Journal articles on the topic 'Superstructure'
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1
Mackney, Michael D. A., and Carl T. F. Ross. "Superstructure Effectiveness in the Preliminary Assessment of the Hull Behavior." Marine Technology and SNAME News 36, no. 01 (January 1, 1999): 29–44. http://dx.doi.org/10.5957/mt1.1999.36.1.29.
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In a study of hull-superstructure interaction, a parametric investigation was undertaken, which was designed to examine a large number of hull-superstructure arrangements, broadly representative of warship configurations. The study was essentially numerical, based on the finite element method, but was supported by an experimental program used to validate aspects of the modeling. The majority of the numerical work was the analysis of three-dimensional simplified models having either a single superstructure on a standardized hull, or a double superstructure arrangement on an alternative standardized hull. Such models represented simplified structural configurations from which preliminary assessments of the hull-superstructure behaviour could be systematically addressed within an initial design sequence. Superstructure effectiveness is not universally defined or used, in the literature. Since stresses are idiosyncratic, effectiveness in this work is defined in terms of overall structural displacement, as the ratio of the maximum displacement of the plain hull to the maximum displacement with superstructures. A variety of cases was considered, including single and double superstructure arrangements of various sizes and in various positions on the hulL Design curves were formed for the different arrangements showing the variation in the effectiveness. Superstructure effectiveness varies with superstructure length, becoming greater as the superstructure becomes longer. There is a finite limit to the maximum effectiveness which is dependent on the relative cross sectional properties. The position of the superstructure also affects the effectiveness, with the greatest effectiveness occurring at the mid hull position. The change in effectiveness is less when the superstructure is small and changing position than when it is long. Two superstructures having comparable total length to a single superstructure are less effective than the single superstructure. Three superstructures are more effective than two, but still less than one. As the number of superstructures increases for a given total length, the effectiveness tends towards the single superstructure value. Superstructures, even of modest dimensions, considerably to the cross-sectional properties and should be considered as part of the hull girder when doing the preliminary design.
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Khalikov, A. R., Yu V. Bebikhov, E. A. Korznikova, and S. V. Dmitriev. "Planar superstructural defects in the alloys with L10 superstructure." Frontier materials & technologies, no. 3 (2022): 90–98. http://dx.doi.org/10.18323/2782-4039-2022-3-2-90-98.
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Planar superstructural defects have a great influence on the mechanical, functional properties of binary ordered alloys of the L10 superstructure based on the fcc lattice, but there is no complete analysis of their structure and energy in the literature. For the L10 superstructure alloys of the stoichiometric composition AB, the paper gives the expressions for calculating the sublimation energy and the energy of a planar superstructural defect in the model of hard coordination spheres and pair interatomic interactions. The crystal lattice tetragonality was not taken into account. The authors presented the ordered alloy structure as a union of four monoatomic simple cubic lattices, two of which are occupied by A atoms, and the other two by B atoms. This approach allows calculating the sublimation energy required for crystal evaporation. The first eight coordination spheres were taken into account in the work. The paper shows an algorithm for determining all possible geometrically different representations of the L10 superstructure with the same sublimation energy, gives an expression for finding the planes of occurrence of all possible conservative antiphase boundaries. The study identified that the conservative and nonconservative antiphase boundaries, as well as conservative and nonconservative boundaries of C-domains are observed in the binary ordered alloys of the L10 superstructure based on the fcc lattice. The algorithms described in this work make it possible to carry out a crystal-geometric analysis of planar defects in both binary and multicomponent ordered alloys with various superstructures.
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Костенко, М. Г., and А. А. Ремпель. "Распределение вакансий в гибридной сверхструктуре M-=SUB=-(5-11/18)-=/SUB=-X-=SUB=-(5-11/18)-=/SUB=- высокотемпературной упорядоченной фазы beta-TiO." Физика твердого тела 60, no. 3 (2018): 456. http://dx.doi.org/10.21883/ftt.2018.03.45544.254.
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AbstractA new structural model of the high-temperature ordered β-TiO phase of titanium monoxide with vacancies in metallic and nonmetallic sublattices has been proposed. The model suggests that the vacancies are simultaneously distributed over sites of two partially disordered superstructures: monoclinic M_5X_5(mon) (space group C 2/ m ( A 2/ m )) and cubic M_5X_5(cub) (space group Pm $$\overline 3 $$ 3 ¯ m ). The hybrid superstructure belongs to space group P 1 m 1 of the monoclinic system. The proposed notation M_(5–11/18)X_(5–11/18) of the hybrid superstructure takes into account an expansion of the vacancy sublattice due to the superposition of initial $${M_5}{X_{{5^ - }}}$$ M 5 X 5 − type superstructures. It is shown that the arrangements of the superstructure reflections in the diffraction spectra of the M_(5–11/18)X_(5–11/18) and M_5X_5(cub) superstructures are identical.
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Paßens, Michael, Rainer Waser, and Silvia Karthäuser. "Enhanced fullerene–Au(111) coupling in (2√3 × 2√3)R30° superstructures with intermolecular interactions." Beilstein Journal of Nanotechnology 6 (June 29, 2015): 1421–31. http://dx.doi.org/10.3762/bjnano.6.147.
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Disordered and uniform (2√3 × 2√3)R30° superstructures of fullerenes on the Au(111) surface have been studied using scanning tunneling microscopy and spectroscopy. It is shown that the deposition and growth process of a fullerene monolayer on the Au(111) surface determine the resulting superstructure. The supply of thermal energy is of importance for the activation of a Au vacancy forming process and thus, one criterion for the selection of the respective superstructure. However, here it is depicted that a vacancy–adatom pair can be formed even at room temperature. This latter process results in C60 molecules that appear slightly more bright in scanning tunnelling microscopy images and are identified in disordered (2√3 x 2√3)R30° superstructures based on a detailed structure analysis. In addition, these slightly more bright C60 molecules form uniform (2√3 x 2√3)R30° superstructures, which exhibit intermolecular interactions, likely mediated by Au adatoms. Thus, vacancy–adatom pairs forming at room temperature directly affect the resulting C60 superstructure. Differential conductivity spectra reveal a lifting of the degeneracy of the LUMO and LUMO+1 orbitals in the uniform (2√3 x 2√3)R30° superstructure and in addition, hybrid fullerene–Au(111) surface states suggest partly covalent interactions.
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Chen, Minglin, Bo Huang, Zhiying Yang, Qingyang Ren, and Bing Zhu. "The Influence of Lateral Restraining Stiffness on the Box-Girder Superstructure under Unbroken Solitary Waves." Journal of Marine Science and Engineering 10, no. 8 (July 26, 2022): 1019. http://dx.doi.org/10.3390/jmse10081019.
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At present, box-girder superstructures are commonly used in coastal bridges, and their hydrodynamic performance under extreme waves such as tsunamis has attracted a lot of attention. There is a lack of research focusing on the effect of lateral restraining stiffness on box-girder superstructures under the extreme wave condition. In this paper, a two-dimensional numerical model based on the RANS equation and SST k-ω turbulence model is established. Combined with the dynamic mesh updating technique, the effect of lateral restraining stiffness on the superstructure of a box-girder and the dynamic characteristics of the movable box-girder under the solitary waves were investigated. To ensure the mesh quality, the numerical computational domain is divided into several regions that correspond to specific types of body motion. The numerical model is verified by comparing it with other numerical simulation results and experimental results. The dynamic characteristics and the wave forces of the box-girder superstructure under the effect of lateral restraining stiffness under the unbroken solitary waves are discussed. The results show that the horizontal and vertical forces on the box-girder superstructure under the action of unbroken solitary waves can be reduced by reducing the lateral restraining stiffness. However, with the decrease in lateral restraining stiffness, the lateral displacement of the box-girder superstructure would increase. Therefore, the lateral restraining stiffness and lateral displacement limit of the box-girder superstructure should be fully considered in practical engineering, and the appropriate lateral restraining stiffness should be selected to reduce the wave forces on the box-girder superstructure under extreme wave action, so as to improve the safety of the coastal box-girder superstructure. It is of great importance to study the interaction between the box-girder superstructure and unbroken solitary waves, which will help to have a deeper understanding to improve the disaster resistance of bridges.
