dlx5 and Dlx2) and trans third-order paralogues (e.g. Dlx5 and Dlx1) result in significant and distinct morphological differences in mandibular arch development

  19. The Nash equilibrium: a perspective.

    PubMed

    Holt, Charles A; Roth, Alvin E

    2004-03-23

    In 1950, John Nash contributed a remarkable one-page PNAS article that defined and characterized a notion of equilibrium for n- person games. This notion, now called the "Nash equilibrium," has been widely applied and adapted in economics and other behavioral sciences. Indeed, game theory, with the Nash equilibrium as its centerpiece, is becoming the most prominent unifying theory of social science. In this perspective, we summarize the historical context and subsequent impact of Nash's contribution. PMID:15024100

  20. Grinding kinetics and equilibrium states

    NASA Technical Reports Server (NTRS)

    Opoczky, L.; Farnady, F.

    1984-01-01

    The temporary and permanent equilibrium occurring during the initial stage of cement grinding does not indicate the end of comminution, but rather an increased energy consumption during grinding. The constant dynamic equilibrium occurs after a long grinding period indicating the end of comminution for a given particle size. Grinding equilibrium curves can be constructed to show the stages of comminution and agglomeration for certain particle sizes.

  1. Outcomes of single-stage total arch replacement via clamshell incision

    PubMed Central

    2011-01-01

    Background Treatment of complex aortic pathologies involving the transverse arch with extensive involvement of the descending aorta remains a surgical challenge. Since clamshell incision provides superior exposure of the entire thoracic aorta, we evaluated the use of this technique for single-stage total arch replacement by arch vessel reconstruction. Methods The arch-first technique combined with clamshell incision was used in 38 cases of aneurysm and aortic disease in 2008 and 2009. Extensive total arch replacement was used with clamshell incision for reconstruction of arch vessels under deep hypothermic circulatory arrest. Results Overall 30-day mortality was 13%. The mean operating time was approximately 8 hours. Deep hypothermia resulted in mean CPB time exceeding 4.5 hours and mean duration of circulatory arrest was 25 minutes. The overall postoperative temporary and permanent neurologic dysfunction rates were 3% and 3% for elective and 3% and 0% for emergency surgery, respectively. All patients except the five who died in hospital were discharged without nursing care after an average post-operative hospital stay of 35 days. Conclusions The arch-first technique, combined with clamshell incision, provides expeditious replacement of the thoracic aorta with an acceptable duration of hypothermic circulatory arrest and minimizes the risk of retrograde atheroembolism by using antegrade perfusion. PMID:21933402

  2. Relationship between lumbar changes and modifications in the plantar arch in women with low back pain

    PubMed Central

    Borges, Cláudia dos Santos; Fernandes, Luciane Fernanda Rodrigues Martinho; Bertoncello, Dernival

    2013-01-01

    OBJECTIVE : Evaluate the probable relationship among plantar arch, lumbar curvature, and low back pain. METHODS : Fifteen healthy women were assessed taking in account personal data and anthropometric measurements, photopodoscopic evaluation of the plantar arch, and biophotogrammetric postural analysis of the patient (both using the SAPO software), as well as evaluation of lumbar pain using a Visual Analog Scale (VAS). The average age of the participants was 30.45 (±6.25) years. RESULTS : Of the feet evaluated, there were six individuals with flat feet, five with high arch, and four with normal feet. All reported algic syndrome in the lumbar spine, with the highest VAS values for the volunteers with high arch. Correlation was observed between the plantar arch and the angle of the lumbar spine (r = -0.71, p = 0.004) Conclusion: High arch was correlated with more intense algic syndrome, while there was moderate positive correlation between flat foot and increased lumbar curvature, and between high arch and lumbar correction. Level of Evidence IV. Case Series. PMID:24453656

  3. [Effects of removable partial dentures on the quality of life in people with shortened dental arches].

    PubMed

    Armellini, D B; Heydecke, G; Witter, D J; Creugers, N H J

    2009-12-01

    In order to assess the enhanced value of removable partial dentures on the quality of life, patients at 2 university clinics were screened for the presence of complete or shortened dental arches. Those selected were assigned to 1 of 5 subgroups: 1) a shortened dental arch with all frontal teeth, 2) a shortened dental arch with one or more frontal diastemas, 3) a shortened dental arch with all frontal teeth, restored by a removable partial denture, 4) a shortened dental arch and several diastemas, restored by a removable partial denture, 5) a complete dental arch. The participants completed the Oral Health Impact Profile (OHIP-49) and the Short Form Health Survey (SF-36). Clinical data recorded were: whether any teeth were missing and if so which, whether or not these had been replaced by a removable partial denture, and the number of occluding pairs of (pre)molars. The results revealed that a shortenend dental arch has a certain impact on the quality of life. However, the participants only experienced benefits from a removable partial denture if the denture also replaced frontal teeth. PMID:20101937

  4. The role of the zygomatic arch in the statics of the skull and its adaptive shape.

    PubMed

    Witzel, U; Preuschoft, H; Sick, H

    2004-01-01

    The zygomatic arch of mammals is usually considered a phylogenetic relic of the fenestrations of the skull roof which may be observed in morphological sequences of primitive vertebrate skulls. If this concept is correct, the element is comparable (though not homologous) to the jugal arches of diapsid reptiles. Two major questions then remain unanswered: why different elements are maintained in reptiles and mammals during evolution, and why the arches are maintained as relics of ancestral forms. It is tempting to respond to the latter question with a very simple answer, namely that the elements function in order to sustain mechanical stresses. In this paper, we raise the questions which quality of stresses occurs in a primate skull within the zygomatic arches and what relationship these stresses hold to the morphology of these bony elements. An answer has been sought by means of finite element stress analysis. We found that the zygomatic arch in primate skulls represents a structure which carries, under all biologically relevant conditions, either compressive or tensile stresses. In a very simple model of the human skull under bite forces, a strip of stresses occurs lateral to the orbits, which seems roughly comparable to the zygomatic arch. Once such a structure exists and is used as an insertion of adductor muscles, it will be exposed to bending stress in side view and in frontal view. Morphological details of the zygomatic arch (curvature, profile, suture) are well suited to sustain the evoked stresses by a minimum of material. PMID:15316151

  5. Napoleon Is in Equilibrium

    PubMed Central

    Phillips, Rob

    2016-01-01

    It has been said that the cell is the test tube of the twenty-first century. If so, the theoretical tools needed to quantitatively and predictively describe what goes on in such test tubes lag sorely behind the stunning experimental advances in biology seen in the decades since the molecular biology revolution began. Perhaps surprisingly, one of the theoretical tools that has been used with great success on problems ranging from how cells communicate with their environment and each other to the nature of the organization of proteins and lipids within the cell membrane is statistical mechanics. A knee-jerk reaction to the use of statistical mechanics in the description of cellular processes is that living organisms are so far from equilibrium that one has no business even thinking about it. But such reactions are probably too hasty given that there are many regimes in which, because of a separation of timescales, for example, such an approach can be a useful first step. In this article, we explore the power of statistical mechanical thinking in the biological setting, with special emphasis on cell signaling and regulation. We show how such models are used to make predictions and describe some recent experiments designed to test them. We also consider the limits of such models based on the relative timescales of the processes of interest. PMID:27429713

  6. Napoleon Is in Equilibrium

    NASA Astrophysics Data System (ADS)

    Phillips, Rob

    2015-03-01

    It has been said that the cell is the test tube of the twenty-first century. If so, the theoretical tools needed to quantitatively and predictively describe what goes on in such test tubes lag sorely behind the stunning experimental advances in biology seen in the decades since the molecular biology revolution began. Perhaps surprisingly, one of the theoretical tools that has been used with great success on problems ranging from how cells communicate with their environment and each other to the nature of the organization of proteins and lipids within the cell membrane is statistical mechanics. A knee-jerk reaction to the use of statistical mechanics in the description of cellular processes is that living organisms are so far from equilibrium that one has no business even thinking about it. But such reactions are probably too hasty given that there are many regimes in which, because of a separation of timescales, for example, such an approach can be a useful first step. In this article, we explore the power of statistical mechanical thinking in the biological setting, with special emphasis on cell signaling and regulation. We show how such models are used to make predictions and describe some recent experiments designed to test them. We also consider the limits of such models based on the relative timescales of the processes of interest.

  7. Origin and structural development of the LaSalle Arch, Louisiana

    SciTech Connect

    Lawless, P.N. )

    1990-05-01

    The LaSalle arch is a basement high separating the Louisiana and Mississippi interior salt basins. Using reflection seismic data, an area located on the southern end of the LaSalle arch was shown to be composed of relict Paleozoic continental crust that was left behind and partially rifted during the breakup of Pangea during the Triassic. Rifting preferentially occurred to the north of a Paleozoic thrust fault nose, and crustal extension took place in a northeast-southwest direction. The LaSalle arch, as seen in post-Triassic stratigraphy, formed by a two-part process. The western limb developed syndepositionally due to differential subsidence, and the eastern limb developed due to relative regional tilting to the east after deposition of the Claibornian Sparta Formation. The LaSalle arch acted as only a minor impediment to sediment transport with a very low relief except during the Tayloran Stage of the Upper Cretaceous. A single truncational unconformity in post-Triassic stratigraphy is present in the Taylora Demopolis Formation, indicating a period of relatively major uplift by the LaSalle arch. This contrast, with the Sabine arch in eastern Texas; the Sabine arch experienced uplift during the Eagle Fordian and Sabinian stages. A recently proposed hypothesis calling for overthrusting in the Western Cordillera as the mechanism for uplift on the Sabine arch cannot explain movement of the LaSalle arch because horizontal stress would predict synchronous uplift of basement highs. A more satisfactory uplift mechanism calls upon lateral heat flow from the mantle as the driving force for uplift.

  8. The Role of Arch Compression and Metatarsophalangeal Joint Dynamics in Modulating Plantar Fascia Strain in Running

    PubMed Central

    McDonald, Kirsty A.; Stearne, Sarah M.; Alderson, Jacqueline A.; North, Ian; Pires, Neville J.; Rubenson, Jonas

    2016-01-01

    Elastic energy returned from passive-elastic structures of the lower limb is fundamental in lowering the mechanical demand on muscles during running. The purpose of this study was to investigate the two length-modulating mechanisms of the plantar fascia, namely medial longitudinal arch compression and metatarsophalangeal joint (MPJ) excursion, and to determine how these mechanisms modulate strain, and thus elastic energy storage/return of the plantar fascia during running. Eighteen runners (9 forefoot and 9 rearfoot strike) performed three treadmill running trials; unrestricted shod, shod with restricted arch compression (via an orthotic-style insert), and barefoot. Three-dimensional motion capture and ground reaction force data were used to calculate lower limb kinematics and kinetics including MPJ angles, moments, powers and work. Estimates of plantar fascia strain due to arch compression and MPJ excursion were derived using a geometric model of the arch and a subject-specific musculoskeletal model of the plantar fascia, respectively. The plantar fascia exhibited a typical elastic stretch-shortening cycle with the majority of strain generated via arch compression. This strategy was similar in fore- and rear-foot strike runners. Restricting arch compression, and hence the elastic-spring function of the arch, was not compensated for by an increase in MPJ-derived strain. In the second half of stance the plantar fascia was found to transfer energy between the MPJ (energy absorption) and the arch (energy production during recoil). This previously unreported energy transfer mechanism reduces the strain required by the plantar fascia in generating useful positive mechanical work at the arch during running. PMID:27054319

  9. The Role of Arch Compression and Metatarsophalangeal Joint Dynamics in Modulating Plantar Fascia Strain in Running.

    PubMed

    McDonald, Kirsty A; Stearne, Sarah M; Alderson, Jacqueline A; North, Ian; Pires, Neville J; Rubenson, Jonas

    2016-01-01

    Elastic energy returned from passive-elastic structures of the lower limb is fundamental in lowering the mechanical demand on muscles during running. The purpose of this study was to investigate the two length-modulating mechanisms of the plantar fascia, namely medial longitudinal arch compression and metatarsophalangeal joint (MPJ) excursion, and to determine how these mechanisms modulate strain, and thus elastic energy storage/return of the plantar fascia during running. Eighteen runners (9 forefoot and 9 rearfoot strike) performed three treadmill running trials; unrestricted shod, shod with restricted arch compression (via an orthotic-style insert), and barefoot. Three-dimensional motion capture and ground reaction force data were used to calculate lower limb kinematics and kinetics including MPJ angles, moments, powers and work. Estimates of plantar fascia strain due to arch compression and MPJ excursion were derived using a geometric model of the arch and a subject-specific musculoskeletal model of the plantar fascia, respectively. The plantar fascia exhibited a typical elastic stretch-shortening cycle with the majority of strain generated via arch compression. This strategy was similar in fore- and rear-foot strike runners. Restricting arch compression, and hence the elastic-spring function of the arch, was not compensated for by an increase in MPJ-derived strain. In the second half of stance the plantar fascia was found to transfer energy between the MPJ (energy absorption) and the arch (energy production during recoil). This previously unreported energy transfer mechanism reduces the strain required by the plantar fascia in generating useful positive mechanical work at the arch during running. PMID:27054319

  10. Footprint-based estimates of arch structure are confounded by body composition in adults.

    PubMed

    Wearing, Scott C; Grigg, Nicole L; Lau, Hin C; Smeathers, James E

    2012-08-01

    Previous research employing indirect measures of arch structure, such as those derived from footprints, have indicated that obesity results in a "flatter" foot type. In the absence of radiographic measures, however, definitive conclusions regarding the osseous alignment of the foot cannot be made. We determined the effect of body mass index (BMI) on radiographic and footprint-based measures of arch structure. The research was a cross-sectional study in which radiographic and footprint-based measures of foot structure were made in 30 subjects (10 males, 20 female) in addition to standard anthropometric measures of height, weight, and BMI. Multiple (univariate) regression analysis demonstrated that both BMI (β = 0.39, t(26) = 2.12, p = 0.04) and radiographic arch alignment (β = 0.51, t(26) = 3.32, p < 0.01) were significant predictors of footprint-based measures of arch height after controlling for all variables in the model (R(2) = 0.59, F(3,26) = 12.3, p < 0.01). In contrast, radiographic arch alignment was not significantly associated with BMI (β = -0.03, t(26) = -0.13, p = 0.89) when Arch Index and age were held constant (R(2) = 0.52, F(3,26) = 9.3, p < 0.01). Adult obesity does not influence osseous alignment of the medial longitudinal arch, but selectively distorts footprint-based measures of arch structure. Footprint-based measures of arch structure should be interpreted with caution when comparing groups of varying body composition. PMID:22227795

  11. Arched-outer-race ball-bearing analysis considering centrifugal forces

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Anderson, W. J.

    1972-01-01

    A first-order thrust load analysis that considers centrifugal forces but which neglects gyroscopics, elastohydrodynamics, and thermal effects was performed. The analysis was applied to a 150-mm-bore angular-contact ball bearing. Fatigue life, contact loads, and contact angles are shown for conventional and arched bearings. The results indicate that an arched bearing is highly desirable for high-speed applications. In particular, at an applied load of 4448 n (1000 lb) and a DN value of 3 million (20,000 rpm) the arched bearing shows an improvement in life of 306 percent over that of a conventional bearing.

  12. Influence of Process Parameters on Forming of Arched Aircraft Skin with Aluminum Alloy 2024

    NASA Astrophysics Data System (ADS)

    Yan, Huajun; Zhang, Shuangjie; Gao, Ying

    To solve these problems such as easily springback and hardly controlling the loading direction when arched aircraft skin is formed, stretch forming of steel plate with aluminium alloy 2024 was simulated by the finite element software Abaqus, and the shape of the stretch forming die was the arc with radius 350mm. The influence of process parameters, such as stretch forming track and dangling length on forming of arched aircraft skin was researched, and the reasonable range of stretch forming length track and dangling length was given. The results have significance for research the forming law of arched aircraft skin.

  13. Rapid-Equilibrium Enzyme Kinetics

    ERIC Educational Resources Information Center

    Alberty, Robert A.

    2008-01-01

    Rapid-equilibrium rate equations for enzyme-catalyzed reactions are especially useful because if experimental data can be fit by these simpler rate equations, the Michaelis constants can be interpreted as equilibrium constants. However, for some reactions it is necessary to use the more complicated steady-state rate equations. Thermodynamics is…

  14. Dental arch changes associated with rapid maxillary expansion: A retrospective model analysis study

    PubMed Central

    D’Souza, Ivor M; Kumar, H. C. Kiran; Shetty, K. Sadashiva

    2015-01-01

    Introduction: Transverse deficiency of the maxilla is a common clinical problem in orthodontics and dentofacial orthopedics. Transverse maxillary deficiency, isolated or associated with other dentofacial deformities, results in esthetic and functional impairment giving rise to several clinical manifestations such as asymmetrical facial growth, positional and functional mandibular deviations, altered dentofacial esthetics, adverse periodontal responses, unstable dental tipping, and other functional problems. Orthopedic maxillary expansion is the preferred treatment approach to increase the maxillary transverse dimension in young patients by splitting of the mid palatal suture. This orthopedic procedure has lately been subject of renewed interest in orthodontic treatment mechanics because of its potential for increasing arch perimeter to alleviate crowding in the maxillary arch without adversely affecting facial profile. Hence, the present investigation was conducted to establish a correlation between transverse expansion and changes in the arch perimeter, arch width and arch length. Methods: For this purpose, 10 subjects (five males, five females) were selected who had been treated by rapid maxillary expansion (RME) using hyrax rapid palatal expander followed by fixed mechanotherapy (PEA). Pretreatment (T1), postexpansion (T2), and posttreatment (T3) dental models were compared for dental changes brought about by RME treatment and its stability at the end of fixed mechanotherapy. After model measurements were made, the changes between T1–T2, T2–T3 and T1–T3 were determined for each patient. The mean difference between T1–T2, T2–T3 and T1–T3 were compared to assess the effects of RME on dental arch measurements. Results are expressed as mean ± standard deviation and are compared by repeated measures analysis of variance followed by a post-hoc test. Arch perimeter changes are correlated with changes in arch widths at the canine, premolar and molar regions

  15. Is Soret equilibrium a non-equilibrium effect?

    NASA Astrophysics Data System (ADS)

    Würger, Alois

    2013-04-01

    Recent thermophoretic experiments on colloidal suspensions revived an old debate, namely whether the Soret effect is properly described by thermostatics, or necessarily requires non-equilibrium thermodynamics. Based on colloidal transport theory and the entropy production of the related viscous flow, our analysis leads to the conclusion that the equilibrium approach may work for small ions, yet fails for colloidal particles and polymers. Regarding binary molecular mixtures, our results shed some doubt on the validity of thermostatic approaches that derive the Soret coefficient from equilibrium potentials.

  16. Exterior building details of Building D, west façade: brick arch ...

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

    Exterior building details of Building D, west façade: brick arch lintel over historic entry that was brick infilled; easterly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  17. Arch size distribution in a two-dimensional pile of disks

    NASA Astrophysics Data System (ADS)

    Aguirre, M. A.; Pugnaloni, L. A.; Divoux, T.; Grande, J. G.

    2009-06-01

    Arch formation in a granular pile is a dynamical process. Staring at a static pile one cannot identify such structures. Indeed, it is necessary to know which grains are in contact, but also to access the whole history of the packing formation to distinguish the contacts which really sustain arches. In a recent article, arch formation has been studied numerically [Arévalo et al., Phys. Rev. E 74, 021303 (2006)]. Here, we report preliminary results of an experiment which consists of a time-resolved study of arch formation during the deposition of a disk assembly. The whole experiment is horizontally set. A conveyor belt makes it possible to tune the disk deposition-rate and thus to follow entirely the deposition dynamics. We compare our experimental findings to the previously cited numerical study.

  18. Management of an elderly patient with respiratory failure due to double aortic arch

    PubMed Central

    Ryu, Changwan; Puchalski, Jonathan; Perkins, Michael; Honiden, Shyoko

    2015-01-01

    Vascular rings are congenital malformations of the aortic arch. A double aortic arch (DAA), the most common type of vascular ring, results from the failure of the fourth embryonic branchial arch to regress, leading to an ascending aorta that divides into a left and right arch that fuse together to completely encircle the trachea and esophagus. The subsequent DAA causes compressive effects on the trachea and esophagus that typically manifests in infancy or early childhood. Adult presentations, particularly in the elderly, are exceedingly rare. Historically such patients have a long-standing history of dyspnea on exertion and dysphagia, with many assumed to have obstructive lung or intrinsic cardiac disease. We describe a case of an elderly woman who presented with respiratory failure due to DAA. In her case, surgery was not feasible and we describe our experience with airway stenting.

  19. Prenatal diagnosis of tetralogy of Fallot with a double aortic arch.

    PubMed

    Cheng, Andrew L; Pruetz, Jay D; Kung, Grace C

    2016-06-01

    In this study, we present a case of prenatally diagnosed tetralogy of Fallot with a double aortic arch, correlating images from fetal echocardiography, transthoracic echocardiography, and cardiac MRI. PMID:26983561

  20. 49 CFR 230.61 - Arch tubes, water bar tubes, circulators and thermic siphons.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... accurately measures wall thickness at each annual inspection. All arch brick shall be removed for this inspection. If any are found with wall thickness reduced below that required to render them safe and...

  1. 49 CFR 230.61 - Arch tubes, water bar tubes, circulators and thermic siphons.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... accurately measures wall thickness at each annual inspection. All arch brick shall be removed for this inspection. If any are found with wall thickness reduced below that required to render them safe and...

  2. Endovascular repair of an aortic arch pseudoaneurysm with double chimney stent grafts: a case report

    PubMed Central

    2013-01-01

    Aortic arch pseudoaneurysm is a rare condition but carries a high risk of rupture. We report a case of a 45-year-old man with aortic arch pseudoaneurysm between left common carotid artery (LCCA) and left subclavian artery (LSA), in which a endovascular stent graft combined with double chimneys covered stents were successfully placed. There were no any complaints and complications after 12 months follow-up. The CTA demonstrated thrombus formation in the pseudoaneurysm lumen, no endoleak and the aortic arch, LCCA and LSA were all patent. We feel that the combined endovascular and double chimneys may be a valuable therapeutic alternative when treating aortic arch lesion. However, long-term clinical efficacy and safety have yet to be confirmed. PMID:23577875

  3. 3. South elevation, (1r) arches DE and EF. View north ...

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

    3. South elevation, (1-r) arches D-E and E-F. View north - Ashton Viaduct, State Route 116 (Washington Highway) spanning Blackstone River, Blackstone Canal, & Providence & Worcester Railroad, Ashton, Providence County, RI

  4. 2. South elevation, (1r) arches CD and DE. View north ...

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

    2. South elevation, (1-r) arches C-D and D-E. View north - Ashton Viaduct, State Route 116 (Washington Highway) spanning Blackstone River, Blackstone Canal, & Providence & Worcester Railroad, Ashton, Providence County, RI

  5. 13. Photograph of archItectural competition drawing; original in the possession ...

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

    13. Photograph of archItectural competition drawing; original in the possession of the Pennsylvania Hospital. John Haviland, architect, December 1833. PLAN OF THE BASEMENT - Pennsylvania Hospital, Eighth & Ninth, Pine & Spruce Streets, Philadelphia, Philadelphia County, PA

  6. Collapse displacements for a mechanism of spreading-induced supports in a masonry arch

    NASA Astrophysics Data System (ADS)

    Coccia, Simona; Di Carlo, Fabio; Rinaldi, Zila

    2015-09-01

    Masonry arch systems and vaulted structures constitute a structural typology widely spread in the historical building heritage. Small displacements of the supports, due to different causes, among which subsidence of foundation systems or movements of underlying structures can lead the masonry arch to a condition of collapse because of gradual change in its geometry. This paper presents a tool, based on a kinematic approach, for the computation of the magnitude of the displacements that cause the collapse of circular arches subject to dead loads, and allows the evaluation of the related thrust value. A parametric study has been carried out in order to develop a deeper understanding of the influence of the involved parameters. In addition, analytic formulations of the maximum allowed displacement and the associated thrust are proposed. Finally, a case study related to the behavior of a masonry arch on spreading-induced abutments is undertaken and discussed.

  7. Computed tomography angiography of hybrid thoracic endovascular aortic repair of the aortic arch.

    PubMed

    Akhtar, Nila J; Oderich, Gustavo S; Vrtiska, Terri J; Williamson, Eric E; Araoz, Philip A

    2013-05-01

    Endovascular repair of the aorta has traditionally been limited to the abdominal aorta and, more recently, the descending thoracic aorta. However, recently hybrid repairs (a combination of open surgical and endovascular repair) have made endovascular repair of the aortic arch possible. Hybrid repair of the aortic arch typically involves an open surgical debranching procedure that allows for revascularization of the aortic arch vessels and subsequent endovascular stent placement. These approaches avoid the deep hypothermic circulatory arrest required for full, open surgical repair of the aortic arch. In hybrid repairs, the stent landing zone determines which branch vessels will be covered and therefore need revascularization. This article will review the preprocedure assessment with computed tomography angiography, techniques for revascularization and postprocedure complications. PMID:23621141

  8. Successful repair of a syphilitic aortic arch aneurysm accompanied by serious cerebral infarction.

    PubMed

    Sato, Katsutoshi; Chiba, Kiyoshi; Koizumi, Nobusato; Ogino, Hitoshi

    2014-01-01

    We present a 52-year-old male with a syphilitic aortic arch aneurysm accompanied by relevant extensive cerebral infarction. He was admitted to a local hospital for sudden loss of consciousness, where he was diagnosed with serious cerebral infarction. During his treatment, a multilocular aortic arch aneurysm involving the arch vessels was found incidentally. He was transferred to our hospital for surgical treatment. A preoperative routine laboratory test for syphilis was highly positive, which suggested that the aneurysm was likely caused by syphilis and the cerebral infarction was also induced by the involvement of syphilitic aortitis or arteritis. After 2 weeks of antibiotic therapy for syphilis, total arch replacement was performed successfully using meticulous brain protection with antegrade selective cerebral perfusion and deep hypothermia. He recovered without any further cerebral deficits. The pathological examination of the surgical specimen showed some characteristic changes of syphilitic aortitis. PMID:24492165

  9. 21. VIEW FROM INTERIOR OF 2ND FLOOR ARCHED WINDOW WITH ...

