Journal articles on the topic 'Rings Design and construction'
To see the other types of publications on this topic, follow the link: Rings Design and construction.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Rings Design and construction.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Botez, Alexei, and Elena Rusu. "DESIGN ASPECTS OF INSTALLATION DEVICES OF THE SUPPORT RINGS." Journal of Engineering Science 28, no. 3 (September 2021): 51–63. http://dx.doi.org/10.52326/jes.utm.2021.28(3).03.
Full textAbstract:
The processes of manufacturing machines and appliances show a continuous tendency to increase the degree of automation. An important role in the automation of manufacturing processes is played by the constructive technologicality of the product. It is important to use a minimum number of components, which have a construction as technological as possible in terms of automation. In this context, the use of supporting rings as fasteners is welcome. The design of the installation devices of these rings requires the knowledge of their deformation forces, information that is missing in the profile literature. The authors set their goal to develop the method for calculating the forces required to deform the supporting rings with a rectangular transverse profile and their maximum allowable deformations. The calculation relationships were obtained by formalizing the supporting ring through a bar with a fixed end and studying its deformation using Mohr's integral. The article lists some types of the supporting rings used in the construction of machines and appliances, their advantages and disadvantages, aspects of their automatic installation: deformation and installation methods, precision of joint orientation, optimal design, calculation of forces required for deformation and the maximum permissible deformation value. As a result of the research carried out, recommendations were developed regarding the calculation of some constructive parameters of the devices for installing the supporting rings.
2
Hansman, Jan. "Design and construction of a shield for the 9" x 9" NaI(Tl) well-type detector." Nuclear Technology and Radiation Protection 29, no. 2 (2014): 165–69. http://dx.doi.org/10.2298/ntrp1402165h.
Full textAbstract:
This paper describes a homemade lead, 15 cm-thick, cylindrical shaped shield of a 9" x 9" NaI(Tl) gamma spectrometric well-type detector. Commercially available lead was melted into cylindrical rings. The molds for the cylindrical rings were made from hard-cooked beech wood which was pressed in a sand mold to make the final mold. After cooling, the lead rings and ring edges were sanded, transported from the foundry to the laboratory of the Department of Physics in Novi Sad, Serbia, and assembled in the detector shield. The total mass of the shield is 2622 kg. Some lines inside the shield are reduced almost 200 times and the total count rate (280 keV-3000 keV) is reduced 132.7 times.
3
Shevchenko, S. V., and O. S. Krol. "CONSTRUCTION MODIFICATION OF RADIAL THRUST ROLLER BEARINGS." Globus: technical sciences 7, no. 1(37) (February 19, 2021): 4–8. http://dx.doi.org/10.52013/2713-3079-37-1-1.
Full textAbstract:
Analytical relationships have been developed for the design of modified tapered roller bearings based on standard bearings of the 7000 type. The modification consists in replacing the rolling elements in the form of tapered rollers with a straight generatrix by concave rollers with an arc generatrix, which are in contact with the convex raceways of the rings. By calculation, the advantage of modified roller bearings in terms of service life in comparison with standard roller bearings of similar overall dimensions is shown.
4
Wang, Tan, Kun Yin, and Li Jun Dou. "Analysis and Design of the Profiled Bar Cantilever Scaffold with the Hoisting Unloading Wire Ropes." Advanced Materials Research 912-914 (April 2014): 1050–53. http://dx.doi.org/10.4028/www.scientific.net/amr.912-914.1050.
Full textAbstract:
In this paper, a model that the profiled bar cantilever scaffold with the hoisting unloading rope is created, utilizing the software sap2000.Analyzing of load-bearing of very parts of the scaffold. Calculating bearing capacity of the hoisting wire rope and the bearing capacity of hoisting rings. Put forward the design method of unloading wire rope and detailed construction requirements solution of scaffold.
5
Stadnicki, Jacek. "Optimal Design of the Cylindrical Shell of a Card Machine." Textile Research Journal 67, no. 1 (January 1997): 6–10. http://dx.doi.org/10.1177/004051759706700103.
Full textAbstract:
Deflections of a thin cylindrical shell that is used in carding machines, either as a swift or a doffer, are analyzed in this paper. The shell may have supple supports at its edges and inner strengthening in the form of rings. The task of calculating the deflections has been solved by dividing the shell into longitudinal beam elements. The optimization procedure for criteria of mass minimum or deflection minimum is used. A numerical example to define selected construction data is presented along with the results.
6
Blinov, D. S., and I. S. Chunosov. "FUNDAMENTALS OF THE DESIGN OF FUNDAL MANDRELS FOR THE INSTALLATION OF THIN-WALLED WORKPIECES. PART 1." Spravochnik. Inzhenernyi zhurnal, no. 290 (May 2021): 14–23. http://dx.doi.org/10.14489/hb.2021.05.pp.014-023.
Full textAbstract:
There are a number of problems in mechanical engineering technology. One of them is related to the installation on the machine and the previous processing of thin-walled rings, which are widely used in mechanical engineering. Due to the low bending stiffness of thin-walled rings after processing there are a large magnitude of rigidity of the form (deviation from roundness). As production experience has shown, in the conditions of mass production, it is advisable to use fungal mandrels and adjustments to reduce shape errors. They allow for a small radial gap between the holes of the ring and the fungal cam to have extended contact rings with cams along the angular coordinate. However, there are no methods for calculating the parameters of contact interaction with cams, considering a number of factors, primarily the radial clearance. Hence, it is impossible to calculate more accurately the error of the form after processing. In this paper (it is supposed to be continued), based on methods for calculating flat rings of construction mechanics of machines, a method for determining the stress-strain state of a thin-walled state is proposed, considering the contact pressure. In this case, the semiangle of contact of the ring with the fungal cam and the shape of the contact pressure plot are determined. This allows you to calculate the stress state of the thin-walled ring and the shape error when processing more accurately in a fungal mandrel, as well as reasonably assign the dimensions of the mandrel parts. Due to the exceptionally large number of calculations in the calculations according to the proposed method, it can only be implemented using a computer program, which creates great difficulties in analyzing different source data. Therefore, it is planned to rework the completed developments into an engineering calculation method with graphs in dimensionless form.
7
Wrześniak, Małgorzata. "Historia jednego motywu – rzecz o związkach biżuterii z architekturą." Załącznik Kulturoznawczy, no. 4 (2017): 221–49. http://dx.doi.org/10.21697/zk.2017.4.10.
Full textAbstract:
The hereby text is a short study on the relationship between architecture and jewellery. In the first part, it presents the history of occurrence of architectural forms in jewellery from antiquity to present day in the European culture. The second part delivers the examples of contemporary artefacts, particularly rings with microarchitecture. The analysis of the collected examples proves that architecture – its form, construction and detail − is a motive of decoration willingly used in jewellery design, often of a symbolic meaning related to the household or the temple (wedding rings, ritual rings). Nowadays, especially in the 21st century, microarchitecture in jewellery often emerges with reference to the place of origin, i.e. the famous building being, most frequently, the commemoration of a journey, able to bring back the memory of a visited city. The architectural jewellery, whose meanings and functions are the subject of the hereby study, has undergone many transformations throughout history. Even though it has transitioned from simple to complicated and decorative forms, from precious and rare to cheap and popular objects of mass production presenting the miniature replicas of buildings, the jewellery nearly always symbolises the city. Much less often the jewellery design occurs with reference to the metaphorical meanings of buildings as a representation of permanency (the tower in Alessandro Dari’s jewellery) or marital union (the house and the temple in Jewish rings).
8
Wrześniak, Małgorzata. "The Story of One Theme – on the Relationship Between Jewellery and Archi." Załącznik Kulturoznawczy ENGLISH EDITION, no. 1 (2019): 379–404. http://dx.doi.org/10.21697/zk.2019ee.01.20.
Full textAbstract:
The hereby text is a short study on the relationship between architecture and jewellery. In the first part, it presents the history of occurrence of architectural forms in jewellery from antiquity to present day in the European culture. The second part delivers the examples of contemporary artefacts, particularly rings with microarchitecture. The analysis of the collected examples proves that architecture – its form, construction and detail − is a motive of decoration willingly used in jewellery design, often of a symbolic meaning related to the household or the temple (wedding rings, ritual rings). Nowadays, especially in the 21st century, microarchitecture in jewellery often emerges with reference to the place of origin, i.e. the famous building being, most frequently, the commemoration of a journey, able to bring back the memory of a visited city. The architectural jewellery, whose meanings and functions are the subject of the hereby study, has undergone many transformations throughout history. Even though it has transitioned from simple to complicated and decorative forms, from precious and rare to cheap and popular objects of mass production presenting the miniature replicas of buildings, the jewellery nearly always symbolises the city. Much less often the jewellery design occurs with reference to the metaphorical meanings of buildings as a representation of permanency (the tower in Alessandro Dari’s jewellery) or marital union (the house and the temple in Jewish rings).