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Veselov, Vitaliy. "Application of Steel-Reinforced Concrete Structures in Bridge Constructions." Proceedings of Petersburg Transport University 20, no. 3 (September 21, 2023): 633–44. http://dx.doi.org/10.20295/1815-588x-2023-3-633-644.
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Purpose: To analyze the possible use of combined structures for bridge superstructures, to expand the range of steel-reinforced concrete structures, to explore innovative structural solutions for beams with low material consumption and increased reliability and durability. Methods: Analysis of the advantages of known combined structures, of materials used for their design, calculation of design options of bridge superstructures with the use of existing engineering techniques and involving calculation programs. Results: Traditional design solutions of bridge superstructures do not always have sufficient reliability and durability. A number of effective beam structures have been developed at the Department of “Building Structures, Buildings and Constructions” of the PGUPS, which can be used in bridge structures. New developments of beams with the use of steel-reinforced concrete and steel-fiber concrete are presented. A combined design of the bridge superstructure with the use of steel-reinforced concrete and steel-fiber concrete, protected by patents for inventions, is proposed. Static and constructive calculation of superstructure variants has been performed with the use of the SCAD computing complex, the stress-strain state of the structure has been analyzed, the reduction of material consumption, labor intensity and other advantages of the combined superstructure design in comparison with traditional solutions of superstructure costructions made of steel and reinforced concrete have been considered. Practical significance: The advantages of combined constructions for bridge structures have been identified, a decrease in the material intensity and labor intensity of the proposed design solutions has been established with an increase in the bending stiffness of the superstructure, its reliability and durability. The proposed structural solutions of beams can be used for bridges of large spans in conditions of heavy dynamic loads.
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Majlesi, Arsalan, Adnan Shahriar, Reza Nasouri, Hamid Khodadadi Koodiani, Arturo Montoya, Ao Du, and Adolfo Matamoros. "Digital Filter Design for Force Signals from Eulerian–Lagrangian Analyses of Wave Impact on Bridges." Journal of Marine Science and Engineering 10, no. 11 (November 14, 2022): 1751. http://dx.doi.org/10.3390/jmse10111751.
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Finite element (FE) models that simulate wave–superstructure interactions with the coupled Eulerian–Lagrangian (CEL) technique provide a viable and economical solution to estimate wave impact forces on bridge superstructures. One of the main drawbacks of CEL FE models is that they produce solutions distorted by numerical artifacts with very high frequencies that make it difficult to quantify the magnitude of hydrodynamic forces on superstructures. This paper investigated digital filter parameters for horizontal forces extracted from CEL FE models. The optimal filter configuration was evaluated by comparing unfiltered and filtered horizontal force signals with experimentally measured values from a reduced-scale superstructure specimen tested at the O.H. Hinsdale Wave Research Laboratory at Oregon State University. It was found that digital filters with cutoff frequencies below the fundamental frequency of the superstructure produced the best results and that optimizing Eulerian–Lagrangian surface interactions significantly improved the quality of the calculated force signals.
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Bin Yusof, Mustafa, and Mohammad Amirul Affiz Bin Afripin. "Effect of Beam Profile Size on Bus Superstructure Strength Having Rollover Crash." Applied Mechanics and Materials 372 (August 2013): 620–29. http://dx.doi.org/10.4028/www.scientific.net/amm.372.620.
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This paper deals with structural analysis of bus superstructure undergoes rollover event. Bus superstructure with varying beam profile size will undergo rollover simulations analysis. The purpose of this work is to analyze structural response of bus superstructure in terms of deformation, stress and strain under several loadings and constraining conditions. These rollover simulations were run according to United Nation Economic Commission of Europe Regulation 66 (UNECE R66). Validation procedure using simple box modeled undergoes rollover have been done to ensure the results are synchronized with real problem. An interaction with bus coach builder allows author acquired accurate bus superstructure dimensions before designing the mathematical model in finite element analysis software. Three full-scale bus superstructures mathematical model with difference cant-rail horizontal roof beam profile size was developed and the deformation of superstructure during and after rollover testing had been study. Analyses suggested that one of the contributing factors that lead to the failure of bus having rollover accident is cant-rail and roof structure profile size.
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Ge, S. P., and K. H. Kuo. "Ordered γ-brass structures coexisting with the decagonal quasicrystal in a Ga46Fe23Cu23Si8 alloy." Journal of Materials Research 14, no. 7 (July 1999): 2799–805. http://dx.doi.org/10.1557/jmr.1999.0374.
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In a moderately rapidly solidified Ga46Fe23Cu23Si8 alloy, a face-centered-cubic (fcc) superstructure (a = 1.78 nm) and a hexagonal superstructure (ahex = 2.18 nm and chex = 0.77 nm), based on the same body-centered-cubic (bcc) γ-brass structure (a = 0.89 nm), were found—by means of micro-area electron diffraction—to coexist with the decagonal quasicrystal. The fcc superstructure is probably similar to one of the F-centered-γ-brass structure and has a parallel orientation relationship with the bcc fundamental structure. The hexagonal superstructure has its (001) parallel to the (111) of the bcc γ-brass structure and its chex = abcc[111]/2, and their lattice correspondence relationship has been derived. Electron diffraction evidence is presented to show that these two superstructures are possibly crystalline approximants of the decagonal quasicrystal.
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Deng, Jie, and Fulin Su. "Ship target recognition based on superstructure matching." E3S Web of Conferences 522 (2024): 01038. http://dx.doi.org/10.1051/e3sconf/202452201038.
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The Automatic Target Recognition(ATR) of ship targets based on Inverse Synthetic Aperture Radar(ISAR) images plays a significant role in naval warfare.To address the issue that existing superstructure-based recognition methods do not fully use superstructure shape information,we propose a novel automatic ship recognition method based on superstructure matching using the Dynamic Time Warping (DTW) algorithm.Firstly,the superstructures of each class are extracted from ISAR images after preprocessing and preliminary calibration,then the DTW algorithm is used to create the superstructure templates, and eventually the target's class is determined by the DTW distance from the templates.The proposed method is robust to ship deformation from changing aspect angles and requires few training samples per class.The experimental results of applying the technique on real ISAR data demonstrate the effectiveness of the proposed method.
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Rurua, Nugzar, Boris Maisuradze, and Ioseb Utmelidze. "DETERMINATION OF THE RESPONSE SPECTRA OF THE SUPERSTRUCTURE OF LENGTH L=3X63.0 M." AGG+ 12, no. 1 (June 1, 2024): 2–14. http://dx.doi.org/10.61892/agg202401r.
