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This study, centered around the engineering context of the Wuxue Yangtze River Bridge, addresses the challenge of significant temperature-induced secondary internal forces in the short lower tower column. A novel open lower corbel tower scheme is proposed as a solution. Firstly, comprehensive finite element models are established for both the open lower corbel pylon scheme and the traditional lower continuous beam pylon scheme. These models are employed for finite element analysis to derive bending moments and displacements of the bridge pylon under various loads, including permanent, vehicle, temperature, and wind loads. Subsequently, considering internal force distribution and stiffness, a comparative assessment is made between the open lower corbel cable pylon scheme and the traditional lower continuous beam cable pylon scheme. The findings reveal that the open corbel structure bridge pylon exhibits lower transverse bending moment values under the influence of permanent load, vehicle load, temperature load, and wind load. This reduction is advantageous for mitigating the issue of significant temperature-induced secondary internal forces in the bridge pylon. Additionally, the transverse bridge stiffness of the open lower corbel cable pylon scheme is found to be on par with that of the lower continuous beam cable pylon scheme. Moreover, topology optimization of the original corbel design is accomplished using the relative density method. The computational results demonstrate that the corbel’s stress and deformation under vertical loads meet code requirements. These research findings offer valuable insights for the design and construction of similar projects.

The pylon is an essential part of lower limb prosthetics. It is usually made of titanium, aluminum, and steel. However, it is expensive and difficult to be available in developing countries, especially for children who suffer from amputation. Moreover, they constantly need new pylon pieces during close periods due to the growth and increase in the child's length. This study aims to design an adjustable pylon that can change in length to suit the increase in the length of the healthy leg of the child without the need for a new pylon and reduce the economic cost. In this study, an adjustable pylon model was designed using the CAD software (Solid work) and work to manufacture the pylon from low-cost materials (carbon fiber filament) capable of bearing the amputee's weight, and manufacturing printed parts by using additive manufacturing technical (CREALITY CR20 3D printer). The results showed that the pylon is successful in design and strength as it bears the patient's weight without any failure or buckling, and the proof that the maximum amount of stress generated is 27.8 MPa, which is far from the value of the yield stress. The design of the adjustable pylon prototype offers good strength and ability to bear the patient weight, reducing the cost and time of manufacturing. [ABSTRACT FROM AUTHOR]

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Engine pylon emergency separation is one of the key technologies in civil aircraft design, which is difficult to obtain from abroad.Domestic researches are mainly about theories and thoughts, which cannot be applied on engineering.In this paper, the research on relationship of design loads among pylon, fuse pin and wingbox is carried out based on airworthiness standards.Load determination methods for strength calculation of interface structures is proposed through scenario analysis.The results show that the engine pylon emergency separation design only needs to consider predominantly upward loads and aft loads separately.Giving reasonable relationship of design loads among pylon, fuse pin and wingbox can reduce the weight of structures.Load directions of components connecting the pylon to the wing should be determined through scenario analysis considering structural details.

This study aimed to estimate the drag and lift coefficients of the long-span bridge pylon using the finite volume method (FVM). The k-ω turbulence model was applied to analyze the behavior of wind flow around the pylon, yielding drag and lift coefficient values with an error of 0.98% compared to a previous tunnel experiment. Four recommended cross-sections were proposed to reduce drag and lift forces acting on the pylon, including concave, convex, crossing, and chamfering cross-sections. The finding indicated that drag and lift coefficient decreased for all cross-sections. Cutting edges of concave, convex, and chamfering cross-sections with a ratio ranging from 0.2 to 0.3 has the greatest impact on reducing drag coefficient, while the crossing cross-section with a cutting ratio ranging from 0.2 to 0.25 has the lowest drag coefficient. The maximum reduction in drag and lift coefficients were 23.69% and 13.14% for concave and chamfering cross-sections. Thus, cutting edges of cross-sections is an effective method to enhance the aerodynamic stability of the pylon. Additionally, we evaluated drag and lift coefficients for different wind direction angles. The angles of 0, 30, and 90 degrees resulted in the highest drag coefficient, while the angle of 0 degrees and the angle of 90 degrees resulted in the lowest and highest lift coefficient, respectively. This study not only provides recommendations for cross-sections that reduce forces acting on the pylon but also provides the intensity of this reduction through corresponding estimation equations. In conclusion, concave and chamfering cross-sections are the most effective in reducing drag and lift coefficients, or, in other words, increasing the aerodynamic stability of the pylon. [ABSTRACT FROM AUTHOR]