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

    21. VIEW FROM INTERIOR OF 2ND FLOOR ARCHED WINDOW WITH HOLLOW STEEL SASH AND POLISHED PLATE WIRE GLASS. THIS WINDOW IS AT THE FRONT OF THE BUILDING. - Pacific Telephone & Telegraph Company Building, 1519 Franklin Street, Oakland, Alameda County, CA

  10. Complete fourth metatarsal and arches in the foot of Australopithecus afarensis.

    PubMed

    Ward, Carol V; Kimbel, William H; Johanson, Donald C

    2011-02-11

    The transition to full-time terrestrial bipedality is a hallmark of human evolution. A key correlate of human bipedalism is the development of longitudinal and transverse arches of the foot that provide a rigid propulsive lever and critical shock absorption during striding bipedal gait. Evidence for arches in the earliest well-known Australopithecus species, A. afarensis, has long been debated. A complete fourth metatarsal of A. afarensis was recently discovered at Hadar, Ethiopia. It exhibits torsion of the head relative to the base, a direct correlate of a transverse arch in humans. The orientation of the proximal and distal ends of the bone reflects a longitudinal arch. Further, the deep, flat base and tarsal facets imply that its midfoot had no ape-like midtarsal break. These features show that the A. afarensis foot was functionally like that of modern humans and support the hypothesis that this species was a committed terrestrial biped. PMID:21311018

  11. Complex Cervical Aortic Arch With Hypoplasia: A Simple Solution to a Complex Problem.

    PubMed

    Rajbanshi, Bijoy G; Gautam, Navin C; Pradhan, Sidhartha; Sharma, Apurb; Ghimire, Ram K; Joyce, Lyle D

    2016-07-01

    We report a rare case of a 6-year-old boy with a complex right-sided cervical aortic arch, with retroesophageal hypoplastic transverse arch, left subclavian artery arising from the Kommerell diverticulum of the descending aorta, and a vascular ring formed by the ductus ligament. An extraanatomic ascending-to-descending aorta bypass was done through a median sternotomy along with division of the ductus ligament, without any complications and good results. PMID:27343523

  12. Aortic Arch Aneurysms: Treatment with Extra anatomical Bypass and Endovascular Stent-Grafting

    SciTech Connect

    Kato, Noriyuki; Shimono, Takatsugu; Hirano, Tadanori; Mizumoto, Toru; Ishida, Masaki; Fujii, Hideki; Yada, Isao; Takeda, Kan

    2002-10-15

    Endovascular repair of thoracic aortic aneurysms is emerging as an attractive alternative to surgical graft replacement. However,patients with aortic arch aneurysms are often excluded from the target of endovascular repair because of lack of suitable landing zones, especially at the proximal ones. In this paper we describe our method for treating patients with aortic arch aneurysms using a combination of extra anatomical bypass surgery and endovascular stent-grafting.

  13. In vivo Study of the Accuracy of Dual-arch Impressions

    PubMed Central

    de Lima, Luciana Martinelli Santayana; Borges, Gilberto Antonio; Junior, Luiz Henrique Burnett; Spohr, Ana Maria

    2014-01-01

    Background: This study evaluated in vivo the accuracy of metal (Smart®) and plastic (Triple Tray®) dual-arch trays used with vinyl polysiloxane (Flexitime®), in the putty/wash viscosity, as well as polyether (Impregum Soft®) in the regular viscosity. Materials and Methods: In one patient, an implant-level transfer was screwed on an implant in the mandibular right first molar, serving as a pattern. Ten impressions were made with each tray and impression material. The impressions were poured with Type IV gypsum. The width and height of the pattern and casts were measured in a profile projector (Nikon). The results were submitted to Student’s t-test for one sample (α = 0.05). Results: For the width distance, the plastic dual-arch trays with vinyl polysiloxane (4.513 mm) and with polyether (4.531 mm) were statistically wider than the pattern (4.489 mm). The metal dual-arch tray with vinyl polysiloxane (4.504 mm) and with polyether (4.500 mm) did not differ statistically from the pattern. For the height distance, only the metal dual-arch tray with polyether (2.253 mm) differed statistically from the pattern (2.310 mm). Conclusion: The metal dual-arch tray with vinyl polysiloxane, in the putty/wash viscosities, reproduced casts with less distortion in comparison with the same technique with the plastic dual-arch tray. The plastic or metal dual-arch trays with polyether reproduced cast with greater distortion. How to cite the article: Santayana de Lima LM, Borges GA, Burnett LH Jr, Spohr AM. In vivo study of the accuracy of dual-arch impressions. J Int Oral Health 2014;6(3):50-5. PMID:25083032

  14. Photogeology: Part S: mare ridges and arches in southern Oceanus Procellarum

    USGS Publications Warehouse

    Colton, George W.; Howard, Keith A.; Moore, Henry J.

    1972-01-01

    Low-relief mare features such as ridges and arches are best studied by using stereoscopic photographs taken at low Sun angles. Apollo 16 metric camera photography of the southern Oceanus Procellarum east of Letronne Crater reveals a diversity of subtle features (fig. 29-125) and adds significantly to an understanding of the forms of mare ridges and arches their relative ages, and their association with fractures and sinuous rilles.

  15. Resection of the Aortic Arch with Moderate Hypothermia and Temporary Circulatory Arrest

    PubMed Central

    Speir, Alan M.; Grey, Douglas P.; Cooley, Denton A.

    1982-01-01

    Resection of the aortic arch with the use of moderate hypothermia and temporary circulatory arrest was performed in a 63-year-old woman. The simplified technique is described, along with a brief review of the literature. The patient recovered uneventfully. After this manuscript was prepared, two other patients underwent successful replacement of the aortic arch for aneurysm. These cases are also summarized briefly in an illustrated table. PMID:15226933

  16. Closed injury of the aortic arch and subsequent formation of a false aneurysm.

    PubMed

    Janevski, B

    1983-01-01

    The case history of a 25-year-old man who sustained a blunt trauma to the chest in a car accident and developed a false aneurysm of the aortic isthmus is reported. The injury of the aortic arch was not initially recognized. The diagnosis was established on the chest X-rays and arteriograms obtained 1 year after the trauma. The clinical and radiological signs of closed injuries of the aortic arch are reviewed. PMID:6617430

  17. Integrated Design and Production Reference Integration with ArchGenXML V1.00

    SciTech Connect

    Barter, R H

    2004-07-20

    ArchGenXML is a tool that allows easy creation of Zope products through the use of Archetypes. The Integrated Design and Production Reference (IDPR) should be highly configurable in order to meet the needs of a diverse engineering community. Ease of configuration is key to the success of IDPR. The purpose of this paper is to describe a method of using a UML diagram editor to configure IDPR through ArchGenXML and Archetypes.

  18. Arch to Descending Aorta Extra-anatomic Aortic Repair for Thoracic Stent Graft Infection.

    PubMed

    Gagné-Loranger, Maude; Dumont, Éric; Voisine, Pierre; Mohammadi, Siamak; Dagenais, François

    2016-01-01

    We report a case of a pedunculated mass of the aortic isthmus. The patient was treated with bilateral carotid-subclavian bypass and a stent graft to cover the thrombus within the distal arch. The postoperative course was complicated by a stent graft infection. The patient underwent graft explantation with aortic continuity using extra-anatomic bypass from the aortic arch to the distal descending aorta. PMID:26481087

  19. Helical axis stellarator equilibrium model

    SciTech Connect

    Koniges, A.E.; Johnson, J.L.

    1985-02-01

    An asymptotic model is developed to study MHD equilibria in toroidal systems with a helical magnetic axis. Using a characteristic coordinate system based on the vacuum field lines, the equilibrium problem is reduced to a two-dimensional generalized partial differential equation of the Grad-Shafranov type. A stellarator-expansion free-boundary equilibrium code is modified to solve the helical-axis equations. The expansion model is used to predict the equilibrium properties of Asperators NP-3 and NP-4. Numerically determined flux surfaces, magnetic well, transform, and shear are presented. The equilibria show a toroidal Shafranov shift.

  20. Understanding thermal equilibrium through activities

    NASA Astrophysics Data System (ADS)

    Pathare, Shirish; Huli, Saurabhee; Nachane, Madhura; Ladage, Savita; Pradhan, Hemachandra

    2015-03-01

    Thermal equilibrium is a basic concept in thermodynamics. In India, this concept is generally introduced at the first year of undergraduate education in physics and chemistry. In our earlier studies (Pathare and Pradhan 2011 Proc. episteme-4 Int. Conf. to Review Research on Science Technology and Mathematics Education pp 169-72) we found that students in India have a rather unsatisfactory understanding of thermal equilibrium. We have designed and developed a module of five activities, which are presented in succession to the students. These activities address the students’ alternative conceptions that underlie their lack of understanding of thermal equilibrium and aim at enhancing their understanding of the concept.

  1. An Arched Micro-Injector (ARCMI) for Innocuous Subretinal Injection

    PubMed Central

    Li, Chengguo; Lee, Sung Ho; Kim, Kibom; Jung, Hyungil

    2014-01-01

    Several critical ocular diseases that can lead to blindness are due to retinal disorders. Subretinal drug delivery has been developed recently for the treatment of retinal disorders such as hemorrhage because of the specific ocular structure, namely, the blood retinal barrier (BRB). In the present study, we developed an Arched Micro-injector (ARCMI) for subretinal drug delivery with minimal retinal tissue damage. ARCMIs were fabricated using three major techniques: reverse drawing lithography, controlled air flow, and electroplating. In order to achieve minimal retinal tissue damage, ARCMIs were fabricated with specific features such as a 0.15 mm−1 curvature, 45° tip bevel, 5 mm length, inner diameter of 40 µm, and an outer diameter of 100 µm. These specific features were optimized via in-vitro experiments in artificial ocular hemispherical structures and subretinal injection of indocyanine green in porcine eye ex-vivo. We confirmed that the ARCMI was capable of delivering ocular drugs by subretinal injection without unusual subretinal tissue damage, including hemorrhage. PMID:25111562

  2. SOFIA/FORCAST Observations of the Arched Filamentary Region in the Galactic Center

    NASA Astrophysics Data System (ADS)

    Hankins, Matthew; Lau, Ryan M.; Morris, Mark; Herter, Terry L.

    2016-06-01

    Abstract: We present 19.7, 25.2, 31.5, and 37.1 μm maps of the Thermal Arched Filament region in the Galactic Center taken with the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) with an angular resolution of 3.2-3.8". We calculate the integrated infrared luminosity of the Arched Filaments and show that they are consistent with being heated by the nearby Arches cluster. Additionally, using our observations, we infer dust temperatures (75 – 90 K) across the Arched Filaments which are remarkably consistent over large spatial scales (∼ 25 pc). We discuss the possible geometric effects needed to recreate this temperature structure. Additionally, we compare the observed morphology of the Arches in the FORCAST maps with the Paschen-α emission in the region to study what fraction of the infrared emission may be coming from dust in the HII region versus the PDR beneath it. Finally, we use Spitzer/IRAC 8 μm data to look for spatial variations in PAH abundance in the rich UV environment of the young (~2-4 Myr) and massive Arches cluster.

  3. Stratigraphic variations in the Carboniferous section across the Arkansas-Oklahoma State Line Arch

    NASA Astrophysics Data System (ADS)

    Engelhardt, Tyler D.

    The State Line Arch is represented by a structural high that trends through the study area in a loose alignment with the Arkansas-Oklahoma state line. Evidence of the arch extending further to the north includes a structural high and stratigraphic variation at an outcrop on Highway 59 near Evansville Mountain in Crawford County, Arkansas. The exact timing of the formation of the arch remains undetermined, but upper Devonian thinning at the top of the arch indicates the structure is pre-Mississippian. The reason for the development of the arch is poorly understood, but evidence linking Mississippian-aged Waulsortian mounds to Precambrian Spavinaw granite structures of northeastern Oklahoma and southwestern Missouri suggests Precambrian basement structures may extend into the study area. The structural nature of the arch provided an environment favorable to carbonate build-up during deposition of the Mississippian interval. A previously unidentified limestone unit measuring 175 feet thick likely represents the transgressive phase of a transgressive-regressive sequence responsible for the deposition of the Mayes Group of northeastern Oklahoma. Growth on the downthrown side of the Muldrow-Mulberry Fault system may indicate earlier movement than previous studies have suggested on the east-west trending normal faults of the Arkoma Basin. A possible roll-over anticline structure may exist to the south of the Muldrow-Mulberry fault system.

  4. Developmental evidence for serial homology of the vertebrate jaw and gill arch skeleton

    PubMed Central

    Gillis, J. Andrew; Modrell, Melinda S.; Baker, Clare V. H.

    2013-01-01

    Gegenbaur’s classical hypothesis of jaw-gill arch serial homology is widely cited, but remains unsupported by either paleontological evidence (e.g. a series of fossils reflecting the stepwise transformation of a gill arch into a jaw) or developmental genetic data (e.g. shared molecular mechanisms underlying segment identity in the mandibular, hyoid and gill arch endoskeletons). Here we show that nested expression of Dlx genes – the “Dlx code” that specifies upper and lower jaw identity in mammals and teleosts – is a primitive feature of the mandibular, hyoid and gill arches of jawed vertebrates. Using fate-mapping techniques, we demonstrate that the principal dorsal and ventral endoskeletal segments of the jaw, hyoid and gill arches of the skate Leucoraja erinacea derive from molecularly equivalent mesenchymal domains of combinatorial Dlx gene expression. Our data suggest that vertebrate jaw, hyoid and gill arch cartilages are serially homologous, and were primitively patterned dorsoventrally by a common Dlx blueprint. PMID:23385581

  5. The branchial arches and HGF are growth-promoting and chemoattractant for cranial motor axons.

    PubMed

    Caton, A; Hacker, A; Naeem, A; Livet, J; Maina, F; Bladt, F; Klein, R; Birchmeier, C; Guthrie, S

    2000-04-01

    During development, cranial motor neurons extend their axons along distinct pathways into the periphery. For example, branchiomotor axons extend dorsally to leave the hindbrain via large dorsal exit points. They then grow in association with sensory ganglia, to their targets, the muscles of the branchial arches. We have investigated the possibility that pathway tissues might secrete diffusible chemorepellents or chemoattractants that guide cranial motor axons, using co-cultures in collagen gels. We found that explants of dorsal neural tube or hindbrain roof plate chemorepelled cranial motor axons, while explants of cranial sensory ganglia were weakly chemoattractive. Explants of branchial arch mesenchyme were strongly growth-promoting and chemoattractive for cranial motor axons. Enhanced and oriented axon outgrowth was also elicited by beads loaded with Hepatocyte Growth Factor (HGF); antibodies to this protein largely blocked the outgrowth and orientation effects of the branchial arch on motor axons. HGF was expressed in the branchial arches, whilst Met, which encodes an HGF receptor, was expressed by subpopulations of cranial motor neurons. Mice with targetted disruptions of HGF or Met showed defects in the navigation of hypoglossal motor axons into the branchial region. Branchial arch tissue may thus act as a target-derived factor that guides motor axons during development. This influence is likely to be mediated partly by Hepatocyte Growth Factor, although a component of branchial arch-mediated growth promotion and chemoattraction was not blocked by anti-HGF antibodies. PMID:10725250

  6. Carpal arch and median nerve changes during radioulnar wrist compression in carpal tunnel syndrome patients

    PubMed Central

    Marquardt, Tamara L.; Evans, Peter J.; Seitz, William H.; Li, Zong-Ming

    2015-01-01

    The purpose of this study was to investigate the morphological changes of the carpal arch and median nerve during the application of radiounlarly directed compressive force across the wrist in patients with carpal tunnel syndrome. Radioulnar compressive forces of 10 N and 20 N were applied at the distal level of the carpal tunnel in 10 female patients diagnosed with carpal tunnel syndrome. Immediately prior to force application and after 3 minutes of application, ultrasound images of the distal carpal tunnel were obtained. It was found that applying force across the wrist decreased the carpal arch width (p < 0.001) and resulted in increased carpal arch height (p < 0.01), increased carpal arch curvature (p < 0.001), and increased radial distribution of the carpal arch area (p < 0.05). It was also shown that wrist compression reduced the flattening of the median nerve, as indicated by changes in the nerve’s circularity and flattening ratio (p < 0.001). Statement of clinical significance This study demonstrated that the carpal arch can be non-invasively augmented by applying compressive force across the wrist, and that this strategy may decompress the median nerve providing symptom relief to patients with carpal tunnel syndrome. PMID:26662276

  7. Analysis of an arched outer-race ball bearing considering centrifugal forces

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Anderson, W. J.

    1972-01-01

    A Newton-Raphson method of iteration was used in evaluating the radial and axial projection of the distance between the ball center and the outer raceway groove curvature center (V and W). Fatigue life evaluations were made. The similar analysis of a conventional bearing can be directly obtained from the arched bearing analysis by simply letting the amount of arching be zero (g = 0) and not considering equations related to the unloaded half of the outer race. The analysis was applied to a 150-mm angular contact ball bearing. Results for life, contact loads, and angles are shown for a conventional bearing (g = 0) and two arched bearings (g = 0.127 mm (0.005 in.), and 0.254 mm (0.010 in.)). The results indicate that an arched bearing is highly desirable for high speed applications. In particular, for a DN value of 3 million (20,000 rpm) and an applied axial load of 4448 N (1000 lb), an arched bearing shows an improvement in life of 306 percent over that of a conventional bearing. At 4.2 million DN (28,000 rpm), the corresponding improvement is 340 percent. It was also found for low speeds, the arched bearing does not offer the advantages that it does for high speed applications.

  8. Rearfoot posture of Australopithecus sediba and the evolution of the hominin longitudinal arch

    PubMed Central

    Prang, Thomas C.

    2015-01-01

    The longitudinal arch is one of the hallmarks of the human foot but its evolutionary history remains controversial due to the fragmentary nature of the fossil record. In modern humans, the presence of a longitudinal arch is reflected in the angular relationships among the major surfaces of the human talus and calcaneus complex, which is also known as the rearfoot. A complete talus and calcaneus of Australopithecus sediba provide the opportunity to evaluate rearfoot posture in an early hominin for the first time. Here I show that A. sediba is indistinguishable from extant African apes in the angular configuration of its rearfoot, which strongly suggests that it lacked a longitudinal arch. Inferences made from isolated fossils support the hypothesis that Australopithecus afarensis possessed an arched foot. However, tali attributed to temporally younger taxa like Australopithecus africanus and Homo floresiensis are more similar to those of A. sediba. The inferred absence of a longitudinal arch in A. sediba would be biomechanically consistent with prior suggestions of increased midtarsal mobility in this taxon. The morphological patterns in talus and calcaneus angular relationships among fossil hominins suggest that there was diversity in traits associated with the longitudinal arch in the Plio-Pleistocene. PMID:26628197

  9. Wave motion analysis in arch structures via wavelet finite element method

    NASA Astrophysics Data System (ADS)

    Yang, Zhibo; Chen, Xuefeng; Li, Xiang; Jiang, Yongying; Miao, Huihui; He, Zhengjia

    2014-01-01

    The application of B-spline wavelet on interval (BSWI) finite element method for wave motion analysis in arch structures is presented in this paper. Instead of traditional polynomial interpolation, scaling functions at certain scales have been adopted to form the shape functions and construct wavelet-based elements. Different from other wavelet numerical methods adding wavelets directly, the element displacement field represented by the coefficients of wavelets expansions is transformed from wavelet space to physical space via the corresponding transformation matrix. The energy functional of the arch is obtained by the generalized shell theory, and the finite element model for wave motion analysis is constructed according to Hamilton's principle and the central difference method in time domain. Taking the practical application into account, damaged arch waveguides are also investigated. Proper analysis of the responses from structure damages allows one to indicate the location very precisely. This paper mainly focuses on the crack in structures. Based on Castigliano's theorem and the Pairs equation, the local flexibility of crack is formulated for BSWI element. Numerical experiments are performed to study the effect of wave propagations in arch waveguides, that is, frequency dispersion and mode spilt in the arch. The responses of the arch with cracks are simulated under the broad-band, narrow-band and chirp excitations. In order to estimate the spatial, time and frequency concentrations of responses, the reciprocal length, time-frequency transform and correlation coefficient are introduced in this investigation.

  10. Carpal arch and median nerve changes during radioulnar wrist compression in carpal tunnel syndrome patients.

    PubMed

    Marquardt, Tamara L; Evans, Peter J; Seitz, William H; Li, Zong-Ming

    2016-07-01

    The purpose of this study was to investigate the morphological changes of the carpal arch and median nerve during the application of radiounlarly directed compressive force across the wrist in patients with carpal tunnel syndrome. Radioulnar compressive forces of 10 N and 20 N were applied at the distal level of the carpal tunnel in 10 female patients diagnosed with carpal tunnel syndrome. Immediately prior to force application and after 3 min of application, ultrasound images of the distal carpal tunnel were obtained. It was found that applying force across the wrist decreased the carpal arch width (p < 0.001) and resulted in increased carpal arch height (p < 0.01), increased carpal arch curvature (p < 0.001), and increased radial distribution of the carpal arch area (p < 0.05). It was also shown that wrist compression reduced the flattening of the median nerve, as indicated by changes in the nerve's circularity and flattening ratio (p < 0.001). This study demonstrated that the carpal arch can be non-invasively augmented by applying compressive force across the wrist, and that this strategy may decompress the median nerve providing symptom relief to patients with carpal tunnel syndrome. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1234-1240, 2016. PMID:26662276

  11. Correlation between maxillary central incisor crown morphology and mandibular dental arch form in normal occlusion subjects.

    PubMed

    Paranhos, Luiz Renato; Lima, Carolina Souto; da Silva, Ricardo Henrique Alves; Daruge Júnior, Eduardo; Torres, Fernando Cesar

    2012-01-01

    The aim of this study was to evaluate the correlation between the morphology of the mandibular dental arch and the maxillary central incisor crown. Cast models from 51 Caucasian individuals, older than 15 years, with optimal occlusion, no previous orthodontic treatment, featuring 4 of the 6 keys to normal occlusion by Andrews (the first being mandatory) were observed. The models were digitalized using a 3D scanner, and images of the maxillary central incisor and mandibular dental arch were obtained. These were printed and placed in an album below pre-set models of arches and dental crowns, and distributed to 12 dental surgeons, who were asked to choose which shape was most in accordance with the models and crown presented. The Kappa test was performed to evaluate the concordance among evaluators while the chi-square test was used to verify the association between the dental arch and central incisor morphology, at a 5% significance level. The Kappa test showed moderate agreement among evaluators for both variables of this study, and the chi-square test showed no significant association between tooth shape and mandibular dental arch morphology. It may be concluded that the use of arch morphology as a diagnostic method to determine the shape of the maxillary central incisor is not appropriate. Further research is necessary to assess tooth shape using a stricter scientific basis. PMID:22666773

  12. Reappraisal of the removable partial denture as a treatment option for the shortened dental arch.

    PubMed

    Nassani, Mohammad Zakaria; Tarakji, Bassel; Baroudi, Kusai; Sakka, Salah

    2013-04-01

    For patients with shortened dental arches, many treatment options are available. The existing situation can be maintained by stabilizing the present dentition and improving the occlusion without extending the arch. Alternatively, the shortened dental arch can be extended by either a free-end saddle removable partial denture, cantilevered fixed bridge, or by an implant-supported prosthesis. The free-end saddle removable partial denture can be considered a simple, non-invasive, and relatively cheap treatment option for the shortened dental arch. It was believed that such prosthodontic rehabilitation would be beneficial for the patients in terms of improving oral functions. However, the existing literature indicates that the prognosis of free-end saddle removable partial denture is not predictable, it is problematic, and its contribution to oral functions in patients with shortened dental arches is considered to be dubious. This paper reviews and summarizes the current literature about the outcome of extending the shortened dental arch by a free-end saddle removable partial denture. It also outlines factors that may affect the prognosis of this prosthetic treatment. PMID:24883037

  13. Analysis of the pedestrian arching at bottleneck based on a bypassing behavior model

    NASA Astrophysics Data System (ADS)

    Tang, Ming; Jia, Hongfei; Ran, Bin; Li, Jun

    2016-07-01

    A bypassing behavior model was proposed, in which the local optimal decision behavior in the strategy level was modeled in velocity-time domain, to describe how pedestrians bypass the local obstacles considering the relative speed. The model contains (1) pedestrian visual and contact information acquisition; (2) motion state prediction of the local obstacles based on the visual and contact information; (3) pedestrian bypass strategy modeling in the velocity-time domain; (4) moving and overlapping solution. In the numerical solution, velocity domain was divided into n equal angle, the value of n ranges from 2 to infinity, the Manhattan space was refined gradually to Euclid Space accordingly, in which the movement of pedestrians was described. The model was applied to the analysis of pedestrian arching at the bottleneck in the emergent evacuation situation. (1) The results showed that the formation of the pedestrian arching at the bottleneck was deformation pressure, because many pedestrians try to pass through the bottleneck simultaneously, even in the absence of friction, the pedestrian arching still occurs; (2) In the emergent situation, we are more concerned about the bottleneck attribution of resistance to form the arching, the calculation and simulation results showed that the probability of an arching and the bottleneck width is an exponential function relationship, so when the stampede occurs in the middle of the bottleneck, the probability of arching will increase exponentially.