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<p>During a seismic impact, the main emphasis is placed on the damage to bridge piers, which were isolated from the horizontal earthquake detector. Accordingly, when calculating the bridges, the reaction spectra obtained from the horizontal earthquake detector are used both for the piers and for the superstructure. The issue of seismic resistance of bridges is very important, especially for superstructures with long spans. It is necessary to construct dynamic curves of seismic resistance for superstructures of a specific system. The article deals with composite steel and concrete continuous span superstructure with a scheme L=3x63.0 m, on which we performed seven real earthquake records for all three categories of soil using the direct dynamic method and built the reference response spectra. Based on the obtained response spectrum and the methodology provided by different normative documents, the calculation of the selected superstructure was carried out, and the force values were determined. <strong>Discussion:</strong> On the basis of the results obtained with the reference response spectra and the curves given in the normative documentation, graphs were drawn, and composite steel and concrete continuous span superstructure with a scheme L=3x63.0 m of the vertical response spectra was determined.</p>
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Nabizadeh, Azam, Habib Tabatabai, and Mohammad Tabatabai. "Survival Analysis of Bridge Superstructures in Wisconsin." Applied Sciences 8, no. 11 (October 28, 2018): 2079. http://dx.doi.org/10.3390/app8112079.
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Although survival analyses have long been used in biomedical research, their application to engineering in general, and bridge engineering in particular, is a more recent phenomenon. In this research, survival (reliability) of bridge superstructures in Wisconsin was investigated using the Hypertabastic accelerated failure time model. The 2012 National Bridge Inventory (NBI) data for the State of Wisconsin were used for the analyses. A recorded NBI superstructure condition rating of 5 was chosen as the end of service life. The type of bridge superstructure, bridge age, maximum span length (MSL) and average daily traffic (ADT) were considered as possible risk factors in the survival of bridge superstructures. Results show that ADT and MSL can substantially affect the survival of bridge superstructures at various ages. The reliability of Wisconsin superstructures at the ages of 50 and 75 years is on the order of 63% and 18%, respectively, when the ADT and MSL values are at Wisconsin’s mean values.
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Wu, Chong Fu, and Shu Hong Liu. "Interaction Analysis of the Superstructure and Raft Foundation for Tall Building with Podium." Applied Mechanics and Materials 71-78 (July 2011): 1720–23. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.1720.
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Based on the three-dimensional computation model, the actual project ,a high-rise building with podiums on the jointless raft foundation, is made nonlinear numerical analysis, which aims at studying the characters of superstructure-foudation-soil’s interaction, and analyzing the stress features in raft foundations under the former interaction , the distribution of stresses on foundation plate，and the range of stress dispersion about subgrade reaction. Through the factors, which can affect superstructure-foudation interaction, are analyzed , such as superstructure’s stiffness, foundation’s stiffness and soil’s stiffness. Then, the distribution rule of stress and deformation about superstructure-foudation interaction. Which can provide some calculation basis for this kind of foundation design.
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Greenberg, B. A., N. A. Kruglikov, L. A. Rodionova, A. Yu Volkov, L. G. Grokhovskaya, G. M. Gushchin, and I. N. Sakhanskaya. "Optimised Mechanical Properties of Ordered Noble Metal Alloys." Platinum Metals Review 47, no. 2 (April 1, 2003): 46–58. http://dx.doi.org/10.1595/003214003x4724658.
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The deformation behaviour of alloys that are ordered to form an L10 or L12 superstructure after heavy plastic deformation has been studied. Alloys with the LI0 superstructure, such as NiPt, FePd, CoPt and CuAu, possess an optimum combination of high strength and plasticity after thermomechanical treatment. However, such properties were not obtained in Pd3Fe, Pt3Co or Cu3Au which have the L12 superstructure. The structure of FePd was examined by transmission electron microscopy upon annealing after heavy drawing and a set of typical superstructural states was found. The conditions needed to impart high strength and plastic properties to some ordered alloys based on noble metals are discussed.
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Ng, Morgan. "The Renaissance Superstructure." Journal of the Society of Architectural Historians 81, no. 3 (September 1, 2022): 320–41. http://dx.doi.org/10.1525/jsah.2022.81.3.320.
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Abstract The Renaissance Superstructure charts the sixteenth-century reinvention of what Morgan Ng calls the superstructure: a typology of elevated defensive corridors that emerged during the Middle Ages and once traversed many European cities. Not unlike private helicopters today, such pathways afforded rulers secure and privileged mobility, enabling them to travel between their urban and extramural strongholds while remaining high above the chaos of the street. Against all odds, superstructures continued to thrive well into the early modern period, despite their military vulnerability in the age of artillery warfare. By morphing from utilitarian defenses into monumental systems of circulation, they served the rising bureaucratic, ritual, and symbolic demands of absolutist courts. The unlikely survival of an obsolescent architecture opens a window onto the complex dynamics of technical evolution and cultural change.
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Jun, Jae-Hyung, Suk-Chan Lee, Do-Sam Kim, and Kwang-Ho Lee. "Characteristics of Wave Pressures According to the Installation Location of the Caisson Superstructure under Regular Waves." Journal of Korean Society of Coastal and Ocean Engineers 34, no. 3 (June 30, 2022): 82–92. http://dx.doi.org/10.9765/kscoe.2022.34.3.82.
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In recent years, coastal and port structures have attempted to prevent wave-overtopping or provide waterfront areas by installing superstructures on the structural crowns. In general, in the design stage, the Goda formula acting on the front the structure is applied to calculate the wave pressure acting on the superstructure in consideration of the wave-runup of the design wave. However, the wave pressure exceeding the Goda wave pressure could generate depending on the installation location of the superstructure where the wave-overtopping occurs. This study analyzed the applicability of the Goda formula to the wave pressure calculation for the superstructure of the vertical structures through hydraulic model experiments and numerical simulations. Furthermore, this study investigated the magnitude of the wave pressure acting on the superstructure based on detailed numerical results. As a result, the wave pressure acting on the superstructure was up to 120% higher than the maximum wave pressure on the still water surface. In addition, the wave pressure increases exponentially with the Froude number computed by the overtopping water depth at the crown of the structure, and we proposed an empirical formula for predicting the wave pressure based on the Froude number.
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SHEN, JUNJIE, QIAN SUN, TIEJUN ZHU, and XINBING ZHAO. "SELF-ASSEMBLY OF BISMUTH SELENIDE TWO-DIMENSIONAL SUPERSTRUCTURE FROM HEXAGONAL NANOSHEETS." Functional Materials Letters 04, no. 03 (September 2011): 245–48. http://dx.doi.org/10.1142/s1793604711001956.
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A kind of novel superstructure array composed of hexagonal Bi2Se3 nanosheets were fabricated via a facile hydrothermal method. The structure was characterized by X-ray diffraction and field emission scanning electron micrioscopy. It is suggested that the two dimensional superstructure was self-assembled by sheet-like Bi2Se3 building blocks on naturally-formed Bi2SeO2 precusor template. The present result indicates one promising way in design and growth of self-assembled superstructures by controllable crystal growth from deoxided substrates with good lattice match.
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TANYILDIZI, Muhammed, and Muhammet ÇINAR. "The Effect of The Bearing Capacity of Sub-Grade Soil on The Thickness and Cost of The Superstructure of Chip Seals." Bitlis Eren Üniversitesi Fen Bilimleri Dergisi 12, no. 2 (May 23, 2023): 376–86. http://dx.doi.org/10.17798/bitlisfen.1213673.