Cable-stayed bridges have been constructed with different type of towers (pylons) in the World, namely H-shaped, A-shaped, inverted Y-shaped, single column, diamond-shaped. More than half of the cable-stayed bridges utilised the towers with inclined legs. The dynamic response of inclined tower legs can be extremely complicated during earthquakes. Real earthquakes provide an excellent opportunity to gain insight into the performance of the towers. The present paper focuses on the real dynamic responses of inverted Y-shaped towers in long span cable-stayed bridges by using monitoring data recorded during moderate earthquakes. Nissibi cable-stayed bridge with two inverted Y-shaped towers constructed in Adıyaman, Turkey is selected for the application. Samsat (Adıyaman) earthquake with magnitude 5.5 (Mw) occurred near the bridge site. The dynamic responses of the bridge towers during the earthquake have been recorded using 3 D accelerometers. Vertical and horizontal spatial variations of the acceleration responses recorded during the earthquake at the foundation, deck and top levels of the two towers in longitudinal, transverse and vertical directions are evaluated and compared with each other. Significantly acceleration amplifications along the height of the towers and arrival time delays between the tower foundations are observed on the selected cable-stayed bridge. [ABSTRACT FROM AUTHOR]

This study aims to select the suitable density of the material according to the mechanical properties needed by the 3D-printing application in which it will be used. 3D-printed carbon fiber filaments with different printing densities have been tensile, and a fatigue test was experimented with to find the mechanical properties. Furthermore, the modulus of elasticity, yield stress, and ultimate tensile strength of the material was determined by analyzing the stress-strain curves. The result shows that the parts printed with a high infill density give better mechanical properties, more time to build the object, more strength, and heavier weight than those printed with low infill density. [ABSTRACT FROM AUTHOR]

This paper presents the results of testing and optimization of a plasma-assisted combustion scheme based on a pylon for fuel injection equipped with a plasma actuator. Electrodes were installed behind the stern of the pylon for the creation of Q-DC discharge with voltage U = 200–2500 V and current I = 3–7.5 A. The experiments were performed in the PWT-50 supersonic wind tunnel of the JIHT RAS under the following conditions: Mach number M = 2, static pressure ~200 Torr, stagnation temperature T0 = 300 K. Gaseous fuel ethylene was used and the fuel mass flow rate was 0.5–4 g/s. The pylon had a streamlined shape that prevented the formation of a stagnant zone; plasma-assisted combustion was performed under more difficult conditions compared to plasma-assisted combustion on a flat wall, where separated flows near the wall are easily formed by discharge. In this work, two new geometries of pylon equipped with electrodes were proposed and experimentally tested. A second version providing a longer discharge length demonstrates stable ignition and intense combustion in a fully discussed fuel mass flow rate. The process of ignition in a supersonic flow and flame front pulsations was described. A reduction in the energy input in comparison with the previously considered configurations of plasma-assisted combustion was also demonstrated. [ABSTRACT FROM AUTHOR]

This work introduces a collection of stone-made architectural details and decorations found in the course of archaeological research of the Golden Horde town of Azak. When analyzing the architectural decorations, the main attention was paid to the search for analogies in the regions which were part of the Azak's trade and cultural relations. The work describes the peculiarities of ornamentation, construction methods and chronological attribution of the complexes where the finds were discovered. Close cultural connections were revealed between the local masters and the builders from the Golden Horde Crimea who, in turn, adopted the traditions from Seljuk architects who moved to the peninsula in the middle of the 13th century. It became possible to identify a local tradition of stone carving with no analogies in other Golden Horde towns and neighboring regions.