  14. Gender identification and morphologic classification of tooth, arch and palatal forms in Saudi population

    PubMed Central

    Mohammad, Aljanakh; Koralakunte, Pavankumar Ravi

    2015-01-01

    Aims: To determine various tooth form, arch form, and palatal form with gender identification between males and females of the Saudi population. Materials and Methods: Irreversible hydrocolloid impressions were made of the maxillary teeth of 100 dentate male and female subjects to obtain study casts. A standardized procedure was adopted to photograph the maxillary dental arches and the maxillary central incisors on the study casts taken from each subject. The outline form of tooth, arch, and palatal form were determined using a standardized method. The average of six prosthodontist's evaluation was considered who classified the outline tracings visually. The statistical analysis was performed using Chi-Square and results tabulated. Results: The predominant tooth is combination form in males and ovoid form in females, the predominant arch is ovoid form in males and square form in females and the predominant palatal form are both U and V shaped in males and U-shaped in females. Conclusion: Except for the tooth form there was a significant difference with arch and palatal form among males and females of the population group studied. The determined tooth, arch and palatal forms are useful in selection and arrangement of artificial teeth among Saudi edentulous population group. Generalizing from the study is questionable as the sample size is small. Further studies should be conducted in a larger sample to confirm the study results PMID:26538903

  15. The role of the endoderm in the development and evolution of the pharyngeal arches

    PubMed Central

    Graham, Anthony; Okabe, Masataka; Quinlan, Robyn

    2005-01-01

    The oro-pharyngeal apparatus has its origin in a series of bulges found on the lateral surface of the embryonic head, the pharyngeal arches. Significantly, the development of these structures is extremely complex, involving interactions between a number of disparate embryonic cell types: ectoderm, endoderm, mesoderm and neural crest, each of which generates particular components of the arches, and whose development must be co-ordinated to generate the functional adult oro-pharyngeal apparatus. In the past most studies have emphasized the role played by the neural crest, which generates the skeletal elements of the arches, in directing pharyngeal arch development. However, it is now apparent that the pharyngeal endoderm plays an important role in directing arch development. Here we discuss the role of the pharyngeal endoderm in organizing the development of the pharyngeal arches, and the mechanisms that act to pattern the endoderm itself and those which direct its morphogenesis. Finally, we discuss the importance of modification to the pharyngeal endoderm during vertebrate evolution. In particular, we focus on the emergence of the parathyroid gland, which we have recently shown to be the result of the internalization of the gills. PMID:16313389

  16. Triggers for the Collapse of Ice Shelves in Antarctica: Investigating Compressive Arch Failure with Numerical Models

    NASA Astrophysics Data System (ADS)

    Huth, A.; Smith, B. E.

    2015-12-01

    Antarctic ice shelves restrain, or buttress, grounded ice from flowing freely into the ocean by redistributing the force of the ice flow to pinning points (ice rises) at the ice front and shear margins at adjacent bay walls. This buttressing process typically defines a 'compressive arch' in the strain rate-field of the ice shelf, where the smallest principal component transitions from compressive inland of the arch to extensive seaward of the arch. If the compressive arch is breached due to iceberg calving at the ice front or thinning at the shear margins, the ice shelf will retreat irreversibly to a new stable configuration or collapse entirely. This retreat can compromise ice shelf buttressing, resulting in sea-level rise and ocean freshening as grounded ice flows unrestricted into the ocean. Here, we investigate the dynamics of compressive arch failure using Larsen C ice shelf as a test case for a larger study that will include several other ice shelves and projections for sea-level rise. We use satellite observations to develop a steady state model of Larsen C in Elmer/ICE, a finite element ice sheet/ice flow software package. We run calving and thinning simulations to determine the conditions needed to trigger ice shelf retreat via compressive arch failure and discuss the likelihood of these scenarios occurring in relation to extrapolations of current melt profiles and calving trends.

  17. Rearfoot posture of Australopithecus sediba and the evolution of the hominin longitudinal arch.

    PubMed

    Prang, Thomas C

    2015-01-01

    The longitudinal arch is one of the hallmarks of the human foot but its evolutionary history remains controversial due to the fragmentary nature of the fossil record. In modern humans, the presence of a longitudinal arch is reflected in the angular relationships among the major surfaces of the human talus and calcaneus complex, which is also known as the rearfoot. A complete talus and calcaneus of Australopithecus sediba provide the opportunity to evaluate rearfoot posture in an early hominin for the first time. Here I show that A. sediba is indistinguishable from extant African apes in the angular configuration of its rearfoot, which strongly suggests that it lacked a longitudinal arch. Inferences made from isolated fossils support the hypothesis that Australopithecus afarensis possessed an arched foot. However, tali attributed to temporally younger taxa like Australopithecus africanus and Homo floresiensis are more similar to those of A. sediba. The inferred absence of a longitudinal arch in A. sediba would be biomechanically consistent with prior suggestions of increased midtarsal mobility in this taxon. The morphological patterns in talus and calcaneus angular relationships among fossil hominins suggest that there was diversity in traits associated with the longitudinal arch in the Plio-Pleistocene. PMID:26628197

  18. Long-term stability of dental arch form in normal occlusion from 13 to 31 years of age.

    PubMed

    Henrikson, J; Persson, M; Thilander, B

    2001-02-01

    Based on observations of longitudinal changes in dental arch dimensions, it has been stated that an individuality of arch form and an integrity of this form exists. However, longitudinal studies evaluating arch form changes have rarely been reported in the literature. The purpose of this investigation was to use a computer-assisted method for the description and analysis of maxillary and mandibular arch form in a sample of normal occlusion subjects, and to evaluate the long-term stability in dental arch form from the age of 13-31 years. The study was carried out on 30 subjects of Scandinavian origin with normal occlusion, recorded at a mean age of 13.6 years and at follow-up at 31.1 years. Arch form analysis was based on a standardized photographic procedure, digitization of morphological landmarks, and a computerized form analysis in which arch form was described using eccentricity values of conics. No specific arch form could be found to represent the sample. Age changes occurred in arch form, although with large individual variations. For the mandible, a significant change to a more rounded arch form with age was found, which in males was accompanied by a significant increase in inter-molar distance and reduction in arch depth. There was also a significant correlation between change in mandibular arch form and increased irregularity of the lower incisors. These findings of lack of stability in arch form in normal occlusion subjects, when passing from adolescence into adulthood, further question the possibility of achieving stability post-orthodontically. PMID:11296510

  19. Equilibrium and Orientation in Cephalopods.

    ERIC Educational Resources Information Center

    Budelmann, Bernd-Ulrich

    1980-01-01

    Describes the structure of the equilibrium receptor system in cephalopods, comparing it to the vertebrate counterpart--the vestibular system. Relates the evolution of this complex system to the competition of cephalopods with fishes. (CS)

  20. Equilibrium Constants You Can Smell.

    ERIC Educational Resources Information Center

    Anderson, Michael; Buckley, Amy

    1996-01-01

    Presents a simple experiment involving the sense of smell that students can accomplish during a lecture. Illustrates the important concepts of equilibrium along with the acid/base properties of various ions. (JRH)

  1. Equilibrium ignition for ICF capsules

    SciTech Connect

    Lackner, K.S.; Colgate, S.A.; Johnson, N.L.; Kirkpatrick, R.C.; Menikoff, R.; Petschek, A.G.

    1993-12-31

    There are two fundamentally different approaches to igniting DT fuel in an ICF capsule which can be described as equilibrium and hot spot ignition. In both cases, a capsule which can be thought of as a pusher containing the DT fuel is imploded until the fuel reaches ignition conditions. In comparing high-gain ICF targets using cryogenic DT for a pusher with equilibrium ignition targets using high-Z pushers which contain the radiation. The authors point to the intrinsic advantages of the latter. Equilibrium or volume ignition sacrifices high gain for lower losses, lower ignition temperature, lower implosion velocity and lower sensitivity of the more robust capsule to small fluctuations and asymmetries in the drive system. The reduction in gain is about a factor of 2.5, which is small enough to make the more robust equilibrium ignition an attractive alternative.

  2. Edge equilibrium code for tokamaks

    SciTech Connect

    Li, Xujing; Drozdov, Vladimir V.

    2014-01-15

    The edge equilibrium code (EEC) described in this paper is developed for simulations of the near edge plasma using the finite element method. It solves the Grad-Shafranov equation in toroidal coordinate and uses adaptive grids aligned with magnetic field lines. Hermite finite elements are chosen for the numerical scheme. A fast Newton scheme which is the same as implemented in the equilibrium and stability code (ESC) is applied here to adjust the grids.

  3. A search for equilibrium states

    NASA Technical Reports Server (NTRS)

    Zeleznik, F. J.

    1982-01-01

    An efficient search algorithm is described for the location of equilibrium states in a search set of states which differ from one another only by the choice of pure phases. The algorithm has three important characteristics: (1) it ignores states which have little prospect for being an improved approximation to the true equilibrium state; (2) it avoids states which lead to singular iteration equations; (3) it furnishes a search history which can provide clues to alternative search paths.

  4. Selective cerebro-myocardial perfusion in complex congenital aortic arch pathology: a novel technique.

    PubMed

    De Rita, Fabrizio; Lucchese, Gianluca; Barozzi, Luca; Menon, Tiziano; Faggian, Giuseppe; Mazzucco, Alessandro; Luciani, Giovanni Battista

    2011-11-01

    Simultaneous cerebro-myocardial perfusion has been described in neonatal and infant arch surgery, suggesting a reduction in cardiac morbidity. Here reported is a novel technique for selective cerebral perfusion combined with controlled and independent myocardial perfusion during surgery for complex or recurrent aortic arch lesions. From April 2008 to April 2011, 10 patients with arch pathology underwent surgery (two hypoplastic left heart syndrome [HLHS], four recurrent arch obstruction, two aortic arch hypoplasia + ventricular septal defect [VSD], one single ventricle + transposition of the great arteries + arch hypoplasia, one interrupted aortic arch type B + VSD). Median age was 63 days (6 days-36 years) and median weight 4.0 kg (1.6-52). Via midline sternotomy, an arterial cannula (6 or 8 Fr for infants) was directly inserted into the innominate artery or through a polytetrafluoroethylene (PTFE) graft (for neonates <2.0 kg). A cardioplegia delivery system was inserted into the aortic root. Under moderate hypothermia, ascending and descending aorta were cross-clamped, and "beating heart and brain" aortic arch repair was performed. Arch repair was composed of patch augmentation in five, end-to-side anastomosis in three, and replacement in two patients. Average cardiopulmonary bypass time was 163 ± 68 min (71-310). In two patients only (one HLHS, one complex single ventricle), a period of cardiac arrest was required to complete intracardiac repair. In such cases, antegrade blood cardioplegia was delivered directly via the same catheter used for selective myocardial perfusion. Average time of splanchnic ischemia during cerebro-myocardial perfusion was 39 ± 18 min (17-69). Weaning from cardiopulmonary bypass was achieved without inotropic support in three and with low dose in seven patients. One patient required veno-arterial extracorporeal membrane oxygenation. Four patients, body weight <3.0 kg, needed delayed sternal closure. No neurologic dysfunction was noted

  5. Shape characteristics of equilibrium and non-equilibrium fractal clusters

    NASA Astrophysics Data System (ADS)

    Mansfield, Marc L.; Douglas, Jack F.

    2013-07-01

    It is often difficult in practice to discriminate between equilibrium and non-equilibrium nanoparticle or colloidal-particle clusters that form through aggregation in gas or solution phases. Scattering studies often permit the determination of an apparent fractal dimension, but both equilibrium and non-equilibrium clusters in three dimensions frequently have fractal dimensions near 2, so that it is often not possible to discriminate on the basis of this geometrical property. A survey of the anisotropy of a wide variety of polymeric structures (linear and ring random and self-avoiding random walks, percolation clusters, lattice animals, diffusion-limited aggregates, and Eden clusters) based on the principal components of both the radius of gyration and electric polarizability tensor indicates, perhaps counter-intuitively, that self-similar equilibrium clusters tend to be intrinsically anisotropic at all sizes, while non-equilibrium processes such as diffusion-limited aggregation or Eden growth tend to be isotropic in the large-mass limit, providing a potential means of discriminating these clusters experimentally if anisotropy could be determined along with the fractal dimension. Equilibrium polymer structures, such as flexible polymer chains, are normally self-similar due to the existence of only a single relevant length scale, and are thus anisotropic at all length scales, while non-equilibrium polymer structures that grow irreversibly in time eventually become isotropic if there is no difference in the average growth rates in different directions. There is apparently no proof of these general trends and little theoretical insight into what controls the universal anisotropy in equilibrium polymer structures of various kinds. This is an obvious topic of theoretical investigation, as well as a matter of practical interest. To address this general problem, we consider two experimentally accessible ratios, one between the hydrodynamic and gyration radii, the other

  6. Shape characteristics of equilibrium and non-equilibrium fractal clusters.

    PubMed

    Mansfield, Marc L; Douglas, Jack F

    2013-07-28

    It is often difficult in practice to discriminate between equilibrium and non-equilibrium nanoparticle or colloidal-particle clusters that form through aggregation in gas or solution phases. Scattering studies often permit the determination of an apparent fractal dimension, but both equilibrium and non-equilibrium clusters in three dimensions frequently have fractal dimensions near 2, so that it is often not possible to discriminate on the basis of this geometrical property. A survey of the anisotropy of a wide variety of polymeric structures (linear and ring random and self-avoiding random walks, percolation clusters, lattice animals, diffusion-limited aggregates, and Eden clusters) based on the principal components of both the radius of gyration and electric polarizability tensor indicates, perhaps counter-intuitively, that self-similar equilibrium clusters tend to be intrinsically anisotropic at all sizes, while non-equilibrium processes such as diffusion-limited aggregation or Eden growth tend to be isotropic in the large-mass limit, providing a potential means of discriminating these clusters experimentally if anisotropy could be determined along with the fractal dimension. Equilibrium polymer structures, such as flexible polymer chains, are normally self-similar due to the existence of only a single relevant length scale, and are thus anisotropic at all length scales, while non-equilibrium polymer structures that grow irreversibly in time eventually become isotropic if there is no difference in the average growth rates in different directions. There is apparently no proof of these general trends and little theoretical insight into what controls the universal anisotropy in equilibrium polymer structures of various kinds. This is an obvious topic of theoretical investigation, as well as a matter of practical interest. To address this general problem, we consider two experimentally accessible ratios, one between the hydrodynamic and gyration radii, the other

  7. [The neuronal organization of the amygdala-visceral reflex arch].

    PubMed

    Baklavadzhian, O G; Avetisian, E A; Bagdasarian, K G; Eganova, V S; Nersesian, L B

    1996-01-01

    The paper summarizes the histomorphic, histochemical, autoradiographic, immune-histochemical and electrophysiological data on the structural-functional organization of the amygdalar complexes. While discussing the problem of neuron organization of the afferent and efferent groups in the amygdala-visceral arch the authors present their data of microelectrophysiological studies of the specific amygdala neuron reactions in response to stimulation of the vagus, ventric, and sciatic nerves, and of the second somatic sensor cortex zone. It was observed that interoceptive impulsation reaching the polysensor neurons of the central, corticomedial, and basolateral groups of the amygdala complex nuclei have no significant qualitative differences. A series of experiments demonstrated that the polysensor convergent amygdala neurons are also polyeffectoral. Comparative studies of the sympathetic discharges in the white connecting branches produced by stimulation of the above nuclear amygdala groups, confirmed absence of a clear topographic localization of the sympatho-activating structures within an amygdala. Comparative exploration of the parasympathetic discharges in the pelvis nerve discovered a discharge of complex configuration in response to simulation of the pelvis nerve nuclei. There was no notable topographic localization of the amygdala parasympathoactivating structures. The system's arterial pressure was studied in response to stimulation of various amygdala structures. Low-frequency stimulation (5 Hertz) of all amygdala structures produces depressor reactions, high-frequency stimulation (100 Hertz) produces pressor reactions. Microelectrophysiological data are provided on the specific reactions of the inspiration and expiration neurons of the bulbar respiratory centre under frequency stimulation of various amygdala structures. The authors have concluded that the bulbar-spinal mechanisms regulating the vegetative functions are implemented by polysensoral

  8. Elephant trunk technique for hybrid aortic arch repair.

    PubMed

    Miyamoto, Yuji

    2014-03-01

    The original elephant trunk technique was developed by Borst in 1983 for the treatment of aortic arch aneurysms. This technique reduced operative risks, but was associated with cumulative mortality rates of 6.9 % for the first stage and 7.5 % for the second stage. Patients also waited a long time between two major surgical procedures. Only 50.4 % of patients underwent the second-stage surgery, and there was a significant interval mortality rate of 10.7 %. With the advent of stent-graft techniques, two different hybrid elephant trunk techniques were developed. One technique is first-stage elephant trunk graft placement followed by second-stage endovascular completion. The conventional elephant trunk graft provides a good landing zone for the stent-graft, and endovascular completion is a useful alternative to conventional second-stage surgery. This method has few major complications, and a postoperative paraplegia rate of 1.1 %. The other technique is the frozen elephant trunk technique. This technique eliminates the need for subsequent endovascular completion, and is particularly useful for the treatment of acute type A dissection because it can achieve a secure seal. However, it is associated with a higher rate of spinal cord ischemia than other methods such as the original elephant trunk technique. The left subclavian artery (LSA) is often lost when performing a hybrid elephant trunk procedure. Revascularization of the LSA should be performed to prevent arm ischemia and neurological complications such as paraplegia or stroke, although the level of evidence for this recommendation is low. PMID:23943042

  9. Role of aortic arch vascular mechanics in cardiovagal baroreflex sensitivity.

    PubMed

    Klassen, Stephen A; Chirico, Daniele; Dempster, Kylie S; Shoemaker, J Kevin; O'Leary, Deborah D

    2016-07-01

    Cardiovagal baroreflex sensitivity (cvBRS) measures the efficiency of the cardiovagal baroreflex to modulate heart rate in response to increases or decreases in systolic blood pressure (SBP). Given that baroreceptors are located in the walls of the carotid sinuses (CS) and aortic arch (AA), the arterial mechanics of these sites are important contributors to cvBRS. However, the relative contribution of CS and AA mechanics to cvBRS remains unclear. This study employed sex differences as a model to test the hypothesis that differences in cvBRS between groups would be explained by the vascular mechanics of the AA but not the CS. Thirty-six young, healthy, normotensive individuals (18 females; 24 ± 2 yr) were recruited. cvBRS was measured using transfer function analysis of the low-frequency region (0.04-0.15 Hz). Ultrasonography was performed at the CS and AA to obtain arterial diameters for the measurement of distensibility. Local pulse pressure (PP) was taken at the CS using a hand-held tonometer, whereas AA PP was estimated using a transfer function of brachial PP. Both cvBRS (25 ± 11 vs. 19 ± 7 ms/mmHg, P = 0.04) and AA distensibility (16.5 ± 6.0 vs. 10.5 ± 3.8 mmHg(-1) × 10(-3), P = 0.02) were greater in females than males. Sex differences in cvBRS were eliminated after controlling for AA distensibility (P = 0.19). There were no sex differences in CS distensibility (5.32 ± 2.3 vs. 4.63 ± 1.3 mmHg(-1) × 10(-3), P = 0.32). The present data demonstrate that AA mechanics are an important contributor to differences in cvBRS. PMID:27122371

  10. Reliability of Arch dams subject to concrete swelling

    SciTech Connect

    Ramos, J.M.; Silva, H.S.; Pinho, S. de

    1995-12-31

    In this report, results of several studies are presented. The main aim of those studies was to assess the reliability of the three arch dams, in which swelling occurred due to alkali- aggregate reactions in various stages of development and having different effects on their reliability: the Cahora-Bassa dam, in Mozambique, where swelling accumulated up to the moment are very moderate and their development is apparently homogeneous; Santa-Luzia dam, in Portugal, where accumulated swelling have already considerable magnitude, nevertheless, important fissuration has not been observed up to the moment due to the homogeneous development of the swelling process; Alto-Ceira dam, also in Portugal, where accumulated swelling have also considerable magnitude but with a heterogeneous development, causing in conjunction with thermal variations important fissuration. Mention is made of mineralogical, chemical and petrographic analyses carried out for identification of the nature of reactions developed in each case and the back-analysis and other technics used in the assessment of the magnitude and distribution of swelling. Results are presented of measurement tests of the ultrasonic pulse velocity, used both in the assessment of alterations in the physical properties of concretes and in the determination of the depth of fissuration. Results are also presented of tests for characterisation of the rheology of integral concrete. Lastly, considerations are made about the reliability of the works on the basis of studies and the results of analyses of the state of stress, performed by means of the finite element method, by assuming for either visco-elastic or visco-elastic-plastic behaviour.

  11. The LaSalle Arch and its effect on Wilcox sequence stratigraphy

    SciTech Connect

    Lawless P.N.; Hart, G.F. )

    1990-09-01

    The LaSalle Arch is a southerly trending anticline separating the Louisiana and Mississippi interior salt basins. The structural trend of the Arch is suspended along basement paleo-highs. The paleo-high beneath the Nebo-Hemphill field, as seen on reflection seismic data, is the nose of an Ouachitan thrust fault that was partially rifted during the opening of the Gulf of Mexico. The western limb of the Arch formed owing to differential subsidence expanding the stratigraphic section toward the southwest. The eastern limb of the Arch formed because of regional tilting to the east after deposition of the Claibornian Sparta Formation. Uplift of the LaSalle Arch occurred during the Late Cretaceous Period and is seen as a truncational unconformity within the Tayloran Demopolis Formation. The Wilcox and Midway groups of central Louisiana have been subdivided into three genetic sequences. They are T{sub 1} (the Midway.), T{sub 2} (the Holly Springs), and T{sub 3} (the Carrizo). A genetic sequence is bounded above and below by condensed sections and represents a progradation into the basin followed by transgression. Each sequence represents a potential major migration route for the crude oil. The high stand systems tract of T{sub 1} and T{sub 3} were deposited during falling sea level resulting in similar homogenous sheetlike sand bodies. The paleo-highs subtly controlled the location of depositional environments, but did not prevent progradation to the southwest. The highstand systems tract of T{sub 2} was deposited during rising sea level resulting in heterogenous sediment dominated deltaic deposits that are very different from T{sub 1} and T{sub 3}. Although the stratigraphic section expands to the southwest, giving the impression that the interval thins over the Arch, the LaSalle Arch did not control the location of depositional environments within T{sub 2}.

  12. Hybrid intervention for type A aortic arch interruption and a giant subclavian artery aneurysm in an adult.

    PubMed

    Oz, Kursad; Erek, Ersin; Yildirim, Aydin

    2016-06-01

    Interrupted aortic arch is a very rare but well-described congenital anomaly. Concomitant presentation of interrupted aortic arch and giant subclavian artery aneurysm is an unusual event in adulthood. To the best of our knowledge, hybrid intervention for type A aortic arch interruption with a giant aneurysm of the subclavian artery is an alternative approach for the management of these concomitant pathologies in adults. PMID:27071339

  13. Influences on Early and Medium-Term Survival Following Surgical Repair of the Aortic Arch

    PubMed Central

    Bashir, Mohamad; Field, Mark; Shaw, Matthew; Fok, Matthew; Harrington, Deborah; Kuduvalli, Manoj; Oo, Aung

    2014-01-01

    Objectives: It is now well established by many groups that surgery on the aortic arch may be achieved with consistently low morbidity and mortality along with relatively good survival compared to estimated natural history for a number of aortic arch pathologies. The objectives of this study were to: 1) report, compare, and analyze our morbidity and mortality outcomes for hemiarch and total aortic arch surgery; 2) examine the survival benefit of hemiarch and total aortic arch surgery compared to age- and sex-matched controls; and 3) define factors which influence survival in these two groups and, in particular, identify those that are modifiable and potentially actionable. Methods: Outcomes from patients undergoing surgical resection of both hemiarch and total aortic arch at the Liverpool Heart and Chest Hospital between June 1999 and December 2012 were examined in a retrospective analysis of data collected for The Society for Cardiothoracic Surgeons (UK). Results: Over the period studied, a total of 1240 patients underwent aortic surgery, from which 287 were identified as having undergone hemi to total aortic arch surgery under deep or moderate hypothermic circulatory arrest. Twenty three percent of patients' surgeries were nonelective. The median age at the time of patients undergoing elective hemiarch was 64.3 years and total arch was 65.3 years (P = 0.25), with 40.1% being female in the entire group. A total of 140 patients underwent elective hemiarch replacement, while 81 underwent elective total arch replacement. Etiology of the aortic pathology was degenerative in 51.2% of the two groups, with 87.1% requiring aortic valve repair in the elective hemiarch group and 64.2% in the elective total arch group (P < 0.001). Elective in-hospital mortality was 2.1% in the hemiarch group and 6.2% (P = 0.15) in the total arch group with corresponding rates of stroke (2.9% versus 4.9%, P = 0.47), renal failure (4.3% versus 6.2%, P = 0.54), reexploration for bleeding (4

  14. Tuning universality far from equilibrium

    PubMed Central

    Karl, Markus; Nowak, Boris; Gasenzer, Thomas

    2013-01-01

    Possible universal dynamics of a many-body system far from thermal equilibrium are explored. A focus is set on meta-stable non-thermal states exhibiting critical properties such as self-similarity and independence of the details of how the respective state has been reached. It is proposed that universal dynamics far from equilibrium can be tuned to exhibit a dynamical transition where these critical properties change qualitatively. This is demonstrated for the case of a superfluid two-component Bose gas exhibiting different types of long-lived but non-thermal critical order. Scaling exponents controlled by the ratio of experimentally tuneable coupling parameters offer themselves as natural smoking guns. The results shed light on the wealth of universal phenomena expected to exist in the far-from-equilibrium realm. PMID:23928853

  15. Paleostructural control of Dakota hydrocarbon accumulations on southern Moxa Arch, southwest Wyoming and northeast Utah

    SciTech Connect

    Blanke, S.J.; Reisser, K.D. )

    1990-05-01

    Production from the Lower Cretaceous Dakota Formation along the southern Moxa arch shows a number of anomalies in distribution and hydrocarbon character that can best be explained by complex interplay of the arch's depositional, structural, diagenetic, and thermal histories. The development of the Western Overthrust belt and its foreland basin largely controlled the orientation of the Dakota fluvial and deltaic systems. Differences in sandstone trends between the upper and lower Dakota resulted in different migration pathways and loci of oil and gas accumulations. Isochore mapping indicates that the onset of major structural growth of the Moxa arch began contemporaneous with deformation in the Overthrust belt during the Cretaceous Campanian. After early migration of hydrocarbons into the resulting structural/stratigraphic traps, subsequent diagenesis of Dakota sandstones, particularly in the downdip water legs of the reservoirs, effectively sealed the accumulations in their initial paleostructural position. Paleocene and Eocene structural compression reversed the original northward plunge of the arch and rotated it slightly to the east into its present structural configuration. Hydrodynamically driven convective heat flow has resulted in varying geothermal regimes within the area, increasing heat flow along most of the arch's crest, while cooling its southern portion. This phenomenon has affected gas-oil ratios and API gravities by enhancing or retarding thermal maturation of the trapped hydrocarbons.

