Sample records for arch bridges

  1. Precast Pearl-Chain concrete arch bridges

    Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup


    the technology was used. We also study other important components and details in the Pearl-Chain Bridge concept and review the effects of different types of loads. A theoretical case study of a circular 30 m span Pearl-Chain Bridge is presented showing the influence of a number of parameters: The......A Pearl-Chain Bridge is a closed-spandrel arch bridge consisting of a number of straight pre-fabricated so called Super-Light Deck elements put together in an arch shape by post-tensioning cables. Several Pearl-Chain arches can be positioned adjacent to each other by a crane to achieve a bridge of...... number of post-tensioning cables, the rise to span ratio, the height of the filling, and the height of the Super-Light Decks. We find that Pearl-Chain Bridges can be adjusted to resist specific moment loads by changing the normal force in the arch cross section by altering the above parameters. It is...

  2. Structural behavior and design criteria for bridge strengthening by tied arch. Comparison with network arch bridges

    Valenzuela, Matías A.; Casas Rius, Joan Ramon


    This study focuses on a new strengthening method of continuous bridges with several spans that present extensive damage in their foundation/piers due to scour and erosion. The method consists on the construction of a new upper steel arch with a network hanger's arrangement over the original deck with the aim to hang the existing deck to the new arch. The deck is acting as a tie in the new structural configuration. This allows to remove the damaged foundations/piers, deriving on an arch bridge...

  3. Excitation of Arch and Suspension Bridges by Subwires

    Noriaki Hiwatashi


    Full Text Available A force generation method using a subwire for arch and suspension bridges is proposed. The subwire is connected to the arch or the cable of the bridge through rollers. The uniform force produced by pulling and releasing the pretensioned subwires acts on the bridge as an externalforce. A new device called “the resonance force generator” is also developed to excite the bridges by applying a small force. To verify the proposed concept, a stress ribbon bridge was excited with the resonance force generator.

  4. Excitation of Arch and Suspension Bridges by Subwires

    Noriaki Hiwatashi; Yoji Mizuta; Yutaka Ishihara; Itio Hirai


    A force generation method using a subwire for arch and suspension bridges is proposed. The subwire is connected to the arch or the cable of the bridge through rollers. The uniform force produced by pulling and releasing the pretensioned subwires acts on the bridge as an externalforce. A new device called “the resonance force generator” is also developed to excite the bridges by applying a small force. To verify the proposed concept, a stress ribbon bridge was excited with the resonance force ...

  5. Track-Bridge Longitudinal Interaction of Continuous Welded Rails on Arch Bridge

    Rong Chen


    Full Text Available Taking arch bridges, including deck, half-through, and through arch bridges (short for DAB, HTAB, and TAB as examples, mechanics analysis models of longitudinal interaction between continuously welded rails (short for CWRs and arch bridges are established. Based on the finite element method (FEM, the longitudinal interaction calculation software of CWR on arch bridges has been developed. Focusing on an HTAB, the tension, compression, and deflection conditions are calculated and analyzed. The results show that the mechanics analysis models of three types of arch bridges can truly reflect the real state of the structure; the calculation software can be used for systematic research of the CWR on arch bridge; as for HTAB, temperature difference of arch rib has a small effect on rail tension/compression, and arch bridge can be simplified as a continuous beam for rail tension/compression additional force calculation; in calculation of deflection conditions of HTAB, it is suggested that train loads are arranged on half span and full span and take the direction of load entering bridge into account. Additionally, the deflection additional force variation of CFST basket handle arch bridge is different from that of ordinary bridge.

  6. Seismic vulnerability of historical arch type bridge structures in Italy

    Qadir Bhatti, Abdul


    Italy is located on a earthquake prone area and old bridges were desinged without any seismic provision. In the years (2009), tremors were felt in Italy due to the strong earthquakes at Abruzzo, which highlight the earthquake threat to Italy. This study focuses on seismic vulnerability of arch type masonry bridge structures in Italy, designed primarily for gravity loads, when they are subjected to earthquakes. A case study has been carried out for the vulnerability study for a ...

  7. The seismic response of concrete arch bridges (with focus on the Bixby Creek bridge Carmel, California)

    Hoehler, M; McCallen, D; Noble, C


    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.

  8. Dynamic response of arch bridges traversed by high-speed trains

    Lacarbonara, Walter; Colone, Valerio


    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. Approach for analyzing the ultimate strength of concrete filled steel tubular arch bridges with stiffening girder

    ZHANG Zhi-cheng; XIE Xu; ZHANG He; CHEN Heng-zhi


    A convenient approach is proposed for analyzing the ultimate load carrying capacity of concrete filled steel tubular (CFST) arch bridge with stiffening girders. A fiber model beam element is specially used to simulate the stiffening girder and CFST arch rib. The geometric nonlinearity, material nonlinearity, influence of the construction process and the contribution of prestressing reinforcement are all taken into consideration. The accuracy of this method is validated by comparing its results with experimental results. Finally, the ultimate strength of an abnormal CFST arch bridge with stiffening girders isinvestigated and the effect of construction method is discussed. It is concluded that the construction process has little effect on the ultimate strength of the bridge.

  10. Design of a single-track railway network arch bridge : According to the Eurocodes

    Varennes, Maxime


    A constant research of more ecological and efficient structures has enabled bridges to be more innovative through the years. Nowadays, as the need is greater than ever, a new kind of bridge is expanding in the entire world: the network arch bridges. The concept was developed by professor and engineer Per Tveit in 1955 and has been improved since then. But it is only for 10 years that many bridges of this sort have been built. The aim of the thesis is to investigate the structural behavior of ...

  11. An Automatic Method for Geometric Segmentation of Masonry Arch Bridges for Structural Engineering Purposes

    Riveiro, B.; DeJong, M.; Conde, B.


    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.

  12. Fatigue Performance Assessment of Composite Arch Bridge Suspenders Based on Actual Vehicle Loads

    Bin Chen


    Full Text Available In the through arch bridges, the suspenders are the key components connecting the arch rib and the bridge deck in the middle, and their safety is an increasing focus in the field of bridge engineering. In this study, various vehicle traffic flow parameters are investigated based on the actual vehicle data acquired from the long-term structural health monitoring system of a composite arch bridge. The representative vehicle types and the probability density functions of several parameters are determined, including the gross vehicle weight, axle weight, time headway, and speed. A finite element model of the bridge structure is constructed to determine the influence line of the cable force for various suspenders. A simulated vehicle flow, generated using the Monte Carlo method, is applied on the influence lines of the target suspender to determine the stress process, and then the stress amplitude spectrum is obtained based on the statistical analysis of the stress process using the rainflow counting method. The fatigue performance levels of various suspenders are analyzed according to the Palmgren-Miner linear cumulative damage theory, which helps to manage the safety of the suspenders.

  13. Design and stability analysis of continuous skew tied-arch bridge over Bin Jiang River

    Jiancheng YU; Hao TONG; Wei HUANG


    A tied arch bridge without wind bracing was built over the Bin Jiang River, with oblique angle of 20°. Its main design details are described and mechanical performances are analyzed. The stability analytical types are also introduced and the first elastic stability theory is used. A space finite element model has been built to analyze the stability performances in both construction and operation stages for single span or continuous, orthogonal or oblique bridge. The influence of stiffness of the end crossbeam is also analyzed. The result shows that out-plane buckling occur for a rigid tie and similar no matter whether it is single span or continuous and orthogonal or oblique. When there are more and stronger inner crossbeams, the influence of the end crossbeams on arch stability becomes unremarkable.

  14. Arch-bridge Lift Process Monitoring by Using Packaged Optical Fibre Strain Sensors with Temperature Compensation

    This paper presents a novel sensor design and packaging, specifically developed to allow fibre grating-based sensors to be used in harsh, in-the-field measurement conditions for accurate strain measurement, with full temperature compensation. After these sensors are carefully packaged and calibrated in the laboratory, they are installed onto the paragrid of a set of flat-packed concrete units, created specifically for forming a small-scale, lightweight and inexpensive flexi-arch bridge. During the arch-bridge lifting process, the sensors are used for real-time strain measurements to ensure the quality of the construction. During the work done, the sensors have demonstrated enhanced resilience when embedded in concrete structures, providing accurate and consistent strain measurements during the whole installation process and beyond into monitoring the integrity and use of the structure.

  15. Attenuating resonant behavior of a tied arch railway bridge using increased hanger damping

    Andersson, Andreas; Karoumi, Raid


    In this paper, dynamic analyses and field measurements of a tied arch railway bridge is presented. Excessive vibrations of the hangers were obtained, caused by resonance during train passages. The resulting increase of the stress level and number of stress cycles were shown to decrease the fatigue service life significantly. The most critical section is a threaded turnbuckle connection of the hangers. Due to low damping of the hangers, more than 50 % of the cumulative fatigue damage was relat...

  16. Finding the lost arches of the Medieval Avignon's Bridge (Avignon, Provence, South France): a geoarchaeological approach

    Ghilardi, M.; Vella, M. A.; Hermitte, D.; Parisot, J. C.; Dussouillez, P.; Fleury, T. J.; Provansal, M.; Delanghe-Sabatier, D.; Demory, F.; Mathé, P. E.; Quesnel, Y.; Danos, S.; Balossino, S.; Delpey, Y.; Hartmann-Virnich, A.; Berthelot, M.


    This papers aims to precisely locate the medieval arches of the so called Avignon's (Saint Bénézet) Bridge (South France) and to reconstruct the fluvial dynamics of the Rhone River from Early Medieval Times to the 19th century. Until now, just four remnant arches are still visible (near Avignon) and it is estimated that 22 arches (which represents a total length of approximately 920 meters) were built to span over one of the largest French Rivers. The late roman and early mediaeval dates of several foundation poles extracted from the river bed might suggest the existence of an earlier bridge, though it remains uncertain if any of such an earlier structure was still visible when the first mediaeval bridge was built. The mediaeval bridge was erected from 1177 until 1185 (in less than 10 years), but modified a few decades later when stone arches were erected, thus raising the road level substantially. The structure of the bridge being vulnerable, seasonal floods proved a neverending threat and cause of damage which was frequently repaired with masonry or wood. Final abandon of the edifice could be placed in the late 1660s - Early 1670s according to historical sources. Questions arose about the location of the "lost arches" and evident flood events dated back to the Little Ice Age (e.g. 1500 to 1850) could be responsible of the partial destruction of the bridge. Few archaeological, architectural, historical and palaeoenvironmental works have been undertaken in order to determine the precise shape of the Saint Bénézet Bridge at certain stages of its history. Since 2010, a joint team composed by laboratories affiliated to the French Public Research Centre (CNRS) and to Universities of Avignon and of Aix-Marseille 1 is trying to link the different phases of constructions/destructions of the monument with the fluvial dynamics of the Rhone River for the concerned period (ANR PAVAGE). The geoarchaeological approach adopted comprises bathymetric surveys (SONAR and

  17. Testing of the masonry arches of the Brooklyn Bridge approaches

    Limaye, Hemant S.


    Diagnostic procedures play an important role in performing a condition survey of a structure. Specialized tests are used during a field survey to supplement visual observations. The tests provide valuable information regarding the internal condition of the structure and quality of the construction materials. The tests also help in determining the extent of damage, if any. Recently, a team of consulting engineers performed a study to determine the remaining capacity of the Brooklyn Bridge approaches for the Department of Transportation, City of New York. Using advanced diagnostic procedures such as impact-echo and flatjack testing, additional information was gathered to assist in the study. Impact-echo testing was helpful in identifying the condition of the brick soffits which were covered with pneumatically- applied concrete, and flatjack testing was useful in determining in-situ compressive strength and compression modulus of the brick masonry. The paper describes the work and the testing results.


    Tomislav Novosel


    Full Text Available On the site of Maslenica bridge structural tectonic, geophysical and engineering geological investigations, geotechnical drilling and laboratory sample testings were performed. Maslenica anticline is characteristic for the investigated area. It is built from the limestone of Cretaceous age. The anticline has an asymmetrical form with the vergence of the axial plane towards the north. Reverse faults with recent activities are present. The recent activity was proved by the discovery of the broken stalactite with the displacement of 11 cm, whose age is 36000 years. On quite young stalactites (stalagmites in the cave on the west side, no displacements were noticed. For the next period of 500 years the maximal possible displacement of 2.0 cm is foreseen. Smaller caves with the dimensions of 1 m3, were formed on the intersections of the reverse faults and greater joints. The canyon Novsko ždrilo was formed in the fault shear zone with tectonic transport to the right. According to the range of fracture, three characteristic types of rock masses were separated by engineering geological investigations. According to »Geomechanical classification« (RMR the first type corresponds to II to III class, while the second type corresponds to IV class, and the third type corresponds to V class (mylonite. Because of the complexity of the terrain structure, original engineering geological bases of design have not enabled the direct application of the analysis of stress-strain behaviour. Because of that the simplified geotechnical models were done. They enabled the projecting of foundation in the rock mass and renewal of poor quality rock mass.

  19. Reinforcement and numerical analysis on the corbel of a half-through arch bridge

    LIAO Bi-hai; WANG Yuan-han; CHENG Hong-guang; MIAO Yu


    Corbels support the crossbeams of half-through arch bridges. They are prone to cracking easily due to their characteristics and complicated loading conditions. Based on a practical diagnosis of a bridge crossbeam, we bonded steel plates onto bridge corbels to strengthen them. We carried out a numerical analysis on the effectiveness of the reinforcement by using the commercial software ANSYS. The numerical analysis shows that the stresses near the section break increased slightly, but the variation amplitude was small and all the stresses were within an allowable range. The loading test indicates that it is feasible to strengthen the corbel with vertical bonded steel plates. Therefore, the reinforcement is effective and economical. This reinforcement method is suitable for this type of corbel and can be applied in similar cases.

  20. Traveling wave effect on the seismic response of a steel arch bridge subjected to near fault ground motions

    Xu Yan; George C Lee


    In the 1990s, several major earthquakes occurred throughout the world, with a common observation that near fault ground motion (NFGM) characteristics had a distinct impact on causing damage to civil engineering structures that could not be predicted by using far field ground motions. Since then, seismic responses of structures under NFGMs have been extensively examined, with most of the studies focusing on structures with relatively short fundamental periods, where the traveling wave effect does not need to be considered. However, for long span bridges, especially arch bridges, the traveling wave (only time delay considered) effect may be very distinct and is therefore important. In this paper, the results from a case study on the seismic response of a steel arch bridge under selected NFGMs is presented by considering the traveling wave effect with variable apparent velocities. The effects of fling step and long period pulses of NFGMs on the seismic responses of the arch bridge are also discussed.

  1. Dynamic and Fatigue Analysis of an 18th Century Steel Arch Bridge

    Within the 'Oran-Tlemcen' railway line realization project (159 km), several bridges were built by the Railroads Algerian West Company. 7 km from the east of Tlemcen city, this railway line must cross a very broken mountainous collar, that's why the French engineer 'Gustave Eiffel' was solicited to construct a 68 m length bridge. In 1890, an arch steel truss bridge was realized. The bridge presents 300 m of apron curvature radius and, currently, is considered as one of the most important monuments of the Algerian historical heritage. Considering the age of the bridge and the evolution of the railway loads in time, it was essential to check the good behavior of the studied structure. For that, analyses to verify the physical and mechanical properties of the growth iron members are made. A finite element model of the bridge was built and numerical simulations were drawn. The structural vibration conducted analysis permit to understand the behavior of this particular structure, then to evaluate (in detail) the rate of the structure fatigue

  2. 斜靠式系杆拱桥拱肋安装技术%The Installation Technology of Arch Ribs of Leaning Type CFST Arch Bridge



    通过南通新开北路通启运河大桥施工实例,介绍了斜靠式系杆拱桥的拱肋安装施工技术,并对影响拱肋安装精度的因素进行了分析,对如何控制做了简述。%This article introduces the installation and construction technology of arch ribs of leaning-type CFST arch bridge with the construction example of Nantong Tongqi canal bridge on North Xinkai road. And it also analyzes the factors of the accuracy of rib installation and makes a brief introduction of how to control.

  3. The behaviour of a historic masonry arch bridge regarding dynamic loads

    Yesid Mauricio Ospina


    Full Text Available This article describes the analysis of a historic brick arch bridge constructed in Colombia during the 18th century for predicting its behavior in response to loads produced by seismic activity and determining its vulnerability. Two studies were carried out prior to the seismic analysis to obtain basic information regarding the structure's overall behavior (modal analysis and linear static analy- sis, both stemming from a three-dimensional model constructed by the finite elements method. Seismic excitation was simulated in the conditions proposed by 1998 Colombian seismic-resistant norms (NSR-98. The results obtained agreed with the bridge’s history and with its response to earthquakes; the comparison between seismic loads and the resistance capacity of the materials constituting the structure confirms the vulnerability of these types of constructions regarding localised damage and the possibility of collapse. The results suggest that this procedure can be applied to other historic structures in Colombia.

  4. Applications of Non-destructive methods (GPR and 3D Laser Scanner) in Historic Masonry Arch Bridge Assessment

    Alani, Amir; Banks, Kevin


    There exist approximately 70,000 masonry arch bridge spans (brick and stone) in the UK with tens of thousands more throughout Europe. A significant number of these bridges are still in operation and form part of the road and rail network systems in many countries. A great majority of these bridges are in desperate need of repair and maintenance. Applications of non-destructive testing methods such as ground penetrating radar (GPR), 3D laser scanning, accelerometer sensors and vibration detecting sensors amongst many others have been used to assess and monitor such structures in the past few years. This presentation provides results of the applications of a 2GHz GPR antenna system and a 3D laser scanner on a historic masonry arch bridge (the Old Bridge, Aylesford) located in Kent, in the south east of England. The older part of the bridge (the mid-span) is 860 years old. The bridge was the subject of a major alteration in 1811. This presentation forms part of a larger ongoing study which is using the two above mentioned non-destructive methods for long-term monitoring of the bridge. The adopted survey planning strategy and technique, data acquisition and processing as well as challenges encountered during actual survey and fieldworks have been discussed in this presentation. As a result of this study the position of different layers of the deck structure has been established with the identification of the original stone base of the bridge. This information in addition to the location of a number of structural ties (anchors - remedial work carried out previously) in the absence of reliable and accurate design details proved to be extremely useful for the modelling of the bridge using the finite element method. Results of the 3D laser scanning of the bridge have also been presented which have provided invaluable data essential for the accurate modelling of the bridge as well as the long term monitoring of the bridge. 2014 EGU-GA GI3.1 Session, organised by COST Action

  5. Optimal Design of Concrete Tied Arch Bridge%混凝土系杆拱桥优化设计

    乔建东; 吴慧山; 杨伟


    为探讨混凝土系杆拱桥的多参数优化设计方法,选取计算矢高、拱肋截面尺寸、系梁截面尺寸、吊杆面积和系梁纵向预应力筋数目作为设计变量,规范限值为约束条件,全桥总造价为目标函数,建立了混凝土系杆拱桥的优化模型;采用大型通用程序ANSYS和桥梁结构平面分析程序,结合混合整型序列二次规划法,混合编程求解优化模型.以某拱桥为工程背景,建立并求解优化模型,将优化结果与设计值进行比较.结果表明:系梁混凝土用量减少40.98%,拱肋混凝土用量减少23.81%,预应力钢筋数目减少28.23%,全桥材料总造价降低28.63%.%In order to investigate the multi-parameter optimal design method of concrete tied arch bridges,an optimal model was established. In this model,rise,cross section dimensions of arch ribs and tied beams,area of each suspender and number of pre-stressed steel bars in each hole are selected as the design variables,code values as the constraint conditions,and total cost of whole bridge as the objective function. A plane analysis program for bridge structure,the software ANSYS and the mix-integer sequence quadratic program method were used together to program and solve the optimal model. The optimal model was solved by taking an arch bridge as engineering background,the optimal results were compared with the design values. The comparison results show that the concrete consumptions of tied beams and arch ribs is respectively reduced by 40 . 98% and 23 . 81%,the number of pre-stressed steel bars is decreased by 28 . 23%,and the total material cost is cut by 28 . 63%.

  6. 结合梁桥面系异形钢箱拱肋系杆拱桥设计%Design of Special-shaped Steel Box Arch Rib Bowstring Arched Bridge of Bonding Beam Deck System



    The main bridge of Putian Chenggang Avenue Bridge crossing Molan River is the special-shaped bowstring arched bridge of 2-span simple-supported double-rib half-through steel box arch rib bonding beam deck system. The single span is 72 m long and the bridge is 47.5 m wide with city-Class A load and double-direction of 8 lanes. Taking the preliminary design and construction drawing design of this bridge as the basis, the article introduces the scheme study of bridge type, structural design of main bridge and analysis of structural calculation of the special-shaped bowstring arched bridge, and analyzes some technical characteristics of this bridge. The design method of the main bridge inclined crossed with the curve river, the design thinks of bonding beam in the arched bridge, the temporary constructed supporting point for improving the structural bearing, and the design method of special arch rib modeling can be referred for the design of the similar bridges.%莆田城港大道跨木兰溪大桥主桥是两跨简支的双肋下承式钢箱拱肋结合梁桥面系的异形系杆拱桥,单跨跨径72m,桥宽47.5m,城一A级荷载,双向8车道.该文以该桥的初步设计和施工图设计为基础,介绍了异形系杆拱桥的桥型方案研究、主桥结构设计、结构计算分析等内容,并分析了该桥的一些技术特点.该桥的弯曲河道斜交主桥设计方法、结合梁在拱桥中的设计思想、结合梁横梁设置临时支点改善结构受力、独特拱肋造型的设计方法等内容,可供类似桥梁设计时参考.

  7. The Reinforcement and Reconstruction Design of a Hollow Type Arch Bridge%某空腹式拱桥加固改造设计



    拱桥最为我国最常用的一种桥梁形式,其使用时间较长时容易出现病害。本文以一山区空腹式拱桥为例,对其病害情况、加固措施及施工要点等进行了分析与研究,希望能为相关工程提供借鉴。%Arch bridge is the most commonly used bridge form in China, which can easily cause diseases when use for a long time. This article takes a hol ow type arch bridge in a mountain as an example and carries on the analysis and study of the disease situation, the reinforcement measures, and the main points of construction, and hope to provide reference for related projects.