9
Seeman, Nadrian C. "DNA enables nanoscale control of the structure of matter." Quarterly Reviews of Biophysics 38, no. 4 (November 2005): 363–71. http://dx.doi.org/10.1017/s0033583505004087.
Full textAbstract:
1. Introduction 3632. Motif and sequence design 3643. Structural and topological constructions 3664. Nanomechanical devices 3675. Conclusions, applications and challenges 3706. Acknowledgments 3717. References 371Structural DNA nanotechnology consists of constructing objects, lattices and devices from branched DNA molecules. Branched DNA molecules open the way for the construction of a variety of N-connected motifs. These motifs can be joined by cohesive interactions to produce larger constructs in a bottom-up approach to nanoconstruction. The first objects produced by this approach were stick polyhedra and topological targets, such as knots and Borromean rings. These were followed by periodic arrays with programmable patterns. It is possible to exploit DNA structural transitions and sequence-specific binding to produce a variety of DNA nanomechanical devices, which include a bipedal walker and a machine that emulates the translational capabilities of the ribosome. Much of the promise of this methodology involves the use of DNA to scaffold other materials, such as biological macromolecules, nanoelectronic components, and polymers. These systems are designed to lead to improvements in crystallography, computation and the production of diverse and exotic materials.
10
Li, Hong Wei, Zhi Yuan Pan, Jing Wang, and Pan Ting Dong. "Insulation Optimization of ±1000kV DC Wall Bushing." Advanced Materials Research 1070-1072 (December 2014): 1016–20. http://dx.doi.org/10.4028/www.scientific.net/amr.1070-1072.1016.
Full textAbstract:
±UHV (Ultra-high voltage) DC (direct current) wall bushing is an important equipment of UHV DC transmission system. It plays a key role in the economic transfer, flexible allocation and safe usage of power. In this paper, the methods of improving the electric field distribution and insulation construction optimization are explored. The choice of insulation materials is discussed. Some calculations are made about how to optimize and design the capacitor core and how to optimize the parameters of grading rings. The research results would provide useful reference for further design and development of UHV DC wall bushings.
11
Orozco Lozano, Wilman, Marlen Del Socorro Fonseca-Vigoya, and Jhon Pabón-León. "Study of the Kinematics and Dynamics of the Ring Pack of a Diesel Engine by Means of the Construction of CFD Model in Conjunction with Mathematical Models." Lubricants 9, no. 12 (November 28, 2021): 116. http://dx.doi.org/10.3390/lubricants9120116.
Full textAbstract:
The present research aims to analyze the kinematic and dynamic behavior of the piston ring package. The development of the research was carried out through the development of numerical simulation by means of CFD. The analysis involves the three piston rings for the development of simulations that are closer to the real conditions of the engine since most of the investigations tend to focus on the study of the compression ring only. The simulation was reinforced by the incorporation of mathematical models, which allow determining the piston kinematics, the lubrication properties as a function of temperature, contact friction, and gas leakage. For the simulation, the CAD of the piston and the connecting rod—crankshaft mechanism was carried out, taking as a reference the geometry of a diesel engine. From the results obtained, it was possible to show that the first ring exhibits considerably greater radial and axial movement compared to the second and third piston rings. Additionally, it was shown that the first and second rings tend to maintain a negative tilt angle throughout the combustion cycle, which facilitates the advancement of the combustion gases over the piston grooves. Therefore, it is necessary to use strategies so that these rings tend to maintain a positive inclination. The analysis of the pressure conditions in the second ring are 150% and 480% higher compared to the conditions present in the third ring. Due to the above, it is necessary to focus efforts on the design of the profile of this ring. The study of energy losses showed that the combination of leakage gases and friction are responsible for a mechanical loss between 6–16%. In general, the development of the proposed methodology is a novel tool for the joint analysis of the kinematic characteristics, pressure conditions, and energy losses. In this way, integrated analysis of changes caused by piston ring designs is possible.
12
Mészáros, Ádám, Anna Székely, András Stirling, and Zoltán Novák. "Design of Trifluoroalkenyl Iodonium Salts for a Hypervalency‐Aided Alkenylation–Cyclization Strategy: Metal‐Free Construction of Aziridine Rings." Angewandte Chemie 130, no. 22 (April 30, 2018): 6753–57. http://dx.doi.org/10.1002/ange.201802347.
Full text
13
Mészáros, Ádám, Anna Székely, András Stirling, and Zoltán Novák. "Design of Trifluoroalkenyl Iodonium Salts for a Hypervalency‐Aided Alkenylation–Cyclization Strategy: Metal‐Free Construction of Aziridine Rings." Angewandte Chemie International Edition 57, no. 22 (May 28, 2018): 6643–47. http://dx.doi.org/10.1002/anie.201802347.
Full text
14
SARAPAT, N., T. D. FRANK, and P. P. YUPAPIN. "CONJUGATE MIRROR DESIGN AND SIMULATION USING A NONLINEAR COUPLING MICRORING CIRCUIT." Journal of Nonlinear Optical Physics & Materials 22, no. 03 (September 2013): 1350024. http://dx.doi.org/10.1142/s0218863513500240.
Full textAbstract:
This paper presents the use of a nonlinear microring resonator device known as a modified add-drop filter for small scale conjugate mirror, which is a basic device for 3D image construction and reconstruction system. It can also be useful for real time 3D image display applications. By using the modified add-drop filter, the 3D image can be constructed and reconstructed within the microring circuit. In this circuit, the object and reference beams can be formed by the reflected signals from through and drop ports of the add-drop filter respectively, where the conjugate mirror concept is obtained by the nonlinear coupling effects via the two nonlinear side rings, in which the four-wave mixing of those signals can be introduced. Finally, the interference of those two beams can be constructed and seen by the whispering gallery mode (WGM) at the center ring, while the interference signals can be seen by the add port output. The WGMs of waves are simulated and discussed, where the 3D image construction and reconstruction can be seen by using the microring circuit as the conjugate mirror, in which the use of large volume display using a new type of conjugate mirror can be realized.
15
Regassa, Yohannes, Hirpa G. Lemu, Belete Sirabizuh, and Samuel Rahimeto. "Studies on the Geometrical Design of Spider Webs for Reinforced Composite Structures." Journal of Composites Science 5, no. 2 (February 14, 2021): 57. http://dx.doi.org/10.3390/jcs5020057.
Full textAbstract:
Spider silk is an astonishingly tough biomaterial that consists almost entirely of large proteins. Studying the secrets behind the high strength nature of spider webs is very challenging due to their miniature size. In spite of their complex nature, researchers have always been inspired to mimic Nature for developing new products or enhancing the performance of existing technologies. Accordingly, the spider web can be taken as a model for optimal fiber orientation for composite materials to be used in critical structural applications. In this study an attempt is made to analyze the geometrical characteristics of the web construction building units such as spirals and radials. As a measurement tool, we have used a developed MATLAB algorithm code for measuring the node to node of rings and radials angle of orientation. Spider web image samples were collected randomly from an ecological niche with black background sample collection tools. The study shows that the radial angle of orientation is 12.7 degrees with 5 mm distance for the spirals’ mesh size. The extracted geometrical numeric values from the spider web show moderately skewed statistical data. The study sheds light on spider web utilization to develop an optimized fiber orientation reinforced composite structure for constructing, for instance, shell structures, pressure vessels and fuselage cones for the aviation industry.
16
Eriksson, Mikael, J. Friso van der Veen, and Christoph Quitmann. "Diffraction-limited storage rings – a window to the science of tomorrow." Journal of Synchrotron Radiation 21, no. 5 (August 31, 2014): 837–42. http://dx.doi.org/10.1107/s1600577514019286.
Full textAbstract:
This article summarizes the contributions in this special issue on Diffraction-Limited Storage Rings. It analyses the progress in accelerator technology enabling a significant increase in brightness and coherent fraction of the X-ray light provided by storage rings. With MAX IV and Sirius there are two facilities under construction that already exploit these advantages. Several other projects are in the design stage and these will probably enhance the performance further. To translate the progress in light source quality into new science requires similar progress in aspects such as optics, beamline technology, detectors and data analysis. The quality of new science will be limited by the weakest component in this value chain. Breakthroughs can be expected in high-resolution imaging, microscopy and spectroscopy. These techniques are relevant for many fields of science; for example, for the fundamental understanding of the properties of correlated electron materials, the development and characterization of materials for data and energy storage, environmental applications and bio-medicine.