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applied for preventative treatment of an existing road or to overlay low-trafficked roads. The thickness of the superstructure of a chip seal pavement is directly related to the bearing capacity of sub-grade soil. The bearing capacity of soil is represented by Resilient Modulus (MR) for the design of the thickness of layers. This study has focused on the effect of the bearing capacity of sub-grade soil on the thickness and cost of superstructures of chip seals. In addition, linear regression analysis was performed to investigate the relationship between the bearing capacity of the subgrade soil and the thickness of the superstructure. Two-dimensional numerical modeling was performed with the layer thicknesses found according to the resilient modulus. It was indicated that there was a strong correlation between the bearing capacity of sub-grade soil and the thickness of superstructures of chip seals with high R-square values. An increase in the bearing capacity of the subgrade resulted in a decrease in the thickness of the superstructures of the chip seal. So, it has importance in the aspect of economical to select the most proper soil that will be used in the superstructure of chip seals by taking care of the environment and conditions. In addition, Plaxis 2D modeling shows that a double-chip seal has less deformation and better bearing capacity than a single-chip seal.
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Marochka, V. V., and O. P. Verovka. "SPECIAL ASPECTS OF WORKING METAL TRUSSES FROM THE WIND LOAD." Science and Transport Progress, no. 17 (August 25, 2007): 204–8. http://dx.doi.org/10.15802/stp2007/17633.
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There is a problem of simplified of computational models, which are used at calculation and designing of metal superstructures as a frame. Sometime it leads to the considerable errors in calculations. In this work researches of dimensioned behavior of a superstructure by a finite element method was implemented. In the capacity of calculated construction the standard superstructure (a type project №690/2) has been used. Ground obtained results the model for calculation of supplemental forces in chords was designed, which simulate a behavior of constructional.
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Tamura, Shuji, Amane Kuriki, and Kohji Tokimatsu. "Ultimate Response of Superstructure Supported by Spread Foundation During Strong Earthquakes." Journal of Disaster Research 7, no. 6 (December 1, 2012): 718–25. http://dx.doi.org/10.20965/jdr.2012.p0718.
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Dynamic centrifuge tests were performed on soilstructure models to investigate the mechanism of the ultimate superstructure response during strong earthquakes. Two structure models, one each for a highrise building and a low-rise building, differed in height but had almost identical mass and natural frequency. The following conclusions were drawn: 1) Superstructure acceleration amplitudes tended to reach the limit, although ground surface acceleration amplitudes increased with increasing input motion for both structure models. 2)Maximumacceleration of the high-rise building’s superstructure was markedly less than that of the low-rise building but the ultimate overturning moment acting on the footing base in both cases was almost identical during strong earthquakes. Overturning moment depends not only on superstructure inertia but also on the height of the superstructure’s center of gravity. Maximum superstructure acceleration for the high-rise building model therefore became small. 3) The overturning moment limitation when rotation angles were large was caused by local soil failure under the footing edge because the overturning moment was less than ultimate value (=PB/2), P is the weight of the structure and B is the footing’s width, and the contact pressure of the footing edge reached its ultimate.
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Leung, Y. F., A. Klar, K. Soga, and N. A. Hoult. "Superstructure–foundation interaction in multi-objective pile group optimization considering settlement response." Canadian Geotechnical Journal 54, no. 10 (October 2017): 1408–20. http://dx.doi.org/10.1139/cgj-2016-0498.
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The full potential of pile optimization has not been realized as the interactions between superstructures and foundations, and the relationships between material usage and foundation performance are rarely investigated. This paper introduces an analysis and optimization approach for pile group and piled raft foundations, which allows coupling of superstructure stiffness with the foundation model, through a condensed matrix representing the flexural characteristics of the superstructure. This coupled approach is implemented within a multi-objective optimization algorithm, capable of providing a series of optimized pile configurations at various amounts of material. The approach is illustrated through two case studies. The first case involves evaluation of the coupled superstructure–foundation analyses against field measurements of a piled raft–supported building in London, UK. The potential benefits of pile optimization are also demonstrated through re-analyses of the foundation by the proposed optimization approach. In the second case, the effects of a soft storey on the superstructure–foundation interactions are investigated. These cases demonstrate the importance of properly considering the superstructure effects, especially when the building consists of stiff components such as concrete shear walls. The proposed approach also allows engineers to make informed decisions on the foundation design, depending on the specific project finances and performance requirements.
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Starostenkov, Mikhail, Alexandra Chaplygina, and Veronika Romanenko. "Details of the Formation of Superstructures in the Process of Ordering in Cu-Pt Alloys." Key Engineering Materials 592-593 (November 2013): 321–24. http://dx.doi.org/10.4028/www.scientific.net/kem.592-593.321.
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Alloys of Cu-Pt [1] are of interest for research, since the phase transitions "order - disorder" at different concentrations of components form several types of superstructures. In the alloy Cu3Pt the ordering L12 superstructure formed on the basis of fcc lattice. In the ordering of the fcc lattice of the disordered solid solution the equiatomic composition transformed into the L11 superstructure with an rhombohedral crystal lattice (a state with an L11, whose angles α, β, and γ are other than π/2). A CuPt3 in an ordered state has an L13 superstructure (a state with an L13, whose angles α, β, and γ are other than π/2). A possible existence of an ordered phase containing 20 at.% Pt was reported in the literature [2], which corresponds to the composition of Cu4Pt (type of superstructure was not defined). In other sources, an occurrence of an ordered compound, Cu7Pt, was predicted, containing 12.5 at.% Pt [3]. Computer experiments performed on the Monte Carlo method, showed that the alloys of the Cu - Pt different composition components undergo phase transformations "disorder - order" from the FCC to the structures of different symmetry [4,11]. This paper presents the results of a study of the structural transformations in the alloys Cu3Pt, CuPt, CuPt3 (superstructure L12, L11, L13), containing shear antiphase boundaries (APB) in the planes {111}.
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Korbova, A. "Development of lightweight polymeric-composite superstructure for a fast boat." Transactions of the Krylov State Research Centre S-I, no. 2 (December 28, 2020): 242–49. http://dx.doi.org/10.24937/2542-2324-2020-2-s-i-242-249.
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This paper discusses the design of lightweight polymeric-composite superstructure for a fast boat (displacement up to 1 t) with solar panels powering its propulsion motor. The superstructure is made up by composite beams with sufficient dynamic stiffness and strength to withstand operational loads. External load was defined as spectral, inertial, transmitted as accelerations or displacements from hull to the superstructure via bearing joints. The material was GFRP with foam filler. The simulation is performed as per finite-element method in linear spatial beam formulation, solving the problems of natural vibrations and maximum dangerous response to spectral kinematic effect as a superposition of modes weighed by spectral coefficients. The study presents calculation for the initial superstructure design and its variations, to analyse sensitivity of dynamic and spectral responses to design changes. The study implements a new technique of generating a model of composite binary profile on single mesh. The results of this analysis, further verified on a more detailed idealization and supplemented by a calculation of inertial disturbances due to pitching and rolling, will yield the methodology for more computer-efficient design of lightweight superstructures for small boats made of polymeric composite materials.
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WANG, QIANG, HAN RUSHAN, D. L. YIN, and Z. Z. GAN. "A STUDY OF THE STABILITIES AND SUPERCONDUCTIVITIES OF THE SUPERSTRUCTURE IN YBa2Cu3O6+x SYSTEM (0 < x < 1)." Modern Physics Letters B 06, no. 07 (March 20, 1992): 411–24. http://dx.doi.org/10.1142/s0217984992000508.
