Sample records for pylons

  1. Failure Analysis of a Helicopter External Fuel-Tank Pylon (United States)

    Newman, John A.; Piascik, Robert S.; Lindenberg, Richard A.


    An eight-inch-long (0.2 m) crack was found in an external fuel-tank pylon of a U.S. Coast Guard HH-60 helicopter. The damaged pylon was removed from service and destructively examined at NASA Langley Research Center (LaRC) to determine the cause of the crack. Results of the analysis revealed that crack initiation occurred at corrosion pits in a fastener hole and crack propagation was a result of cyclic loading.

  2. Pylon fractures of the ankle: A distinct clinical and radiological entity

    International Nuclear Information System (INIS)

    Mainwaring, B.L.; Daffner, R.H.; Riemer, B.L.


    Pylon fractures are a distinct clinical and radiological entity that should not be confused with trimalleolar fractures. Radiographic and clinical comparison of 20 cases of each fracture type revealed definite distinguishing features. First, pylon fractures inevitably were associated with profound comminution of the distal tibia. The trimalleolar injury was associated with fractures of the medial, lateral, and posterior malleoli without comminution. Second, in contrast to timalleolar fractures, pylon fractures had intraarticular extension of at least one tibial fracture through the dome of the plafond. Third, 60% of all pylon fractures were associated with a fractured talus; the talus was intact in all trimalleolar fractures. Fourth, the distal tibiofibular syndesmosis was constant in the pylon fractures but was separated in all trimalleolar fractures

  3. Scale model test on a novel 400 kV double-circuit composite pylon

    DEFF Research Database (Denmark)

    Wang, Qian; Bak, Claus Leth; Silva, Filipe Miguel Faria da

    This paper investigates lightning shielding performance of a novel 400 kV double-circuit composite pylon, with the method of scale model test. Lightning strikes to overhead lines were simulated by long-gap discharges between a high voltage electrode with an impulse voltage and equivalent conductors...... around the pylon is discussed. Combined test results and striking distance equation in electro-geometric model, the approximate maximum lightning current that can lead to shielding failure is calculated. Test results verify that the unusual negative shielding angle of - 60° in the composite pylon meets...... requirement and the shielding wires provide acceptable protection from lightning strikes....

  4. A Model-Driven Approach for 3D Modeling of Pylon from Airborne LiDAR Data

    Directory of Open Access Journals (Sweden)

    Qingquan Li


    Full Text Available Reconstructing three-dimensional model of the pylon from LiDAR (Light Detection And Ranging point clouds automatically is one of the key techniques for facilities management GIS system of high-voltage nationwide transmission smart grid. This paper presents a model-driven three-dimensional pylon modeling (MD3DM method using airborne LiDAR data. We start with constructing a parametric model of pylon, based on its actual structure and the characteristics of point clouds data. In this model, a pylon is divided into three parts: pylon legs, pylon body and pylon head. The modeling approach mainly consists of four steps. Firstly, point clouds of individual pylon are detected and segmented from massive high-voltage transmission corridor point clouds automatically. Secondly, an individual pylon is divided into three relatively simple parts in order to reconstruct different parts with different strategies. Its position and direction are extracted by contour analysis of the pylon body in this stage. Thirdly, the geometric features of the pylon head are extracted, from which the head type is derived with a SVM (Support Vector Machine classifier. After that, the head is constructed by seeking corresponding model from pre-build model library. Finally, the body is modeled by fitting the point cloud to planes. Experiment results on several point clouds data sets from China Southern high-voltage nationwide transmission grid from Yunnan Province to Guangdong Province show that the proposed approach can achieve the goal of automatic three-dimensional modeling of the pylon effectively.

  5. Assessment of Lightning Shielding Performance of a 400 kV Double-Circuit Fully Composite Pylon

    DEFF Research Database (Denmark)

    Jahangirl, Tohid; Bak, Claus Leth; Silva, Filipe Miguel Faria da


    of diagonal and differs from other widely used configurations in overhead transmission lines i.e. horizontal, delta and vertical configurations. On the other hand, unlike traditional steel lattice towers, the pylon removes access to ground potential due to its non-conductive materials and therefore......, the lightning shielding of pylon requires a ground potential access to shield wires which can be achieved by utilizing ground cable inside the hollow cross-arm and pylon body. However, efficient assigning of lightning shielding system for the fully composite pylon is one of the major challenges...

  6. A Stochastic Geometry Method for Pylon Reconstruction from Airborne LiDAR Data

    Directory of Open Access Journals (Sweden)

    Bo Guo


    Full Text Available Object detection and reconstruction from remotely sensed data are active research topic in photogrammetric and remote sensing communities. Power engineering device monitoring by detecting key objects is important for power safety. In this paper, we introduce a novel method for the reconstruction of self-supporting pylons widely used in high voltage power-line systems from airborne LiDAR data. Our work constructs pylons from a library of 3D parametric models, which are represented using polyhedrons based on stochastic geometry. Firstly, laser points of pylons are extracted from the dataset using an automatic classification method. An energy function made up of two terms is then defined: the first term measures the adequacy of the objects with respect to the data, and the second term has the ability to favor or penalize certain configurations based on prior knowledge. Finally, estimation is undertaken by minimizing the energy using simulated annealing. We use a Markov Chain Monte Carlo sampler, leading to an optimal configuration of objects. Two main contributions of this paper are: (1 building a framework for automatic pylon reconstruction; and (2 efficient global optimization. The pylons can be precisely reconstructed through energy optimization. Experiments producing convincing results validated the proposed method using a dataset of complex structure.

  7. Damping properties of non-conductive composite materials for applications in power transmission pylons

    DEFF Research Database (Denmark)

    Kliem, Mathias; Rüppel, Marvin; Høgsberg, Jan


    This study aims to characterize the fibre direction dependent damping properties of non-conductive composite materialsto be used in newly designed electrical power transm°ission pylons, on which the conducting cables will be directlyconnected. Thus, the composite structure can be designed both to...

  8. Assessment of Lightning Shielding Performance of a 400 kV Double-Circuit Fully Composite Transmission Line Pylon

    DEFF Research Database (Denmark)

    Jahangiri, Tohid; Bak, Claus Leth; Silva, Filipe Miguel Faria da


    -quality insulation sections. Thus, the configuration of phase conductors on the cross-arm is in the form of diagonal and differs from other widely used configurations in overhead transmission lines i.e. horizontal, delta and vertical configurations. Unlike traditional steel lattice towers, the composite pylon does...... not provide access to ground potential due to its non-conductive materials. Therefore, the lightning shielding of pylon and conductors requires a ground potential access to shield wires by utilizing a ground cable inside the hollow cross-arm and pylon body. Efficient design of a lightning shielding system...

  9. Investigations on the Influence of the In-Stream Pylon and Strut on the Performance of a Scramjet Combustor

    Directory of Open Access Journals (Sweden)

    Hao Ouyang


    Full Text Available The influence of the in-stream pylon and strut on the performance of scramjet combustor was experimentally and numerically investigated. The experiments were conducted with a direct-connect supersonic model combustor equipped with multiple cavities. The entrance parameter of combustor corresponds to scramjet flight Mach number 4.0 with a total temperature of 947 K. The research results show that, compared with the scramjet combustor without pylon and strut, the wall pressure and the thrust of the scramjet increase due to the improvement of mixing and combustion effect due to the pylon and strut. The total pressure loss caused by the strut is considerable whereas pylon influence is slight.

  10. The measurement of thoron (220Rn) concentration in indoor air continuously using pylon model WLx

    International Nuclear Information System (INIS)

    Hasnel Sofyan


    The concentration of thoron ( 220 Rn) in particular location can be higher than radon ( 220 Rn), however, its presence is always neglected. This might be due to the difficulties in calibration and discrimination between radon and thoron. From biokinetic and dosimetric model, it has been known that the dominant contribution of thoron to the effective dose is in the lungs. UNSCEAR estimates the doses contribution of thoron and its progenies is between 5-10% of the annual dose received by the general public and the risk level is 4.4 times greater than radon and progenies. Therefore, it is necessary to study the thoron concentration in indoor air and workplaces. Radon-thoron concentration in indoor air can be determined by direct methods using Pylon Model WLx device and passive methods using Solid State Nuclear Track Detector (SSNTDs). In this research the measurement of thoron was carried out continuously using Pylon Model WLx equipment that is sensitive to radon for 24, 65, 72, 116 and 154 hours in different rooms. The measurement result showed that the mean value of thoron working level (WL) concentration obtained in room-1 was 2.53 ± 0.67 Bq/m 3 with maximum and minimum of thoron concentrations were 3.37 and 2.22 Bq/m 3 respectively. From the measurement in different locations, it was obtained that the largest and smallest average concentrations of thoron progenies were 0.83 ± 0.23 Bq/m 3 and 0.29 ± 0.64 Bq/m 3 , while the maximum and minimum concentration values were 7.80 Bq/m 3 and 0.01 Bq/m 3 respectively. Pylon Model WLx device is not enables to be used for longer and large scale survey area concurrently, so the SSNTDs which is sensitive to the emission of alpha particles and can measure cumulative thoron concentrations is required. (author)

  11. Nonlinear Stability Analysis of a Composite Girder Cable-Stayed Bridge with Three Pylons during Construction

    Directory of Open Access Journals (Sweden)

    Xiaoguang Deng


    Full Text Available Based on the nonlinear stability analysis method, the 3D nonlinear finite element model of a composite girder cable-stayed bridge with three pylons is established to research the effect of factors including geometric nonlinearity, material nonlinearity, static wind load, and unbalanced construction load on the structural stability during construction. Besides, the structural nonlinear stability in different construction schemes and the determination of temporary pier position are also studied. The nonlinear stability safety factors are calculated to demonstrate the rationality and safety of construction schemes. The results show that the nonlinear stability safety factors of this bridge during construction meet the design requirement and the minimum value occurs in the maximum double cantilever stage. Besides, the nonlinear stability of the structure in the side of edge-pylon meets the design requirement in the two construction schemes. Furthermore, the temporary pier can improve the structure stability, effectively, and the actual position is reasonable. In addition, the local buckling of steel girder occurs earlier than overall instability under load in some cable tension stages. Finally, static wind load and the unbalanced construction load should be considered in the stability analysis for the adverse impact.

  12. A State of the Art Review- Methods to Evaluate Electrical Performance of Composite Cross-arms and Composite-based Pylons

    DEFF Research Database (Denmark)

    Wang, Qian; Bak, Claus Leth; Silva, Filipe Miguel Faria da


    A novel uni-body composite pylon has been proposed for 400 kV transmission lines with advantages of compacted size, friendly looking and cost competitiveness. As its configuration is quite different from the traditional lattice pylon, its electrical performance needs in-depth investigation...... and evaluation, for which electrical testing methods are essential. However, as research on composite-based pylons is still in initial stage, leaving international standards and theoretical analysis on this topic very limited, effective testing methods to evaluate the fully composite pylon’s electrical...... performance need to be studied. This paper sums up experience and key advances on testing methods to evaluate electrical performance of composite cross-arms and composite-based pylons. Based on state of the art review, several feasible testing methods that can be used to verify the feasibility of the novel...

  13. An Experimental Study into Pylon, Wing, and Flap Installation Effects on Jet Noise Generated by Commercial Aircraft (United States)

    Perrino, Michael

    A pylon bottom bifurcation and a wing with variable flaps were designed and built to attach to a scaled model of a coaxial exhaust nozzle system. The presence of the pylon bifurcation, wing, and flaps modify the characteristics of the exhaust flow forc- ing asymmetric flow and acoustics. A parametric study was carried out for assessing and relating the flow field characteristics to the near-field pressure and far-field acous- tic spectra. The flow field was investigated experimentally using both stream-wise and cross-stream PIV techniques where the near-field pressure and far-field acoustic spectra were measured using microphone arrays. Contour mapping of the flow field characteristics (e.g. mean velocity and turbulence kinetic energy levels) and near-field acoustics with and without installation effects were used to explain the changes in the far-field acoustics.

  14. Aerodynamic analysis for aircraft with nacelles, pylons, and winglets at transonic speeds (United States)

    Boppe, Charles W.


    A computational method has been developed to provide an analysis for complex realistic aircraft configurations at transonic speeds. Wing-fuselage configurations with various combinations of pods, pylons, nacelles, and winglets can be analyzed along with simpler shapes such as airfoils, isolated wings, and isolated bodies. The flexibility required for the treatment of such diverse geometries is obtained by using a multiple nested grid approach in the finite-difference relaxation scheme. Aircraft components (and their grid systems) can be added or removed as required. As a result, the computational method can be used in the same manner as a wind tunnel to study high-speed aerodynamic interference effects. The multiple grid approach also provides high boundary point density/cost ratio. High resolution pressure distributions can be obtained. Computed results are correlated with wind tunnel and flight data using four different transport configurations. Experimental/computational component interference effects are included for cases where data are available. The computer code used for these comparisons is described in the appendices.

  15. Ostosintesis of low profile in the treatment of the fractures of the tibial pylon

    International Nuclear Information System (INIS)

    Agudelo R, Juan Fernando; Kalb H, Juan Pedro


    The preliminary results are presented, among January 1999 - September 2000, in the General Hospital of Medellin - Clinica Leon XIII. Eight cases were revised of patient with intraarticular fractures of the tibial pylon, treaties with open reduction and osteosintesis of low profile following the modified protocol of Ruedi-Allgower, with the objective of describing the quality of the reduction and the postoperative complications. The data were obtained of the clinical history and personal interview with the patients. The time of pursuit average was of 5,2 months. Of the eight fractures, seven (87.5%) they were consequence of accidents of traffic and one for firearm projectile. Two fractures were presented type I (25%), three type II (37.5%) and three type III (37.5%), according to the classification of Ruedi-Allgower. The surgery was carries out on the average to the 13.4 days. In all the cases it uses traction transcalcanea intraoperative; six patients required osteosintesis of the fibula: The plaques of low profile in tibia were modeled to the anterolateral surface to diminish the medial desperiostization. In six cases the quality of the radiological reduction was good according to the approaches of Burwell and Charnley in one to regulate and in one bad. In all the cases it begins passive and active rehabilitation after the first week and the support was restricted by three months. In two cases superficial dehiscence of the surgical wound those were presented, which they evolved satisfactorily, and a case of asintomatic no union has not required reintervention. The results suggest that the osteosintesis of low profile is a sure method of treatment of these lesions if it is carried out when the conditions of soft tissues are good and the medial desperiostization is limited


    Directory of Open Access Journals (Sweden)

    V. V. Khominets


    Full Text Available Objective — to develop and implement improved approaches to the diagnosis and tactics of surgical treatment in patients with fractures of the distal tibia metaepiphysis.Material and methods. The study included 126 patients with fractures of distal tibia metaepiphysis of «B» and «C» types who underwent internal fixation with plates in 2005–2012. The authors analyzed surgical treatment outcomes within the period from 2.5 to 9 years (average of 5.7–2.3 years of postoperative follow up. Average age of patients was 23.4±2.1 years. Patients were divided into the main group (64 patients and the comparison group (62 patients. In the comparison group, traditional approaches to diagnosis and surgical treatment were used, including standard clinical examination and X-rays of the affected ankle in two views and the median access to the distal tibia metaepiphysis. In the main group, a specially elaborated algorithm for selection of optimal surgical tactics was utilized basing on the improved diagnostics program. Clinical and functional data were assessed by Foot and Ankle Outcome Score (FAOS and SF-36 Health Survey. Roentgenological assessment was done by X-rays and CT scans. Statistical significance of the differences was evaluated by Wald-Wolfowitz and Fisher tests.Results. Improved approaches to the tactics of surgical treatment in patients with pylon fractures of «B» and «C» types allowed to reduce the incidence of unsatisfactory anatomical and functional outcomes from 43.5% to 28.1%. The number of satisfactory and good outcomes increased by 4.7% and 10.7% respectively after application of improved therapeutic and diagnostic approaches.Conclusion. Proposed improved approaches to verification of severe intraarticular fractures of the distal tibia metabiphysis allowed to increase the informative value of the diagnostic procedures and to avoid discrepancies between preand intraoperative assessment of fracture type by classifications of M

  17. The Influence of No-Primer Adhesives and Anchor Pylons Bracket Bases on Shear Bond Strength of Orthodontic Brackets

    Directory of Open Access Journals (Sweden)

    Andrea Scribante


    Full Text Available Objective. The aim of this study was to compare the shear bond strength (SBS and adhesive remnant index (ARI scores of no-primer adhesives tested with two different bracket bases. Materials and Methods. 120 bovine permanent mandibular incisors were divided into 6 groups of 20 specimens. Two brackets (ODP with different bracket bases (anchor pylons and 80-gauge mesh were bonded to the teeth using a conventional adhesive (Transbond XT and two different no-primer adhesive (Ortho Cem; Heliosit systems. Groups were tested using an instron universal testing machine. SBS values were recorded. ARI scores were measured. SEM microphotographs were taken to evaluate the pattern of bracket bases. Statistical analysis was performed. ANOVA and Tukey tests were carried out for SBS values, whereas a chi-squared test was applied for ARI scores. Results. Highest bond strength values were reported with Transbond XT (with both pad designs, Ortho Cem bonded on anchor pylons and Heliosit on 80-gauge mesh. A higher frequency of ARI score of “3” was reported for Transbond XT groups. Other groups showed a higher frequency of ARI score “2” and “1.” Conclusion. Transbond XT showed the highest shear bond strength values with both pad designs.

  18. Characterization of clay-modified thermoset polymers under various environmental conditions for the use in high-voltage power pylons

    DEFF Research Database (Denmark)

    Kliem, Mathias; Høgsberg, Jan Becker; Wang, Qian


    The effect of nanoclay on various material properties like damping and strength of typical thermoset polymers, such as epoxy and vinyl ester, was investigated. Different environmental conditions typical for high-voltage transmission pylons made of composite materials were taken into account. Resin...... samples were prepared with various clay weight fractions ranging from 0% to 3%. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and rheological analysis were used to study the morphology and the structure of the nanocomposites. For all nanoclay-modified thermoset polymers......, the morphology was found to be of exfoliated structure mainly. Static, uniaxial tensile tests showed that the addition of nanoclay to thermoset polymers led to a beneficial effect on the stiffness, whereas the tensile strength and ductility significantly decreased. When exposed to different environmental...

  19. Experimental and Computational Study of the Flow past a Simplified Geometry of an Engine/Pylon/Wing Installation at low velocity/moderate incidence flight conditions (United States)

    Bury, Yannick; Lucas, Matthieu; Bonnaud, Cyril; Joly, Laurent; ISAE Team; Airbus Team


    We study numerically and experimentally the vortices that develop past a model geometry of a wing equipped with pylon-mounted engine at low speed/moderate incidence flight conditions. For such configuration, the presence of the powerplant installation under the wing initiates a complex, unsteady vortical flow field at the nacelle/pylon/wing junctions. Its interaction with the upper wing boundary layer causes a drop of aircraft performances. In order to decipher the underlying physics, this study is initially conducted on a simplified geometry at a Reynolds number of 200000, based on the chord wing and on the freestream velocity. Two configurations of angle of attack and side-slip angle are investigated. This work relies on unsteady Reynolds Averaged Navier Stokes computations, oil flow visualizations and stereoscopic Particle Image Velocimetry measurements. The vortex dynamics thus produced is described in terms of vortex core position, intensity, size and turbulent intensity thanks to a vortex tracking approach. In addition, the analysis of the velocity flow fields obtained from PIV highlights the influence of the longitudinal vortex initiated at the pylon/wing junction on the separation process of the boundary layer near the upper wing leading-edge.

  20. Pylon Locations - USACE IENC (United States)

    Department of Homeland Security — These inland electronic Navigational charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  1. Pylon Areas - USACE IENC (United States)

    Department of Homeland Security — These inland electronic Navigational charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  2. How dangerous are mobile phones, transmission masts, and electricity pylons?


    Wood, A W


    Electrical power and mobile communications deliver enormous benefit to society, but there are concerns whether the electric and magnetic field (EMF) emissions associated with the delivery of this benefit are linked to cancer or other health hazards. This article reviews the strength of the available epidemiological and laboratory evidence and notes that this falls short of what is normally required to establish a causal link. However, because of scientific uncertainty a cautious approach is o...

  3. How dangerous are mobile phones, transmission masts, and electricity pylons? (United States)

    Wood, A W


    Electrical power and mobile communications deliver enormous benefit to society, but there are concerns whether the electric and magnetic field (EMF) emissions associated with the delivery of this benefit are linked to cancer or other health hazards. This article reviews the strength of the available epidemiological and laboratory evidence and notes that this falls short of what is normally required to establish a causal link. However, because of scientific uncertainty a cautious approach is often advocated, but here, too, there may be a tendency to judge these risks more harshly than those in other areas with similar strength of evidence.

  4. Big Pylons: Mixed signals for transmission. Spatial planning for energy distribution

    International Nuclear Information System (INIS)

    Ritchie, Heather; Hardy, Maelíosa; Lloyd, M. Greg; McGreal, Stanley


    The effective delivery of a sustainable energy future raises many challenges in relation to energy distribution where a new understanding of spatial planning is needed in relation to energy production, consumption and storage. Understanding the emergent low carbon energy economy in terms of its production, distribution and consumption characteristics has prompted a deliberate spatial planning interest. This paper examines issues relating to spatial planning, regulation, political legitimacy and accountability in the current and future systems for energy distribution. In particular it examines the Beauly Denny public inquiry in Scotland as a case study in terms of demonstrating the changing state–market–civil relations in an energy transition context with differentiated values and interests. The case study highlights implications for the regulation in the public interest of highly contested spaces, places and development schemes, together with a synopsis of government structure and change that is influencing the future of spatial planning and energy distribution in particular. - Highlights: • We examine links between spatial planning and regulation of energy distribution. • We examine the Beauly Denny public inquiry in Scotland. • We highlight challenges surrounding the development of a resilient energy system. • We highlight links between spatial planning and infrastructural development

  5. The Effect of Bracket Base Pylon Orientation on the Shear Bond Strength of the ODP ANCHOR-LOCK Bracket Pad (United States)


    in the dark) ( Bourke et al., 1992; McClean et al., 1994). Resin-modified glass ionomer cements that possess photochemical settling reactions also...primer/adhesive on the shear bond strength of orthodontic brackets. Am J Orthod Dentofacial Orthop 2001; 119(6):621-624. 61 Bourke AM, Walls AW

  6. World War II Memorial Learning Activities. (United States)

    Tennessee State Dept. of Education, Nashville.

    These learning activities can help students get the most out of a visit to the Tennessee World War II Memorial, a group of ten pylons located in Nashville (Tennessee). Each pylon contains informational text about the events of World War II. The ten pylons are listed as: (1) "Pylon E-1--Terror: America Enters the War against Fascism, June…

  7. Comparison of overhead line lightning performance based on two different tower geometries

    DEFF Research Database (Denmark)

    Ebdrup, Thomas; Olason, Daniel; Bak, Claus Leth


    of the substation and transmission line is of great importance as it is a part of the 400 kV backbone between Sweden, Norway, Germany and the offshore wind farms in Horns Rev, Denmark. The new Eagle pylon has been designed with the focus of minimizing the visual impacted of overhead lines. A detailed lightning...... performance analysis of the existing Donau and the new Eagle pylon is therefore important in order to assess the risk of failure. The lightning strike analysis is based on the number of strikes expected to terminate on the line and an investigation of how many of these there may be expected to cause...... better protected from direct stroke than the phase conductors on the Donau pylon. Furthermore with respect to a backflash, the Eagle has a better performance than the Donau pylon. It is therefore concluded that the Eagle has a better lightning performance than the Donau....

  8. Infrastructural urbanism that learns from place

    DEFF Research Database (Denmark)

    Carruth, Susan


    . Conventionally, energy ‘infrastructure’ denotes a physical system of pipes, cables, generators, plants, transformers, sockets, and pylons, however recent architectural research emerging within the loosely defined movement of Infrastructural Urbanism has reframed infrastructure as a symbiotic system of flows...

  9. Snail arboreality: the microdistribution of (Gastropoda ...

    African Journals Online (AJOL)

    G = the number or snails in grasses, % = percentage proportion of shruh snail s to the total number ot' snails in both habitats, ..... transmission pylons (P.F. Kasigwa personal observations). .... ation and k is any positive integer. References.