17
Shevchenko, Serhii. "ANALYSIS OF THE IMPACT OF SPECIAL CONSTRUCTIONS OF GAP SEALS ON THE DYNAMICS OF CENTRIFUGAL MACHINES." ScienceRise, no. 5 (November 11, 2020): 3–13. http://dx.doi.org/10.21303/2313-8416.2020.001485.
Full textAbstract:
The object of research: the influence of the design features of special gap seals on the dynamic characteristics of centrifugal machines.
Investigated problem: harmonization of the consumption and dynamic characteristics of the seals of the rotors of high-speed machines by applying special design methods.
Main scientific results: The mechanism and operating conditions of seals with floating rings are described. It is determined that the most effective from the point of view of dynamic characteristics is the variant of the semi-movable ring. Expressions for determining the conditions of angular and radial immobility of a floating ring are obtained. The design options for deformable gap seals, including deformable floating rings, deformable interwheel seals and seals with an axially movable deformable sleeve, have been investigated. The scope of their application for unique machines with high requirements for tightness and vibration reliability has been determined. Variants of the design of labyrinth seals have been investigated. The analysis shows that the dynamic properties of labyrinth seals significantly depend on the relative position of the ridges. Overlapping ridged seals have the worst dynamic performance of the labyrinth seal designs. The honeycomb seal has more favorable dynamic properties, and the well seal has the best combination of consumption and dynamic characteristics. The dynamic characteristics are especially important for the seals of high-speed rotors of centrifugal machines.
The area of practical use of the research results: Enterprises that manufacture centrifugal machines: pumps and compressors.
Innovative technological product: a methodology for the selection, design and calculation of special designs of gap seals with optimization of dynamic and flow characteristics.
Scope of application of the innovative technological product: The obtained research results will be useful in the design and manufacture of centrifugal pumps and compressors for any parameters.
18
Rizal, M., J. A. Ghani, Husni ., and Husaini . "Design and construction of a strain gauge-based dynamometer for a 3-axis cutting force measurement in turning process." Journal of Mechanical Engineering and Sciences 12, no. 4 (December 27, 2018): 4072–87. http://dx.doi.org/10.15282/jmes.12.4.2018.07.0353.
Full textAbstract:
The cutting force is the most significant information in machining processes for the cutting parameter and tool geometry optimization, machine tool design, machinability testing of new materials and tool condition monitoring systems. This paper develops a strain gauge-based dynamometer for a 3-axis cutting force measurement in turning process. The octagonal rings are utilized as force transducer to develop strain gauge-based dynamometer to measure the cutting force acting on the tip of the tool. A novel geometrical design of the dynamometer structure allowed the standard tool shank of the turning operation to be easily changed without altering the sensor system. The developed dynamometer can perform the cutting force measurement up to 2.9 kN and has a dynamic response of about 766 Hz. The sensitivities were found approximately in the range of 31.3x10-3 – 172.4x10-3 mV/N and it has a low cross-sensitivity error of below 0.87%. This paper is focus on geometrical design, mathematical and FEM analyses which are significant role in force sensor developed and present an application of low cost sensing method in turning process.
19
Md Ghazaly, Mariam, Yeo Chin Kiat, Chong Shin Horng, Norhaslinda Hasim, Zulkeflee Abdullah, and Nurdiana Nordin. "TUBULAR LINEAR SWITCHED RELUCTANCE ACTUATOR: DESIGN AND CHARACTERIZATION." Jurnal Teknologi 84, no. 5 (July 26, 2022): 117–29. http://dx.doi.org/10.11113/jurnalteknologi.v84.17902.
Full textAbstract:
Linear electromagnetic actuator is receiving significant attention due to recent advances in power electronics and modern control methods. This research proposes a three-phase tubular linear switched reluctance actuator (LSRA) for application in the semiconductor fabrication industry. The tubular LSRA has a robust construction, low manufacturing and maintenance cost, good fault tolerance capability, and high reliability in a harsh environment, making it an attractive alternative to a permanent magnet linear actuator. However, the tubular LSRA has a long mover, which increases the possibility of the mover deforming during fabrication. So, a new mover design is proposed to overcome the problem. The proposed mover design allows the traveling distance of the actuator to be modified by adding or removing the rings without changing the shaft. The tubular LSRA prototype is fabricated according to the optimized design. To drive the tubular LSRA, a appropriate switching algorithm method are used to provide the correct switching signal. This method is straightforward, while no extensive knowledge of power electronic converter is required. The developed tubular LSRA can generate a maximum static force of 0.65N. Through the open-loop reciprocating motion, the dynamic responses of the tubular LSRA can achieve a maximum velocity of 210mm/s and maximum acceleration of 8m/s2, which are in the performance range for precision mechanism.
20
Han, HongJu, JiPing Guo, JiJin Zhang, and Yuan Sun. "Technical Advances of Temporary Facilities for the Failure Prevention of Large-Span Cantilever Casting Construction of Mountainous Concrete Box-Type Arch Bridges." Advances in Civil Engineering 2020 (February 6, 2020): 1–20. http://dx.doi.org/10.1155/2020/6412613.
Full textAbstract:
In the highways of mountainous areas, the erection of the large-span reinforced concrete box-type arch bridges using the cantilever casting method has unique advantages due to its adaptability to those environments. However, what prevents engineers from choosing this design in practice is that, the efficiency, cost, and safety problems resulting from the defects of the temporary facilities, which are due to the span increase, may immediately make the scheme less attractive. To fully consider the merits of this bridge type, new techniques of the temporary facilities are developed. A new form traveler based on the feathers of such arch rings is invented to promote erection efficacy; this new form further facilitates the technical upgrades of the buckle-anchor system monitoring-control and temporary prestressing design, which together eliminate the difficulties brought by the span increase. The inverted-type triangle traveler composed of tiled main truss structures, with the walking hook and anchor tie rod detached, is used to achieve space adaptability, light weight and modularization. The semiautomatic deviation-rectifying system, which combines the technologies of real-time data collection of the buckle pylon deviations and automatic synchronized tensioning, is developed to ensure the safety of the buckle-anchor system. The temporary short prestressed tendons are designed for control of the arch ring tensile stresses. The effectiveness of the technical upgrades has been demonstrated in the construction application of the Shatuo Bridge in Guizhou, China, which provides a promising alternative for the construction of large-span box-type arch rings of concrete arch bridges with a low cost, high efficiency, and high safety assurance.
21
Zheng, Guoping, and Jurij Karlovsek. "Study on the Universal Tapered Segmental Ring Assembly Simulation Algorithm and Deviation Assessment: A Case Study on Metro Line Tunnel." Advances in Civil Engineering 2021 (December 8, 2021): 1–14. http://dx.doi.org/10.1155/2021/9975848.
Full textAbstract:
Universal tapered segmental ring system has been adopted to assemble tangent and curve line elements into the shield tunnels through the relative rotation of the adjacent front and rear rings, which simplifies the formwork design, demonstrates strong universality, and is easy for quality assurance. To evaluate the position deviation caused by the taper value and propose the assembly scheme for the contractor, this article developed the universal tapered segmental ring assembly simulation technology. Firstly, the assembly procedure of the universal tapered segmental ring system both in normal case and in special case is introduced, including the interval tunnel of special rings and actual engineering that needs deviation correction. Secondly, relevant core algorithms are introduced in detail, including the coordinate position algorithm of horizontal and vertical curves and computer graphic algorithm of spatial point rotating around any axis. Finally, this article takes a background metro line tunnel as a case to validate the algorithm and illustrate the assessment methodology of universal tapered segmental ring assembly accuracy. The sections with maximum deviation are found as an alert ahead of the shield advancing. In conclusion, the algorithms and methodology proposed in this article illustrate the excellent suitability and robustness in shield tunnels adopting a universal tapered segmental ring system in the stage of both design and construction.
22
GAO, D. Y., A. V. KELAREV, and J. L. YEARWOOD. "OPTIMIZATION OF MATRIX SEMIRINGS FOR CLASSIFICATION SYSTEMS." Bulletin of the Australian Mathematical Society 84, no. 3 (October 4, 2011): 492–503. http://dx.doi.org/10.1017/s0004972711002802.