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We calculated the Madelung potentials of a set of possible oxygen ordering superstructures of YBa 2 Cu 3 O 6+x system by using the standard Ewald method. According to the Madelung potential criteria on cations and anions, it is easy to present the possible stable superstructures. Furthermore, the density of carriers (hole or electron) for each superstructure was obtained and the superconductivities discussed.
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Jiao, Xiaojuan, Xiaojie Liu, Beibei Wang, Gang Wang, Xiujuan Wang, and Hui Wang. "A controllable strategy for the self-assembly of WM nanocrystals/nitrogen-doped porous carbon superstructures (M = O, C, P, S, and Se) for sodium and potassium storage." Journal of Materials Chemistry A 8, no. 4 (2020): 2047–65. http://dx.doi.org/10.1039/c9ta11312f.
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A series of WM (M = O, C, P, S, and Se) nanocrystals/N-doped porous carbon superstructures with superporous structures were generated and the resulting WSe2/N–PC superstructure was used as anode for both sodium and potassium storage.
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Heboyan, Artak, Roberto Lo Giudice, Les Kalman, Muhammad Sohail Zafar, and João Paulo Mendes Tribst. "Stress Distribution Pattern in Zygomatic Implants Supporting Different Superstructure Materials." Materials 15, no. 14 (July 16, 2022): 4953. http://dx.doi.org/10.3390/ma15144953.
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The aim of this study was to assess and compare the stress–strain pattern of zygomatic dental implants supporting different superstructures using 3D finite element analysis (FEA). A model of a tridimensional edentulous maxilla with four dental implants was designed using the computer-aided design (CAD) software. Two standard and two zygomatic implants were positioned to support the U-shaped bar superstructure. In the computer-aided engineering (CAE) software, different materials have been simulated for the superstructure: cobalt–chrome (CoCr) alloy, titanium alloy (Ti), zirconia (Zr), carbon-fiber polymers (CF) and polyetheretherketone (PEEK). An axial load of 500 N was applied in the posterior regions near the zygomatic implants. Considering the mechanical response of the bone tissue, all superstructure materials resulted in homogeneous strain and thus could reconstruct the edentulous maxilla. However, with the aim to reduce the stress in the zygomatic implants and prosthetic screws, stiffer materials, such Zr, CoCr and Ti, appeared to be a preferable option.
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Niu, Gefei, Jianchen Lu, Xingyue Wang, Zilin Ruan, Hui Zhang, Lei Gao, Jinming Cai, and Xiao Lin. "Se-concentration dependent superstructure transformations of CuSe monolayer on Cu(111) substrate." 2D Materials 9, no. 1 (November 24, 2021): 015017. http://dx.doi.org/10.1088/2053-1583/ac3888.
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Abstract As one of the most distinctive members of the monolayer transition metal monochalcogenides (TMM) family, the CuSe monolayer with a honeycomb structure has drawn much attention in the past few years. Depending on the Se concentration, the CuSe monolayer has two distinct superstructures on a Cu(111) substrate, a one dimensional (1D) moiré pattern, and two dimensional (2D) periodic nanopores. Here, we devise a strategy for simultaneous fabrication of the two superstructures of the CuSe monolayer on a Cu(111) substrate via artificially creating a density gradient of the Se concentration by an off-centered deposition method. At the boundary of the two superstructures, an intermediate state of the CuSe monolayer with a 2D hexagonal moiré pattern connected by six twisted petal-like stripes is observed. High-resolution scanning tunneling microscopy characterizations of three distinct CuSe monolayer superstructures demonstrate that the Se density can effectively modulate the stress in the CuSe monolayer formed by the lattice mismatch, driving the superstructure transformation from 1D moiré pattern through 2D intermediate states to 2D periodic nanopores. In addition, scanning tunneling spectroscopy measurements show that the intermediate state features a semiconducting behavior with a band gap of ∼2.0 eV. Our findings open up a new route for superstructure transformation control of 2D materials.
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Pradhan, Basudev, Sonali Das, Jinxin Li, Farzana Chowdhury, Jayesh Cherusseri, Deepak Pandey, Durjoy Dev, et al. "Ultrasensitive and ultrathin phototransistors and photonic synapses using perovskite quantum dots grown from graphene lattice." Science Advances 6, no. 7 (February 2020): eaay5225. http://dx.doi.org/10.1126/sciadv.aay5225.
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Organic-inorganic halide perovskite quantum dots (PQDs) constitute an attractive class of materials for many optoelectronic applications. However, their charge transport properties are inferior to materials like graphene. On the other hand, the charge generation efficiency of graphene is too low to be used in many optoelectronic applications. Here, we demonstrate the development of ultrathin phototransistors and photonic synapses using a graphene-PQD (G-PQD) superstructure prepared by growing PQDs directly from a graphene lattice. We show that the G-PQDs superstructure synchronizes efficient charge generation and transport on a single platform. G-PQD phototransistors exhibit excellent responsivity of 1.4 × 108 AW–1 and specific detectivity of 4.72 × 1015 Jones at 430 nm. Moreover, the light-assisted memory effect of these superstructures enables photonic synaptic behavior, where neuromorphic computing is demonstrated by facial recognition with the assistance of machine learning. We anticipate that the G-PQD superstructures will bolster new directions in the development of highly efficient optoelectronic devices.
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Bagautdinov, Bagautdin, Andreas Jobst, Jens Ludecke, and Sander van Smaalen. "Structural basis for the phase transitions of Cs2HgCl4." Acta Crystallographica Section B Structural Science 57, no. 3 (May 25, 2001): 231–36. http://dx.doi.org/10.1107/s0108768100020322.
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The a 0 × b 0 × 2c 0 twofold superstructure of dicaesium mercury tetrachloride, Cs2HgCl4, at T = 120 K has been determined by single-crystal X-ray diffraction using synchrotron radiation. Lattice parameters were found as a = 9.7105 (2), b = 7.4691 (1), c = 26.8992 (4) Å, and β = 90.368 (1)° with the supercell space group P21/c. Refinements on 1828 observed unique reflections converged to R = 0.053 (wR = 0.057) using anisotropic temperature factors for all atoms. This phase is the stable phase of Cs2HgCl4 below 163 K. A quantitative comparison is made of the distortions of the 2c 0 superstructure with the undistorted phase that is stable at room temperature, and with the 3c 0 and 5a 0 superstructures that are stable at temperatures between 163 K and room temperature. The principal difference between the 2c 0 superstructure and all other phases of Cs2HgCl4 is that the Cs cations are displaced away from the centers of their coordination polyhedra in the 2c 0 superstructure. The structural basis for the driving force of the series of phase transitions in this compound is found in the variations of the environments of Cs atoms and in the variations of the distortions of the HgCl4 tetrahedra.
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Håkonsen, Verner, Gurvinder Singh, Jianying He, and Zhiliang Zhang. "Focused ion beam milling of self-assembled magnetic superstructures: an approach to fabricate nanoporous materials with tunable porosity." Materials Horizons 5, no. 6 (2018): 1211–18. http://dx.doi.org/10.1039/c8mh01112e.
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Focused ion beam milling of self-assembled magnetic superstructures is demonstrated as a novel approach to fabricate porous materials with tunable porosity. During exposure to the ion beam, nanoparticles in the superstructure are subjected to combined milling and melting, thus merging together into a porous network.