  10. Minimising mortality in endangered raptors due to power lines: the importance of spatial aggregation to optimize the application of mitigation measures. (United States)

    Guil, Francisco; Fernández-Olalla, Mariana; Moreno-Opo, Rubén; Mosqueda, Ignacio; Gómez, María Elena; Aranda, Antonio; Arredondo, Angel; Guzmán, José; Oria, Javier; González, Luis Mariano; Margalida, Antoni


    Electrocution by power lines is one of the main causes of non-natural mortality in birds of prey. In an area in central Spain, we surveyed 6304 pylons from 333 power lines to determine electrocution rates, environmental and design factors that may influence electrocution and the efficacy of mitigation measures used to minimise electrocution cases. A total of 952 electrocuted raptors, representing 14 different species, were observed. Electrocuted raptors were concentrated in certain areas and the environmental factors associated with increased electrocution events were: greater numbers of prey animals; greater vegetation cover; and shorter distance to roads. The structural elements associated with electrocutions were shorter strings of insulators, one or more phases over the crossarm, cross-shaped design and pylon function. Of the 952 carcasses found, 148 were eagles, including golden eagle (Aquila chrysaetos), Spanish imperial eagle (Aquila adalberti) and Bonelli's eagle (Aquila fasciata). Electrocuted eagles were clustered in smaller areas than other electrocuted raptors. The factors associated with increased eagle electrocution events were: pylons function, shorter strings of insulators, higher slopes surrounding the pylon, and more numerous potential prey animals. Pylons with increased string of insulators had lower raptor electrocution rates than unimproved pylons, although this technique was unsuccessful for eagles. Pylons with cable insulation showed higher electrocution rates than unimproved pylons, both for raptors and eagles, despite this is the most widely used and recommended mitigation measure in several countries. To optimize the application of mitigation measures, our results recommend the substitution of pin-type insulators to suspended ones and elongating the strings of insulators.

  11. Minimising mortality in endangered raptors due to power lines: the importance of spatial aggregation to optimize the application of mitigation measures.

    Directory of Open Access Journals (Sweden)

    Francisco Guil

    Full Text Available Electrocution by power lines is one of the main causes of non-natural mortality in birds of prey. In an area in central Spain, we surveyed 6304 pylons from 333 power lines to determine electrocution rates, environmental and design factors that may influence electrocution and the efficacy of mitigation measures used to minimise electrocution cases. A total of 952 electrocuted raptors, representing 14 different species, were observed. Electrocuted raptors were concentrated in certain areas and the environmental factors associated with increased electrocution events were: greater numbers of prey animals; greater vegetation cover; and shorter distance to roads. The structural elements associated with electrocutions were shorter strings of insulators, one or more phases over the crossarm, cross-shaped design and pylon function. Of the 952 carcasses found, 148 were eagles, including golden eagle (Aquila chrysaetos, Spanish imperial eagle (Aquila adalberti and Bonelli's eagle (Aquila fasciata. Electrocuted eagles were clustered in smaller areas than other electrocuted raptors. The factors associated with increased eagle electrocution events were: pylons function, shorter strings of insulators, higher slopes surrounding the pylon, and more numerous potential prey animals. Pylons with increased string of insulators had lower raptor electrocution rates than unimproved pylons, although this technique was unsuccessful for eagles. Pylons with cable insulation showed higher electrocution rates than unimproved pylons, both for raptors and eagles, despite this is the most widely used and recommended mitigation measure in several countries. To optimize the application of mitigation measures, our results recommend the substitution of pin-type insulators to suspended ones and elongating the strings of insulators.

  12. In-flight piv for cror flight test demonstration


    Pommier-Budinger, Valérie; Bury, Yannick; Michon, Guilhem; Napias, Gael


    Designing innovative solutions for future aircraft is one the concerns of aeronautical engineers. Among the studied technologies, Counter Rotating Open Rotor (CROR) propeller technologies are appearing as a promising, though highly challenging, alternative solution to Ultra High Bypass Ratio (UHBR) engines. Amongst these challenges, the interaction of the wake of the CROR engine pylon with the counter rotating blades, positioned downstream of the pylon (pusher configuration), are responsible ...

  13. Christian Menn's recent bridge designs - Reducing structural elements to the simplest solution


    Brühwiler, E.; Mahmoud, Khaled M.


    The conceptual designs by Christian Menn of four landmark bridges are presented: 1) a 350-m span cable-stayed bridge with jointless deck girder, 2) a cable-stayed bridge with a single “spindle-shaped” pylon, 3) a bridge with an arch reaching high above the deck (both carrying a horizontally curved deck girder), and 4) a cable stayed bridge with three pylons monolithically connected to the deck girder. All of the original bridge designs are driven by the aim to optimize the flow of force...

  14. Boxing clever

    Energy Technology Data Exchange (ETDEWEB)

    Stanbury, Kate


    The outages caused by storms bringing down trees on power transmission lines on Boxing Day 1998 in Scotland, Northern Ireland and Northern England forced ScottishPower to modify its pylon policy. The results of the analysis of pylons requiring work by the Rural Care Team at ScottishPower are summarised, and the identification of the problems caused by the Sitk spruce is reported. The selection of the relocation and clearance remediation option, the policy of replacing one tree with two, the approach to landowners, and the need to consider environmental concerns during the planning of networks are discussed. (UK)

  15. Electric stress computations for designing a novel unibody composite cross-arm using finite element method

    DEFF Research Database (Denmark)

    Jahangiri, Tohid; Wang, Qian; Bak, Claus Leth


    This paper deal with the electrical performance of a newly proposed fully composite pylon in Denmark, which has a unibody composite cross-arm at 420 kV highest system voltage level. Electric field consideration along the insulations of the novel unibody cross-arm is one of the most important...

  16. Avian mortality rates on a power line near Kampala, Uganda

    African Journals Online (AJOL)

    power line carried on tall metal pylons, and a smaller 33-kV line, with three conduc- tors supported on wooden poles, ... able literature on bird mortality associated with power lines (e.g. Lehman et al. 2005,. Jenkins et al. 2010, Edison .... the conductor wires would have been hard to see. Residents reported that other birds.

  17. Illustrative Experiments of the Erosion of Sand and Accompanying Theoretical Considerations (United States)

    Schneiderbauer, Simon


    Winds in desert regions form the well-known barchan dunes. Frequently, human settlements are threatened by the migration of these dunes. But why do these dunes move? And how is dune migration in deserts connected to scour development in the vicinity of pylons in river beds or to snow cornices in alpine regions? This paper introduces the topic of…

  18. 78 FR 46301 - Airworthiness Directives; BAE Systems (Operations) Limited Airplanes (United States)


    ... of a cracked pick- up bracket of the forward outboard pylon of the number 1 engine due to stress... invite you to send any written relevant data, views, or arguments about this proposed AD. Send your... 3 attachment bolt holes. Subsequent investigation revealed that the cause of cracking was stress...

  19. Electric Field and Potential Distribution in a 420 kV Novel Unibody Composite Cross-Arm

    DEFF Research Database (Denmark)

    Jahangiri, Tohid; Bak, Claus Leth; Silva, Filipe Miguel Faria da


    the hollow core uni-body cross-arm through which ground cable passes to connect the shield wires. Two different shed profiles are considered on the cross-arm and evaluated based on the guidelines of IEC 60815-3. The 2D geometry of pylon is modeled in ANSYS Finite Element Analysis package. The electric field...

  20. MF magnitude does not affect body condition, pro-oxidants and anti-oxidants in Eurasian kestrel (Falco tinnunculus) nestlings

    NARCIS (Netherlands)

    Costantini, David; Casagrande, Stefania; Dell'Omo, Giacomo

    Pylons of utility lines are commonly used by breeding birds as structures for supporting their nests. Nesting near power lines, however, exposes adult birds and their offspring to the electric and magnetic fields (EMFs) produced by the current. Therefore, we searched for possible relationships

  1. NASA AERONAUTICS: Impact of Technology Transfer Activities Is Uncertain (United States)


    agreement, enabled it to make several design changes to its newest commercial aircraft to improve its speed and aerodynamic performance. The changes...made included modifying the overall shape of winglets on the end of both wings and changing the location of fixtures (pylons) that attach the engines

  2. 75 FR 20516 - Special Conditions: Cirrus Design Corporation, Model SF50; Fire Extinguishing for Upper Aft... (United States)


    ... defined in Sec. 11.19, under Sec. 11.38 and they become part of the type certification basis under Sec. 21... requiring and defining engine compartment fire extinguishing systems already exist for part 23 commuter... structure or the fuselage. In essence the engine could burn off of the pylon and not adversely compromise...

  3. Congregations of wintering Egyptian Vultures Neophron ...

    African Journals Online (AJOL)

    Nearly half of the birds were adults and the majority roosted on bird-safe types of electric pylons. Most of the Egyptian Vultures were found below 500 m above sea level, in bare areas, open savannas or grasslands, and their abundance was negatively related to the amount of cover of bush vegetation. The distribution of ...

  4. Variations in enamel damage after debonding of two different bracket base designs: An in vitro study. (United States)

    Ahangar Atashi, Mohammad Hossein; Sadr Haghighi, Amir Hooman; Nastarin, Parastou; Ahangar Atashi, Sina


    Background. Bracket base design is a factor influencing shear bond strength. High shear bond strength leads to enamel crack formation during debonding. The aim of this study was to compare enamel damage variations, including the number and length of enamel cracks after debonding of two different base designs. Methods. Eighty-eight extracted human premolars were randomly divided into2 groups (n=44). The teeth in each group were bonded by two types of brackets with different base designs: 80-gauge mesh design versus anchor pylon design with pylons for adhesive retention. The number and length of enamel cracks before bonding and after debonding were evaluated under an optical stereomicroscope ×40 in both groups. Mann-Whitney U test was used to compare the number of cracks between the two groups. ANCOVA was used for comparison of crack lengths after and before debonding in each group and between the two groups. Results. There was a significant increase in enamel crack length and numbers in each group after debonding. There was no significant difference in enamel crack numbers after debonding between the two groups, whereas the length of enamel cracks was significantly greater in anchor pylon base design after debonding. Conclusion. Bracket bases with pylon design for adhesive retention caused more iatrogenic debonding damage to enamel surface.

  5. Noise Simulations of the High-Lift Common Research Model (United States)

    Lockard, David P.; Choudhari, Meelan M.; Vatsa, Veer N.; O'Connell, Matthew D.; Duda, Benjamin; Fares, Ehab


    The PowerFLOW(TradeMark) code has been used to perform numerical simulations of the high-lift version of the Common Research Model (HL-CRM) that will be used for experimental testing of airframe noise. Time-averaged surface pressure results from PowerFLOW(TradeMark) are found to be in reasonable agreement with those from steady-state computations using FUN3D. Surface pressure fluctuations are highest around the slat break and nacelle/pylon region, and synthetic array beamforming results also indicate that this region is the dominant noise source on the model. The gap between the slat and pylon on the HL-CRM is not realistic for modern aircraft, and most nacelles include a chine that is absent in the baseline model. To account for those effects, additional simulations were completed with a chine and with the slat extended into the pylon. The case with the chine was nearly identical to the baseline, and the slat extension resulted in higher surface pressure fluctuations but slightly reduced radiated noise. The full-span slat geometry without the nacelle/pylon was also simulated and found to be around 10 dB quieter than the baseline over almost the entire frequency range. The current simulations are still considered preliminary as changes in the radiated acoustics are still being observed with grid refinement, and additional simulations with finer grids are planned.

  6. EHV/HV Underground Cable Systems for Power Transmission

    DEFF Research Database (Denmark)

    Bak, Claus Leth

    of the transmission system must be re‐thought in order to accommodate the transmission needs for the future. New lines have to be constructed. Transmission lines are usually laid out as overhead lines, which are large structures, i.e. a 400 kV power pylon is 50 meters high. According to public opinion, such power...

  7. 75 FR 74663 - Airworthiness Directives; The Boeing Company Model 747-400 and -400D Series Airplanes (United States)


    ... proposed AD results from a report of a fuel leak from the drain line of the number two engine pylon. We are proposing this AD to detect and correct chafing of the main fuel feed tube and the alternating current motor-driven hydraulic pump wire bundle, which could lead to arcing from the exposed wire to the fuel feed tube...

  8. 76 FR 41673 - Airworthiness Directives; The Boeing Company Model 747-400 and -400D Series Airplanes (United States)


    ... the record, the fuel leaked from the main fuel feed tube and drained through the drain line. We agree... concurrent actions. This AD was prompted by a report of a fuel leak from the main fuel feed tube at the number two engine pylon. We are issuing this AD to detect and correct chafing of the main fuel feed tube...

  9. 77 FR 28328 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters (United States)


    ... Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Corporation (Sikorsky) Model S-92A helicopters, which requires inspecting the tail rotor (T/R) pylon for a... service information identified in this proposed AD, contact Sikorsky Aircraft Corporation, Attn: Manager...

  10. Physical processes important to airborne radioactivity in an enclosed environment: Progress report

    International Nuclear Information System (INIS)

    Schery, S.D.


    Work continues on assembling our automated two filter thoron/radon system. The mechanical components have been built and are being tested. The micro-computer control circuit has been designed. Both the Pylon thoron source and aerosol generator are being tested. 11 refs

  11. Long term monitoring of carbon composite strands in the Penobscot-Narrows bridge. (United States)


    The Penobscot-Narrows Bridge was constructed between May 2003 and December 2006. The bridge is a cable-stayed design with twin pylons and a 2,120-foot span. This cable-stayed bridge features a cradle stay system that : allows for each cable strand in...

  12. Dynamic Behaviour of Different Types of Cable-Stayed Bridges Due to Earthquake Loads

    Directory of Open Access Journals (Sweden)

    Alireza Mirza Goltabar Roshan


    Full Text Available Construction of large-scale structures has been considered as one of the human's main achievements.  With their suitable view and high economical aspects, High-strength steel cables have been developed for analysis and erection of cable-stayed bridges in light of high speed development in computer technology. This type of bridges, while providing different behavior due to cable flexibility, has been recognized as one of the most practical choices for mid to large span bridges. This paper studies the non-linear dynamic behavior of cable bridges and the effect of some parameters (such as cable arrangement and shape of pylon on them. For this purpose, CSI Bridge software with the direct integration method of dynamic analysis has been used and the behavior of structure under different earthquake components has been analyzed for various conditions of cable arrangements and pylon shapes. Results indicate that the most suitable behavior would be for cable bridges with H-shape pylons arranged in series and also with A-shape pylons in radial arrangement.

  13. Adaptive Capabilities of the Eastern Imperial Eagle in Power Lines Exploration for Nesting Purposes in the Republic of Tatarstan, Russia

    Directory of Open Access Journals (Sweden)

    Rinur H. Bekmansurov


    Full Text Available This report presents information on the eastern imperial eagle nesting on electricity pylons in the Republic of Tatarstan (area of 67836.2 km2 on the eastern part of East-European (Russian Plain, where the habitat of this species, marked in GIS (ArcView 3.2a, is 49 thousand km2. During the research in 2011–2015 5 nests were found on steel electricity pylons, which sustains 3.25% from the whole amount of nesting areas (n=154. Rather local disposition of all found cases of nests on electricity pylons in Eastern Zakamye (High Zavolzhye limited by one landscape subzone – typical and southern forest-steppe, and in only two landscape regions with adjacent borders – indicates some general conditions which caused the adaptation.  Distance between nests on power lines in the Republic of Tatarstan ranged from 21.5 to 49.9 km, averaging 29.5±13.64 km (n=5. As this territory lacks interspecific competition, the main reason of nesting on electricity pylons is probably the reduction of distance to forage resources in conditions of intraspecific competition in the densest nesting group. Adaptive capabilities of the Eastern Imperial Eagle are connected with their ability to occupy nests of other birds, high tolerance to human influence, and with the high density of the power lines and low density of long-boled forests. It’s reported that the imperial eagles’ adaptation to living in environment with dense power line network continues, which expresses in increase of the nesting on electricity pylons.

  14. Parametric Analyses of Dynamic Characteristic of the Cable-Stayed Pedestrian Bridge

    Directory of Open Access Journals (Sweden)

    Pańtak Marek


    Full Text Available The paper presents characteristics of the structural system and results of dynamic field tests and numerical parametric analyses of three-span, two-pylon, cable-stayed pedestrian bridge with steel-concrete composite deck and spans of 25.5 + 60.0 + 25.5 m. The footbridge is characterized by increased dynamic susceptibility of the elements of the suspension system observed during the everyday operation of the structure. The analyses have shown that the high amplitude vibrations of the pylon back-stay cables change the parameters of the structural system and consequently change the value of the natural vibration frequencies of the structure. In the paper, the selection methodology of parameters of the computational model which allows to correctly determine the natural vibration frequencies of the footbridge has been presented.

  15. High-voltage shared-service line in the Stuttgart area

    Energy Technology Data Exchange (ETDEWEB)

    Goerler, W; Benz, A [Technische Werke der Stadt Stuttgart A.G. (F.R. Germany)


    In congested areas the line construction engineer has to cope with a great variety of difficulties - amenity problems, line crossings, and road crossings. The authors describe the prerequisites for and the construction of a HV shared-service line of approx. 25 km in the congested area of Stuttgart, where several three-phase and single- phase a.c. systems are run on one set of pylons.

  16. Reestablishing Open Rotor as an Option for Significant Fuel Burn Improvements (United States)

    Van Zante, Dale


    A low-noise open rotor system is being tested in collaboration with General Electric and CFM International, a 50/50 joint company between Snecma and GE. Candidate technologies for lower noise will be investigated as well as installation effects such as pylon integration. Current test status is presented as well as future scheduled testing which includes the FAA/CLEEN test entry. Pre-test predictions show that Open Rotors have the potential for revolutionary fuel burn savings.

  17. Three-Dimensional Interactions and Vortical Flows with Emphasis on High Speeds (United States)


    pylons, boundary-layer diverters, and unfaired junctions of the wing and tail surfaces with the body are important examples (Meyer 1968; Peake, Rainbird...209, Jan. 1975. Fiechter, M., " Uber Wirbelsysteme an schlanken Rotationskbrpern und ihren Einfluss auf die aerodynamischen Beiwerte," Deutsch...10 0 O . ’ 1N . 2 .4 . .1LL 61 SHUTTLE WINDWARD SURFACE H4EATING FOR (d) CALCULATED WINDWARD VPAN*=S WIND- TUNNEL CONOITIONS M_ - 7.4% 1 EATING FOR

  18. Historical Quarries, Decay and Petrophysical Properties of Carbonate Stones Used in the Historical Center of Madrid (Spain

    Directory of Open Access Journals (Sweden)

    David M. Freire-Lista


    Full Text Available The carbonate stones that make up the four fountains of the 18th century located in the Paseo del Prado of Madrid (Spain are studied. The documentary search in historical archives, together with the petrographic, cartographic and paleontological studies permitted to determine that the fountains have been built with dolostone of the Castrojimeno Formation, with gastropods of the Trochactaeon Lamarcki specie of the Santonian (Upper Cretaceous. The historical quarries from which the ashlars have been extracted is located in Redueña Village. The petrophysical properties of this dolostone (effective porosity, bulk density, mercury intrusion porosity, ultrasound wave propagation velocity, micro-roughness and color have been calculated and compared with Colmenar de Oreja limestone. Each of the four fountains has a circular pylon at the base, a central column that holds a smaller pylon and is topped by a sculpture that serves as a spout. A bomb destroyed three ashlars of the basal pylon, column, small pylon and the sculpture of the SE fountain, during the Spanish Civil War, in 1936. These damaged elements were replaced by other carved limestones from Colmenar de Oreja in 1944. The four sculptures had been replaced in 1996 with resin replicas and the originals are preserved in the San Isidro. Los orígenes de Madrid museum. The study of the petrophysical properties of the sculptures located in the museum allowed us to determine the decay of different stone types. The analysis of micro-roughness was employed to define that the dissolution effect on the sculptures is different between dolostone and limestone. Redueña dolostone is more resistant to dissolution effect than Colmenar de Oreja limestome.

  19. Integration of the Residual Limb with Prostheses via Direct Skin-Bone-Peripheral Nerve Interface (United States)


    AWARD NUMBER: W81XWH-16-1-0791 TITLE: Integration of the Residual Limb with Prostheses via Direct Skin- Bone-Peripheral Nerve Interface...ABOVE ADDRESS. 1. REPORT DATE October 2017 2. REPORT TYPE Annual 3. DATES COVERED 30 Sep 2016 - 29 Sep 2017 4. TITLE AND SUBTITLE Integration of the...translational study to develop Skin and Bone Integrated Pylon with Peripheral Neural Interface (SBIP-PNI) directly attached to the residuum and the

  20. Winglet and long duct nacelle aerodynamic development for DC-10 derivatives (United States)

    Taylor, A. B.


    Advanced technology for application to the Douglas DC-10 transport is discussed. Results of wind tunnel tests indicate that the winglet offers substantial cruise drag reduction with less wing root bending moment penalty than a wing-tip extension of the same effectiveness and that the long duct nacelle offers substantial drag reduction potential as a result of aerodynamic and propulsion improvements. The aerodynamic design and test of the nacelle and pylon installation are described.

  1. Campylobacter pylori Detection in Gastric Mucosa: Association with Gastritis


    Paradis, Alain; Gourdeau, Marie; Lambert, Suzanne; Lavoie, Sylvain; Lemire, Suzanne; Parent, Claude; Cantin, Réjean


    ln order to evaluate the association between Camphlobacter pylori and gastritis, two biopsies were taken from the duodenal bulb, antrum, body and fundus (and from lesions if there were any) in 100 consecutive patients referred to this gastroscopic clinic For each site, one biopsy was for histology and C pylon detection by Warthin-Starry staining, and the second biopsy was for culture. In addition, for each patient a gastric brushing was Gram stained. Twenty-one patients were ex...

  2. Experiences with the first dry cooling tower for the THTR power plant at Schmehausen, FRG

    Energy Technology Data Exchange (ETDEWEB)

    Erdmann, W [Vereinigte Elektrizitaetswerke Westfalen AG (VEW), Dortmund (Germany, F.R.)


    The cable net cooling tower at Schmehausen was completed 12 years ago. Annual inspections are required by law. This paper reports on the following topics brought to light by these inspections: repair of damaged concrete on the pylon head; the search for a durable means of protecting the steel cables between the lifter ring and the thrust ring from corrosion; renewal of the attachment of the aluminium lining; cracks in the ring foundation; and weakening of the foundation anchors. (author).


    Directory of Open Access Journals (Sweden)



    Full Text Available The links created on all levels between the parent company and its subsidiaries have generated along time debates regarding the subterfugii to the regulations applicable in the audit activity in order to protect the above mentioned entities. Throughout this paper we will progressively describe the pylons that represent the foundation of the regulations subject to the audit activity in this organizational environment.

  4. Measurement of Forces and Moments Transmitted to the Residual Limb (United States)


    Interface Biomechanical Correlate Force X Anterior-Posterior Force Perpendicular to Pylon Anterior-Posterior Force on Limb Braking and produce noticeable pressure for level walking, going up stairs , up ramps, walking in a circle with the prosthetic foot inside and outside, and...0.3 Up Stairs Notch Throug hout 0.5 Notch Throug hout 0.3 Down Stairs Distal Tibia Popliteal Throughout Throughout 1 1 Distal Tibia Throughout

  5. The mechanics of landing when stepping down in unilateral lower-limb amputees. (United States)

    Jones, S F; Twigg, P C; Scally, A J; Buckley, J G


    The ability to successfully negotiate stairs and steps is an important factor for functional independence. While work has been undertaken to understand the biomechanics of gait in lower-limb amputees, little is known about how amputees negotiate stairs and steps. This study aimed to determine the mechanics of landing in unilateral lower-limb amputees when stepping down to a new level. A secondary aim was to assess the effects of using a shank-mounted shock-absorbing device (Tele-Torsion Pylon) on the mechanics of landing. Ten unilateral amputees (five transfemoral and five transtibial) and eight able-bodied controls performed single steps down to a new level (73 and 219 mm). Trials were repeated in amputees with the Tele-Torsion Pylon active and inactive. The mechanics of landing were evaluated by analysing peak limb longitudinal force, maximal limb shortening, lower extremity stiffness, and knee joint angular displacement during the initial contact period, and limb and ankle angle at the instant of ground-contact. Data were collected using a Vicon 3D motion analysis system and two force platforms. Amputees landed on a straightened and near vertical limb. This limb position was maintained in transfemoral amputees, whereas in transtibial amputees knee flexion occurred. As a result lower extremity stiffness was significantly greater in transfemoral amputees compared to transtibial amputees and able-bodied controls (P<0.001). The Tele-Torsion Pylon had little effect on the mechanics of landing in transtibial amputees, but brought about a reduction in lower extremity stiffness in transfemoral amputees (P<0.05). Amputees used a stepping strategy that ensured the direction of the ground reaction force vector was kept anterior of the knee joint centre. Using a Tele-Torsion Pylon may improve the mechanics of landing during downward stepping in transfemoral amputees.