The effect of air temperature on the penetration and mixing of a liquid hydrocarbon fuel injected into supersonic airflows was investigated. The supersonic air of Mach 1.8 with a total temperature in the range of 373–673 K was supplied to the test section. The liquid fuel was injected into the supersonic airflow by means of an alternating-wedge pylon with a fuel-to-air momentum flux ratio of 15. A laser sheet imaging system using Mie scattering has been used to investigate the instantaneous and ensemble-averaged characteristics of the fuel plume, the fuel/air mixing process, and fuel evaporation. As the air temperature increased, the Mie scattering signal gradually weakened due to fuel-air mixing enhancement and fuel evaporation downstream of the pylon. At an air temperature of 673 K, most of the fuel evaporated before reaching the outlet of the test section (X/d = 703). As the air temperature increased from 373 to 673 K, the total pressure loss without fuel injection decreased from 20.6 to 15.4%. In addition, the total pressure losses due to fuel injection was about 3.5% greater than that without fuel injection. As the air temperature increased, the fuel penetration height decreased. However, at the air temperatures higher than the fuel boiling temperature, the fuel jet/spray penetration heights were almost similar, showing little effect of temperature any further. [Display omitted] • The effect of air temperature on the penetration and mixing of a liquid fuel in supersonic airflows was investigated. • The Mie scattering technique was used to visualize the mixing structure of liquid fuel in supersonic airflows. • The effect of air temperature increase on the total pressure loss due to the pylon and fuel injection was investigated. [ABSTRACT FROM AUTHOR]

The aim of this study is to design a pylon with an engineering structure that gives it support and strength and manufacture a pylon characterized by low cost, lightweight, and bearing the patient's weight. This study designed two pylon models and fabricated by additive manufacturing techniques. The polylactic acid polymer is used as the filament for the 3D printing of pylons. A force plate and tensile test with finite element method simulation ANSYS software were applied to the pylons to evaluate their performance. The results showed that 3D printed pylon with Y-section has enough strength under stress and good safety factor, and the ability to bear a high patient load without buckling and exceed the requirements to become instead of the metallic prosthetic pylons. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to enhance the visual quality of artificial above-ground structures, like pylons, masts, and towers of infrastructures and facilities, through a systematic design method for their morphological and structural optimization.Design/methodology/approach: The method achieves the functional and aesthetic goals based on the application of computer-aided tools. In particular, this is achieved according to three key steps:• Morphological development of landscape-related symbolism, environment, or culture and social needs.• Topology optimization of the design concept to reduce the structural weight and its visual impact.• Engineering of the resulting optimized structure.Practical implications: As a case study, the method is used for designing electricity pylons for the coastal territory of a Mediterranean European country, such as Italy. Citizens were involved during the identification phase of a symbolic shape for the concept development and during the final assessment phase.Research limitations/implications: The engineering phase has been performed by assembling standard lattice components with welded connections. Even if the use of this truss-like structure should lead to a minimum cost, the developed structure employs an additional 15%–20% of trusses and sheet metal covers the final cost is higher than a standard lattice pylon.Findings: The result is a structure with enhanced visual quality according to the international guidelines and fully complying with mandatory and functional requirements, such as regulatory and industrial feasibility, as well as those arising from social components.Originality/value: The method shows its potential in defining a custom design for lightweight structures with enhanced visual quality regarding the critical situation discussed here. The method considers both the subjective perception of citizens and their priorities and the landscape where the structures will be installed.

This work is devoted to a theoretical study of the features of sound propagation in a lined horseshoe-shaped duct that simulates the outer duct of an aircraft engine in the presence of a pylon. As a result of this study, cases were determined in which separation of variables is allowed, that is, a direct analytical solution for eigenmodes is possible, and the form of waveguide modes is obtained. The characteristic equations of this duct are found, which are satisfied by the eigenvalues, which are the azimuthal and radial wave numbers. A study of the axial wave numbers characterizing the effectiveness of the cladding was carried out for different impedance values in the presence and absence of sound-absorbing structures on the pylon. The calculation has shown that the lining of the pylon can lead to an increase in the level of noise attenuation by 2 dB. [ABSTRACT FROM AUTHOR]