Full textAbstract:
AbstractThe max-plus algebra is well known and has useful applications in the investigation of discrete event systems and affine equations. Structural matrix rings have been considered by many authors too. This article introduces more general structural matrix semirings, which include all matrix semirings over the max-plus algebra. We investigate properties of ideals in this construction motivated by applications to the design of centroid-based classification systems, or classifiers, as well as multiple classifiers combining several initial classifiers. The first main theorem of this paper shows that structural matrix semirings possess convenient visible generating sets for ideals. Our second main theorem uses two special sets to determine the weights of all ideals and describe all matrix ideals with the largest possible weight, which are optimal for the design of classification systems.
23
Gierz, Łukasz, and Piotr Markowski. "The Effect of the Distribution Head Tilt and Diffuser Variants on the Evenness of Sowing Rye and Oat Seeds with a Pneumatic Seed Drill." Materials 13, no. 13 (July 6, 2020): 3000. http://dx.doi.org/10.3390/ma13133000.
Full textAbstract:
Due to the sustainable development of agriculture machines with large working widths of 4–6 m or even 9–12 m are increasingly often used for agrotechnical operations. The sowing machinery whose working widths are much bigger than the width of the seed box is equipped with a pneumatic system for transporting seeds from the seed box to coulters. One of the structural elements that affect the sowing accuracy in such seed drills is the distribution head with a diffuser. This article is about research on the influence of the distribution head deviation from the vertical position and constructional variants of the diffuser (the number of diffusion rings and the configuration of their position in the diffuser pipe, which is the distance between them) on the accuracy of distribution of a stream of rye and oat seeds (a seed-and-air stream), which differ in physical characteristics. The main elements, i.e., the innovative stream distributor in the head and the diffusion rings were made using an original design and the rapid prototyping method. The research proved that a change of 0–10° in the angle of the distribution head deviation from the vertical position significantly affected the sowing quality of oat seeds only. The position (density) of the diffusion rings in the lower section of the diffuser (near the supply elbow) was the most effective for both oat and rye seeds, where the average values of the coefficient of variation were 5.31% and 4.62%, respectively. The research results can be used to redesign the construction of the diffuser of the seed drill distribution head so as to reduce the resistance of transport of the seed-and-air mixture in order to improve seed sowing evenness.
24
Abdulnabi, Saif, and Mohammed Abbas. "Design an All-Optical Combinational Logic Circuits Based on Nano-Ring Insulator-Metal-Insulator Plasmonic Waveguides." Photonics 6, no. 1 (March 19, 2019): 30. http://dx.doi.org/10.3390/photonics6010030.
Full textAbstract:
In this paper, we propose, analyze and simulate a new configuration to simulate all-optical combinational logic functions based on Nano-rings insulator-metal-insulator (IMI) plasmonic waveguides. We used Finite Element Method (FEM) to analyze the proposed plasmonic combinational logic functions. The analyzed combinational logic functions are Half-Adder, Full-Adder, Half-Subtractor, and Comparator One-Bit. The operation principle of these combinational logic functions is based on the constructive and destructive interferences between the input signal(s) and control signal. Numerical simulations show that a transmission threshold exists (0.25) which allows all proposed four plasmonic combinational logic functions to be achieved in one structure. As a result, the transmission threshold value measures the performance of the proposed plasmonic combinational logic functions. We use the same structure with the same dimensions at 1550 nm wavelength for all proposed plasmonic combinational logic functions. The proposed all-optical combinational logic functions structure contributes significantly to photonic integrated circuits construction and all-optical signal processing nano-circuits.
25
Dziob, Daniel, Jakub Ramian, Jan Ramian, Bartosz Lisowski, and Jadwiga Laska. "Design and Construction of a Chamber Enabling the Observation of Living Cells in the Field of a Constant Magnetic Force." Cells 10, no. 12 (November 28, 2021): 3339. http://dx.doi.org/10.3390/cells10123339.
Full textAbstract:
The aim of the work was to design and construct a microscopic stage that enables the observation of biological cells in a magnetic field with a constant magnetic force. Regarding the requirements for biological observations in the magnetic field, construction was based on the standard automatic stage of an optical microscope ZEISS Axio Observer, and the main challenge was to design a set of magnets which were the source of a field in which the magnetic force was constant in the observation zone. Another challenge was to design a magnet arrangement producing a weak magnetic field to manipulate the cells without harming them. The Halbach array of magnets was constructed using permanent cubic neodymium magnets mounted on a 3D printed polymer ring. Four sets of magnets were used, differing in their dimensions, namely, 20, 15, 12, and 10 mm. The polymer rings were designed to resist magnetic forces and to keep their shape undisturbed when working under biological conditions. To check the usability of the constructs, experiments with magnetic microparticles were executed. Magnetic microparticles were placed under the microscope and their movement was observed to find the acting magnetic force.
26
Zhang, Yi, Zaiqian Chen, Duoxian Wu, Hao Yan, Qiao He, and Lei Wang. "Analysis on Sealing Performance for a New Type of Rubber Olecranon-Shaped Sealing Ring in Pipe Jacking Joint." Advances in Civil Engineering 2022 (July 30, 2022): 1–30. http://dx.doi.org/10.1155/2022/2811809.
Full textAbstract:
To address the easy damage of rubber sealing rings for pipe joints used in China’s first rock pipe jacking project, the launch of research concerning the optimization design of rubber ring structure was decided. However, modification based on the existing production mold was required, to prevent the construction period and cost from exceeding limits. Utilizing the optimization experience, the stress and waterproof property variations of rubber ring before and after optimization during the pipe translation and deflection were initially analyzed via the ADINA software. Meanwhile, the correct orientation of the ring optimization criteria was confirmed through the field test. Next, the effects of key structural parameters on the contact length and maximum contact pressure of rubber ring were quantified, thereby obtaining the sensitivity correlations between five key parameters of ring optimization to further establish the criteria for rubber ring optimization. The findings of this study offer safe construction suggestions for pipe jacking projects.
27
Yang, Song, Rui Dai, Zubin Ai, Xiaochang Li, Chao Zhang, and Xin Huang. "Analytical Solutions for the Mechanical Responses of Shallow Double-Arched Tunnel Subjected to Symmetric Loads." Advances in Civil Engineering 2021 (April 25, 2021): 1–33. http://dx.doi.org/10.1155/2021/8867536.
Full textAbstract:
Double-arched tunnel is a special kind of tunnel structure which is widely adopted for shallow rock tunnels. The internal forces within a double-arched tunnel are difficult to be determined due to its special geometry and complex interactions with surrounding rock masses. This paper presents a set of analytical solutions for determining the internal forces within the lining structure of shallow double-arched tunnel subjected to symmetric external loads. The double-arched tunnel is decomposed into three main parts, i.e., the arch rings, the side walls, and the middle wall. The force method and the elastic foundation beam model are employed for the arch rings and the side walls, respectively, while the middle wall is treated as a cantilever beam fixed at the bottom. Analytical solutions for the internal forces of the three parts are derived separately, which are continuous at the conjunctions of different parts. The derived analytical solutions are verified by comparing with the FEM simulation results. Finally, parametric studies are performed to investigate the influences of burial depth, elastic resistance coefficient, opening angle, and tunnel span on the internal forces based on which some recommendations are provided for the construction and design of the double-arched tunnels. The derived analytical solutions provide fast estimations for the internal forces and deformation of the double-arched lining structures, which will be a useful tool for design optimization.
28
Möller, Johannes, Michael Sprung, Anders Madsen, and Christian Gutt. "X-ray photon correlation spectroscopy of protein dynamics at nearly diffraction-limited storage rings." IUCrJ 6, no. 5 (July 11, 2019): 794–803. http://dx.doi.org/10.1107/s2052252519008273.
Full textAbstract:
This study explores the possibility of measuring the dynamics of proteins in solution using X-ray photon correlation spectroscopy (XPCS) at nearly diffraction-limited storage rings (DLSRs). We calculate the signal-to-noise ratio (SNR) of XPCS experiments from a concentrated lysozyme solution at the length scale of the hydrodynamic radius of the protein molecule. We take into account limitations given by the critical X-ray dose and find expressions for the SNR as a function of beam size, sample-to-detector distance and photon energy. Specifically, we show that the combined increase in coherent flux and coherence lengths at the DLSR PETRA IV yields an increase in SNR of more than one order of magnitude. The resulting SNR values indicate that XPCS experiments of biological macromolecules on nanometre length scales will become feasible with the advent of a new generation of synchrotron sources. Our findings provide valuable input for the design and construction of future XPCS beamlines at DLSRs.