  6. Wired: impacts of increasing power line use by a growing bird population (United States)

    Moreira, Francisco; Encarnação, Vitor; Rosa, Gonçalo; Gilbert, Nathalie; Infante, Samuel; Costa, Julieta; D'Amico, Marcello; Martins, Ricardo C.; Catry, Inês


    Power lines are increasingly widespread across many regions of the planet. Although these linear infrastructures are known for their negative impacts on bird populations, through collision and electrocution, some species take advantage of electricity pylons for nesting. In this case, estimation of the net impact of these infrastructures at the population level requires an assessment of trade-offs between positive and negative impacts. We compiled historical information (1958-2014) of the Portuguese white stork Ciconia ciconia population to analyze long-term changes in numbers, distribution range and use of nesting structures. White stork population size increased 660% up to 12000 breeding pairs between 1984 and 2014. In the same period, the proportion of nests on electricity pylons increased from 1% to 25%, likely facilitated by the 60% increase in the length of the very high tension power line grid (holding the majority of the nests) in the stork’s distribution range. No differences in breeding success were registered for storks nesting on electricity pylons versus other structures, but a high risk of mortality by collision and electrocution with power lines was estimated. We discuss the implications of this behavioral change, and of the management responses by power line companies, both for stork populations and for managers.

  7. Comparative simulation of wind park design and siting in Algeria

    International Nuclear Information System (INIS)

    Youcef Ettoumi, Fatiha; Adane, Abd El Hamid; Benzaoui, Mohamed Lassaad; Bouzergui, Nabila


    In this paper, five typical regions of Algeria where wind is strong enough are selected. These regions usually intended for traditional agriculture are, centred around the towns of Guelma, El Oued, Tindouf, Touggourt and Tamanrasset. To make wind energy conversion available as an alternative energy source for the populations living in such countries, nine types of small and medium wind turbines constructed by American and European manufacturers are studied for their suitability. To account for the wind variations with height, four possible heights of the pylon holding the turbines are considered: 10, 20, 40 and 60 m. In each of the five locations and at each pylon height, wind energy converted by the turbines, is cumulated over the year and computed. Depending on the site and their size, most of these turbines are found to produce about 1000-10,000 MWh of electricity per year at 60 m of altitude and can easily satisfy the electricity need in irrigation and its household applications in rustic and arid regions. A quick glance of the results of the above computation shows that the choice of pylons of 20 m height yields a trade-off between the production of electrical energy and the requirements of economy. Owing to the sporadic wind variations, wind energy conversion systems can only be used as an auxiliary source. In particular, these systems can advantageously be coupled to stand-alone photovoltaic conversion systems in remote locations or connected to the electric mains in urban zones. (author)

  8. Saker Falcon on the Crimean Peninsula

    Directory of Open Access Journals (Sweden)

    Igor V. Karyakin


    Full Text Available In this article we made a revaluation of a number of the Saker (Falco cherrug on the Crimean Peninsula based on data obtained in an expedition conducted in May 9–26 of 2015. During this expedition Sakers were observed on 58 sites (31 times they were seen on pylons of power lines, 14 – on cliffs in the foothills of Crimean Mountains, 8 – on the coastal cliffs and 4 on the coastal precipices, and one adult male was seen in the forest shelter belt near Syvash lagoon. We revealed 49 breeding territories of Saker including 42 occupied nests with successful breeding. The estimation of the total number of breeding population on peninsula is 145–184 (mean 165 breeding pairs, including 125–159 (mean 142 pairs which breeding attempts were successful in 2015. The distance between the neighboring pairs is 1.95–15.21 km (mean 6.56±3.37 km, n=43. Pylons of power lines were used by 30 breeding pairs (61.22% out of 49, and 29 successful nests (69.05% out of 42 were built on pylons. Supposedly, 63.83% of all breeding pairs in Crimea are bred on pylons, and the percentage of successful nests out of the total number of nests in population is 71.89%. From the 34 nests that were built on pylons, 24 (70.59% were located on the concrete pylons and 10 (29.41% on the metal ones. On cliffs and precipices we found 24 nests in total. Eighteen (75% of them were built on a bare ground, while the others were found in the nests built by other bird species (most of them were made in the former nests of the Raven (Corvus corax, and one pair occupies a nest of the Long-legged Buzzard (Buteo rufinus located on cliff. The percentage of successful nests out of occupied ones was 85.71%. We found broods of 1–4 nestlings, which in average (n=23 makes 2.83±0.78 nestling per successful nest. The majority of broods (65.22% consisted of 3 nestlings. On 20 breeding territories (90.91% male birds were older then 2 years old, and two breeding territories (9.09% were occupied

  9. Two-Dimensional Analysis of Cable Stayed Bridge under Wave Loading (United States)

    Seeram, Madhuri; Manohar, Y.


    In the present study finite element analysis is performed for a modified fan type cable-stayed bridge using ANSYS Mechanical. A cable stayed bridge with two towers and main deck is considered for the present study. Dynamic analysis is performed to evaluate natural frequencies. The obtained natural frequencies and mode shapes of cable stayed bridge are compared to the existing results. Further studies have been conducted for offshore area application by increasing the pylon/tower height depending upon the water depth. Natural frequencies and mode shapes are evaluated for the cable stayed bridge for offshore area application. The results indicate that the natural periods are higher than the existing results due to the effect of increase in mass of the structure and decrease in stiffness of the pylon/tower. The cable stayed bridge is analyzed under various environmental loads such as dead, live, vehicle, seismic and wave loading. Morison equation is considered to evaluate the wave force. The sum of inertia and drag force is taken as the wave force distribution along the fluid interacting height of the pylon. Airy's wave theory is used to assess water particle kinematics, for the wave periods ranging from 5 to 20 s and unit wave height. The maximum wave force among the different regular waves is considered in the wave load case. The support reactions, moments and deflections for offshore area application are highlighted. It is observed that the maximum support reactions and support moments are obtained due to wave and earthquake loading respectively. Hence, it is concluded that the wave and earthquake forces shall be given significance in the design of cable stayed bridge.

  10. Quality assurance and data collection -- Electronic Data Transfer

    International Nuclear Information System (INIS)

    Tomczak, L.M.; Lohner, W.G.; Ray, E.C.; Salesky, J.A.; Spitz, H.B.


    The Radiological Environmental Monitoring (REM) group at the Fernald Environmental Management Project is involved in an Electronic Data Transfer practice that will result in the improved quality assurance of collected data. This practice focuses on electronic data transfer from the recording instrument to reduce the manpower normally required for manual data entry and improve the quality of the data transferred. The application of this practice can enhance any data collection program where instruments with electronic memories and a signal output are utilized. Organizations employing this practice can strengthen the quality and efficiency of their data collection program. The use of these practices can assist in complying with Quality Assurance requirements under ASME NQA-1, RCRA, CERCLA, and DOE Order activities. Data from Pylon AB-5 instrumentation is typically configured to print data to a tape. The REM group has developed a process to electronically transfer stored data. The data are sent from the Pylon AB-5 field instrument to a HewlettPackard portable hand computer, model HP95LX. Data are recorded and stored on a 128 K-byte RAN card and later transferred to a PC database as an electronic file for analysis. The advantage of this system is twofold: (1) Data entry errors are eliminated and (2) considerable data collection and entry time is eliminated. Checks can then be conducted for data validity between recorded intervals due to light leaks etc. and the detection of outliers. This paper will discuss the interface and connector components that allow this transfer of data from the Pylon to the PC to take place and the process to perform that activity

  11. Measurement of waterborne radon in the drinking water of the Dera Ismail Khan city using active and passive techniques

    Directory of Open Access Journals (Sweden)

    Nasir Tabassum


    Full Text Available Groundwater is considered to be the second largest contributor to the indoor radon concentration after soil. Therefore, measurement of waterborne radon has remained a point of interest for many researchers. The main objective of this study is to study waterborne radon activity in the city of Dera Ismail Khan. In this context, water samples were collected from different locations of the city and waterborne radon was measured using a pylon vacuum water degassing system and CR-39 based radon detectors. The pylon system measured waterborne radon activities in samples of hand pumps and motor driven pumps varying from 0.015 to 0.066 Bq/L and 0.021 to 0.145 Bq/L with average values of 0.041 ± 0.015 Bq/L and 0.076 ± 0.024 Bq/L, respectively. Whereas CR-39 based measured values ranged from 0.042 to 0.125 Bq/L and 0.075 to 0.158 Bq/L with average values of 0.081 ± 0.021 Bq/L and 0.120 ± 0.020 Bq/L, respectively. The estimated average annual effective dose due to ingestion of radon from drinking water using pylon and CR-39 based radon detectors for hand and motor pump samples was found to be 1.055×10-4 mSv and 1.947×10-4 mSv, and 2.067×10-4 mSv and 3.058×10-4 mSv, respectively. The waterborne radon concentrations and as a result the annual effective dose expected to be received from it are within the recommended safe limits.

  12. Experimental procedure for the determination of counting efficiency and sampling flow rate of a grab-sampling working level meter

    International Nuclear Information System (INIS)

    Grenier, M.; Bigu, J.


    The calibration procedures used for a working level meter (WLM) of the grab-sampling type are presented in detail. The WLM tested is a Pylon WL-1000C working level meter and it was calibrated for radon/thoron daughter counting efficiency (E), for sampling pump flow rate (Q) and other variables of interest. For the instrument calibrated at the Elliot Lake Laboratory, E was 0.22 +- 0.01 while Q was 4.50 +- 0.01 L/min

  13. Next-Generation Web Frameworks in Python

    CERN Document Server

    Daly, Liza


    With its flexibility, readability, and maturecode libraries, Python is a naturalchoice for developing agile and maintainableweb applications. Severalframeworks have emerged in the last fewyears that share ideas with Ruby on Railsand leverage the expressive nature of Python.This Short Cut will tell you whatyou need to know about the hottest fullstackframeworks: Django, Pylons, andTurboGears. Their philosophies, relativestrengths, and development status aredescribed in detail. What you won't find out is, "Which oneshould I use?" The short answer is thatall of them can be used to build web appl

  14. Materials by Design - Computational Alloy Design for Corrosion (United States)


    Es = + 0.33 eV Cs Rb K · ~·Ba Sr ::~ \\ H ~ YCd ./ G B FS A~ Zn " Be• ’f_ Ni?.Au SeA. ’\\ . At-v Rh Ru • Zr Ja Mo Tc _,. • • • pt • lr Nb w...Windows Air Conditioning Autoflight Electrical Power Navigation Engine Exhaust Stabilizer Doors Fuel system Nacelles/Pylons Power Plant Equip...p. 14 ASETSDefense 2011: Sustainable Surface Engineering for Aerospace and Defense Workshop Quantum Mechanics Insights into SCC resistance 3.5 -E 0

  15. Aerodynamic Loads and Separation Characteristics of the BLU-27B/B, MK- 82SE, and GBU-8 Weapons in the F-16 Aircraft Flow Field at Mach Numbers from 0.4 to 1.2 (United States)


    76-147 Cm 1.2 0.8 o.q 0 SIMBOL CONFIG = ~ STORE ® IS E 0.60 MK-SESE m 15 E 0.80 MK-SESE IS E 0.90 MK-82SE IS E 0.95 MK-B2SE PYLON RRCK 6 M...0 10 .0 1 2 6 A E D C - T R - 7 6 - 1 4 7 SIMBOL CONFIG = H. STORE PILON RICK ~tt 0 11 I0 0.80 MK-82SE 7 I - 3 0 B II 10 0.60 HR-B2SE 7 T

  16. Probabilistic and sensitivity analysis of Botlek Bridge structures

    Directory of Open Access Journals (Sweden)

    Králik Juraj


    Full Text Available This paper deals with the probabilistic and sensitivity analysis of the largest movable lift bridge of the world. The bridge system consists of six reinforced concrete pylons and two steel decks 4000 tons weight each connected through ropes with counterweights. The paper focuses the probabilistic and sensitivity analysis as the base of dynamic study in design process of the bridge. The results had a high importance for practical application and design of the bridge. The model and resistance uncertainties were taken into account in LHS simulation method.

  17. Optimal Damping of Stays in Cable-Stayed Bridges for In-Plane Vibrations

    DEFF Research Database (Denmark)

    Jensen, C.N.; Nielsen, S.R.K.; Sørensen, John Dalsgaard


    cable-stayed bridges are often designed as twin cables with a spacing of, say 1m. In such cases, it is suggested in the paper to suppress the mentioned in-plane types of vibrations by means of a tuned mass–damper (TMD) placed between the twin cables at their midpoints. The TMD divides the stay into four......Significant vibrations have been reported in stays of recently constructed cable stayed bridges. The vibrations appear as in-plane vibrations that may be caused by rain–wind- induced aeroelastic interaction or by resonance excitation of the cables from the motion of the pylons. The stays of modern...

  18. Determination of Minimum Air Clearances for a 420kV Novel Unibody Composite Cross-Arm

    DEFF Research Database (Denmark)

    Jahangiri, Tohid; Bak, Claus Leth; Silva, Filipe Miguel Faria da


    One of the most important requirements of any overhead line tower is determining the air clearances between live parts and earthed parts such as phase conductor and tower structure. In contrast to traditional steel lattice towers, the recently introduced fully composite pylon is completely made....... This paper presents the insulation coordination studies to determine minimum required air clearances on the unibody cross-arm. The procedure and relevant equations to calculate minimum air clearances to avoid flashover between phases’ conductors as well as top phase conductor and shield wire are based...

  19. Modal Based Fatigue Monitoring of Steel Structures

    DEFF Research Database (Denmark)

    Graugaard-Jensen, J.; Brincker, Rune; Hjelm, H. P.


    In this paper it is shown how the accumulated fatigue in steel structures can be estimated with high accuracy by continuously measuring the accelerations in a few points of the structure. First step is to obtain a good estimate of the mode shapes by performing a natural input modal analysis. The so...... by applying the mode shapes of the calibrated Finite Element model and strains are obtained using the shape functions for the actual elements. The technique has been applied on a model frame structure in the laboratory and on a wind loaded lattice pylon structure. In both cases the estimated stresses has been...

  20. Modelling flow phenomena in time dependent store release from transonic aircraft

    CSIR Research Space (South Africa)

    MacLucas, David A


    Full Text Available Center (AEDC) [3] at angle of attack α=0° and Mach number M = 0.95. In the carriage position the separation distance of the store from the pylon was 0.070 inches. Data corrections may be found in the original report. The test case was conducted at a...-generated store grid through a background grid attached to the wing. Grids are illustrated in Figure 2 below. Refinement zones were also generated for both the parent and the release corridor. These assist with increasing the grid resolution in these areas...

  1. Establishing a Multi-spatial Wireless Sensor Network to Monitor Nitrate Concentrations in Soil Moisture (United States)

    Haux, E.; Busek, N.; Park, Y.; Estrin, D.; Harmon, T. C.


    The use of reclaimed wastewater for irrigation in agriculture can be a significant source of nutrients, in particular nitrogen species, but its use raises concern for groundwater, riparian, and water quality. A 'smart' technology would have the ability to measure wastewater nutrients as they enter the irrigation system, monitor their transport in situ and optimally control inputs with little human intervention, all in real-time. Soil heterogeneity and economic issues require, however, a balance between cost and the spatial and temporal scales of the monitoring effort. Therefore, a wireless and embedded sensor network, deployed in the soil vertically across the horizon, is capable of collecting, processing, and transmitting sensor data. The network consists of several networked nodes or 'pylons', each outfitted with an array of sensors measuring humidity, temperature, precipitation, soil moisture, and aqueous nitrate concentrations. Individual sensor arrays are controlled by a MICA2 mote (Crossbow Technology Inc., San Jose, CA) programmed with TinyOS (University of California, Berkeley, CA) and a Stargate (Crossbow Technology Inc., San Jose, CA) base-station capable of GPRS for data transmission. Results are reported for the construction and testing of a prototypical pylon at the benchtop and in the field.

  2. Social representations of electricity network technologies: exploring processes of anchoring and objectification through the use of visual research methods. (United States)

    Devine-Wright, Hannah; Devine-Wright, Patrick


    The aim of this study was to explore everyday thinking about the UK electricity network, in light of government policy to increase the generation of electricity from renewable energy sources. Existing literature on public perceptions of electricity network technologies was broadened by adopting a more socially embedded conception of the construction of knowledge using the theory of social representations (SRT) to explore symbolic associations with network technologies. Drawing and association tasks were administered within nine discussion groups held in two places: a Scottish town where significant upgrades to the local transmission network were planned and an English city with no such plans. Our results illustrate the ways in which network technologies, such as high voltage (HV) pylons, are objectified in talk and drawings. These invoked positive as well as negative symbolic and affective associations, both at the level of specific pylons, and the 'National Grid' as a whole and are anchored in understanding of other networks such as mobile telecommunications. We conclude that visual methods are especially useful for exploring beliefs about technologies that are widespread, proximal to our everyday experience but nevertheless unfamiliar topics of everyday conversation.

  3. Effects of winglet on transonic flutter characteristics of a cantilevered twin-engine-transport wing model (United States)

    Ruhlin, C. L.; Bhatia, K. G.; Nagaraja, K. S.


    A transonic model and a low-speed model were flutter tested in the Langley Transonic Dynamics Tunnel at Mach numbers up to 0.90. Transonic flutter boundaries were measured for 10 different model configurations, which included variations in wing fuel, nacelle pylon stiffness, and wingtip configuration. The winglet effects were evaluated by testing the transonic model, having a specific wing fuel and nacelle pylon stiffness, with each of three wingtips, a nonimal tip, a winglet, and a nominal tip ballasted to simulate the winglet mass. The addition of the winglet substantially reduced the flutter speed of the wing at transonic Mach numbers. The winglet effect was configuration-dependent and was primarily due to winglet aerodynamics rather than mass. Flutter analyses using modified strip-theory aerodynamics (experimentally weighted) correlated reasonably well with test results. The four transonic flutter mechanisms predicted by analysis were obtained experimentally. The analysis satisfactorily predicted the mass-density-ratio effects on subsonic flutter obtained using the low-speed model. Additional analyses were made to determine the flutter sensitivity to several parameters at transonic speeds.

  4. Design of Experimental Suspended Footbridge with Deck Made of UHPC

    Directory of Open Access Journals (Sweden)

    Blank Marek


    Full Text Available This paper deals with the static and dynamic design of experimental footbridge for pedestrians and cyclists in the municipality Lužec nad Vltavou in Czech Republic, Europe. This work aims to familiarize the reader with calculations carried out and the results obtained, describing the static and dynamic properties of proposed footbridge. The construction of footbridge is designed as a suspended structure with prestressed bridge deck consisting of prefabricated UHPC panels and reversed “V” shaped steel pylon with height of approximately 40 meters. The deck is anchored using 24 steel hangers in one row in a steel pylon - 17 ropes in the main span and 7 cables on the other side. Range of the main span is 99.18 meters and the secondary span is 31.9 m. Deck width is 4.5 meters with 3.0 meters passing space. The bridge is designed for the possibility of passage of vehicles weighting up to 3.5 tons. Deck panels are made of UHPC with reinforcement. At the edge of the bridge on the side of the shorter span the bridge deck is firmly connected with abutment and on the other deck it is stored using a pair of sliding bearings. The utilization of the excellent properties of UHPC allows to design a very thin and lightweight construction of the deck, which could not be achieved with the use of normal concrete.

  5. Modal analysis of cable-stayed UHPC bridge

    Directory of Open Access Journals (Sweden)

    Tej Petr


    Full Text Available This paper deals with the dynamic analysis of cable-stayed UHPC bridge over the Vltava river near town Melnik in Czech Republic, Europe. Bridge serves for pedestrians and cyclists. This work aims to familiarize the reader with dynamic calculations carried out and the results obtained, describing the dynamic properties of proposed bridge. The construction of bridge is designed as a cable-stayed structure with prestressed bridge deck consisting of prefabricated UHPC panels and reversed “V” shaped steel pylon with height of approximately 40 meters. The deck is anchored using 24 steel hangers in one row in a steel pylon - 17 ropes in the main span and 7 cables on the other side. Range of the main span is 99.18 meters and the secondary span is 31.9 m. Deck width is 4.5 meters with 3.0 meters passing space. The bridge is designed for the possibility of passage of vehicles weighting up to 3.5 tonnes. Deck panels are made of UHPC with reinforcement. At the edge of the bridge on the side of the shorter span the bridge deck is firmly connected with abutment and on the other deck it is stored using a pair of sliding bearings.

  6. Influence of soil zinc concentrations on zinc sensitivity and functional diversity of microbial communities

    International Nuclear Information System (INIS)

    Lock, K.; Janssen, C.R.


    Pollution induced community tolerance (PICT) is based on the phenomenon that toxic effects reduce survival of the most sensitive organisms, thus increasing community tolerance. Community tolerance for a contaminant is thus a strong indicator for the presence of that contaminant at the level of adverse concentrations. Here we assessed PICT in 11 soils contaminated with zinc runoff from galvanised electricity pylons and 11 reference soils sampled at 10 m distance from these pylons. Using PICT, the influence of background concentration and bioavailability of zinc on zinc sensitivity and functional diversity of microbial communities was assessed. Zinc sensitivity of microbial communities decreased significantly with increasing zinc concentrations in pore water and calcium chloride extracted fraction while no significant relationship was found with total zinc concentration in the soil. It was also found that functional diversity of microbial communities decreased with increasing zinc concentrations, indicating that increased tolerance is indeed an undesirable phenomenon when environmental quality is considered. The hypothesis that zinc sensitivity of microbial communities is related to background zinc concentration in pore water could not be confirmed. - Zinc sensitivity of microbial communities and functional diversity decrease with increasing zinc concentration in the pore water

  7. A new multiconstraint method for determining the optimal cable stresses in cable-stayed bridges. (United States)

    Asgari, B; Osman, S A; Adnan, A


    Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

  8. Research on Collapse Process of Cable-Stayed Bridges under Strong Seismic Excitations

    Directory of Open Access Journals (Sweden)

    Xuewei Wang


    Full Text Available In order to present the collapse process and failure mechanism of long-span cable-stayed bridges under strong seismic excitations, a rail-cum-road steel truss cable-stayed bridge was selected as engineering background, the collapse failure numerical model of the cable-stayed bridge was established based on the explicit dynamic finite element method (FEM, and the whole collapse process of the cable-stayed bridge was analyzed and studied with three different seismic waves acted in the horizontal longitudinal direction, respectively. It can be found from the numerical simulation analysis that the whole collapse failure process and failure modes of the cable-stayed bridge under three different seismic waves are similar. Furthermore, the piers and the main pylons are critical components contributing to the collapse of the cable-stayed bridge structure. However, the cables and the main girder are damaged owing to the failure of piers and main pylons during the whole structure collapse process, so the failure of cable and main girder components is not the main reason for the collapse of cable-stayed bridge. The analysis results can provide theoretical basis for collapse resistance design and the determination of critical damage components of long-span highway and railway cable-stayed bridges in the research of seismic vulnerability analysis.

  9. A New Multiconstraint Method for Determining the Optimal Cable Stresses in Cable-Stayed Bridges

    Directory of Open Access Journals (Sweden)

    B. Asgari


    Full Text Available Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM. The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

  10. Seismic Responses of a Cable-Stayed Bridge with Consideration of Uniform Temperature Load

    Directory of Open Access Journals (Sweden)

    Junjun Guo


    Full Text Available The effects of temperature load on the dynamic responses of cable-stayed bridges have attracted the attention of researchers in recent years. However, these investigations mainly focus on the influence of temperature on the dynamic characteristics of structures, such as vibration mode and frequency. This paper discusses the effects of uniform temperature changes on the seismic responses of a cable-stayed bridge. A three dimensional finite element model of a cable-stayed bridge using OpenSees is established for nonlinear time history analysis, and uniform temperature load is applied to the prototype bridge before the conducting of seismic excitation. Three ground motion records are selected from the PEER strong motion database based on the design spectrum. Case studies are then performed considering the varying temperature and the connections between the deck and pylons of the bridge. The result shows that the seismic responses of the bridge are significantly increased with the consideration of temperature load. Meanwhile, the types between the deck and pylon also have notable impacts on the seismic responses of the bridge with and without temperature changes. This research could provide a reference for designers during the design phase of cable-stayed brides.