  8. Research on Multi-Parameter of Butterfly Arched Bridge Stability%蝴蝶拱桥稳定性多参数影响研究



    以某蝴蝶拱桥为工程背景,建立该桥的空间有限元计算模型,分4个工况计算了该桥的稳定安全系数。通过改变拱肋外倾角度、拱肋刚度、端横梁刚度以及吊杆布置形式计算了不同设计参数下结构在恒栽工况以及恒载+活载工况的失稳特征值。结果表明,拱肋的刚度对稳定性起着决定性作用;吊杆的布置形式只改变拱肋的面内刚度,对于面外刚度没有影响。%Taking some butterfly arched bridge as the engineering background, the study establishes tile spatial finite ele- ment computation model of the bridge, and the stability safety index is calculated in four kinds of construction conditions. Through the change of arch rib camber angle, rigidity of the arch rib, the end beam rigidity as well as the arrangement of suspension bar, imbalance eigen values of the structure are calculated in the dead load operating mode as well as the dead load + live load operating mode. The result indicates that, the arch rib rigidity plays a decisive role in the stability; The suspension bar arrangement only changes the arch rib in plane rigidity and has nothing to do without plane rigidity.

  9. 中承单肋式钢拱桥静力性能分析%Half-through single-rib steel arch bridge static performance analysis



    Taking Xiamen Tianyuan Bridge as the project background , based on static-state load test , the paper collects strain data and deflection data , analyzes static performance of bridge , provides technical support for conservation and management of half -through single-rib steel arch bridge.%本文以厦门市天圆大桥为工程背景,通过静力荷载试验,测试桥梁主要控制截面的应变、挠度数据,分析桥梁的静力性能,为今后中承单肋式钢拱桥的养护管理提供技术依据。

  10. 浅论拱桥的技术进步与挑战%On Technical Advancement and Challenge of Arch Bridges

    李亚东; 姚昌荣; 梁艳


    The basic characteristics of span length development of some arch bridges (including the steel, reinforced concrete and concrete-filled steel tube arch bridges) having been built in the world in the rcccnt one century are surveyed and with reference to the thc basic characteristics of the techniques having been applied to construction of the different types of the bridges, the construction methods for the bridges arc summrized into three major kinds, that is, the scaffolding method, cantilever method and large component shifting method. On the basis of the techniques for the construction of the bridges, several technical issues on the structures and durability of the arch bridges in China in their development process are studied. To clarify the relationship between the structures and architectural style of the bridges and the relationship between the mechanics and aesthetics, the determination of a bridge type scheme is divided into two aspects of the bridge type selection and bridge configuration and the related basic principles are put forward, that is, for the bridge type selection, the principle is that of the "clear force conditions and simple structure" , for the bridge configuration, the principle is the "simple configuration and integral coordination" , for the construction investment, the principle is the "easy construction and rational cost" while for thc features of the bridge itself, the principle is the "harmony with environment and distinguished features" and further all these principles mentioned herewith are elaborated and analyzed by way of case study of practical bridges.%通过分析百年来拱桥(包括钢拱桥、钢筋混凝土拱桥、钢管混凝土拱桥)跨度发展的基本特点,并根据各种拱桥施工技术的基本特征,把拱桥施工方法分为3大类,即支架法、悬臂法和大件转移法.基于拱桥施工技术,探讨了中国拱桥发展历程中的构造、耐久性等技术问题.为厘清桥梁结构与建筑的关

  11. Live-Load Testing and Finite-Element Analysis of a Steel Cantilever Deck Arched Pratt Truss Bridge for the Long-Term Bridge Performance Program

    Laurendeau, Matthew P.


    The Long Term Bridge Performance (LTBP) program is an organization within the Federal Highway Administration that inspects, tests, analyzes, and observes, for an extended period of time, a variety of bridge types throughout the United States. Part of the program includes periodic testing of select bridges of a span of 20 years. The Kettle River Bridge located outside of Sandstone, Minnesota was selected for study due to its unique design. The Kettle River Bridge is a historical steel can...

  12. 下套拱加固石拱桥复合拱圈极限承载力研究%Research on ultimate load -carrying capacity of composite arch ring ofstone arch bridge reinforced by concrete arch -lifted method

    孙潮; 刘明; 陈宝春; 吴庆雄


    The composite arch ring formed by soffitting method for stone arch consists four materials, i.e. , stone, mortar, concrete and steel bars. It is a secondary loaded structure, so its behavior is complicated. A finite element method (FEM) to calculate the ultimate load -carrying capacity of the composite arch ring is proposed by using both smeared model and discrete model. The computing results from FEM agrees well with the test results, which indicates that the behavior of the composite arch ring can be depicted well by the proposed FEM. Analysis of a real engineering have been done by using this FEM. Analysis results shows that under the half span distributed load and quarter point load, the failure mode of the composite arch ring is a four - hinges mechanism. The load reaches 77.9% of the ultimate load when the second hinge appears. Ultimate load - carrying capacity decreases with the increase of the ratio of concentrated live load to the total live load, also increases with the increase of the thickness of reinforcement layer and reinforcement ratio. The concrete strength has a little influence on the ultimate load - carrying capacity of composite arch ring, so high strength concrete is not necessary to be adopted in this method.%下套拱加固石拱桥形成的复合拱圈由石块、砂浆、混凝土和钢筋四种材料组成,而且属于二次受力结构,受力复杂.采用分离模型和整体连续体模型相结合的方法,提出复合拱圈的极限承载力有限元计算方法.有限元计算结果与试验结果吻合良好,表明有限元计算方法能够反映复合拱圈的受力性能.应用该方法,对某实桥进行了分析,结果表明,复合拱圈在半跨均布活载和L/4集中活载联合作用下的破坏模式为四铰破坏,第二个铰出现时荷载已达极限荷载的77.9%.复合拱圈的极限承载力随着集中活载占总活载的比例的增大而减小,随加固层厚度和配筋率的增大而增大.

  13. 钢管混凝土系杆拱桥施工监控%The Construction Monitoring of Tied Concrete-filled Steel Tubular Arch Bridges

    宋维侠; 晋智斌; 沈建华


    在钢管混凝土系杆拱桥整个施工过程中施工现场布置了应力和变形监测点,实时监测桥梁结构的实际状态,运用现代控制理论对误差进行识别,调整预测,使桥梁施工状态最大限度地接近理想状态,保证桥梁结构在施工过程中的安全。钢管混凝土系杆拱桥施工监控就施工控制的各阶段较好地控制了施工中的结构应变行为,保证了大桥的顺利施工,为钢管混凝土系杆拱桥的安全施工提供了可靠依据。%Bymeansofsettingupstressanddeformationmonitoringpointsintheconstructionsitefortheconstructionprocessofconcrete-filled steeltubulararchbridgeandmonitoringtheactualstateofthebridgestructureinrealtime,coupledwiththeerrorsidentification,adjustment and prediction based on modern control theory. It is feasible to achieve rational complete bridge state and to ensure the safety of constructing bridge. In order to provide the theory basis for the smooth and safe construction of the concrete-filled steel tubular arch bridge, it has been dis-cussed on how to scientifically monitor the stress and deformation in different construction procedures.

  14. Influence of Void on Stress of Concrete Filled Steel Tubular Arch Bridge%脱空对钢管混凝土拱桥受力的影响分析



    Effect of void on the stress characteristics of concrete filled steel tubular arch bridge relates pa-rameters of arch bridge, such as void ratio, steel ratio, truss higher parameters, and so on.Using finite ele-ment analysis method, the article analyzes the state of concrete filled steel tubular arch bridge in void con-dition, and get result about the effect of void on different parameters of concrete filled steel tubular arch bridge, such as stiffness, stability and dynamic characteristics. It will provide reference on theory for relat-ed design in future.%脱空对钢管混凝土拱桥受力特性的影响与拱桥的脱空率、含钢率、桁高等参数有关。采用有限元分析方法对脱空状态下的钢管混凝土拱桥状态进行了具体分析,得到脱空对不同拱桥参数如刚度、稳定性及动力特性等的影响结果,为今后钢管混凝土拱桥的设计提供一定的理论参考。

  15. 上承式拱梁组合桥设计%Design of combined deck type arch bridge



    结合某桥的工程地理位置及沿河景观要求,对该桥的结构设计特点、构造与施工要点等进行了简要介绍,目前该桥运营情况良好,并取得了一定的经济、社会效益,为同类型桥梁施工积累宝贵经验。%This paper synthesized the engineering geographic location and river landscape requirements of a bridge,simply introduced the structure design features,structure and construction key points of this bridge,present the bridge was operating in good condition,and achieved certain economic,social effect,accumulated valuable experience for the same type bridge construction.

  16. 某异型系杆拱桥空间力学特性分析%Analysis of Spatial Mechanical Properties of an Irregular-Shape Tied Arch Bridge



    为研究斜吊杆异型系杆拱桥的空间力学特性,以某异型系杆拱桥为研究对象,采用MIDAS Civil建立该桥空间有限元模型,分析其在施工和使用阶段的静、动力特性及结构稳定性.分析结果表明:该桥斜吊杆附加应力对拱肋影响较大,全桥纵、横梁框架体系整体刚度较大,拱肋挠度对整体降温比较敏感,使用阶段各吊杆应力幅比较均匀,为50 MPa左右;拱肋侧倾刚度较小,拱肋刚度对全桥刚度贡献较大,各阶段稳定系数均较高;吊杆调索对全桥应力水平有较大影响,施工中应予注意.%To study the spatial mechanical properties of irregular-shape tied arch bridges with inclined hangers, a tied arch bridge of the same type was taken as the research object, the MIDAS Civil was used to set up the spatial finite element model for the bridge, the static, dynamic prop-erties and structural stability of the bridge at construction and service stages were analyzed. The results of the analysis indicate that the impact of additional stress of the inclined hangers on the arch ribs is great. The global rigidity of the stringer and cross beam frame system of the whole bridge is considerable. The deflection of the arch ribs is sensitive to temperature fall. The stress amplitude of the hangers at service stage is uniform and is about 50 Mpa. The lateral inclination rigidity of the arch ribs is little, the contribution of the rigidity of the arch ribs to the rigidity of the whole bridge is great and the stability factors of various stages are high. The adjustment of the hanger cables has considerable impact on the stress levels of the whole bridge, to which atten-tion should be paid in the process of construction.

  17. 钢管混凝土拱桥桥面铺装动力学特性研究%Research on Dynamics Characteristics of Deck Pavement of Concrete-Filled Steel Tube Arch Bridge

    杨咏梅; 庄月明


    首先,建立了千岛湖钢管混凝土拱桥的3D有限元模型.通过有限元计算,得到了该钢管混凝土拱桥前8阶的自振频率和自振振型.同时,计算了该钢管混凝土拱桥的水平自振基频与竖向自振基频.接着,选用移动恒载研究车辆荷载作用下的钢管混凝土拱桥桥面铺装结构动力学特性.计算得到该钢管混凝土拱桥的共振速度并分析了桥梁共振响应的可能性.计算了不同车速下跨中节点的竖向最大位移与纵向拉应力,并进一步计算了冲击系数,提出了钢管混凝土拱桥的荷载冲击系数参考值.最后,考虑施工荷载,计算了梁底最大拉应力与最大剪应力,分析了Dynapac CC522型振动压路机施工时对桥梁结构的影响.%First of all, finite element 3D model of the concrete-filled steel tube arch bridge above Qian-dao Lake is established. By calculation of finite element method, the initial eight stages auto-oscillation frequency and mode of the concrete-filled steel tube arch bridge are acquired. Meanwhile, horizontal and vertical auto-oscillation fundamental frequency of the concrete-filled steel tube arch bridge is calculated. Secondly, moving constant load is used to research the dynamics characteristics of deck pavement of the concrete-filled steel tube arch bridge. Resonance velocity of the concrete-filled steel tube arch bridge above Qiandao Lake is computed to analyze the probability of bridge resonance. The maximum vertical displacement and longitudinal tensile stress of mid-span node under different vehicle speeds are calculated. Furthermore, impact coefficient reference value of the concrete-filled steel tube arch bridge is put forward. Finally, considering construction loads, the maximum tensile stress and shearing stress of beam bottom are calculated to analyze the influence of construction exploiting "Dynapac CC522" vibratory roller.

  18. Comparison of Erection Schemes for Steel Tube Arch of Main Bridge of Huanghe River Bridge on Zhungeer-Shuozhou Railway%准朔铁路黄河特大桥主桥钢管拱架设方案比选



    准朔铁路黄河特大桥主桥为主跨380 m的上承式钢管混凝土拱桥,主拱肋为钢管混凝土主弦杆和箱形钢腹杆组成的空间桁架结构。针对该桥结构特点和施工难点,提出了支架拼装并竖转合龙方案、单拱肋单元吊装与双拱肋单元整体吊装的“缆扣法”施工方案,通过技术可行性、经济性、安全性等方面的比选,采用单拱肋和双拱肋单元整体吊装相结合的“缆扣法”施工方案。重量超过缆索吊设计吊重的节段采用单拱肋分别吊装两侧的单肢拱肋,安装K撑和横撑,在空中形成设计节段;其余节段在拼装场形成设计节段,整体运输到缆索吊下方,整体吊装后与前一节段在空中对接,然后扣索,依次形成半拱,最后完成合龙,并灌注钢管混凝土。%The main bridge of the Huanghe River Bridge on Zhungeer‐Shuozhou Railway is a concrete‐filled steel tube (CFST) deck arch bridge with a main span of 380 m .The main arch ribs of the bridge are the spatial truss structure that is composed of the CFST main chords and box steel web members .In the light of the structural features and construction difficulties of the bridge ,the scheme of assembling the main arch ribs on scaffoldings and closing the arch ribs by vertically rotating and the construction scheme of fastening stay method for lifting the single arch rib element and integrally lifting the double arch ribs element were proposed .Through compari‐son of the technical feasibility and the construction cost and safety ,it was determined that the construction scheme of fastening stay method for both lifting the single arch rib element and inte‐grally lifting the double arch ribs element should be adopted .For the arch rib element that was heavier than the designed lifting capacity of the cable crane ,the single arch rib element was lifted only ,the single‐leg rib at each side of the element was respectively lifted and the K

  19. Study of Key Construction Control Technique of Steel Pipe Concrete Arched Bridge%钢管混凝土拱桥施工控制关键技术研究

    王亚超; 张晋


    该文结合湖州市奚家庄大桥主拱施工监控方案,运用有限元分析程序和现代测量手段相结合,对钢管混凝土拱桥施工控制中的关键技术进行了深入的研究,可供同类工程施工参考.%Combined with the main arch construction monitoring scheme of Huzhou City Xijiazhuang Bridge, the article uses the finite element analysis program and the modern measuring means to deeply study the key technique in the construction control of steel pipe concrete arched bridge, which can be referred for the similar projects.

  20. 钢管混凝土拱桥吊杆张拉方案比选%Comparison and Selection of Tensioning Scheme for Hangers of Concrete-Filled Steel Tube Arch Bridge



    The main bridge of the Shahe River Bridge on Xingtai‐Fenyang Expressway is a con‐crete‐filled steel tube through arch bridge with a main span of 146 m .The hangers of the bridge were to be constructed by the unstressed state method .To determine the tensioning sequences and to ensure the safety of the tensioning process of the hangers in the construction ,4 types of the hanger tensioning schemes were proposed ,i .e .① the hangers were to be symmetrically tensioned from the arch springs at both ends of the bridge towards the arch crown ;② the hangers to be sym‐metrically tensioned from the arch crown towards the arch springs ;③ the hangers to be symmetri‐cally tensioned from the 1/4 or 3/4 arch ribs towards the arch springs and midspan and ④ the hangers to be tensioned in 3 batches .The software MIDAS Civil was used to set up the finite ele‐ment model for the whole bridge of the bridge ,the simulation calculation was conducted and the tensile forces of the hangers ,displacement of the arch ribs ,core concrete stress of the arch ribs and horizontal thrust of the arch springs of the completed bridge of the 4 tensioning schemes were analyzed .The results of the analysis show that for the scheme 4 ,the tensile forces of the hangers of the completed bridge are closest to the designed tensile forces ,the geometric shapes of the arch ribs are good ,the changing of the concrete compressive stress in the arch rib cross section is uni‐form .No great compressive stress occurs and the influence of the stress on the horizontal thrust of the arch springs is little .In the actual construction ,the scheme 4 is therefore selected .In the scheme ,the hangers of the bridge need not to be adjusted for the second time ,the construction progress of the bridge can be accelerated and the construction cost is also saved .%邢汾高速公路沙河特大桥主桥为主跨146 m的下承式钢管混凝土拱桥,吊杆采用无应力状态法施工。为确定该桥吊

  1. The Rotary Construction Technology of Beipanjiang Steel Tube Arch Bridge on Shuibai Railway in Guizhou%贵州水柏铁路北盘江大桥钢管拱转体施工技术

    陶建山; 任旭初; 陈国祥


    Beipanjiang Bridge is the first single track deck arch bridge made of steel-tubes, with a spanlength of 236 m. In this paper, the method of factory-manufacture of the elements of steel-tube arch ribs, the welding tecnology in the job-site erection, the rotary structure of the steel-tube arch bridge, the control of the alignement as well as the method of closure with single-hinged rotary technology of the 10 thousand dwt halfarches are introduced.%北盘江大桥是第一座单线铁路上承式钢管拱桥,跨度为236 m。介绍钢管拱工厂单元制造、工地拼装焊接,钢管拱桥的转体结构、线形控制,以及半拱万吨单铰转体合龙的施工技术。

  2. Design and Construction of Concrete Mixture Ratio for Steel Tube Arch Bridge%钢管拱桥混凝土配合比设计与施工



    西藏昌都澜沧江大桥为大跨度、薄壁钢管混凝土拱桥,其钢管混凝土施工采用泵送顶升法,施工难度大,对混凝土性能要求高。经混凝土配合比设计与优化,制备出满足设计要求的C50微膨胀钢管混凝土,并进行混凝土的拌合物性能、物理力学性能及微观结构分析研究,结果表明,所配制的混凝土不离析、不泌水,坍落度23 cm,混凝土拌和物3 h后的坍落度不小于18 cm,混凝土具有早强、高弹性模量和补偿收缩等性能,完全满足西藏昌都澜沧江大桥钢管混凝土拱桥的工程设计及施工要求。%The Qamdo Lancang river bridge of Tibet is big span, thin-walled concrete-filled steel tube arch bridge. The concrete filled steel tube uses pumping jack-up construction method, which is difficult in construction and has high performance requirements of concrete. Through concrete mixture ratio design and optimization, C50 micro expansive concrete filled steel tube is prepared to meet the design requirements, and the mixture performance physical and mechanical properties and microstructure analysis of concrete are studied. The results show that the mixed concrete has no segregation and no bleeding, 23 cm slump. The slump of concrete mixing content after 3 h is no less than 18 cm. Concrete has high early strength, elastic modulus and shrinkage compensation, fully meeting the engineering design and construction requirements of the bridge.

  3. Techniques for the Construction of the Arch Ribs of the 113.3 m Bow-String Arch Bridge of the Da-Xi Passenger-Oriented Railway%大西客专113.3m系杆拱桥拱肋施工技术

    赵方刚; 李君君


    对大西客专l临汾特大桥113.3m系杆拱桥的主拱肋施工技术进行了介绍,主要包括钢管混凝土主拱肋的制造、安装以及泵送钢管混凝土材料的技术性能指标、施工配合比和顶升施工注意事项等,可为同类桥梁施工提供有益的参考。%Introduced in detail in the paper are the construction techniques for the main arch ribs of the 113.3 m Linfen mega tie arch bridge of the Da-Xi Passengers-oriented Railway, including the manufacturing and installation of the arch ribs, technical targets for pump-conveying concrete materials for steel tubes, construction mixture ratios and points for attention for jacking-up construction techniques, etc. The paper may serve as a useful reference for the construction of other similar bridges.

  4. Line type control for construction of a basket-style tied bars arch bridge%某提篮式系杆拱桥施工过程的线形控制



    以广州市南沙区凤凰三桥为工程背景,针对该桥拱肋拼装后整体吊装,主梁悬臂拼装的特殊施工过程,精确计算其钢箱拱及钢箱梁的三大线形(成桥线形、安装线形、预拼线形),结合具体的施工方法,揭示了三大线形之间的内部转化关系以及各种线形与施工方法的关联性。%This article took the third Fenghuang bridge located in Nansha district Guangzhou as engineering background. After the bridge arch rib assembly for lifting the overall and the main beam cantilever erection of special construction process,calculate accurately line type( line type of sus-pension bridge,alignment line type,preassembly line type)of the steel box arch and steel box girder. Contacting the specific construction methods, reveal internal transformation of the relationship between the three line type and the correlation of a variety of line type and construction methods.

  5. Equivalent Imperfections In Arched Structures

    Dallemule Marian


    Full Text Available 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.