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Mei, Kaili, Kejia Zhang, Jungu Xu, and Zhengyang Zhou. "The Application of 3D-ED to Distinguish the Superstructure of Sr1.2Ca0.8Nb2O7 Ignored in SC-XRD." Crystals 13, no. 6 (June 8, 2023): 924. http://dx.doi.org/10.3390/cryst13060924.
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Compared to X-rays, electrons have stronger interactions with matter. In electron diffraction, the low-order structure factors are sensitive to subtle changes in the arrangement of valence electrons around atoms when the scattering vector is smaller than the critical scattering vector. Therefore, electron diffraction is more advantageous for studying the distribution of atoms in the structure with atomic numbers smaller than that of sulfur. In this work, the crystal structure of Sr1.2Ca0.8Nb2O7 (SCNO-0.8) was analyzed using single-crystal X-ray diffraction (SC-XRD) and three-dimensional electron diffraction (3D-ED) techniques, respectively. Interestingly, the superstructure could only be identified by the 3D-ED technique, while no signal corresponding to the superstructure was detected from the SC-XRD data. The superstructure in SCNO-0.8 was disclosed to be caused by different tilting of NbO6 octahedra and the displacements of Sr/Ca atoms in the different atomic layers perpendicular to the a-axis. Therefore, the application of 3D-ED provides an effective method for studying superstructures caused by ordered arrangements of light atoms.
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Mone, Bhargav, Prof P. S. Mote, and Prof Dr Navnath V. Khadake. "Comparative Study of Wide Deck Box Girder Bridge Superstructures." International Journal for Research in Applied Science and Engineering Technology 10, no. 5 (May 31, 2022): 3376–85. http://dx.doi.org/10.22214/ijraset.2022.43128.
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Abstract: Box Girder superstructures are most popular type amongst all other type bridge superstructures and are extensively used. Nowadays to provide better riding quality and in order to reduce number of substructures and foundations for more clear space underneath, long span continuous or integral type bridge superstructures are preferred. For longer span bridges to reduce dead load and to utilize material to its capacity cellular sections are the most efficient sections in this regard. Box girder is one of the cellular sections. In metropolitan cities one of the restrictions is the availability of land to widen the existing roads. Present trend is to use wide deck bridge superstructure to utilize surface level and elevated level space more efficiently. Bridge aesthetics are also important as bridges are located in metro cities, tourist’s places. In wide deck bridges, ribbed cantilever slab or cantilever with supporting struts are used to impart transverse stiffness while further reducing dead load of the superstructure deck. Three different types of box girder superstructures are studied to inspect their behaviour in longitudinal and in transverse direction. Analysis of three different types of box girder superstructures has been carried out using software CSI SAP2000 and analysis results are presented and compared. In this parametric study various parameters of mechanical behaviour such as deflection, shear lag, effects, bending stresses in transverse direction are compared. Keywords: Box girder, Cellular sections, mechanical behaviour, shear lag, Bridge aesthetics
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Salamekh, A., M. Alsaid, and V. A. Petrovsky. "EXPERIMENTAL SETUP FOR STUDYING DURABILITY OF THE SHIP SUPERSTRUCTURES MATERIAL." Vestnik Gosudarstvennogo universiteta morskogo i rechnogo flota imeni admirala S. O. Makarova 14, no. 2 (June 28, 2022): 264–71. http://dx.doi.org/10.21821/2309-5180-2022-14-2-264-271.
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The description of an experimental setup for studying the durability of polymer composite materials samples which are used for the sea carrier ships superstructures manufacture is presented in the paper. The structural composition of the installation and methods of applying loads to the test sample are presented in detail. The installation includes a rocking table which simulates the rocking of the ship on which the test sample is fixed with bolted, riveted or adhesive connection methods. In this paper, an analysis of the loads affecting the walls of the superstructure is carried out. In particular, the area of the lower part connected to the main hull of the vessel during the operation of the vessel in marine conditions is analyzed. Acting loads on the test sample simulate the loads acting on the superstructures of sea vessels, in particular, on the junction of the superstructure with the main hull. During carrying out tests on this installation, it is possible to change the values of loads in accordance with the actual loading conditions of ship superstructures. The setup has a universal character and makes it possible to study the durability of samples made of polymer composite materials depending on their structural components, the number and arrangement of layers under certain loading conditions taking into account wind and wave loads as well as compressive loads that arise from the own weight of the superstructure. The calculation results of the stresses arising in the test sample under the action of the loads listed above are presented. The conclusion made proves the relevance and advantages of using the proposed installation for determining the durability of polymer composite materials and the tendency to improve it during further research.
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Jia, Bao Rui, Ming Li Qin, Ai Min Chu, Ye Liu, Qi Ping Kang, and Xuan Hui Qu. "Hydrothermal Preparation of Flower-Like CuS Superstructure and its Optical Property." Applied Mechanics and Materials 275-277 (January 2013): 2014–17. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.2014.
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The CuS flower-like superstructures were selectively and facilely synthesized by a hydrothermal method at 120 °C. The EDS, SEM, HRTEM and FFT results show that the CuS superstore has a well-defined uniform 3-dimensional flower-like morphology. These superstructures have sizes of about 500 nm and are built from several intersectional nanoplates, which have a mean length of about 500 nm and an average thickness of about 50 nm. Optical absorption spectrum of the CuS superstructure shows it has good absorption in the near-IR region and the band gap is 2.08 eV.
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Friedl, Caroline, Christian Scheidl, Susanna Wernhart, and Dirk Proske. "Laboratory experiments to analyse the influence of bridge profiles on debris-flow impact forces." E3S Web of Conferences 415 (2023): 02006. http://dx.doi.org/10.1051/e3sconf/202341502006.
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Debris-flow impact plays a significant role in the failure of bridges in mountainous areas posing a risk to human life and leading to high reconstruction costs. The aim of this study is to measure and quantify the frontal impact forces of debris flows on bridge superstructures based on laboratory experiments with a special regard to the comparison of two different bridge profiles and the presence / absence of a bridge pier. To this end, we conducted 20 experiments, measuring the frontal impact forces on the bridge superstructure with two 3-axis force sensors at the abutments of the miniature bridge. We found that the type of the superstructure does have an influence on the magnitude of the frontal impact forces.
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Yang, Hua, Jing Ru Zhang, Wentao Cao, Jin Zhen, and Ji Hong Wu. "Screw-Dislocation-Driven Hierarchical Superstructures of Ag-Ag2O-AgO Nanoparticles." Crystals 10, no. 12 (November 27, 2020): 1084. http://dx.doi.org/10.3390/cryst10121084.
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Constructing multi-dimensional hierarchical superstructures has been, for a longtime, regarded as a promising strategy for modifying the physiochemical properties of nanomaterials. Guided by this rule, this work reports the synthesis of hierarchical superstructures of Ag-Ag2O-AgO nanoparticles (HSANs) using a convenient and surfactant-less photochemical method under 254 nm UV-irradiation. The formation of the HSANs superstructures is dominated by screw-dislocation-driven growth mechanism at low supersaturation condition. The structural evolution of the HSANs superstructures has been systematically investigated. The average size of the HSANs superstructures increased with prolonged 254 nm UV-irradiation. The step density on the superstructure surfaces also increased along with the 254 nm UV-irradiation time.
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Jover, Vivien, and Szabolcs Fischer. "Statistical Analysis of Track Geometry Parameters on Tramway Line No. 1 in Budapest." Baltic Journal of Road and Bridge Engineering 17, no. 2 (June 27, 2022): 75–106. http://dx.doi.org/10.7250/bjrbe.2022-17.561.