  11. Summary of Data from the Sixth AIAA CFD Drag Prediction Workshop: CRM Cases 2 to 5 (United States)

    Tinoco, Edward N.; Brodersen, Olaf P.; Keye, Stefan; Laflin, Kelly R.; Feltrop, Edward; Vassberg, John C.; Mani, Mori; Rider, Ben; Wahls, Richard A.; Morrison, Joseph H.; hide


    Results from the Sixth AIAA CFD Drag Prediction Workshop Common Research Model Cases 2 to 5 are presented. As with past workshops, numerical calculations are performed using industry-relevant geometry, methodology, and test cases. Cases 2 to 5 focused on force/moment and pressure predictions for the NASA Common Research Model wing-body and wing-body-nacelle-pylon configurations, including Case 2 - a grid refinement study and nacelle-pylon drag increment prediction study; Case 3 - an angle-of-attack buffet study; Case 4 - an optional wing-body grid adaption study; and Case 5 - an optional wing-body coupled aero-structural simulation. The Common Research Model geometry differed from previous workshops in that it was deformed to the appropriate static aeroelastic twist and deflection at each specified angle-of-attack. The grid refinement study used a common set of overset and unstructured grids, as well as user created Multiblock structured, unstructured, and Cartesian based grids. For the supplied common grids, six levels of refinement were created resulting in grids ranging from 7x10(exp 6) to 208x10(exp 6) cells. This study (Case 2) showed further reduced scatter from previous workshops, and very good prediction of the nacelle-pylon drag increment. Case 3 studied buffet onset at M=0.85 using the Medium grid (20 to 40x10(exp 6) nodes) from the above described sequence. The prescribed alpha sweep used finely spaced intervals through the zone where wing separation was expected to begin. Although the use of the prescribed aeroelastic twist and deflection at each angle-of-attack greatly improved the wing pressure distribution agreement with test data, many solutions still exhibited premature flow separation. The remaining solutions exhibited a significant spread of lift and pitching moment at each angle-of-attack, much of which can be attributed to excessive aft pressure loading and shock location variation. Four Case 4 grid adaption solutions were submitted. Starting

  12. Required coefficient of friction during turning at self-selected slow, normal, and fast walking speeds. (United States)

    Fino, Peter; Lockhart, Thurmon E


    This study investigated the relationship of required coefficient of friction to gait speed, obstacle height, and turning strategy as participants walked around obstacles of various heights. Ten healthy, young adults performed 90° turns around corner pylons of four different heights at their self selected normal, slow, and fast walking speeds using both step and spin turning strategies. Kinetic data was captured using force plates. Results showed peak required coefficient of friction (RCOF) at push off increased with increased speed (slow μ=0.38, normal μ=0.45, and fast μ=0.54). Obstacle height had no effect on RCOF values. The average peak RCOF for fast turning exceeded the OSHA safety guideline for static COF of μ>0.50, suggesting further research is needed into the minimum static COF to prevent slips and falls, especially around corners. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Requirements of titanium alloys for aeronautical industry (United States)

    Ghiban, Brânduşa; Bran, Dragoş-Teodor; Elefterie, Cornelia Florina


    The project presents the requirements imposed for aeronatical components made from Titanium based alloys. Asignificant portion of the aircraft pylons are manufactured from Titanium alloys. Strength, weight, and reliability are the primary factors to consider in aircraft structures. These factors determine the requirements to be met by any material used to construct or repair the aircraft. Many forces and structural stresses act on an aircraft when it is flying and when it is static and this thesis describes environmental factors, conditions of external aggression, mechanical characteristics and loadings that must be satisfied simultaneously by a Ti-based alloy, compared to other classes of aviation alloys (as egg. Inconel super alloys, Aluminum alloys). For this alloy class, the requirements are regarding strength to weight ratio, reliability, corrosion resistance, thermal expansion and so on. These characteristics additionally continue to provide new opportunities for advanced manufacturing methods.

  14. Aeronautical Industry Requirements for Titanium Alloys (United States)

    Bran, D. T.; Elefterie, C. F.; Ghiban, B.


    The project presents the requirements imposed for aviation components made from Titanium based alloys. A significant portion of the aircraft pylons are manufactured from Titanium alloys. Strength, weight, and reliability are the primary factors to consider in aircraft structures. These factors determine the requirements to be met by any material used to construct or repair the aircraft. Many forces and structural stresses act on an aircraft when it is flying and when it is static and this thesis describes environmental factors, conditions of external aggression, mechanical characteristics and loadings that must be satisfied simultaneously by a Ti-based alloy, compared to other classes of aviation alloys (as egg. Inconel super alloys, Aluminum alloys).For this alloy class, the requirements are regarding strength to weight ratio, reliability, corrosion resistance, thermal expansion and so on. These characteristics additionally continue to provide new opportunities for advanced manufacturing methods.

  15. Reduction of sources of error and simplification of the Carbon-14 urea breath test

    International Nuclear Information System (INIS)

    Bellon, M.S.


    Full text: Carbon-14 urea breath testing is established in the diagnosis of H. pylori infection. The aim of this study was to investigate possible further simplification and identification of error sources in the 14 C urea kit extensively used at the Royal Adelaide Hospital. Thirty six patients with validated H. pylon status were tested with breath samples taken at 10,15, and 20 min. Using the single sample value at 15 min, there was no change in the diagnostic category. Reduction or errors in analysis depends on attention to the following details: Stability of absorption solution, (now > 2 months), compatibility of scintillation cocktail/absorption solution. (with particular regard to photoluminescence and chemiluminescence), reduction in chemical quenching (moisture reduction), understanding counting hardware and relevance, and appropriate response to deviation in quality assurance. With this experience, we are confident of the performance and reliability of the RAPID-14 urea breath test kit now available commercially

  16. Radon gas exposure levels in some selected areas in Egypt

    International Nuclear Information System (INIS)

    Ali, E.M.; Taha, T.M.; Gomaa, M.A.; El-Hussein, A.M.; Ahmed, A.A.


    During a summer season of 2003, the atmospheric concentrations of radon gas were measured indoor every one-hour for twenty-four hour measurements in some selected areas, using Pylon-AB4. Two hundreds and forty samples were monitored to determine the concentration of radon gas at each location using high-efficiency Lucas type continuous passive cell. The average values of radon gas concentration were taken in three time intervals 6.00:18.00, 18.00:6.00 and whole day. The average values of indoor radon gas of two locations using three time intervals were 4.82±0.63, 9±0.71 and 6.9±0.33 and 9.6±0.23, 11.82±0.42 and 9.37±0.7 Bq/m /h. respectively. The exposure levels were within the ICRP and EPA recommendations

  17. Construction of a 500 kV aerial power line in East Java

    Energy Technology Data Exchange (ETDEWEB)

    Kaeufl, O; Paschen, R; Kummermehr, R


    The authors report on the technical preparations and the construction of a 500 kv, four-bundle power line with a pylon tonnage of approximately 10,000 t of steel and a route length of 251 km in Indonesia. Due to the difficult terrain conditions, the sensitive infrastructure and the extremely short construction period, this project was a special technological challenge. Initially, the authors explain the technical planning of Brown Boveri with emphasis on foundations and assembly. As part of this tailor-made concept new technological solutions were used. They were instrumental in the successful completion of the project in only 19 months by the end of 1986 to the complete satisfaction of the customer. The authors also comment on the pracitcal experiences gained during the construction.

  18. Lessons in the Design and Characterization Testing of the Semi-Span Super-Sonic Transport (S4T) Wind-Tunnel Model (United States)


    This paper focuses on some of the more challenging design processes and characterization tests of the Semi-Span Super-Sonic Transport (S4T)-Active Controls Testbed (ACT). The model was successfully tested in four entries in the National Aeronautics and Space Administration Langley Transonic Dynamics Tunnel to satisfy the goals and objectives of the Fundamental Aeronautics Program Supersonic Project Aero-Propulso-Servo-Elastic effort. Due to the complexity of the S4T-ACT, only a small sample of the technical challenges for designing and characterizing the model will be presented. Specifically, the challenges encountered in designing the model include scaling the Technology Concept Airplane to model scale, designing the model fuselage, aileron actuator, and engine pylons. Characterization tests included full model ground vibration tests, wing stiffness measurements, geometry measurements, proof load testing, and measurement of fuselage static and dynamic properties.

  19. Characterization of Fibre-Direction Dependent Damping of Glass-Fibre Composites at Low Temperatures and Low Frequencies

    DEFF Research Database (Denmark)

    Kliem, Mathias; Høgsberg, Jan Becker; Dannemann, Martin


    This paper deals with the characterization of the fibre-direction dependent damping capability of glass fibre reinforced plastics (GFRP) to be used in electrical power transmission pylons. A fibre-direction dependent damping analysis of unidirectional (UD) GFRP samples was carried out using...... a Dynamic Mechanical Analysis (DMA) for five different fibre orientations (0˚ | 30˚ | 45˚ | 60˚ and 90˚) and two different matrix systems (epoxy and a vinyl ester resin). Based on the dynamic characteristics the damping performance of the various composite materials was studied at three temperatures (-10˚C......, 0˚C and 10˚C) and three vibration frequencies (1 Hz, 10 Hz and 30 Hz). It was observed that the loss factor of Glass Fibre Reinforced Vinyl-Ester (GF-VE) was in general slightly higher compared to the Glass Fibre Reinforced Epoxy (GF-EP). The loss factor increased slightly with temperature, while...

  20. The Penguin: a Low Reynolds Number Powered Glider for Station Keeping Missions (United States)

    Costello, J. K.; Greene, D. W.; Lee, T. T.; Matier, P. T.; Mccarthy, T. R.; Mcguire, R. J.; Schuette, M. J.


    The Penguin is a low Reynolds number (approx. 100,000) remotely piloted vehicle (RPV). It was designed to fly three laps indoors around two pylons in a figure-eight course while maximizing loiter time. The Penguin's low Reynolds number mission is an important one currently being studied for possible future flights in the atmospheres of other planets and for specialized military missions. Although the Penguin's mission seemed quite simple at first, the challenges of such low Reynolds number flight have proven to be quite unique. In addition to the constraint of low Reynolds number flight, the aircraft had to be robust in its control, highly durable, and it had to carry a small instrument package. The Penguin's flight plan, concept, performance, aerodynamic design, weight estimation, structural design, propulsion, stability and control, and cost estimate is detailed.

  1. A study to define the research and technology requirements for advanced turbo/propfan transport aircraft (United States)

    Goldsmith, I. M.


    The feasibility of the propfan relative to the turbofan is summarized, using the Douglas DC-9 Super 80 (DS-8000) as the actual operational base aircraft. The 155 passenger economy class aircraft (31,775 lb 14,413 kg payload), cruise Mach at 0.80 at 31,000 ft (8,450 m) initial altitude, and an operational capability in 1985 was considered. Three propfan arrangements, wing mounted, conventional horizontal tail aft mounted, and aft fuselage pylon mounted are selected for comparison with the DC-9 Super 80 P&WA JT8D-209 turbofan powered aircraft. The configuration feasibility, aerodynamics, propulsion, structural loads, structural dynamics, sonic fatigue, acoustics, weight maintainability, performance, rough order of magnitude economics, and airline coordination are examined. The effects of alternate cruise Mach number, mission stage lengths, and propfan design characteristics are considered. Recommendations for further study, ground testing, and flight testing are included.

  2. Effect of humidity on thoron adsorption in activated charcoal bed

    International Nuclear Information System (INIS)

    Sudeep Kumara, K.; Karunakara, N.; Yashodhara, I.; Sapra, B.K.; Sahoo, B.K.; Gaware, J.J.; Kanse, S.D.; Mayya, Y.S.


    Activated charcoal is a well-known adsorber of 222 Rn and 220 Rn gases. This property can be effectively used for remediation of these gases in the workplaces of uranium and thorium processing facilities. However, the adsorption on charcoal is sensitive to variation in temperature and humidity. The successful designing and characterization of adsorption systems require an adequate understanding of these sensitivities. The study has been carried out towards this end, to delineate the effect of relative humidity on the efficacy of 220 Rn mitigations in a charcoal bed. Air carrying 220 Rn from a Pylon source was passed through a column filled with coconut shell-based granular activated charcoal. The relative humidity of the air was controlled, and the transmission characteristics were examined at relative humidity varying from 45% to 60%. The mitigation factor was found to decrease significantly with an increase of humidity in the air. (author)

  3. Studies on aerodynamic interferences between the components of transport airplane using unstructured Navier-Stokes simulations

    International Nuclear Information System (INIS)

    Wang, G.; Ye, Z.


    It is well known that the aerodynamic interference flows widely exist between the components of conventional transport airplane, for example, the wing-fuselage juncture flow, wing-pylon-nacelle flow and tail-fuselage juncture flow. The main characteristic of these aerodynamic interferences is flow separation, which will increase the drag, reduce the lift and cause adverse influence on the stability and controllability of the airplane. Therefore, the modern civil transport designers should do their best to eliminate negative effects of aerodynamic interferences, which demands that the aerodynamic interferences between the aircraft components should be predicted and analyzed accurately. Today's CFD techniques provide us powerful and efficient analysis tools to achieve this objective. In this paper, computational investigations of the interferences between transport aircraft components have been carried out by using a viscous flow solver based on mixed element type unstructured meshes. (author)

  4. Effects of external stores on the air combat capability of a delta wing fighter (United States)

    Spearman, M. L.; Sawyer, W. C.


    Delta wing point-design fighters with two pylon mounted missiles and aft tail controls (similar to several Soviet designs) have been investigated for a Mach number range from about 0.6 to 2.0. Whereas minimum drag penalties that are expected with the addition of external stores do occur, the effects at higher lifts, corresponding to maneuvering flight, are less severe and often favorable. The drag-due-to-lift factor is less with stores on although the lift curve slope is unaffected. The longitudinal stability level is reduced by the addition of stores while the pitch control effectiveness is unchanged. The directional stability was generally reduced at subsonic speeds and increased at supersonic speeds by the addition of stores but sufficiently high stability levels are obtainable that are compatible with the longitudinal maneuvering limits. Some examples of the potential maneuvering capability in terms of normal acceleration and turn radius are included.

  5. Generation After Next Propulsor Research: Robust Design for Embedded Engine Systems (United States)

    Arend, David J.; Tillman, Gregory; O'Brien, Walter F.


    The National Aeronautics and Space Administration, United Technologies Research Center and Virginia Polytechnic and State University have contracted to pursue multi-disciplinary research into boundary layer ingesting (BLI) propulsors for generation after next environmentally responsible subsonic fixed wing aircraft. This Robust Design for Embedded Engine Systems project first conducted a high-level vehicle system study based on a large commercial transport class hybrid wing body aircraft, which determined that a 3 to 5 percent reduction in fuel burn could be achieved over a 7,500 nanometer mission. Both pylon-mounted baseline and BLI propulsion systems were based on a low-pressure-ratio fan (1.35) in an ultra-high-bypass ratio engine (16), consistent with the next generation of advanced commercial turbofans. An optimized, coupled BLI inlet and fan system was subsequently designed to achieve performance targets identified in the system study. The resulting system possesses an inlet with total pressure losses less than 0.5%, and a fan stage with an efficiency debit of less than 1.5 percent relative to the pylon-mounted, clean-inflow baseline. The subject research project has identified tools and methodologies necessary for the design of next-generation, highly-airframe-integrated propulsion systems. These tools will be validated in future large-scale testing of the BLI inlet / fan system in NASA's 8 foot x 6 foot transonic wind tunnel. In addition, fan unsteady response to screen-generated total pressure distortion is being characterized experimentally in a JT15D engine test rig. These data will document engine sensitivities to distortion magnitude and spatial distribution, providing early insight into key physical processes that will control BLI propulsor design.

  6. Puente de Humber Gran Bretaña

    Directory of Open Access Journals (Sweden)

    Población Knappe, Eleuterio


    Full Text Available This article describes the building of the world's longest single- span hanging bridge (2,250 metres in the Humber estuary. The floor of this bridge, the main light of which Is 1,410 m, is formed by trapezoidal chestbeams made with 18 m long rigid sheets. This makes possible both economy of steel and a reduction In the dimensions of the cables, pylons and anchorage masses. The pylons, built of sliding formwork, consist of two 155 m high reinforced concrete hollow pillars.These pillars are joined by four horizontal struts. The construction of the Humber bridge allows the distances between both shores of the estuary to be cut and completes the motorway network in the area.

    Se describe en este artículo la construcción del puente colgado de tramo sencillo más largo del mundo (2.250 m en el estuario de Humber. El tablero de este puente, cuya luz principal es de 1.410 m, está formado por vigas-cajón trapezoidales realizadas mediante chapas rigidizadas de 18 m de longitud. De esta manera se obtiene una economía de acero así como una reducción en las dimensiones de los cables, pilonos y macizos de anclaje. Los pilonos, construidos con encofrado deslizante, se componen de dos pilares huecos de hormigón armado de 155 m de altura. Estos pilares están unidos por cuatro riostras horizontales. La construcción del puente de Humber permite acortar las distancias entre ambas orillas del estuario y completa la red de autopistas de la zona.

  7. Flow simulations about steady-complex and unsteady moving configurations using structured-overlapped and unstructured grids (United States)

    Newman, James C., III


    The limiting factor in simulating flows past realistic configurations of interest has been the discretization of the physical domain on which the governing equations of fluid flow may be solved. In an attempt to circumvent this problem, many Computational Fluid Dynamic (CFD) methodologies that are based on different grid generation and domain decomposition techniques have been developed. However, due to the costs involved and expertise required, very few comparative studies between these methods have been performed. In the present work, the two CFD methodologies which show the most promise for treating complex three-dimensional configurations as well as unsteady moving boundary problems are evaluated. These are namely the structured-overlapped and the unstructured grid schemes. Both methods use a cell centered, finite volume, upwind approach. The structured-overlapped algorithm uses an approximately factored, alternating direction implicit scheme to perform the time integration, whereas, the unstructured algorithm uses an explicit Runge-Kutta method. To examine the accuracy, efficiency, and limitations of each scheme, they are applied to the same steady complex multicomponent configurations and unsteady moving boundary problems. The steady complex cases consist of computing the subsonic flow about a two-dimensional high-lift multielement airfoil and the transonic flow about a three-dimensional wing/pylon/finned store assembly. The unsteady moving boundary problems are a forced pitching oscillation of an airfoil in a transonic freestream and a two-dimensional, subsonic airfoil/store separation sequence. Accuracy was accessed through the comparison of computed and experimentally measured pressure coefficient data on several of the wing/pylon/finned store assembly's components and at numerous angles-of-attack for the pitching airfoil. From this study, it was found that both the structured-overlapped and the unstructured grid schemes yielded flow solutions of

  8. B-52 Flight Mission Symbology on Side of Craft (United States)


    aerodynamic and structural testing). The aircraft supported the development of parachute recovery systems used to recover the space shuttle solid rocket booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet. The heaviest load it has carried was the No. 2 X-15 aircraft at 53,100 pounds. Project manager for the aircraft is Roy Bryant.

  9. B-52 Flight Mission Symbology - Close up (United States)


    eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet.. It is 156 feet long and has a wing span of 185 feet. The heaviest load it has carried was the No. 2 X-15 aircraft at 53,100 pounds. Project manager for the aircraft is Roy Bryant.

  10. Turboelectric Distributed Propulsion in a Hybrid Wing Body Aircraft (United States)

    Felder, James L.; Brown, Gerald V.; DaeKim, Hyun; Chu, Julio


    The performance of the N3-X, a 300 passenger hybrid wing body (HWB) aircraft with turboelectric distributed propulsion (TeDP), has been analyzed to see if it can meet the 70% fuel burn reduction goal of the NASA Subsonic Fixed Wing project for N+3 generation aircraft. The TeDP system utilizes superconducting electric generators, motors and transmission lines to allow the power producing and thrust producing portions of the system to be widely separated. It also allows a small number of large turboshaft engines to drive any number of propulsors. On the N3-X these new degrees of freedom were used to (1) place two large turboshaft engines driving generators in freestream conditions to maximize thermal efficiency and (2) to embed a broad continuous array of 15 motor driven propulsors on the upper surface of the aircraft near the trailing edge. That location maximizes the amount of the boundary layer ingested and thus maximizes propulsive efficiency. The Boeing B777-200LR flying 7500 nm (13890 km) with a cruise speed of Mach 0.84 and an 118100 lb payload was selected as the reference aircraft and mission for this study. In order to distinguish between improvements due to technology and aircraft configuration changes from those due to the propulsion configuration changes, an intermediate configuration was included in this study. In this configuration a pylon mounted, ultra high bypass (UHB) geared turbofan engine with identical propulsion technology was integrated into the same hybrid wing body airframe. That aircraft achieved a 52% reduction in mission fuel burn relative to the reference aircraft. The N3-X was able to achieve a reduction of 70% and 72% (depending on the cooling system) relative to the reference aircraft. The additional 18% - 20% reduction in the mission fuel burn can therefore be attributed to the additional degrees of freedom in the propulsion system configuration afforded by the TeDP system that eliminates nacelle and pylon drag, maximizes boundary

  11. Nesting of Great Cormorants (Phalacrocorax carbo on man-made structures in Ukraine

    Directory of Open Access Journals (Sweden)

    A. I. Sidorenko


    Full Text Available In Ukraine the Great Cormorant (Phalacrocorax carbo Linnaeus, 1758 uses a rather wide range of habitats for nesting: islands, trees and shrubs, reedbeds and a variety of man-made structures. In general, the strategy of nesting on man-made structures is uncommon both in Ukraine and Europe, and Cormorantsdo this only in the absence of other sites suitable for nesting. Special research onCormorant colonies on technogenic constructions was carried out during the field expeditions by the Research Institute of Biodiversity of Terrestrial and Aquatic Ecosystems of Ukraine in 2002–2003 and 2012–2016. Besides this, we used retrospective and current data from the literature and Internet resources. Most of the field work was carried out by making surveys by boat and on foot. As a result, we found 8 Cormorant colonies on technogenic constructions in Ukraine: gas platforms in the Sea of Azov (near the village Strilkove, Henichesk district of Kherson region; sunken ships – targets for bombing training near the Arabat Spit (these are also known as «ship islands»; electricity pylons of the high-voltage Enerhodar Dnipro Power Line where it crosses the Kakhovka Reservoir; the dock in Yahorlyk Bayk, used in the past as a target for bombing training bombing; artificial island-platforms on Lake Chernine (Kinburn Peninsula; an artificial island on the Sasyk Lagoon (Odessa region; artificial islands, made as navigation markers on the Kremenchuk and Kiev reservoirs. The study found that in most cases the accompanying species was the CaspianGull (Larus cachinnans Pallas, 1811, which actively destroys the Cormorants’ nests and eats their eggs and chicks. The number of nests in the colonies varied greatly (5–30 nests on the navigation marker islands and ca. 2 000–2 300 on the «ship-islands» and gas platforms. This is due, primarily, to the area of the breeding territory. The research found that fierce territorial competition was observed in most of the

  12. Observations of Red-headed Falcon Falco chicquera (Aves: Falconiformes: Falconidae nest at Keraniganj, Dhaka, Bangladesh, with a focus on post-fledging behavior

    Directory of Open Access Journals (Sweden)

    Mohammod Foysal


    Full Text Available A nest of Red-headed Falcon Falco chicquera was observed in 2009, beginning with the onset of breeding and continuing on to the next breeding of the pair.  The nest was found on 02 March 2009 in an electricity pylon in a sub-urban area at Keraniganj, Dhaka, Bangladesh.  The incubation period was estimated at a minimum of four weeks and the nestling period was 37 days.  Fledglings remained in the nesting area up to four months after fledging.  The female almost exclusively fed the nestlings and fledglings.  The diet of adults, nestlings and fledglings consisted of 72% small birds (sparrow sized and 28% Pipistrellus bats (n = 112.  The diet of fledglings consisted of 61% birds and 39% bats (n= 72; before independence mainly birds and after independence mainly bats.  Parents delivered prey to fledglings up to 39 days after fledging (i.e., post-fledging dependence period was 39 days.  The fledgling’s flight pattern was distinguishable from the adults nearly two months after fledging.  The fledgling’s call reminiscent of a begging call was recorded up to 75 days after fledging. Food competition was observed among the fledglings; when one of the fledglings snatched prey from a parent, the other siblings tried to pilfer it.  The parents had resumed breeding eight months after the fledging stage of their offspring. 