  6. Construction Monitoring and Control of a Long Span CFST Basket Handle Tied Arch Bridge on High-Speed Railway%高速铁路大跨钢管混凝土提篮式拱桥施工监控

    王君; 杨振伟; 王高彦


    To ensure that the geometric shape, stress and internal force of long span concrete-filled steel tube (CFST) basket handle tied arch bridge on high-speed railway can meet their requirements, the 128-m span CFST through basket handle tied arch bridge of Nielson system on Beijing-Shanghai High-Speed Railway spanning Shanghai-Nanjing Expressway was cited as an example. In accordance with the finite element analysis theory, the large scale software MIDAS Civil was used to set up the spatial model and to conduct the corresponding theoretic analysis, and the geometric shapes, stress and internal forces of the tie beams, arch ribs and hangers of the bridge were monitored and controlled. The results reveal that the settlement amount of the tie beams at the early construction stage is little. The settlement amount of the arch ribs at the construction stage after removal of temporary supports of the arch ribs is close to the theoretic valuesand the influence of the settlement amount on the global geometric shape of the bridge is not great. The changing tendencies of the stress measured from each cross section of the tie beams and arch ribs are coincident with the theoretic values and the tie beams and arch ribs are in the range of safety. The relative differences between the measured and target cable forces of the hangers are within +5% and the cable forces can meet the design requirements.%为确保高速铁路大跨度混凝土提篮式拱桥的线形、应力及内力满足要求,以京沪高铁跨沪宁高速公路128m下承式尼尔森体系钢管混凝土提篮式系杆拱桥为例,根据有限元分析理论,采用大型空间有限元分析软件MIDAS Civil建立空间模型进行理论分析,对系梁、拱肋、吊杆进行线形、应力及索力监控.结果显示,系梁在前期施工期间沉降量较小,拆除拱肋临时支架以后的施工阶段中拱肋沉降量与理论计算值较接近,对整体线形影响不大;系梁和拱肋各应力测试截面

  7. Assembly and lifting of Pearl-Chain arches

    Halding, Philip Skov; Hertz, Kristian Dahl; Viebæk, N.E.;


    buildings and bridges. The assembly and lifting of two Pearl-Chain arches, with a span of 13 m and rise of 1 m, is considered in this paper. Precast “Super-Light Deck” elements were used for the arches, which had a thickness of 22 cm. Both arches were successfully lifted, rotated in mid-air, and placed...

  8. Analysis of Mechanical Behavior and Stability of CFST Tied Arch Bridge in Construction Process%钢管混凝土系杆拱桥施工中受力性能及稳定性分析

    陈钒; 王建欣; 王江宇; 韩大勇


    To provide the theoretic bases for the construction monitoring and control of concrete-filled steel tube (CFST) tied arch bridge, the Yaowan Water Channel Highway Bridge in Nanyang City of the South-to-North Water Diversion Project was cited as an example, the finite element software was used to set up the three-dimensional model for the whole bridge of the bridge, the internal forces and deformation history of the bridge in the whole construction process and the force conditions of the scaffoldings for concreting of the tie beams were analyzed in detailed consideration of the various factors of the concreting sequences, concrete creep effect, hanger tensioning sequences and multi-time tensioning of the hangers. The results of the analysis show that the stress of the arch rib steel tubes and the concrete in the tubes in the construction process can meet the relevant requirements in the codes. The compressive stress of the concrete in the different branch steel tubes is related to the concreting sequences. The creep of the concrete in the tubes can cause the stress redistribution in the sections of the CFST and the scaffoldings for concreting of the arch ribs can meet the requirements of global and local stability.%为给钢管混凝土系杆拱桥施工监控提供理论依据,以南水北调工程南阳市姚湾跨渠公路桥为背景,采用有限元软件建立全桥三维空间模型,详细考虑混凝土灌注次序、混凝土徐变效应、吊杆张拉次序、系梁多次张拉等环节,对结构施工全过程的内力和变形历程及系梁浇筑过程中支架受力进行分析.结果表明,施工过程中拱肋钢管及管内混凝土应力满足规范要求;各分支钢管中混凝土的压应力与混凝土灌注次序有关;钢管内灌注混凝土的徐变会使钢管混凝土截面发生应力重分布;拱肋支架满足整体稳定性和分支稳定性要求.

  9. Mechanical Behaviors of Key Joints of Concrete-Filled Steel Tube Tied Arch Bridge%钢管混凝土系杆拱桥关键节点的受力行为



    为研究钢管混凝土系杆拱桥关键节点的受力行为,以某钢管混凝土系杆拱桥为工程背景,采用有限元方法对其全过程非线性受力行为进行深入分析.首先,建立钢管混凝土拱桥整体模型,对其整体受力行为进行分析,提取系杆拱桥关键节点在设计荷载工况下的最不利内力情况;然后以力边界条件形式施加给节点三维精细有限元模型,对拱脚节点和拱肋吊装节点在设计荷载工况下进行应力分析,探讨2种节点在设计荷载工况下的受力行为;最后,考虑材料非线性行为,采用弧长法对2类节点极限承载力进行分析,探讨其承载非线性行为及安全储备.研究结果表明:这2种节点构造形式在设计荷载工况下均安全可靠,且具有较大的安全储备;拱脚节点区拱肋钢管与系梁上翼缘板相交处存在明显的应力集中现象,该处构造复杂,焊缝多,设计时应重点关注;吊装节点区下弦钢管径向刚度小,采用环向加劲肋加强后,对钢管刚度及承载力均有显著改善.%In order to study the mechanical behaviors of key joints of concrete-filled steel tube (CFST) tied arch bridge, the whole process of nonlinear mechanical behaviors of the key joints was analyzed by finite element method. First, the FEM model of the CFST arch bridge was established to analysis the global mechanical behaviors, and the most unfavorable internal forces of key joints of the tied arch bridge under design loads were extracted. Second, the extracted internal forces were applied to the spatial fine finite element model of joints, and the mechanical behaviors of arch foot joint and arch rib hoisting joint under design loads were analysed to discuss the mechanical behaviors of both kinds of joints under design loads. Finally , considered the nonlinear performance of material, the ultimate bearing capacities of two kinds of joint were calculated by using arc-length method to discuss the

  10. Structure and distribution of arches in shaken hard sphere deposits

    Pugnaloni, Luis A.; Barker, G. C.


    We investigate the structure and distribution of arches formed by spherical, hard particles shaken in an external field after they come to rest. Arches (or bridges) are formed during a computer-simulated, non-sequential deposition of the spheres after each shaking cycle. We identify these arches by means of a connectivity criterion and study their structural characteristics and spatial distribution. We find that neither the size distribution nor the shape of the arches is strongly affected by...

  11. 大跨度系杆拱桥减隔震支座参数分析%Parameter Analysis of Long-span Tied-arch Bridge Seismic Isolation Bearing

    刘聪; 李建中


    结合一座大跨系杆拱桥实例,分析了不同减隔震支座参数对系杆拱桥减震性能的影响.通过对比发现,支座的球心距越大,减震效果越好.支座的摩擦系数越大,减震效果表现为先减小后变大的趋势,摩擦系数取0.02~0.03时,支座位移和墩台剪力达到最好的减震效果.但是支座参数的不同对承台底剪力总体的影响很小.%This paper takes a large span tied-arch bridge as an example, analyzes the damping performance of the tied-arch bridge with different minus isolation bearing. Through the contrast we find that the bigger of the distance of the two sphericalsurface' s center, the better of the damping effect. While the friction coefficient of the sliding spherical surface gets bigger, the damping effect displays the trend to get first smaller and then bigger. With the friction coefficient at 0.02 ~0.03, there is an optimal effect on the bearing displacement and the sheer force of the bottom section of the pier and the pile caps. But the overall effect is very small for the sheer force of the pile caps.

  12. Thomas Young's theory of the arch: Thermal effects

    Huerta Fernández, Santiago


    The engineers of the 18th century were well aware of the movements suffered by arch bridges due to changes of temperature. In 1801 this problem caused concern to the experts reporting on Telford’s design for a 600 feet iron arch. Vicat reported in 1824 “un mouvement périodique” in the arches of the bridge of Souillac and George Rennie published in 1842 the movements observed in Southwark Bridge after its completion in 1818. However the analysis of these perturbations was studied much later, w...

  13. 系杆拱桥吊杆节点足尺模型承载性能试验研究%Full-Scale Model Test Study of Load-Carrying Behavior of Hanger Joint of Tied Arch Bridge

    桂水荣; 陈水生; 万水


    To study if the strength of the anchor head in anchorage zone of the hanger joint of tied arch bridge could meet the load-carrying requirements, the Shengmi Bridge in Nanchang was cited as an example, the full-scale model for the anchorage zone of the hanger joint at arch crown of the bridge was fabricated and the load-carrying capacity of the joint under the action of the de signed load was tested. The spatial finite element model of the anchorage zone was established and the theoretic values of the finite element and the measurement values of the test were comparatively analyzed. The results of the analysis show that the global strength of the double-layer steel socket of the hanger joint can meet the requirements, however, the local compressive strength values of the contact between the stiffening plates and the steel padding plate exceed the allowable values and the stiffening plates should be reinforced. The fabrication accuracy of the model has influence on the proportions of the load shared by the inner layer and outer layer of the steel socket and in the future tests of the similar kind, attention should be paid.%为研究系杆拱桥吊杆节点锚固区锚头强度是否满足受力要求,以南昌生米大桥为研究背景,制作拱顶吊杆节点锚固区的足尺模型,测试在设计荷载作用下吊杆节点承载力,并建立空间有限元模型,对比分析有限元理论值与试验实测值.研究结果表明:双层钢套筒整体强度满足要求,但加劲板与钢垫板接触位置局部抗压强度超过允许值,应对加劲板予以补强.模型试件的制作精度影响内钢管与外钢套筒分担荷载比例,在今后的类似试验过程中应予以重视.

  14. 波司登长江大桥拱肋高性能混凝土设计与试验%Design and test of high-performance arch rib concrete of Bosideng Yangtze River Bridge

    王建军; 李冉; 谢开仲


    为得到主跨530 m的中承式钢管混凝土桁架拱桥———波司登长江大桥的拱肋管内C60高性能混凝土混凝土基准配合比,采用密实骨架堆积法进行设计,得到初步配合比为水泥:粉煤灰:砂:石子:水=430:140:701:1041:156。以初步配合比为基础进行制备和试验,优化了胶凝材料体系,硅灰掺量确定为30 kg/m3,经过对混凝土的工作性能和力学性能进行试验检验,最终确定满足大桥使用性能要求的基准配合比为水泥:粉煤灰:硅灰:砂:石:水=430:110:30:701:1041:156。%To determine the reference mixing proportion of the high-performance C60 concrete used in the arch rib of Bosideng Yangtze River Bridge which is a half-through concrete filled steel tube ( CFST) truss arch bridge with a main span of 530 m, the dense frame accumulation method was a-dopted in design, and a preliminary mixing proportion of cement :fly ash( FA) :sand :gravel :water=430:140:701:1041:156 was obtained. Based on the proportion, the concrete was prepared, a test was conducted and the cementitious material system was optimized. The mixing amount of silica fume was determined to be 30 kg/m3 . After the test verification about the working performance and mechanical properties, a reference mixing proportion of the concrete for the bridge was determined as cement :FA :Silica fume(SF) :sand :gravel :water=430:110:30:701:1041:156.

  15. Interaction between long -span continuous arch bridge and continuously welded rail%大跨度铁路连续梁-拱组合桥与无缝线路相互作用研究

    戴公连; 刘瑶


    To study the interaction between continuous arch bridge and CWR (Continuously Welded Rail), nonlinear bar elements were used to simulate the track -bridge contact.Taking the (82.9 +172 +82.9)m prestressed concrete continuous arch bridge with concrete -filled steel tube as an example,a model was estab-lished by considering arch,derrick,girder,track and neighboring structures.The distributions of the longitudinal forces of CWR and the horizontal forces at the top of piers were systematically analyzed under the actions of ben-ding,braking,thermal effect,wind,shrinkage and creep as well as settlement of bearing.The following conclu-sions are obtained:The temperature load in beam has the greater influence on the track that lies in the middle of the beam than at the end of the beam.Under the action of live load and the braking force,the impact that the load position on the middle of structure is bigger.When strong wind reaches at the speed of 1 kN /m,it is neces-sary to consider the effect of wind load.Creep and shrinkage of concrete with drop in temperature have adverse effects on the rail.Under uneven settlement,the maximum stress in track is 4.9 MPa.When designing the rail track,the above factors should be considered.%研究大跨度铁路连续梁-拱组合桥与无缝线路的相互作用问题,采用非线性弹簧单元模拟梁轨接触,以某桥(82.9+172+82.9)m 连续梁拱桥为例,建立考虑拱肋、横撑、斜撑、吊杆、主梁、轨道以及相邻路基梁轨相互作用模型,系统分析温度荷载、活载、制动力、风荷载、混凝土收缩徐变、支座不均匀沉降作用下连续梁-拱桥无缝线路纵向力的分布规律。研究结果表明:钢轨在跨中位置对梁体升温敏感程度大于梁端位置;单线活载与制动或牵引作用下,钢轨应力在中间加载时比左、右侧加载大;纵向风力达到1 kN /m 以上的地区,须考虑风荷载的影响;同时,混凝土收缩

  16. 单跨双曲拱桥的检测与分析%Testing and Analysis of Single-span Double-curve Arched Bridge

    冷冰峰; 马文滢


    According to a single-span double-curve bridge constructed in the early stage, the article sets forth in detail how to carry out the safety testing, and puts forward the suitable handling suggestion on the practical background of the project.%该文针对某早期建造的单跨双曲拱桥如何进行安全性检测进行了具体阐述,并根据工程实际背景条件提出了适当的处理建议.

  17. Research on reasonable side and mid-span ratio of railway long-span continuous beam-arch bridge%大跨度铁路连续梁拱组合桥的合理边中跨比研究

    戴公连; 唐立新; 汪禹


    为了解边中跨比对大跨度铁路连续梁拱组合桥受力特性的影响,对目前大跨度铁路梁拱组合桥的边中跨比进行统计,并以兰渝线某(82+172+82)m 连续梁拱组合桥为工程背景,分析边中跨比对该桥内力、变形、支反力、稳定性等方面影响。研究结果表明:大跨度铁路连续梁拱组合桥的合理边中跨比取值为0.46~0.51;边中跨比取值较小时,对结构受力和变形有利,但边支座负反力的出现限制其值应大于0.43;边中跨比的取值对该桥基频和结构稳定性影响较小,随边中跨比由0.447增加到0.506,该桥的稳定安全系数仅增大7.6%。%Span ratio is one of the important design parameters in continuous beam -arch bridge,which directly affects the structural stress reasonably.In order to learn the effects of span ratio on the structural force of railway continuous beam -arch bridge,statistics of span ratio in the current long -span railway beam -arch bridges was analyzed.Taking an (82 +172 +82)m long -span continuous beam -arch bridge on the Lanzhou -Chongqing railway as an example,the effects of span ratio on its internal force,displacement,support reaction,stability and so on were analyzed.The analysis results show that the span ratio of long -span railway continuous beam -arch bridge varies from 0.46 to 0.51.Small span ratio is in favor of structural stress and deformation,but the e-mergence of negative support reaction limits its value should be greater than 0.43.While the contribution of span ratio to natural frequency and structural stability is small.Moreover,it is found that the value of stability factors only increased 7.6% with the span ratio increasing from 0.447 to 0.506.

  18. Investigating the Hysteretic Behavior of Concrete-Filled Steel Tube Arch by Using a Fiber Beam Element

    Jun Ma


    Full Text Available A fiber beam finite element that could account for the nonlinear constitutive relationship between steel and concrete was applied to investigate the hysteretic behavior of concrete filled steel tube (CFT arch ribs of bridges. At first, the effectiveness of this fiber beam element using for nonlinear analysis was verified by comparing the analytical results with the experimental data, and then this composite element was applied to analyze the hysteretic performance of CFT arch ribs. The following hysteretic behavior of CFT arch ribs of bridges was investigated such as the hysteretic behaviors of moment-curvature of arch ribs in vertical direction of bridge and the hysteretic relationship between load and displacement of arch ribs in longitudinal and transverse direction of bridge. Finally, some parameters affecting the hysteretic behaviors of CFT arch ribs were presented by evaluating the capacity of ductility of CFT arch ribs.

  19. Dental arch asymmetry

    Al-Zubair, Nabil Muhsen


    Objective: This study was conducted to assess the dental arch asymmetry in a Yemeni sample aged (18-25) years. Materials and Methods: The investigation involved clinical examination of 1479 adults; only 253 (129 females, 124 males) out of the total sample were selected to fulfill the criteria for the study sample. Study models were constructed and evaluated to measure mandibular arch dimensions. Three linear distances were utilized on each side on the dental arch: Incisal-canine distance, can...

  20. Floating-hauling Construction Technique for Large-span,Heavy-weight Leaning-type Tied Arch Bridge%大跨度、大重量斜靠式系杆拱桥浮拖法施工技术研究



    基于100 m 跨径云梨桥斜靠式钢箱系杆拱桥工程,介绍浮拖法施工技术在大跨度、大重量偏心斜靠式系杆拱桥施工中的应用,分析系杆拱桥整体浮拖中的关键工序和控制措施,针对云梨桥浮拖过程中的复杂性,应用空间有限元分析程序,进行了关键施工阶段的应力、变形分析,解决了浮拖过程中的稳定性问题。%Based on the project of leaning-type steel-box-tied arch Yunli Bridge with 100 m span,this paper introduces the construction technology of floating-hauling method in large-span and large-weight leaning-type eccentric tied arch bridge construction,then it analyzes the application of the key working procedure in tied arch bridge during overall floating-hauling construction and its control measures.For the complexity in floating-hauling construction of Yunli Bridge,space finite ele-ment analysis program is applied to analyze the stress and deformation in the key construction stage,and it solves the stabil-ity problem in the process of floating-hauling construction.

  1. Aortic arch malformations

    Kellenberger, Christian J. [University Children' s Hospital, Department of Diagnostic Imaging, Zuerich (Switzerland)


    Although anomalies of the aortic arch and its branches are relatively uncommon malformations, they are often associated with congenital heart disease. Isolated lesions may be clinically significant when the airways are compromised by a vascular ring. In this article, the development and imaging appearance of the aortic arch system and its various malformations are reviewed. (orig.)

  2. Glossary to ARCH (GARCH)

    Bollerslev, Tim

    The literature on modeling and forecasting time-varying volatility is ripe with acronyms and abbreviations used to describe the many different parametric models that have been put forth since the original linear ARCH model introduced in the seminal Nobel Prize winning paper by Engle (1982).  The...... figure especially prominently in the ARCH literature....

  3. 基于Kriging模型的钢管混凝土连续梁拱桥有限元模型修正%CFST arch/continuous beam bridge FEM model updating based on Kriging model

    胡俊亮; 颜全胜; 郑恒斌; 崔楠楠; 余晓琳


    A new method for FEM updating based on Kriging model was developed.The Kriging model is a linear unbiased minimum variance estimation to the unknown data in a region according to some characteristic information of region’s samples which have similar features with the unknown data.This method can obtain higher accuracy predicted results based on a small number of samples.Through a planar truss FEMupdating example,the feasibility and accuracy of the Kriging model were verified.And then the Kriging model was applied to a concrete-filled-steel-tubular (CFST)arch/continuous beam bridge FEM updating and the results were compared with those by the method of genetic algorithm (GA) combined with BP neural network.The analysis results show that the Kriging model needs only a certain amount of measured frequency data for FEM updating.There is no iterative calculation like in the FEM,which will exhaust much calculation time in updating program.This method can accurately predict the modal information outside the active frequency range.The results testify the high computational efficiency,accuracy and feasibility of the method applied in actual engineering.%提出基于Kriging模型的有限元模型修正方法。Kriging模型为据区域内若干信息样品某种特征数据对该区域同类特征未知数作线性无偏、最小方差估计方法,其只用少量样本即可获得较高精度预测结果。用Kriging模型对平面桁架进行有限元模型修正,验证该方法的可行性与准确性;对一连续梁拱桥进行模型修正,并与GA算法、BP神经网络方法模型修正结果比较分析。Kriging模型仅需一定量测量频率信息即可完成模型修正,能避免修正过程中进行有限元模型迭代计算。结果表明,该方法能准确预测有效频率范围(active frequency range)外模态信息,计算效率、精度较高,可用于工程实践。

  4. Non-linear Seismic Response of CFST Arch Bridge Considering Foundation-structure Interaction%考虑地基-结构相互作用的钢管混凝土拱桥非线性地震响应

    张波; 李术才; 杨学英; 张峰; 孙国富


    The linear and non-linear seismic responses of deck type long span concrete filled steel tube (CFST) arch bridge were analyzed considering foundation-structure interaction. Taking a deck type CFST arch bridge as studying object, a 3D viscoelastic artificial boundary was constructed to simulate the radiation damping and the elasticity recovery capacity of the medium at the far field, and the whole analytic model including the foundation and arch bridge was established. Inputting the Qian'an seismic wave which has amax - 0- 2g amplitude, the linear and nonlinear seismic responses of deck type long-span CFST arch bridge were analyzed considering foundation-structure interaction. The result shows that (1) the nonlinear influences are not ignorable when analyzing the bridge seismic response displacement, the displacement and bending moments My and Mz of main arch ribs of nonlinear seismic response are bigger than those of linear seismic response analysis; (2) the lower chord axial force at springer of nonlinear seismic response analysis is a bit bigger than that of linear seismic response analysis, the lower chord axial force at mid-span of nonlinear seismic response analysis is less than that of linear seismic response analysis.%考虑地基-结构相互作用情况,研究了上承式大跨度钢管混凝土拱桥线性及非线性地震响应.以其上承式钢管混凝土拱桥为工程背景,以三维粘弹性人工边界模拟远场地基的辐射阻尼和弹性恢复性能,建立了包括基岩和上部桥梁的整体分析模型,沿纵桥向输入amax=0.2g迁安地震波,在考虑地基-结构相互作用条件下研究了上承式大跨度钢管混凝土拱桥线性及非线性地震响应.研究表明非线性行为在桥梁进行地震响应位移分析时是不可忽视的,考虑非线性后拱肋地震响应位移计算结果增大,主拱肋部分截面弯矩My、Mz大于线性计算时结果;下弦管轴力在拱脚附近非线

  5. Application of Hydraulic-Walking Incremental Launching to Steel Arch Girder Construction of Shen′an Huanghe River Bridge in Lanzhou%兰州深安黄河大桥钢拱梁步履式顶推施工技术



    The main bridge of Shen′an Huanghe River Bridge in Lanzhou is designed as a bow -string steel arch composite girder bridge with a main span of 156 m .The two arch ribs splay out-ward like a butterfly .The main girder is the steel-concrete composite girder with constant cross section .The main bridges characterized by its heavy weight and long spans ,weighs about 4 000 t after all the components are installed .The main bridge construction is likely to impose impact on the navigation channel and the transportation .Due to these reasons ,the steel arch girder is de-signed to be constructed by the hydraulic-walking incremental launching scheme and by way of multiple-point simultaneous incre mental launching .The specialist hydraulic-walking incremental launching equipment was used to carry out the overall incremental launching construction of the main bridge .During the incremental launching construction ,the truss support structure made of steel tubes was added so as to ensure that the load bearing capacity of the bridge in the incremental launching process could meet the requirements .During the construction ,the technique of incre-mental launching along varying vertical curve was adopted ,the elevation of the temporary piers was optimized and determined by optimizing the preliminary elevation and improving the equip -ment .The construction technique was made better by placing the launching nose on the piers and enhancing applicability of the positioning equipment ,achieving the goal of reducing cost and im-proving safety . The engineering experience proves that the incremental launching technique en-sured the safety of the construction process and the geometrical shape of the completed bridge meets the requirements .%兰州深安黄河大桥主桥为主跨156 m 的下承式蝶形钢拱组合梁桥,主梁为等截面钢-混凝土结合梁,主桥全部拼装完总重约4000 t 。针对主桥重量大、跨度大的特点,以及施工对航道、交通的影

  6. Application of space entity the unit model calculations in the testing of the carrying capacity of the stone arch bridge%空间实体单元模型计算在石拱桥承载能力检测试验中的应用



      Currently, domestic and international bridge design software is mostly beam element modeling. In recent years, the space grillage method is the more common.Beam elements for most of the beam bridge analysis relatively simple to apply, but the stone arch bridge analysis is not so ap-ply. Bridge calculation and analysis of the most concern is the the transverse stiffness size and load lateral distribution unit of space entity model can be used to solve this kind of problem. Testing of the carrying capacity of the stone arch bridge engineering background, space solid element modeling in detector design and application of static and dynamic load test calculations, analysis and comparison of the solid element modeling cal-culations,beam element modeling calculations as well as the results of the tests measured.%  目前,国内外桥梁计算设计软件大部分采用梁单元建模。近年来,空间梁格法应用较普遍。梁单元对于大部分梁桥分析比较简单适用,但对于石拱桥分析就不那么适用了。桥梁计算分析中最关注的是结构横向刚度大小和荷载横向分布的问题,空间实体单元模型能很好地解决这类问题。以石拱桥承载能力检测试验为工程背景,介绍了空间实体单元建模在检测方案设计和静、动载试验计算中的应用,并分析对比了实体单元建模计算结果、梁单元建模计算结果以及试验实测结果。

  7. Multivariate Rotated ARCH models

    Shephard, Neil; Sheppard, Kevin; Noureldin, Diaa


    This paper introduces a new class of multivariate volatility models which is easy to estimate using covariance targeting, even with rich dynamics. We call them rotated ARCH (RARCH) models. The basic structure is to rotate the returns and then to fit them using a BEKK-type parameterization of the time-varying covariance whose long-run covariance is the identity matrix. The extension to DCC-type parameterizations is given, introducing the rotated conditional correlation (RCC) model. Inference f...