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The article examines the superstructures of the tramway tracks of tramway line No. 1 in Budapest (the capital of Hungary). Since the first appearance of tramways, several technological advancements have been made to serve passenger needs as efficiently as possible. Several types of tramway track superstructure systems can be differentiated, which are implemented differently in each project. Furthermore, these superstructure types have different degradation times (both geometrical and structural), which depend on several factors. Nowadays, visual inspections are no longer considered sufficient in monitoring the tracks’ condition and deterioration, thus it is necessary to consider examinations carried out using the sensors mounted on the vehicles. Adopting appropriate methods, the measured data can be modeled and the life cycle of superstructures and structural elements can be determined as a result of sufficiently long-term studies (i.e., life cycle costs, the whole lifetime, etc.). First, the authors present a review of the relevant international literature, after that they conduct analysis of track geometry parameters of the superstructures related to five sections on the investigated tramway line based on the results of the measurements performed for three consecutive years between 2019 and 2021. The analyses consist primarily in statistical examination of the measured and calculated parameters.
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KUO, C. C., C. H. LIN, WOEI WU PAI, K. C. LIN, and T. B. TANG. "NOVEL SUPERSTRUCTURES OF ALKALI-DOPED C60 FILMS ON Cu(111) AND Ag(111) SURFACES." Surface Review and Letters 14, no. 04 (August 2007): 739–43. http://dx.doi.org/10.1142/s0218625x07010172.
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We report a scanning tunneling microscopy (STM) study of potassium ( K )-doped C 60 ( K x C 60) on Cu (111) and Ag (111), with focus on the observation of novel K -induced superstructures. On Cu (111), K -intercalation leads to various superstructures, i.e., p(3 × 3), p(2 × 2), and a disordered "maze-like" structure. Concomitant removal of C 60-induced substrate reconstruction was also observed. On Ag (111), K -doping induces C 60 reorientation and results in a p(2 × 2) superstructure. All observed superstructures suggest intrinsic inhomogeneity of K -doping in fullerene materials, which must be further understood.
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Han, Wanshui, Xin Xu, Jiajia Wang, Lili Xiao, Kai Zhou, and Xuelian Guo. "Safety Assessment of Coastal Bridge Superstructures with Box Girders under Potential Landslide Tsunamis." Journal of Marine Science and Engineering 11, no. 5 (May 16, 2023): 1062. http://dx.doi.org/10.3390/jmse11051062.
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The superstructure of a coastal bridge is prone to overturn or unseating under a catastrophic tsunami, which seriously affects the post-disaster emergency rescue. In this paper, we establish a safety assessment framework for the superstructure of a bridge with a box girder under a potential landslide tsunami, and apply it to an in-service box girder and Baiyun Slide Complex on the southeast coast of China. First, a meshless numerical approach called Tsunami Squares (TS) is used to predict the movement of landslides and tsunamis. Additionally, we introduce the velocity-weakening basal friction effect in the model to optimize the landslide dynamics. Second, the maximum lateral and vertical wave loads on a box girder can be estimated using the time series of the wave height and velocity in the TS model. Third, we construct a safety evaluation method for the superstructure using the reaction of the bearing as the critical index. The results indicate that the framework developed here provides instructive guidance for evaluating the safety of coastal bridge superstructures during tsunami disasters, and we discuss the influence of the basal friction effect, bridge elevation, and support type on the structural safety.
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Vaipolin, A. A., M. A. Sinitsyn, and A. A. Yakovenko. "Superstructure Ga4InAs5." Physics of the Solid State 43, no. 4 (April 2001): 616–20. http://dx.doi.org/10.1134/1.1365980.
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Dimitrov, S. I., T. M. Apostolova, V. L. Makarov, and I. G. Pashev. "Chromatin superstructure." FEBS Letters 200, no. 2 (May 12, 1986): 322–26. http://dx.doi.org/10.1016/0014-5793(86)81161-9.
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Подлесных, И. С., and С. Ю. Гриднев. "Features of Redistribution of Internal Forces in the Elements of Split Spans of Road Bridges Under the Influence of Solar Radiation." НАУЧНЫЙ ЖУРНАЛ СТРОИТЕЛЬСТВА И АРХИТЕКТУРЫ, no. 3(71) (September 20, 2023): 101–10. http://dx.doi.org/10.36622/vstu.2023.3.71.011.
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Постановка задачи. Неравномерный нагрев от воздействия солнечной радиации может оказывать влияние на напряженно-деформированное состояние пролетных строений. В действующих нормативных документах по проектированию пролетных строений температурное воздействие учитывается упрощенно. Данная область исследования нуждается во всестороннем развитии и детальном изучении. Результаты. Выполнен сравнительный расчет напряженно-деформированного состояния при характерных случаях воздействия солнечной радиации с использованием разработанных конечно-элементных моделей двух типов разрезных пролетных строений с металлическими балками. Выводы. Результаты исследования позволили сделать вывод, что неравномерное изменение температурного поля при воздействии солнечной радиации оказывает влияние на перераспределение внутренних усилий в элементах сталежелезобетонного пролетного строения и металлического пролетного строения с ортотропной плитой. Statement of the problem. Uneven heating from the exposure to solar radiation can affect the stress-strain state of superstructures. In the current regulatory documents on the design of superstructures, the temperature effect is taken into account in a simplified manner. This area of research needs comprehensive development and detailed study. Results. A comparative calculation of the stress-strain state in typical cases of exposure to solar radiation is performed using the developed finite element models of two types of split superstructures with metal beams. Conclusions. The results of the study allowed us to conclude that an uneven change in the temperature field under the influence of solar radiation affects the redistribution of internal forces in the elements of a steel-reinforced concrete superstructure and a metal superstructure with an orthotropic plate.
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Yin, Shu, Rui Xing Li, and Tsugio Sato. "Soft Solution Synthesis and Characterization of Zinc Oxide Films with Nano-Rods and Nano-Screws Superstructures." Advances in Science and Technology 45 (October 2006): 679–84. http://dx.doi.org/10.4028/www.scientific.net/ast.45.679.
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Novel superstructures of zinc oxide thin film with nano-rods and nano-screws were prepared via soft solution route without any polymer additives. The thin film of ZnO could be produced directly on the substrates. The yield of nano-rod and/or nano-screw was almost 100%. Small amount of nano-disk superstructure was also obtained. The superstructures of the film changed depending on the kind of treatment organic solvent such as methanol, butanol, i-propanol, hexane, etc. Monodispersed or symbiotic/multipod ZnO nanorods with hexagonal cross section or screw microstructure were successfully prepared.
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Spivakov, Aleksandr A., Chun-Rong Lin, Yu-Chuan Chang, and Ying-Zhen Chen. "Synthesis of Fe1-xS Nanoparticles with Various Superstructures by a Simple Thermal Decomposition Route and Their Magnetic Properties." Nanomaterials 11, no. 6 (May 30, 2021): 1447. http://dx.doi.org/10.3390/nano11061447.
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Pyrrhotite nanoparticles with 5C and 3C superstructures were synthesized via a simple one-step thermal decomposition method in which hexadecylamine was used as a solvent at various reaction temperatures (TR). Structural analysis showed that at TR = 360 °C, almost uniform in size and shape Fe7S8 nanoparticles with 3C superstructure are formed, and an increase in the reaction temperature leads to the formation of Fe9S10 nanoparticles (5C superstructure), herewith a significant increase in the size of nanoparticles is observed. High-temperature magnetic measurements in 5 repeated heating-cooling cycles revealed that after the first heating branch in the Fe9S10 samples, the λ—Peak transition disappears, and the magnetization has a Weiss-type behavior characteristic of the Fe7S8 sample. The change in the behavior of magnetization can be explained by the redistribution of iron vacancies, which changes the initial phase composition of nanoparticles.