  16. Role of the tranverse arch in stiffness of the human foot

    NASA Astrophysics Data System (ADS)

    Dias, Marcelo A.; Singh, Dhiraj K.; Bandi, Mahesh M.; Venkadesan, Madhusudhan; Mandre, Shreyas

    2015-03-01

    Human ancestors evolved from walking, around 6 million years (Ma) ago, to regular endurance running, around 2 Ma ago. Simultaneously, the feet evolved from a relatively flat structure like that of current day Chimpanzees (or our hands), to the modern human foot with two arches, a longitudinal and a transversal arch. The feet play a crucial role in locomotion by providing sufficient stiffness for propulsion, and being soft and pliable to absorb impacts and store energy elastically. Here we show that the transverse arch could play a central role in stiffness modulation. We first treat the foot as an elastic shell that is with intrinsic curvature. Calculations, numerics and physical experiments all show that for a foot-like shell, the stiffness has a power-law dependence on transverse curvature beyond a critical value. On the other hand, for purely longitudinally curved feet, or transverse curvature below the critical value, lead to low stiffness like a flat plate. Discrete realizations of a continuum shell, more closely resembling the human foot, also exhibit curvature induced stiffening. These results shed light on the role of the quintessentially human feature of a doubly arched foot, and suggest mechanical consequences of disorders such as a collapsed arch. HFSP RGY0091/2013.

  17. [The practical aspects of using "superelastic" arch wires in the edgewise technic].

    PubMed

    Linge, L; Dahm, S

    1994-12-01

    Ever increasing refinements in orthodontic treatment and the corresponding increase in technical demands are challenges to both the dentist in his/her practice and to the manufacturers of orthodontic materials. One interesting development has been the introduction of "super-elastic" arch wires, which have now been on the market for some years. Such arch wires are characterized by an excellent "shape memory", various levels of super-elasticity, a remarkable hysteresis, and temperature sensitivity. On the basis of findings from temperature controlled tests of arch wires in a "Lloyd 1000 R" testing machine, the following conclusions can be drawn. Shape memory can, from a clinical point of view, be regarded as being a positive feature. "Super-elasticity" is of lesser value, because conventional activation of edgewise arches rarely reaches the level of deformation necessary for super-elasticity to be called into play. Hysteresis and temperature sensitivity make a biomechanical control of the arch wires difficult. Reducing active forces by chilling the archwire brings relief to sore teeth. Whether this possibly leads to an improvement in blood circulation in the periodontal tissue, which would be biologically advantageous, should be made the subject of further research. PMID:7851829

  18. Study on Optimal Grouting Timing for Controlling Uplift Deformation of a Super High Arch Dam

    NASA Astrophysics Data System (ADS)

    Lin, Peng; Zhu, Xiaoxu; Li, Qingbin; Liu, Hongyuan; Yu, Yongjun

    2016-01-01

    A grouting model is developed for use during the grouting of the complex foundation of a super high arch dam. The purpose as to determine the optimal grouting timing and appropriate grouting pressure involved in controlling the uplift deformation of the dam. The model determines the optimal grouting time as the height of the arch dam increases with the concrete pouring, by checking the tensile stresses in the dam against standard specifications. The appropriate grouting pressures are given on the basis of the actual grouting pressures monitored during the upstream riverbed foundation grouting. An engineering procedure, applying the model, was then proposed and used during foundation grouting under the toe block of the Xiluodu super high-arch dam in south-western China. The quality of the foundation grouting was evaluated against the results from pressurized water permeability tests, acoustic wave velocity tests, elastic modulus tests and panoramic photographing of the rockmass on completion of the foundation grouting. The results indicated that the proposed grouting model can be applied to effectively reduce the uplift deformation and associated cracking risk for super high arch dams, and it can be concluded that the proposed engineering grouting procedure is a valuable tool for improving foundation grouting under the toe blocks of a super high arch dam.

  19. Analysis of arch-like bones: The rodent mandible as a case study.

    PubMed

    Vassallo, Aldo Iván

    2016-07-01

    Bone strength is determined by the mechanical properties of bone material, and the size and shape of the whole bone, i.e., its architecture. The mandible of vertebrates has been traditionally regarded as a beam oriented in relation to main masticatory loads, i.e., the longer dimension of its cross-section being parallel to the load. Rodents follow this pattern but, in addition, their mandible possesses an intriguing arch-like shape that is apparent when seen in the lateral view. Little attention was given to the structural capacity of this trait. The advantage of an arch is that it can withstand a greater load than a horizontal beam. The objective of this study was to model the rodent mandible like an arch to evaluate its structural strength. The bending moment in an arch-like mandible was 15-25% lower with respect to a beam-like mandible. Further, bending varies with mandible "slenderness" and incisor procumbency, a functionally relevant rodent trait. In the rodent Ctenomys talarum (Caviomorpha; Ctenomyidae), bone stress was substantially reduced when the mandible was modeled as an arch-like structure as compared with a beam-like structure, and safety factors were 15-34% higher. The shape of rodents' mandible might confer a functional advantage to high and repeatedly applied loads resulting from a unique feeding mode: gnawing. J. Morphol. 277:879-887, 2016. © 2016 Wiley Periodicals, Inc. PMID:27059294

  20. Arch coordination does not affect the stability in class III orthognathic surgery patients.

    PubMed

    Hong, Sung Ok; Ryu, Dong-Mok; Lee, Deok-Won; Jung, Jae Hoon

    2013-11-01

    The purpose of this study was to evaluate if the arch coordination manifested by preorthodontics had an effect on the short-term stability after orthognathic surgery by evaluating the B point, menton, overjet, and overbite. The subjects were 10 healthy adult female and male Koreans (mean age, 24.9 years) with insufficient arch coordination and 10 healthy adult female and male Koreans (mean age, 22 years) with sufficient arch coordination. All subjects had sagittal split ramus osteotomy with 1-piece maxillary Le Fort I surgery with/without genioplasty done from the same practitioner at Kyung Hee University Hospital at Gangdong from 2009 to 2011. All arch widths of the maxilla and mandible were measured. Cephalometric tracings of the subjects were made of the presurgical and postsurgical period with a follow-up at 3 months. Relapse was measured according to cephalometric tracing changes using the V-ceph Cephalometric Analysis Software version 5.5(Osstem, Seoul, South Korea). Insufficient arch coordination did not definitively affect the overall treatment outcome. There was significant difference in the horizontal dimensions of the mandible (vertical plane to point B, overjet) in the study group. The study group showed instability in orthodontic factors, whereas skeletal factors were stable. Vertical dimensions (horizontal plane to point B, horizontal plane to menton, overbite) were not statistically significant. PMID:24220471

  1. General equilibrium of an ecosystem.

    PubMed

    Tschirhart, J

    2000-03-01

    Ecosystems and economies are inextricably linked: ecosystem models and economic models are not linked. Consequently, using either type of model to design policies for preserving ecosystems or improving economic performance omits important information. Improved policies would follow from a model that links the systems and accounts for the mutual feedbacks by recognizing how key ecosystem variables influence key economic variables, and vice versa. Because general equilibrium economic models already are widely used for policy making, the approach used here is to develop a general equilibrium ecosystem model which captures salient biological functions and which can be integrated with extant economic models. In the ecosystem model, each organism is assumed to be a net energy maximizer that must exert energy to capture biomass from other organisms. The exerted energies are the "prices" that are paid to biomass, and each organism takes the prices as signals over which it has no control. The maximization problem yields the organism's demand for and supply of biomass to other organisms as functions of the prices. The demands and supplies for each biomass are aggregated over all organisms in each species which establishes biomass markets wherein biomass prices are determined. A short-run equilibrium is established when all organisms are maximizing and demand equals supply in every biomass market. If a species exhibits positive (negative) net energy in equilibrium, its population increases (decreases) and a new equilibrium follows. The demand and supply forces in the biomass markets drive each species toward zero stored energy and a long-run equilibrium. Population adjustments are not based on typical Lotka-Volterra differential equations in which one entire population adjusts to another entire population thereby masking organism behavior; instead, individual organism behavior is central to population adjustments. Numerical simulations use a marine food web in Alaska to

  2. Adiabatic evolution of plasma equilibrium

    PubMed Central

    Grad, H.; Hu, P. N.; Stevens, D. C.

    1975-01-01

    A new theory of plasma equilibrium is introduced in which adiabatic constraints are specified. This leads to a mathematically nonstandard structure, as compared to the usual equilibrium theory, in which prescription of pressure and current profiles leads to an elliptic partial differential equation. Topologically complex configurations require further generalization of the concept of adiabaticity to allow irreversible mixing of plasma and magnetic flux among islands. Matching conditions across a boundary layer at the separatrix are obtained from appropriate conservation laws. Applications are made to configurations with planned islands (as in Doublet) and accidental islands (as in Tokamaks). Two-dimensional, axially symmetric, helically symmetric, and closed line equilibria are included. PMID:16578729

  3. Phase coexistence far from equilibrium

    NASA Astrophysics Data System (ADS)

    Dickman, Ronald

    2016-04-01

    Investigation of simple far-from-equilibrium systems exhibiting phase separation leads to the conclusion that phase coexistence is not well defined in this context. This is because the properties of the coexisting nonequilibrium systems depend on how they are placed in contact, as verified in the driven lattice gas with attractive interactions, and in the two-temperature lattice gas, under (a) weak global exchange between uniform systems, and (b) phase-separated (nonuniform) systems. Thus, far from equilibrium, the notions of universality of phase coexistence (i.e., independence of how systems exchange particles and/or energy), and of phases with intrinsic properties (independent of their environment) are lost.

  4. Chemical Principles Revisited: Using the Equilibrium Concept.

    ERIC Educational Resources Information Center

    Mickey, Charles D., Ed.

    1981-01-01

    Discusses the concept of equilibrium in chemical systems, particularly in relation to predicting the position of equilibrium, predicting spontaneity of a reaction, quantitative applications of the equilibrium constant, heterogeneous equilibrium, determination of the solubility product constant, common-ion effect, and dissolution of precipitates.…

  5. The macroanatomical investigations on the aortic arch in porcupines (Hystrix cristata).

    PubMed

    Atalar, O; Yilmaz, S; Burma, O; Ilkay, E

    2003-12-01

    The anatomy of aortic arch in porcupine was studied. Angiography was applied to each of the three adult porcupines (two males, one female) following the injection of latex from the abdominal aorta for the examination of aortic arch. The results indicated that three arteries arose from aortic arch in porcupine. These were truncus brachiocephalicus, arteria carotis communis sinistra and arteria subclavia sinistra. The truncus brachiocephalicus in porcupine yielded arteria subclavia dextra and arteria carotis communis dextra. Truncus bicaroticus was absent. The origin of truncus costocervicalis (right) and arteria vertebralis (right) arose from a common root. Left or right axillary arteries seemed to be a continuation of subclavian arteries. The results of this study may contribute to the data in this area of science. PMID:14651485

  6. Subgross and macroscopic investigation of blood vessels originating from aortic arch in the chinchilla (Chinchilla lanigera).

    PubMed

    Ozdemir, V; Cevik-Demirkan, A; Türkmenoğlu, I

    2008-04-01

    A total of 10 adult, healthy, male chinchilla (Chinchilla lanigera) were used to investigate the vessels originating from aortic arch. Coloured latex was injected into the carotid arteries following conventional anatomical applications in all the chinchillas examined. The brachiocephalic trunk and the left subclavian artery arose from the aortic arch at the level of the second intercostal region in the thoracic cavity. The right and left subclavian arteries detached branches at the level of first intercostal region and divided into the following vessels: internal thoracic artery, dorsal scapular artery, vertebral artery, superficial cervical artery and axillar artery. The vessels originating from the aortic arch displayed some significant differences in chinchillas compared to rats, guinea pigs, rabbits, porcupines and other laboratory rodents. PMID:18005370

  7. Performance of 75 millimeter-bore arched outer-race ball bearings

    NASA Technical Reports Server (NTRS)

    Coe, H. H.; Hamrock, B. J.

    1976-01-01

    An investigation was performed to determine the operating characteristics of 75-mm bore, arched outer-race bearings, and to compare the data with those for a similar, but conventional, deep groove ball bearing. Further, results of an analytical study, made using a computer program developed previously, were compared with the experimental data. Bearings were tested up to 28,000 rpm shaft speed with a load of 2200 N (500 lb). The amount of arching was 0.13, 0.25, and 0.51 mm (.005, .010, and .020 in.). All bearings operated satisfactorily. The outer-race temperatures and the torques, however, were consistently higher for the arched bearings than for the conventional bearing.

  8. Dynamic response of arch bridges traversed by high-speed trains

    NASA Astrophysics Data System (ADS)

    Lacarbonara, Walter; Colone, Valerio

    2007-07-01

    A mechanical model describing the planar elasto-dynamics of arch bridges with general arch profiles is presented. The model is amenable to analytical or semi-analytical treatments and is effective for parametric studies, design of control systems or structural optimizations. The Ritz's energy approach is employed to calculate the solutions of the vibration eigenvalue problem—natural frequencies and mode shapes—and the forced responses to external excitations, namely those induced by the passage of trains. A closed-form solution of the bridge dynamic response to the transit of trains with arbitrary load distributions and running speeds is found and the train-induced resonances are accordingly discussed. In particular, three European high-speed trains—the French TGV, the Italian ETR 500, and the German ICE—traversing a lower-deck steel arch bridge are considered and the ensuing responses are investigated.

  9. Limit analysis assessment of experimental behavior of arches reinforced with GFRP materials

    NASA Astrophysics Data System (ADS)

    Basilio, Ismael; Fedele, Roberto; Lourenço, Paulo B.; Milani, Gabriele

    2014-10-01

    In this paper, a comparison between results furnished by a 3D FE upper bound limit analysis and experimental results for some reinforced masonry arches tested at the University of Minho (Portugal) is provided. While the delamination from arches support can be modelled only in an approximate way within limit analysis, the aim of the paper is to accurately reproduce the change in the failure mechanism observed in experimentation, due to the introduction of strengthening elements. Both experimental and numerical results showa clear change in the failure mechanism and in the corresponding ultimate peak load. A set of simulations is also performed on reinforced arches previously damaged, to investigate the role played by the reinforcement within a proper repairing procedure. Good correlation with experimental work and numerical simulations is achieved.

  10. Open aortic arch repair: state-of-the-art and future perspectives.

    PubMed

    Ouzounian, Maral; LeMaire, Scott A; Coselli, Joseph S

    2013-01-01

    Surgical procedures for the treatment of complex aortic arch pathology remain among the most challenging cardiovascular operations, incurring considerable risk for death and stroke. The purpose of this article is to describe the evolution of our approach to open repair of the aortic arch. Our arterial cannulation strategy has shifted from femoral and direct aortic to right axillary and more recently innominate artery cannulation. This transition has facilitated the administration of continuous antegrade cerebral perfusion and more moderate levels of hypothermia during complex repairs. Modifications in surgical technique, including arch reconstruction with the trifurcated graft, and the classical and frozen elephant trunk techniques have simplified the conduct of the operation. Experimental and clinical research supporting the evolution of our approach is discussed in this paper. PMID:24216527

  11. Performance of 75-millimeter bore arched outer-race ball bearings

    NASA Technical Reports Server (NTRS)

    Coe, H. H.; Hamrock, B. J.

    1976-01-01

    An investigation was performed to determine the operating characteristics of 75-mm bore, arched outer-race bearings, and to compare the data with those for a similar, but conventional, deep groove ball bearing. Further, results of an analytical study, made using a computer program developed previously, were compared with the experimental data. Bearings were tested up to 28,000 rpm shaft speed with a load of 2,200 N (500 lb). The amount of arching was 0.13, 0.25, and 0.51 mm (0.005, 0.010, and 0.020 in). All bearings operated satisfactorily. The outer-race temperatures and the torques, however, were consistently higher for the arched bearings than for the conventional bearings

  12. DYNAMIC EQUILIBRIUM IN THERAPEUTIC SITUATIONS.

    ERIC Educational Resources Information Center

    CARROLL, EDWARD J.

    THE CONCEPT OF DYNAMIC EQUILIBRIUM IS USED TO EXAMINE THE OCCURRENCE OF CHANGE IN A THERAPEUTIC INTERVIEW AND TO PROPOSE A THEORY OF THERAPY. BY ANALYZING THE WORKINGS OF THE PSYCHOSOCIAL SYSTEM THROUGH THE GENERAL SYSTEMS THEORY, IT IS POSSIBLE TO SEE HOW CHANGE OCCURS IN AN INDIVIDUAL FAMILY OR COMMUNITY. APPLIED TO A FAMILY INTERVIEW, THE MODEL…

  13. Magnetospheric equilibrium with anisotropic pressure

    SciTech Connect

    Cheng, C.Z.

    1991-07-01

    Self-consistent magnetospheric equilibrium with anisotropic pressure is obtained by employing an iterative metric method for solving the inverse equilibrium equation in an optimal flux coordinate system. A method of determining plasma parallel and perpendicular pressures from either analytic particle distribution or particle distribution measured along the satellite's path is presented. The numerical results of axisymmetric magnetospheric equilibrium including the effects of finite beta, pressure anisotropy, and boundary conditions are presented for a bi-Maxwellian particle distribution. For the isotropic pressure cases, the finite beta effect produces an outward expansion of the constant magnetic flux surfaces in relation to the dipole field lines, and along the magnetic field the toroidal ring current is maximum at the magnetic equator. The effect of pressure anisotropy is found to further expand the flux surfaces outward. Along the magnetic field lines the westward ring current can be peak away from the equator due to an eastward current contribution resulting from pressure anisotropy. As pressure anisotropy increases, the peak westward current can become more singular. The outer boundary flux surface has significant effect on the magnetospheric equilibrium. For the outer flux boundary resembling dayside compressed flux surface due to solar wind pressure, the deformation of the magnetic field can be quite different from that for the outer flux boundary resembling the tail-like surface. 23 refs., 17 figs.

  14. Understanding Thermal Equilibrium through Activities

    ERIC Educational Resources Information Center

    Pathare, Shirish; Huli, Saurabhee; Nachane, Madhura; Ladage, Savita; Pradhan, Hemachandra

    2015-01-01

    Thermal equilibrium is a basic concept in thermodynamics. In India, this concept is generally introduced at the first year of undergraduate education in physics and chemistry. In our earlier studies (Pathare and Pradhan 2011 "Proc. episteme-4 Int. Conf. to Review Research on Science Technology and Mathematics Education" pp 169-72) we…

  15. An investigation of equilibrium concepts

    NASA Technical Reports Server (NTRS)

    Prozan, R. J.

    1982-01-01

    A different approach to modeling of the thermochemistry of rocket engine combustion phenomena is presented. The methodology described is based on the hypothesis of a new variational principle applicable to compressible fluid mechanics. This hypothesis is extended to treat the thermochemical behavior of a reacting (equilibrium) gas in an open system.

  16. Externalized Guidewires to Facilitate Fenestrated Endograft Deployment in the Aortic Arch

    PubMed Central

    Joseph, George; Premkumar, Prabhu; Thomson, Viji; Varghese, Mithun; Selvaraj, Dheepak; Sahajanandan, Raj

    2016-01-01

    Purpose: To describe a precannulated fenestrated endograft system utilizing externalized guidewires to facilitate aortic arch endovascular repair and to report its use in 2 patients with challenging anatomy. Technique: For distal arch repair, a fenestration for the left subclavian artery (LSA) is made onsite in a standard thoracic endograft tailored to the patient anatomy; it is precannulated with a nitinol guidewire (NGw), which is passed from the femoral artery and externalized from the left brachial artery prior to endograft delivery system introduction over a parallel stiff guidewire. Steps are then taken to remove guidewire intertwining, prevent NGw wrapping around the delivery system, and orient the LSA fenestration superiorly when the delivery system moves into the arch. Gentle traction on the ends of the NGw during endograft deployment facilitates proper fenestration alignment. A covered stent is deployed in the LSA fenestration. The technique is illustrated in a patient with congenital coarctation of the aorta and descending aortic aneurysm. For total arch repair, endograft fenestrations are made for all 3 arch branches; the left common carotid artery (LCCA) and LSA fenestrations are each cannulated with NGws, which travel together from the femoral artery, pass through a LSA snare loop, and are exteriorized from the LCCA. After endograft deployment, the innominate artery fenestration is separately cannulated using right brachial access. Placement of a parallel externalized hydrophilic guidewire passing through the LCCA fenestration (but not the LSA snare loop) and removal of the LCCA fenestration NGw allows exteriorization of the LSA fenestration NGw from the left brachial artery by pulling the LSA snare. Covered stents are deployed in all 3 fenestrations. The technique is presented in a patient with type B aortic dissection. Conclusion: Use of the precannulated fenestrated endograft system described is feasible and has the potential to make aortic arch

  17. Dependence of aortic arch morphogenesis on intracardiac blood flow in the left atrial ligated chick embryo.

    PubMed

    Hu, Norman; Christensen, Douglas A; Agrawal, Amit K; Beaumont, Charity; Clark, Edward B; Hawkins, John A

    2009-05-01

    Partial left atrial ligation before cardiac septation redistributes intracardiac blood flow and produces left ventricular hypoplasia in the chick. We hypothesized that redistributed intracardiac blood flow adversely alters aortic arch development. We ligated the left atrial appendage with a 10-0 nylon suture at stage 21 chick embryos, then reincubated up to stage 34. Sham embryos had a suture tied adjacent to the atrial wall, and normal controls were unoperated. We measured simultaneous atrioventricular (AV) and dorsal aortic (DAo) blood velocities from stage 24 embryos with an ultrasound pulsed-Doppler flow meter; and the left and right third and fourth aortic arch blood flow with a laser-Doppler flow meter. Ventricular and atrial cross-sectional areas were measured from sequential video fields for planimetry. Intracardiac flow patterns were imaged on video by injecting India ink into the vitelline vein. In separate embryos, radiopaque microfil was injected into the cardiovascular system for micro-CT scanning. We analyzed the morphologic characteristics of the heart at stage 34. Active AV and DAo stroke volume (mm(3)), right third and fourth aortic arch blood flow (mm(3)/s) were all decreased in ligated embryos (P < 0.05) when compared with normal and sham embryos. Ventricular end-diastolic volume versus normal and sham embryos decreased by 45% and 46%, respectively (P < 0.05). India ink injection revealed altered right aortic arch flow patterns in the ligated embryos compared with normal embryos. micro-CT imaging confirmed altered arch morphogenesis. Alterations in intracardiac blood flow disrupt both early cardiac morphogenesis and aortic arch selection. PMID:19322826

  18. Tectonic history of Sweetgrass Arch, Montana and Alberta-key to finding new hydrocarbons

    SciTech Connect

    Shepard, W. Shepard, B.

    1985-05-01

    The Sweetgrass arch of northwestern Montana and southern Alberta is a major ancient structural feature. Initial anticlinal emplacement occurred during the early Paleozoic and was parallel with the cratonic margin. Strong uplift followed by peneplanation occurred during the Late Jurassic and basal Cretaceous during the westward drifting of the North American plate following the breakup of Pangea. During Cretaceous and early Tertiary times, the Sweetgrass arch was quiescent, but was rejuvenated in mid to late Tertiary, upwarped by a basement flexure to its present structural configuration: a 200 mi (322 km) long, north-plunging anticline showing 10,000 ft (350 m) of structural relief. Midway down its plunge, the anticline is offset 30 mi (48 km) by a right-lateral transcurrent fault. During Late Cretaceous and early Tertiary, plutonic uplifts were emplaced on the east flank, forming traps for oil then migrating updip from the Williston and Alberta basins. Oil and gas accumulated in Mississippian, Jurassic, and basal Cretaceous reservoirs in structural and stratigraphic traps around these plutonic uplifts. Subsequent late Tertiary doming of the Sweetgrass arch tilted the earlier structural traps and drained them, resulting in remigration of much of the oil and gas to the crest of the arch. The tilting failed to destroy many of the stratigraphic traps. As a result, down the flanks of the Sweetgrass arch are many frozen stratigraphic traps including Cut Bank field, the largest single-pay stratigraphic trap in the north Rockies. On the crest are large structure accumulations of remigrated oil at Kevin Sunburst and Pondera. Evidence of remigration is recorded by live oil show tracks in the reservoirs and remnant gas caps throughout the area of earlier accumulations. A potential exists for finding new frozen traps on the flanks and remigrated oil accumulations on or near the crest of the Sweetgrass arch.