  8. The ARCHES Project

    Motch, C.; Arches Consortium


    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

  9. Comprehensive Real-Time Bridge Health Monitoring System of Tongtai Bridge

    Lei Su-su; Gao Yong-tao; Pan Dan-guang


    Tongtai Bridge is the world’s largest suspension curve-girder-skew-arch bridge, which is located in Zhangjiakou, China. The understanding of mechanics characteristics is limited to such complex bridges, so it is necessary to establish reliable health monitoring system to investigate the static and dynamic responses and monitor the safety of the bridge. A comprehensive real-time bridge health monitoring system is establish, which includes four aspects: sensor system, data acquisition and trans...

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

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


    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.

  11. 基于行波效应的大跨度钢-混凝土组合拱桥地震响应分析%Analysis for Seismic Response of Large-span Steel-concrete Combined Arch Bridges Based on Traveling Wave Effect



    研究大跨度结构的地震响应时,有必要考虑地震波的行波效应。针对一种特殊的钢-混凝土组合拱桥进行地震响应研究。以重庆市万县长江大桥为建模依据,使用大型通用有限元软件sap2000建立跨径为420 m的钢-混凝土组合拱桥计算模型,并对该模型多种激励状态进行分析。在一致激励状态下进行几何非线性时程分析,并基于多点激振理论和相对位移法,采用7种不同的时差对计算模型进行行波效应下的地震响应分析。对比研究表明行波效应对大跨度桥梁结构地震响应有很大影响。%In research on seismic response of large -span structures , it is necessary to consider traveling wave effect of seismic wave .This paper researches seismic response in allusion to a special steel -concrete combined arch bridge .With Chongqing Wan County Yangtze River Bridge as the basis for modeling , the paper establishes a computational model of steel -concrete combined arch bridge at a span of 420 m by means of large-scale universal finite element software sap 2000, and analyzes multiple excited states of the model.The paper carries out geometric nonlinear time -history analysis in consistent excited states and seismic response analysis for the computational model under the traveling wave effect by means of 7 different time differences .Comparative research shows that traveling wave effect exhibits great influences on seismic response of structures .

  12. The ARCHES project

    Motch, C; Genova, F; Esteban, F Jiménez-; López, M; Michel, L; Mingo, B; Mints, A; Gómez-Morán, A Nebot; Pineau, F -X; Rosen, S; Sanchez, E; Schwope, A; Solano, E; Watson, M


    ARCHES (Astronomical Resource Cross-matching for High Energy Studies) is a FP7-Space funded project whose aim is to 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 DR5 X-ray catalogue of serendipitous sources. The project has developed new tools implementing fully probabilistic simultaneous cross-correlation of several catalogues for unresolved sources and a multi-wavelength finder for clusters of galaxies for extended sources. These enhanced resources have been tested in the framework of several science cases.

  13. 环境振动下的钢管混凝土拱桥试验与分析%Ambient Vibration Testing and Analysis of Concrete Filled Steel Tube Arch Bridge

    王立宪; 狄生奎; 刘云帅; 花尉攀


    环境振动试验是检测大型桥梁结构的主要方法,检测得到的模态参数是判定桥梁健康状况的重要依据.本文基于随机振动理论,从雁滩黄河大桥在环境激励下获得的加速度测试信号中提取高信噪比的响应信号,采用频域峰值法和时域随机子空间法识别得到了该桥的固有频率、阻尼比和振型等模态参数,并与有限元模型计算结果进行了对比,验证了识别结果的可靠性,结果可作为该桥的损伤检测、使用状态评估和健康监测的基础.%Ambient vibration test is the main method of detecting a large bridge structure, Modal parameters is important to determine the health status of the bridge. Based on random vibration theory, as a high signal-to-noise ratio response,virtual response is obtained from the measured acceleration signal of Yantan Yellow River Bridge of Lanzhou under ambient excitation. Yantan Yellow River bridge's modal parameters, such as natural frequency, damping ratio and mode of vibration, are identified by using the peak picking and stochastic subspace identification, and are compared with the finite element model results and verified the reliability of recognition results. The identified dynamic properties can be served as the basis in the finite element model updating, damage detection, condition assessment and health monitoring of the bridge.

  14. Strength of arch-shaped members in bending and shear

    Campana, Stefano; Fernández Ruiz, Miguel; Muttoni, Aurelio


    Arch-shaped members are widely used for construction of tunnels, bridges, silos and shells. These members are not typically provided with transverse reinforcement and may thus have a brittle behaviour at failure. When subjected to bending or shear, traditional design methods used for straight members are not applicable due to deviation forces developing at the curved chords carrying compression and tension, which is not always accounted in design codes. In this paper, two experimental series ...

  15. Simple Way of Recording Dental Arch Forms

    Gupta, Shreya; Ratre, Ram Kishore; Jain, Sandhya; Chandki, Rita


    Like finger prints each individual has a unique dental arch form design. Recording patient’s dental arch form may be required in various fields in dentistry be it longitudinal studies for evaluating growth, forensic dentistry and most importantly in orthodontic practice for fabricating arch wires for individual patients. An easy and practical method to obtain individual arch form for each patient is explained.

  16. Experimental behavior of FRP strengthened masonry arches

    Oliveira, Daniel V.; Basílio, Ismael; Lourenço, Paulo B.


    This paper deals with the experimental behavior of solid clay brick masonry arches strengthened with glass fiber reinforced polymer composites. Twelve half-scaled segmental masonry arches subjected to a load applied at the quarter span were tested under displacement control up to failure. The arches were built using handmade low strength bricks and a commercial lime-based mortar, trying to mimic ancient structures. Besides reference unreinforced arches, five different strengthening arrangemen...

  17. Persistent Fifth Aortic Arch with Coarctation

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


    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

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

    Zohreh Hedayati; Farnaz Fakhri; Vahid Moshkel Gosha


    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 Universit...

  19. Investigating the Hysteretic Behavior of Concrete-Filled Steel Tube Arch by Using a Fiber Beam Element

    Jun Ma; Yang Liu; Qingfei Gao; Kang Hou


    A fiber beam finite element that could account for the nonlinear constitutive relationship between steel and concrete was applied to investigate the hysteretic behavior of concrete filled steel tube (CFT) arch ribs of bridges. At first, the effectiveness of this fiber beam element using for nonlinear analysis was verified by comparing the analytical results with the experimental data, and then this composite element was applied to analyze the hysteretic performance of CFT arch ribs. The follo...

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

    Zohreh Hedayati


    Full Text Available 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 sub-jects. 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 nor-mal 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 arc

  1. Bridge? What's a Bridge?

    Gutsche, George


    Considers the metaphor of the "bridge" as it applies to Russian-language courses at the university level. The article examines broader curricular issues of technology, innovation, and outside pressures on language teaching. (22 references) (CK)

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

    Rakhn G. Al-Barakati


    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.

  3. Railroad Bridges

    Department of Homeland Security — Bridges-Rail in the United States According to The National Bridge Inspection Standards published in the Code of Federal Regulations (23 CFR 650.3), a bridge isA...

  4. Tranverse Deck Reinforcement for Use in Tide Mill Bridge

    Bajzek, Sasha N


    The objective of the research presented in this thesis was to study and optimize the transverse deck reinforcement for a skewed concrete bridge deck supported by Hybrid Composite Beams (HCB\\'s).  An HCB consists of a Glass Fiber Reinforced Polymer outer shell, a concrete arch, and high strength seven wire steel strands running along the bottom to tie the ends of the concrete arch together.  The remaining space within the shell is filled with foam.  The concrete arch does not need to be cast u...

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

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


    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

  6. Techniques for aortic arch endovascular repair.

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


    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

  7. Nonlinear Dynamics of Electrostatically Actuated MEMS Arches

    Al Hennawi, Qais M.


    In this thesis, we present theoretical and experimental investigation into the nonlinear statics and dynamics of clamped-clamped in-plane MEMS arches when excited by an electrostatic force. Theoretically, we first solve the equation of motion using a multi- mode Galarkin Reduced Order Model (ROM). We investigate the static response of the arch experimentally where we show several jumps due to the snap-through instability. Experimentally, a case study of in-plane silicon micromachined arch is studied and its mechanical behavior is measured using optical techniques. We develop an algorithm to extract various parameters that are needed to model the arch, such as the induced axial force, the modulus of elasticity, and the initially induced initial rise. After that, we excite the arch by a DC electrostatic force superimposed to an AC harmonic load. A softening spring behavior is observed when the excitation is close to the first resonance frequency due to the quadratic nonlinearity coming from the arch geometry and the electrostatic force. Also, a hardening spring behavior is observed when the excitation is close to the third (second symmetric) resonance frequency due to the cubic nonlinearity coming from mid-plane stretching. Then, we excite the arch by an electric load of two AC frequency components, where we report a combination resonance of the summed type. Agreement is reported among the theoretical and experimental work.

  8. Pervious concrete fill in Pearl-Chain Bridges: Using small-scale results in full-scale implementation

    Lund, Mia Schou Møller; Hansen, Kurt Kielsgaard; Truelsen, R.;


    Pearl-Chain Bridge technology is a new prefabricated arch solution for highway bridges. This study investigates the feasibility of pervious concrete as a filling material in Pearl-Chain Bridges. The study is divided into two steps: (1) small-scale tests where the variation in vertical void...

  9. On inner constraints in plane circular arches

    Ruta, G.C. [Universita di Roma ' ' La Sapienza' ' , Dipartimento di Ingegneria Strutturale e Geotecnica, via Eudossiana 18, I-00184 Roma (Italy)


    A one-dimensional model of plane circular arches with rigid sections is introduced. Suitable strain measures are defined as deviations from rigid displacements. If the arch is thin, constitutive arguments make the shearing strain negligible. Hence, the shearing indeformability will be assumed as inner constraint. By means of a formal power series expansion of the exact measures of deformation it is shown that the shearing indeformability implies some constraints on the axial strain. In particular, the first-order axial strain must vanish in the case of infinitesimal displacements. The same procedure is applied to pure flexible arches, in order to compare the two sets of results. It is shown that the hypothesis of finite pure flexibility is not compatible with small deformations of the arch. An example is provided to evaluate the effects of the two constraints at the first non-linear step of the perturbation expansions. (orig.)

  10. Congenital anomalies of aortic arch: CT angiography

    Moon, Yung; Kim, Yang Min; Kim, Tae Hoon; Kim, Mi Young [Sejong General hospial, Seoul (Korea, Republic of); Lee, Jae Young [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of); Kim, Hyung Seok [Cheju Medical Center, Cheju (Korea, Republic of)


    Aortic arch anomalies result from the failure of an embryonic vascular structure to persists and regress in the usual manner during formation of the aortic arch. The anomalous aortic arch may encircle and compress the trachea and esophagus as a form of a vascular ring. The diagnosis of aortic arch anomaly and the recognition of airway compression are important because they are conditions which complicate the natural and surgical course of related diseases. CT can demonstrate the nature of anatomic structures such as thr treachea and esophagus not revealed by angiogrphy, simultaneosuly disclosing the relationship of stenotic airways and offending mediastinal vessels. Volumetric data acquisition by means of spiral CT enables three dimensional reconstruction, which can provide easy global understanding for the complex anatomy and spatial relationship of airway and cardiovascular structures. Three dimensional imaging is very useful for the physician and surgeon who are not accustomed to mentally reconstructing axial images, and can facilitate surgical planning.

  11. Determinant factors of Yemeni maxillary arch dimensions

    Nabil Muhsen Al-Zubair


    Conclusion: Measurements of palatal depth and relationships of the canines to one another and to other teeth thus had the widest ranges, implying that these dimensions are the strongest determinants of maxillary arch size.

  12. Measurement evaluation and FEM simulation of bridge dynamics

    Andersson, Andreas; Malm, Richard


    The aim of this thesis is to analyse the effects of train induced vibrations in a steel Langer beam bridge. A case study of a bridge over the river Ljungan in Ånge has been made by analysing measurements and comparing the results with a finite element model in ABAQUS. The critical details of the bridge are the hangers that are connected to the arches and the main beams. A stabilising system has been made in order to reduce the vibrations which would lead to increased life length of the bridge...

  13. Comprehensive Real-Time Bridge Health Monitoring System of Tongtai Bridge

    Lei Su-su


    Full Text Available Tongtai Bridge is the world’s largest suspension curve-girder-skew-arch bridge, which is located in Zhangjiakou, China. The understanding of mechanics characteristics is limited to such complex bridges, so it is necessary to establish reliable health monitoring system to investigate the static and dynamic responses and monitor the safety of the bridge. A comprehensive real-time bridge health monitoring system is establish, which includes four aspects: sensor system, data acquisition and transmission system, data processing and control system, structure early warning and security assessment system. The paper systematically describes the system design principles, sensor layout, and monitoring content, then expounds system integration and function of each subsystem.

  14. Arch Index: An Easier Approach for Arch Height (A Regression Analysis

    Hironmoy Roy


    Full Text Available Background: Arch-height estimation though practiced usually in supine posture; is neither correct nor scientific as referred in literature, which favour for standing x-rays or arch-index as yardstick. In fact the standing x-rays can be excused for being troublesome in busy OPD, but an ink-footprint on simple graph-sheet can be documented, as it is easier, cheaper and requires almost no machineries and expertisation. Objective: So this study aimed to redefine the inter-relationship of the radiological standing arch-heights with the arch-index for correlation and regression so that from the later we can derive the radiographical standing arch-height values indirectly, avoiding the actual maneuver. Methods: The study involved 103 adult subjects attending at a tertiary care hospital of North Bengal. From the standing x-rays of foot, the standing navicular, talar heights were measured, and ‘normalised’ with the foot length. In parallel foot-prints also been obtained for arch-index. Finally variables analysed by SPSS software. Result: The arch-index showed significant negative correlations and simple linear regressions with standing navicular height, standing talar height as well as standing normalised navicular and talar heights analysed in both sexes separately with supporting mathematical equations. Conclusion: To measure the standing arch-height in a busy OPD, it is wise to have the foot-print first. Arch-index once get known, can be put in the equations as derived here, to predict the preferred standing arch-heights in either sex.

  15. Dental Arch Dimension of Malay Ethnic Group

    H. A. Mohammad


    Full Text Available Problem statement: Many previous studies tried to define and put specific measurements for dental arches dimension in different ethnics groups. However, these studies may be specific to an ethnic group and cannot always be applied to other ethnic types. The aim of this study: is to obtain specific dental arch dimensions for Malaysian Malay ethnic groups and compare between both genders. Approach: Involved clinical examination, collection and analysis of 60 dental cast of Malaysian Malay subjects from pure ethnic group (30 males and 30 females, 20-24 years old. All dental landmarks were located and determined and subsequently measurements had been done according to specific points have been selected. Statistical analysis were done using t-test. Results: Dental arch dimension were established in normal occlusion for Malaysian Malay ethnic group in this study. No significant difference was observed in arch dimensions between male and female of Malaysian Malay. Conclusion: These measurement should be considered during treatment, especially in prosthodontics and orthodontics where arch dimension can be modified appreciably.

  16. Myocardial Bridging.

    Yuan, Shi-Min


    Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results. PMID:27074276

  17. Myocardial Bridging

    Shi-Min Yuan


    Full Text Available Abstract Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results.

  18. The fundamental concepts of the limit design of stone arches; La verifica degli archi a conci lapidei

    Clemente, Paolo [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente


    Stone arches represent one of the most interesting topics in the field of the preservation of historic and monumental structures. The reason of this interest is related to the conservation of ancient structures, which have arrived until our age and to the relatively recent construction, especially railway bridges, of this century. In this paper the fundamental concepts of the limit design of stone arches are discussed. The simple case of funicular arch is first shown. Then the two classical shape are studied, parabolic and circular, subject to dead loads only. Finally, the effects of live loads and seismic loads are analyzed. The numerical analysis were carried out by means of computer codes. The results are plotted in diagrams to be used for the structural check.

  19. Hydatid cyst involving the aortic arch.

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


    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

  20. Kilmacduagh Cathedral, south exterior wall, door, jamb, arch and hood

    O'Donovan, Danielle


    South door jamb, arch and hood moulding. Jamb and arch moulding from intrados comprises: hollow chamfer, quadrant, hollow chamfer, right-angled rebate, hollow chamfer. The hood, from extrados comprises: frontal fillet, hollow chamfer, right-angled rebate, hollow chamfer.

  1. Congenital defects of atlantal arch. A report of eight cases

    Atlantal arch defects are rare. The purpose of this paper is to investigate the incidence and clinical implications of these, using Cervical CT with traumatic patients. A retrospective review of 1,534 cervical spine computed tomography (CT) scans was performed to identify patients with atlantal arch defects. Posterior arch defects of the atlas were grouped in accordance with the classification of Currarino et al. Posterior arch defects were found in 7 (7/1534, 0.44%) and anterior arch defects were found in 2 (2/1534, 0.13%) of the 1,534 patients. The type A posterior arch defect was found in 5 patients and the type B posterior arch defect was found in 2 patients. No type C, D, or E defects were observed. One patient with a type B posterior arch defect had an anterior atlantal-arch midline cleft. Associated cervical spine anomaly was not observed in our cases. None of the reviewed patients had neurological deficits because of atlantal arch defects. Most congenital anomalies of the atlantal arch are found incidentally during investigation of neck mass, neck pain, radiculopathy, and after trauma. Almost cases of atlantal arch defects are not need to operate. But it is important to note some cases require surgical treatment. (author)

  2. Arch Coal focuses on its future

    Arch Coal, Inc (ACI) has emerged as the second largest US coal producer, with nearly 5000 employees producing 110 million tons of coal per year. The article discusses the company's philosophy, as stated by Steve Leer, President and CEO, and reports interviews with six other senior executives talking about policy on finances, sales, marketing, business development and operations. 8 photos

  3. Bridge Management Systems

    Thoft-Christensen, Palle

    In this paper bridge management systems are discussed with special emphasis on management systems for reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way....

  4. Programmevaluierung Bridge

    Warta, Katharina; Good, Barbara; Geyer, Anton


    BRIDGE is an initiative funded by the Ministry for Transport, Innovation and Technology (BMVIT) that aims to close the “funding gap” between basic and applied research in stand-alone projects with the primary objective of jointly developing the potential of basic and applied research. BRIDGE acts as an  umbrella structure under which the Austrian Science Fund (FWF) and the  Austrian Research Promotion Agency (FFG) coordinate two thematically open funding programmes: The ...

  5. National Bridge Inventory (NBI) Bridges

    Department of Homeland Security — The NBI is a collection of information (database) describing the more than 600,000 of the Nation's bridges located on public roads, including Interstate Highways,...