  13. Mechanical rebar splicing

    Directory of Open Access Journals (Sweden)

    Milosavljević Branko


    Full Text Available Different mechanical rebar splicing systems are presented, and design situations where mechanical splicing has advantage over reinforcement splicing by overlapping and welding are defined in this paper. New international standards for testing and proof of systems for mechanical rebar splicing quality are considered. Mechanical splicing system for rebar and bolt connection, usable in steel and reinforced concrete structural elements connections, is presented in this paper. There are only few examples of mechanical rebar splicing in our country. The most significant one - the pylon and beam connection at Ada Bridge in Belgrade is presented in the paper. Intensive development of production and use of mechanical rebar splicing systems, research in this area, as well as the publication of international standards prescribing requirements for quality and procedures for proof of quality, represent very good base for development of the corresponding technical norms in Serbia. The legislation in this area would quicken proof of quality procedures, attest and approval issuing for individual products, leading to wider use of this system in all situations where it is in advantage over the classical reinforcement splicing.

  14. Jewellery from Burials Located in the Southern Part of Bolgar Fortifi ed Settlement (Excavations CLXXIV and CCXIV of 2012 and 2015

    Directory of Open Access Journals (Sweden)

    Rudenko Konstantin A.


    Full Text Available The article presents jewellery from three burials discovered in the course of archaeological works in the southern part of Bolgar fortified settlement (excavations CLXXIV and CCXIV. The major part of the area studied in 2012 and 2015 is occupied by a 14th century cemetery encircling a stone mausoleum. Of particular interest is a complex of silver jewellery discovered inside a silk pouch (? in the filling materials of the pit of burial No. 52/2012 near the eastern pylon of the mausoleum. The complex includes seven plate bracelets decorated with lion's faces, three pins, two pendants in the form of boxes with eyelets for hanging decorated with grains and filigree, and inlays composed of glazed ceramic fragments. In addition, the complex features a pendant made of a silver coin minted by khan Janibek (1341–1357. A unique headdress decorated with round gold rings was discovered in burial No. 89/2012 inside the mausoleum. Two pendant rings made of gold wire were discovered in a child burial No. 16/2015 located west of the mausoleum. The authors conclude that the jewellery was generally produced locally and used by the population of Bolgar town in 14th century.

  15. Rapid determination of radon daughter concentrations

    International Nuclear Information System (INIS)

    Bigu, J.


    A technical evaluation of four radon 222 progeny measuring instruments has been conducted. The evaluation has been carried out under laboratory controlled conditions and at several locations in an underground uranium mine. The laboratory evaluation consisted of a thorough study of the behaviour and performance of the instruments under a wide variety of environmental conditions such as radon 222 gas concentration, radon 222 progeny concentration, temperature, relative humidity, aerosol concentration, and gamma-field exposure. The four instruments tested were: the Pylon WL-1000C, the MDA IWLM-811, the MIMIL IIM, and the EDA WLM-30. The readings of the instruments were compared with a widely accepted radon 222 progeny concentration measuring method, namely, the Thomas-Tsivoglou method. Two variables affected two instruments significantly, namely, under high aerosol concentration conditions, one of the instruments (EDA WLM-30) ceased to operate because of filter loading. The other variable was gamma-field exposure which affected another instrument (MDA-811) adversely. The instruments were rated according to several criteria. The overall best performer was the MIMIL IIM, although other instruments also fared quite well under a variety of experimental conditions

  16. Distal tibial fracture treated by minimally invasive plate osteosynthesis after external fixation Retrospective clinical and radiographic assessment

    Directory of Open Access Journals (Sweden)

    Al. Șerban


    Full Text Available Fractures of the horizontal surface of the distal tibia are known commonly as pylon or plafond fractures, and represent 1-5% of lower extremity fractures, 7-10% of all tibial fractures. The protocol consisted of immediate (within eight to 24 hours open reduction and internal fixation of the fibula, using a fibular plate or one third tubular plate and application of an external fixator spanning the ankle joint. In the second stage, the treatment of proximal and distal tibial fractures with close reduction and MIPPO technique can preserve soft tissue, simplify operative procedure and decrease wound, obtain rigid internal fixation and guarantee early function exercises of ankle joint. In this study we evaluated 22 patients treated in Clinical Emergency Hospital Constanta between April 2012 - July 2013 diagnosed with multifragmentary fractures of the distal tibia. This study evaluates the treatment of complex fractures of distal tibia with locked plate after external fixation. There were 17 males and 5 females of mean age 51,7 years (31-68. The mean follow-up period was 14 weeks. (Ranging from 9-16 weeks. All patients were fully weight bearing at 16 weeks (ranging 9-16 weeks showing radiological union. There were no cases of failures of fixation, or rotational misalignment. No significant complication was observed in our patients. MIPO is an effective method of treatment for distal tibial fractures, reduce surgical trauma and maintain a more biologically favorable environment for fracture healing, reducing risks of infection and nonunion.

  17. Preliminary study of a SAVONIUS rotor and its adaptation to a pumping system using wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Lebchek, Kamel; Outtas, T.; Mesmoudi, K. [Mechanical Engineering Departement, Faculty of Engineering Sciences, University of Batna, Batna (Algeria)


    The Wind energy is an uncertain and discontinuous energy in the time, asking for no primary extraction, it is free and its capture is without serious influence on the climate and doesn't produce none poisonous residues for the atmosphere. The capture of the Wind energy is assured by the wind rotors, and among a big number of variants rotors, those with vertical axis present the advantage of construction simplicity, because they don't require any system of orientation and a simple pylon can serve like support. In this setting, our work consists in a experimental study of a rotor with vertical axis called SAVONIUS and its adaptation to a pumping system using the Wind energy. The experimental study has been achieved in subsonic wind tunnel, after realisation of a model of the SAVONIUS rotor and a special installation of transmission of the energy. The adaptation of the experimental results to a pumping system in the real case, permitted us the determination of the variation of (ıCp) and (ıı) according to the speed of wind and the establishment of a range of debits of the pump according to a range of wind speeds chosen by the meteorological evaluations of Batna region . Key words: Wind energy, SAVONIUS rotor, pumping system , coefficient of strength, transmission of energy.

  18. Active Control of Low-Speed Fan Tonal Noise Using Actuators Mounted in Stator Vanes: Part III Results (United States)

    Sutliff, Daniel L.; Remington, Paul J.; Walker, Bruce E.


    A test program to demonstrate simplification of Active Noise Control (ANC) systems relative to standard techniques was performed on the NASA Glenn Active Noise Control Fan from May through September 2001. The target mode was the m = 2 circumferential mode generated by the rotor-stator interaction at 2BPF. Seven radials (combined inlet and exhaust) were present at this condition. Several different error-sensing strategies were implemented. Integration of the error-sensors with passive treatment was investigated. These were: (i) an in-duct linear axial array, (ii) an induct steering array, (iii) a pylon-mounted array, and (iv) a near-field boom array. The effect of incorporating passive treatment was investigated as well as reducing the actuator count. These simplified systems were compared to a fully ANC specified system. Modal data acquired using the Rotating Rake are presented for a range of corrected fan rpm. Simplified control has been demonstrated to be possible but requires a well-known and dominant mode signature. The documented results here in are part III of a three-part series of reports with the same base title. Part I and II document the control system and error-sensing design and implementation.

  19. Feasibility Study of the Electromagnetic Damper for Cable Structures Using Real-Time Hybrid Simulation. (United States)

    Jung, Ho-Yeon; Kim, In-Ho; Jung, Hyung-Jo


    Cable structure is a major component of long-span bridges, such as cable-stayed and suspension bridges, and it transfers the main loads of bridges to the pylons. As these cable structures are exposed to continuous external loads, such as vehicle and wind loads, vibration control and continuous monitoring of the cable are required. In this study, an electromagnetic (EM) damper was designed and fabricated for vibration control and monitoring of the cable structure. EM dampers, also called regenerative dampers, consist of permanent magnets and coils. The electromagnetic force due to the relative motion between the coil and the permanent magnet can be used to control the vibration of the structure. The electrical energy can be used as a power source for the monitoring system. The effects of the design parameters of the damper were numerically analyzed and the damper was fabricated. The characteristics of the damper were analyzed with various external load changes. Finally, the vibration-control and energy-harvesting performances of the cable structure were evaluated through a hybrid simulation. The vibration-control and energy-harvesting performances for various loads were analyzed and the applicability to the cable structure of the EM damper was evaluated.

  20. Error Analysis of Relative Calibration for RCS Measurement on Ground Plane Range

    Directory of Open Access Journals (Sweden)

    Wu Peng-fei


    Full Text Available Ground plane range is a kind of outdoor Radar Cross Section (RCS test range used for static measurement of full-size or scaled targets. Starting from the characteristics of ground plane range, the impact of environments on targets and calibrators is analyzed during calibration in the RCS measurements. The error of relative calibration produced by the different illumination of target and calibrator is studied. The relative calibration technique used in ground plane range is to place the calibrator on a fixed and auxiliary pylon somewhere between the radar and the target under test. By considering the effect of ground reflection and antenna pattern, the relationship between the magnitude of echoes and the position of calibrator is discussed. According to the different distances between the calibrator and target, the difference between free space and ground plane range is studied and the error of relative calibration is calculated. Numerical simulation results are presented with useful conclusions. The relative calibration error varies with the position of calibrator, frequency and antenna beam width. In most case, set calibrator close to the target may keep the error under control.

  1. Radon measurements and dose estimate of workers in a manganese ore mine. (United States)

    Shahrokhi, Amin; Vigh, Tamás; Németh, Csaba; Csordás, Anita; Kovács, Tibor


    In the new European Basic Safety Standard (EU-BSS), a new reference level for indoor radon concentration in workplaces has recommended that the annual average activity concentration of indoor radon shall not be higher than 300Bqm -3 . This paper describes the radon concentration level in an underground workplace (manganese ore mine) over long time intervals (4 years). Several common radon monitors devices - including NRPB and Raduet (as a passive method based on CR-39), AlphaGUARD PQ 2000Pro, SARAD EQF3220, TESLA and Pylon WLX (as active methods) - were used for continuous radon measurements. The output results were used, first, to comprised the result of each device, based on conditions present in underground mines; Second, to have comprehensive measurements about all factors that cause workers exposure to radiation (each monitoring device specified for a unique measurement). The results indicate that the mine's staff had successful efforts to reach the strict requirement of the new EU-BSS, and the average annual radon activity concentrations during the working hours were below 300Bqm -3 in the investigated period. The paper presents the effective dose calculations; applying different equilibrium factors suggested by the literature and calculated basing on our measurements at the site, concluding that the differences could be about threefold. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. A comparison of models for measurable deterioration: An application to coatings on steel structures

    Energy Technology Data Exchange (ETDEWEB)

    Nicolai, Robin P. [Econometric Institute and Tinbergen Institute, Erasmus University Rotterdam, P.O. Box 1738, NL-3000 DR Rotterdam (Netherlands)]. E-mail:; Dekker, Rommert [Econometric Institute, Erasmus University Rotterdam, P.O. Box 1738, NL-3000 DR Rotterdam (Netherlands); Noortwijk, Jan M. van [HKV Consultants, P.O. Box 2120, NL-8203 AC Lelystad (Netherlands); Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, P.O. Box 5031, NL-2600 GA Delft (Netherlands)


    Steel structures like bridges, tanks and pylons are exposed to outdoor weathering conditions. In order to prevent them from corrosion they are protected by organic coating systems. This paper focuses on modelling the deterioration of the organic coating layer that protects steel structures from corrosion. Only if there is sufficient knowledge of the condition of the coating on these structures, maintenance actions can be done in the most efficient way. Therefore the course of the deterioration of the coating system and its lifetime, which is also of importance for doing maintenance, have to be assessed accurately. In this paper, three different stochastic processes, viz. Brownian motion with non-linear drift, the non-stationary gamma process and a two-stage hit-and-grow physical process, are fitted to two real data sets. In this way we are the first who compare the three stochastic processes empirically on criteria such as goodness-of-fit, computational convenience and ease of implementation. The first data set is based on expert judgement; the second consists of inspection results. In the first case the model parameters are obtained by a least-squares approach, in the second case by the method of maximum likelihood. A meta-analysis is performed on the two-stage hit-and-grow model by means of fitting Brownian motion and gamma process to the outcomes of this model.

  3. A comparison of models for measurable deterioration: An application to coatings on steel structures

    International Nuclear Information System (INIS)

    Nicolai, Robin P.; Dekker, Rommert; Noortwijk, Jan M. van


    Steel structures like bridges, tanks and pylons are exposed to outdoor weathering conditions. In order to prevent them from corrosion they are protected by organic coating systems. This paper focuses on modelling the deterioration of the organic coating layer that protects steel structures from corrosion. Only if there is sufficient knowledge of the condition of the coating on these structures, maintenance actions can be done in the most efficient way. Therefore the course of the deterioration of the coating system and its lifetime, which is also of importance for doing maintenance, have to be assessed accurately. In this paper, three different stochastic processes, viz. Brownian motion with non-linear drift, the non-stationary gamma process and a two-stage hit-and-grow physical process, are fitted to two real data sets. In this way we are the first who compare the three stochastic processes empirically on criteria such as goodness-of-fit, computational convenience and ease of implementation. The first data set is based on expert judgement; the second consists of inspection results. In the first case the model parameters are obtained by a least-squares approach, in the second case by the method of maximum likelihood. A meta-analysis is performed on the two-stage hit-and-grow model by means of fitting Brownian motion and gamma process to the outcomes of this model

  4. Development of a computational environment for the General Curvilinear Ocean Model

    International Nuclear Information System (INIS)

    Thomas, Mary P; Castillo, Jose E


    The General Curvilinear Ocean Model (GCOM) differs significantly from the traditional approach, where the use of Cartesian coordinates forces the model to simulate terrain as a series of steps. GCOM utilizes a full three-dimensional curvilinear transformation, which has been shown to have greater accuracy than similar models and to achieve results more efficiently. The GCOM model has been validated for several types of water bodies, different coastlines and bottom shapes, including the Alarcon Seamount, Southern California Coastal Region, the Valencia Lake in Venezuela, and more recently the Monterey Bay. In this paper, enhancements to the GCOM model and an overview of the computational environment (GCOM-CE) are presented. Model improvements include migration from F77 to F90; approach to a component design; and initial steps towards parallelization of the model. Through the use of the component design, new models are being incorporated including biogeochemical, pollution, and sediment transport. The computational environment is designed to allow various client interactions via secure Web applications (portal, Web services, and Web 2.0 gadgets). Features include building jobs, managing and interacting with long running jobs; managing input and output files; quick visualization of results; publishing of Web services to be used by other systems such as larger climate models. The CE is based mainly on Python tools including a grid-enabled Pylons Web application Framework for Web services, pyWSRF (python-Web Services-Resource Framework), pyGlobus based web services, SciPy, and Google code tools.

  5. Thermally Driven Transport and Relaxation Switching Self-Powered Electromagnetic Energy Conversion. (United States)

    Cao, Maosheng; Wang, Xixi; Cao, Wenqiang; Fang, Xiaoyong; Wen, Bo; Yuan, Jie


    Electromagnetic energy radiation is becoming a "health-killer" of living bodies, especially around industrial transformer substation and electricity pylon. Harvesting, converting, and storing waste energy for recycling are considered the ideal ways to control electromagnetic radiation. However, heat-generation and temperature-rising with performance degradation remain big problems. Herein, graphene-silica xerogel is dissected hierarchically from functions to "genes," thermally driven relaxation and charge transport, experimentally and theoretically, demonstrating a competitive synergy on energy conversion. A generic approach of "material genes sequencing" is proposed, tactfully transforming the negative effects of heat energy to superiority for switching self-powered and self-circulated electromagnetic devices, beneficial for waste energy harvesting, conversion, and storage. Graphene networks with "well-sequencing genes" (w = P c /P p > 0.2) can serve as nanogenerators, thermally promoting electromagnetic wave absorption by 250%, with broadened bandwidth covering the whole investigated frequency. This finding of nonionic energy conversion opens up an unexpected horizon for converting, storing, and reusing waste electromagnetic energy, providing the most promising way for governing electromagnetic pollution with self-powered and self-circulated electromagnetic devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Calibration factor determination for solid nuclear track detectors CR-39 type exposed to Rn-222

    International Nuclear Information System (INIS)

    Cazula, Camila Dias; Campos, Marcia Pires de; Mazzilli, Barbara Paci


    In the detection method with solid nuclear track detector, when a heavy particle rests on the detector surface, causes a breakdown in their molecular structure forming a trace. One of the typical applications of these detectors is the measurement of the concentration of Rn -222 in air, a noble radioactive gas, part of the U-238 series, emitting alpha particles and important in epidemiological studies to protect individuals from natural radiation. To determine the concentration of Rn -222 in the air in a room is necessary to know the density of lines (traces / cm 2 ) on the detector surface, the exposure time and the calibration factor. The determination of the calibration factor for CR-39 detectors was taken from the exposure of these to a known concentration of Rn-222. Therefore, the detectors were placed inside a cell of Lucas adapted and subsequently exposed to a concentration of Rn-222 15 kBq / m 3 , by means of the apparatus RN-150 Pylon Electronics Incorporation, which has a source of Ra-226 and releases known concentrations of Rn-222. Six calibration factor determinations were performed, the average value obtained was 0.0534 ±0.0021 (traces / cm 2 per Bq / m 3 day). The results are consistent with literature values for the same type of detector and showed good reproducibility

  7. Radon measurements with a PIN photodiode

    International Nuclear Information System (INIS)

    Martin-Martin, A.; Gutierrez-Villanueva, J.L.; Munoz, J.M.; Garcia-Talavera, M.; Adamiec, G.; Iniguez, M.P.


    Silicon photodiodes are well suited to detect alphas coming from different sources as neutron reactions or radon daughters. In this work a radon in air detecting device, using an 18x18 mm silicon PIN photodiode is studied. The ionized airborne decay products formed during radon diffusion were focused by an accelerating high voltage to the PIN surface. Several conducting rings were disposed inside a cylindrical PVC vessel in such a way that they reproduced the electric field created by a punctual charge located behind PIN position. Alpha spectra coming from the neutral and ionized species deposited on the PIN surface, dominated by 218 Po and 214 Po progeny peaks, were recorded for varying conditions. Those include radon concentration from a Pylon source, high voltage (thousands of volts) and PIN inverse bias voltage. Different parameters such as temperature and humidity were also registered during data acquisition. The increase in the particle collection efficiency with respect to zero electric field was compared with the corresponding to a parallel plates configuration. A discussion is made in terms of the most appropriate voltages for different radon concentrations

  8. Aerodynamic problems of cable-stayed bridges spanning over one thousand meters

    Institute of Scientific and Technical Information of China (English)

    Chen Airong; Ma Rujin; Wang Dalei


    Tbe elongating of cable-stayed bridge brings a series of aerodynamic problems. First of all, geometric nonlin-ear effect of extreme long cable is much more significant for cable-stayed bridge spanning over one thousand meters. Lat-eral static wind load will generate additional displacement of long cables, which causes the decrease of supporting rigidi-ty of the whole bridge and the change of dynamic properties. Wind load, being the controlling load in the design of ca-hie-stayed bridge, is a critical problem and needs to be solved. Meanwhile, research on suitable system between pylon and deck indicates fixed-fixed connection system is an effective way for improvement performance of cable-stayed bridges under longitudinal wind load. In order to obtain aerodynamic parameters of cable-stayed bridge spanning over one thou-sand meters, identification method for flutter derivatives of full bridge aero-elastic model is developed in this paper. Furthermore, vortex induced vibration and Reynolds number effect are detailed discussed.

  9. Design Optimization and Development of Tubular Isogrid Composites Tubes for Lower Limb Prosthesis (United States)

    Junqueira, Diego Morais; Gomes, Guilherme Ferreira; Silveira, Márcio Eduardo; Ancelotti, Antonio Carlos


    From the beginnings of humanity, natural or unnatural misfortunes such as illnesses, wars, automobile accidents cause loss of body limbs like teeth, arms, legs, etc. The solution found for the replacement of these missing limbs is in the use of prostheses. Lower limbs tubes or pylons are prosthetics components that are claimed to support loads during walking and other daily tasks activities. Commonly, prosthetic tubes are manufactured using metal materials such as stainless steel, aluminum and titanium. The mass of these tubes is generally high compared to tubes made of carbon fiber reinforced polymer matrix (CFRP) composite. Therefore, this work has the objective of design, manufacturing and analyzing the feasibility of a new tube concept, made of composite material, which makes use of lattice structure and inner layer. Until the present moment, lower limb prosthesis tubes using lattice structure and ineer layer have never been studied and/or tested to date. It can be stated that the tube of rigid ribs with inner layer and angle of 40° is more efficient than those of 26° and 30°. The proposed design allows a structural weight reduction in high performance prostheses from 120 g to 40 g.

  10. Geometric nonlinear analysis of self-anchored cable-stayed suspension bridges. (United States)

    Hui-Li, Wang; Yan-Bin, Tan; Si-Feng, Qin; Zhe, Zhang


    Geometric nonlinearity of self-anchored cable-stayed suspension bridges is studied in this paper. The repercussion of shrinkage and creep of concrete, rise-to-span ratio, and girder camber on the system is discussed. A self-anchored cable-stayed suspension bridge with a main span of 800 m is analyzed with linear theory, second-order theory, and nonlinear theory, respectively. In the condition of various rise-to-span ratios and girder cambers, the moments and displacements of both the girder and the pylon under live load are acquired. Based on the results it is derived that the second-order theory can be adopted to analyze a self-anchored cable-stayed suspension bridge with a main span of 800 m, and the error is less than 6%. The shrinkage and creep of concrete impose a conspicuous impact on the structure. And it outmatches suspension bridges for system stiffness. As the rise-to-span ratio increases, the axial forces of the main cable and the girder decline. The system stiffness rises with the girder camber being employed.

  11. Thermoelectric Energy Harvesting Using Phase Change Materials (PCMs) in High Temperature Environments in Aircraft (United States)

    Elefsiniotis, A.; Becker, Th.; Schmid, U.


    Wireless, energy-autonomous structural health-monitoring systems in aircraft have the potential of reducing total maintenance costs. Thermoelectric energy harvesting, which seems the best choice for creating truly autonomous health monitoring sensors, is the principle behind converting waste heat to useful electrical energy through the use of thermoelectric generators. To enhance the temperature difference across the two sides of a thermoelectric generator, i.e. increasing heat flux and energy production, a phase change material acting as thermal mass is attached on one side of the thermoelectric generators while the other side is placed on the aircraft structure. The application area under investigation for this paper is the pylon aft fairing, located near the engine of an aircraft, with temperatures reaching on the inside up to 350 °C. Given these harsh operational conditions, the performance of a device, containing erythritol as a phase change material, is evaluated. The harvested energy reaching values up to 81.4 J can be regulated by a power management module capable of storing the excess energy and recovering it from the medium powering a sensor node and a wireless transceiver.

  12. Seismic response of cable stayed bridges under multi support excitation

    Directory of Open Access Journals (Sweden)

    Mahmoud Reza ُُShiravand


    Full Text Available In this Study, the seismic response of cable stayed bridges have been evaluated under multi-support excitations. There are three sources that cause the earthquake wave characteristics change during its propagation path. Local site effect, loss of coherency and wave passage effect are three sources of spatial variation of seismic ground motions. In long span structures, such as cable supported bridges, this phenomenon is more evident and traditional analyzing (uniform excitation may not be valid and be conservative. Thus, it is necessary to investigate the response of cable stayed bridges under non-uniform excitations. For this purpose, the non-uniform time histories were artificially generated using Kriging method based on a set of known time history in the west support of bridge. Nonlinear time history analysis was performed and cables axial force, deck moment, pylons moment and finally drift ratio of bridge have been examined in order to investigate how non-uniform excitation change the seismic response of bridge compared with uniform excitations. Results show non-uniform excitation in some bridge components increase responses and decreases in the others. In non-uniform excitation, although total time history energy is lesser than uniform excitation, it can significantly change the distribution of the forces and makes differential displacement between cables supports and increase the possibility of failure.