  19. High Palatoglossal Arch: A New Indication for Pre-prosthetic Surgery.

    PubMed

    Raikwar, Kanchan R; Ghodke, Monali; Garde, Janardan B; Suryavanshi, Rajendrakumar

    2016-07-01

    Pre-prosthetic surgery helps to overcome the challenge of prosthetic rehabilitation of the patient including restoration of the best masticatory function possible, combined with restoration or improvement of dental and facial esthetics. Maxillary denture prosthesis fabrication should include thorough examination of the soft palate and palatoglossal arch anatomy. This case report emphasizes on high palatoglossal arch as a rare and new cause of loss of posterior palatal seal and thereby retention of maxillary denture with rational, treated by pre-prosthetic surgery, ever reported in literature. PMID:27408462

  20. Isogeometric analysis: a powerful numerical tool for the elastic analysis of historical masonry arches

    NASA Astrophysics Data System (ADS)

    Cazzani, Antonio; Malagù, Marcello; Turco, Emilio

    2016-03-01

    We illustrate a numerical tool for analyzing plane arches such as those frequently used in historical masonry heritage. It is based on a refined elastic mechanical model derived from the isogeometric approach. In particular, geometry and displacements are modeled by means of non-uniform rational B-splines. After a brief introduction, outlining the basic assumptions of this approach and the corresponding modeling choices, several numerical applications to arches, which are typical of masonry structures, show the performance of this novel technique. These are discussed in detail to emphasize the advantage and potential developments of isogeometric analysis in the field of structural analysis of historical masonry buildings with complex geometries.

  1. Properties of some statistics for AR-ARCH model with application to technical analysis

    NASA Astrophysics Data System (ADS)

    Huang, Xudong; Liu, Wei

    2009-03-01

    In this paper, we investigate some popular technical analysis indexes for AR-ARCH model as real stock market. Under the given conditions, we show that the corresponding statistics are asymptotically stationary and the law of large numbers hold for frequencies of the stock prices falling out normal scope of these technical analysis indexes under AR-ARCH, and give the rate of convergence in the case of nonstationary initial values, which give a mathematical rationale for these methods of technical analysis in supervising the security trends.

  2. Neonate with VACTERL Association and a Branchial Arch Anomaly without Hydrocephalus

    PubMed Central

    Velazquez, Danitza; Pereira, Elaine; Havranek, Thomas

    2015-01-01

    VACTERL (vertebral anomalies, anal atresia, cardiac defect, tracheoesophageal fistula, renal anomaly, limb anomalies) is an association of anomalies with a wide spectrum of phenotypic expression. While the majority of cases are sporadic, there is evidence of an inherited component in a small number of patients as well as the potential influence of nongenetic risk factors (maternal diabetes mellitus). Presence of hydrocephalus has been reported in VACTERL patients (VACTERL-H) in the past, with some displaying branchial arch anomalies. We report the unique case of an infant of diabetic mother with VACTERL association and a branchial arch anomaly—in the absence of hydrocephalus. PMID:26929876

  3. Vascular airway compression management in a case of aortic arch and descending thoracic aortic aneurysm

    PubMed Central

    Kumar, Alok; Dutta, Vikas; Negi, Sunder; Puri, G. D.

    2016-01-01

    Airway compression due to distal aortic arch and descending aortic aneurysm repair has been documented. This case of tracheal and left main stem bronchus compression due to aortic aneurysm occurred in a 42-year-old man. The airway compression poses a challenge for the anesthesiologist in airway management during aortic aneurysm repair surgery. The fiber-optic bronchoscope is very helpful in decision-making both preoperatively and postoperatively in such cases. We report a case of airway compression in a 42-year-old patient who underwent elective distal aortic arch and descending aortic aneurysm repair. PMID:27397474

  4. Vascular airway compression management in a case of aortic arch and descending thoracic aortic aneurysm.

    PubMed

    Kumar, Alok; Dutta, Vikas; Negi, Sunder; Puri, G D

    2016-01-01

    Airway compression due to distal aortic arch and descending aortic aneurysm repair has been documented. This case of tracheal and left main stem bronchus compression due to aortic aneurysm occurred in a 42-year-old man. The airway compression poses a challenge for the anesthesiologist in airway management during aortic aneurysm repair surgery. The fiber-optic bronchoscope is very helpful in decision-making both preoperatively and postoperatively in such cases. We report a case of airway compression in a 42-year-old patient who underwent elective distal aortic arch and descending aortic aneurysm repair. PMID:27397474

  5. Mathematical modeling and numerical analysis of thermal distribution in arch dams considering solar radiation effect.

    PubMed

    Mirzabozorg, H; Hariri-Ardebili, M A; Shirkhan, M; Seyed-Kolbadi, S M

    2014-01-01

    The effect of solar radiation on thermal distribution in thin high arch dams is investigated. The differential equation governing thermal behavior of mass concrete in three-dimensional space is solved applying appropriate boundary conditions. Solar radiation is implemented considering the dam face direction relative to the sun, the slop relative to horizon, the region cloud cover, and the surrounding topography. It has been observed that solar radiation changes the surface temperature drastically and leads to nonuniform temperature distribution. Solar radiation effects should be considered in thermal transient analysis of thin arch dams. PMID:24695817

  6. Simple and highly efficient chiral dopant molecules possessing both rod- and arch-like units.

    PubMed

    Kishikawa, Keiki; Aoyagi, Shota; Kohri, Michinari; Taniguchi, Tatsuo; Takahashi, Masahiro; Kohmoto, Shigeo

    2014-09-14

    A simple chiral dopant molecule (R)-1 with both rod- and arch-like units was prepared, and extremely large helical twisting powers (+123 to +228 μm(-1)) in nematic liquid crystal phases were achieved. We have demonstrated that the introduction of an arch-like unit in addition to rod-like units is highly effective in controlling the helical molecular alignment. As an application of the dopant, induction of blue phases by addition of a small amount of it was achieved. PMID:25041949

  7. Equine pericardial roll graft replacement of infected pseudoaneurysm of the aortic arch

    PubMed Central

    2012-01-01

    Resection of the infected aorta, debridement of the surrounding tissue, in situ graft replacement, and omentopexy is the standard procedure for treating infected aortic aneurysms, but the question of which graft material is optimal is still a matter of controversy. We recently treated a patient with an infected thoracic aortic aneurysm. The aneurysm was located in the proximal aortic arch. Because the patients had previously undergone abdominal surgery, the aortic arch were replaced in situ with a branched equine pericardial roll grafts. The patient is alive and well 23 months after the operation. PMID:22583570

  8. Endovascular Treatment for Proximal Anastomotic Pseudoaneurysm after Total Arch Replacement in Behcet's Disease.

    PubMed

    Sakata, Tomoki; Ueda, Hideki; Watanabe, Michiko; Kohno, Hiroki; Tamura, Yusaku; Abe, Shinichiro; Inage, Yuichi; Ikeuchi, Hiroki; Kanda, Tomoyoshi; Fujii, Masahiko; Matsumiya, Goro

    2016-07-01

    A 17-year-old patient underwent total arch replacement for aortic arch aneurysm due to vascular Behcet's disease (BD). Follow-up computed tomography, performed 6 months after the operation, demonstrated pseudoaneurysm formation at the proximal anastomotic site. We performed endovascular treatment and used a short stent graft that was originally designed for abdominal aortic aneurysm. To avoid the occlusion of the coronary or brachiocephalic artery (BCA) due to stent graft migration, we used right ventricular rapid pacing and BCA ballooning. Thus, we believe that endovascular treatment can be used for anastomotic complications in the ascending aorta after open surgery for connective tissue disorders including BD. PMID:27174345

  9. Aortic Arch Mycotic Aneurysm Due to Scedosporium Apiospermum Reconstructed With Homografts.

    PubMed

    Blasco-Lucas, Arnau; Reyes-Juárez, José Luis; Nazarena Pizzi, María; Permanyer, Eduard; Evangelista, Arturo; Galiñanes, Manuel

    2015-06-01

    A 39-year-old female, active parenteral drug user was diagnosed of spondylodiscitis. A computed tomography (CT) scan showed an extensive aortic arch aneurysm. A positron emission tomography (PET)-CT scan, showing significant aortic wall uptake of the tracer through the whole aortic arch and the D8-D9 intervertebral disc, allowed us to suspect an aortitis despite negative blood cultures. The aneurysm was resected and reconstructed with 2 aortic homografts. Cultures of specimens from the aortic wall were positive to the fungi Scedosporium apiospermum. A new PET-CT scan 4 months after surgery showed absence of tracer uptake both at the homografts site and intervertebral disc. PMID:26046885

  10. Thymopharyngeal duct cyst: MR imaging of a third branchial arch anomaly in a neonate.

    PubMed

    Vade, A; Griffiths, A; Hotaling, A; Eisenbeis, J F; Husain, A N

    1994-01-01

    Third branchial arch anomalies are rare. The authors present a case report of a neonate with a rapidly growing neck mass due to cystic dilation of a persistent thymopharyngeal duct, which is a derivative of the third branchial arch. The presence of thyroid and thymic tissue in the cyst wall, the communication of the cyst with the piriform sinus, and the relationship of the cyst to carotid vessels and the sternomastoid muscle were consistent with the features of a thymopharyngeal duct cyst embedded in the thyroid gland. PMID:7949690

  11. On the connection between ARCH time series and non-extensive statistical mechanics

    NASA Astrophysics Data System (ADS)

    Duarte Queirós, Sílvio M.

    2004-12-01

    The ARCH(1) is a generator of stochastic discrete time series, { ɛt}, widely used in finance and characterised by conditional time-varying (and correlated) second-order moment. It involves a parameter, β and a noise, η. In this work one presents, through an analytical result, that ARCH(1) stationary distributions are well approached by the distributions that maximise the entropy, S q= {1-∫[p(x)] q dx }/{1-q}. Using the generalised Kullback-Leibler relative entropy, Iq, one also quantifies the degree of dependence between variables ɛt and ɛt‧ and shows that the degree of dependence increases with parameter β.

  12. LOFT/FET complex. Construction view of abutment footings for arches of ...

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

    LOFT/FET complex. Construction view of abutment footings for arches of hangar (TAN-629). Tunnels between basement of hangar and control building (TAN-630) had to fit between arches. (Note concrete work taking place at hole at lower edge of view. This photo may document unexpected bubble in underlying lava rock. It was dumped full of concrete and a footing made. Source: Interview with John DeClue). Date: December 19, 1957. Photographer: Jack L. Anderson. INEEL negative no. 57-6203 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  13. Mathematical Modeling and Numerical Analysis of Thermal Distribution in Arch Dams considering Solar Radiation Effect

    PubMed Central

    Mirzabozorg, H.; Hariri-Ardebili, M. A.; Shirkhan, M.; Seyed-Kolbadi, S. M.

    2014-01-01

    The effect of solar radiation on thermal distribution in thin high arch dams is investigated. The differential equation governing thermal behavior of mass concrete in three-dimensional space is solved applying appropriate boundary conditions. Solar radiation is implemented considering the dam face direction relative to the sun, the slop relative to horizon, the region cloud cover, and the surrounding topography. It has been observed that solar radiation changes the surface temperature drastically and leads to nonuniform temperature distribution. Solar radiation effects should be considered in thermal transient analysis of thin arch dams. PMID:24695817

  14. Lip and tongue pressures related to dental arch and oral cavity size in Australian aborigines.

    PubMed

    Proffit, W R; McGlone, R E; Barrett, M J

    1975-01-01

    Although the oral cavity and dental arches of the Australian aborigine are large, studies of lingual and labial pressures indicate that the tongue is neither unusually large nor strong. The Australian aborigine's pharyngeal cavity is smaller in height and depth than that of the American; just the opposite is true for the oral cavity. To the extent that environmental factors are important at all, the resting pressure of the lips, not tongue pressure during swallowing, is probably the significant determinant of dental arch dimensions. PMID:1059654

  15. Vibration analysis of shear deformable circular arches by the differential quadrature method

    NASA Astrophysics Data System (ADS)

    Kang, K.; Bert, C. W.; Striz, A. G.

    1995-06-01

    The differential quadrature method is applied in the computation of the eigenvalues of the equations of motion governing in-plane and out-of-plane vibration of circular arches, based on the Bresse-Timoshenko beam theory in which both rotatory inertia and shear deformation are taken into account. Fundamental frequencies are calculated for arches of rectangular and circular cross sections under clamped-clamped end conditions and the results are compared with numerical solutions by another method. The present method gives good accuracy with only a limited number of grid points.

  16. Neonate with VACTERL Association and a Branchial Arch Anomaly without Hydrocephalus.

    PubMed

    Velazquez, Danitza; Pereira, Elaine; Havranek, Thomas

    2016-03-01

    VACTERL (vertebral anomalies, anal atresia, cardiac defect, tracheoesophageal fistula, renal anomaly, limb anomalies) is an association of anomalies with a wide spectrum of phenotypic expression. While the majority of cases are sporadic, there is evidence of an inherited component in a small number of patients as well as the potential influence of nongenetic risk factors (maternal diabetes mellitus). Presence of hydrocephalus has been reported in VACTERL patients (VACTERL-H) in the past, with some displaying branchial arch anomalies. We report the unique case of an infant of diabetic mother with VACTERL association and a branchial arch anomaly-in the absence of hydrocephalus. PMID:26929876

  17. Defining the southwestern end of the Blytheville Arch, northeastern Arkansas: delimiting a seismic source zone in the New Madrid region

    USGS Publications Warehouse

    Crone, A.J.

    1998-01-01

    Vibroseis seismic-reflection profiles around the southwestern end of the Blytheville arch document the southwesternly extent of the arch and refine the length of a fault zone that coincides with the arch. The 74.3 km of newly interpreted profiles and previously described profiles form a network of lines across and around the southern end of the arch. The southwestern terminus of the arch is defined by the absence of significantly upwarped or extensively disrupted reflectors, which are diagnostic traits of the arch where it is well developed. The arch is 134 km long as documented here, which is only slightly longer than the length reported by previous studies. Differing opinions about the magnitude of the 1811-1812 New Madrid earthquakes could be partly explained by substantially longer seismic source zones, but this minor increase in source zone length does not reconcile the large differences in magnitude estimates of the events. If future earthquake ruptures associated with the arch are confined to areas of extensive deformation, then this well documented southwestern termination precludes a rupture substantially longer than ~134 km along the zone of seismicity that coincides with the axis of the Reelfoot rift.

  18. Dental arch dimensions in the mixed dentition: a study of Brazilian children from 9 to 12 years of age

    PubMed Central

    LOULY, Fabiane; NOUER, Paulo Roberto Aranha; JANSON, Guilherme; PINZAN, Arnaldo

    2011-01-01

    Objective This study evaluated dental arch dimensional changes of Brazilian children. Material and methods Dental casts were taken from 66 children (29 males; 37 females) with normal occlusion selected among 1,687 students from public and private schools aged 9, 10, 11 and 12 years, according to the following criteria: Class I canine and molar relationships; well-aligned upper and lower dental arches; mixed dentition; good facial symmetry; no previous orthodontic treatment. Dental arch dimensions were taken by one examiner using the Korkhaus’ compass and a digital pachymeter. ANOVA test was applied to compare the arch dimensions at the different ages and the t-test was used to compare the arch dimensions of male and female subjects. Arch forms were compared by means of chi-square tests. Results Only the maxillary anterior segment length showed a statistically significant increase from 10 to 12 years of age. Males had a significantly larger maxillary depth than females at the age range evaluated. The predominant dental arch form found was elliptical. Conclusion In the studied age range, anterior maxillary length increased from 10 to 12 years of age, males had larger maxillary depth than females and the predominant arch form was elliptical. PMID:21552719

  19. Maxillary Arch Dimensions and Spectral Characteristics of Children with Cleft Lip and Palate Who Produce Middorsum Palatal Stops

    ERIC Educational Resources Information Center

    Zajac, David J.; Cevidanes, Lucia; Shah, Sonam; Haley, Katarina L.

    2012-01-01

    Purpose: The purpose of this study was twofold: (a) to determine maxillary arch dimensions of children with repaired cleft lip and palate (CLP) who produced middorsum palatal stops and (b) to describe some spectral characteristics of middorsum palatal stops. Method: Maxillary arch width, length, and height dimensions and first spectral moments of…

  20. Non-Equilibrium Properties from Equilibrium Free Energy Calculations

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; Wilson, Michael A.

    2012-01-01

    Calculating free energy in computer simulations is of central importance in statistical mechanics of condensed media and its applications to chemistry and biology not only because it is the most comprehensive and informative quantity that characterizes the eqUilibrium state, but also because it often provides an efficient route to access dynamic and kinetic properties of a system. Most of applications of equilibrium free energy calculations to non-equilibrium processes rely on a description in which a molecule or an ion diffuses in the potential of mean force. In general case this description is a simplification, but it might be satisfactorily accurate in many instances of practical interest. This hypothesis has been tested in the example of the electrodiffusion equation . Conductance of model ion channels has been calculated directly through counting the number of ion crossing events observed during long molecular dynamics simulations and has been compared with the conductance obtained from solving the generalized Nernst-Plank equation. It has been shown that under relatively modest conditions the agreement between these two approaches is excellent, thus demonstrating the assumptions underlying the diffusion equation are fulfilled. Under these conditions the electrodiffusion equation provides an efficient approach to calculating the full voltage-current dependence routinely measured in electrophysiological experiments.

  1. A Novel Surgical Technique for Right-Sided Interrupted Aortic Arch by Interposition of a Pulmonary Autograft Tube.

    PubMed

    Kato, Nobuyasu; Yamagishi, Masaaki; Miyazaki, Takako; Maeda, Yoshinobu; Asada, Satoshi; Hongu, Hisayuki; Yamashita, Eijiro; Yaku, Hitoshi

    2016-08-01

    Right-sided interrupted aortic arch (IAA) is a rare cardiac anomaly. In general, the right bronchus sits higher than the left bronchus, so aortic arch reconstruction with a direct anastomosis has a risk of tracheal and bronchial obstruction. This report describes the successful definitive repair of a right-sided IAA in a 2.5-kg neonate by aortic arch reconstruction with a pulmonary autograft tube (PA tube). Postoperative three-dimensional multidetector computed tomography showed the reconstructed aortic arch without airway obstruction or aortic stenosis. The use of a PA tube is a simple and useful technique for aortic arch reconstruction in patients with a high risk of tracheal andbronchial obstruction, such as right-sided IAA. PMID:27449446

  2. Phonon Mapping in Flowing Equilibrium

    NASA Astrophysics Data System (ADS)

    Ruff, J. P. C.

    2015-03-01

    When a material conducts heat, a modification of the phonon population occurs. The equilibrium Bose-Einstein distribution is perturbed towards flowing-equilibrium, for which the distribution function is not analytically known. Here I argue that the altered phonon population can be efficiently mapped over broad regions of reciprocal space, via diffuse x-ray scattering or time-of-flight neutron scattering, while a thermal gradient is applied across a single crystal sample. When compared to traditional transport measurements, this technique offers a superior, information-rich new perspective on lattice thermal conductivity, wherein the band and momentum dependences of the phonon thermal current are directly resolved. The proposed method is benchmarked using x-ray thermal diffuse scattering measurements of single crystal diamond under transport conditions. CHESS is supported by the NSF & NIH/NIGMS via NSF Award DMR-1332208.

  3. Connective stability of competitive equilibrium

    NASA Technical Reports Server (NTRS)

    Siljak, D. D.

    1975-01-01

    The purpose of this paper is to derive necessary and sufficient conditions for the connective stability of nonlinear matrix systems described by the equation x-dot = A(t, x) x, where the matrix A(t, x) has time-varying nonlinear elements. The results obtained can be used to study the stability of competitive equilibrium in fields as diverse as economics and engineering, model ecosystems, and the arms race.-

  4. Punctuated equilibrium comes of age

    NASA Astrophysics Data System (ADS)

    Gould, Stephan Jay; Eldredge, Niles

    1993-11-01

    The intense controversies that surrounded the youth of punctuated equilibrium have helped it mature to a useful extension of evolutionary theory. As a complement to phyletic gradualism, its most important implications remain the recognition of stasis as a meaningful and predominant pattern within the history of species, and in the recasting of macroevolution as the differential success of certain species (and their descendants) within clades.

  5. Aneurysm of an Aberrant Right Subclavian Artery Successfully Excluded by a Thoracic Aortic Stent Graft with Supra-aortic Bypass of Three Arch Vessels

    SciTech Connect

    Munneke, Graham J. Loosemore, Thomas M.; Belli, Anna-Maria; Thompson, Matt M.; Morgan, Robert A.

    2005-06-15

    An aberrant right subclavian artery (ARSA) arising from a left-sided aortic arch is the fourth most common aortic arch anomaly. Aneurysmal dilatation of the ARSA requires treatment because of the associated risk of rupture. We present a case where supra-aortic bypass of the arch vessels was performed to facilitate exclusion of the aneurysm by a thoracic aortic stent graft.

  6. An Automatic Method for Geometric Segmentation of Masonry Arch Bridges for Structural Engineering Purposes

    NASA Astrophysics Data System (ADS)

    Riveiro, B.; DeJong, M.; Conde, B.

    2016-06-01

    Despite the tremendous advantages of the laser scanning technology for the geometric characterization of built constructions, there are important limitations preventing more widespread implementation in the structural engineering domain. Even though the technology provides extensive and accurate information to perform structural assessment and health monitoring, many people are resistant to the technology due to the processing times involved. Thus, new methods that can automatically process LiDAR data and subsequently provide an automatic and organized interpretation are required. This paper presents a new method for fully automated point cloud segmentation of masonry arch bridges. The method efficiently creates segmented, spatially related and organized point clouds, which each contain the relevant geometric data for a particular component (pier, arch, spandrel wall, etc.) of the structure. The segmentation procedure comprises a heuristic approach for the separation of different vertical walls, and later image processing tools adapted to voxel structures allows the efficient segmentation of the main structural elements of the bridge. The proposed methodology provides the essential processed data required for structural assessment of masonry arch bridges based on geometric anomalies. The method is validated using a representative sample of masonry arch bridges in Spain.

  7. Double aortic arch as a source of airway obstruction in a child

    PubMed Central

    Das, Sambhunath; Nair, Vinitha V.; Airan, Balram

    2015-01-01

    Double aortic arch (DAA) is a congenital vascular anomaly. The diagnosis was difficult till the child was symptomatic, and other causes were ruled out. We present the interesting images of a child of respiratory distress because of tracheal compression from DAA. PMID:25566726

  8. Application of the Bolton Relay Device for Thoracic Endografting In or Near the Aortic Arch

    PubMed Central

    Riambau, Vincent

    2015-01-01

    Endovascular correction of aortic arch pathology remains a challenge, with a variety of techniques proposed over the years to minimize complications and enhance the probability of a successful result. A variety of approaches have been developed in order to deal with the aortic arch pathology and its idiosyncrasies. We review potential interventional techniques for the repair of aortic arch pathologies, beginning with conventional aortic arch surgery, followed by hybrid treatments and those along the endovascular spectrum (parallel and fenestrated endografts, scalloped endografts, and ascending and new branched endografts). We finish with an overview of all the Bolton Medical (Barcelona, Spain and Sunrise, FL, USA) thoracic platforms. Endovascular techniques show acceptable results in selected cases. Both proximal Bolton Relay configurations (with and without a bare stent) offer conformability and accuracy on deployment with very low rates of stroke. Fenestrated and scalloped designs are also useful for selected cases. Ascending and branched Bolton devices are very promising platforms for a serious, full endovascular approach to the aorta. PMID:26798752

  9. Critical Pedagogy: Constructing an Arch of Social Dreaming and a Doorway to Hope.

    ERIC Educational Resources Information Center

    McLaren, Peter

    1991-01-01

    Constructing an arch of social dreaming means developing a politics of difference that actively contests the devaluation of persons relegated as "others." In this connection, features of critical pedagogy, the role it plays in the struggle against current neoconservatism, and the importance of language are considered. (SLD)

  10. Haemodynamics in the mouse aortic arch computed from MRI-derived velocities at the aortic root.

    PubMed

    Van Doormaal, Mark A; Kazakidi, Asimina; Wylezinska, Marzena; Hunt, Anthony; Tremoleda, Jordi L; Protti, Andrea; Bohraus, Yvette; Gsell, Willy; Weinberg, Peter D; Ethier, C Ross

    2012-11-01

    Mice are widely used to investigate atherogenesis, which is known to be influenced by stresses related to blood flow. However, numerical characterization of the haemodynamic environment in the commonly studied aortic arch has hitherto been based on idealizations of inflow into the aorta. Our purpose in this work was to numerically characterize the haemodynamic environment in the mouse aortic arch using measured inflow velocities, and to relate the resulting shear stress patterns to known locations of high- and low-lesion prevalence. Blood flow velocities were measured in the aortic root of C57/BL6 mice using phase-contrast MRI. Arterial geometries were obtained by micro-CT of corrosion casts. These data were used to compute blood flow and wall shear stress (WSS) patterns in the arch. WSS profiles computed using realistic and idealized aortic root velocities differed significantly. An unexpected finding was that average WSS in the high-lesion-probability region on the inner wall was actually higher than the WSS in the low-probability region on the outer wall. Future studies of mouse aortic arch haemodynamics should avoid the use of idealized inflow velocity profiles. Lesion formation does not seem to uniquely associate with low or oscillating WSS in this segment, suggesting that other factors may also play a role in lesion localization. PMID:22764131

  11. A quantitative approach for measuring crowding in the dental arch: Fourier descriptors.

    PubMed

    Lestrel, Pete E; Takahashi, Osamu; Kanazawa, Eisaku

    2004-06-01

    Dental crowding is defined as a discrepancy between tooth size and jaw size that results in a misalignment of the tooth row. Proposed reasons for crowding include excessively large teeth, small jaws, and a combination of both. Nevertheless, the parameters that would allow the prediction of crowding have not been identified. This study compared the shape of crowded and uncrowded dental arches, matched for size and sex. The application of elliptical Fourier functions (EFFs) provided an accurate numeric description of the dental arch form. Dental casts from the Nihon University School of Dentistry at Matsudo, Chiba, Japan, were studied. Group I, the control group, consisted of 118 dental cast pairs (49 female, 69 male, aged 20.40 +/- 1.68 years [mean +/- SD]) with little or no crowding. Group II, which exhibited crowding, consisted of 78 dental cast pairs (64 female, 14 male, aged 19.67 +/- 4.95 years). From photographs, a set of 24 homologous points describing the tooth row was identified. These points were then fitted with EFFs. Each maxillary and mandibular outline was subsequently standardized for size by scaling the bounded area to a constant 10,000 mm(2). These "shape only" data were used to assess differences between arches in the 2 groups. By multivariate analysis of variance, statistically significant shape differences between groups I and II were obtained for both arches. Patients with crowding exhibited more variability than did the controls. This variability was illustrated with canonical axes derived from discriminant function analysis. PMID:15179396

  12. [Antegrade unilateral perfusion of the brain through the brachiocephalic trunk in operations on the aortic arch].