29
Ecker, Alexander, and Harald Unterweger. "Bemessungsmodell für Schubringe von Druckrohrleitungen und Druckschächten - Teil 1/Design model for thrust rings of penstock and pressure conduits, Part 1." Bauingenieur 90, no. 10 (2015): 478–88. http://dx.doi.org/10.37544/0005-6650-2015-10-68.
Full textAbstract:
Innerhalb eines kürzlich fertiggestellten Forschungsprojektes wurde das Trag- und Verformungsverhalten von Schubringen mit Rechteckquerschnitt zur Übertragung von Rohrlängskräften im Detail untersucht. Dabei erfolgten auch Versuche an Rohren mit kleinerem Durchmesser, die zur Kalibrierung von FEM-Modellen dienten, um dann Schubringe mit baupraktischen Abmessungen zu untersuchen. Auf Basis einer Parameterstudie für baupraktische Fälle wurde ein vollständiges Bemessungsmodell für die Handrechnung entwickelt. Dieses Bemessungsmodell, das nachfolgend vorgestellt wird, beinhaltet Steifigkeit, Grenztragfähigkeit und Spannungsverteilungen im elastischen Bereich. Darüber hinaus wird auf das Zusammenwirken mehrerer Schubringe eingegangen sowie eine daraus abgeleitete einfache Bemessungsregel vorgestellt, die es erlaubt die Beanspruchung des höchst beanspruchten Schubringes einfach zu ermitteln. Ergänzend wird – in Teil 2 des Beitrags –- ein Beispiel dargestellt, um das komplexe Tragverhalten am Schubring darzustellen und damit den Hintergrund zum Bemessungsmodell aufzuzeigen.
30
Ecker, Alexander, and Harald Unterweger. "Bemessungsmodell für Schubringe von Druckrohrleitungen und Druckschächten - Teil 2/Design model for thrust rings of penstock and pressure conduits, Part 2." Bauingenieur 90, no. 11 (2015): 509–14. http://dx.doi.org/10.37544/0005-6650-2015-11-39.
Full textAbstract:
Innerhalb eines kürzlich fertiggestellten Forschungsprojektes wurde das Trag- und Verformungsverhalten von Schubringen mit Rechteckquerschnitt zur Übertragung von Rohrlängskräften im Detail untersucht. Dabei erfolgten auch Versuche an Rohren mit kleinerem Durchmesser, die zur Kalibrierung von FEM-Modellen dienten, um dann Schubringe mit baupraktischen Abmessungen zu untersuchen. Auf Basis einer Parameterstudie für baupraktische Fälle wurde ein vollständiges Bemessungsmodell für die Handrechnung entwickelt. Dieses Bemessungsmodell, das in Teil 1des Beitrags vorgestellt wurde, beinhaltet Steifigkeit, Grenztragfähigkeit und Spannungsverteilungen im elastischen Bereich. Darüber hinaus wurde auf das Zusammenwirken mehrerer Schubringe eingegangen sowie eine daraus abgeleitete einfache Bemessungsregel vorgestellt, die es erlaubt die Beanspruchung des höchst beanspruchten Schubringes einfach zu ermitteln. Ergänzend wird nun in Teil 2 des Beitrags ein Beispiel dargestellt, um das komplexe Tragverhalten am Schubring darzustellen und damit den Hintergrund zum Bemessungsmodell aufzuzeigen.
31
Tavares, Pedro F., Simon C. Leemann, Magnus Sjöström, and Åke Andersson. "The MAX IV storage ring project." Journal of Synchrotron Radiation 21, no. 5 (August 27, 2014): 862–77. http://dx.doi.org/10.1107/s1600577514011503.
Full textAbstract:
The MAX IV facility, currently under construction in Lund, Sweden, features two electron storage rings operated at 3 GeV and 1.5 GeV and optimized for the hard X-ray and soft X-ray/VUV spectral ranges, respectively. A 3 GeV linear accelerator serves as a full-energy injector into both rings as well as a driver for a short-pulse facility, in which undulators produce X-ray pulses as short as 100 fs. The 3 GeV ring employs a multibend achromat (MBA) lattice to achieve, in a relatively short circumference of 528 m, a bare lattice emittance of 0.33 nm rad, which reduces to 0.2 nm rad as insertion devices are added. The engineering implementation of the MBA lattice raises several technological problems. The large number of strong magnets per achromat calls for a compact design featuring small-gap combined-function magnets grouped into cells and sharing a common iron yoke. The small apertures lead to a low-conductance vacuum chamber design that relies on the chamber itself as a distributed copper absorber for the heat deposited by synchrotron radiation, while non-evaporable getter (NEG) coating provides for reduced photodesorption yields and distributed pumping. Finally, a low main frequency (100 MHz) is chosen for the RF system yielding long bunches, which are further elongated by passively operated third-harmonic Landau cavities, thus alleviating collective effects, both coherent (e.g.resistive wall instabilities) and incoherent (intrabeam scattering). In this paper, we focus on the MAX IV 3 GeV ring and present the lattice design as well as the engineering solutions to the challenges inherent to such a design. As the first realisation of a light source based on the MBA concept, the MAX IV 3 GeV ring offers an opportunity for validation of concepts that are likely to be essential ingredients of future diffraction-limited light sources.
32
Atanov, N., V. Baranov, L. Borrel, C. Bloise, J. Budagov, S. Ceravolo, F. Cervelli, et al. "Development and construction status of the Mu2e electromagnetic calorimeter mechanical structures." Journal of Instrumentation 17, no. 10 (October 27, 2022): C10021. http://dx.doi.org/10.1088/1748-0221/17/10/c10021.
Full textAbstract:
Abstract The Mu2e experiment at Fermilab will search for the CLFV neutrino-less coherent conversion of a muon into an electron in the field of an aluminum nucleus. The observation of this process would be the evidence of physics beyond the Standard Model. Mu2e comprises a straw-tracker, an electromagnetic calorimeter and an external veto for cosmic rays. The calorimeter provides electron identification, a fast trigger and aids track reconstruction. It is a state-of-the-art crystal calorimeter and employs 1340 pure CsI crystals readout by UV-extended SiPM and fast electronics. The design consists of two identical annular disks positioned at the relative distance of 70 cm downstream the target.The hostile Mu2e conditions (total ionizing dose of 12 krad and a neutron fluence of 5 × 1010 n/cm2 @ 1 MeVeq (Si)/y, 1 T magnetic field and vacuum level of 10−4 Torr) posed tight constraints on the mechanical structures and materials choice. The support structure of the two crystal matrices employs two aluminum hollow rings and parts made of open-cell vacuum-compatible carbon fiber. SiPMs and front-end electronics for each crystal are assembled in one mechanical unit inserted in a machined copper holder. The units are supported by a plate made of vacuum-compatible material. The plate integrates the cooling system made of a network of copper lines flowing a low temperature fluid and placed in thermal contact with the copper holders. The DAQ is hosted in aluminum crates positioned on the lateral surface of the disks. The crates also integrate the DAQ electronics cooling system. We review the constraints on the calorimeter structures design, the development of all the structural components, including the simulations that have determined the materials and technological choices and the specifications of the cooling station, components production and quality assurance tests, the procedures for detector assembly, transportation and installation in the experimental area.
33
Kaveh, Ali, Masoud Rezaei, and MR Shiravand. "Optimal design of nonlinear large-scale suspendome using cascade optimization." International Journal of Space Structures 33, no. 1 (October 23, 2017): 3–18. http://dx.doi.org/10.1177/0266351117736649.
Full textAbstract:
Large-scale suspendomes are elegant architectural structures which cover a vast area with no interrupting columns in the middle. These domes have attractive shapes which are also economical. Domes are built in a wide variety of forms. In this article, an algorithm is developed for optimum design of domes considering the topology, geometry, and size of member section using the cascade-enhanced colliding bodies optimization method. In large-scale space steel structures, a large number of design variables are involved. The idea of cascade optimization allows a single optimization problem to be tackled in a number of successive autonomous optimization stages. The variables are the optimum height of crown and tubular sections of these domes, the initial strain, the length of the struts, and the cross-sectional areas of the cables in the tensegrity system of domes. The number of joints in each ring and the number of rings are considered for topology optimization of ribbed and Schwedler domes. Weight of the dome is taken as the objective function for minimization. A simple procedure is defined to determine the configuration of the domes. The design constraints are considered according to the provisions of Load and Resistance Factor Design–American Institute of Steel Constitution. In order to investigate the efficiency of the presented method, a large-scale suspendome with more than 2266 members is investigated. Numerical results show that the utilized method is an efficient tool for optimal design of large-scale domes. Additionally, in this article, a topology and geometry optimization for two common ribbed and Schwedler domes are performed to find their optimum graphs considering various spans.