This study aimed to estimate the drag and lift coefficients of the long-span bridge pylon using the finite volume method (FVM). The k-ω turbulence model was applied to analyze the behavior of wind flow around the pylon, yielding drag and lift coefficient values with an error of 0.98% compared to a previous tunnel experiment. Four recommended cross-sections were proposed to reduce drag and lift forces acting on the pylon, including concave, convex, crossing, and chamfering cross-sections. The finding indicated that drag and lift coefficient decreased for all cross-sections. Cutting edges of concave, convex, and chamfering cross-sections with a ratio ranging from 0.2 to 0.3 has the greatest impact on reducing drag coefficient, while the crossing cross-section with a cutting ratio ranging from 0.2 to 0.25 has the lowest drag coefficient. The maximum reduction in drag and lift coefficients were 23.69% and 13.14% for concave and chamfering cross-sections. Thus, cutting edges of cross-sections is an effective method to enhance the aerodynamic stability of the pylon. Additionally, we evaluated drag and lift coefficients for different wind direction angles. The angles of 0, 30, and 90 degrees resulted in the highest drag coefficient, while the angle of 0 degrees and the angle of 90 degrees resulted in the lowest and highest lift coefficient, respectively. This study not only provides recommendations for cross-sections that reduce forces acting on the pylon but also provides the intensity of this reduction through corresponding estimation equations. In conclusion, concave and chamfering cross-sections are the most effective in reducing drag and lift coefficients, or, in other words, increasing the aerodynamic stability of the pylon.

The definition of the spatial variability of the ground motion (SVGM) is a complex and multi-parametric problem. Its effect on the seismic response of cable-stayed bridges is important, yet not entirely understood to date. This work examines the effect of the SVGM on the seismic response of cable-stayed bridges by means of the time delay of the ground motion at different supports, the loss of coherency of the seismic waves, and the incidence angle of the seismic waves. The focus herein is the effect of the SVGM on cable-stayed bridges with various configurations in terms of their length and of design parameters such as the pylon shape and the pylon–cable system configuration. The aim of this article is to provide general conclusions that are applicable to a wide range of canonical cable-stayed bridges and to contribute to the ongoing effort to interpret and predict the effect of the SVGM in long structures. This work shows that the effect of the SVGM on the seismic response of cable-stayed bridges varies depending on the pylon shape, height, and section dimensions; on the cable-system configuration; and on the response quantity of interest. Furthermore, the earthquake incidence angle defines whether the SVGM is important to the seismic response of the cable-stayed bridges. It is also confirmed that the SVGM excites vibration modes of the bridges that do not contribute to their seismic response when identical support motion is considered. [ABSTRACT FROM AUTHOR]

نقوش الصرح الثانى للملك رعمسيس الثانى فى أبيدوس يتناول البحث وصف وترجمة النصوص المدونة على جدران الصرح الثانى لمعبد الملك رعمسيس الثانى والذي شيد على مبعده 300 متر شمال غرب معبد والده ولقد شيد الَملك رعمسيس الثانى هذا المعبد خلال السنوات الأربع أو الخمس الأولى من عهده وذلك فيما عدا جدرانه الخارجية وأطلق عليه اسم «منزل ملايين السنين». وشيد المعبد من الحجر الجيرى الجيد والذي تم جلبه من المحاجر المحليه في المنطقه. وتناول البحث النقوش المسجلة على البرج الجنوبى للصرح وكذلك النقوش المسجلة على البرج الشمالى وكذلك نقوش البوابة الجرانيتية الحمراء والنقوش المسجلة على الأكتاف الداخلية للبوابة. [En] This paper deals with the inscriptions of the second pylon of king Ramesses II at Abydos. He built this temple to sanctify the three principal deities of Abydos: Osiris, Isis, and Horus, and to deify himself in it, and to be a house of a million years in which to be worshipped with religious rituals performed for him after his death.

Lower limbs are exposed to an immense amount of impact forces during walking cadence and ambulators rely on various systems to shield the musculoskeletal arrangement from external shocks that inflict injury. The work elaborates the need for the adaptive design of Regenerative effort assistive Smart Pylon (RSP) with a Smart foot adapter (SFA) and wave spring suspension mechanism to resist static and dynamic impact load of 60-100 kgs amputee and also stabilizes to ground reaction forces (GRF) without falling. Stress maximum, axial, bending, and torsional stresses were assessed for Al 6061 T6 material and the related fatigue failure criteria were evaluated. The operating stress, deflection response, and wave spring rate of the pylon unit have been calculated and the pertaining results show that the designed RSP pylon unit is safe to impact forces and more favorable for impoverished lower limb amputees and to carry out their daily activities without compromising. [ABSTRACT FROM AUTHOR]