  6. 乌溪江大桥方案设计%Scheme Design of Wuxijiang Bridge

    张红星; 刘德宝; 余茂峰


    乌溪江大桥为浙江省遂昌县西南部跨越乌溪江水库的一座特大型桥梁.根据桥梁建设条件、景观、造价等因素,拟定了钢管混凝土拱桥、劲性骨架混凝土拱桥、连续刚构三种桥型方案.通过综合比较,确定钢管混凝土拱桥作为推荐桥型方案.%Wuxijiang Bridge is a long span bridge across Wuxijiang Reservoir in the southwest of Suichang County, Zhejiang Province. On the basis of the conditions of bridge construction, landscape, cost and other factors, three shemes of concrete-filled steel pipe arch bridge, concrete arch bridge with stiff skeleton, continuous rigid frame bridge are put forward. Through comprehensive comparison, concrete-filled steel pipe arch bridge is determined as recommended bridge type.

  7. Biotechnologie des archées

    Querellou, Joel


    La majorité des enzymes utilisées dans l’industrie provient des bactéries et des levures. Mais les conditions extrêmes dans lesquelles se développent de nombreuses espèces d’archées font que leurs constituants cellulaires possèdent des propriétés et une stabilité propices à leur utilisation en biotechnologie.

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

    Tsai, Hung-Huey


    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

  9. Building Bridges

    The report Building Bridges adresses the questions why, how and for whom academic audience research has public value, from the different points of view of the four working groups in the COST Action IS0906 Transforming Audiences, Transforming Societies – “New Media Genres, Media Literacy and Trust...... in the Media”, “Audience Interactivity and Participation”, “The Role of Media and ICT Use for Evolving Social Relationships” and “Audience Transformations and Social Integration”. Building Bridges is the result of an ongoing dialogue between the Action and non-academic stakeholders in the field of audience...

  10. Arch Index: An Easier Approach for Arch Height (A Regression Analysis)

    Hironmoy Roy; Kalyan Bhattacharya; Samar Deb; Kuntala Ray


    Background: Arch-height estimation though practiced usually in supine posture; is neither correct nor scientific as referred in literature, which favour for standing x-rays or arch-index as yardstick. In fact the standing x-rays can be excused for being troublesome in busy OPD, but an ink-footprint on simple graph-sheet can be documented, as it is easier, cheaper and requires almost no machineries and expertisation. Objective: So this study aimed to redefine the inter-relationship of the radi...

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

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


    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 polynomia...

  12. In-plane elastic stability of fixed parabolic shallow arches


    The nonlinear behavior of fixed parabolic shallow arches subjected to a vertical uniform load is inves- tigated to evaluate the in-plane buckling load. The virtual work principle method is used to establish the non-linear equilibrium and buckling equations. Analytical solutions for the non-linear in-plane sym- metric snap-through and antisymmetric bifurcation buckling loads are obtained. Based on the least square method, an approximation for the symmetric buckling load of fixed parabolic arch is proposed to simplify the solution process. And the relation between modified slenderness and buckling modes are discussed. Comparisons with the results of finite element analysis demonstrate that the solutions are accurate. A cable-arch structure is presented to improve the in-plane stability of parabolic arches. The comparison of buckling loads between cable-arch systems and arches only show that the effect of cables becomes more evident with the increase of arch’s modified slenderness.

  13. Three-dimensional measurement of foot arch in preschool children

    Chang Hsun-Wen; Lin Chien-Ju; Kuo Li-Chieh; Tsai Ming-June; Chieh Hsiao-Feng; Su Fong-Chin


    Abstract Background The prevalence of flexible flatfoot is high among preschool-aged children, but the effects of treatment are inconclusive due to the unclear definitions of normal flatfoot. To date, a universally accepted evaluation method of the foot arch in children has not been completely established. Our aims of this study were to establish a new method to evaluate the foot arch from a three dimensional perspective and to investigate the flexibility of the foot arch among children aged ...

  14. Three-dimensional measurement of foot arch in preschool children

    Chang, Hsun-Wen; Lin, Chien-Ju; Kuo, Li-Chieh; Tsai, Ming-June; Chieh, Hsiao-Feng; Su, Fong-Chin


    Background The prevalence of flexible flatfoot is high among preschool-aged children, but the effects of treatment are inconclusive due to the unclear definitions of normal flatfoot. To date, a universally accepted evaluation method of the foot arch in children has not been completely established. Our aims of this study were to establish a new method to evaluate the foot arch from a three dimensional perspective and to investigate the flexibility of the foot arch among children aged from two ...

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

    Austin, J H; Thorsen, M K


    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

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

    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

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

    Austin, J.H.M. (Columbia-Presbyterian Medical Center, New York); Thorsen, M.K.


    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.

  18. Monitoring of arched sched ground layer

    Arched Shed was a part of controlled area of NPP A1 site in Jaslovske Bohunice (Slovakia). It had been used for temporary storage of loose radioactive waste (RAW) which has been characterized within the BIDSF project C13, Characterisation of Loose Radioactive Waste'. Stored RAW has been treated and sorted within the project ',Realization of the 2nd stage of Decommissioning Project of NPP A1'. Area of Arched Shed represents approximately 270 m2 (45 m x 6 m). Ground layer of the AS consists mostly of soil with solid elements (stones and gravel). The aim of monitoring was to remove the contaminated soil up to 1 m below ground level. Requirement for detail monitoring of the Arched Shed ground layer resulted from conclusions of the BIDSF project C13 which has proved that massic activity 137Cs of soil was up to few thousands Bq·kg-1 in underground layer. Dominant easy to measure radionuclide in the soil is 137Cs which has been used as a key radionuclide for methodology of in-situ soil monitoring. Following methods has been applied during characterization: dose rate survey, sampling from defined ground layer followed by laboratory gamma spectrometry analysis by the accredited testing laboratory of radiation dosimetry VUJE (S-219) and in-situ scintillation gamma spectrometry by 1.5''x1.5'' LaBr detector. Massic activity of the remaining soil (not excavated) comply the criteria for free release into the environment (Government Regulation of Slovak Republic 345/2006 Coll.). Area was filled up by non-contaminated soil up to the ground level of surroundings. Afterward the area was covered with geotextile and concrete panels and nowadays it is ready for further usage within the NPP A1 decommissioning project as a place for treatment, conditioning and disposal of contaminated soil and concrete. (authors)

  19. A Functional Version of the ARCH Model

    Hormann, Siegfried; Reeder, Ron


    Improvements in data acquisition and processing techniques have lead to an almost continuous flow of information for financial data. High resolution tick data are available and can be quite conveniently described by a continuous time process. It is therefore natural to ask for possible extensions of financial time series models to a functional setup. In this paper we propose a functional version of the popular ARCH model. We will establish conditions for the existence of a strictly stationary solution, derive weak dependence and moment conditions, show consistency of the estimators and perform a small empirical study demonstrating how our model matches with real data.

  20. Stone bridges

    Drdácký, Miloš; Slížková, Zuzana

    Prague : Institute of theoretical and applied mechanics AS CR, v.v.i, 2011 - (Drdácký, M.; Binda, L.; Hennen, I.; Kőpp, C.; Lanza, L.), s. 122-129 ISBN 978-80-86246-37-6 Grant ostatní: evropská komise(XE) CHEF-SSPI-044251 Institutional research plan: CEZ:AV0Z20710524 Keywords : flood * stone bridge * cultural heritage Subject RIV: AL - Art, Architecture, Cultural Heritage

  1. Three-dimensional measurement of foot arch in preschool children

    Chang Hsun-Wen


    Full Text Available Abstract Background The prevalence of flexible flatfoot is high among preschool-aged children, but the effects of treatment are inconclusive due to the unclear definitions of normal flatfoot. To date, a universally accepted evaluation method of the foot arch in children has not been completely established. Our aims of this study were to establish a new method to evaluate the foot arch from a three dimensional perspective and to investigate the flexibility of the foot arch among children aged from two to six. Methods A total of 44 children aged from two to six years of age were put into five age groups in this study. The navicular height was measured with one leg standing, and both feet were scanned separately in both sitting and one leg standing positions to compute the foot arch volume. The arch volume index, which represents the ratio of the difference in volume between sitting and one leg standing positions to the volume when sitting was calculated to demonstrate the flexibility of the foot arch. The differences of measured parameters between each aged group were analyzed by one-way ANOVA. Results The arch volumes when sitting and standing were highly correlated with the navicular height. The navicular height ranged from 15.75 to 27 mm, the arch volume when sitting ranged from 6,223 to 11,630 mm3, and the arch volume when standing from 3,111 to 7,848 mm3 from two to six years of age. The arch volume index showed a declining trend as age increased. Conclusion This study is the first to describe the foot arch with volume perspective in preschool-aged children. The foot arch volume was highly correlated with the navicular height. Research results show both navicular height index and arch volume index gradually increase with age from two to six. At the same time the arch also becomes rigid with age from two to six. These results could be applied for clinical evaluation of the foot arch and post-treatment evaluation.

  2. Cathodic Protection of the Yaquina Bay Bridge

    Bullard, Sophie J.; Cramer, Stephen D.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Russell, James H.; Laylor, H.M.; Cryer, C.B.


    The Yaquina Bay Bridge in Newport, Oregon, was designed by Conde B. McCullough and built in 1936. The 3,223-foot (982 m) structure is a combination of concrete arch approach spans and a steel through arch over the shipping channel. Cathodic protection is used to prevent corrosion damage to the concrete arches. The Oregon Department of Transportation (Oregon DOT) installed a carbon anode coating (DAC-85) on two of the north approach spans in 1985. This anode was operated at a current density of 6.6 mA/m2(0.6 mA/ft2). No failure of the conductive anode was observed in 1990, five years after application, or in 2000, 15 years after application. Thermal-sprayed zinc anodes 20 mils (0.5 mm) thick were applied to half the south approach spans beginning in 1990. Thermal-sprayed zinc anodes 15 mils (0.4 mm) thick were applied to the remaining spans in 1996. These anodes were operated at a current density of 2.2 mA/m2(0.2 mA/ft2). In 1999, four zones on the approach spans were included in a two-year field trial of humectants to improve zinc anode performance. The humectants LiNO3 and LiBr were applied to two zones; the two adjacent zones were left untreated as controls. The humectants substantially reduced circuit resistance compared to the controls.

  3. Isolated right aortic arch: Antenatal evaluation

    Ali Babacan


    Full Text Available Aortic arch abnormalities are the least frequently prenatally diagnosed congenital cardiac abnormalities. Right aortic arch (RAA identified in prenatal period is associated frequently with other cardiac/non-cardiac malformations, notably tracheal or esophageal compression and microdeletions 22q11. Intrauterine and postnatal survey of the fetus depends on these anomalies and their effects. Aortic arc variations, particularly RAA, can be diagnosed accurately by fetal echocardiography. Elaborated fetal cardiac and extracardiac evaluation should be undertaken in all cases of RAA by using Doppler ultrasound. Also cytogenetic testing for 22q11 microdeletions should be considered carefully. Nonetheless, it should be kept in mind that isolated RAA has a good prognosis, and in the majority of the patients, it is an asymptomatic vascular variant with a relatively low risk for chromosomal anomaly. In this paper with this case, we aim to evaluate the prenatal findings, associated conditions and prognosis of prenatally detected RAA anomalies in the light of literatures. J Clin Exp Invest 2015; 6 (2: 192-195

  4. Wildlife use of existing culverts and bridges in North Central Pennsylvania

    Brudin, Carl O. III


    The Pennsylvania Department of Transportation (PENNDOT) District 3-0 initiated a study in North Central Pennsylvania evaluating existing bridges and culverts for use as underpasses by wildlife. This project was a two-phase study to investigate animal passage through existing drainage box culverts, arch culverts and bridges on existing highway systems. The objective of this study was to (1) determine whether wildlife are using existing structures as passageways based on wildlife sign and remot...


    Nassar, Mohammad


    This article provides a study of Hadrian arches from three main locations: Jordan, Turkey, and Greece. Collectively within these countries, four arches have been found the Hadrian arch at Jerash (Gerasa) in Jordan, the Hadrian arch in Antalya and Ephesus, both in Turkey, and the Hadrian arch in Athens, Greece. The units of our analysis include all the different designs and plans used in constructing these arches. The analyzed design and planning units constitute a database that enables the...

  6. Arch Height: A Regression Analysis of Different Measuring Parameters

    Hironmoy Roy


    Full Text Available Rationale: For measuring the height of the arch of foot either standing navicular height or talar height of the medial longitudinal arch was accepted in earlier days, where as the ‘standing normalised navicular height’ is taken by modern day by authors as a yardstick. But being troublesome and time consuming, we practically not opt for them in busy OPD schedule; rather go for measuring the arch-height in supine posture. Objectives: So this study was aimed to derive the regression between the standing arch-height values with the supine counterparts, so that former can be predicted easily from later. Methodology: It was carried out among 103 adult subjects in the purview of North Bengal Medical College & Hospital. From the x-ray films of their feet in supine and standing posture the navicular and talar heights were determined and the records were analysed. Result: Statistically significant correlation followed by regression analysis could reveal simple linear regression-equations for predicting the standing arch-height values from the supine values; derived separately in both males and females. Conclusion: Thus, from a known supine arch-height value, we can derive the respective standing arch- height, as well as the ‘standing normalised navicular height’ indirectly avoiding the entire troublesome maneuver in regular practice. So the present study recommends this method in clinical fields as because this is more rational and ideal approach to estimate arch height.

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

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


    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

  8. Level-ARCH Short Rate Models with Regime Switching

    Christiansen, Charlotte

    This paper introduces regime switching volatility into level- ARCH models for the short rates of the US, the UK, and Germany. Once regime switching and level effects are included there are no gains from including ARCH effects. It is of secondary importance exactly how the regime switching is spec...

  9. Modelling subset multivariate ARCH model via the AIC principle


    In this paper we consider the problem of identifying a parsimonious subset multivariate ARCH model based on the AIC principle. The proposed approach can reduce the number of parameters in the final ARCH specification and allows for non-constant correlations between the components. Some simulation results illustrate the viability of the proposed procedure.

  10. Quin Franciscan Friary, west door jamb, arch and hood

    O'Donovan, Danielle


    West door jamb, arch and hood moulding. From intrados, moulding comprises: quadrant, hollow chamfer, right-angled rebate, hollow chamfer, quadrant. The hood comprises: hollow, free-standing fillet, hollow, chamfer. This door, with its pointed arch contained within a square moulded label, is very similar in design to that at Bishopsquarter. The moulding is identical.

  11. Dunsoghly Castle Chapel, door jamb, arch and hood

    O'Donovan, Danielle


    Door jamb, arch and hood of the detatched castle chapel. Jamb and arch moulding from intrados comprise: hollow chamfer, right-angled rebate, quadrant. The hood, which is placed at some distance from the jamb, comprises from outside in: frontal fillet, hollow chamfer, right-angled rebate, hollow chamfer.

  12. Swallowing threshold parameters of subjects with shortened dental arches.

    Kreulen, C.M.; Witter, D.J.; Tekamp, F.A.; Slagter, A.P.; Creugers, N.H.J.


    OBJECTIVES: To quantify swallowing threshold parameters of subjects with a moderate shortened dental arch dentition (SDA: missing molar teeth, but premolar teeth in occluding position and uninterrupted anterior regions) compared to subjects with a complete dental arch dentition (CDA). METHODS: Fourt

  13. Seismic multi-arch structures in East China

    YANG; Wencai; CHEN; Zhide


    In previous papers (Wencai, 2002, 2003), the author has analyzed the deep seismic reflection profiles along some of the Mesozoic plutons in East China, and has pointed out that the crustal structures around these intrusions usually correlate with a special seismic fabric called the seismic multi-arch structure. This paper will continue to show main characteristics of the seismic multi-arch structures and discuss their relationship with mantle-origin magmatism and the lithospheric thinning process. Calibration of seismic reflectors in Chinese continental drilling sites shows that small-scale arch-like reflectors can be generated by fractured eclogites or other plutons, they do not belong to the multi-arch structure specially discussed in the paper. The multi-arch structure is characterized by several arch-like reflectors distributed in both the upper and lower crust with granitoid plutons or stocks exposed on the surface, which do not have obvious negative Europium anomalies. Based on the distribution pattern of arch reflectors, the multi-arch magmatic structures can be divided into three main types, namely the simple vertical combination type, the spread arch magmatic structure and the arch-bouquet structure. All of them correlate to mantle-origin magmatism, but occur in different places. The spread arch magmatic structures occur within a Mesozoic/Cenozoic rift zone with very thin and hot lithosphere. The vertical combination type of the multi-arch structures occurred near the rift zones where lithosphere was thin and hot. The arch-bouquet magmatic structures occur far from the rift zones where the lithosphere is not hot. The continental rifting acted as the late episode of the lithospheric thinning process seeing that the rift zones usually coincide with the thinnest parts of the lithosphere in East China. In different locations within the lithospheric thinning areas, mantle-origin magmatic activities have different characteristics, which might generate different

  14. Panorama de l’archéologie castrale en France

    Élise Boucharlat


    Full Text Available Aux originesOn ne saurait se livrer, en cette année 2009, à quelque réflexion que ce soit sur l’archéologie du château en France sans évoquer le cinquantenaire de la création du Centre de recherches en archéologie médiévale de Caen par le doyen Michel de Boüard. Lui qui a le plus précocement contribué à asseoir la reconnaissance académique de l’archéologie médiévale française était dans le même temps l’archéologue du château de Caen, de Doué-la-Fontaine... Une approche réellement archéologiqu...

  15. Effect of Obesity on Arch Index in Young Adults

    Sneha Sameer Ganu


    Full Text Available Background: Excessive increases in weight bearing forces caused by obesity may negatively affect the lower limbs and feet but minimal research has examined the long-term loading effects of obesity on the musculoskeletal system, particularly in reference to the feet. Objectives: The purpose of the study was to investigate the effect of obesity on medial longitudinal arch of foot in young adults. Method: 60 subjects, 30 obese & 30 non obese were assessed for height & weight using standard technique. Radiographic images under static condition were used for calculating the arch index. Result: The arch index of obese subjects was significantly lower than the non obese subjects & there is a negative correlation between the BMI & the arch index. Conclusion: These results suggests that obesity lowers the medial longitudinal arch of foot.

  16. Left testicular artery arching over the ipsilateral renal vein

    Munekazu Naito; Hayato Terayama; Yoichi Nakamura; Shogo Hayashi; Takayoshi Miyaki; Masahiro Itoh


    Aim: To report two cases of the left testicular artery arching over the left renal vein (LRV) before running downward to the testis. Methods: The subjects were obtained from two Japanese cadavers. During the student course of gross-anatomical dissection, the anatomical relationship between the testicular vessels and the renal vein was specifically observed. Results: The arching left testicular artery arose from the aorta below the LRV and made a loop around the LRV, which appeared to be mildly compressed between the arching artery and the psoas major muscle.Conclusion: Clinically, compression of the LRV between the abdominal aorta and the superior mesenteric artery occasionally induces LRV hypertension, resulting in varicocele, orthostatic protenuria and hematuria. Considering that the incidence of a left arching testicular artery is higher than that of a right one, an arching left artery could be an additional cause of LRV hypertension.

  17. Seismic behavior of concrete filled steel tubular arch structures

    Xiong Feng; Sashi K Kunnath; Liu Haowu


    Shaking table tests of a 1:10 scale arch model performed to investigate the seismic behavior and resistance of concrete filled steel tubular (CFT) arch structures are described in this paper. The El-Centro record and Shanghai artificial wave were adopted as the input excitation. The entire test process can be divided into three stages depending on the lateral brace configurations, i.e., fully (five) braced, two braces removed, and all braces removed. A total of 46 tests, starting from the elastic state to failure condition, have been conducted. The natural vibration frequencies, responses of acceleration,displacement and strain were measured. From the test results, it is demonstrated that the CFT arch structures are capable of resisting severe ground motions and that CFT arches offer a credible alternative to reinforced concrete arches, especially in regions of high seismic intensity.

  18. 紧水滩大桥桥型方案设计%The Bridge Type Design Scheme of Jinshuitan Bridge

    杨成峰; 邱白


    This paper introduces the design scheme of bridge type of Jinshuitan Bridge, compares the three kinds of schemes of the deck concrete arch bridge, prestressed concrete T beams and prestressed concrete continuous rigid frame bridge, and gi-ves the relevant conclusions and recommendations. Its design experience can be used for reference in the professional design personnel.%本文介绍了紧水滩大桥的桥型方案设计,比较了上承式混凝土拱桥、预应力砼 T 梁及预应力砼连续刚构等三种桥型方案,并给出相关结论和建议。其设计经验可供专业设计人员参考。

  19. Mission archéologique islamique

    Claire Hardy-Guilbert


    Full Text Available La troisième mission exploratoire du programme de recherches archéologiques sur la période islamique au Yémen s'est déroulée du 1 au 22 décembre 1995, en collaboration avec le Dr Ahmad Bataya, et a porté sur la côte méridionale, entre Abyan et Sayhut. Outre une étude approfondie de la ville d'al-Shihr, les prospections ont porté sur les régions d'Abyan, Ahwar et Sayhut. Prospection de la côte : Si Aden-même, le plus grand port yéménite depuis le 10ème siècle, est aujourd'hui trop urba...

  20. Implant restoration of edentulous jaws with 3D software planning, guided surgery, immediate loading, and CAD-CAM full arch frameworks

    Silvio Mario Meloni; Giacomo De Riu; Milena Pisano; Francesco Maria Lolli; Alessandro Deledda; Guglielmo Campus; Antonio Tullio


    Purpose. The aim of this study was to analyze the clinical and radiographic outcomes of 23 edentulous jaws treated with 3D software planning, guided surgery, and immediate loading and restored with CAD-CAM full arch frameworks. Materials and Methods. This work was designed as a prospective case series clinical study. Twenty patients have been consecutively rehabilitated with an immediately loaded implant supported fixed full prosthesis. A total of 120 fixtures supporting 23 bridges were place...