34
Shi, Tan-Hao, Shuo Tong, Lei Jiao, and Mei-Xiang Wang. "A Theoretical Study on the Macrocyclic Strain of Zigzag Molecular Belts." Organic Materials 02, no. 04 (October 2020): 300–305. http://dx.doi.org/10.1055/s-0040-1718934.
Full textAbstract:
Zigzag molecular belts have captured the imagination of scientists for over a half century because of their aesthetically appealing structures and tantalizing properties. One of the formidable challenges in synthesis is to circumvent the energy accumulated in the construction of strained structures. Reported herein is our theoretical study to quantify the molecular strain energies. A general exponential function equation E strain = a·n·e −n/b was obtained to estimate strain energies of both conjugated and partially hydrogenated hydrocarbon belts and their heteroatom-embedded analogs. The deformation of aromatic rings from planarity was revealed to contribute dominantly to the high strain energies. The method enabled the convenient quantification of the energetics of aromatization processes from partially hydrogenated double-stranded macrocycles, and facilitated the design and optimization of practical routes to synthesize the long-awaited zigzag molecular belts.
35
Klyuyev, О., A. Sadovoi, and Y. Sokhina. "CONSTRUCTION OF ROTOR ANGLE IDENTIFIER IN VECTOR CONTROL SYSTEMS OF DOUBLE FEED MACHINES." Collection of scholarly papers of Dniprovsk State Technical University (Technical Sciences) 2, no. 39 (December 21, 2021): 74–81. http://dx.doi.org/10.31319/2519-2884.39.2021.9.
Full textAbstract:
In asynchronous electric drives with vector control on the rotor, it is necessary to calculate the value of the sine and cosine of the angle of rotation of the rotor relative to the stator to form control actions. When using angle sensors, complex structural tasks can arise — placement and reliable mounting of the sensor on the shaft and, accordingly, the task of the overall layout of the unit. For high-power machines, the tasks of developing and creating the design of the sensor itself arise. If serial rotor angular position sensors can be used, the task of placing and mounting the sensor is no less difficult. In these cases it is necessary to deduce the second end of a shaft from the case of the engine with contact rings that complicates its design. Therefore, the urgent need to create more reliable electric drives with vector control systems on the rotor is the synthesis of identifiers of the angle of rotation of the rotor.
Identifiers are known whose calculation algorithms are based on determining the projections of the flow coupling vectors. In the work with the use of coordinate transducers of projections of stator or rotor current vectors and equations of electromagnetic circuits of an asynchronous machine, the synthesis and subsequent analysis of the properties of the rotor position angle identifier in vector control systems of dual power machines is performed. New equations of the identifier of flux couplings are received, its stability is investigated and on conditions of stability types of electric drives in which it is possible to apply the offered identifier are defined. The stability of the vector control system and sufficient identification accuracy when using the proposed equations and functions are confirmed by the method of mathematical modeling of the recommended electric drive systems in different operating modes.
36
Furukawa, K., M. Akemoto, D. Arakawa, Y. Arakida, Y. Bando, H. Ego, Y. Enomoto, et al. "Achievement of 200,000 hours of operation at KEK 7-GeV electron 4-GeV positron injector linac." Journal of Physics: Conference Series 2420, no. 1 (January 1, 2023): 012021. http://dx.doi.org/10.1088/1742-6596/2420/1/012021.
Full textAbstract:
Abstract KEK electron positron injector LINAC initiated the injection operation into Photon Factory (PF) light source in 1982. Since then for 39 years, it has served for multiple projects, namely, TRISTAN, PF-AR, KEKB, and SuperKEKB. Its total operation time has accumulated 200 thousand hours on May 7, 2020. We are extremely proud of the achievement following continuous efforts by our seniors. The construction of the injector LINAC started in 1978, and it was commissioned for PF with 2.5 GeV electron in 1982. In parallel, the positron generator linac was constructed for the TRISTAN collider project. The slow positron facility was also commissioned in 1992. After the KEKB asymmetric-energy collider project was commissioned in 1998 with direct energy injections, the techniques such as two-bunch acceleration and simultaneous injection were developed. As the soft structure design of the LINAC was too weak against the great east Japan earthquake, it took three years to recover. Then the construction and commissioning for the SuperKEKB project went on, and the simultaneous top-up injection into four storage rings contributes to the both elementary particle physics and photon science.
37
Tang, Jingyu. "Rapid Cycling Synchrotrons and Accumulator Rings for High-Intensity Hadron Beams." Reviews of Accelerator Science and Technology 06 (January 2013): 143–69. http://dx.doi.org/10.1142/s1793626813300077.
Full textAbstract:
Boosted by the needs in high-energy physics and nuclear physics and also multidisciplinary applications, high-intensity proton synchrotrons and accumulator rings have been developed quickly around the world over the last 30 years. New projects and plans are proposed with even higher beam power. The proton beam power has increased from less than 10 kW in the 1970s to about 1 MW level today, and the required beam power in the coming decade is a few MW. This article reviews the achievements in designing and constructing rapid cycling synchrotrons (RCSs) and accumulator rings (ARs) and the future development trends, principally on proton beams but also including heavy ion beams. It presents the evolution of RCS and AR machines, today's design philosophy, relevant accelerator physics, and also state-of-the-art accelerator technology.
38
Harte, Reinhard, Martin Graffmann, and Wilfried B. Krätzig. "Optimization of Solar Updraft Chimneys by Nonlinear Response Analysis." Applied Mechanics and Materials 283 (January 2013): 25–34. http://dx.doi.org/10.4028/www.scientific.net/amm.283.25.
Full textAbstract:
Solar updraft chimneys (SUCs) form as engines of solar updraft power plants tower-like shell structures of extreme height with rather thin shell walls, similar to high chimneys comprising multiple flue gas ducts. The height of pre-designed SUCs presently reaches up to 1000 m. Thus they are exposed chiefly to extreme wind-loads and thermal actions from the internal flow of warm air. As first design attempt, the structural analysis of solar chimneys generally is carried out by linear elastic models. For optimization, the typical shell-like wind stresses have to be constraint towards a more beam-like response behavior, approaching as far as possible linear stresses over the entire chimney circumference. This requires rather strong ring stiffeners, either as spoke-wheels in the designs of sbp (Schlaich Bergermann and Partners) or as external stiffeners in the designs of K&P (Krätzig and Partners). Both alternatives require considerable construction efforts leading to high investment costs. There exists an interesting simplification of this stiffening, namely applying to the SUC shell relatively soft external rings, and admitting large-widths cracking in the limit state of failure. This cracking constraints and equalizes the meridional stresses over the chimney’s cross-section, saving large amounts of reinforcement steel in the SUC. The design requires materially nonlinear analyses to verify the internal forces under crack-formations. The manuscript will derive this concept and demonstrate the crack analysis by example of a 750 m high solar chimney.
39
Borushchak, L. O., and B. B. Vynnychuk. "IMPROVEMENT OF THE CONSTRUCTION AND COMPUTER DEVICE INVESTIGATION FOR THE PROCESSING OF BLOWOUT-PREVENTION HARDWARE EQUIPMENT." Scientific Bulletin of Ivano-Frankivsk National Technical University of Oil and Gas, no. 1(46) (June 26, 2019): 16–24. http://dx.doi.org/10.31471/1993-9965-2019-1(46)-16-24.
Full textAbstract:
The research deals with the problem of blowout equipment test for tightness before implementation. The indicated equipment includes a stem, a system of pipelines with valves and a control system. The classic test procedure requires a mobile pumping installation that provides a pressure of 35 MPa.The cost of such tests is rather high. For testing without a pump unit, a design of a device for increased tightness has been developed, including a sealing unit of the mouth from the main column and a piston unit for creating high pressure in the test volume. Generation of a high pressure occurs by lifting the piston with a winch, mounted on the well. Disadvantages of the previously proposed design of the device are as follows. There is a considerable friction between the steel moving parts of the sealing unit. Mostly these are the pairs of a plug and a cup, and a chuck and a cone. Tightness is provided by rubber ring sleeves. Exceedence of axial load on cones causes destruction of sealing rings. The authors of the article improved the design of the sealing unit in the following way: a ball thrust bearing was seated between the ends of the pressure plug and the bottom cup and as a result the sliding friction was replaced with sliding friction. On the outer surfaces of the opening cones in contact with clamping blades, it is proposed to paste a tissue antifriction material of type Nafthlene or equivalent. The friction coefficient in such pairs is next lower order than in steel to steel pairs. The computer model of the device has been created in the Solid Works environment. The computer researches of the loading process of components of the sealing unit in the simulation program based on the finite element method were performed. As a result of the research, recommended values of the axial force, required to create a screw pair of a stem and a plug for sufficient radial axial deformation of elastic cuffs with the simultaneous non-admission of their destruction were identified. Also, the design dimensions of the pressure cups of the device were optimized, namely, the mutual axial placement of the end face, which presses on the cone, and the tapered belt, compressing the sealing ring. The determination of these parameters by an experiment is a long and expensive process.