    PubMed

    Kozlov, B N; Panfilov, D S; Kuznetsov, M S; Ponomarenko, I V; Nasrashvili, G G; Shipulin, V M

    2016-01-01

    Presented herein is a technique of unilateral antegrade perfusion of the brain in operations on the aortic arch. The method makes it possible to perform both systemic artificial circulation and adequate physiological perfusion of the brain, promoting minimization of the number of neurological complications. PMID:27100557

  13. 21. U.S. Route 60 elliptical spandrel arch grade separation structure, ...

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

    21. U.S. Route 60 elliptical spandrel arch grade separation structure, built in 1959. This view shows the east elevation. This structure type was used nearly exclusively at the parkway's primary access points where consideration of vertical and horizontal clearances as well as aesthetic concerns influenced design selection. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  14. Application of parallel computing to seismic damage process simulation of an arch dam

    NASA Astrophysics Data System (ADS)

    Zhong, Hong; Lin, Gao; Li, Jianbo

    2010-06-01

    The simulation of damage process of high arch dam subjected to strong earthquake shocks is significant to the evaluation of its performance and seismic safety, considering the catastrophic effect of dam failure. However, such numerical simulation requires rigorous computational capacity. Conventional serial computing falls short of that and parallel computing is a fairly promising solution to this problem. The parallel finite element code PDPAD was developed for the damage prediction of arch dams utilizing the damage model with inheterogeneity of concrete considered. Developed with programming language Fortran, the code uses a master/slave mode for programming, domain decomposition method for allocation of tasks, MPI (Message Passing Interface) for communication and solvers from AZTEC library for solution of large-scale equations. Speedup test showed that the performance of PDPAD was quite satisfactory. The code was employed to study the damage process of a being-built arch dam on a 4-node PC Cluster, with more than one million degrees of freedom considered. The obtained damage mode was quite similar to that of shaking table test, indicating that the proposed procedure and parallel code PDPAD has a good potential in simulating seismic damage mode of arch dams. With the rapidly growing need for massive computation emerged from engineering problems, parallel computing will find more and more applications in pertinent areas.

  15. Carbon Dioxide in the Aortic Arch: Coronary Effects and Implications in a Swine Study

    SciTech Connect

    Culp, William C. Porter, Thomas R.; Culp, William C.; Vonk, Brian N.

    2003-04-15

    Purpose: CO{sub 2} angiography is considered dangerous in the aortic arch where bubbles may cause critical cerebral and cardiac ischemia. We investigated CO{sub 2}distribution, physiologic effects in the heart, methods of detection and treatments. Methods: Eight pigs had CO{sub 2}and iodinated contrast arch angiograms in supine and both lateral decubitus positions. An electrocardiogram, physiologic data and cardiac ultrasound were obtained. Therapies included precordial thumps and rolls to lateral decubitus positions. Results: Supine high descending aorta CO{sub 2} injections floated retrograde up the arch during diastole and preferentially filled the right coronary artery (RCA): mean score 3.5 (of 4), in nominate artery 2.4, left coronary artery 1.2; n = 17; p = 0.0001. Aortic root injections preferentially filled the RCA when the animal was supine, left coronary in the right decubitus position, and showed a diffuse pattern in the left decubitus position. Right decubitus rolls filled both coronaries causing several lethal arrhythmias. Precordialthumps successfully cleared CO{sub 2}. Ultrasound is a sensitive detector of myocardial CO{sub 2}. Conclusion: Arch distribution of CO{sub 2} primarily involves the RCA. Diagnostic ultrasound detects cardiac CO{sub 2} well. Precordial thumps are an effective treatment.

  16. The impact of foot arch height on quality of life in 6-12 year olds

    PubMed Central

    Bouza Prego, Mª de los Ángeles; Requeijo Constenla, Ana; Saleta Canosa, Jesús Luis; Bautista Casasnovas, Adolfo; Tajes, Francisco Alonso

    2014-01-01

    Objective: To determine whether arch height has an effect on the health-related quality of life of schoolchildren. Methods: One hundred and thirteen schoolchildren attended an out-patient centre where self-reported data were recorded, their feet were classified into one of three groups according to their arch index (high, normal or low) and the scores obtained from the Foot Health Status Questionnaire (FHSQ - Spanish version) were compared. Results: The groups with high, low and normal arch recorded lower scores in Section One for the general foot health and footwear domains and higher scores in foot pain and foot function. In Section Two they obtained lower scores in general health and higher scores in physical activity, social capacity and vigour. Conclusions: Comparison of the scores obtained reveals that arch height has a negative impact on quality of life. Given the limited extent of available evidence in respect of the aetiology and treatment of foot diseases and deformities, these findings reveal the need to implement programmes to promote foot health and carry out further research into this commonly occurring disabling condition. PMID:25767305

  17. Persistent median artery in the carpal tunnel and anastomosis with superficial palmar arch.

    PubMed

    Bijannejad, Dariush; Azandeh, Saeed; Javadnia, Fatemeh; Gholami, Mohammad Reza; Gharravi, Anneh Mohammad; Zhaleh, Mohsen

    2016-01-01

    Persistent median artery (PMA) in present cadaver originated from the brachial artery and anastomosed with the superficial palmar arch (SPA). As the PMA may be the cause of carpal tunnel syndrome and SPA is the main source of arterial supply, knowledge of which are important for the hand surgical interventions. PMID:27583265

  18. Persistent median artery in the carpal tunnel and anastomosis with superficial palmar arch

    PubMed Central

    Bijannejad, Dariush; Azandeh, Saeed; Javadnia, Fatemeh; Gholami, Mohammad Reza; Gharravi, Anneh Mohammad; zhaleh, Mohsen

    2016-01-01

    Abstract Persistent median artery (PMA) in present cadaver originated from the brachial artery and anastomosed with the superficial palmar arch (SPA). As the PMA may be the cause of carpal tunnel syndrome and SPA is the main source of arterial supply, knowledge of which are important for the hand surgical interventions. PMID:27583265

  19. Multimodal optical measurement in vitro of surface deformations and wall thickness of the pressurized aortic arch.

    PubMed

    Genovese, Katia; Humphrey, Jay D

    2015-04-01

    Computational modeling of arterial mechanics continues to progress, even to the point of allowing the study of complex regions such as the aortic arch. Nevertheless, most prior studies assign homogeneous and isotropic material properties and constant wall thickness even when implementing patient-specific luminal geometries obtained from medical imaging. These assumptions are not due to computational limitations, but rather to the lack of spatially dense sets of experimental data that describe regional variations in mechanical properties and wall thickness in such complex arterial regions. In this work, we addressed technical challenges associated with in vitro measurement of overall geometry, full-field surface deformations, and regional wall thickness of the porcine aortic arch in its native anatomical configuration. Specifically, we combined two digital image correlation-based approaches, standard and panoramic, to track surface geometry and finite deformations during pressurization, with a 360-deg fringe projection system to contour the outer and inner geometry. The latter provided, for the first time, information on heterogeneous distributions of wall thickness of the arch and associated branches in the unloaded state. Results showed that mechanical responses vary significantly with orientation and location (e.g., less extensible in the circumferential direction and with increasing distance from the heart) and that the arch exhibits a nearly linear increase in pressure-induced strain up to 40%, consistent with other findings on proximal porcine aortas. Thickness measurements revealed strong regional differences, thus emphasizing the need to include nonuniform thicknesses in theoretical and computational studies of complex arterial geometries. PMID:25867620

  20. Effects of basilar membrane arch and radial tension on the travelling wave in gerbil cochlea.

    PubMed

    Chan, Wei Xuan; Yoon, Yong-Jin

    2015-09-01

    The basilar membrane velocity of gerbil cochlea showed discrepancy between theoretical model and experimental measurements. We hypothesize that the reasons of such discrepancies are due to the arch towards the scala tympani and radial tension present in the basilar membrane of the gerbil cochlea. The arch changes the bending stiffness in the basilar membrane, reduces the effective fluid force on the membrane and increases the basilar membrane's inertia. The existence of the radial tension also dampens the acoustic travelling wave. In this paper, the wave number functions along the gerbil basilar membrane are calculated from experimentally measured physical parameters with the theoretical model as well as extracted from experimentally measured basilar membrane velocity with the wave number inversion formula. The two wave number functions are compared and the effects of the tension and membrane arch on the wave number are studied based on various parameters of the model. We found that the bending stiffness across the gerbil basilar membrane varies (1-2 orders along the cochlea in the section 2.2 mm-3 mm from base) more than the calculated value in the flat basilar membrane model and the radial tension increases the damping of the travelling wave in gerbil cochlea significantly (5 times more than that without radial tension). These effects of arch and radial tension in the basilar membrane elucidate the discrepancy between previous theoretical model and experimental measurements in gerbil cochlea. PMID:26070425

  1. Prenatal diagnosis of the rare association of common arterial trunk and double aortic arch.

    PubMed

    Rock, Andrea; Eltayeb, Osama; Camarda, Joseph; Gotteiner, Nina

    2016-07-01

    Common arterial trunk with associated double aortic arch is a very rare constellation of congenital heart disease. Prenatal diagnosis allows for surgical repair prior to development of respiratory morbidity, which is otherwise described in all cases with this association. PMID:27386125

  2. Digital-image analysis of the aortic arch's development and its variations.

    PubMed

    Gielecki, Jerzy St; Wilk, Renata; Syc, Bozena; Musiał-Kopiejka, Magdalena; Piwowarczyk-Nowak, Aneta

    2004-11-01

    The study was performed on 103 human foetuses (58 female, 45 male) spontaneously aborted at between 14 and 30 weeks of gestation. The arteries were filled with latex, preserved in formalin and then dissected under the microscope and digitalised using a camera system. The following measurements were taken with the use of special computer software: the external diameter, the length and the volume of the arch of the aorta. The increase in diameter and length in relation to age corresponded to a linear function with values ranging from 1.77 mm to 4.09 mm for the diameter and from 4.94 mm to 13.31 mm for the length. The increase in volume corresponded to a square root function with values ranging from 13.42 mm3 to 173.96 mm3. Analysis of arch of the aorta variations revealed 11 cases of a common trunk for the brachiocephalic trunk and the left common carotid artery and 7 cases with the left vertebral artery arising directly from the arch of the aorta. In 2 cases the brachiocephalic trunk was absent, the right subclavian artery branching directly from the arch of the aorta at the level of the left subclavian artery or from the descending aorta just below the arterial duct ostium. PMID:15712142

  3. Rhinometric evaluation of nasal cavity geometry and its relation to the upper arch transverse distance.

    PubMed

    Paiva, João Batista; Alves, Adriana Silva; Ribeiro, Annelise Nazareth Cunha; Rino Neto, José; Fantini, Solange Mongeli de

    2009-01-01

    The objective of this study was to evaluate children's respiratory patterns in the mixed dentition, by means of acoustic rhinometry, and its relation to the upper arch width development. Fifty patients were examined, 25 females and 25 males with mean age of eight years and seven months. All of them were submitted to acoustic rhinometry and upper and lower arch impressions to obtain plaster models. The upper arch analysis was accomplished by measuring the interdental transverse distance of the upper teeth, deciduous canines (measurement 1), deciduous first molars (measurement 2), deciduous second molars (measurement 3) and the first molars (measurement 4). The results showed that an increased left nasal cavity area in females means an increased interdental distance of the deciduous first molars and deciduous second molars and an increased interdental distance of the deciduous canines, deciduous first and second molars in males. It was concluded that there is a correlation between the nasal cavity area and the upper arch transverse distance in the anterior and mid maxillary regions for both genders. PMID:20027450

  4. C1 anterior arch preservation in transnasal odontoidectomy using three-dimensional endoscope: A case report

    PubMed Central

    Zenga, Francesco; Marengo, Nicola; Pacca, Paolo; Pecorari, Giancarlo; Ducati, Alessandro

    2015-01-01

    Background: The transoral ventral corridor is the most common approach used to reach the craniovertebral junction (CVJ). Over the last decade, many case reports have demonstrated the transnasal corridor to the odontoid peg represents a practicable route to remove the tip of the odontoid process. The biomechanical consequences of the traditional odontoidectomy led to the necessity of a cervical spine stabilization. Preserving the inferior portion of the C1 anterior arch should prevent instability. Case Description: This is the first report in which the technique to remove the tip of the odontoid while preserving the C1 anterior arch is described by means of a three-dimensional (3D) endoscope. A 53-year-old man underwent a transnasal 3D endoscopic approach because of a complex CVJ malformation. The upper-medial portion of the C1 anterior arch was removed preserving its continuity, and the odontoidectomy was performed. After surgery, a dynamic X-ray scan showed no difference in CVJ motility in comparison with the preoperative one. Conclusions: The stereoscopic perception augmented the precision of the surgical gesture in the deep field. The importance of a 3D view relates to the depth of field, which a two-dimensional endoscopy cannot provide. This affects the preservation of the C1 anterior arch because of the presence of critical structures that are exposed to potential damage if not displayed. PMID:26759737

  5. Fibrous illite controls productivity in frontier gas sandstones, Moxa Arch, Wyoming

    SciTech Connect

    Luffel, D.L. ); Herrington. K.L. ); Harrison, C.W. )

    1992-12-01

    This paper reports that core, log, and well-test analyses from two wells recently completed in the Frontier sandstone in the Moxa Arch area of Wyoming revealed that fibrous illite severely reduced gas productivity. In this study area, presence of fibrous illite currently cannot be predicted and effects can be recognized only through laboratory tests on preserved cores.

  6. 25. 'DetailsTransverse Sections For Three Hinged Arch Bridge Over Yuba ...

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

    25. 'Details--Transverse Sections For Three Hinged Arch Bridge Over Yuba River At Parks Bar, Thomas System, Thomas And Post-- Consulting Engineers--Los Angeles.' Revised plans, but date of revision not legible. - Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

  7. 13. Detail of abutment/arch rib juncture. Northeast end of bridge, ...

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

    13. Detail of abutment/arch rib juncture. Northeast end of bridge, looking east to west. - Presumpscot Falls Bridge, Spanning Presumptscot River at Allen Avenue extension, 0.75 mile west of U.S. Interstate 95, Falmouth, Cumberland County, ME

  8. The seismic response of concrete arch bridges (with focus on the Bixby Creek bridge Carmel, California)

    SciTech Connect

    Hoehler, M; McCallen, D; Noble, C

    1999-06-01

    The analysis, and subsequent retrofit, of concrete arch bridges during recent years has relied heavily on the use of computational simulation. For seismic analysis in particular, computer simulation, typically utilizing linear approximations of structural behavior, has become standard practice. This report presents the results of a comprehensive study of the significance of model sophistication (i.e. linear vs. nonlinear) and pertinent modeling assumptions on the dynamic response of concrete arch bridges. The study uses the Bixby Creek Bridge, located in California, as a case study. In addition to presenting general recommendations for analysis of this class of structures, this report provides an independent evaluation of the proposed seismic retrofit for the Bixby Creek Bridge. Results from the study clearly illustrate a reduction of displacement drifts and redistribution of member forces brought on by the inclusion of material nonlinearity. The analyses demonstrate that accurate modeling of expansion joints, for the Bixby Creek Bridge in particular, is critical to achieve representative modal and transient behavior. The inclusion of near-field displacement pulses in ground motion records was shown to significantly increase demand on the relatively softer, longer period Bixby Creek Bridge arch. Stiffer, shorter period arches, however, are more likely susceptible to variable support motions arising from the canyon topography typical for this class of bridges.

  9. Individual tooth macrowear pattern guides the reconstruction of Sts 52 (Australopithecus africanus) dental arches.

    PubMed

    Benazzi, Stefano; Kullmer, Ottmar; Schulz, Dieter; Gruppioni, Giorgio; Weber, Gerhard W

    2013-02-01

    The functional restoration of the occlusal relationship between maxillary and mandibular tooth rows is a major challenge in modern dentistry and maxillofacial surgery. Similar technical challenges are present in paleoanthropology when considering fragmented and deformed mandibular and maxillary fossils. Sts 52, an Australopithecus africanus specimen from Sterkfontein Member 4, represents a typical case where the original shape of the dental arches is no longer preserved. It includes a partial lower face (Sts 52a) and a fragmented mandible (Sts 52b), both incomplete and damaged to such an extent to thwart attempts at matching upper and lower dentitions. We show how the preserved macro wear pattern of the tooth crowns can be used to functionally reconstruct Sts 52's dental arches. High-resolution dental stone casts of Sts 52 maxillary and mandibular dentition were mounted and repositioned in a dental articulator. The occlusal relationship between antagonists was restored based on the analysis of the occlusal wear pattern of each preserved tooth, considering all dental contact movements represented in the occlusal compass. The reconstructed dental arches were three-dimensional surface scanned and their occlusal kinematics tested in a simulation. The outcome of this contribution is the first functional restoration of A. africanus dental arches providing new morphometric data for specimen Sts 52. It is noteworthy that the method described in this case study might be applied to several other fossil specimens. PMID:23296796

  10. The Mtr4 ratchet helix and arch domain both function to promote RNA unwinding.

    PubMed

    Taylor, Lacy L; Jackson, Ryan N; Rexhepaj, Megi; King, Alejandra Klauer; Lott, Lindsey K; van Hoof, Ambro; Johnson, Sean J

    2014-12-16

    Mtr4 is a conserved Ski2-like RNA helicase and a subunit of the TRAMP complex that activates exosome-mediated 3'-5' turnover in nuclear RNA surveillance and processing pathways. Prominent features of the Mtr4 structure include a four-domain ring-like helicase core and a large arch domain that spans the core. The 'ratchet helix' is positioned to interact with RNA substrates as they move through the helicase. However, the contribution of the ratchet helix in Mtr4 activity is poorly understood. Here we show that strict conservation along the ratchet helix is particularly extensive for Ski2-like RNA helicases compared to related helicases. Mutation of residues along the ratchet helix alters in vitro activity in Mtr4 and TRAMP and causes slow growth phenotypes in vivo. We also identify a residue on the ratchet helix that influences Mtr4 affinity for polyadenylated substrates. Previous work indicated that deletion of the arch domain has minimal effect on Mtr4 unwinding activity. We now show that combining the arch deletion with ratchet helix mutations abolishes helicase activity and produces a lethal in vivo phenotype. These studies demonstrate that the ratchet helix modulates helicase activity and suggest that the arch domain plays a previously unrecognized role in unwinding substrates. PMID:25414331

  11. Intrinsic foot muscles have the capacity to control deformation of the longitudinal arch

    PubMed Central

    Kelly, Luke A.; Cresswell, Andrew G.; Racinais, Sebastien; Whiteley, Rodney; Lichtwark, Glen

    2014-01-01

    The human foot is characterized by a pronounced longitudinal arch (LA) that compresses and recoils in response to external load during locomotion, allowing for storage and return of elastic energy within the passive structures of the arch and contributing to metabolic energy savings. Here, we examine the potential for active muscular contribution to the biomechanics of arch deformation and recoil. We test the hypotheses that activation of the three largest plantar intrinsic foot muscles, abductor hallucis, flexor digitorum and quadratus plantae is associated with muscle stretch in response to external load on the foot and that activation of these muscles (via electrical stimulation) will generate sufficient force to counter the deformation of LA caused by the external load. We found that recruitment of the intrinsic foot muscles increased with increasing load, beyond specific load thresholds. Interestingly, LA deformation and muscle stretch plateaued towards the maximum load of 150% body weight, when muscle activity was greatest. Electrical stimulation of the plantar intrinsic muscles countered the deformation that occurred owing to the application of external load by reducing the length and increasing the height of the LA. These findings demonstrate that these muscles have the capacity to control foot posture and LA stiffness and may provide a buttressing effect during foot loading. This active arch stiffening mechanism may have important implications for how forces are transmitted during locomotion and postural activities as well as consequences for metabolic energy saving. PMID:24478287

  12. Analysis of Yielding Steel Arch Support with Rock Bolts in Mine Roadways Stability Aspect

    NASA Astrophysics Data System (ADS)

    Majcherczyk, Tadeusz; Niedbalski, Zbigniew; Małkowski, Piotr; Bednarek, łukasz

    2014-10-01

    The result of the search for new technological solutions in the field of support for roadways in coal mines has in recent years been the widespread use of steel arch with rockbolt support systems. The efficiency of these systems is affected among other things by the option of installing rock bolts after the actual driving the mine roadway, the increased load capacity that these systems can support, and their resistance to dynamic weight. Large variation in the way that these steel arch support can be connected using different types of rock bolts necessitates mining research revealing the effectiveness of such solutions. Although the steel arch with rockbolt support system is used in the majority of European coal mines, it is still not possible to apply templates of schemes due to the diversity of geological and mining conditions. Therefore, throughout a period of several years, the authors of this article conducted research in situ under conditions of different schemes related to connecting arched support frames with rock bolts, with only selected results being presented in the article. The measurements of convergence, load supported by the system frame, load supported by the rock bolts, and the stratification of roof rocks were analyzed, carried out in two roadways with yielding steel arch support in which strand bolts were applied. The article also proposes the index for working maintenance nuw, used in preliminarily assessing the stability of a given working with a limited number of data concerning geomechanical conditions. Additionally considered are empirical methods used in Poland for designing steel arch with rock bolt support systems. The results of mine research indicate that strengthening yielding steel support with strand bolts through steel beams maintains the stability of a roadway, even when exposed to the exploitation stress. Aside from the impact of exploitation, deformations of the support system are negligible, despite the fact that the tensile

  13. Biological arches and changes to the curvilinear form of the aging maxilla.

    PubMed

    Zadoo, V P; Pessa, J E

    2000-08-01

    The facial skeleton can be conceptualized as a series of arches aligned along a vertical axis, with regional differences in shape. Previous work suggested that the maxilla undergoes differential growth with time. Because these arch forms resemble geometric forms, it may be possible to measure changes to their shape with the aging process. A contour analysis of the aging maxilla was undertaken. Computed tomographic data were assembled retrospectively. Only men were studied, and they were divided into two groups: young (aged 18 to 24 years; n = 6) and old (aged 40 to 66 years; n = 6). The computed tomography data were reconstructed into three-dimensional images and underwent standardization for comparison purposes. An axial view of the maxilla along the Frankfort horizontal was used for analysis. To quantify changes between curves, measurements were made of the vertical distance from eight equidistant points along each curve perimeter to a standardized baseline. Average arch forms for young and old men were then generated for comparison purposes. Each of the eight points along the older maxillary arch form existed further from the baseline than the younger arch form. This difference reached statistical significance at three of the eight points measured along the two curves. The greatest difference occurred at point 8 (p = .0006), which was at the medial maxilla near the nasomaxillary junction. The results of the study suggest that the actual contour of the maxilla undergoes changes as a result of the aging process. Mathematically defined idealized skeletal contours could help guide reconstructive surgery and aesthetic augmentation of the facial skeleton in the future. In addition, certain soft tissues of the face and torso seem to share a common shape (an alpha contour). This shape may also exhibit idealized forms open to quantitative analysis. The skeletal arch form and alpha contour most likely exhibit sexual dimorphism and will require further investigation. The

  14. Total Aortic Arch Replacement: Superior Ventriculo-Arterial Coupling with Decellularized Allografts Compared with Conventional Prostheses

    PubMed Central

    Schmack, Bastian; Korkmaz, Sevil; Li, Shiliang; Chaimow, Nicole; Pätzold, Ines; Becher, Peter Moritz; Hartyánszky, István; Soós, Pál; Merkely, Gergő; Németh, Balázs Tamás; Istók, Roland; Veres, Gábor; Merkely, Béla; Terytze, Konstantin; Karck, Matthias; Szabó, Gábor

    2014-01-01

    Background To date, no experimental or clinical study provides detailed analysis of vascular impedance changes after total aortic arch replacement. This study investigated ventriculoarterial coupling and vascular impedance after replacement of the aortic arch with conventional prostheses vs. decellularized allografts. Methods After preparing decellularized aortic arch allografts, their mechanical, histological and biochemical properties were evaluated and compared to native aortic arches and conventional prostheses in vitro. In open-chest dogs, total aortic arch replacement was performed with conventional prostheses and compared to decellularized allografts (n = 5/group). Aortic flow and pressure were recorded continuously, left ventricular pressure-volume relations were measured by using a pressure-conductance catheter. From the hemodynamic variables end-systolic elastance (Ees), arterial elastance (Ea) and ventriculoarterial coupling were calculated. Characteristic impedance (Z) was assessed by Fourier analysis. Results While Ees did not differ between the groups and over time (4.1±1.19 vs. 4.58±1.39 mmHg/mL and 3.21±0.97 vs. 3.96±1.16 mmHg/mL), Ea showed a higher increase in the prosthesis group (4.01±0.67 vs. 6.18±0.20 mmHg/mL, P<0.05) in comparison to decellularized allografts (5.03±0.35 vs. 5.99±1.09 mmHg/mL). This led to impaired ventriculoarterial coupling in the prosthesis group, while it remained unchanged in the allograft group (62.5±50.9 vs. 3.9±23.4%). Z showed a strong increasing tendency in the prosthesis group and it was markedly higher after replacement when compared to decellularized allografts (44.6±8.3dyn·sec·cm−5 vs. 32.4±2.0dyn·sec·cm−5, P<0.05). Conclusions Total aortic arch replacement leads to contractility-afterload mismatch by means of increased impedance and invert ventriculoarterial coupling ratio after implantation of conventional prostheses. Implantation of decellularized allografts preserves vascular impedance