USNC-Technologies (USNC-Tech) is an advanced nuclear company focused on developing space nuclear power and propulsion systems to enable high-impact science missions and the growth of a self-sustaining in-space economy. As a subsidiary of Ultra Safe Nuclear Corporation (USNC), USNC-Tech has leveraged the technologies and experience gains from the design, licensing, and deployment of terrestrial gas-cooled reactors for these space systems. The result is a family of reactor concepts and designs with shared technology bases able to meet near-term and long-term customer needs in the space arena. Key examples include the Pylon surface fission power reactor, the Ready 2 Demonstrate Technology On Orbit (R2DTOO) nuclear thermal propulsion reactor, and the chargeable atomic battery radioisotope heat source. [ABSTRACT FROM AUTHOR]

The aircraft industry is striving to reduce the weight of aircraft to save fuel and hence reduce total cost. New alloys and composites with properties such as low weight and high strength are continuously developed. Titanium alloys have the best strength-to-weight ratio among metals which makes them very suitable for aircraft applications. Ti-64 is the most common Titanium alloy used in aircraft. AA2099 is a 3rd generation Al-Li alloy and has the lowest density among all Aluminium alloys making it very attractive for aircraft applications. Pylons of commercial aircraft are currently made primarily with Ti-64 and this study focused on the replacement of Ti-64 with AA2099. Loading conditions, operating temperature, corrosion resistance, manufacturability and recyclability of the pylon were analysed of both Ti-64 and AA2099. Three critical scenarios were chosen for the loading conditions of the pylon. These were simulated using finite element analysis first using Ti-64 and then AA2099. From the results, it is evident that using AA2099 as the material of the pylon instead of Ti-64 offered weight savings. The operating temperature, manufacturability and recyclability also showed advantages when using AA2099 whereas corrosion factors favoured Ti-64, since AA2099 was found to be very prone to galvanic corrosion. [ABSTRACT FROM AUTHOR]

This paper studies for the first time the effect of the spatial variability of ground motions (SVGM) with large intensities on the inelastic seismic response of the pylons which are responsible for the overall structural integrity of cable-stayed bridges. The svgm is defined by the time delay of the earthquake at different supports, the loss of coherency of the seismic waves and the incidence angle of the ground motion. An extensive study is conducted on cable-stayed bridges with 'H'- and inverted 'Y'-shaped pylons and with main spans of 200, 400 and 600 m. The svgm is most detrimental to the pylon of the 200-m span bridge owing to the large stiffness of this bridge compared to its longer counterparts. The stiff configuration of the inverted 'Y'-shaped pylon makes it more susceptible against the multi-support excitation than the flexible 'H'-shaped pylon, especially in the transverse direction of the response. Finally, the earthquake incidence angle is strongly linked with the svgm and should be included in the seismic design of cable-stayed bridges. [ABSTRACT FROM AUTHOR]

The periodic monitoring of energy lines to lessen the impacts of threats and to destroy the potential risks against the power transmission lines (PTL) is highly important. The risks can involve natural causes (vegetation, landslides, trees, avalanches, storms, etc.) on the one hand and the human factor (constructions and buildings breaking the safety distance, dumping the excavated material, theft, etc.) on the other hand. In this study, an algorithm, which can automatically detect PTLs' wires and pylons using the UAV LiDAR data, is developed. Specific safety distances are also spatially analyzed and the existence of risky ground objects is examined with the help of the detected PTLs. In the newly developed algorithm, ground points are located and the low object points in vertical distance to these ground points are eliminated using the cloth simulation filtering (CSF) method. The remaining point cloud is separated into voxels of 5×5×5m in size. In the search of 26 neighbor voxels, starting from automatically determined seed voxel, final detection of wire and pylons has been determined by the algorithm of "concave hull" after their straight slopes which are fitted by height values variant and RANSAC were analyzed. The accuracy value for wires was 97.13%, the integrity value was 97.36%, the quality value was 94.63%, for the pylons the accuracy value was 70.25%, the integrity value was 94.24% and the quality value was 67.36% in the algorithm developed. Periodic applications based on the proposed approach will make it easy to monitor and maintain PTLs components (wires and pylons) without time-consuming field works. [ABSTRACT FROM AUTHOR]

