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Sample records for building cloaking structures

  1. Homogeneous optical cloak constructed with uniform layered structures

    DEFF Research Database (Denmark)

    Zhang, Jingjing; Liu, Liu; Luo, Yu

    2011-01-01

    , the majority of the invisibility cloaks reported so far have a spatially varying refractive index which requires complicated design processes. Besides, the size of the hidden object is usually small relative to that of the cloak device. Here we report the experimental realization of a homogenous invisibility...

  2. A thermal ground cloak

    International Nuclear Information System (INIS)

    Yang, Tianzhi; Wu, Qinghe; Xu, Weikai; Liu, Di; Huang, Lujun; Chen, Fei

    2016-01-01

    The thermal cloak has been a long-standing scientific dream of researchers and engineers. Recently thermal metamaterials with man-made micro-structure have been presented based on the principle of transformation optics (TO). This new concept has received considerable attention, which is a powerful tool for manipulating heat flux in thermal imaging systems. However, the inherent material singularity has long been a captivation of experimental realization. As an alternative method, the scattering-cancellation-based cloak (or bi-layer thermal cloak) has been presented to remove the singularity for achieving the same cloaking performance. Nevertheless, such strategy needs prerequisite knowledge (geometry and conductivity) of the object to be cloaked. In this paper, a new thermal ground cloak is presented to overcome the limitations. The device is designed, fabricated and measured to verify the thermal cloaking performance. We experimentally show that the remarkably low complexity of the device can fully and effectively be manipulated using realizable transformation thermal devices. More importantly, this thermal ground cloak is designed to exclude heat flux without knowing the information of the cloaked object. - Highlights: • We present the first thermal carpet cloak. • The carpet can thermally cloak any shaped object without knowing the properties of the object to be cloaked. • Excellent agreements between simulation and experiment are observed.

  3. Electrostatic cloaking of surface structure for dynamic wetting

    Science.gov (United States)

    Shiomi, Junichiro; Nita, Satoshi; Do-Quang, Minh; Wang, Jiayu; Chen, Yu-Chung; Suzuki, Yuji; Amberg, Gustav

    2017-11-01

    Dynamic wetting problems are fundamental to the understanding of the interaction between liquids and solids. Even in a superficially simple experimental situation, such as a droplet spreading over a dry surface, the result may depend not only on the liquid properties but also strongly on the substrate-surface properties; even for macroscopically smooth surfaces, the microscopic geometrical roughness can be important. In addition, as surfaces may often be naturally charged, or electric fields are used to manipulate fluids, electric effects are crucial components that influence wetting phenomena. Here we investigate the interplay between electric forces and surface structures in dynamic wetting. While surface microstructures can significantly hinder the spreading, we find that the electrostatics can ``cloak'' the microstructures, i.e. deactivate the hindering. We identify the physics in terms of reduction in contact-line friction, which makes the dynamic wetting inertial force dominant and insensitive to the substrate properties. This work was financially supported in part by, the Japan Society for the Promotion of Science, Swedish Governmental Agency for Innovation Systems, and the Japan Science and Technology Agency.

  4. Broadband cloaking using composite dielectrics

    Directory of Open Access Journals (Sweden)

    Ruey-Bing Hwang

    2011-03-01

    Full Text Available In this paper, we present a novel cloaking structure that is able to make a metallic block invisible in a metallic waveguide. Such a cloak is made up of a stack of commonly used dielectric slabs. We carry out the numerical simulation and observe the detour of the vector Poynting power through the cloak. Moreover, the experiment is conducted for measuring the scattering characteristics including the reflection and transmission coefficients. The great improvement in the transmission coefficient in a broad bandwidth after cloaking is demonstrated. Significantly, the theory of mode conversion is developed for explaining the cloaking phenomenon.