  15. Results with an Algorithmic Approach to Hybrid Repair of the Aortic Arch

    PubMed Central

    Andersen, Nicholas D.; Williams, Judson B.; Hanna, Jennifer M.; Shah, Asad A.; McCann, Richard L.; Hughes, G. Chad

    2013-01-01

    Objective Hybrid repair of the transverse aortic arch may allow for aortic arch repair with reduced morbidity in patients who are suboptimal candidates for conventional open surgery. Here, we present our results with an algorithmic approach to hybrid arch repair, based upon the extent of aortic disease and patient comorbidities. Methods Between August 2005 and January 2012, 87 patients underwent hybrid arch repair by three principal procedures: zone 1 endograft coverage with extra-anatomic left carotid revascularization (zone 1, n=19), zone 0 endograft coverage with aortic arch debranching (zone 0, n=48), or total arch replacement with staged stented elephant trunk completion (stented elephant trunk, n=20). Results The mean patient age was 64 years and the mean expected in-hospital mortality rate was 16.3% as calculated by the EuroSCORE II. 22% (n=19) of operations were non-elective. Sternotomy, cardiopulmonary bypass, and deep hypothermic circulatory arrest were required in 78% (n=68), 45% (n=39), and 31% (n=27) of patients, respectively, to allow for total arch replacement, arch debranching, or other concomitant cardiac procedures, including ascending ± hemi-arch replacement in 17% (n=8) of patients undergoing zone 0 repair. All stented elephant trunk procedures (n=20) and 19% (n=9) of zone 0 procedures were staged, with 41% (n=12) of patients undergoing staged repair during a single hospitalization. The 30-day/in-hospital rates of stroke and permanent paraplegia/paraparesis were 4.6% (n=4) and 1.2% (n=1), respectively. Three of 27 (11.1%) patients with native ascending aorta zone 0 proximal landing zone experienced retrograde type A dissection following endograft placement. The overall in-hospital mortality rate was 5.7% (n=5), however, 30-day/in-hospital mortality increased to 14.9% (n=13) due to eight 30-day out-of-hospital deaths. Native ascending aorta zone 0 endograft placement was found to be the only univariate predictor of 30-day/in-hospital mortality

  16. Morphodynamic equilibrium of alluvial estuaries

    NASA Astrophysics Data System (ADS)

    Tambroni, Nicoletta; Bolla Pittaluga, Michele; Canestrelli, Alberto; Lanzoni, Stefano; Seminara, Giovanni

    2014-05-01

    The evolution of the longitudinal bed profile of an estuary, with given plan-form configuration, subject to given tidal forcing at the mouth and prescribed values of water and sediment supply from the river is investigated numerically. Our main goal is to ascertain whether, starting from some initial condition, the bed evolution tends to reach a unique equilibrium configuration asymptotically in time. Also, we investigate the morphological response of an alluvial estuary to changes in the tidal range and hydrologic forcing (flow and sediment supply). Finally, the solution helps characterizing the transition between the fluvially dominated region and the tidally dominated region of the estuary. All these issues play an important role also in interpreting how the facies changes along the estuary, thus helping to make correct paleo-environmental and sequence-stratigraphic interpretations of sedimentary successions (Dalrymple and Choi, 2007). Results show that the model is able to describe a wide class of settings ranging from tidally dominated estuaries to fluvially dominated estuaries. In the latter case, the solution is found to compare satisfactory with the analytical asymptotic solution recently derived by Seminara et al. (2012), under the hypothesis of fairly 'small' tidal oscillations. Simulations indicate that the system always moves toward an equilibrium configuration in which the net sediment flux in a tidal cycle is constant throughout the estuary and equal to the constant sediment flux discharged from the river. For constant width, the bed equilibrium profile of the estuarine channel is characterized by two distinct regions: a steeper reach seaward, dominated by the tide, and a less steep upstream reach, dominated by the river and characterized by the undisturbed bed slope. Although the latter reach, at equilibrium, is not directly affected by the tidal wave, however starting from an initial uniform stream with the constant 'fluvial' slope, the final

  17. When and how to replace the aortic arch for type A dissection.

    PubMed

    Di Bartolomeo, Roberto; Leone, Alessandro; Di Marco, Luca; Pacini, Davide

    2016-07-01

    Acute type A aortic dissection (AAAD) remains one of the most challenging diseases in cardiothoracic surgery and despite numerous innovations in medical and surgical management, early mortality remains high. The standard treatment of AAAD requires emergency surgery of the proximal aorta, preventing rupture and consequent cardiac tamponade. Resection of the primary intimal tear and repair of the aortic root and aortic valve are well-established surgical principles. However, the dissection in the aortic arch and descending untreated aorta remains. This injury is associated with the risk of subsequent false lumen dilatation potentially progressing to rupture, true lumen compression and distal malperfusion. Additionally, the dilatation of the aortic arch, the presence of a tear and retrograde dissection can all be considered indication for a total arch replacement in AAAD. In such cases a more aggressive strategy may be used, from the classic aortic arch operation to a single stage frozen elephant trunk (FET) technique or a two-stage approach such as the classical elephant trunk (ET) or the recent Lupiae technique. Although these are all feasible solutions, they are also complex and time demanding techniques requiring experience and expertise, with an in the length of cardiopulmonary bypass and both myocardial and visceral ischemia. Effective methods of cerebral, myocardial as well visceral protection are necessary to obtain acceptable results in terms of hospital mortality and morbidity. Moreover, a correct assessment of the anatomy of the dissection, through the preoperative angio CT scan, in addition to the clinical condition of the patients, remain the decision points for the best arch repair strategy to use in AAAD. PMID:27563552

  18. Open Aortic Arch Reconstruction After Coronary Artery Bypass Surgery: Worth the Effort?

    PubMed

    Quintana, Eduard; Bajona, Pietro; Schaff, Hartzell V; Dearani, Joseph A; Daly, Richard; Greason, Kevin; Pochettino, Alberto

    2016-01-01

    Open aortic arch surgery after coronary artery bypass grafting (CABG) is considered a high-risk operation. We reviewed our surgical approach and outcomes to establish the risk profile for this patient population. In methods, from 2000-2014, 650 patients underwent aortic arch surgery with circulatory arrest. Of these, 45 (7%) had previous CABG. Complete medical record was available for review including all preoperative coronary angiograms and detailed management of myocardial protection. In results, the mean interval from previous CABG to aortic arch surgery was 6.8 ± 7.1 years. At reoperation, 33 (73%) patients had hemiarch replacement and 12 (27%) had a total arch replacement. The following were the indications for surgery: fusiform aneurysm in 20 (44%), pseudoaneurysm in 6 (13%), endocarditis in 4 (9%), valvular disease in 5 (11%), and acute aortic dissection in 10 (22%). There were 6 perioperative deaths (13%) and 1 stroke (2.2%). Selective antegrade cerebral perfusion was used in 13 patients (28.9%) and retrograde perfusion in 6 (13.3%). Survival was 74%, 65%, and 52% at 1, 3, and 5-year follow-up, respectively. Only predictors of early mortality were age (odds ratio = 1.20, CI: 1.01-1.44; P = 0.04) and nonuse of retrograde cardioplegia for myocardial protection (odds ratio = 6.80, CI: 1.06-43.48; P = 0.04). Intermediate survival of these patients was significantly lower than those of a sex-matched and age-matched population (P < 0.001). In conclusion, aortic arch surgery after previous CABG can be performed with acceptable early and midterm results and low risk of stroke. Perfusion strategies and myocardial protection contribute to successful outcomes. PMID:27568130

  19. When and how to replace the aortic arch for type A dissection

    PubMed Central

    Leone, Alessandro; Di Marco, Luca; Pacini, Davide

    2016-01-01

    Acute type A aortic dissection (AAAD) remains one of the most challenging diseases in cardiothoracic surgery and despite numerous innovations in medical and surgical management, early mortality remains high. The standard treatment of AAAD requires emergency surgery of the proximal aorta, preventing rupture and consequent cardiac tamponade. Resection of the primary intimal tear and repair of the aortic root and aortic valve are well-established surgical principles. However, the dissection in the aortic arch and descending untreated aorta remains. This injury is associated with the risk of subsequent false lumen dilatation potentially progressing to rupture, true lumen compression and distal malperfusion. Additionally, the dilatation of the aortic arch, the presence of a tear and retrograde dissection can all be considered indication for a total arch replacement in AAAD. In such cases a more aggressive strategy may be used, from the classic aortic arch operation to a single stage frozen elephant trunk (FET) technique or a two-stage approach such as the classical elephant trunk (ET) or the recent Lupiae technique. Although these are all feasible solutions, they are also complex and time demanding techniques requiring experience and expertise, with an in the length of cardiopulmonary bypass and both myocardial and visceral ischemia. Effective methods of cerebral, myocardial as well visceral protection are necessary to obtain acceptable results in terms of hospital mortality and morbidity. Moreover, a correct assessment of the anatomy of the dissection, through the preoperative angio CT scan, in addition to the clinical condition of the patients, remain the decision points for the best arch repair strategy to use in AAAD. PMID:27563552

  20. A review of the surgical management of right-sided aortic arch aneurysms.

    PubMed

    Barr, James G; Sepehripour, Amir H; Jarral, Omar A; Tsipas, Pantelis; Kokotsakis, John; Kourliouros, Antonios; Athanasiou, Thanos

    2016-07-01

    Aneurysms and dissections of the right-sided aortic arch are rare and published data are limited to a few case reports and small series. The optimal treatment strategy of this entity and the challenges associated with their management are not yet fully investigated and conclusive. We performed a systematic review of the literature to identify all patients who underwent surgical or endovascular intervention for right aortic arch aneurysms or dissections. The search was limited to the articles published only in English. We focused on presentation and critically assessed different management strategies and outcomes. We identified 74 studies that reported 99 patients undergoing surgical or endovascular intervention for a right aortic arch aneurysm or dissection. The median age was 61 years. The commonest presenting symptoms were chest or back pain and dysphagia. Eighty-eight patients had an aberrant left subclavian artery with only 11 patients having the mirror image variant of a right aortic arch. The commonest pathology was aneurysm arising from a Kommerell's diverticulum occurring in over 50% of the patients. Twenty-eight patients had dissections, 19 of these were Type B and 9 were Type A. Eighty-one patients had elective operations while 18 had emergency procedures. Sixty-seven patients underwent surgical treatment, 20 patients had hybrid surgical and endovascular procedures and 12 had totally endovascular procedure. There were 5 deaths, 4 of which were in patients undergoing emergency surgery and none in the endovascular repair group. Aneurysms and dissections of a right-sided aortic arch are rare. Advances in endovascular treatment and hybrid surgical and endovascular management are making this rare pathology amenable to these approaches and may confer improved outcomes compared with conventional extensive repair techniques. PMID:27001673

  1. Ideal or Young-Looking Brow Height and Arch Shape Preferred by Koreans.

    PubMed

    Hwang, Se Jin; Kim, Hun; Hwang, Kun; Kim, Seong Kee; Kim, Young Suk; Kim, Yeon Soo

    2015-07-01

    The aim of this study is to see which brow height and arch shape is preferred as ideal or young-looking by Koreans. A survey was conducted between June and Dec 2014 on 186 women who visited the brow bar ("Benefit" of Incheon city). They were asked to choose which they believed ideal and youngest amongst the 3 brow archetypes according to their height and 4 types of modification of Anastasia (rotation of medial and lateral arms), which was illustrated. Approximately half (52.5%) of the respondents answered that their brow matches them very well or well. Most (81.2%) believed there might be a method to yield an ideal brow archetype and almost all (97.3%) would change the brow shape if the expert advised. The most preferred ideal brow height was of a middle height (63.2%, the distance from the lateral canthus to the lateral end of eyebrow, which was 2/3 of the eye width). The most preferred ideal brow arch shape was the arched type (57.6% arches on a line drawn from the center of the nose through the center of the pupil). The most preferred young-looking brow height was of an upper height (46.2%, the distance from the lateral canthus to the lateral end of eyebrow was 3/4 of the eye width) followed by a middle height (39.7%). The most preferred young-looking brow arch shape was the head-up position (53.3%, medial arm of the brow was rotated upward to the horizontal plane). The result of this study might be useful in facial rejuvenation surgeries as well as in brow esthetics or tattooing of the eyebrows. PMID:26167996

  2. Morphogenesis of the human palma arch using three-dimensional geometric modeling.

    PubMed

    Durand, Sebastien; Marin, Frederic; Oberlin, Christophe; Ho Ba Tho, Marie-Christine

    2011-10-01

    The hand goes through complex morphological modifications during embryogenesis. The goal of this study was to use geometric modeling to study the morphometric modifications of the palmar arch. Five embryos were used for the study (sizes: 15, 17, 23, 30, and 44 mm). After digitalization of histologic sections (Sony DXC-930P 3CCD camera, Leica Qwin) and segmentation of the metacarpal cartilaginous matrices (Winsurf 4.3 software), geometric modeling and calculations were performed using MSC.Patran 2005r2 software. Correlations (r > 0.99) were found between embryo size and metacarpal volume, metacarpal surface, and the surface of the modeled palmar arch. The growth of the palmar arch is nonhomothetic. Significant reduction (P = 0.05) in the divergence of the 2nd, 3rd, 4th, and 5th metacarpals was observed. Deepening of the palmar arch is correlated with embryo size and age (r > 0.99). Geometric modeling allows 3D rendering of histologic sections and thus quantitative description of the morphogenesis. The results of this study support the hypothesis that opposition of the thumb in correlation with deepening of the palmar arch appears early in embryological development. It constitutes a specific morphological characteristic that appears very early in the human phylum. The fact that the human thumb is naturally in opposition in the resting position is a consequence of this morphogenesis. The thumb's resting position has received little attention in clinical settings and should be considered as the reference position for biomechanical analysis of the thumb column. PMID:21538563

  3. Feasibility study on the application of fenestrated stent grafts in canine aortic arches

    PubMed Central

    Xi, Er-Ping; Zhu, Jian; Zhu, Shui-Bo; Zhang, Yu; Xu, Gui-Hua

    2015-01-01

    Objective: To validate the feasibility and effectiveness of applying fenestrated stent grafts in canine aortic arches. Methods: According to the anatomic characteristics of the aortic arches from four adult beagle dogs, a straight-type aortic coated vascular stent system from Lifetech Scientific (Shenzhen) Co., Ltd. was released in vitro, after which a square window was burnt out at the back tendon of the coated vascular stent with an electrocautery pen, and the fenestrated stent grafts were then returned in the catheter and delivery sheath, following the original release path. Endovascular aortic repair (EVAR) was then performed in the canine aorta. Immediately after surgery, digital subtraction angiography (DSA) and computed tomography (CT) angiography were conducted. On day 3, the dressing was changed, and on day 7, the stitches were removed and CT angiography was reviewed. Animal autopsies were performed 2 weeks after surgery. Results: DSA and CT angiography were conducted in 4 beagles immediately after the experiments. The CT angiography reviewed on day 7 after surgery and the animal autopsy performed two weeks after surgery both revealed that the fenestrated stent grafts were anchored in the canine aortic arch, the openings were aligned against the branch vessels above the aortic arch, and in each branch vessel, the blood flow was smooth, without any obvious internal leakage phenomena. Conclusion: An ordinary straight-type coated vascular stent, fenestrated in vitro, followed by the performance of EVAR in the canine aortic arch for in vivo stent implantation, was technically feasible. When a branch coated vascular stent cannot meet the individual needs of the wound, this technology may provide a valuable strategy for clinical thoracic aortic trauma emergencies. PMID:25785052

  4. In Vitro Hemodynamic Investigation of the Embryonic Aortic Arch at Late Gestation

    PubMed Central

    Pekkan, Kerem; Dasi, Lakshmi P.; Nourparvar, Paymon; Yerneni, Srinivasu; Tobita, Kimimasa; Fogel, Mark A.; Keller, Bradley; Yoganathan, Ajit

    2013-01-01

    This study focuses on the dynamic flow through the fetal aortic arch driven by the concurrent action of right and left ventricles. We created a parametric pulsatile computational fluid dynamics (CFD) model of the fetal aortic junction with physiologic vessel geometries. To gain a better biophysical understanding an in vitro experimental fetal flow loop for flow visualization was constructed for identical CFD conditions. CFD and in vitro experimental results were comparable. Swirling flow during the acceleration phase of the cardiac cycle and unidirectional flow following mid-deceleration phase were observed in pulmonary arteries (PA), head-neck vessels, and descending aorta. Right-to-left (oxygenated) blood flowed through the ductus arteriosus (DA) posterior relative to the antegrade left ventricular outflow tract (LVOT) stream and resembled jet flow. LVOT and right ventricular outflow tract flow mixing had not completed until ~3.5 descending aorta diameters downstream of the DA insertion into the aortic arch. Normal arch model flow patterns were then compared to flow patterns of four common congenital heart malformations that include aortic arch anomalies. Weak oscillatory reversing flow through the DA junction was observed only for the Tetralogy of Fallot configuration. Pulmonary Atresia and Hypoplastic Left Heart Syndrome configurations demonstrated complex, abnormal flow patterns in the PAs and head-neck vessels. Aortic Coarctation resulted in large scale recirculating flow in the aortic arch proximal to the DA. Intravascular flow patterns spatially correlated with abnormal vascular structures consistent with the paradigm that abnormal intravascular flow patterns associated with congenital heart disease influence vascular growth and function. PMID:18466908

  5. Torque equilibrium attitude control for Skylab reentry

    NASA Technical Reports Server (NTRS)

    Glaese, J. R.; Kennel, H. F.

    1979-01-01

    All the available torque equilibrium attitudes (most were useless from the standpoint of lack of electrical power) and the equilibrium seeking method are presented, as well as the actual successful application during the 3 weeks prior to Skylab reentry.

  6. Estimating long-run equilibrium real exchange rates: short-lived shocks with long-lived impacts on Pakistan.

    PubMed

    Zardad, Asma; Mohsin, Asma; Zaman, Khalid

    2013-12-01

    The purpose of this study is to investigate the factors that affect real exchange rate volatility for Pakistan through the co-integration and error correction model over a 30-year time period, i.e. between 1980 and 2010. The study employed the autoregressive conditional heteroskedasticity (ARCH), generalized autoregressive conditional heteroskedasticity (GARCH) and Vector Error Correction model (VECM) to estimate the changes in the volatility of real exchange rate series, while an error correction model was used to determine the short-run dynamics of the system. The study is limited to a few variables i.e., productivity differential (i.e., real GDP per capita relative to main trading partner); terms of trade; trade openness and government expenditures in order to manage robust data. The result indicates that real effective exchange rate (REER) has been volatile around its equilibrium level; while, the speed of adjustment is relatively slow. VECM results confirm long run convergence of real exchange rate towards its equilibrium level. Results from ARCH and GARCH estimation shows that real shocks volatility persists, so that shocks die out rather slowly, and lasting misalignment seems to have occurred. PMID:23853758

  7. A quantitative method for defining high-arched palate using the Tcof1(+/-) mutant mouse as a model.

    PubMed

    Conley, Zachary R; Hague, Molly; Kurosaka, Hiroshi; Dixon, Jill; Dixon, Michael J; Trainor, Paul A

    2016-07-15

    The palate functions as the roof of the mouth in mammals, separating the oral and nasal cavities. Its complex embryonic development and assembly poses unique susceptibilities to intrinsic and extrinsic disruptions. Such disruptions may cause failure of the developing palatal shelves to fuse along the midline resulting in a cleft. In other cases the palate may fuse at an arch, resulting in a vaulted oral cavity, termed high-arched palate. There are many models available for studying the pathogenesis of cleft palate but a relative paucity for high-arched palate. One condition exhibiting either cleft palate or high-arched palate is Treacher Collins syndrome, a congenital disorder characterized by numerous craniofacial anomalies. We quantitatively analyzed palatal perturbations in the Tcof1(+/-) mouse model of Treacher Collins syndrome, which phenocopies the condition in humans. We discovered that 46% of Tcof1(+/-) mutant embryos and new born pups exhibit either soft clefts or full clefts. In addition, 17% of Tcof1(+/-) mutants were found to exhibit high-arched palate, defined as two sigma above the corresponding wild-type population mean for height and angular based arch measurements. Furthermore, palatal shelf length and shelf width were decreased in all Tcof1(+/-) mutant embryos and pups compared to controls. Interestingly, these phenotypes were subsequently ameliorated through genetic inhibition of p53. The results of our study therefore provide a simple, reproducible and quantitative method for investigating models of high-arched palate. PMID:26772999

  8. Vertebrae in compression: Mechanical behavior of arches and centra in the gray smooth-hound shark (Mustelus californicus).

    PubMed

    Porter, Marianne E; Long, John H

    2010-03-01

    In swimming sharks, vertebrae are subjected, in part, to compressive loads as axial muscles contract. We currently have no information about which vertebral elements, centra, arch cartilages, or both, actually bear compressive loads in cartilaginous vertebrae. To address this issue, the goal of this experiment was to determine the load-bearing ability of arch and centrum cartilages in compression, to determine the material properties of shark vertebrae, and to document fracture patterns in the centra with and without the arches. Intact vertebrae and vertebrae with the arch cartilages experimentally removed (centra alone) were subjected to compressive loading to failure at a single strain rate. The maximum compressive forces sustained by the vertebrae and the centra are statistically indistinguishable. Thus we conclude that under these testing conditions the arch does not bear appreciable loads. Independent evidence for this conclusion comes from the fact that vertebrae fail in compression at the centra, and not at the arches. Overall, the results of these mechanical tests suggest that the neural arches are not the primary load-bearing structure during axial compression. PMID:19862836

  9. Three-dimensional dental arch changes of patients submitted to orthodontic-surgical treatment for correction of Class II malocclusion

    PubMed Central

    Peixoto, Adriano Porto; Pinto, Ary dos Santos; Garib, Daniela Gamba; Gonçalves, João Roberto

    2014-01-01

    Introduction This study assessed the three-dimensional changes in the dental arch of patients submitted to orthodontic-surgical treatment for correction of Class II malocclusions at three different periods. Methods Landmarks previously identified on upper and lower dental casts were digitized on a three-dimensional digitizer MicroScribe-3DX and stored in Excel worksheets in order to assess the width, length and depth of patient's dental arches. Results During orthodontic preparation, the maxillary and mandibular transverse dimensions measured at the premolar regions were increased and maintained throughout the follow-up period. Intercanine width was increased only in the upper arch during orthodontic preparation. Maxillary arch length was reduced during orthodontic finalization, only. Upper and lower arch depths were stable in the study periods. Differences between centroid and gingival changes suggested that upper and lower arch premolars buccaly proclined during the pre-surgical period. Conclusions Maxillary and mandibular dental arches presented transverse expansion at premolar regions during preoperative orthodontic preparation, with a tendency towards buccal tipping. The transverse dimensions were not altered after surgery. No sagittal or vertical changes were observed during the follow-up periods. PMID:25279524

  10. Open problems in non-equilibrium physics

    SciTech Connect

    Kusnezov, D.

    1997-09-22

    The report contains viewgraphs on the following: approaches to non-equilibrium statistical mechanics; classical and quantum processes in chaotic environments; classical fields in non-equilibrium situations: real time dynamics at finite temperature; and phase transitions in non-equilibrium conditions.

  11. Thermal equilibrium in Einstein's elevator.

    PubMed

    Sánchez-Rey, Bernardo; Chacón-Acosta, Guillermo; Dagdug, Leonardo; Cubero, David

    2013-05-01

    We report fully relativistic molecular-dynamics simulations that verify the appearance of thermal equilibrium of a classical gas inside a uniformly accelerated container. The numerical experiments confirm that the local momentum distribution in this system is very well approximated by the Jüttner function-originally derived for a flat spacetime-via the Tolman-Ehrenfest effect. Moreover, it is shown that when the acceleration or the container size is large enough, the global momentum distribution can be described by the so-called modified Jüttner function, which was initially proposed as an alternative to the Jüttner function. PMID:23767501

  12. Princeton spectral equilibrium code: PSEC

    SciTech Connect

    Ling, K.M.; Jardin, S.C.

    1984-03-01

    A fast computer code has been developed to calculate free-boundary solutions to the plasma equilibrium equation that are consistent with the currents in external coils and conductors. The free-boundary formulation is based on the minimization of a mean-square error epsilon while the fixed-boundary solution is based on a variational principle and spectral representation of the coordinates x(psi,theta) and z(psi,theta). Specific calculations using the Columbia University Torus II, the Poloidal Divertor Experiment (PDX), and the Tokamak Fusion Test Reactor (TFTR) geometries are performed.

  13. Conformations of Proteins in Equilibrium

    NASA Astrophysics Data System (ADS)

    Micheletti, Cristian; Banavar, Jayanth R.; Maritan, Amos

    2001-08-01

    We introduce a simple theoretical approach for an equilibrium study of proteins with known native-state structures. We test our approach with results on well-studied globular proteins, chymotrypsin inhibitor (2ci2), barnase, and the alpha spectrin SH3 domain, and present evidence for a hierarchical onset of order on lowering the temperature with significant organization at the local level even at high temperatures. A further application to the folding process of HIV-1 protease shows that the model can be reliably used to identify key folding sites that are responsible for the development of drug resistance.

  14. Comparative Finite Element Method Analysis of Spiroid Worm Gear Drives Having Arched Profile and Having Linear Profile in Axial Section

    NASA Astrophysics Data System (ADS)

    Bodzás, Sándor; Dudás, Illés

    2014-12-01

    With the knowledge of the advantageous characteristics of the cylindrical worm gear drives having arched profile in axial section and the conical worm gear drives having linear profile in axial section, a new geometric type conical worm gear drive has been designed and then manufactured, that is the conical worm gear drive having arched profile in axial section. Beside similar charging and marginal conditions in case of the same geometric spiroid worm gear drives having arched profile and having linear profile in axial section we have done comparative finite element method analysis for awarding of the strains, deformations and stresses of this gear drives.

  15. Normothermic total arch replacement without hypothermic circulatory arrest to treat aortic distal arch aneurysm in a patient with cold agglutinin disease.