40
Bogdevičius, Marijonas, Jurgis Jurevičius, and Bronislovas Spruogis. "ROTARY MOTION TRANSMISSION AND STABILIZATION DEVICES." TRANSPORT 19, no. 2 (April 30, 2004): 69–74. http://dx.doi.org/10.3846/16484142.2004.9637956.
Full textAbstract:
To connect rotors, to transmit and stabilize rotation motion a new class of rotary motion transmission and stabilization devices (RMTSD) was developed. They include the rings which deform axialy, radially and at an angle the radial segments, etc. with joined concentrated inertial, dissipative and elastic elements. RMTSD design schemes are copyrighted and covered by the patents of the USA, England and Germany. The classification of RMTSD development is performed according to the following characteristic features: dynamic characteristics, kind of elastically creeping elements, peculiarities of design elements, fastening, materials, etc. The classification presented gives the possibility to develop lots of constructions of new RMTSD of this type.
41
Sergeev, S. A., and M. N. Mikhaylova. "ANALYSIS OF EFFECTIVENESS OF THE MECHANICAL SHOCK ABSORBER PERFORMANCE." Oil and Gas Studies, no. 3 (June 30, 2015): 111–13. http://dx.doi.org/10.31660/0445-0108-2015-3-111-113.
Full textAbstract:
A design and the results of testing the mechanical shock absorber containing a body, in the bottom part of which there is a shaft forming together with a nut interacting with it via the spline joint a clearance is considered. Inside the bottom part of the body there are rows of damping rubber elements in the form of a ball which are separated by metal rings, and in the upper part of the body above the damping elements there is a piston fixedly connected with the shaft. The main advantages of the described design and the results of the pilot tests of samples proving the constructions operability are highlighted.
42
Hou, Lei, Dezhi Chen, Tongfei Li, Ming Zhao, and Huaibo Ren. "Design and Research on DC Electric Leakage Protection Circuit Breaker." Energies 15, no. 15 (August 2, 2022): 5605. http://dx.doi.org/10.3390/en15155605.
Full textAbstract:
In recent years, DC power supply and distribution technology plays an increasingly significant role in power supply and distribution systems with a low loss and large power supply radius. However, the corresponding DC distribution network protection electric devices cannot satisfy the needs of the existing DC power supply and distribution network. Based on this, in this article, an intelligent/energy-efficient DC leakage protection circuit breaker based on two-phase magnetic nanomaterials and detection and control technology is proposed. Firstly, the core of an intelligent/energy-efficient DCCB is composed of two-phase magnetic nanomaterials, and the mathematical modeling process, preparation and processing method of two-phase magnetic nanomaterials are given. Secondly, the DC leakage detection technology is studied by fluxgate technology, and the design process of magnetic rings, winding and detection circuit is given. Thirdly, the simulation and experiment results of the detection system and actuator are given by the simulation and experiment of an intelligent/energy-efficient DCCB to verify the correctness of the proposed scheme.
43
Wei, Liang, Yongcheng Li, Zhimei Cui, Baoshi Wang, Guanlang Huang, Zhiming Wang, and Jie Wei. "Research and Demonstration of Intelligent Multi-Physical Quantity Integration Sensor for Transmission Lines." Journal of Physics: Conference Series 2215, no. 1 (February 1, 2022): 012021. http://dx.doi.org/10.1088/1742-6596/2215/1/012021.
Full textAbstract:
Abstract The digital grid requires sensors to be widely deployed, safe, and reliable. At present, the single functional sensors suffered from redundant sensing system, repeated construction and low utilization rate. Therefore, this paper researched the multi-physical quantity integration sensor for a quad-bundle spacer on 500kV transmission lines. The sensor was composed of self-supplying rings and the monitoring host. Based on the non-contact current measurement technology, energy supply technology, intelligent sensing technology, low power consumption technology, reliability design technology, and other advanced technologies, this paper designed the hardware, software, and protective structure of the sensor, which can monitor the current and temperature of bubbles, channel side image and infrared image on transmission lines, ambient temperature, humidity, and air pressure. Finally, the multi-physical quantity integration sensors have been used on transmission lines in China Southern Power Grid, and the functions were verified. The sensors promote the automation, information, and digitization of monitoring transmission lines.
44
Macnar, Kazimierz, Andrzej Gonet, and Stanisław Stryczek. "Wybrane zagadnienia geotechniczne posadowienia urządzeń wiertniczych." Nafta-Gaz 77, no. 5 (May 2021): 313–22. http://dx.doi.org/10.18668/ng.2021.05.04.
Full textAbstract:
This article presents selected geotechnical issues occurring at the foundation of drilling rigs for geological works included in the Operation Plan of a company performing geological works, in the aspect of designing and construction of their foundations and a yard. In the construction of drilling equipment, at least two main zones can be distinguished, often requiring separate foundations for individual machines: the zone near the borehole, including crane components, mast and drill pipe drive, and the so-called machine hall zone, including drive units and elements of mud system. The machine foundation is designed to mount a particular type of machine on it in order to transfer to the ground the static and dynamic loads generated during the movement of the machine. In particular, the current legislation, technical literature and standards were reviewed, especially: API recommended practice 51R and 4G, Working platforms for tracked plant, Eurocode 7 PN-EN 1997-2:2009 Standard. The values of safe bearing capacity of some soils and the magnitude of pressures generated by static and dynamic loads of selected drilling equipment were presented, which can be useful for preliminary assessment of the location of drilling equipment in the field and selection of surface and type of foundations. Typical examples of foundation of drilling rigs in various geotechnical conditions on direct foundations with the use of prefabricated elements such as reinforced concrete road slabs, wooden slabs and composite slabs based on HDPE plastic or on indirect ones with the use of micropiles were described. The following essential elements of the process of geotechnical design of the foundation of drilling rigs and their execution were indicated. According to legal regulations, the form of presentation of geotechnical foundation conditions and the scope of necessary tests should depend on assigning the building structure to a proper geotechnical category, which for practical purposes is tabulated in this article. The design and construction of foundations for drilling rigs should ensure, among other things, that their intrinsic vibrations are sufficiently different from those induced by subassemblies of the rig, that the vibration amplitudes are smaller than permissible, and that the foundations of individual machines are adequately separated from each other and from the rest of the facilities (yard). Conclusions on the safe foundation of drilling rigs on the ground, including, among others, the strengthening of the ground, design of independent building structures such as foundations for drilling rigs and their execution and removal were presented.
45
Moreno-Martínez, Jatziri Y., Arturo Galván, Fernando Peña, and Franco Carpio. "Practical Model Proposed for the Structural Analysis of Segmental Tunnels." Applied Sciences 10, no. 23 (November 28, 2020): 8514. http://dx.doi.org/10.3390/app10238514.
Full textAbstract:
The construction of tunnels has become increasingly common in city infrastructure; tunnels are used to connect different places in a region (for transportation and/or drainage). In this study, the structural response of a typical segmental tunnel built in soft soil was studied using a simplified model which considers the coupling between segmental rings. From an engineering point of view, there is a need to use simple and reliable finite element models. Therefore, a 1D model based on the Finite Element Method (FEM) composed of beam elements to model the segments and elastic-linear springs and non-linear springs to model the mechanical behavior of the joints was performed. To validate the modeling strategy, the numerical results were compared to (lab-based) experimental results, under an Ultimate Limit State, obtained from the literature, and a comparison between numerical results considering a 3D numerical complex model which included the nonlinearity of concrete, reinforcing steel and the joints was performed. With this simplified model, we obtained a prediction of approximately 95% of the ultimate loading capacity compared to the results developed in the experimental and 3D models. This proposed model will help engineers in practice to create “rational” structural designs of segmental tunnel linings when a “low” interaction between rings is expected.