  1. Bovine aortic arch: A novel association with thoracic aortic dilation

    Aim: To investigate whether there is a link between bovine arch and thoracic aortic aneurysm. Materials and methods: Computed tomography (CT) and magnetic resonance imaging (MRI) images of the thorax of 191 patients with dilated thoracic aortas and 391 consecutive, unselected patients as controls were retrospectively reviewed. Bovine arch was considered present if either a shared origin of the left common carotid and innominate arteries or an origin of the left common carotid from the innominate artery was identified. A chi-square test was used to evaluate the significance of differences between subgroups. Results: A trend towards increased prevalence of bovine arch was seen in patients with dilated aortas (26.2%) compared to controls (20.5%, p = 0.12). The association was statistically significant in patients over 70 years old (31.9%, p = 0.019) and when dilation involved the aortic arch (47.6%, p = 0.003). Conclusions: An association between bovine arch and aortic dilation is seen in older patients, and when dilation involves the aortic arch. Bovine arch should be considered a potential risk factor for thoracic aortic aneurysm.

  2. Arch Height: A Regression Analysis of Different Measuring Parameters

    Hironmoy Roy; Kalyan Bhattacharya; Asit Chandra Roy; Samar Deb; Kuntala Ray


    Rationale: For measuring the height of the arch of foot either standing navicular height or talar height of the medial longitudinal arch was accepted in earlier days, where as the ‘standing normalised navicular height’ is taken by modern day by authors as a yardstick. But being troublesome and time consuming, we practically not opt for them in busy OPD schedule; rather go for measuring the arch-height in supine posture. Objectives: So this study was aimed to derive the regression between the...

  3. Statistical inference in semiparametric locally stationary ARCH models

    Truquet, Lionel


    In this paper, we develop a complete methodology for semiparametric inference in the time-varying ARCH model (tv-ARCH) introduced by Dahlhaus and Rao (2006) and studied by Fryzlewicz et al. (2008). Our first motivation is to detect and estimate non time-varying coefficients in a tv-ARCH process. Using kernel estimation, we construct $\\sqrt{T}-$consistent estimates for non time-varying coefficients and, with a two-step procedure, asymptotically efficient estimates in the semiparametric sense w...

  4. Tilted Implants for Full-Arch Rehabilitations in Completely Edentulous Maxilla: A Retrospective Study

    Nicolò Cavalli


    Full Text Available Purpose. The aims of this study were to assess the treatment outcome of immediately loaded full-arch fixed bridges anchored to both tilted and axially placed implants in the edentulous maxilla and to evaluate the incidence of biological and prosthetic complications. Materials and Methods. Thirty-four patients (18 women and 16 men were included in the study. Each patient received a maxillary full-arch fixed bridge supported by two axial implants and two distal tilted implants. A total of 136 implants were inserted. Loading was applied within 48 hours of surgery and definitive restorations were placed 4 to 6 months later. Patients were scheduled for followup at 6, 12, 18, and 24 months and annually up to 5 years. At each followup plaque level and bleeding scores were assessed and every complication was recorded. Results. The overall follow-up range was 12 to 73 months (mean 38.8 months. No implant failures were recorded to date, leading to a cumulative implant survival rate of 100%. Biological complications were recorded such as alveolar mucositis (11.8% patients, peri-implantitis (5.9% patients, and temporomandibular joint pain (5.9% patients. The most common prosthetic complications were the fracture or detachment of one or multiple acrylic teeth in both the temporary (20.6% patients and definitive (17.7% patients prosthesis and the minor acrylic fractures in the temporary (14.7% patients and definitive (2.9% patients prosthesis. Hygienic complications occurred in 38.2% patients. No patients’ dissatisfactions were recorded. Conclusions. The high cumulative implant survival rate indicates that this technique could be considered a viable treatment option. An effective recall program is important to early intercept and correct prosthetic and biologic complications in order to avoid implant and prosthetic failures.

  5. Arch development with trans-force lingual appliances.

    Clark, William J


    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

  6. Rathbourney church, south door, jamb, arch and hood moulding

    O'Donovan, Danielle


    Door jamb and arch moulding comprises, from intrados: hollow chamfer, hollow chamfer, right-angled rebate, quadrant, quadrant. The hood comprises, from outward in: frontal fillet, frontal fillet, hollow chamfer.

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

    Gardner, R B


    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

  8. Comparison of arch forms between Turkish and North American

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


    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 ...

  9. Clarifying the anatomy of the fifth arch artery

    Saurabh Kumar Gupta


    Full Text Available 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.

  10. Comparison of arch forms between Turkish and North American

    Ahmet A. Celebi


    Full Text Available 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.

  11. Developmental feature of the lumbosacral vertebral arch in childhood

    We investigated a developmental feature of the lumbosacral vertebral arch in childhood that has rarely been reported previously. Sixty-seven patients underwent functional posterior rhizotomy from September 2000 to June 2006 at National Center for Child Health and Development. Sixty of these patients, who had no deformity in their lumbosacral spine, were included in this study and their Computed Tomography (CT) images were analyzed retrospectively. There were 36 boys and 24 girls, aged from 2-12 years. The rate and mean number of non-union vertebral arches between L1 and S3 were 78.3% (95% CI, 65.8-87.9%) and 1.7 (standard deviation (SD), 1.3). The non-union arch was most frequently found at the S1 level, and was more significantly observed in the younger age group (2-5 years of age). The S4 and S5 arches, which often remained open as the sacral hiatus, were constantly open in childhood. This study demonstrates that the vertebral arches of the lumbosacral spine in normal development are often not fused during childhood. It is important to differentiate normal non-union arches from pathological spina bifida. (author)

  12. Cable Supported Bridges

    Gimsing, Niels Jørgen

    Cable supported bridges in the form of suspension bridges and cable-stayed bridges are distinguished by their ability to overcome large spans.The book concentrates on the synthesis of cable supported bridges, covering both design and construction aspects. The analytical part covers simple methods...

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

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


    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

  14. Classification of the height and flexibility of the medial longitudinal arch of the foot

    Nilsson, Mettte Kjaergaard; Friis, Rikke; Michaelsen, Maria Skjoldahl;


    BACKGROUND: The risk of developing injuries during standing work may vary between persons with different foot types. High arched and low arched feet, as well as rigid and flexible feet, are considered to have different injury profiles, while those with normal arches may sustain fewer injuries....... CONCLUSIONS: The cut-off values presented in this study can be used to categorize people performing standing work into groups of different foot arch types. The results of this study are important for investigating a possible link between arch height and arch movement and the development of injuries....




    @@ 拱,作为一种结构,在荷载作用下主要承受轴向压力,用拱券或拱肋作为主要承重结构的桥梁称为拱桥.显然,受压性能极好的石拱桥是历史上最先发展的桥梁之一.在古代,拱桥起源于模仿石灰岩溶洞中天然形成的"天生桥".据说美索不达米亚(Mesopotamia,中亚底格里斯河和幼发拉底河流域间的古王国,现今伊拉克所在地)人,曾在古罗马人建造石拱桥以前的2000多年,就造过这种桥梁.

  16. Experiment on interface separation detection of concrete-filled steel tubular arch bridge using accelerometer array

    Pan, Shengshan; Zhao, Xuefeng; Zhao, Hailiang; Mao, Jian


    Based on the vibration testing principle, and taking the local vibration of steel tube at the interface separation area as the study object, a real-time monitoring and the damage detection method of the interface separation of concrete-filled steel tube by accelerometer array through quantitative transient self-excitation is proposed. The accelerometers are arranged on the steel tube area with or without void respectively, and the signals of accelerometers are collected at the same time and compared under different transient excitation points. The results show that compared with the signal of compact area, the peak value of accelerometer signal at void area increases and attenuation speed slows down obviously, and the spectrum peaks of the void area are much more and disordered and the amplitude increases obviously. whether the input point of transient excitation is on void area or not is irrelevant with qualitative identification results. So the qualitative identification of the interface separation of concrete-filled steel tube based on the signal of acceleration transducer is feasible and valid.

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

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


    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

  18. Studies on Technical Development of Railway Steel-Concrete Composite Cirider Bridges in China


    Steel-concrete composite girder bridge boasts the advantages of strong rigidity,low noise and low construction height.Along with the large-scale construction of passengerdedicated lines (PDL) and high-speed lines (HSL),tests and researches on steel-concrete composite girder bridges have been conducted with the main types of which including steel plate girder-concrete composite girder bridge,deck steel truss girder-concrete composite girder bridge,through steel truss girder-concrete composite girder bridge and through type tied arch composite girder bridge.Based on the application and researches on steel-concrete composite technology and in combination with the engineering construction of railway bridges,the construction of HSL and PDL and upgrading of existing lines for speed-up in China,this paper analyzes the main structural forms of through steel truss girder-concrete composite girder bridges with different spans and structure systems,carries out studies on the force acted upon these bridges and the related theory and methods for design and computation,and puts forward the solutions required in relation to the key technologies for further development of railway steel-concrete composite girder bridges.

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

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


    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

  20. Game model of safety monitoring for arch dam deformation


    Arch dam deformation is comprehensively affected by water pressure,temperature,dam’s structural behavior and material properties as well as other factors.Among them the water pressure and temperature are external factors(source factors) that cause dam deformation,and dam’s structural behavior and material properties are the internal factors of deformation(resistance factors).The dam deformation is the result of the mutual game playing between source factors and resistance factors.Therefore,resistance factors of structure and materials that reflect resistance character of arch dam structure are introduced into the traditional model,where structure factor is embodied by the flexibility coefficient of dam body and the maximum dam height,and material property is embodied by the elastic modulus of dam.On the basis of analyzing the correlation between dam deformation and resistance factors,the game model of safety monitoring for arch dam deformation is put forward.


    Jyothi K C


    Full Text Available Introduction: The axillary arch muscle of Langer is the most common anatomical variant of axillary musculature which is of clinical and surgical importance. It may lead to neurovascular compression syndrome in the cervicoaxillary region and can be misinterpreted while examining axilla and also impairs movements of shoulder joint. Observation: During routine dissection of axilla for undergraduate teaching, an unusual muscular slip in the left axilla was observed .The muscular slip was extending from lattisimus dorsi muscle to undersurface of pectoralis major muscle, arching over axillary vessels and cords of brachial plexus. Conclusion: The axillary arch may cause obstruction to axillary vessels and nerves and may be involved in thoracic outlet syndrome and shoulder instability. The knowledge of this muscular variant could help to minimize intraoperative complications related to surgeries in or nearby axilla such as mastectomy, breast reconstruction and axillary lymphadenectomy or lymph node biopsy.

  2. 淦河桥梁方案设计研究%Design and Research on Bridge Scheme of Gan River



    Following the principal of applicable,economical,safe and beautiful and taking the bridge crossing Gan River in Jingui west road in Xianning City as the engineering background,four types of bridge design schemes are introduced,namely simple supported girder bridge,continuous girder bridge,through tied-arch bridge,and cable-stayed bridge without backstays.The tied arch bridge is chosen as the recommended proposal by taking bridge design,landscape feature,construction feasibil-ity and economy into comprehensive consideration.%遵循“适用、经济、安全、美观”的桥梁设计基本原则,以咸宁市金桂西路跨淦河大桥为工程背景,提供了4种桥梁设计方案:无背索斜拉桥,预应力混凝土连续梁桥、预应力混凝土简支 T梁桥、下承式系杆拱桥。综合考虑论证桥梁构造设计、景观特色、施工可行性和经济性等因素,选取下承式系杆拱桥作为推荐方案。

  3. Optical silencing of C. elegans cells with arch proton pump.

    Ayako Okazaki

    Full Text Available BACKGROUND: Optogenetic techniques using light-driven ion channels or ion pumps for controlling excitable cells have greatly facilitated the investigation of nervous systems in vivo. A model organism, C. elegans, with its small transparent body and well-characterized neural circuits, is especially suitable for optogenetic analyses. METHODOLOGY/PRINCIPAL FINDINGS: We describe the application of archaerhodopsin-3 (Arch, a recently reported optical neuronal silencer, to C. elegans. Arch::GFP expressed either in all neurons or body wall muscles of the entire body by means of transgenes were localized, at least partially, to the cell membrane without adverse effects, and caused locomotory paralysis of worms when illuminated by green light (550 nm. Pan-neuronal expression of Arch endowed worms with quick and sustained responsiveness to such light. Worms reliably responded to repeated periods of illumination and non-illumination, and remained paralyzed under continuous illumination for 30 seconds. Worms expressing Arch in different subsets of motor neurons exhibited distinct defects in the locomotory behavior under green light: selective silencing of A-type motor neurons affected backward movement while silencing of B-type motor neurons affected forward movement more severely. Our experiments using a heat-shock-mediated induction system also indicate that Arch becomes fully functional only 12 hours after induction and remains functional for more than 24 hour. CONCLUSIONS/SGNIFICANCE: Arch can be used for silencing neurons and muscles, and may be a useful alternative to currently widely used halorhodopsin (NpHR in optogenetic studies of C. elegans.

  4. Planning and Analysis of an Arched Indoor Stadium

    Alice T V


    Full Text Available This paper deals with planning and designing of a multilevel indoor stadium with hanging table tennis court and Olympic standard swimming pool. In order to support the large span the stadium is designed as an arched structure. The materials for the construction are chosen so as to have a minimum carbon di-oxide foot print. Static and earthquake analysis were done by using STAAD.Pro V8i. The paper also does a comparison between arched structure and plane frame structure.

  5. Computed tomography of the venous structure along the aortic arch

    Computed tomography has proved useful in detecting enlarged aortic arch lymph nodes. Along the aortic arch are there veins which simulate lymph nodes. They include left superior intercostal vein, persistent left superior vena cava and vertical vein. Of 526 mediastinal computed tomograms, 23 (4.4%) showed one or more para-aortic nodular shadows. These shadows were classified into three types according to the shape and number. The left superior intercostal vein appeared as a curvilinear or rounded shadow. Two or more nodular shadows are most likely to be lymph nodes. A single nodular shadow represents either lymph node or vein. (author)

  6. 福建廊桥的形态与文化研究%Research on the morphology and culture of Fujian covered bridges



    福建廊桥尤其木拱廊桥造型美观、结构科学,具有鲜明的地方特色和重要的文物价值。从福建廊桥的结构、功能入手,分析平梁木廊桥、八字撑木廊桥、木拱廊桥、石拱廊桥的类型特征,总结廊桥丰富的文化内涵,提出福建廊桥的研究内容和方向。%The Fujian covered bridges, especially the wooden arched covered bridges, are beautiful with scientific structures. They have distinctive local features and important cultural values. This paper analyzes the structural typology of the flat beam covered bridges, the Chinese- Eight-type tie covered bridges, the wooden arched covered bridges and the stone arched covered bridges through structures and functions. It summarizes the abundant cultural values of the covered bridges, and suggests the future research content and orientation.

  7. Loughrea Carmelite Friary, exterior west wall, door, jamb, arch and hood

    O'Donovan, Danielle


    Jamb, arch and hood moulding of west door. Jamb and arch moulding, from intrados, comprises: quadrant, hollow chamfer, quadrant. Hood, from exterior to interior, comprises: broad frontal fillet, hollow chamfer, quadrant, hollow chamfer.

  8. Influence of space of double row piles on soil arching effect

    Zhao bo


    Full Text Available FLAC3d software, based on continuous theory, is used to analysis influence of space of double row piles on soil arching effect. The result shows that different from single row pile, double row piles will produce soil arching effect at front pile and rear pile severally, this phenomenon is called multiple soil arching effect; the residual load of front of front row pile will increase,the soil arch zone and the soil arching effect will decrease with the continuous increase of double row pile spacing.At the same time the soil arching effect of rear pile decreases, while the soil arching effect of front pile increases and finally the soil arching effect between front pile and rear pile will be equal.

  9. The surgical importance of an axillary arch in sentinel node biopsy.

    Ridgway, P F


    When Carl Langer described the aberrant axillary arch in 1846 its relevance in sentinel node biopsy (SNB) surgery could not have been contemplated. The authors define an incidence and elucidate relevance of the arch in SNB of the axilla.

  10. Rock-Arch Instability Characteristics of the Sandstone Plate under Different Loading Conditions

    Shuren Wang; Paul Hagan; Baowen Hu; Kanchana Gamage; Cheng Yan; Dianfu Xu


    Under the concentrated loading and the uniform loading, the tests on the brittle fracture and the hinged arching until the rock-arch instability of the sandstone plate were conducted using self-developed loading device, and the sensitivity of influent factors on the rock-arch failure was analyzed by numerical test based on the particle flow code (PFC). The results showed that sandstone plate instability presented four phases: small deformation elastic stage, brittle fracture arching stage, ...

  11. A secondary analysis to determine variations of dental arch measurements with age and gender among Ugandans

    Okori, Hilda; Apolot, Pricilla S.; Mwaka, Erisa; Tumusiime, Gerald; Buwembo, William; Munabi, Ian G.


    Background Dental arch dimensions are useful in dental practice and in forensic odontology. Local data is essential because ethnic differences exist in dental arch dimensions. In the Ugandan population no studies had been done on dental arch dimensions. The objective of the current study was to determine the variations in dental arch dimensions with age and gender in a sample of dental casts from the Ugandan population. Method This was a secondary analysis of dental casts previously prepared ...

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

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


    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

  13. Measuring medial longitudinal arch deformation during gait. A reliability study

    Bencke, Jesper; Christiansen, Ditte; Jensen, Anne Kathrine Bendrup; Okholm, Anne; Sonne-Holm, Stig; Bandholm, Thomas


    Clinical evaluation of medial longitudinal arch deformation (MLAD) during walking gait is often estimated from static measures of e.g. navicular drop (ND) measured during quiet standing. The aim of the present study was to test the reliability of a new three-dimensional method of measuring the MLAD...

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

    Mahnken, Andreas H., E-mail: [University Hospital Giessen and Marburg, Philipps University of Marburg, Department of Diagnostic Radiology (Germany); Hoffman, Andras; Autschbach, Ruediger; Damberg, Anneke L. M., E-mail: [University Hospital RWTH Aachen, Department of Thoracic, Cardiac and Vascular Surgery (Germany)


    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.

  15. Double aortic arches, esophageal atresia and tracheal compression

    Majid Yameen; Warade Monali; Aziz Zarina; Karthik G


    We report a case of double aortic arch in a 12-month-old male infant well delineated on 64 slice computed tomography scan. It formed a complete vascular ring around the trachea compressing it. The symptoms resolved after surgical division of the ring.

  16. Visualization of soil arching in flexible piled embankments

    Tuğba Eskışar


    Piled embankments rely on soil arching, but, when geogrid reinforcements are used, membrane action within the reinforcement contributes to load distribution. The arching of soil in unreinforced and reinforced piled embankments is evaluated in this study. A small-scale test apparatus is used to model the settlement up to 5 mm in an embankment with four pile elements. Visual inspection of the soil settlement and soil-reinforcement interaction is important to explain the mechanism of arching. In this study, X-ray Computed Tomography (CT) method was used as a non-destructive technique. The arching of soil between the piles was observed in the case of rigid piles and in the case of flexible piles with grid type of reinforcement. The load carrying capacity increased up to 33% in the case of geogrid reinforcement, and the differential settlement decreased around 35%, proving the efficiency of piled embankments with geogrid reinforcements. It is also shown that, using X-ray CT method and visualization techniques provides a better understanding of soil behavior in a reinforced embankment with the flexible pile foundation system.

  17. Ennis Franciscan Friary, tomb niche under tower, jamb and arch

    O'Donovan, Danielle


    Sketch of jamb and arch, moulding comprises from intrados out: hollow chamfer, hollow chamfer, hollow chamfer, right-angled rebate, hollow chamfer, hollow chamfer. One of a number of Flamboyant tombs found on or west of the Shannon. The Ennis example is closest in design to that in the north chancel wall at Athenry Dominican Friary.

  18. Portumna Dominican Friary, west door, jamb, arch and hood

    O'Donovan, Danielle


    West door jamb, arch and hood. Moulding from intrados comprises: hollow, fillet, roll-and-fillet, fillet, hollow. The hood, which is placed far from the jamb, comprises from outer to inner face: frontal fillet, hollow, right-angled rebate, hollow.

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

    Andreas Habertheuer


    Full Text Available 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.

  20. 3D Stretchable Arch Ribbon Array Fabricated via Grayscale Lithography

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


    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.

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

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


    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.


    Subhankar Chakraborty


    Full Text Available The functional importance of hand is revealed by its rich vascularity contributed by superficial and deep palmar arches (SPA and DPA.Superficial palmar arch is located superficial to flexor tendons, and deep palmar arch deep to lumbrical muscles. Variations are found more often in SPA than DPA, later being more or less constant. During routine undergraduate dissection, we observed, unilateral incomplete SPA being formed by superficial palmar branches of ulnar and radial artery in the right hand of a male cadaver. These two arteries remained independent without anastomosis forming incomplete arch (SPA.The superficial branch of ulnar artery entered hand superficial to flexor retinaculum and supplied middle, ring and little finger by three branches. The superficial branch of radial artery via its two branches supplied index finger and thumb. Classical SPA formation was seen on left side. The presence of an incomplete SPA as in this case is a potential danger in RA harvesting for CABG.Variations in SPA play a pivotal role in microvascular surgical procedures of hand, RAinterventions and arterial graft applications.

  3. Integrated System of Structural Health Monitoring and Intelligent Management for a Cable-Stayed Bridge

    Bin Chen


    Full Text Available It is essential to construct structural health monitoring systems for large important bridges. Zhijiang Bridge is a cable-stayed bridge that was built recently over the Hangzhou Qiantang River (the largest river in Zhejiang Province. The length of Zhijiang Bridge is 478 m, which comprises an arched twin-tower space and a twin-cable plane structure. As an example, the present study describes the integrated system of structural health monitoring and intelligent management for Zhijiang Bridge, which comprises an information acquisition system, data management system, evaluation and decision-making system, and application service system. The monitoring components include the working environment of the bridge and various factors that affect bridge safety, such as the stress and strain of the main bridge structure, vibration, cable force, temperature, and wind speed. In addition, the integrated system includes a forecasting and decision-making module for real-time online evaluation, which provides warnings and makes decisions based on the monitoring information. From this, the monitoring information, evaluation results, maintenance decisions, and warning information can be input simultaneously into the bridge monitoring center and traffic emergency center to share the monitoring data, thereby facilitating evaluations and decision making using the system.


    EIGBEONAN Andrew B.