    PubMed

    Ishida, Narihiro; Takemura, Hirofumi; Shimabukuro, Katsuya; Matsuno, Yukihiro

    2011-10-01

    Cold agglutinin disease although rare, can lead to serious complications for patients undergoing cardio-thoracic surgery, especially when cardiopulmonary bypass is applied under hypothermic circulatory arrest. We describe normothermic total arch replacement without hypothermic circulatory arrest in a patient with cold agglutinin disease. The patient tolerated all procedures well and did not develop cerebral ischemia due to surgical maneuvers or thrombotic or haemolytic complications due to cold agglutinin disease. Although endovascular aortic repair is the first choice under such complex conditions, this method could also serve as an alternative strategy when endovascular aortic repair is precluded. PMID:21788303

  16. Non-equilibrium phase transitions

    SciTech Connect

    Mottola, E.; Cooper, F.M.; Bishop, A.R.; Habib, S.; Kluger, Y.; Jensen, N.G.

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Non-equilibrium phase transitions play a central role in a very broad range of scientific areas, ranging from nuclear, particle, and astrophysics to condensed matter physics and the material and biological sciences. The aim of this project was to explore the path to a deeper and more fundamental understanding of the common physical principles underlying the complex real time dynamics of phase transitions. The main emphasis was on the development of general theoretical tools to deal with non-equilibrium processes, and of numerical methods robust enough to capture the time-evolving structures that occur in actual experimental situations. Specific applications to Laboratory multidivisional efforts in relativistic heavy-ion physics (transition to a new phase of nuclear matter consisting of a quark-gluon plasma) and layered high-temperature superconductors (critical currents and flux flow at the National High Magnetic Field Laboratory) were undertaken.

  17. Magnetospheric equilibrium with anisotropic pressure

    SciTech Connect

    Cheng, C.Z. )

    1992-02-01

    Self-consistent magnetospheric equilibria with anisotropic pressure are obtained by employing an iterative metric method for solving the inverse equilibrium equation in an optimal flux coordinate system. A method of determining plasma parallel and perpendicular pressures from either analytic particle distributions or particle distributions measured along a satellite's path is presented. The numerical results of axisymmetric magnetospheric equilibria including the effects of finite beta, pressure anisotropy, and boundary conditions are presented for a bi-Maxwellian particle distribution. For the isotropic pressure cases the finite beta effect produces an outward expansion of the constant magnetic flux surfaces in relation to the dipole field lines, and along the magnetic field the toroidal ring current is maximum at the magnetic equator. The effect of pressure anisotropy is found to further expand the flux surfaces outward. Along the magnetic field lines the westward ring current can be peak away from the equator owing to an eastward current contribution resulting from pressure anisotropy. As pressure anisotropy increases, the peak westward current can become more singular. The outer boundary flux surface has a significant effect on the magnetospheric equilibrium. For the outer flux boundary resembling the dayside compressed flux surface due to solar wind pressure, the deformation of the magnetic field can be quite different from that for the outer flux boundary resembling the taillike flux surface.

  18. Equilibrium Studies of Designed Metalloproteins.

    PubMed

    Gibney, B R

    2016-01-01

    Complete thermodynamic descriptions of the interactions of cofactors with proteins via equilibrium studies are challenging, but are essential to the evaluation of designed metalloproteins. While decades of studies on protein-protein interaction thermodynamics provide a strong underpinning to the successful computational design of novel protein folds and de novo proteins with enzymatic activity, the corresponding paucity of data on metal-protein interaction thermodynamics limits the success of computational metalloprotein design efforts. By evaluating the thermodynamics of metal-protein interactions via equilibrium binding studies, protein unfolding free energy determinations, proton competition equilibria, and electrochemistry, a more robust basis for the computational design of metalloproteins may be provided. Our laboratory has shown that such studies provide detailed insight into the assembly and stability of designed metalloproteins, allow for parsing apart the free energy contributions of metal-ligand interactions from those of porphyrin-protein interactions in hemeproteins, and even reveal their mechanisms of proton-coupled electron transfer. Here, we highlight studies that reveal the complex interplay between the various equilibria that underlie metalloprotein assembly and stability and the utility of making these detailed measurements. PMID:27586343

  19. Are the Concepts of Dynamic Equilibrium and the Thermodynamic Criteria for Spontaneity, Nonspontaneity, and Equilibrium Compatible?

    ERIC Educational Resources Information Center

    Silverberg, Lee J.; Raff, Lionel M.

    2015-01-01

    Thermodynamic spontaneity-equilibrium criteria require that in a single-reaction system, reactions in either the forward or reverse direction at equilibrium be nonspontaneous. Conversely, the concept of dynamic equilibrium holds that forward and reverse reactions both occur at equal rates at equilibrium to the extent allowed by kinetic…

  20. Thermodynamic equilibrium at heterogeneous pressure

    NASA Astrophysics Data System (ADS)

    Vrijmoed, Johannes C.; Podladchikov, Yuri Y.

    2014-05-01

    Recent advances in metamorphic petrology point out the importance of grain-scale pressure variations in high-temperature metamorphic rocks. Pressures derived from chemical zonation using unconventional geobarometry based on equal chemical potentials fit mechanically feasible pressure variations. Here a thermodynamic equilibrium method is presented that predicts chemical zoning as a result of pressure variations by Gibbs energy minimization. Equilibrium thermodynamic prediction of the chemical zoning in the case of pressure heterogeneity is done by constraint Gibbs minimization using linear programming techniques. Compositions of phases considered in the calculation are discretized into 'pseudo-compounds' spanning the entire compositional space. Gibbs energies of these discrete compounds are generated for a given range and resolution of pressures for example derived by barometry or from mechanical model predictions. Gibbs energy minimization is subsequently performed considering all compounds of different composition and pressure. In addition to constraining the system composition a certain proportion of the system is constraint at a specified pressure. Input pressure variations need to be discretized and each discrete pressure defines an additional constraint for the minimization. The proportion of the system at each different pressure is equally distributed over the number of input pressures. For example if two input pressures P1 and P2 are specified, two constraints are added: 50 percent of the system is constraint at P1 while the remaining 50 percent is constraint at P2. The method has been tested for a set of 10 input pressures obtained by Tajčmanová et al. (2014) using their unconventional geobarometry method in a plagioclase rim around kyanite. Each input pressure is added as constraint to the minimization (1/10 percent of the system for each discrete pressure). Constraining the system composition to the average composition of the plagioclase rim

  1. Modeling equilibrium Fe isotope fractionation

    NASA Astrophysics Data System (ADS)

    Anbar, A.; Jarzecki, A.; Spiro, T.

    2003-04-01

    Research into the stable isotope biogeochemistry of Fe and other transition metals has been driven primarily by analytical innovations which have revealed significant isotope effects in nature and the laboratory. Further development of these new isotope systems requires complementary theoretical research to guide analytical efforts. The results of the first such studies show some discrepancies with experiments. For example, Johnson et al. (2002) report an experimentally-determined 56Fe/54Fe equilibrium fractionation factor between Fe(II) and Fe(III) aquo complexes of ˜1.0025. This effect is ˜50% smaller than predicted theoretically by Schauble et al. (2001). It is important to resolve such discrepancies. Equilibrium isotope fractionation factors can be predicted from vibrational spectroscopic data of isotopically-substituted complexes, or from theoretical predictions of some or all of these frequencies obtained using force field models. The pioneering work of Schauble et al. (2001) utilized a modified Urey-Bradley force field (MUBFF) model. This approach is limiting in at least three ways: First, it is not ab initio, requiring as input some measured vibrational frequencies. Such data are not always available, or may have significant uncertainties. Second, the MUBFF does not include potentially important effects of solvent interaction. Third, because it makes certain assumptions about molecular symmetry, the MUBFF-based approach is not able to model the spectra of mixed-ligand complexes. To address these limitations, we are evaluating the use of density functional theory (DFT) as an ab initio method to predict vibrational frequencies of isotopically-substituted complexes and, hence, equilibrium fractionation factors. In a preliminary examination of the frequency shift upon isotope substitution of the bending and asymmetric stretching modes of the tetrahedral FeCl_42- complex, we find substantial differences between MUBFF and DFT predictions. Results for other Fe

  2. Endovascular repair of a type B aortic dissection with a right-sided aortic arch: case report

    PubMed Central

    2013-01-01

    Right-sided aortic arch is a rare anomaly, and aortic dissection involving a right-sided aortic arch is extremely rare. We report the case of a 65-year-old man with a right-sided aortic arch and a right descending aortic dissection and a stent-graft was accurately deployed without perioperative complications. There were no any complaints and complications after 18 months follow-up. The CTA demonstrated that the false lumen was largely thrombosed only with a mild type II endoleak and a mild descending aortic expansion. We feel that endovascular repair is feasible to patient of type B aortic dissection with a right-sided aortic arch. However, long-term clinical efficacy and safety have yet to be confirmed. PMID:23343010

  3. Equilibrium Potentials of Membrane Electrodes

    PubMed Central

    Wang, Jui H.; Copeland, Eva

    1973-01-01

    A simple thermodynamic theory of the equilibrium potentials of membrane electrodes is formulated and applied to the glass electrode for measurement of pH. The new formulation assumes the selective adsorption or binding of specific ions on the surface of the membrane which may or may not be permeable to the ion, and includes the conventional derivation based on reversible ion transport across membranes as a special case. To test the theory, a platinum wire was coated with a mixture of stearic acid and methyl-tri-n-octyl-ammonium stearate. When this coated electrode was immersed in aqueous phosphate solution, its potential was found to be a linear function of pH from pH 2 to 12 with a slope equal to the theoretical value of 59.0 mV per pH unit at 24°. PMID:4516194

  4. Neoclassical equilibrium in gyrokinetic simulations

    SciTech Connect

    Garbet, X.; Dif-Pradalier, G.; Nguyen, C.; Sarazin, Y.; Grandgirard, V.; Ghendrih, Ph.

    2009-06-15

    This paper presents a set of model collision operators, which reproduce the neoclassical equilibrium and comply with the constraints of a full-f global gyrokinetic code. The assessment of these operators is based on an entropy variational principle, which allows one to perform a fast calculation of the neoclassical diffusivity and poloidal velocity. It is shown that the force balance equation is recovered at lowest order in the expansion parameter, the normalized gyroradius, hence allowing one to calculate correctly the radial electric field. Also, the conventional neoclassical transport and the poloidal velocity are reproduced in the plateau and banana regimes. The advantages and drawbacks of the various model operators are discussed in view of the requirements for neoclassical and turbulent transport.

  5. String fluid in local equilibrium

    NASA Astrophysics Data System (ADS)

    Schubring, Daniel; Vanchurin, Vitaly

    2014-10-01

    We study the solutions of string fluid equations under the assumption of a local equilibrium which was previously obtained in the context of the kinetic theory. We show that the fluid can be foliated into noninteracting submanifolds whose equations of motion are exactly that of the wiggly strings considered previously by Vilenkin and Carter. In a special case of negligible statistical variance in either the left- or the right-moving directions of microscopic strings, the submanifolds are described by the action of a null-current-carrying chiral string. When both variances vanish the submanifolds are described by the Nambu-Goto action and the string fluid reduces to the string dust introduced by Stachel.

  6. Local non-equilibrium thermodynamics

    PubMed Central

    Jinwoo, Lee; Tanaka, Hajime

    2015-01-01

    Local Shannon entropy lies at the heart of modern thermodynamics, with much discussion of trajectory-dependent entropy production. When taken at both boundaries of a process in phase space, it reproduces the second law of thermodynamics over a finite time interval for small scale systems. However, given that entropy is an ensemble property, it has never been clear how one can assign such a quantity locally. Given such a fundamental omission in our knowledge, we construct a new ensemble composed of trajectories reaching an individual microstate, and show that locally defined entropy, information, and free energy are properties of the ensemble, or trajectory-independent true thermodynamic potentials. We find that the Boltzmann-Gibbs distribution and Landauer's principle can be generalized naturally as properties of the ensemble, and that trajectory-free state functions of the ensemble govern the exact mechanism of non-equilibrium relaxation. PMID:25592077

  7. Equilibrium calculations of firework mixtures

    SciTech Connect

    Hobbs, M.L.; Tanaka, Katsumi; Iida, Mitsuaki; Matsunaga, Takehiro

    1994-12-31

    Thermochemical equilibrium calculations have been used to calculate detonation conditions for typical firework components including three report charges, two display charges, and black powder which is used as a fuse or launch charge. Calculations were performed with a modified version of the TIGER code which allows calculations with 900 gaseous and 600 condensed product species at high pressure. The detonation calculations presented in this paper are thought to be the first report on the theoretical study of firework detonation. Measured velocities for two report charges are available and compare favorably to predicted detonation velocities. However, the measured velocities may not be true detonation velocities. Fast deflagration rather than an ideal detonation occurs when reactants contain significant amounts of slow reacting constituents such as aluminum or titanium. Despite such uncertainties in reacting pyrotechnics, the detonation calculations do show the complex nature of condensed phase formation at elevated pressures and give an upper bound for measured velocities.

  8. Local non-equilibrium thermodynamics.

    PubMed

    Jinwoo, Lee; Tanaka, Hajime

    2015-01-01

    Local Shannon entropy lies at the heart of modern thermodynamics, with much discussion of trajectory-dependent entropy production. When taken at both boundaries of a process in phase space, it reproduces the second law of thermodynamics over a finite time interval for small scale systems. However, given that entropy is an ensemble property, it has never been clear how one can assign such a quantity locally. Given such a fundamental omission in our knowledge, we construct a new ensemble composed of trajectories reaching an individual microstate, and show that locally defined entropy, information, and free energy are properties of the ensemble, or trajectory-independent true thermodynamic potentials. We find that the Boltzmann-Gibbs distribution and Landauer's principle can be generalized naturally as properties of the ensemble, and that trajectory-free state functions of the ensemble govern the exact mechanism of non-equilibrium relaxation. PMID:25592077

  9. Hierarchical condensation near phase equilibrium

    NASA Astrophysics Data System (ADS)

    Olemskoi, A. I.; Yushchenko, O. V.; Borisyuk, V. N.; Zhilenko, T. I.; Kosminska, Yu. O.; Perekrestov, V. I.

    2012-06-01

    A novel mechanism of new phase formation is studied both experimentally and theoretically in the example of quasi-equilibrium stationary condensation in an ion-plasma sputterer. Copper condensates are obtained to demonstrate that a specific network structure is formed as a result of self-assembly in the course of deposition. The fractal pattern related is inherent in the phenomena of diffusion limited aggregation. Condensate nuclei are shown to form statistical ensemble of hierarchically subordinated objects distributed in ultrametric space. The Langevin equation and the Fokker-Planck equation related are found to describe stationary distribution of thermodynamic potential variations at condensation. Time dependence of the formation probability of branching structures is found to clarify the experimental situation.

  10. Non-linear heterogeneous FE approach for FRP strengthened masonry arches

    NASA Astrophysics Data System (ADS)

    Bertolesi, Elisa; Milani, Gabriele; Fedele, Roberto

    2015-12-01

    A fast and reliable non-linear heterogeneous FE approach specifically conceived for the analysis of FRP-reinforced masonry arches is presented. The approach proposed relies into the reduction of mortar joints to interfaces exhibiting a non-linear holonomic behavior, with a discretization of bricks by means of four-noded elastic elements. The FRP reinforcement is modeled by means of truss elements with elastic-brittle behavior, where the peak tensile strength is estimated by means of a consolidated approach provided by the Italian guidelines CNR-DT200 on masonry strengthening with fiber materials, where the delamination of the strip from the support is taken into account. The model is validated against some recent experimental results relying into circular masonry arches reinforced at both the intrados and the extrados. Some sensitivity analyses are conducted varying the peak tensile strength of the trusses representing the FRP reinforcement.

  11. Sonic hedgehog is required for the assembly and remodeling of branchial arch blood vessels.

    PubMed

    Kolesová, Hana; Roelink, Henk; Grim, Milos

    2008-07-01

    Sonic hedgehog (Shh) is a morphogen involved in many developmental processes. Injection of cells (5E1) that produce a Shh-blocking antibody causes an attenuation of the Shh response, and this causes vascular malformations and impaired remodeling characterized by hemorrhages and protrusions of the anterior cardinal vein and outflow tract, delayed fusion of the dorsal aortae, impaired branching of the internal carotid artery, and delayed remodeling of the aortic arches. Distribution of smooth muscle cells in the vessel wall is unchanged. In 5E1-injected embryos, we also observed impaired assembly of endothelial cells into vascular tubes, particularly in the sixth branchial arch, around the anterior cardinal vein and around the dorsal aorta. In 5E1-treated embryos, increased numbers of macrophage-like cells, apoptotic cells, and a decreased level of proliferation were observed in head mesenchyme. Together, these observations show that Shh signaling is required at multiple stages for proper vessel formation and remodeling. PMID:18570256

  12. Clinical and Laboratory Steps for Fabricating a Complete-Arch Fixed Prosthesis Using CAD/CAM.

    PubMed

    Keerthi, Senthil; Proussaefs, Periklis; Lozada, Jaime

    2015-01-01

    The fabrication of a full-arch maxillary prosthesis has been associated with several prosthetic complications and difficulties. Even though it has been reported that phonetics, esthetics, and proper lip support are difficult to achieve, there is a scarcity in the literature regarding the clinical and laboratory procedures necessary to minimize these complications. This article provides clinical and laboratory steps that may enable the clinician to achieve more predictable restorative results when using computer-aided design/computer-assisted manufacture (CAD/CAM) to fabricate a full-arch maxillary implant-supported prosthesis. The technique presented here describes the use of an implant-retained diagnostic wax-up that is subsequently duplicated to an interim polymethylmethacrylate prosthesis using CAD/CAM before fabricating the definitive restoration. PMID:26133136

  13. Distribution, morphology, and origin of ridges and arches in Mare Serenitatis

    NASA Technical Reports Server (NTRS)

    Maxwell, T. A.; Ward, S. H.; El-Baz, F.

    1975-01-01

    Lunar mare ridges and arches in Mare Serenitatis were mapped to understand better their mode of formation. Maps of these features indicate that several pre-mare impacts in the Serenitatis area may be responsible for the localization of the circular ridge systems and that the subsurface, pre-mare topography is more complex than previously recognized. Apollo Lunar Sounder cross sections of ridge systems in southern Serenitatis indicate 50 to 100 m of local relief on these features. Small-scale features of ridges, such as medial lineations and lobate margins, do not conclusively define the origin of the ridges. However, estimates of crustal shortening from Lunar Sounder data and the coincidence of the major ridge system with the Serenitatis mascon suggest that ridges and arches were formed by gravitational readjustments of the mare fill along four probable impact structures and along a north-trending fracture pattern.

  14. Modelling and numerical simulation of the human aortic arch under in vivo conditions.

    PubMed

    García-Herrera, Claudio M; Celentano, Diego J

    2013-11-01

    This work presents the modelling and simulation of the mechanical behaviour of the human aortic arch under in vivo conditions with pressure levels within the normal and hypertension physiological range. The cases studied correspond to young and aged arteries without cardiovascular pathologies. First, the tissue of these two groups is characterised via in vitro tensile test measurements that make it possible to derive the material parameters of a hyperelastic isotropic constitutive model. Then, these material parameters are used in the simulation of young and aged aortic arches subjected to in vivo normal and hypertension conditions. Overall, the numerical results were found not only to provide a realistic description of the mechanical behaviour of the vessel but also to be useful data that allow the adequate definition of stress/stretch-based criteria to predict its failure. PMID:23371524

  15. Elasto-Viscoplastic Block Element Method and its Application to Arch Dam Abutment Slopes

    NASA Astrophysics Data System (ADS)

    Chen, S.-H.; Shahrour, I.; Egger, P.; Wang, W.-M.

    2002-08-01

    This paper presents an elasto-viscoplastic block element method and its application to the deformation and stability study of arch dam abutment slopes. The paper is composed of two parts. The first part concerns the numerical methods used in the analysis, which includes the identification of the rock blocky system, the algorithm of unconfined seepage flow in discontinuity network taking the grout curtain and drainage curtain into account, and the elasto-viscoplastic block element method as well. In the second part a complicated arch dam abutment slope is studied, from which the seepage flow, the deformation, and the safety factor of the abutment slope are obtained. Based on the analysis suggestions about the seepage control and stabilization measures are made.

  16. Dinosaur tracks from the Cedar Mountain Formation (Lower Cretaceous), Arches National Park, Utah

    USGS Publications Warehouse

    Lockley, M.G.; White, D.; Kirkland, J.; Santucci, V.

    2004-01-01

    The seventh and largest known dinosaur tracksite from the Cedar Mountain Formation is reported from two important stratigraphic levels in the Ruby Ranch Member within the boundaries of Arches National Park. Previous reports of sites with a few isolated tracks are of limited utility in indicating the fauna represented by track makers. The Arches site reveals evidence of several theropod morphotypes, including a possible match for the coelurosaur Nedcolbertia and an apparently didactyl Utahraptor-like dromeosaurid. Sauropod tracks indicate a wide-gauge morphotype (cf. Brontopodus). Ornithischian tracks suggest the presence of an iguandontid-like ornithopod and a large ankylosaur. Dinosaur track diversity is high in comparison with other early Cretaceous vertebrate ichnofaunas, and it correlates well with faunal lists derived from skeletal remains, thus providing a convincing census of the known fauna. ?? Taylor and Francis Inc.

  17. Hand1 phosphoregulation within the distal arch neural crest is essential for craniofacial morphogenesis.

    PubMed

    Firulli, Beth A; Fuchs, Robyn K; Vincentz, Joshua W; Clouthier, David E; Firulli, Anthony B

    2014-08-01

    In this study we examine the consequences of altering Hand1 phosphoregulation in the developing neural crest cells (NCCs) of mice. Whereas Hand1 deletion in NCCs reveals a nonessential role for Hand1 in craniofacial development and embryonic survival, altering Hand1 phosphoregulation, and consequently Hand1 dimerization affinities, in NCCs results in severe mid-facial clefting and neonatal death. Hand1 phosphorylation mutants exhibit a non-cell-autonomous increase in pharyngeal arch cell death accompanied by alterations in Fgf8 and Shh pathway expression. Together, our data indicate that the extreme distal pharyngeal arch expression domain of Hand1 defines a novel bHLH-dependent activity, and that disruption of established Hand1 dimer phosphoregulation within this domain disrupts normal craniofacial patterning. PMID:25053435

  18. [A case of a syndrome resembling PSP after aortic arch replacement under deep hypothermic circulatory arrest].

    PubMed

    Sakiyama, Yusuke; Michizono, Kumiko; Tomari, Shinya; Watanabe, Osamu; Nakahara, Keiichi; Takashima, Hiroshi

    2011-01-01

    A 57-year-old man presented with acute signs and symptoms mimicking PSP (bradykinesia, supranuclear ocular palsy, dysphagia, neck dystonia, and apraxic gait) on the day after a graft replacement surgery, which was performed for aortic arch aneurysm under deep hypothermic circulatory arrest (rectal temperature, 18 degrees C). Dysphagia improved temporarily, but relapsed after a few months. Symptoms did not change during 2 years of antiparkinsonian drug administration. Brain images obtained before the surgery revealed slight atrophy of the midbrain tegmentum and frontal lobes, but the patient was asymptomatic. No findings of cerebral vascular disease and hypoxic encephalopathy were observed on brain images after the surgery. These clinical features resembling PSP might have been caused by deep hypothermia and the patient's predisposition for PSP. This is the first case report in Japan of a syndrome resembling PSP that occurred after aortic arch replacement under deep hypothermic circulatory arrest. PMID:21387699

  19. Mycotic aortic arch aneurysm coexistent with constrictive pericarditis: is surgery a dangerous resort?

    PubMed

    Yu, Peter S Y; Yu, Simon C H; Chu, Cheuk-Man; Kwok, Micky W T; Lam, Yuk-Hoi; Underwood, Malcolm J; Wong, Randolph H L

    2016-08-01

    An elderly man presented with fever and evidence of Salmonella infection, and was diagnosed to have coexisting constrictive pericarditis and mycotic aneurysm of the aortic arch. Pericardiectomy was performed under cardiopulmonary bypass with good result. To avoid deep hypothermic circulatory arrest, an aorto-brachiocephalic bypass, instead of total arch replacement, was performed. This was followed by a staged carotid-carotid bypass, thoracic endovascular stent graft placement. He was subsequently treated with prolonged antibiotics, and inflammatory marker normalized afterwards. He was last seen well 2 years after the operation. Follow-up computer tomography (CT) scan at 18 months post-op showed no evidence of endoleak or fistulation. Our case demonstrated that a hybrid treatment of open pericardiectomy and aortic debranching followed by thoracic endovascular stent graft placement is feasible and associated with satisfactory mid-term outcome. PMID:27621905

  20. Mycotic aortic arch aneurysm coexistent with constrictive pericarditis: is surgery a dangerous resort?

    PubMed Central

    Yu, Peter S. Y.; Yu, Simon C. H.; Chu, Cheuk-Man; Kwok, Micky W. T.; Lam, Yuk-Hoi; Underwood, Malcolm J.

    2016-01-01

    An elderly man presented with fever and evidence of Salmonella infection, and was diagnosed to have coexisting constrictive pericarditis and mycotic aneurysm of the aortic arch. Pericardiectomy was performed under cardiopulmonary bypass with good result. To avoid deep hypothermic circulatory arrest, an aorto-brachiocephalic bypass, instead of total arch replacement, was performed. This was followed by a staged carotid-carotid bypass, thoracic endovascular stent graft placement. He was subsequently treated with prolonged antibiotics, and inflammatory marker normalized afterwards. He was last seen well 2 years after the operation. Follow-up computer tomography (CT) scan at 18 months post-op showed no evidence of endoleak or fistulation. Our case demonstrated that a hybrid treatment of open pericardiectomy and aortic debranching followed by thoracic endovascular stent graft placement is feasible and associated with satisfactory mid-term outcome. PMID:27621905