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Reyes-Gasga, J. "On the 2√2 a × 2√2 a supestructure phase." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 4 (August 1990): 110–11. http://dx.doi.org/10.1017/s0424820100173686.
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Recently Reyes-Gasga et. al. have studied the superstructures phases produced by the ordering of vacancies (or oxygen) in the YBa2Cu3Ox, supercondutor compound. In these papers they also discussed briefly a posible interpretation of the diffraction pattern based on a square unit cell with edges 2√2 a × 2√2 a, where a=0.38nm (fig. 1e), and suggested that this pattern might not be due to a pure vacancy ordered structure but should presumably be attributed to a deformation modulated superstructure of a highly oxygen deficient perovskite phase. This diffraction pattern was studied previously in detail and it has been attributed to a number of oxygen vacancy ordered orthorhombic structures with different oxygen content. In this report I shall inform about some experiments concerning with the formation conditions and temperature behavior of the phase that produces this pattern.Heating the YBa2Cu3O7, superconductor compound in situ in the TEM is possible to obtain not only diffuse streaks and superstructure spots unless also new arrays of superstructure spots. Therefore the experimental procedure consists in the in situ heating of this compound in the JEDL 200C TEM using a heating holder. It is well known that the exact temperature value in this kind of experiments is hard to specify and here only an average temperature range is reported.
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Kong, Qing Mei, and Hong Ju Lv. "Study on the Splicing Method between New and Old Bridges." Applied Mechanics and Materials 204-208 (October 2012): 2257–60. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.2257.
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It’s very necessary to do research on bridge splicing method, because it must refer to splicing problems between new and old bridge during expressway widening engineering. Now there are three main splicing methods: non-splicing for both superstructures and substructures, splicing of superstructures and non-splicing of substructures and splicing for both superstructures and substructures. Now splicing of superstructure and non-splicing of substructure is used more than other two splicing methods. Each splicing method has several different new construction technologies and their aims are to decrease the splicing disease. At present our country has accumulated lots of splicing engineering experience, so the following engineering should assimilate former experience and do incessant improvement and reformation.
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Liu, Qingda, Peilei He, Hongde Yu, Lin Gu, Bing Ni, Dong Wang, and Xun Wang. "Single molecule–mediated assembly of polyoxometalate single-cluster rings and their three-dimensional superstructures." Science Advances 5, no. 7 (July 2019): eaax1081. http://dx.doi.org/10.1126/sciadv.aax1081.
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The assembly of atomically precise clusters into superstructures has tremendous potential in structural tunability and applications. Here, we report a series of single-cluster nanowires, single-cluster nanorings, and three-dimensional superstructure assemblies built by POM clusters. By stepwise tuning of interactions at molecular levels, the configurations can be varied from single-cluster nanowires to nanorings. A series of single-cluster nanostructures in different configurations can be achieved with up to 15 kinds of POM clusters. The single-cluster nanowires and three-dimensional superstructures perform enhanced activity in the catalytic and electrochemical sensing fields, illustrating the universal functionality of single-cluster assemblies.
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Ayna, Mustafa, and Søren Jepsen. "A Retrospective Evaluation of 5 Years of Clinical Results of Metal–Ceramic vs. Monolithic Zirconia Superstructures in Maxillary All-on-4TM Concept." Journal of Clinical Medicine 13, no. 2 (January 18, 2024): 557. http://dx.doi.org/10.3390/jcm13020557.
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The aim of the current study was to present the clinical and radiological outcomes of monolithic zirconia superstructures compared to the metal–ceramic ones in the All-on-4 concept for the prosthetic rehabilitation of the maxillae. A total of 30 patients were subdivided into groups according to their superstructure type (metal–ceramic (n = 15) or monolithic zirconia (n = 15)). All implants were functionally loaded within 24 h after insertion with provisional acrylic superstructures. Prosthetic complications, marginal bone loss, plaque accumulation, probing pocket depth, bleeding on probing, and bite force were documented over a period of 5 years. Marginal bone loss around the implants of the ceramic group remained well over the five years (1.21 ± 0.23 mm). However, marginal bone loss was significantly lower around the implants in the monolithic zirconia group (0.22 ± 0.14 mm) (p < 0.001). Bleeding on probing, plaque accumulation, and probing pocket depth values were correlated with marginal bone loss. Among all evaluated parameters, no differences could be detected in terms of the angulation of the implants. Detachment or chipping was observed in seven cases in the metal–ceramic superstructure group. In all cases, dentures were removed and repaired in the laboratory. In the monolithic zirconia group, chipping was detected after one year in two cases, after two years in four cases, and after five years in one case and could be managed by polishing in situ. Monolithic zirconia superstructures presented superior results regarding the parameters evaluated.
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Poliakov, V., Zhang Nan, V. Saurin, and Dang Ngoc Thanh. "Running Safety of a High-Speed Train within a Bridge Zone." International Journal of Structural Stability and Dynamics 20, no. 11 (September 3, 2020): 2050116. http://dx.doi.org/10.1142/s0219455420501163.
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This paper describes the issue of validity of running safety criterion on high-speed railways (HSR). In this research, the 2D model of ‘car–track–bridge’ system is used. A feature of HSR is the practical reaching of the critical speeds that cause resonance of bridge superstructures. The Eurocode establishes the limit of bridge superstructure acceleration below 5[Formula: see text]m/s2 in case of nonballasted track. This limit does not suit in certain conditions such as resonance of the superstructure that is permitted in Eurocode. In this case, there is no correlation between acceleration limit and firm wheel–rail contact. The numerical analysis shows repeated wheel lift-off during train passing a bridge zone. It is resonance of the bridge deck that causes this effect because without resonance, the running train is safe. Lower damping in nonballasted track increases resonant vibration influence.
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Xiong, Zhihua, Jianbing Chen, Chen Liu, Jinping Li, and Wenwen Li. "Bridge’s Overall Structural Scheme Analysis in High Seismic Risk Permafrost Regions." Civil Engineering Journal 8, no. 7 (July 1, 2022): 1316–27. http://dx.doi.org/10.28991/cej-2022-08-07-01.
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The mechanism of pile-soil reaction in frozen ground is not clear at present, but it is obvious that the reduction of dead weight will be beneficial to the seismic resistance of bridges. In view of the limited bridge engineering practice in high seismic risk permafrost regions, the paper addressed the structural performance of the superstructure and its effect on piles in these special regions. Four superstructures with different dead weights were compared, and bored piles were designed. Numerical simulations were implemented to investigate the refreezing time of the bored pile foundation. The concrete pile cooled rapidly in the first two days. The refreezing times of the GFRP, prestressed concrete T-girder, integrated composite girder, and MVFT girder were 15d, 37d, 39d, and 179d, respectively. The refreezing time of a pile in the same soil layer is mainly affected by the pile’s diameter, and it is significantly correlated to the square of the pile diameter. It reflects that the selection of bridge superstructures in the permafrost region is very important, which has been ignored in previous studies. The pile length and pile diameter of the lighter superstructure can be shorter and smaller to reduce the refreezing time and alleviate the thermal disturbance. Doi: 10.28991/CEJ-2022-08-07-01 Full Text: PDF