  13. [Lead intoxication in a group of workers in Germany]. (United States)

    Willi, R F; Felgenhauer, N; Eyer, F; Buters, J T; Zilker, T


    Seventeen East-European workers with a suspected lead-intoxication presented themselves to the Department of Toxicology. All of them had worked on the renovation of pylons of a high-tension line. The old paint, known to contain lead was removed with needle descalers. The patients had blood lead concentrations between 325 and 1124 microg/l, but no specific symptoms. The workers neglected the protective measures at their working-place. 12 of 17 workers had lead-concentrations above 400 microg/l (Reference lead-concentration above 700 microg/l were treated with the chelating agent meso-2,3-dimercaptosuccinic acid (DMSA) 3 x 200 mg/d for nine days. The patients with lead concentrations between 400 and 700 microg/l were treated which DMSA 3 x 100 mg/d. After the DMSA-treatment the lead-concentrations had dropped (p lead concentration in their blood due to occupational exposure. The high blood lead levels showed that the workers had not been protected adequately. This examplifies that occupational lead exposure still occurs, also in Germany. By patients with unspecific symptoms connected with lead exposure a biomonitoring for lead is necessary.

  14. Far-Field Acoustic Power Level and Performance Analyses of F31/A31 Open Rotor Model at Simulated Scaled Takeoff, Nominal Takeoff, and Approach Conditions: Technical Report I (United States)

    Sree, Dave


    Far-field acoustic power level and performance analyses of open rotor model F31/A31 have been performed to determine its noise characteristics at simulated scaled takeoff, nominal takeoff, and approach flight conditions. The nonproprietary parts of the data obtained from experiments in 9- by 15-Foot Low-Speed Wind Tunnel (9?15 LSWT) tests were provided by NASA Glenn Research Center to perform the analyses. The tone and broadband noise components have been separated from raw test data by using a new data analysis tool. Results in terms of sound pressure levels, acoustic power levels, and their variations with rotor speed, angle of attack, thrust, and input shaft power have been presented and discussed. The effect of an upstream pylon on the noise levels of the model has been addressed. Empirical equations relating model's acoustic power level, thrust, and input shaft power have been developed. The far-field acoustic efficiency of the model is also determined for various simulated flight conditions. It is intended that the results presented in this work will serve as a database for comparison and improvement of other open rotor blade designs and also for validating open rotor noise prediction codes.

  15. An animal model to evaluate skin-implant-bone integration and gait with a prosthesis directly attached to the residual limb. (United States)

    Farrell, Brad J; Prilutsky, Boris I; Kistenberg, Robert S; Dalton, John F; Pitkin, Mark


    Despite the number of advantages of bone-anchored prostheses, their use in patients is limited due to the lack of complete skin-implant integration. The objective of the present study was to develop an animal model that would permit both detailed investigations of gait with a bone-anchored limb prosthesis and histological analysis of the skin-implant-bone interface after physiological loading of the implant during standing and walking. Full-body mechanics of walking in two cats were recorded and analyzed before and after implantation of a percutaneous porous titanium pylon into the right tibia and attachment of a prosthesis. The rehabilitation procedures included initial limb casting, progressively increasing loading on the implant, and standing and locomotor training. Detailed histological analysis of bone and skin ingrowth into implant was performed at the end of the study. The two animals adopted the bone-anchored prosthesis for standing and locomotion, although loads on the prosthetic limb during walking decreased by 22% and 62%, respectively, 4months after implantation. The animals shifted body weight to the contralateral side and increased propulsion forces by the contralateral hindlimb. Histological analysis of the limb implants demonstrated bone and skin ingrowth. The developed animal model to study prosthetic gait and tissue integration with the implant demonstrated that porous titanium implants may permit bone and skin integration and prosthetic gait with a bone-anchored prosthesis. Future studies with this model will help optimize the implant and prosthesis properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Vulture rescue and rehabilitation in South Africa: An urban perspective

    Directory of Open Access Journals (Sweden)

    V. Naidoo


    Full Text Available SouthAfrica is home to 9 vulture species, of which 7 are endangered. While the cause of the population declines remains largely speculative, a vast amount of effort has been dedicated towards the protection of populations by ensuring sustainable and safe food sources for the various colonies. Limited focus was placed in the past on efforts related to the rescue and/or rehabilitation (R&R of injured birds and the release of these birds back into the wild. This paper provides an overview of the causes, the impact and success of 3 organisations involved in R&R efforts of vultures in the Magaliesberg mountain range and surrounding areas over a period of 10 years. Study material included 162 Cape griffon (CGV and 38 African white-backed (AWBV vultures. Datasets include the number, sex and age of birds received, the reason the vultures were brought in for R&R, surgical interventions performed and outcomes of rescue efforts. The CGV dominated the rehabilitation attempts. Results further show that a large number of apparently healthy birds were presented for veterinary treatment. The R&R data clearly indicate that the major cause of injuries was birds colliding with overhead pylons, as a high number of soft tissue and skeletal injuries were observed. The study also shows that successful releases of rescued birds are possible. It is concluded that urbanisation has had a major negative impact on vultures around the Magaliesberg mountain range.

  17. Mechanical behavior and modelisation of Ti-6Al-4V titanium sheet under hot stamping conditions (United States)

    Sirvin, Q.; Velay, V.; Bonnaire, R.; Penazzi, L.


    The Ti-6Al-4V titanium alloy is widely used for the manufacture of aeronautical and automotive parts (solid parts). In aeronautics, this alloy is employed for its excellent mechanical behavior associated with low density, outstanding corrosion resistance and good mechanical properties up to 600°C. It is especially used for the manufacture of fuselage frames, on the pylon for carrying out the primary structure (machining forged blocks) and the secondary structure in sheet form. In this last case, the sheet metal forming can be done through various methods: at room temperature by drawing operation, at very high temperature (≃900°C) by superplastic forming (SPF) and at intermediate temperature (≥750°C) by hot forming (HF). In order to reduce production costs and environmental troubles, the cycle times reduction associated with a decrease of temperature levels are relevant. This study focuses on the behavior modelling of Ti-6Al-4V alloy at temperatures above room temperature to obtained greater formability and below SPF condition to reduce tools workshop and energy costs. The displacement field measurement obtained by Digital Image Correlation (DIC) is based on innovative surface preparation pattern adapted to high temperature exposures. Different material parameters are identified to define a model able to predict the mechanical behavior of Ti-6Al-4V alloy under hot stamping conditions. The hardening plastic model identified is introduced in FEM to simulate an omega shape forming operation.

  18. A New Position Measurement System Using a Motion-Capture Camera for Wind Tunnel Tests

    Directory of Open Access Journals (Sweden)

    Yousok Kim


    Full Text Available Considering the characteristics of wind tunnel tests, a position measurement system that can minimize the effects on the flow of simulated wind must be established. In this study, a motion-capture camera was used to measure the displacement responses of structures in a wind tunnel test, and the applicability of the system was tested. A motion-capture system (MCS could output 3D coordinates using two-dimensional image coordinates obtained from the camera. Furthermore, this remote sensing system had some flexibility regarding lab installation because of its ability to measure at relatively long distances from the target structures. In this study, we performed wind tunnel tests on a pylon specimen and compared the measured responses of the MCS with the displacements measured with a laser displacement sensor (LDS. The results of the comparison revealed that the time-history displacement measurements from the MCS slightly exceeded those of the LDS. In addition, we confirmed the measuring reliability of the MCS by identifying the dynamic properties (natural frequency, damping ratio, and mode shape of the test specimen using system identification methods (frequency domain decomposition, FDD. By comparing the mode shape obtained using the aforementioned methods with that obtained using the LDS, we also confirmed that the MCS could construct a more accurate mode shape (bending-deflection mode shape with the 3D measurements.

  19. Application study on the first cable-stayed bridge with CFRP cables in China

    Directory of Open Access Journals (Sweden)

    Kuihua Mei


    Full Text Available In order to push forward the development of CFRP cable-stayed bridge and accumulate experiences, the study on the application of the first cable-stayed bridge with CFRP cables in China was carried out. The design essentials of main components of the bridge were introduced and its integral performances, including static properties, dynamic properties and seismic response were analyzed using finite element method. A new bond-type anchorage was developed and the processes of fabricating and installing CFRP cables were elaborated. Based on the results of construction simulation, a tension scheme for bridge was propound. During constructing, the stresses and displacement of girder and pylon, as well as the forces and stresses of cables, were tested. The results indicate that all sections of the bridge could meet the requirements of the ultimate bearing capacity and normal service; the performance of the anchorage is good and the stresses in each cable system are similar; the tested values accord well with the calculated values. Further, creep deformation of the resin in anchorages under service load is not obvious. All these results demonstrate that the first application of CFRP cables in the cable-stayed bridge in China is successful.

  20. The prediction of noise and installation effects of high-subsonic dual-stream jets in flight (United States)

    Saxena, Swati

    Both military and civil aircraft in service generate high levels of noise. One of the major contributors to this noise generated from the aircraft is the jet engine exhaust. This makes the study of jet noise and methods to reduce jet noise an active research area with the aim of designing quieter military and commercial aircraft. The current stringent aircraft noise regulations imposed by the Federal Aviation Administration (FAA) and other international agencies, have further raised the need to perform accurate jet noise calculations for more reliable estimation of the jet noise sources. The main aim of the present research is to perform jet noise simulations of single and dual-stream jets with engineering accuracy and assess forward flight effects on the jet noise. Installation effects such as caused by the pylon are also studied using a simplified pylon nozzle configuration. Due to advances in computational power, it has become possible to perform turbulent flow simulations of high speed jets, which leads to more accurate noise predictions. In the present research, a hybrid unsteady RANS-LES parallel multi-block structured grid solver called EAGLEJet is written to perform the nozzle flow calculations. The far-field noise calculation is performed using solutions to the Ffowcs Williams and Hawkings equation. The present calculations use meshes with 5 to 11 million grid points and require about three weeks of computing time with about 100 processors. A baseline single stream convergent nozzle and a dual-stream coaxial convergent nozzle are used for the flow and noise analysis. Calculations for the convergent nozzle are performed at a high subsonic jet Mach number of Mj = 0.9, which is similar to the operating conditions for commercial aircraft engines. A parallel flow gives the flight effect, which is simulated with a co-flow Mach number, Mcf varying from 0.0 to 0.28. The grid resolution effects, statistical properties of the turbulence and the heated jet effects

  1. Performance analysis of cooling stabilizing burners for different stress boiler unit


    Fialko, N. M.; Prokopov, V. H.; Alyosha, S. A.; Sherenkovskyy, Y.; Meranova, N. A.; Polozenko, N. P.; Malecki, A. E.


    The numerical research data of the jet–stabilization burners cooling system of with different baffles are presented of the jet airflow of inside end surface by flat and round jets with different width pylon is presented. The analysis of the load influence on the boiler efficiency cooling system is carried out. Наведено дані числових досліджень систем охолодження струменево- стабілізаторних пальникових пристроїв за схемою із струменевим обдувом внутрішньої торцевої ...

  2. The evolution of whole field optical diagnostics for external transonic testing (United States)

    Fry, K. A.; Bryanston-Cross, P.


    The diagnostic use of quantitative laser flow visualization techniques has increased rapidly over recent years. The limitations imposed by conventional single point techniques such as laser Doppler anemometry are addressed and how they have been overcome by the development of a new family of whole field measurement techniques is demonstrated. In particular near instantaneous whole field velocity data was obtained in a relatively hostile, industrial 2.74 m x 2.44 m transonic wind tunnel (TWT) at the Aircraft Research Association (ARA). The techniques were evaluated for their suitability for making quantitative measurements in the wing/pylon region of a model wing and engine combination. Three optical diagnostic techniques were successfully developed within the context of the ARA facility. The first technique, laser light sheet (LLS), combines the operation of a pulse laser and video capture system to provide a 'real time' visualization of the flow, whereas a second pulse laser technique, Particle Image Velocimetry (PIV) can be used to make specific quantitative whole field instantaneous velocity measurements. The third method, holography, was used to produce a stored three dimensional visualization of the unsteady and shock wave features of the transonic flow in the gully region. A description is made of their installation and operation, and examples are presented of current test results.

  3. Seismic Fragility Assessment of an Isolated Multipylon Cable-Stayed Bridge Using Shaking Table Tests

    Directory of Open Access Journals (Sweden)

    Yutao Pang


    Full Text Available In recent decades, cable-stayed bridges have been widely built around the world due to the appealing aesthetics and efficient and fast mode of construction. Numerous studies have concluded that the cable-stayed bridges are sensitive to earthquakes because they possess low damping characteristics and high flexibility. Moreover, cable-stayed bridges need to warrant operability especially in the moderate-to-severe earthquakes. The provisions implemented in the seismic codes allow obtaining adequate seismic performance for the cable-stayed bridge components; nevertheless, they do not provide definite yet reliable rules to protect the bridge. To date, very few experimental tests have been carried out on the seismic fragility analysis of cable-stayed bridges which is the basis of performance-based analyses. The present paper is aimed at proposing a method to derive the seismic fragility curves of multipylon cable-stayed bridge through shake table tests. Toward this aim, a 1/20 scale three-dimensional model of a 22.5 m cable-stayed bridge in China is constructed and tested dynamically by using the shaking table facility of Tongji University. The cable-stayed bridge contains three pylons and one side pier. The outcomes of the comprehensive shaking table tests carried out on cable-stayed bridge have been utilized to derive fragility curves based on a systemic approach.

  4. Evaluation of aerodynamic stability and a trial study of construction-accuracy control by daytime measurement of Meiko West Bridge; Meiko Nishi Ohashi no taifusei kento to chukan keisoku kekka wo mochiita kasetsu seido kanri no shiko

    Energy Technology Data Exchange (ETDEWEB)

    Morimoto, C.; Shimodoi, H.; Isoe, A.; Sakai, Y.; Ochiai, M.; Watabe, T.; Ebihara, R. [Kawasaki Heavy Industries, Ltd., Kobe (Japan)


    The new Meiko West Bridge was constructed very closely to the phase I line bridge which have been already in a service from 1985, and the distance of this world unique parallel cable-stayed bridges is 50m. The length, span and pylon height of these bridges are identical. By conducting wind tunnel experiments considering the aerodynamic interference of the close parallel bridges, the aerodynamic stability of the bridge had been confirmed during construction as well as complete state. After the construction was completed, the important wind characteristics of the parallel cable-stayed bridges were obtained from the site observation. Regarding cable vibrations, a common problem with cable-stayed bridges, a suitable vibration suppression method was applied based on the site observation. In general, the construction-accuracy control is performed by doing measurement at night However, to study the possibility of the accuracy-control by daytime measurement the measurement was conducted not only at night but also in the daytime. (author)

  5. A numerical study on the structural integrity of self-anchored cable-stayed suspension bridges

    Directory of Open Access Journals (Sweden)

    Paolo Lonetti


    Full Text Available A generalized numerical model for predicting the structural integrity of self-anchored cable-stayed suspension bridges considering both geometric and material nonlinearities is proposed. The bridge is modeled by means of a 3D finite element approach based on a refined displacement-type finite element approximation, in which geometrical nonlinearities are assumed in all components of the structure. Moreover, nonlinearities produced by inelastic material and second order effects in the displacements are considered for girder and pylon elements, which combine gradual yielding theory with CRC tangent modulus concept. In addition, for the elements of the suspension system, i.e. stays, hangers and main cable, a finite plasticity theory is adopted to fully evaluate both geometric and material nonlinearities. In this framework, the influence of geometric and material nonlinearities on the collapse bridge behavior is investigated, by means of a comparative study, which identifies the effects produced on the ultimate bridge behavior of several sources of bridge nonlinearities involved in the bridge components. Results are developed with the purpose to evaluate numerically the influence of the material and geometric characteristics of self-anchored cable-stayed suspension bridges with respect also to conventional bridge based on cablestayed or suspension schemes

  6. Feasibility Study of the Electromagnetic Damper for Cable Structures Using Real-Time Hybrid Simulation

    Directory of Open Access Journals (Sweden)

    Ho-Yeon Jung


    Full Text Available Cable structure is a major component of long-span bridges, such as cable-stayed and suspension bridges, and it transfers the main loads of bridges to the pylons. As these cable structures are exposed to continuous external loads, such as vehicle and wind loads, vibration control and continuous monitoring of the cable are required. In this study, an electromagnetic (EM damper was designed and fabricated for vibration control and monitoring of the cable structure. EM dampers, also called regenerative dampers, consist of permanent magnets and coils. The electromagnetic force due to the relative motion between the coil and the permanent magnet can be used to control the vibration of the structure. The electrical energy can be used as a power source for the monitoring system. The effects of the design parameters of the damper were numerically analyzed and the damper was fabricated. The characteristics of the damper were analyzed with various external load changes. Finally, the vibration-control and energy-harvesting performances of the cable structure were evaluated through a hybrid simulation. The vibration-control and energy-harvesting performances for various loads were analyzed and the applicability to the cable structure of the EM damper was evaluated.

  7. Dynamic Analysis of Cable-Stayed Bridges Affected by Accidental Failure Mechanisms under Moving Loads

    Directory of Open Access Journals (Sweden)

    Fabrizio Greco


    Full Text Available The dynamic behavior of cable-stayed bridges subjected to moving loads and affected by an accidental failure in the cable suspension system is investigated. The main aim of the paper is to quantify, numerically, the dynamic amplification factors of typical kinematic and stress design variables, by means of a parametric study developed in terms of the structural characteristics of the bridge components. The bridge formulation is developed by using a geometric nonlinear formulation, in which the effects of local vibrations of the stays and of large displacements in the girder and the pylons are taken into account. Explicit time dependent damage laws, reproducing the failure mechanism in the cable system, are considered to investigate the influence of the failure mode characteristics on the dynamic bridge behavior. The analysis focuses attention on the influence of the inertial characteristics of the moving loads, by accounting coupling effects arising from the interaction between girder and moving system. Sensitivity analyses of typical design bridge variables are proposed. In particular, the effects produced by the moving system characteristics, the tower typologies, and the failure mode characteristics involved in the cable system are investigated by means of comparisons between damaged and undamaged bridge configurations.

  8. Design and construction of superstructure in prestressed concrete cable-stayed bridge. ; Aomori Bay Bridge. PC shachokyo jobuko no sekkei to seko. ; Aomori Bay Bridge

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, T.; Fujimori, S.; Oba, M.; Tsuyoshi, T. (East Japan Railway Co., Tokyo (Japan))


    Aomori Bay Bridge is a 1,219m long elevated bridge, a part of No.2 Bay Highway of 1,993m in total length crossing over Aomori railway station which was planned in ordecr to integrate the port facilities of Aomori Harbor and expedite cargo traffic smoothly. Of this Bay Bridge, its main bridge portion crossing over Aomori railway station and the sea area was planned as a continuous prestressed concrete cable-stayed bridge of 498m in total length and consisting of three portions including the central portion in which the main span between the central bridge piers was 240m. It is scheduled to open in the summer of 1992. With regard to the design of this bridge, special care for the view of the bridge has been taken covering from the structure style to the accessories. For this bridge, a large scale underground continuous wall solid base with a box-shaped section consisting of 6 chambers was adopted for the base of a main tower. It has the cantilever suspension structure of the wide girder with the inverted Y-shaped pylons. For its stav cable, was adopted a large capacity stay cable with standard tensile strength of 1,942 fabricated on the site and for its covering tube, a FRP tube was adopted. In this article, the construction of the main girder and stay cables, and the construction control during their installation by projection are reported. 7 refs., 14 figs., 9 tabs.

  9. Structural Behavior of a Long-Span Partially Earth-Anchored Cable-Stayed Bridge during Installation of a Key Segment by Thermal Prestressing

    Directory of Open Access Journals (Sweden)

    Sang-Hyo Kim


    Full Text Available This study investigated structural behavior of long-span partially earth-anchored cable-stayed bridges with a main span length of 810 m that use a new key segment closing method based on a thermal prestressing technique. A detailed construction sequence analysis matched with the free cantilever method (FCM was performed using a three-dimensional finite element (FE model of a partially earth-anchored cable-stayed bridge. The new method offers an effective way of connecting key segments by avoiding large movements resulting from the removal of the longitudinal restraint owing to the asymmetry of axial forces in the girders near the pylons. The new method develops new member forces through the process of heating the cantilever system before installing the key segment and cooling the system continuously after installing key segments. The resulting forces developed by the thermal process enhance the structural behavior of partially earth-anchored cable-stayed bridges owing to decreased axial forces in the girders.

  10. Geometric Nonlinear Analysis of Self-Anchored Cable-Stayed Suspension Bridges

    Directory of Open Access Journals (Sweden)

    Wang Hui-Li


    Full Text Available Geometric nonlinearity of self-anchored cable-stayed suspension bridges is studied in this paper. The repercussion of shrinkage and creep of concrete, rise-to-span ratio, and girder camber on the system is discussed. A self-anchored cable-stayed suspension bridge with a main span of 800 m is analyzed with linear theory, second-order theory, and nonlinear theory, respectively. In the condition of various rise-to-span ratios and girder cambers, the moments and displacements of both the girder and the pylon under live load are acquired. Based on the results it is derived that the second-order theory can be adopted to analyze a self-anchored cable-stayed suspension bridge with a main span of 800 m, and the error is less than 6%. The shrinkage and creep of concrete impose a conspicuous impact on the structure. And it outmatches suspension bridges for system stiffness. As the rise-to-span ratio increases, the axial forces of the main cable and the girder decline. The system stiffness rises with the girder camber being employed.