46
Mongwaketsi, Nametso, Noluthando Mayedwa, Nolubabalo Matinise, Kasinathan Kaviyarasu, Raymond Sparrow, and Malik Maaza. "Polymer matrices for porphyrin nanorods incorporation. Artificial light harvesting applications." Journal of Porphyrins and Phthalocyanines 22, no. 04 (April 2018): 303–17. http://dx.doi.org/10.1142/s1088424618500268.
Full textAbstract:
This contribution is focused on the supramolecular approach in exploration of aggregates formation by two different porphyrins wherein self-assembly plays an important role. Spectroscopic and microscopic studies usually provide information on investigations regarding the effects of various parameters on the fabrication of porphyrin aggregates by ionic self- assembly. Various properties of ionic self-assembled porphyrin nanorods have been investigated, including nonlinear optical (NLO) properties, and these studies were influenced by the fact that porphyrins have great thermal stability and extended [Formula: see text]conjugated macro cyclic rings which give them large nonlinear optical effects. The major reasons limiting porphyrin nanorods photonic applications include the difficulty of handling them in liquid solutions and their degradation with long exposure to light. This necessitates the use of appropriate solid matrices to host the nanorods. Inspired by the precise organization and orientation of the chromophores in natural systems, attention has been on the design of nanometer sized chromophoric assemblies, which may find applications in the field of molecular photonics. However, it is challenging to design multicomponent systems with controlled structural arrangement at the molecular level. A lack of precise arrangement may have a negative impact on the construction of an efficient artificial light harvesting system. This review is focused on exploring the possibility of incorporating nanorods into polymer matrices to overcome the limiting factors of applications of these materials in photonic devices.
47
Akhmedov, Ikromali, and Zulfiya Mirkhasilova. "Construction of vertical drainage wells using corrosion resistant materials." E3S Web of Conferences 264 (2021): 04016. http://dx.doi.org/10.1051/e3sconf/202126404016.
Full textAbstract:
Vertical drainage wells in terms of construction technology and design do not differ from wells for irrigation. They are not deeper in-depth than irrigation wells and are generally 40-70 m. The main task of vertical drainage wells is land reclamation. They, depending on natural and economic conditions, serve on 5-120 hectares of area. In many areas, vertical drainage wells serve a dual purpose; land reclamation and irrigation of agricultural crops. Water intake wells, including vertical drainage wells, are characterized by a decrease in their flow rates during operation. To ensure the stable operation of the irrigation and drainage system, where water intake wells are operated, repair and restoration work is carried out on them, aimed at increasing flow rates. For the construction of vertical drainage wells in the Sirdarya river basin, steel pipes and filters are mainly used, which corrode in an aggressive environment. In the water intake zone of the well and the metal corrosion process, the colmatation process also occurs. All of them are the main reasons for the decline in well production rates. The carried out repair and restoration measures are aimed at destroying the structure of corrosion and clogging products. In practice, mechanical, physical, biological, and chemical methods are used to clean the filters of water intake wells. They all have their own technology and equipment. However, all these works do not exclude the repeatability of the process. Repetitive workover will come to ineffective, the stage of good concertation is approaching. It is known that polymeric materials do not corrode. They work steadily in aggressive environments. To prevent the corrosion process, polymeric-seam pipes were used as a filter frame and a casing for the construction of vertical drainage wells. Two pilot wells were built on the territory of the Chiyili district of the Kyzylorda region of the Republic of Kazakhstan. The wells were drilled with a rotary drilling unit with backwash. Pure water (irrigation) was used as drilling fluid. To form a gravel pack in the annular zone of the casing, gravel-sand material from the Jailma quarry was used. The material was brought by rail and road transport. Pipe sections were prepared on the surface of 10 meters. Steel rings were put on the pipe from both ends of each section; their connection in the barrel was made by electric welding. The results showed that in the initial period of operation, a decline process was observed. In further exploitation, the well flow rate stabilized. As a result of construction using pipes and filters made of polymer material, the effect was achieved in terms of water volume more than 3 times and in terms of service life 4.2 times compared to a metal filter well.
48
Lu, Ping, Dajun Yuan, Weiping Luo, Dalong Jin, and Minggao Liu. "Centrifugal Model Test Study on the Mechanical Characteristics of Shield Tunnels Influenced by Different Types of Openings for Cross Passages." Applied Sciences 12, no. 13 (June 24, 2022): 6421. http://dx.doi.org/10.3390/app12136421.
Full textAbstract:
To investigate the mechanical characteristics of shield tunnels when openings are made for the construction of cross passages, a series of centrifugal model tests were conducted. The segmental features of the shield tunnel were simulated in the tests, and the influence of different types of openings, namely, rectangular opening, small circular opening, and big circular opening was compared. External earth pressures, structural deformations, dislocations, and structural stresses were monitored during the tests, while the influence of different buried depths was also investigated. The results show that (1) soil arching effect occurred in the overlying soil due to the deformation of the tunnel, and the earth pressure reduction coefficients can guide the tunnel structural design; (2) vertical deformations of the main tunnel and the dislocations between adjacent rings increased with the opening sizes significantly; (3) significant stress concentration occurred close to the openings, and the compressive stress at the inner surface may even exceed the limit strength of the concrete. In summary, the adverse responses of the tunnel increased with the increase of the buried depth and the opening size. Targeted measures should be taken, such as temporary support, longitudinal connections, and high-strength materials near the openings.
49
Romankiewicz, Tanja. "ROOM FOR IDEAS: TRACING NON-DOMESTIC ROUNDHOUSES." Antiquaries Journal 98 (September 2018): 17–42. http://dx.doi.org/10.1017/s0003581518000148.
Full textAbstract:
Iron Age studies in Britain operate in a world populated by roundhouses. Post-ring evidence is generally interpreted in domestic contexts. However, research on later prehistoric roundhouses in north-east Scotland has identified a small yet significant number of round structures in unusual locations, with unusual architectural details and a distinct lack of domestic material. Some of these relate to Chalcolithic and Early Bronze Age stone circles, for which Richard Bradley’s work in the wider region has highlighted progressive biographies of construction and reuse. This paper, rooted in architectural design theory, selects a particular case study – the multiple timber post-rings at Candle Stane (in Aberdeenshire) – to highlight the complexities in interpreting these fascinating and enigmatic buildings. The architectural approach develops alternative reconstructions that lead to new perspectives on later prehistoric architecture as event-based and concerned with process. These processes only gradually lead to an architectural end-product, which displays distinctly non-domestic connotations. The research not only highlights the usefulness of data derived from rescue work for academic study, but the advocated approach of reconstructing in alternatives also lends itself to developing innovative approaches in Higher Education to teach visual competence.
50
Sedenkova, Kseniya N., Olga V. Ryzhikova, Svetlana A. Stepanova, Alexei D. Averin, Sergei V. Kositov, Yuri K. Grishin, Igor P. Gloriozov, and Elena B. Averina. "Bis(oxiranes) Containing Cyclooctane Core: Synthesis and Reactivity towards NaN3." Molecules 27, no. 20 (October 14, 2022): 6889. http://dx.doi.org/10.3390/molecules27206889.
Full textAbstract:
Reactions of oxirane ring opening provide a powerful tool for regio- and stereoselective synthesis of polyfunctional and heterocyclic compounds, widely used in organic chemistry and drug design. Cyclooctane, alongside other medium-sized rings, is of interest as a novel molecular platform for the construction of target-oriented leads. Additionally, cyclooctane derivatives are well known to be prone to transannular reactions, which makes them a promising object in the search for novel approaches to polycyclic structures. In the present work, a series of cyclooctanediones was studied in Corey-Chaykovsky reactions, and novel spirocyclic bis(oxiranes) containing cyclooctane core, namely, 1,5-dioxadispiro[2.0.2.6]dodecane and 1,8-dioxadispiro[2.3.2.3]dodecane, were synthesized. Ring opening of the obtained bis(oxiranes) upon treatment with sodium azide was investigated, and it was found that the reaction path is determined by the reciprocal orientation of oxygen atoms in the oxirane moieties. Diastereomers of the bis(oxiranes) with cis-orientation underwent independent ring opening, supplying corresponding diazidodiols, while in the case of stereoisomers with trans-orientation, domino-like reactions occurred, including intramolecular nucleophilic attack and the formation of a novel three- or six-membered O-containing ring. Summarily, a straightforward approach to polyfunctional compounds containing cyclooctane or oxabicyclo[3.3.1]nonane cores, employing bis(oxiranes), was elaborated.