    Full Text Available The aim of this paper is to search and find methods of fostering creativity or ideas relating to creativity in teaching the arch-design studio. Teaching creativity through its methods will be making the students grounded in designing with creativity ideas and therefore we can have professionals that design and build with satisfaction, safety and complementary. It means we can have real buildings and places that satisfy our clients, the society and in harmony with the environment. Although there are similarities in the curricula of training architects all over the world, but educators go about it in their own convenient and suitable ways and styles. The ideas of creativity have been part of architecture from the onset, but are not deligently applied and also not formally incorporated in the curricula of training. The topic is also very relevant and timely as arch-educators and other stakeholders are of the opinion that something has to be done to improve the ways and methods of training architects, especially the teaching of the arch-design studio with regards to creativity. Through exploration of literature and interviews (physical and telephone call this paper finds methods of stimulating creativity ideas in the teaching of arch-design studio. Some of the methods of motivating creativity found in teaching the arch-design studio are: analogy, metaphors, biomimicry, brainstorming, attribute listing, mental map, TRIZ, restrictions, charrette, browsing, excursions, focus groups, other peoples viewpoints, using crazy ideas, using experts, visualizing a goal, working with dreams and images and giving students design tools such as drawings CAD and model making.

  5. Arch of opportunity : Peace country operators expand, undeterred by vandalism

    Jaremko, D.


    Activity levels in the Peace River Arch (Para) area of northwest Alberta are continuing despite reports of oilfield vandalism. Devon Energy is continuing its development of the 2 trillion cubic feet of original gas in place in the Dunevegan field and is also planning activities in the Triassic halfway formation in the southwest Arch. At depths between 2500 and 2800 metres, initial gas-flow rates from sour wells range from 2 to 5 million cubic feet per day. Devon is also targeting medium gravity oil in the northwest arch, and light gravity oil in the eastern part of the PRA. EnCana is expected to exit 2005 with production of 350 MMcf of gas equivalent per day from the PRA after having drilled more than 200 wells. A number of juniors are also expressing interest in the area. Galleon Energy has increased its focus in the PRA to 9000 barrels of oil equivalent per day and has separated its strategy into 4 areas: multi-zone drilling; a tight gas resource play; light, sweet crude development; and deep exploration in the arch's southwest corner. Talisman Energy has 4 rigs working in the area and plans to spend $168 million in the Grande Prairie area, with plans to drill 85 wells. Details of the Peace Arch Operators Group were provided, who meet with regulatory bodies like the Alberta Energy and Utilities Board (EUB), Alberta Environment, regional governments and the RCMP. A rash of oilfield sabotage in the late 1990s led to notoriety for the area. In October 2005, more sabotage occurred near a drilling rig. Satellite connected, web-interface cameras were installed by Anadarko, the rig's owner. Most people in the area are in favour of development, since oil and gas activity in the area will lead to economic benefits for the region. 3 figs.

  6. Three-dimensional stiffness of the carpal arch.

    Gabra, Joseph N; Li, Zong-Ming


    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


    Ibragimov, I. A.


    Problem statement. The forms of Christian and Islamic arches are compared in the context of re-ligious essence of Christianity and Islam. The form of arch is considered from two positions. The first position is the character of the form of the arch; the second position is the character of dynamic vector of the arch in visual perception.Results and conclusions. The character of the form of the arch is considered for the first time in the context of orientation of man in religious and notional ...

  8. Correlation between arch form and facial form: A cross sectional study

    Sanjna Nayar


    Full Text Available Arch form is a key determinant in teeth position. Teeth selection and placement must be based on the functional and esthetic needs of the patient. Keeping in mind, the biomechanics involved with the prosthesis. The aim of the study was to evaluate the correlation between arch form and facial form. About 40 individuals in the age group of 20-25 years were involved in the study. The arch form and facial form were analyzed statistically to check for any correlation. It was found that, 63.63% of leptoprosophic individuals had squarish arch form while, 54.6% of mesoprosophic faces had ovoid arch form.

  9. Idea of Design Scheme of Oujiang Bridge in Wenzhou City%温州瓯江大桥设计方案构思

    罗嗣碧; 唐方清; 孔祥升; 杨华振


    Based on city bridge landscape requirements, a basket-type arch bridge scheme and a self anchored suspension bridge are presented for Oujiang Bridge. The two schemes are good fusion bridge located in natural environment. The basket type arch bridge scheme and the self-anchored suspension bridge scheme are in the top three on the bridge design competition at the same time. The projects and its landscape effect are introduced to provide the references for the same types of bridge landscape design.%基于城市桥梁的景观要求,对瓯江大桥提出了提篮式拱桥方案和自锚式悬索桥方案,两种方案均能很好地融合桥位处的自然环境.提篮式拱桥方案和高低塔自锚式悬索桥方案同时进入本桥方案竞赛的前三名.介绍了此方案的构思及其景观效果,为同类型的桥梁景观设计提供借鉴及参考.

  10. Generalized Gaussian Bridges

    Sottinen, Tommi


    A generalized bridge is the law of a stochastic process that is conditioned on linear functionals of its path. We consider two types of representations of such bridges: orthogonal and canonical. In the canonical representation the filtrations and the linear spaces generated by the bridge process and the original process coincide. In the orthogonal representation the bridge is constructed from the entire path of the underlying process. The orthogonal representation is given for any continuous Gaussian process but the canonical representation is given only for so-called prediction-invertible Gaussian processes. Finally, we apply the canonical bridge representation to insider trading by interpreting the bridge from an initial enlargement of filtration point of view.

  11. Concrete bridge prioritization system

    Kesselring, Debbie Anne


    An alternative method of prioritization for concrete bridge maintenance, repair, and rehabilitation activities is required due to the inability of the current system to manage the increasing nmnber of aging concrete bridges. The Concrete Bridge Prioritization System was proposed because of its ability to address the critical technical parameters of safety and cost benefit in prioritization of funding and work allocation. The analysis includes four parts, service life assessment, s...

  12. Dental arch form in three Pacific populations: a comparison with Japanese and Australian aboriginal samples.

    Kasai, K; Kanazawa, E; Aboshi, H; Richards, L C; Matsuno, M


    The purpose of this study was to provide information about arch shape variations among South Pacific populations. The application of Fourier transforms, Y(phi i) = ao/2 + sigma (aicos phi i + bisin phi i) was used to separate two components of variation; size and shape. Dental arch size can be described by one coefficient (ao), while the shape can be summarized by the first three harmonics (amp1-3) in the Fourier series. The materials used in this study were dental casts of South Pacific populations (Fiji, Western Samoa and Kiribati), Australian Aboriginals and Japanese. Fijians, Western Samoans and Kiribati people have larger upper and lower dental arches than that of Japanese. These populations were separated by the arch size and first Fourier amplitudes which showed the arch depth/width ratio. The Fijian upper and lower dental arches were significantly larger than those found in other populations and was characterized by a wide posterior arch breadth. The Western Samoan and Kiribati arch shape was more similar to the Japanese arch shape than the Fijian. Distribution patterns of arch shape characteristics in these populations showed the same tendencies in the upper and lower arches. PMID:9476433

  13. Cine magnetic resonance imaging study of blood flow and wall motion of the aortic arch

    The aortic arch has 3D distortions in the transverse arch in the axial view, and we previously reported that this distortion is a risk factor in the pathogenesis of arch aneurysms. In this study, we evaluated blood flow and movement of the aortic arch. In 10 healthy young volunteers, ECG-gated cine magnetic resonance imaging was carried out in the axial plane of the transverse arch, the coronal plane of the ascending arch, and the long axial plane along the entire arch. Left anterolateral movements around the midpoint of the transverse arch in the systolic phase were observed in all of the men (6.3±1.59 mm) and women (4.8±0.73 mm). A jet flow was detected in the systolic phase along the right side of the aortic wall. At the top of the plane, this jet flow turned to the left in a clockwise rotation in the anterior view. In the long axial plane, a turbulent flow in the systolic phase was observed distal to the left subclavian arterial orifice in 6 of the 7 cases. In conclusion, this turbulent flow and left anterolateral wall motion of the transverse arch are due to anatomical three-dimensional distortion of the transverse arch. We propose that these phenomena may be important risk factors in the pathogenesis of arch aneurysms. (author)

  14. Bridging the Gap

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska;

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures.......Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures....

  15. Bridging the Gap

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska; Murdock, Karen; Schmidt, Iben Julie


    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures. Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ve...

  16. Approche archéo-anthropologique des inhumations militaires

    Rigeade, Catherine


    Le fait militaire occupe une place importante au sein des études historiques car il permet d’entrevoir les rapports entre l’armée et la société. Les conflits armés sont très largement abordés en archéologie par l’étude des systèmes défensifs ou par la découverte d’objets de parures ou de pièces d’armes. En revanche, on ne dénombre que peu d’ensembles funéraires mis en place à la suite d’un conflit ou d’évènements guerriers ayant fait l’objet d’une fouille archéologique ou d’une étude anthropo...

  17. Post Flare Giant Arches and Run-Away Reconnection

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


    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.


    EIGBEONAN, Andrew B.


    The aim of this paper is to search and find methods of fostering creativity or ideas relating to creativity in teaching the arch-design studio. Teaching creativity through its methods will be making the students grounded in designing with creativity ideas and therefore we can have professionals that design and build with satisfaction, safety and complementary. It means we can have real buildings and places that satisfy our clients, the society and in harmony with the environment. Although the...

  19. Quasi-MLE for quadratic ARCH model with long memory

    Grublytė, Ieva; Surgailis, Donatas; Škarnulis, Andrius


    We discuss parametric quasi-maximum likelihood estimation for quadratic ARCH process with long memory introduced in Doukhan et al. (2015) and Grublyt\\.e and \\v{S}karnulis (2015) with conditional variance given by a strictly positive quadratic form of observable stationary sequence. We prove consistency and asymptotic normality of the corresponding QMLE estimates, including the estimate of long memory parameter $0< d < 1/2$. A simulation study of empirical MSE is included.

  20. Behaviour of Frictional Joints in Steel Arch Yielding Supports

    Horyl, P.; Šňupárek, Richard; Maršálek, P.


    Roč. 59, č. 3 (2014), s. 723-734. ISSN 0860-7001 R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk ED1.1.00/02.0070 Grant ostatní: GA MŠk(CZ) MSM6198910027 Institutional support: RVO:68145535 Keywords : steel arch yielding support * frictional joints * bolt connection * slip support * fem Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 0.608, year: 2013

  1. Perinatal outcomes and anomalies associated with fetal right aortic arch

    Ahmet Gül


    Full Text Available Objective: To evaluate the prenatal findings, associated anomalies, and prognosis of right aortic arch (RAA anomalies. Material and Methods: All cases referred for detailed ultrasonography and fetal echocardiography between October 2006 and July 2009 were systematically examined for aortic arch anomalies and associated cardiac and extracardiac anomalies. Prenatal findings of all cases with aortic arch anomalies and intracardiac and extracardiac findings were prospectively registered in an electronic database that included fetal echocardiography. Outcomes of the cases were collected postnatally from the patients’ obstetricians, neonatal unit archieves, and pediatric cardiologists. Results: We detected 12 cases of RAA (0.37%; n=12/3200. Mean gestational age at diagnosis was 24 weeks (range, 21–33 weeks. Of the 12 cases of RAA, five (41.7% had a major cardiac defect, including tetralogy of Fallot (n= 3, atrioventricular septal defect (n=1, and ventricular septal defect (n=1. An extracardiac anomaly was observed in three cases (25%. The fetal karyotype was trisomy 21 in one case with increased nuchal translucency (6.6 mm. Microdeletion 22q11 analyses performed in three cases were normal. The postnatal courses of the cases with isolated RAA were uneventful. Two cases associated with major cardiac and extracardiac anomalies were lost in the early neonatal period. The case of trisomy 21 was terminated. The other four cases of RAA with an associated cardiac anomaly are currently in follow up. Conclusion: Aortic arch anomalies, particularly RAA, can be diagnosed by fetal echocardiography. The prognosis for isolated RAA is relatively good compared with that for RAA with associated anomalies.


    Ştefan Cristian CIUCU


    Full Text Available In this study, after a brief literature review, the RON / EURO exchange rate time series over the 03.01.2005 - 05.02.2015 time period is analyzed. After checking the stationarity of the data - ARCH, GARCH, EGARCH and TARCH models will be developed and compared. Next the best model is chosen and the serial correlation and the Jarque-Bera test are further analyzed with various conclusions being drawn.

  3. A Review of Diseases of Aortic Arch: Diagnosis by CTA

    S. Sabouri


    The noninvasive revolution in cardiovascular imaging has altered the diagnostic algorithm for all types of acquired and congenital cardiovascular disease. CT techniques are commonly used in the diagnosis of aortic arch and its major branch vessels as well as thoracic and abdominal aortic diseases. CT angiogra-phy combines with CT scans obtained detailed in-formation on precise morphology and extent of dis-ease. Studies were performed on an MDCT unit (4row GE light speed). In infants and small...

  4. Giant aortic arch aneurysm complicating Kawasaki′s disease

    Kaouthar Hakim; Rafik Boussada; Lilia Chaker; Fatma Ouarda


    Kawasaki disease (KD) is a common acute vasculitis in pediatric population that usually involves small- and middle-sized arteries, commonly coronary arteries. Although the incidence and natural course of coronary aneurysms after KD are well documented in studies, related reports on peripheral arterial and aortic aneurysms are scarce. We report the occurrence of a giant aortic aneurysm involving the horizontal part of aortic arch in a 28-month-old boy diagnosed with KD. This complication was m...

  5. The Randomized Shortened Dental Arch Study: Tooth Loss

    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.


    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 ...

  6. Principles of Bridge Reliability

    Thoft-Christensen, Palle; Nowak, Andrzej S.

    The paper gives a brief introduction to the basic principles of structural reliability theory and its application to bridge engineering. Fundamental concepts like failure probability and reliability index are introduced. Ultimate as well as serviceability limit states for bridges are formulated...

  7. The floating water bridge

    When high voltage is applied to distilled water filled in two glass beakers which are in contact, a stable water connection forms spontaneously, giving the impression of a floating water bridge. A detailed experimental analysis reveals static and dynamic structures as well as heat and mass transfer through this bridge

  8. Modelling autogenous expansion for magnesia concrete in arch dams

    Feng JIN; Guoxin ZHANG; Xiaoqing LUO; Chuhan ZHANG


    Magnesia Concrete is a kind of expansive con-crete used in Chinese hydraulic engineering more and more widely. To evaluate the effects of autogenous expan-sion on the stresses of arch dams, a simple model of auto-genous expansion for Magnesia Concrete in dam engineering is presented. This model is based on three assumptions: 1) the total amount of autogenous expan-sion of Magnesia Concrete is related only to the properties of materials and mixing of concrete; 2) the autogenous expansion of Magnesia Concrete is irreversible due to the irreversibility of hydration reaction of Magnesia in the concrete; 3) the autogenous expansion strain rates of Magnesia Concrete bear a relation between temperature and residual Magnesia per unit volume of concrete. The model is verified by some experimental data of autogen-ous expansion of Magnesia Concrete and field-measured data of an arch dam in China. Embedded into finite ele-ment arch dam simulation software, this model is employed to simulate the effects of autogenous expansion of Magnesia Concrete in hydraulic engineering.

  9. Wheel arch aerodynamics of a modern road vehicle

    A geometrically faithful model of the Aston Martin V12 Vanquish was formed in 3D CAD and used to perform an extensive CFD study into the airflow in and around the wheel arch of the vehicle. Parameters such as spin ratio, ground clearance, vertical and horizontal insertion into the wheel arch and the yaw angles experienced during cornering, were all under investigation. The additional aim of the research was to validate or refute the use of CFD as a tool in this complex area of fluid flow. This research serves to highlight a number of problems and potential solutions in the use of CFD. Meshing problems can be eliminated with increased computational power and suggestions have been made to improve the modeling of rotating boundaries that include radial features such as wheel spokes. Much of the CFD data ties well with previously conducted experimental work, if not numerically then in trend. Without additional physical validation however, it is difficult to ascertain the overall accuracy and usefulness of the remaining results, which have not yet been conducted in physical reality. Despite its limitations, the use of CFD permitted an extensive analysis in a comparatively short length of time and served to highlight potential areas for increased scrutiny. As an example, results from the final yaw angle case drew attention to a potential concern for aerodynamic destabilisation of the vehicle during cornering, generating lift on the front arch of the car that is already lifted due to cornering forces and body roll. (author)

  10. C-arm guided closed reduction of zygomatic arch fracture

    The zygomatic arch is structurally protruded and is easily fractured. The classic management of zygomatic arch fracture has been mentioned the Keen, Lothrop, Dingman and Alling and threaded K-wire. All of the above methods have advantages and disadvantages. To minimize the disadvantages, we performed threaded K-wire for the first time using C-arm image intensifier. The subjects were 16 patients with Knight North group II (Zygomatic arch fracture). Among them the C-arm was used in 12 patients and the operator used sensitivity general method in 4 patients and confirmed the operation by mobile X-ray equipment. In conclusion, both groups were satisfied surgically and cosmetically. Using the C-arm, actual image at the time operation was clear and satisfied, the surrounding tissue damage was minimized and at was more accurately completed. The operation time was shortened by 30 to 60 minutes proving it to be an efficient method. We suggest though that further studies be needed to evaluate the radiation effect on these patients

  11. First and second branchial arch syndromes: multimodality approach

    First and second branchial arch syndromes (BAS) manifest as combined tissue deficiencies and hypoplasias of the face, external ear, middle ear and maxillary and mandibular arches. They represent the second most common craniofacial malformation after cleft lip and palate. Extended knowledge of the embryology and anatomy of each branchial arch derivative is mandatory for the diagnosis and grading of different BAS lesions and in the follow-up of postoperative patients. In recent years, many new complex surgical approaches and procedures have been designed by maxillofacial surgeons to treat extensive maxillary, mandibular and external and internal ear deformations. The purpose of this review is to evaluate the role of different imaging modalities (orthopantomogram (OPG), lateral and posteroanterior cephalometric radiographs, CT and MRI) in the diagnosis of a wide spectrum of first and second BAS, including hemifacial microsomia, mandibulofacial dysostosis, branchio-oto-renal syndrome, Pierre Robin sequence and Nager acrofacial dysostosis. Additionally, we aim to emphasize the importance of the systematic use of a multimodality imaging approach to facilitate the precise grading of these syndromes, as well as the preoperative planning of different reconstructive surgical procedures and their follow-up during treatment. (orig.)


    Liliana-Gabriela HALIŢCHI


    Full Text Available The present study analyzes the orthodontic nickel-titanium alloy with orthodontic shape memory (Niti GAC arches, Nitinol 3M arches, Beta Titanium 3M arches from the viewpoint of its cytotoxicity. Apart from the intrinsic toxicity of the metals upon cells, corrosion may dramatically alter the behaviour of alloys, as evidenced by the in vitro and in vivo studies developed in the field. Due to the high and variable nickel content, its is possible that, at least theoretically, the released ions should produce – as a result of intraoral corrosion – secondary effects, which makes necessary to assert the cytotoxicity of NiTi alloys prior to their safe utilizationor in the oral cavity of children and young patients. Evaluation of cell morphology and determination of cell viability, following exposure to the 3 types of orthodontic materials, evidenced no toxic reactions. Several problems are still to be elucidated, related to the consequences of the surface conditions, of the dissolution and in vivo release of the nickel ions after a longer treatment, of the accumulations of ion traces, of the response of the dental-periodontal tissues, of the effects manifested at cell and molecular level. Apart from the intrisic toxicity of metals upon cells, corrosion may dramatically influence the behaviour of alloys under in vitro conditions, comparatively with the in vivo ones, the nitinol samples being biologically safe.

  13. First and second branchial arch syndromes: multimodality approach

    Senggen, Elodie; Laswed, Tarek; Meuwly, Jean-Yves; Maestre, Leonor Alamo; Meuli, Reto; Gudinchet, Francois [University Hospital of Lausanne, Radiology Department, Lausanne (Switzerland); Jaques, Bertrand [University Hospital of Lausanne, Department of Otorhinolaryngology, Lausanne (Switzerland)


    First and second branchial arch syndromes (BAS) manifest as combined tissue deficiencies and hypoplasias of the face, external ear, middle ear and maxillary and mandibular arches. They represent the second most common craniofacial malformation after cleft lip and palate. Extended knowledge of the embryology and anatomy of each branchial arch derivative is mandatory for the diagnosis and grading of different BAS lesions and in the follow-up of postoperative patients. In recent years, many new complex surgical approaches and procedures have been designed by maxillofacial surgeons to treat extensive maxillary, mandibular and external and internal ear deformations. The purpose of this review is to evaluate the role of different imaging modalities (orthopantomogram (OPG), lateral and posteroanterior cephalometric radiographs, CT and MRI) in the diagnosis of a wide spectrum of first and second BAS, including hemifacial microsomia, mandibulofacial dysostosis, branchio-oto-renal syndrome, Pierre Robin sequence and Nager acrofacial dysostosis. Additionally, we aim to emphasize the importance of the systematic use of a multimodality imaging approach to facilitate the precise grading of these syndromes, as well as the preoperative planning of different reconstructive surgical procedures and their follow-up during treatment. (orig.)

  14. Mechanics Evolution Characteristics Analysis of Pressure-arch in Fully-mechanized Mining Field

    S.R. Wang


    Full Text Available Based on a practical engineering, the three-dimension computational model was built using FLAC3D under the fullymechanized mining condition. Considering four variation factors, such as the distance of mining advancing, the strength of the surrounding rock, the speed of mining advancing and the dip angle of the coal seam, the mechanics evolution characteristics of the pressure-arch were analyzed. The result showed that for the horizontal seam, the geometric shape of the pressure-arch varied from flat arch to round arch gradually and the height and thickness of the pressure-arch also increased; the maximum principal stress in the skewback also increased with the working face advancing. With the strength of the surrounding rock from soft to hard, the arch thickness reduced, and the arch loading decreased. To improve the mining speed can do some contributions to the stability of the pressure-arch in the mining field. With the increase of dip angle of the seam, the pressure-arch displayed an asymmetric shape, the vault was tilted and moved to the upward direction. At the same time, the thickness of the pressure-arch increased, and the stress concentration in the skewback tended to be further intensified.