  11. Turboelectric Distributed Propulsion Engine Cycle Analysis for Hybrid-Wing-Body Aircraft (United States)

    Felder, James L.; Kim, Hyun Dae; Brown, Gerald V.


    possibilities. The Boeing N2 hybrid-wing-body (HWB) is used as a baseline aircraft for this study. The two pylon mounted conventional turbofans are replaced by two wing-tip mounted turboshaft engines, each driving a superconducting generator. Both generators feed a common electrical bus which distributes power to an array of superconducting motor-driven fans in a continuous nacelle centered along the trailing edge of the upper surface of the wing-body. A key finding was that traditional inlet performance methodology has to be modified when most of the air entering the inlet is boundary layer air. A very thorough and detailed propulsion/airframe integration (PAI) analysis is required at the very beginning of the design process since embedded engine inlet performance must be based on conditions at the inlet lip rather than freestream conditions. Examination of a range of fan pressure ratios yielded a minimum Thrust-specific-fuel-consumption (TSFC) at the aerodynamic design point of the vehicle (31,000 ft /Mach 0.8) between 1.3 and 1.35 FPR. We deduced that this was due to the higher pressure losses prior to the fan inlet as well as higher losses in the 2-D inlets and nozzles. This FPR is likely to be higher than the FPR that yields a minimum TSFC in a pylon mounted engine. 1

  12. Thin tailored composite wing for civil tiltrotor (United States)

    Rais-Rohani, Masoud


    The tiltrotor aircraft is a flight vehicle which combines the efficient low speed (i.e., take-off, landing, and hover) characteristics of a helicopter with the efficient cruise speed of a turboprop airplane. A well-known example of such vehicle is the Bell-Boeing V-22 Osprey. The high cruise speed and range constraints placed on the civil tiltrotor require a relatively thin wing to increase the drag-divergence Mach number which translates into lower compressibility drag. It is required to reduce the wing maximum thickness-to-chord ratio t/c from 23% (i.e., V-22 wing) to 18%. While a reduction in wing thickness results in improved aerodynamic efficiency, it has an adverse effect on the wing structure and it tends to reduce structural stiffness. If ignored, the reduction in wing stiffness leads to susceptibility to aeroelastic and dynamic instabilities which may consequently cause a catastrophic failure. By taking advantage of the directional stiffness characteristics of composite materials the wing structure may be tailored to have the necessary stiffness, at a lower thickness, while keeping the weight low. The goal of this study is to design a wing structure for minimum weight subject to structural, dynamic and aeroelastic constraints. The structural constraints are in terms of strength and buckling allowables. The dynamic constraints are in terms of wing natural frequencies in vertical and horizontal bending and torsion. The aeroelastic constraints are in terms of frequency placement of the wing structure relative to those of the rotor system. The wing-rotor-pylon aeroelastic and dynamic interactions are limited in this design study by holding the cruise speed, rotor-pylon system, and wing geometric attributes fixed. To assure that the wing-rotor stability margins are maintained a more rigorous analysis based on a detailed model of the rotor system will need to ensue following the design study. The skin-stringer-rib type architecture is used for the wing

  13. Solving Man-Induced Large-Scale Conservation Problems: The Spanish Imperial Eagle and Power Lines (United States)

    López-López, Pascual; Ferrer, Miguel; Madero, Agustín; Casado, Eva; McGrady, Michael


    Background Man-induced mortality of birds caused by electrocution with poorly-designed pylons and power lines has been reported to be an important mortality factor that could become a major cause of population decline of one of the world rarest raptors, the Spanish imperial eagle (Aquila adalberti). Consequently it has resulted in an increasing awareness of this problem amongst land managers and the public at large, as well as increased research into the distribution of electrocution events and likely mitigation measures. Methodology/Principal Findings We provide information of how mitigation measures implemented on a regional level under the conservation program of the Spanish imperial eagle have resulted in a positive shift of demographic trends in Spain. A 35 years temporal data set (1974–2009) on mortality of Spanish imperial eagle was recorded, including population censuses, and data on electrocution and non-electrocution of birds. Additional information was obtained from 32 radio-tracked young eagles and specific field surveys. Data were divided into two periods, before and after the approval of a regional regulation of power line design in 1990 which established mandatory rules aimed at minimizing or eliminating the negative impacts of power lines facilities on avian populations. Our results show how population size and the average annual percentage of population change have increased between the two periods, whereas the number of electrocuted birds has been reduced in spite of the continuous growing of the wiring network. Conclusions Our results demonstrate that solving bird electrocution is an affordable problem if political interest is shown and financial investment is made. The combination of an adequate spatial planning with a sustainable development of human infrastructures will contribute positively to the conservation of the Spanish imperial eagle and may underpin population growth and range expansion, with positive side effects on other endangered

  14. Radon assessment in thermal waters in Imbabura and Pichincha provinces

    International Nuclear Information System (INIS)

    Aragon, Mayra


    The radon is a radioactive, odorless and colorless gas, that generated in the terrestrial crust by the radioactive decay of the radio, originating of the chain of disintegration of the Uranium-238, can migrate considerable distances during its short time of life (3.82 days), from the ground to the water and later to the atmosphere. For the accomplishment of the preliminary study of quantification of radon in thermal sources, it was come to the sampling from radon-222 in bath waters different from the provinces of Pichincha and Imbabura. For which a particle accountant was used alpha, that uses the method of flashing, emitted by ionizing particles at the moment at which the radium decays in its descendant radon, and this one in its next descendants. The water samples are analyzed in the Pylon model RM-1003, particle accountant alpha, that uses for the harvesting of the gas, cameras that contain sensible detectors activated zinc sulfide cells with silver. For this sampling it was taken into account qualitative factors like: rain temperature, presence, origin of the source, proximity of some hill or volcano, presence of seismic movements, among others. These parameters could affect to the measurements of concentration of radon. Of the obtained results, we can conclude that of the 13 bath, those of the province of Pichincha, specially three of them (Tesalia, Sillunchi, Cunuyacu), contain greater concentration of radon that those of the province of Imbabura. In addition in general for all the selected bath it was verified that the concentration of radon is greater for the source than for the swimming pool. Finally it is possible to be emphasized values of concentration of radon that are around 1000-15000 Bq/m3 for the source, and the swimming pool of 100-800 Bq/m3. (The author)


    Directory of Open Access Journals (Sweden)

    Shashank Yeshwant Kothari


    Full Text Available BACKGROUND Removal of a part of a limb through one or more bones termed amputation is done for various causes. Properly performed amputation is a reconstructive procedure. Effective postoperative rehabilitation reduces disability and helps in proper shaping of the residual limb leading to final prosthetic fitment. The aim of the study is to compare effect of rigid dressing and Immediate Postoperative Prosthesis (IPOP using a simple and cheap pylon developed by the first author with soft dressing in respect of stump maturation and function in lower limb amputees. MATERIALS AND METHODS Fifty one patients with lower limb amputations were included in the study and randomised into two groups. Twenty four patients completed follow-up in the study group of rigid dressing with early postoperative prosthetic fitting while twenty patients completed with soft dressing. Stump maturation as measured by girth and volumetric assessment and complications of residual pain and phantom pain were compared at six weeks and twelve weeks with baseline data. Statistical Analysis- Done with SPSS for Windows version 17. Independent-T test was used for comparison of continuous variables and Chi-square and Fischer exact test was used for comparison of dichotomous responses. Settings and Design- The study was done in a multispecialty teaching hospital of a metro city. It was a well-structured comparative study done after addressing all safety and ethical issues. RESULTS Stump maturation was significantly better and the stump complications reduced in the study group. CONCLUSION Rigid dressing with IPOP has proven to be significantly superior to soft dressing in terms of maturation of stump and residual complications in lower limb amputations.

  16. Investigation of Appropriate Applications for Reuse of Conditionally Released Materials from Decommissioning

    International Nuclear Information System (INIS)

    Daniska, V.; Vasko, M.; Necas, V.


    During the decommissioning (D and D) phase of nuclear facility life cycle a lot of original facility materials are generated as a primary decommissioning waste. One portion of these materials is unconditionally releasable, i.e. their radioactivity content is below the stipulated concentration limits for clearance thus they can be further recycled or dumped without any constraints as a conventional waste. Second portion of generated waste is waste with radioactivity content higher than limits for free release and it has to be handled and disposed of as the radioactive waste (RAW) within special RAW repositories. Disposal of RAW is quite expensive therefore it seems to be reasonable to reduce amount of waste destined for disposal and to identify RAW with radioactivity content slightly higher than stipulated concentration limits for unconditional release which could be released with some constraints for further recycling and reuse while stipulated safety requirements are observed, i.e. conditional release of RAW. The most perspective materials from decommissioning for such material reuse are steel and concrete. These materials can be reused within the long term robust constructions for applications with infrequent or only short time presence of personnel/public, minimum interaction of human with materials and controllable interaction of materials with environment. Ideal applications for deployment of such materials are steel reinforcement in pylons for highways, tunnel linings, industry prefabricates, big tanks or linings in nuclear applications, for concrete debris it can be filling material for road construction. Presented paper deals with preconditions for reuse of conditionally released materials. It maps legal pre-requisites in the Slovak Republic, appropriate material application scenarios, methodology of assessment of impact on human health and environment - external and internal exposure assessment, possible optimisation of scenarios and estimation of

  17. Relating soil solution Zn concentration to diffusive gradients in thin films measurements in contaminated soils. (United States)

    Degryse, Fien; Smolders, Erik; Oliver, Ian; Zhang, Hao


    The technique of diffusive gradients in thin films (DGT) has been suggested to sample an available fraction of metals in soil. The objectives of this study were to compare DGT measurements with commonly measured fractions of Zn in soil, viz, the soil solution concentration and the total Zn concentration. The DGT technique was used to measure fluxes and interfacial concentrations of Zn in three series of field-contaminated soils collected in transects toward galvanized electricity pylons and in 15 soils amended with ZnCl2 at six rates. The ratio of DGT-measured concentration to pore water concentration of Zn, R, varied between 0.02 and 1.52 (mean 0.29). This ratio decreased with decreasing distribution coefficient, Kd, of Zn in the soil, which is in agreement with the predictions of the DGT-induced fluxes in soils (DIFS) model. The R values predicted with the DIFS model were generally larger than the observed values in the ZnCl2-amended soils at the higher Zn rates. A modification of the DIFS model indicated that saturation of the resin gel was approached in these soils, despite the short deployment times used (2 h). The saturation of the resin with Zn did not occur in the control soils (no Zn salt added) or the field-contaminated soils. Pore water concentration of Zn in these soils was predicted from the DGT-measured concentration and the total Zn content. Predicted values and observations were generally in good agreement. The pore water concentration was more than 5 times underpredicted for the most acid soil (pH = 3) and for six other soils, for which the underprediction was attributed to the presence of colloidal Zn in the soil solution.

  18. Thermal and physiochemical properties of pellets with power aims made of sawmill residual product

    International Nuclear Information System (INIS)

    Casanova Treto, Pedro; Solis, Kattia; Carrillo, Tonny


    Sawmill residual product of Pylon (Hyeronima alchorneoides) and Eucalyptus (Eucalyptus spp) species was used to produce pellets under different conditions of densification. Experimental equipment was used to determine the thermal conductivity, thermal diffusivity and specific heat. Physicochemical properties of the pellets obtained under different conditions of densification, such as ash content and calorific value were determined. The content of nitrogen, chlorine and sulfur present in the material used to produce the pellets was estimated. Thermal conductivity values were determined between 0,253 W/m·K and 0,279 W/m·K; 1,748 m2 /s and 2,314 m2 /s for the thermal diffusivity, and in the case of specific heat were determined values between 3,019 kJ/kg·K and 2,183 kJ/kg·K. The high heat values was between 18 907 kJ/kg and 18 960 kJ/kg. An ash content of 1,31% was determined on a dry basis. Finally, the content of nitrogen, chlorine and sulfur determined in the residual biomass used, corresponds to 0,1129%, 0,0592 % and 0,0317%, respectively. A direct relationship between increasing the bulk density of the pellets and the thermal properties was determined. The calorific value and the ash content had a negligible effect due to the treatments applied. The estimated content of N, Cl and S corresponds to that expected in the selected biomass. Comparison of the properties of the pellets produced under the conditions studied -densification, against regulations-, showed acceptable results, entering these in terms of different categories of quality. (author) [es

  19. Global-Local Analysis and Optimization of a Composite Civil Tilt-Rotor Wing (United States)

    Rais-Rohani, Masound


    This report gives highlights of an investigation on the design and optimization of a thin composite wing box structure for a civil tilt-rotor aircraft. Two different concepts are considered for the cantilever wing: (a) a thin monolithic skin design, and (b) a thick sandwich skin design. Each concept is examined with three different skin ply patterns based on various combinations of 0, +/-45, and 90 degree plies. The global-local technique is used in the analysis and optimization of the six design models. The global analysis is based on a finite element model of the wing-pylon configuration while the local analysis uses a uniformly supported plate representing a wing panel. Design allowables include those on vibration frequencies, panel buckling, and material strength. The design optimization problem is formulated as one of minimizing the structural weight subject to strength, stiffness, and d,vnamic constraints. Six different loading conditions based on three different flight modes are considered in the design optimization. The results of this investigation reveal that of all the loading conditions the one corresponding to the rolling pull-out in the airplane mode is the most stringent. Also the frequency constraints are found to drive the skin thickness limits, rendering the buckling constraints inactive. The optimum skin ply pattern for the monolithic skin concept is found to be (((0/+/-45/90/(0/90)(sub 2))(sub s))(sub s), while for the sandwich skin concept the optimal ply pattern is found to be ((0/+/-45/90)(sub 2s))(sub s).

  20. A high voltage power line: the route with the least environmental and health impact. Public consultation on the plan to rebuild the 400 kV power line between Lille and Arras

    International Nuclear Information System (INIS)

    Carlier, Jean-Louis; Chardonnet, Claude


    The upgrade to double-circuit of the 400-kV power line between Avelin and Gavrelle (Northern France) was first set in motion to improve security and to adapt the network to renewable energy sources or energy transition. Since 2011, it has been the object of an unprecedented consultation process, in terms of duration as well as magnitude. From 2012 to 2015, after much discussion, the contracting authority, Reseau Transport d'Electricite (RTE), determined the line with the least consequential environmental and health effects and presented it to the 2016 spring public inquiry. Information and communication requirements were adapted at each stage of the project, to take local concerns into account. Health concerns about the magnetic fields and noise generated by the electric lines were expressed from the very beginning of the consultation and were therefore treated with special care, through knowledge-sharing, debate and specific studies. A health committee, comprising volunteers from various backgrounds, was entrusted with informing the general public and providing suggestions to RTE and the health authorities, through in-depth discussions about health issues. The committee also asked RTE to conduct studies and measure electromagnetic fields to support an informed decision. As a result, the contracting authority defined the route of the electric line based primarily on the distance between houses and the line. The committee also obtained further commitments from RTE to minimize the magnetic fields emitted by the line with a new type of pylon and to monitor the effects on the people living along the line over time. During the course of this consultation process, shared knowledge together with a continuous dialogue on local health concerns aided the search for the route with the least consequential environmental and health impact. (authors)

  1. Diffusive Soil Degassing of Radon and Carbon Dioxide at Ilopango Caldera, El Salvador, Central America (United States)

    Ransom, L.; Lopez, D. L.; Hernandez, P.


    Ilopango Caldera lies 10 Km east of San Salvador, El Salvador and holds Ilopango Lake, the largest body of fresh water in El Salvador. There is currently no observed fumarolic activity within the caldera system. However, the last eruption occurred in 1880. In November - December, 1999, radon gas concentrations (pCi/l) were measured using a Pylon AB5 radon monitor, and flux of CO2 (g/m2/day) was determined using the accumulation chamber method at 106 sampling stations around the lake, along and across the caldera walls. Gas samples were also collected to determine the isotopic composition of C in CO2. CO2 fluxes did not show high values characteristic of other volcanic systems, values ranged from 0.7 to 9.2 g/m2/day with an average value of 3.9. These values are similar to the low values of the background population observed in nearby San Salvador volcano. Highest values are observed to the east and west of the lake. Isotopic values for C in soil gases do not show an important magmatic component. Radon concentrations present three distinct populations with the highest values occurring to the southwest. Thoron concentrations are higher close to the caldera walls than inside the caldera due to the possible higher rock fracturing in that region. Measurements taken in March 2001, after the January 13 and February 13, 2001 earthquakes did not show significant variations in CO2 fluxes. However, radon concentrations varied due to the high seismicity that lasted several months after these earthquakes. These results suggest that the magmatic system of Ilopango Caldera is not emitting high fluxes of CO2 to the atmosphere throughout the caldera soils. Subaquatic emissions of CO2 have not been evaluated. However, subaquatic hydrothermal discharges have not been identified at this calderic lake.

  2. Mechanical characterization and validation of poly (methyl methacrylate)/multi walled carbon nanotube composite for the polycentric knee joint. (United States)

    Arun, S; Kanagaraj, S


    Trans femoral amputation is one of the most uncomfortable surgeries in patient׳s life, where the prosthesis consisting of a socket, knee joint, pylon and foot is used to do the walking activities. The artificial prosthetic knee joint imitates the functions of human knee to achieve the flexion-extension for the above knee amputee. The objective of present work is to develop a light weight composite material for the knee joint to reduce the metabolic cost of an amputee. Hence, an attempt was made to study the mechanical properties of multi walled carbon nanotubes (MWCNT) reinforced Poly (methyl methacrylate) (PMMA) prepared through melt mixing technique and optimize the concentration of reinforcement. The PMMA nanocomposites were prepared by reinforcing 0, 0.1, 0.2, 0.25, 0.3 and 0.4 wt% of MWCNT using injection moulding machine via twin screw extruder. It is observed that the tensile and flexural strength of PMMA, which were studied as per ASTM D638 and D790, respectively, were increased by 32.9% and 26.3% till 0.25 wt% reinforcement of MWCNT. The experimental results of strength and modulus were compared with theoretical prediction, where a good correlation was noted. It is concluded that the mechanical properties of PMMA were found to be increased to maximum at 0.25 wt% reinforcement of MWCNT, where the Pukanszky model and modified Halpin-Tsai model are suggested to predict the strength and modulus, respectively, of the PMMA/MWCNT composite, which can be opted as a suitable materiel for the development of polycentric knee joint. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Experimental Investigation of a Helicopter Rotor Hub Flow (United States)

    Reich, David

    The rotor hub system is by far the largest contributor to helicopter parasite drag and a barrier to increasing helicopter forward-flight speed and range. Additionally, the hub sheds undesirable vibration- and instability-inducing unsteady flow over the empennage. The challenges associated with rotor hub flows are discussed, including bluff body drag, interactional aerodynamics, and the effect of the turbulent hub wake on the helicopter empennage. This study was conducted in three phases to quantify model-scale rotor hub flows in water tunnels at The Pennsylvania State University Applied research lab. The first phase investigated scaling and component interaction effects on a 1:17 scale rotor hub model in the 12-inch diameter water tunnel. Effects of Reynolds number, advance ratio, and hub geometry configuration on the drag and wake shed from the rotor hub were quantified using load cell measurements and particle-image velocimetry (PIV). The second phase focused on flow visualization and measurement on a rotor hub and rotor hub/pylon geometry in the 12-inch diameter water tunnel. Stereo PIV was conducted in a cross plane downstream of the hub and flow visualization was conducted using oil paint and fluorescent dye. The third phase concentrated on high accuracy load measurement and prediction up to full-scale Reynolds number on a 1:4.25 scale model in the 48-inch diameter water tunnel. Measurements include 6 degree of freedom loads on the hub and two-component laser-Doppler velocimetry in the wake. Finally, results and conclusions are discussed, followed by recommendations for future investigations.

  4. The social impact of the snowfall of 8 March 2010 in Catalonia (United States)

    Amaro, J.; Llasat, M. C.; Aran, M.


    The snowfall of 8 March 2010 affected almost all Catalonia, but especially the northeast where snow thickness was between 20 and 30 cm, locally with higher values up to 60 cm. Strong winds followed the event, exceeding 90 km/h in some places. As a result, infrastructures and public services, also private properties were damaged. Thousands of people were left stranded by the circulatory collapse, suspensions of railway service and by falling branches or trees on road infrastructures blocking accesses to residential areas. The regional government approved funds of 21.4 millions of Euros to mitigate the damage caused by this event, mainly invested in forest cleanup operations and in repairing road damage. The social impact of this event has been so high that 210 news have been published in a newspaper until 23 April, 190 of them during the month of March. From the study of the characteristics of this episode it can be stated that in the coast and pre-costal area, temperature at the same moment of precipitation was between 0ºC and 2ºC and humidity was high. In these zones, the type of precipitation was wet snow. It has to be considered that the combination of wet snow and wind can be a risk because of the ice-weight accumulated on objects (trees, electricity pylons...). As a consequence important damage happened in power network with significant collateral effects and more than 450,000 customers were affected by a power outage during some days. In this study we will compare the consequences of this event with others by means of information published in press. As a result, some set of consequences that are repeated regardless of the magnitude of the phenomenon will be identified. Finally, this event is also an example of the incision of social networks. This snowfall has been classified by mass media as the first "snowfall 2.0": 81600 entrances in Google, 132 Facebook groups and 750 videos made by amateurs in internet. From this study, we will present some reflexions

  5. Advanced Computational and Experimental Techniques for Nacelle Liner Performance Evaluation (United States)

    Gerhold, Carl H.; Jones, Michael G.; Brown, Martha C.; Nark, Douglas


    The Curved Duct Test Rig (CDTR) has been developed to investigate sound propagation through a duct of size comparable to the aft bypass duct of typical aircraft engines. The axial dimension of the bypass duct is often curved and this geometric characteristic is captured in the CDTR. The semiannular bypass duct is simulated by a rectangular test section in which the height corresponds to the circumferential dimension and the width corresponds to the radial dimension. The liner samples are perforate over honeycomb core and are installed on the side walls of the test section. The top and bottom surfaces of the test section are acoustically rigid to simulate a hard wall bifurcation or pylon. A unique feature of the CDTR is the control system that generates sound incident on the liner test section in specific modes. Uniform air flow, at ambient temperature and flow speed Mach 0.275, is introduced through the duct. Experiments to investigate configuration effects such as curvature along the flow path on the acoustic performance of a sample liner are performed in the CDTR and reported in this paper. Combinations of treated and acoustically rigid side walls are investigated. The scattering of modes of the incident wave, both by the curvature and by the asymmetry of wall treatment, is demonstrated in the experimental results. The effect that mode scattering has on total acoustic effectiveness of the liner treatment is also shown. Comparisons of measured liner attenuation with numerical results predicted by an analytic model based on the parabolic approximation to the convected Helmholtz equation are reported. The spectra of attenuation produced by the analytic model are similar to experimental results for both walls treated, straight and curved flow path, with plane wave and higher order modes incident. The numerical model is used to define the optimized resistance and reactance of a liner that significantly improves liner attenuation in the frequency range 1900-2400 Hz. A

  6. Fielding An Amphibious UAV: Development, Results, and Lessons Learned (United States)

    Pisanich, Greg; Morris, Stephen


    This report summarizes the work completed on the design and flight-testing of a small, unmanned, amphibious demonstrator aircraft that flies autonomously. The aircraft named ACAT (Autonomous Cargo Amphibious Transport) is intended to be a large cargo carrying unmanned aircraft that operates from water to avoid airspace and airfield conflict issues between manned and unmanned aircraft. To demonstrate the feasibility of this concept, a demonstrator ACAT was designed, built, and flown that has a six-foot wingspan and can fly autonomously from land or water airfield. The demonstrator was designed for a 1-hour duration and 1-mile telemetry range. A sizing code was used to design the smallest demonstrator UAV to achieve these goals. The final design was a six-foot wingspan, twin hull configuration that distributes the cargo weight across the span, reducing the wing structural weight. The demonstrator airframe was constructed from balsa wood, fiberglass, and plywood. A 4-stroke model airplane engine powered by methanol fuel was mounted in a pylon above the wing and powers the ACAT UAV. Initial flight tests from land and water were conducted under manual radio control and confirmed the amphibious capability of the design. Flight avionics that were developed by MLB for production UAVs were installed in the ACAT demonstrator. The flight software was also enhanced to permit autonomous takeoff and landing from water. A complete autonomous flight from ahard runway was successfully completed on July 5, 2001 and consisted of a take-off, rectangular flight pattern, and landing under complete computer control. A completely autonomous flight that featured a water takeoff and landing was completed on October 4, 2001. This report describes these activities in detail and highlights the challenges encountered and solved during the development of the ACAT demonstrator. hard runway was successfully completed on July 5, 2001 and consisted of a take-off, rectangular flight pattern, and

  7. The application of soil-gas geochemistry to precisely locate La Victoria fault near Paracotos (Venezuela)

    International Nuclear Information System (INIS)

    LaBrecque, J.J.; Rosales, P.A.; Cordoves, P.R.


    Full text: Measurements of radon (total radon, Radon-222 and Radon-220) and other soil-gases (CO 2 , O 2 and H 2 ) were performed routinely during 1998 and 1999 across a narrow valley near Paracotos, Venezuela in an attempt to precisely locate the La Victoria fault. The transect was about 300 meters long with eleven sampling points. The soil-gas probes were inserted to a depth of 45 cm in the beginning and later on completely to a depth of 63 cm. The radon sampling and measurements were accomplished with a Pylon AB-5 radiation monitor and Lucas scintillation cells. The other soil-gases were directly determined with an Anagas, CD95 monitor and an Infra-red Gas Analyzer (MKIIC) both coupled with a Hydrogen pod. The radon values for more than twenty different sampling periods over a two year period resulted with anomalous values between 75 and 150 meters along the transect. There were three consecutive anomalous values each time. But strangely, the anomalies of the radon values were in the form of a doublet at 116 and 141 meters rather than a simple single peak in the middle and the gas flow was similar for the sampling points between 75 and 150 meters. The graph of the relative CO 2 values were usually similar to the radon graphs but in some cases, the anomalous values were seen as a simple single peak and corresponded to the 141 meter sampling point. While the anomalous values of Hydrogen were usually in a form of a single peak that corresponded with 141 meter sampling point. Only a few times were values for Hydrogen higher than 100 ppm and detected at most of the sampling points, usually only one or two points resulted with small values near the 141 meter sampling point. Based on the radon values alone, we would have to conclude that the fault probably lies near or between the 116 and 141 meter sampling points, but with the additional data of the CO 2 and H 2 soil-gases one could say that the fault is probably near the 141 meter sampling point. Thus, we have

  8. ARM Aerial Facility ArcticShark Unmanned Aerial System (United States)

    Schmid, B.; Hubbell, M.; Mei, F.; Carroll, P.; Mendoza, A.; Ireland, C.; Lewko, K.


    The TigerShark Block 3 XP-AR "ArcticShark" Unmanned Aerial System (UAS), developed and manufactured by Navmar Applied Sciences Corporation (NASC), is a single-prop, 60 hp rotary-engine platform with a wingspan of 6.5 m and Maximum Gross Takeoff Weight of 295 Kg. The ArcticShark is owned by the U.S. Department of Energy (DOE) and has been operated by Pacific Northwest National Laboratory (PNNL) since March 2017. The UAS will serve as an airborne atmospheric research observatory for DOE ARM, and, once fully operational, can be requested through ARM's annual call for proposals. The Arctic Shark is anticipated to measure a wide range of radiative, aerosol, and cloud properties using a variable instrument payload weighing up to 46 Kg. SATCOM-equipped, it is capable of taking measurements up to altitudes of 5.5 Km over ranges of up to 500 Km. The ArcticShark operates at airspeeds of 30 to 40 m/s, making it capable of slow sampling. With a full fuel load, its endurance exceeds 8 hours. The aircraft and its Mobile Operations Center (MOC) have been hardened specifically for operations in colder temperatures.ArcticShark's design facilitates rapid integration of various types of payloads. 2500 W of its 4000 W electrical systems is dedicated to payload servicing. It has an interior payload volume of almost 85 L and four wing-mounted pylons capable of carrying external probes. Its payload bay volume, electrical power, payload capacity, and flight characteristics enable the ArcticShark to accommodate multiple combinations of payloads in numerous configurations. Many instruments will be provided by the ARM Aerial Facility (AAF), but other organizations may eventually propose instrumentation for specific campaigns. AAF-provided measurement capabilities will include the following atmospheric state and thermodynamics: temperature, pressure, winds; gases: H2O and CO2; up- and down-welling broadband infrared and visible radiation; surface temperature; aerosol number concentration

  9. Aeroelastic response and stability of tiltrotors with elastically-coupled composite rotor blades. Ph.D. Thesis (United States)

    Nixon, Mark W.