Electrical pylons are frequently used by birds for perching, roosting, and nesting. These behaviors can lead to electrocutions, particularly when pylons are constructed of grounded concrete and steel crossarms, as they were in our study area near Arak, Iran. To address electrocutions of Eurasian Kestrels (Falco tinnunculus) and a variety of passerines nesting on a 20-kV distribution line, we documented construction and use of nests on pylons on a 34-km segment of power line in 2018. Following removal of nests by the electric utility operating the line, we installed nest boxes on pylons that previously supported nests, and in 2019 we documented use of those nest boxes. We predicted that after installation of nest boxes, numbers of Eurasian Kestrel nests would increase, and numbers of nests outside of nest boxes, avian electrocutions, and faults (electric current arcing from conductors to pylons) would decrease. All four predictions were validated. We documented 31 nests in 2018, including 3 Eurasian Kestrel nests. In 2019, we documented 6 nests outside of nest boxes, and 31 nests in nest boxes, including 16 Eurasian Kestrel nests. In 2018, we found 1 electrocuted Eurasian Kestrel, and 39 electrocuted passerines. In 2019, we found 3 electrocuted Eurasian Kestrels, 11 passerines, 2 Eurasian Eagle-Owls (Bubo bubo), and 1 Steppe Eagle (Aquila nipalensis). The rate of electrocutions per nest for Eurasian Kestrels decreased from 0.33 to 0.19, and the electrocution count for all birds decreased by 57.5%. Electrical faults, an indirect measure of potential avian electrocutions, decreased from 173 in 2018 to 120 in 2019. Although there is some risk that nest boxes on power poles could create ecological traps, our results suggest that in this study electrocutions and electrical faults were reduced, supporting conservation goals and electric power reliability goals while simultaneously reducing electric utilities' maintenance obligations. [ABSTRACT FROM AUTHOR]

The temple of Amun-Ra at Karnak (Luxor) experienced over 1,500 years of construction, destruction, renovation, and expansion. Here we provide a detailed survey of the current understanding of the temple’s chronological development, based primarily on published excavation reports, as well as interpretive articles and recent discoveries at the site.

The object of the study was to evaluate azolla as a substrate in the sexual propagation of two varieties of amaranth. A randomized complete block design with a factorial arrangement of 2 x 4 was used, using 2 varieties of amaranth and 4 types of substrates, this for 3 repetitions. We counted the total number of plants that are 128 per treatment therefore it is the same amount of alveoli due to a previous thinning to determine the percentage of germination in 36 plants per net plot. The number of days elapsed from sowing to the emergence of seedlings was taken into account. Azolla as a 100% substrate showed excellent results to the emergence, but for the survival of the seedling the results were not very acceptable, since the seedlings spent around 20 days began to lose vigor, because the Azolla acted as a sponge at the moment of absorbing water, which does not give good support to the seedling. The azolla with pomina did not give acceptable results for the germination of the seed, the mixture of both structures causes significant openings in the pylon, affecting the stability of the seed inside the substrate, and that is, with the wide porosity the seed goes towards the background and lose contact with sunlight, essential factor for the emergency. It was defined as the best type of substratum to S3, that is to say, the substrate elaborated with Peet moss, since it has well-marked significance ranges, being located in the first range in each of the studied factors. In the variable germination percentage, the treatment V2S3 (A. quitensis + Peet moss) obtained significance at 5% with an average of 92.29%, being the best. In terms of seedling height, the best treatment was shown in V2S3 (A. quitensis + Peet moss) with an average of 6.41cm, which determined its significance at 5%. The variable root volume was observed as the best treatment at V2S3 (A. quitensis + Peet moss) that produced plants with 0.58 mL root volume as mean and with 5% significance. The use of azolla as an amaranth propagation substrate.