    Venkateswara Rao


    Full Text Available INTRODUCTION: Knowledge of the frequency of anatomical variations of arterial pattern of hand is crucial for safe and successful hand surgical approach, diagnostic and therapeutic procedures. The superficial pal mar arch is a major blood supply to the hand. Various ano malous patterns in the superficial arch of hand are reported. The superficial pal mar arch is formed predominantly by ulnar artery with a contribution from superficial branch of radial artery. OBSERVATIONS: Superficial palmar arch is dissected within the p alm and observed from its origin to termination. Variations in its origin, branches were observed. A classic superficial palmar arch was found in 10% [5/50]. O ut of dissected specimens complete arch found in 67% and incomplete arch was 33%. Incomplete arch is formed by ulnar artery alone. It supply four and half fingers and give five branches. Majority of arches is supplied by three and half fingers and gives four branches. DISCUSSION: Many attempts have been made to classify these variations. A complex cla ssification of superficial pal mar arch by Coleman & Anson [1961]. S ince then, many other classification have been suggested by different authors [Karlsson & N iechajev, 1982; al - Turk & Metcalf, 1984; Doscher et al. 1985; Ruengsakulrachh et al. 2001;] provi des simplest understanding of distribution of the arches. Although the classical pattern of the arch occurs in frequently, anatomical presence of a complete superficial palmar arch varies from 84% to 66% [Coleman & Anson]. This incidence was lower in the c urrent study and might be a reflection of sample size [52 hands]. The median artery was found in 10% of the hands, similar frequency to that reported by McCormack et al. [1953].

  16. The Layout and Simulation of Logarithmic Spiral Double Curved Arch Dam Transverse Joints%The Layout and Simulation of Logarithmic Spiral Double Curved Arch Dam Transverse Joints

    DU Ting-na; DU Qi-lu; HUI Yuan


    Because of its good condition with mechanics, logarithmic spiral double curve arch bam has been widely used in the practical engineering. The introduction of a new method in how to divide transverse joint in arch dam will be given and the further research of its calculation has been done. The C++ is used in electronic procedure and the 3D simulation has been finished with AutoCAD, which will provide the object model for computer simulation of the arch dam and the division of finite element mesh. Meanwhile, this method in dividing the transverse joint in arch dam also can be taken as the calculated basis for the design and calculation of arch dam, construction lofting and the calculation of the work amount.

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

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


    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 ( 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: 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

  18. Bridge technology report


    Please note this is a Short Discount publication. As LANs have proliferated, new technologies and system concepts have come to the fore. One of the key issues is how to interconnect networks. One means of interconnection is to use a 'bridge'. Other competing technologies are repeaters, routers, and gateways. Bridges permit traffic isolation, connect network segments together and operate at the MAC layer. Further, because they operate at the MAC layer, they can handle a variety of protocols such as TCP/IP, SNA, and X.25. This report focuses on the specific technology of bridging two netw

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

    Sachdeva, Shabina; Tripathi, Arvind; Kapoor, Pranav


    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

  20. Gender identification and morphologic classification of tooth, arch and palatal forms in Saudi population

    Mohammad, Aljanakh; Koralakunte, Pavankumar Ravi


    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 ...

  1. Initial arch wires for alignment of crooked teeth with fixed orthodontic braces.

    Wang, Yan


    The initial arch wire is the first arch wire to be inserted into the fixed appliance at the beginning of orthodontic treatment and is used mainly for correcting crowding and rotations of teeth. With a number of orthodontic arch wires available for initial tooth alignment, it is important to understand which wire is most efficient, as well as which wires cause the least amount of root resorption and pain during the initial aligning stage of treatment.

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

    Amm, E W; Bou-Serhal, J P


    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. Bridge Management Systems:present and future

    Thoft-Christensen, Palle


    In this paper bridge management systems are discussed with special emphasis on management systems for reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way.

  4. The evolution of arch filament systems and moving magnetic features around a sunspot

    Ma, Li; Zhou, Wangping; Zhou, Guiping; Zhang, Jun


    Context. Arch filament systems (AFSs) are usually considered as the chromospheric manifestations of the emerging flux regions (EFRs) seen in Hα observations. Moving magnetic features (MMFs) look similar to EFRs in magnetograms, but often appear in the decaying phase of an active region (AR) and behave differently from EFRs. A possible relation between AFS and MMF would be important for revealing a common mechanism for building up basic structures on the Sun. Aims: Based on Hα and magnetic field observations with high spatial resolution, we study the evolution of MMFs around a sunspot, as well as their related AFSs from birth to death. Methods: The multiwavelength observations from the New Vacuum Solar Telescope (NVST) and the Solar Dynamic Observatories (SDO) are co-aligned in the spatial and the temporal sense. MMFs appeared near the northern end of a light bridge (LB). Their related AFSs were carefully identified and traced from their appearance to disappearance based on Hα, EUV data, and magnetograms. Results: In the main sunspot of AR NOAA 11711 during April 1-4, 2013, many slow-speed MMFs with a polarity opposite to that of the sunspot appeared from the close vicinity of the northern end of a LB. Different from other smaller MMFs around the sunspot, these MMFs were always related to arch filaments and eventually formed AFSs with three twisting branches. The total flux involved in the AFSs was estimated to be about 2.7 × 1021 Mx. The largest MMF "M1" evolved into a small pore that led to an intensity reduction in the continuum intensity images. The appearance and evolution of the AFSs near the sunspot seems to be controlled by MMFs emanating from the penumbra. Owing to continual magnetic cancellation between the MMFs and their surrounding opposite flux, the AFSs gradually disintegrated and finally disappeared. Conclusions: The appearance and evolution of the AFSs near the sunspot seem to be controlled by these MMFs emanating from the penumbra. Movies are

  5. Bridging a cultural gap

    Leviatan, Talma


    There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes—aimed at bridging the gap between high-school mathematics and tertiary mathematics—is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a potential bridging programme, this paper aims at demonstrating that the gap can be bridged, by presenting an ongoing modular bridging programme especially designed for the diverse types of student populations in teachers training colleges. We also present here some innovative teaching and assessment methods that were judged essential for the success of these programmes—focusing mainly on the "Questionnaire Based Instruction Method". Finally we suggest directions of follow up and research.

  6. Bridged Race Population Estimates

    U.S. Department of Health & Human Services — Population estimates from "bridging" the 31 race categories used in Census 2000, as specified in the 1997 Office of Management and Budget (OMB) race and ethnicity...

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

    Dholakia, Kartik D; Bhat, Shweta R


    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

  8. Ennis Franciscan Friary, eastern tomb niche, north nave wall, jamb and arch moulding

    O'Donovan, Danielle


    Jamb and arch of tomb niche. From intrados moulding comprises: ogee, quadrant. Similar tomb niches can be found at Quin, Adare Franciscan, Adare Augustinian, Askeaton, Lislaughtin, Abbeydorney, Kilconnell.

  9. Congenital aortic arch anomalies: diagnosis using contrast enhanced magnetic resonance angiography

    ZHU Ming; ZHONG Yu-min; LI Yu-hua; SUN Ai-min; JIN Biao


    @@ Congenital aortic arch anomalies occur most commonly in children. The disease can be classified into three types: ① obstructive congenital abnormalities, including coarctation of aorta (CoA) and interruption of aortic arch (IAA); ② non-obstructive congenital abnormalities, including double aortic arch and others; ③ congenital shunt abnormalities, including different types of patent ductus arteriosus (PDA). Management of patients with congenital aortic arch anomalies relies on imaging. Routine imaging modalities, such as conventional X-ray plain film and transthoracic echocardiography (TTE), have been recently complemented by magnetic resonance imaging (MRI).


    Khin Myo Thu; Than Winn; Jayasinghe, J.A.P.; Nizam Abdullah


    A cross-sectional study was conducted to compare maxillary arch and head measurements between ethnic Malays and Chinese. Mean ages were 23.5 years (Malay) and 21.1 years (Chinese), and both groups were brachycephalic with the cephalic index 86.4 for Malay and 85.9 for Chinese which is not significantly different between them. Means of anterior arch width (AAW), posterior-arch-width (PAW) and arch-length were significantly different between two groups. AAW and PAW were significantly different ...

  11. Earthquake safety assessment of concrete arch and gravity dams

    Lin Gao; Hu Zhiqiang


    Based on research studies currently being carried out at Dalian University of Technology, some important aspects for the earthquake safety assessment of concrete dams are reviewed and discussed. First, the rate-dependent behavior of concrete subjected to earthquake loading is examined, emphasizing the properties of concrete under cyclic and biaxial loading conditions. Second, a modified four-parameter Hsieh-Ting-Chen viscoplastic consistency model is developed to simulate the rate-dependent behavior of concrete. The earthquake response of a 278m high arch dam is analyzed, and the results show that the strain-rate effects become noticeable in the inelastic range. Third, a more accurate non-smooth Newton algorithm for the solution of three-dimensional frictional contact problems is developed to study the joint opening effects of arch dams during strong earthquakes. Such effects on two nearly 300m high arch dams have been studied. It was found that the canyon shape has great influence on the magnitude and distribution of the joint opening along the dam axis. Fourth, the scaled boundary finite element method presented by Song and Wolf is employed to study the dam-reservoir-foundation interaction effects of concrete dams. Particular emphases were placed on the variation of foundation stiffness and the anisotropic behavior of the foundation material on the dynamic response of concrete dams. Finally, nonlinear modeling of concrete to study the damage evolution of concrete dams during strong earthquakes is discussed. An elastic-damage mechanics approach for damage prediction of concrete gravity dams is described as an example. These findings are helpful in understanding the dynamic behavior of concrete dams and promoting the improvement of seismic safety assessment methods.

  12. Metallicity in the Galactic Center: The Arches cluster

    Najarro, Francisco; Figer, Donald F.; Hillier, D. John; Kudritzki, Rolf P.


    We present a quantitative spectral analysis of five very massive stars in the Arches cluster, located near the Galactic center, to determine stellar parameters, stellar wind properties and, most importantly, metallicity content. The analysis uses a new technique, presented here for the first time, and uses line-blanketed NLTE wind/atmosphere models fit to high-resolution near-infrared spectra of late-type nitrogen-rich Wolf-Rayet stars and OfI+ stars in the cluster. It relies on the fact that...

  13. Two ARCH Models and Their Limitations as Diffusion Processes

    杨海波; 叶俊


    Two typical ARCH models: the ASDARCH model and the APARCH model are analyzed. Let Yk and σ2k denote the log returns and the volatility. When the time interval h goes to zero, (Yk,σ2k), as a discrete time Markov chain system, weakly converges to a continuous time diffusion process. The continuous time approximation of the ASDARCH model is done using two different methods. With some transformation, these two results are equivalent to high frequency data. The continuous time approximation of the APARCH model is obtained by a different procedure.

  14. On monolithic stability and reinforcement analysis of high arch dams

    YANG; Qiang; CHEN; YingRu; LIU; YaoRu


    Monolithic stability safety and reinforcement based on monolithic stability are very important for arch dam design.In this paper,the issue is addressed based on deformation reinforcement theory.In this approach,plastic complementary energy norm can be taken as safety Index for monolithic stability.According to deformation reinforcement theory,the areas where unbalanced force exists require reinforcement,and the required reinforcement forces are just the unbalanced forces with opposite direction.Results show that areas with unbalanced force mainly concentrate in dam-toes,dam-heels and faults.

  15. Vibration monitoring of long bridges and their expansion joints and seismic devices

    Islami Kleidi


    Full Text Available This paper presents a number of recently installed Structural Health Monitoring (SHM systems: a on a 2km double suspension bridge; b on a long railway viaduct that has experienced cracking; and c on a steel arch bridge in a seismically active area. Damage detection techniques have been applied based on high-frequency measurements of vibrations, pressure and strain, enabling a proper understanding of the structures’ behaviour to be gained. The diverse range of applications presented, designed in collaboration with structure owners and design engineers, includes damage detection on expansion joints of suspension bridges, crack analysis and correlation with accelerations of high-speed trains, and high-frequency performance monitoring of seismic devices. These case studies, based on both static and dynamic approaches, demonstrate the usefulness and ease of use of such systems, and the enormous gains in efficiency they offer.

  16. Construction and Design of Post-Tensioned Pearl-Chain Bridges using SL-Technology

    Halding, Philip Skov


    a filling layer of lower stiffness above the arches to level the road surface. The present Ph.D. thesis is part of a larger development project about Pearl‐Chain Bridges funded by Innovationsfonden. The project also included another Ph.D. study about the developed materials used in Pearl‐Chain Bridges......, and numerical modelling. Despite of high levels of normal force in PC‐Bridges, the result showed that a Mesnager inspired hinge type had a response similar to what was predicted in the literature. A specially designed saddle bearing also had elastic and plastic rotational resistance, but this hinge type......) A test to fracture to observe the ductility in the system, and fracture type. The collapse occurred after two plastic hinges were formed in the 3/8, and 5/8 points of the span. Several warnings signs were observed when approaching the maximum loading....

  17. Integral Abutment and Jointless Bridges

    Cristian-Claudiu Comisu


    Integral bridges, or integral abutment and jointless bridges, as they are more commonly known in the USA, are constructed without any movement joints between spans or between spans and abutments. Typically these bridges have stub-type abutments supported on piles and continuous bridge deck from one embankment to the other. Foundations are usually designed to be small and flexible to facilitate horizontal movement or rocking of the support. Integrally bridges are simple or multiple span ones t...

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

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


    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

  19. Design for Huaxi Bridge in Highway around Guiyang City%贵阳环城高速公路花溪大桥设计



    Huaxi Bridge is a super large bridge across above Huaxi reservoir in the south line of Guiyang City Highway. The main bridge, which is a 192 m half-through concrete-filled steel tube arch bridge with 29.3 m in full width ( bi-direction four lanes plus sidewalks) and 100 km/h design speed, is the key bridge and controlling project of the whole line. The author illustrates the general design situation of the bridge, including bridge-type selection, design parameters, structure details and construction methods. According to the situations at the bridge site, Huaxi Bridge is the first bridge using the technologies such as triangular space truss arch, cutting caisson foundation, self-compacting concrete-filled steel tube in Guizhou region, which can give some references for the same type of bridge constructions in mountainous karst area.%花溪大桥为贵阳环城高速公路南环线跨越花溪水库的一座特大型桥梁,主桥为192 m的中承式钢管混凝土拱桥,大桥全宽29.3 m(双向四车道+人行道),设计速度100 km/h,是全线重点桥梁和控制性工程.介绍该桥的总体设计情况,包括桥式选择、设计参数、构造细节、施工方法.根据桥址处的条件大桥在贵州地区首次采用了三角形空间桁架拱、挖井基础、自密实钢管混凝土等技术,对多山岩溶地区同类型桥梁建设具有参考意义.

  20. Building problem solving environments with the arches framework

    Debardeleben, Nathan [Los Alamos National Laboratory; Sass, Ron [U NORTH CAROLINA; Stanzione, Jr., Daniel [ASU; Ligon, Ill, Walter [CLEMSON UNIV


    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.

  1. archAR: an archaeological augmented reality experience

    Wiley, Bridgette; Schulze, Jürgen P.


    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.

  2. Design and construction of prestressed arch using plastic shoppers waste

    Ali Khan, S.


    Full Text Available Since the development of plastic in the last century, being versitile it has become very popular for diversified uses. The problem appears when these plastics, particularly shoppers are disposed as waste. The current reuse and recycling rates for the plastic shoppers waste are very low. Construction Industry has a great potential for the reuse of shoppers waste. Shoppers waste has been compressed to fabricate compressed shoppers waste (CSW blocks. This study is related to an innovative reuse of CSW-blocks for the construction of prestressed structural arch. This paper is dedicated to the design and construction of structural arch using shoppers waste as a material.

    Desde su desarrollo durante el siglo pasado y debido a su versatilidad, el plástico se ha hecho ubicuo en la sociedad actual. Los problemas surgen cuando este material, sobre todo cuando conforma bienes de consumo, se desecha. Actualmente, los índices de valorización y reciclado de residuos plásticos de origen doméstico son muy bajos. El sector de la construcción tiene una enorme potencial para reutilizar este tipo de residuos, que se pueden comprimir para fabricar bloques. Este artículo presenta un uso innovador de los bloques de residuos plásticos: la construcción de un arco estructural pretesado. Describe el proyecto y la ejecución de un arco estructural construido con estos materiales de desecho.


    Most stars form in a cluster environment. These stars are initially surrounded by disks from which potentially planetary systems form. Of all cluster environments, starburst clusters are probably the most hostile for planetary systems in our Galaxy. The intense stellar radiation and extreme density favor rapid destruction of circumstellar disks via photoevaporation and stellar encounters. Evolving a virialized model of the Arches cluster in the Galactic tidal field, we investigate the effect of stellar encounters on circumstellar disks in a prototypical starburst cluster. Despite its proximity to the deep gravitational potential of the Galactic center, only a moderate fraction of members escapes to form an extended pair of tidal tails. Our simulations show that encounters destroy one-third of the circumstellar disks in the cluster core within the first 2.5 Myr of evolution, preferentially affecting the least and most massive stars. A small fraction of these events causes rapid ejection and the formation of a weaker second pair of tidal tails that is overpopulated by disk-poor stars. Two predictions arise from our study. (1) If not destroyed by photoevaporation protoplanetary disks of massive late B- and early O-type stars represent the most likely hosts of planet formation in starburst clusters. (2) Multi-epoch K- and L-band photometry of the Arches cluster would provide the kinematically selected membership sample required to detect the additional pair of disk-poor tidal tails.

  4. Behaviour of Steel Arch Stabilized by a Textile Membrane

    Svoboda, O.; Machacek, J.


    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.

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

    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.


    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.

  6. Micron narrowband adaptive optics imaging in the arches cluster

    Blum, R D; Pasquali, A; Heydari-Malayeri, M; Conti, P S; Schmutz, W


    Canada-France-Hawaii-Telescope adaptive optics bonnette images through narrow-band filters in the $K-$band are presented for the Arches cluster. Continuum fluxes, line fluxes, and equivalent widths are derived from high angular resolution images, some near diffraction limited, for the well known massive stars in the Arches cluster. Images were obtained in the lines of \\ion{He}{1} 2.06 \\mic, \\ion{H}{1} Br$\\gamma$ (2.17 \\mic), and \\ion{He}{2} 2.19 \\mic as well as continuum positions at 2.03 \\mic, 2.14 \\mic, and 2.26 \\mic. In addition, fluxes are presented for \\ion{H}{1} P$\\alpha$ (1.87 \\mic) and a nearby continuum position (1.90 \\mic) from Hubble Space Telescope archival data. The 2 \\mic and P$\\alpha$ data reveal two new emission-line stars and three fainter candidate emission-line objects. Indications for a spectral change of one object between earlier observations in 1992/1993 and our data from 1999 are found. The ratio of \\ion{He}{2} 2.19 \\mic to Br$\\gamma$ emission exhibits a narrow distribution among the s...

  7. Right aortic arch: a report of two cases

    A right aortic arch (RAA) is a rare congenital abnormality not always clinically manifested. The most common symptoms include dysphagia, dyspnoea on exertion, stridor, and bronchitis, resulting from a vascular ring around the trachea or esophagus. Asymptomatic cases may be viewed in adulthood. The report presents two cases of RAA found coincidentally in adult patients diagnosed using conventional chest X- ray and computed tomography (CT). Case 1 presents an abnormal course of the aortic arch, first manifested as dyspnoea in adulthood. Case 2 presents RAA with the right subclavian artery as a separate branch associated with an abnormal course of the left subclavian artery. Asymptomatic esophageal compression was also found. The abnormality was accompanied by numerous atherosclerotic lesions in peripheral vessels. Abnormal blood flow conditions might have contributed to a faster progression of atherosclerosis. RAA may remain asymptomatic for the entire life. Symptoms are caused by compression of the surrounding structures or impaired blood flow. RAA may be associated with malformations of its branches. (author)

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

    Tripathi, S.; Gekelman, W. N.


    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

  9. Rock-Arch Instability Characteristics of the Sandstone Plate under Different Loading Conditions

    Shuren Wang


    Full Text Available Under the concentrated loading and the uniform loading, the tests on the brittle fracture and the hinged arching until the rock-arch instability of the sandstone plate were conducted using self-developed loading device, and the sensitivity of influent factors on the rock-arch failure was analyzed by numerical test based on the particle flow code (PFC. The results showed that sandstone plate instability presented four phases: small deformation elastic stage, brittle fracture arching stage, rock-arch bearing stage, and rock-arch instability stage. Under the uniform loading, the maximum vertical force of the rock-arch instability was much higher than that under the concentrated loading condition, but the maximum lateral force was almost the same. The number of acoustic emission (AE and its positioning results of the sandstone plate showed that the extent of the plate damage under the uniform loading was higher than that under the concentrated loading condition. The friction coefficient effect, size effect, loading rate effect, and the initial horizontal force effect on the rock-arch instability were analyzed by the PFC3D numerical experiment.


    I. A. Ibragimov


    Full Text Available Problem statement. The forms of Christian and Islamic arches are compared in the context of re-ligious essence of Christianity and Islam. The form of arch is considered from two positions. The first position is the character of the form of the arch; the second position is the character of dynamic vector of the arch in visual perception.Results and conclusions. The character of the form of the arch is considered for the first time in the context of orientation of man in religious and notional space. It is established that in Islam, vertical vector is not principal, despite the vertical vector common to Christian and Islam arches. The reason is that in Christian temple, the prayer is “orientated” upwards, to God, whereas in Islam there is only one principal, global reference point, the Kaaba, that is, the orientation of the prayer in Islam is horizontal vector. Owing to this, Islamic arch tends to upwards, but reference point of the system of spiritual coordinates of Islam artificially “blunts” and redirects the arch in its direction