    There is a potential for improving the performance and aeroelastic stability of tiltrotors through the use of elastically-coupled composite rotor blades. To study the characteristics of tiltrotors with these types of rotor blades it is necessary to formulate a new analysis which has the capabilities of modeling both a tiltrotor configuration and an anisotropic rotor blade. Background for these formulations is established in two preliminary investigations. In the first, the influence of several system design parameters on tiltrotor aeroelastic stability is examined for the high-speed axial flight mode using a newly-developed rigid-blade analysis with an elastic wing finite element model. The second preliminary investigation addresses the accuracy of using a one-dimensional beam analysis to predict frequencies of elastically-coupled highly-twisted rotor blades. Important aspects of the new aeroelastic formulations are the inclusion of a large steady pylon angle which controls tilt of the rotor system with respect to the airflow, the inclusion of elastic pitch-lag coupling terms related to rotor precone, the inclusion of hub-related degrees of freedom which enable modeling of a gimballed rotor system and engine drive-train dynamics, and additional elastic coupling terms which enable modeling of the anisotropic features for both the rotor blades and the tiltrotor wing. Accuracy of the new tiltrotor analysis is demonstrated by a comparison of the results produced for a baseline case with analytical and experimental results reported in the open literature. Two investigations of elastically tailored blades on a baseline tiltrotor are then conducted. One investigation shows that elastic bending-twist coupling of the rotor blade is a very effective means for increasing the flutter velocity of a tiltrotor, and the magnitude of coupling required does not have an adverse effect on performance or blade loads. The second investigation shows that passive blade twist control via

  10. Optimization of composite tiltrotor wings with extensions and winglets (United States)

    Kambampati, Sandilya

    Tiltrotors suffer from an aeroelastic instability during forward flight called whirl flutter. Whirl flutter is caused by the whirling motion of the rotor, characterized by highly coupled wing-rotor-pylon modes of vibration. Whirl flutter is a major obstacle for tiltrotors in achieving high-speed flight. The conventional approach to assure adequate whirl flutter stability margins for tiltrotors is to design the wings with high torsional stiffness, typically using 23% thickness-to-chord ratio wings. However, the large aerodynamic drag associated with these high thickness-to-chord ratio wings decreases aerodynamic efficiency and increases fuel consumption. Wingtip devices such as wing extensions and winglets have the potential to increase the whirl flutter characteristics and the aerodynamic efficiency of a tiltrotor. However, wing-tip devices can add more weight to the aircraft. In this study, multi-objective parametric and optimization methodologies for tiltrotor aircraft with wing extensions and winglets are investigated. The objectives are to maximize aircraft aerodynamic efficiency while minimizing weight penalty due to extensions and winglets, subject to whirl flutter constraints. An aeroelastic model that predicts the whirl flutter speed and a wing structural model that computes strength and weight of a composite wing are developed. An existing aerodynamic model (that predicts the aerodynamic efficiency) is merged with the developed structural and aeroelastic models for the purpose of conducting parametric and optimization studies. The variables of interest are the wing thickness and structural properties, and extension and winglet planform variables. The Bell XV-15 tiltrotor aircraft the chosen as the parent aircraft for this study. Parametric studies reveal that a wing extension of span 25% of the inboard wing increases the whirl flutter speed by 10% and also increases the aircraft aerodynamic efficiency by 8%. Structurally tapering the wing of a tiltrotor

  11. Ringing of White Storks Ciconia ciconia in NE Slovenia during the 1984–2013 period

    Directory of Open Access Journals (Sweden)

    Bračko Franc


    Full Text Available In a period of 30 years (1984-2013, 1,535 White Stork pulli were ringed on nest and 1,226 nests examined in NE Slovenia. The ringing was implemented in the regions of Dravsko polje, Slovenske gorice and Pomurje. In each season, from 9 to 85 nests were examined, the great majority of them built on overhead powerline pylons. On average, 51.16 pulli or 16.66% were ringed and 40.86 or 18.91% nests visited compared to the census of fledged pulli and inventoried nests in 1999 in NE Slovenia. A total of 71 finds or 4.6% were registered and 37 rings or 52% finds read. There were 26 (36.62% local recoveries, while in foreign countries 34 (47.88% recoveries of Slovenian-ringed storks were made. Two of our recoveries were registered abroad prior to 1984. There were 11 (15.49% foreign recoveries. Local recoveries (n = 26 indicate breeding relationship (mixing between the eastern and southern Slovenian breeding populations. The longest distance of breeding was 115 km in a beeline, the shortest 62 km (n = 4. Other 12 local recoveries at 1 to 38 km from the place of hatching concerns the native NE breeding area. Young sexually mature storks search for new breeding sites only in their fourth year of age. No ringed stork returned to the native nest as a young breeder. The oldest was 14 years old. Some of them breed in the wider area of the Pannonian Plain outside Slovenia, e.g. 3 in Austria, 2 in Serbia and 1 in Croatia. One of them bred in Slovakia 463 km away. In view of the presented recoveries it has been ascertained that the storks from NE Slovenia migrate across the Pannonian Plain, the Balkans and Asia Minor, down to the South African Republic of 8,923 km in a beeline (4 recoveries, using the eastern migration route. The western migration route was not ascertained. The majority of recoveries originated from the autumn migration period, with only one recovery known from the spring migration period. No less than 23 ringed storks, particularly young ones

  12. Influence of dynamic excitation on the bearing capacity of reinforced concrete columns exposedto fire effects Влияние динамического эффекта на несущую способность железобетонных колонн, работающих в условиях огневых воздействий

    Directory of Open Access Journals (Sweden)

    Avetisyan Levon Avetisovich


    Full Text Available This article provides an example of the calculation of eccentrically compressed reinforced concrete elements exposed to dynamic loads and fire effects. The dynamic factor for the concrete under regular conditions is available, and it exceeds one in any case. However, in case of a fire exposure, the value of this factor varies from 0,4 to 0,8, depending on the loading rate and temperature. The value of the dynamic factor was identified in the course of an experiment; thereafter, the pattern of influence of the dynamic effect caused by the progressive collapse of buildings and produced onto the bearing capacity and fire resistance of compressed elements of the pylon and the column was identified. ANSYS 12.1 software package was employed to perform the fire resistance analysis of the pylon on the 1st floor of a 59-storey building. The problem was modeled in the 3D formulation. It represented a pylon exposed to static loading and standard fire conditions. For comparison purposes, bearing capacity values were calculated for different values of the thermal load.The calculation of temperature fields was based on the resolution of boundary value problems of transient heat conduction in capillary-porous bodies.The solution to the problem of the four-sided fire exposure at standard fire temperature values was obtained in characteristic points of the support structure to assess the change in its load-bearing capacity.It is proven that dynamic effects of a fire reduce the bearing capacity of columns by 40 %. Therefore, the analysis of the bearing capacity of structures in terms of their fire resistance should take account of the possibility of progressive collapse of buildings.Приведен пример расчета внецентренно сжатых железобетонных элементов, работающих в условиях динамических нагрузок и огневых воздействий. Коэффициенты д

  13. Radiocarbon dating of the first Turkish bridge over the River Tisza

    International Nuclear Information System (INIS)

    Szanto, Zs.; Molnar, M.; Futo, I.; Svingor, E.; Rinyu, L.; Palcsu, L.; Morgos, A.


    Complete text of publication follows. Situated at the junction of the Tisza and Zagyva rivers, the territory of the presentday Szolnok town has been nearly continuously inhabited since the beginning of the Neolithic age. Gravures and other written documents attested the presence of bridge(s) over the River Tisza during the centuries. The first bridges were mentioned in 1526 as temporary pontoon bridges used for the needs of the Turkish army. The remainings of an old bridge on the River Tisza were discovered last summer in excavations of the river bank at Szolnok. It was supposed that the remainings found were probably part of the bridge built in 1562, the first wooden bridge over the River Tisza mentioned in the letter of bishop of town Eger [1] but could also been parts of a bridge built much later. Although the mineral water and sodium silicate have penetrated the wood logs resulting in though blackish-brown and hardened by petrifaction samples, the original character of the pylons was still evident. Six timbers (7 samples) have been radiocarbon dated. Samples were physically and chemically pre-treated to remove contamination before they were converted to CO 2 . In order to avoid the 'old wood' effect, in which the inner tree rings may be tenths of years older than the outer ring of sapwood deposited just before the tree died the exterior was removed. Physical treatments consisted of cleaning, sorting, grinding and sieving. Chemical treatment included the standard A/A/A method. The pre-treated samples were combusted to CO 2 in a controlled oxygen stream. The purified CO 2 was trapped and measured by gas proportional counting [2]. Correction for fractionation was done by measuring the δ 13 C PDB value. Calibration of 14 C dates to calendar years was performed using the Calib 4.4.2 program [3]. The results showed the wood sample prepared by A/A/A contained contaminants of more recent carbon material which gave it a more recent date and spread the results over four

  14. Vulnerabilidad sísmica y capacidad de carga de un puente atirantado basados en confiabilidad estructural Seismic vulnerability and loading capacity of a wire strained bridge based on structural reliability

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    Edgar Muñoz


    tests, trials tests on material mechanical properties, environmental vibrations, measurements on the effects of traffic load, wireless instrumentation, loading tests, wire strainers tensile strength, etc. Additionally, the study explains structural models on finite elements, which were developed for the bridge, as well as its calibration process based on the loading test, and dynamical properties determined on experimental basis. Furthermore, the study indicates the way stress records collection of all structural elements was conducted, during the construction process, in accordance with the job site log-book. As for reliability, a seismic threat analysis was made as well as dynamic responses on the bridge site, where nine spectrums were obtained at different return periods. By studying strength probability curves and seismic loads of pylons, it was found they have reliability indexes in accordance with recommendations by the international regulations. However, one of the superstructure's elements, which were introduced to evaluate its capacity on traffic effects, has a reliability index far higher than the ranges recommended by international regulations. Finally, some wire strainers have higher level tensions than specifications admitted during its design and international recommendations for these kinds of bridges.

  15. [Long-term results of calcaneal fracture treatment by open reduction and internal fixation using a calcaneal locking compression plate from an extended lateral approach]. (United States)

    Zeman, P; Zeman, J; Matejka, J; Koudela, K


    to enable the patient to begin rehabilitation with early mobilization. A passive rehabilitation usually started on the first post-operative day, and full weight-bearing of the extremity was allowed not earlier than 3 months post-operatively. Regular check-ups were at 6 weeks, 3, 6 and 12 months and then every year. The mid-term results were evaluated by the system of Rowe et al., scoring rest pain, possibility of return to preinjury jobs, use of walking aids, restriction of physical activity and limping. RESULTS The most frequent cause of injury was a fall or jump from height; this was recorded in 27 patients (93.1 %). An open fracture was diagnosed on two occasions (6.9 %). Bilateral calcaneal fractures were found in six patients (20.7 %); four (13.8 %) were treated by bilateral ORIF-calcaneal LPC and two (6.9 %) underwent closed reduction on one and Kirschnerwire transfixation on the other extremity. A combined injury to the musculoskeletal system was diagnosed in 11 patients (38 %), in whom four (13.8 %) had a tibial pylon fracture of the contralateral limb and four (13.8 %) had a thoracolumbar spine fracture. The surgical procedure was performed on average within 11.7 days of injury, and the average hospital stay was 18.2 days (range, 6 to 18 days). Early post-operative complications were recorded in six patients (20.7 %). Wound dehiscence was found in two (6.9 %), necrosis of wound edges in two (6.9 %), and early superficial infection responding to antibiotic therapy also in two patients (6.9 %). Deep infection, non-union or post-operative compartment syndrome were not recorded. Excellent Rowe scores were achieved in 10 patients (34.5 %), good in 15 (51.7 %) and satisfactory in two (6.9 %). Only two patients (6.9 %) reported poor outcome. The methods of classification and treatment of calcaneal fractures continue to be a frequently discussed topic. The technique of ORIF-calcaneal LCP from an extended lateral approach has recently been preferred for patients with

  16. El puente de Saint-Nazaire - Saint-Brévin – Francia

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    Editorial, Equipo


    Full Text Available As a consequence of the industrial and tourist development of the region, it was necessary to construct a bridge across the Loire taking into account conditions such as the geological nature of the Loire river bed, the passing of up to 200,000 t oil tankers and other factors which were of utmost importance for the design and the subsequent construction. The work consist of two access viaducts and the central metal bridge. The viaduct, the outlines of which are curved in mutually opposite senses, are of prestressed concrete. They are made up equal spans, each of which has a length of 50.70 m between the pile axes, with in all 22 on the north side and 30 on the south side. Each span consists of: 4 prefabricated girders which are joined at the ends by tie members; between the girders there is a 0.50 cm thick fill layer, over which there is a reinforced concrete slab. The supporting piers, also of reinforced concrete, have a foundation of piles which generally speaking rest on the rocky substratum of the riverbed. The metal part rests upon two main piers, situated on either side, with same type of foundation as mentioned above. On these are located inverted V-shape pylons, with a short vertical element, to which the cables that support the centre bridge deck are anchored, formed by 96 m and 16 m long spans, welded together after having been lifted to their final level. This project —the greatest in France and the one that has the greatest clear span among the works of this kind— has required three years of work utilizing the most modern techniques and systems. More than 80,000 m2 of concrete and more than 17,000 t of different kinds of steel have been used.Como consecuencia del desarrollo industrial y turístico de la región, fue preciso construir un puente sobre el Loira, contando con condicionantes tales como la naturaleza geológica del lecho del Loira, el paso de petroleros de hasta 200.000 t, y otros factores que influyeron grandemente

  17. Locomotor Dysfunction after Long-duration Space Flight and Development of Countermeasures to Facilitate Faster Recovery (United States)

    Mulavara, Ajitkumar; Wood, Scott; Cohen, Helen; Bloomberg, Jacob


    movement control and a functional mobility test to investigate overall functional locomotor ability. Postflight sessions were given on days 1, 2, 4, 7 after their return. Subjects walked on a treadmill driven at 1.8 m/s while performing a visual task. Motion data from head and trunk segmental motion data were obtained to calculate the angular head pitch (HP) movements during walking trials while subjects performed the visual task, to estimate the contributions of vestibular reflexive mechanisms in HP movements. Astronauts showed a heterogeneous response pattern of both increases and decreases in the amplitude of HP movement. We investigated the underlying mechanisms of this heterogeneity in postflight responses in head movement control by examining data obtained using the same experimental test paradigm on a vestibular clinical population (VC) and in normal subjects undergoing adaptation to acute body load support unloading. Results showed that exposure to unloaded locomotion caused a significant increase in HP movements, whereas in the VC patients the HP movements were significantly decreased. We infer that BLS-mediated somatosensory input centrally modulates vestibular input and can adaptively modify head-movement control during locomotion. Thus, space flight may cause a central adaptation of the converging vestibular and body load-sensing somatosensory systems. To investigate changes in functional mobility astronaut subjects walked at their preferred pace around an obstacle course consisting of several pylons and obstacles set up on a foam floor, which provided an unstable walking surface. Subjects were instructed to walk around the course as fast as possible without touching any of the objects on the course for a total of six individual trials per test session. One of the dependent measures was time to complete the course (TCC, sec). The learning rate over the six trials performed on preflight and the first day after landing (micro curve) was used to characterize the

  18. Assessment of Postflight Locomotor Performance Utilizing a Test of Functional Mobility: Strategic and Adaptive Responses (United States)

    Warren, L. E.; Mulavara, A. P.; Peters, B. T.; Cohen, H. S.; Richards, J. T.; Miller, C. A.; Brady, R.; Ruttley, T. M.; Bloomberg, J. J.


    have further analyzed the FMT data to characterize strategic and adaptive components during the postflight readaptation period. Crewmembers walked at a preferred pace through an obstacle course set up on a base of 10 cm thick medium density foam (Sunmate Foam, Dynamic Systems, Inc., Leicester, NC). The 6.0m X 4.0m course consisted of several pylons made of foam; a Styrofoam barrier 46.0cm high that crewmembers stepped over; and a portal constructed of two Styrofoam blocks, each 31cm high, with a horizontal bar covered by foam and suspended from the ceiling which was adjusted to the height of the crewmember s shoulder. The portal required crewmembers to bend at the waist and step over a barrier simultaneously. All obstacles were lightweight, soft and easily knocked over. Crewmembers were instructed to walk through the course as quickly and as safely as possible without touching any of the objects on the course. This task was performed three times in the clockwise direction and three times in the counterclockwise direction that was randomly chosen. The dependent measures for each trial were: time to complete the course (seconds) and the number of obstacles touched or knocked down. For each crewmember, the time to complete each FMT trial from postflight days 1, 2, 4, 7 and 25 were further analyzed. A single logarithmic curve using a least squares calculation was fit through these data to produce a single comprehensive curve (macro). This macro curve composed of data spanning 25 days, illustrates the re-adaptive learning function over the longer time scale term. Additionally, logarithmic curves were fit to the 6 data trials within each individual post flight test day to produce 5 separate daily curves. These micro curves, produced from data obtained over the course of minutes, illustrates the strategic learning function exhibited over a relative shorter time scale. The macro curve for all subjects exhibited adaptive motor learning patterns over the 25 day period. Howev, 9

  19. EDITORIAL: Message from the Editor Message from the Editor (United States)

    Thomas, Paul


    At the time of writing, the construction of ITER is making, quite literally, visible progress; buildings have gone up, the tokamak pit has been equipped with the seismic pads and pylons have been put in place for the high tension input to the power supplies. Most of the main procurement arrangements have been let and we will see an increasing volume of deliveries to the ITER site over the coming years. In addition, the National Ignition Facility has started full operation and will undoubtedly see important results coming from it in 2012. These projects are important reminders of what a monumental endeavour we are all engaged in and the potential of nuclear fusion to improve the long-term condition of the human race. We can be proud, therefore, that the Nuclear Fusion journal makes such an important contribution to controlled fusion programmes and is maintaining its position as the leading journal in the field. More than 350 articles are submitted each year from over 40 countries. Nuclear Fusion continues to be the most highly cited journal in the field, with an impact factor of 3.303, as listed in the ISI 2010 Science Citation Index. The journal depends on its authors and referees for its success and so I would like to thank them all for their hard work in 2011, which should maintain the level of readership and the citation indices for years to come. I sincerely hope that 2012 will be as good. Refereeing The Nuclear Fusion editorial office understands how much effort is required of our referees. The Editorial Board decided that an expression of thanks to our most loyal referees is appropriate and so, since January 2005, we have been offering the top ten most active referees over the past year a personal subscription to Nuclear Fusion with electronic access for one year, free of charge. This year, three of the top referees have reviewed five manuscripts in the period November 2010 to November 2011 and provided excellent advice to the authors. We have excluded our

  20. Pre- and post-construction studies of conflicts between birds and wind turbines in coastal Norway (BirdWind)

    Energy Technology Data Exchange (ETDEWEB)

    Bevanger, K.; Berntsen, F.; Clausen, S.; Dahl, E.L.; Flagstad, Oe.; Follestad, A.; Halley, D.; Hanssen, F.; Hoel, P.L.; Johnsen, L.; Kvaloey, P.; May, R.; Nygaard, T.; Pedersen, H.C.; Reitan, O.; Steinheim, Y.; Vang, R.


    connection to the planned extension of the existing power plant on Hitra I; the Hitra II Wind-Power Plant. Since 2003, 50 nestlings of white-tailed eagle have been equipped with satellite transmitters. In 2009, eight WTE nestlings were tagged, six with solar-powered and two with battery-powered transmitters. One was tagged within the wind-power plant, the others in close vicinity of it. The solar-powered transmitters used in 2009 were programmed to give one position per hour during summer in order to have finer resolution of movements for risk-modeling purposes. During winter less frequent downloading is scheduled, due to low light and poor battery-charging. One of the tagged nestlings was found killed by a turbine October 7. We have continued to collect feathers from active nests and chicks also in 2009, as well as from eagles killed in collisions with wind turbines. DNA-analyses from bones of six eagles killed by electrocution on power-line pylons on Smoela will also be included. For increased efficiency in the laboratory, and to streamline the production of DNA-data, the use of an extraction robot has been implemented. All WTE nest sites on Smoela were surveyed during the summer. Territorial activity, identified by either moulted adult feathers, chicks in the nest or fresh nest material, was confirmed in 61 different territories on the main island and in the surrounding archipelago. In these territories 27 chicks from 21 different clutches were recorded. This is the second highest number of chicks recorded ever on Smoela, giving a re-productive output of 0.44 chicks/confirmed occupied territory. In order to investigate behavioural differences for the WTE related to the distance from the turbines, data on flight activity (moving flight, social behaviour and soaring) and flight height (below, in and above the rotor zone) were collected at 12 vantage points, 6 from inside the wind-power plant area and 6 from control areas close to the power-plant area. The results indicate

  1. Optimal design and routing of power lines; ecological, technical and economic perspectives (OPTIPOL). Progress report 2009

    Energy Technology Data Exchange (ETDEWEB)

    Bevanger, K.; Bartzke, G.; Broeseth, H.; Gjershaug, J.O.; Hanssen, F.; Jacobsen, K.-O.; Kvaloey, P.; May, R.; Nygaard, T.; Pedersen, H.C.; Reitan, O.; Refsnaes, S.; Stokke, S.; Vang, R.


    mitigating measures. The study includes use of GPS-satellite telemetry to see how the eagle owls use the pylons during hunt-ing activities. This will also give data on eagle-owl movements and electrocution rate. In 2009 3 adult and 4 juvenile eagle owls were equipped with GPS-radio transmitters. (Author)

  2. Archaeological excavations at Gamzigrad - Romuliana in 2007-2008

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    Petković Sofija


    (canal A discovered inside the south room of Galerius' bath in 2004, which was constructed after the earlier structure and before the Imperial bath (Fig. 9. It is interesting that the part of the earlier building to the west of the thermae was not demolished during the construction of the Imperial residence. It was adapted and incorporated into the plan of the fortified palace. The original construction was a large public building, probably theprincipia, with a row of rooms around a large courtyard, the atrium. The entrance, which had a porch and a pylon with two square towers and thresholds made of stone slabs, was in the north. (Figs. 10-14 Previously, this building was mistakenly dated to the 4th-5th centuries, because it had been reused in Late Roman and Early Byzantine periods. (Figs. 15-18 However, based on the results of the new research, it could be dated to the 3rd century. .

  3. The Church of St. Stephan on Šćepan polje near Soko-grad

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    Popović Marko


    , along the southern wall of the western bay was the grave of the donor of the church of St. Stephan, Grand Duke Sandalj Hranić. This was the traditional position where the donor was buried, according to the custom or rather, the rule that had been practiced for centuries in the countries of the Byzantine Orthodox Christian world, and particularly in the Serbian lands. The duke's grave, marked by a stele in the form of a massive low coffin on a pedestal, was prepared while the church was being built given that it would have been impossible to install this large monolith that weighed approximately 2.5 tons in the church, later. Generally speaking, the donor's grave in the church of St. Stephan, is eloquent testimony of the donor's aspirations and beliefs. Besides the undoubtedly local feature of a funerary monument in the form of a stele, all its other characteristics emulate earlier models from the region of the Serbian lands. In front of the original church, at a later stage, which apparently followed soon after, a spacious narthex with a rectangular base was added on. Pylons of the belfry substructure were fitted into its eastern wall, which seems to have made that wall much thicker than the other walls of the narthex. This later erected narthex was not vaulted, which we concluded after analysing the preserved walls and the finds in the debris. Apparently, it had a flat ceiling construction, supported by massive beams that rested on consoles along the length of the northern and southern walls. The side entrances when the narthex was built were of the same dimensions as its western portal. However later, before installing the stone doorposts, both these entrances were narrowed down on their western, lateral sides, while the southern portal, in a later phase, was completely walled up. In the course of exploration, no reliable data was discovered regarding the position of the windows in the narthex. One can only assume that monophoric windows existed on the lateral walls