This study clarifies the flow field and flame structure of a cavity flameholder with pylons in a Mach 2.8 airflow. A burned hydrogen/air gas mixture, rich in fuel, was injected in supersonic combustion experiments because self-ignition of fuel is difficult in a mainstream with low enthalpy. Experimental data were collected using the shadowgraph method, direct photography of the flame, wall pressure measurement, and OH Planer Laser-induced Fluorescence (OH-PLIF) measurement. In addition, three-dimensional numerical simulation was conducted. When one pylon was installed upstream of the jet flow, the penetration height of the jet increased, and a flame was formed in the mainstream center. When two pylons were installed at the front edge of the cavity, the flow field inside the cavity differed depending on the distance between the pylon and jet flow. The ignition and combustion of the burned-gas were suppressed at a close distance between the pylon and jet flow. For a large distance between the pylon and jet flow, the ignition and combustion of the burned-gas was enhanced. When hydrogen was injected as the main fuel from the upstream of the cavity, ignition of the main fuel was successful only for a large distance between the pylon and jet flow. [ABSTRACT FROM AUTHOR]

Сable-stayed bridge structural optimization based on linear programming and static analysis is described. Two structural schemes are proposed. Series of geometric, computational models with various boundary conditions are constructed. For modeling and analysis the finite element method was used. Based on the analysis of calculations results, the conclusions on optimization of the design are made.

The effect of structural changes on the temperature behavior of a long-span bridge pylon was examined using field-measured data and finite element (FE) analysis. Temperature behavior of the pylon could be modeled using two characteristic parameters, α and β, which reflect the influence of the variation in the ambient temperature and the sectional temperature difference, respectively. Two major structural changes namely, decrease in stiffness in the lower region of the pylon and decrease in area of the main cable were considered in the FE analyses, which showed that both α and β were affected by the structural changes. Furthermore, the two characteristic parameters could be extracted with sufficient accuracy from field-measured temperatures and tilting angle data using a system-identification technique. Consequently, the feasibility of identification of structural changes by continuous observation of temperature parameters was demonstrated. However, the tilting angle of the pylon is influenced by other loads than the temperature and therefore future studies on eliminating other loading effects (such as that owing to wind or traffic) are necessary. [ABSTRACT FROM AUTHOR]

This article is devoted to the investigation of the causes and peculiarities of high-frequency gas-dynamic self-oscillations arising in the outflow line of gas control valves. We have demonstrated that these self-oscillations result in a substantial increase in the level of dynamic loading of the control valve elements due to the occurrence of intense tonal components in the pressure fluctuation spectra in the pipeline, the vibrations of the output flange of the control valve, as well as the external noise of the whole assembly. We have provided the results of investigating the conditions for high-frequency gas-dynamic self-oscillations arising from the gas flow interaction with the control valve elements, as well as with supporting pylons of the central fairing. It is shown that an increase in the flow above a certain value of output speed (40 m/s) results in tonal components of the spectrum of pressure pulsations. We have described the measures to suppress gas-dynamic self-oscillations by means of a perforated sleeve installed in the outflow line of the control valve. Three modifications of the sleeve design have been modeled, numerical simulation of gas-dynamic processes in the control valve exhaust duct with a perforated sleeve installed has been carried out. It is shown that complete elimination of gas-dynamic self-oscillations can be made possible by installing the sleeve in the control valve exhast duct.

Cable-stayed bridges are complex structures and for their design, the traditional calculation methods are hard, even impossible to use for a global analysis. Separate analyses for the each component of the bridge in a simplified manner can be conducted, but in this case the concurrence of the elements into the structure is not taken into account, leading to errors in estimating the structural response. For these structures, the construction method and the presence of the stays, which are elements having a nonlinear behaviour, implies to consider a nonlinear staged analysis including the second order effects in order to transmit form one stage to the other the stress-strain state.

Information on height of pylon is important when planning the routes of unmanned aerial vehicles. This paper proposes a new automatic method for estimating pylon height using shadow differences between GF-2 satellite images taken at different times. Initially, the spectral distribution features and triangular shape of pylon shadows are used for shadow detection to enhance the difference from other land objects using images taken at a greater sun elevation angle. Then, the difference in the shadows of the same pylon in images taken at different times and shadow-imaging principles are used to estimate the vertical of the pylon top to avoid interference from complex land objects. Finally, the height of the pylon is approximated using the distance from the vertical projection point to the shadow point of the pylon top and sun elevation angle. GF-2 images were selected and included five pylons in the target area. The average error of the estimated height was 1.56 m, and the relative error was only 2.74%. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]