  5. Spatial dispersion of index components required for building invisibility cloak medium from photonic crystals

    Science.gov (United States)

    Jamilan, Saeid; Semouchkin, George; Gandji, Navid P.; Semouchkina, Elena

    2018-04-01

    The opportunities to use dielectric photonic crystals (PhCs) as the media of cylindrical invisibility cloaks, designed using transformation optics (TO) concepts, are investigated. It is shown that TO-based prescriptions for radial index dispersion, responsible for turning waves around hidden objects, can be dropped if the PhC media support self-collimation of waves in bent crystals. Otherwise, to provide prescribed anisotropy of index dispersion, it is possible to employ PhCs with rectangular lattices. It is found, however, that at acceptable cloak thicknesses, modifications of crystal parameters do not allow for achieving the prescribed level of index anisotropy. This problem is solved by finding the reduced spatial dispersion law for the radial index component, which is characterized by decreased against TO-prescriptions values near the target and increased values in outer layers of the cloak. The cloak utilizing reduced prescriptions for indices is shown to perform almost as efficiently as a TO-based cloak, in terms of both wave front restoration behind the target and reducing the total scattering cross-width of the target.

  6. Parabolic transformation cloaks for unbounded and bounded cloaking of matter waves

    Science.gov (United States)

    Chang, Yu-Hsuan; Lin, De-Hone

    2014-01-01

    Parabolic quantum cloaks with unbounded and bounded invisible regions are presented with the method of transformation design. The mass parameters of particles for perfect cloaking are shown to be constant along the parabolic coordinate axes of the cloaking shells. The invisibility performance of the cloaks is inspected from the viewpoints of waves and probability currents. The latter shows the controllable characteristic of a probability current by a quantum cloak. It also provides us with a simpler and more efficient way of exhibiting the performance of a quantum cloak without the solutions of the transformed wave equation. Through quantitative analysis of streamline structures in the cloaking shell, one defines the efficiency of the presented quantum cloak in the situation of oblique incidence. The cloaking models presented here give us more choices for testing and applying quantum cloaking.

  7. Temperature-Controlled Chameleonlike Cloak

    Science.gov (United States)

    Peng, Ruiguang; Xiao, Zongqi; Zhao, Qian; Zhang, Fuli; Meng, Yonggang; Li, Bo; Zhou, Ji; Fan, Yuancheng; Zhang, Peng; Shen, Nian-Hai; Koschny, Thomas; Soukoulis, Costas M.

    2017-01-01

    Invisibility cloaking based on transformation optics has brought about unlimited space for reverie. However, the design and fabrication of transformation-optics-based cloaks still remain fairly challenging because of the complicated, even extreme, material prescriptions, including its meticulously engineered anisotropy, inhomogeneity and singularity. And almost all the state-of-the-art cloaking devices work within a narrow and invariable frequency band. Here, we propose a novel mechanism for all-dielectric temperature-controllable cloaks. A prototype device was designed and fabricated with SrTiO3 ferroelectric cuboids as building blocks, and its cloaking effects were successfully demonstrated, including its frequency-agile invisibility by varying temperature. It revealed that the predesignated cloaking device based on our proposed strategy could be directly scaled in dimensions to operate at different frequency regions, without the necessity for further efforts of redesign. Our work opens the door towards the realization of tunable cloaking devices for various practical applications and provides a simple strategy to readily extend the cloaking band from microwave to terahertz regimes without the need for reconfiguration.

  8. Temperature-Controlled Chameleonlike Cloak

    Directory of Open Access Journals (Sweden)

    Ruiguang Peng

    2017-03-01

    Full Text Available Invisibility cloaking based on transformation optics has brought about unlimited space for reverie. However, the design and fabrication of transformation-optics-based cloaks still remain fairly challenging because of the complicated, even extreme, material prescriptions, including its meticulously engineered anisotropy, inhomogeneity and singularity. And almost all the state-of-the-art cloaking devices work within a narrow and invariable frequency band. Here, we propose a novel mechanism for all-dielectric temperature-controllable cloaks. A prototype device was designed and fabricated with SrTiO_{3} ferroelectric cuboids as building blocks, and its cloaking effects were successfully demonstrated, including its frequency-agile invisibility by varying temperature. It revealed that the predesignated cloaking device based on our proposed strategy could be directly scaled in dimensions to operate at different frequency regions, without the necessity for further efforts of redesign. Our work opens the door towards the realization of tunable cloaking devices for various practical applications and provides a simple strategy to readily extend the cloaking band from microwave to terahertz regimes without the need for reconfiguration.

  9. Transformation optics and invisibility cloaks

    DEFF Research Database (Denmark)

    Qiu, Min; Yan, Min; Yan, Wei

    2008-01-01

    In this paper, we briefly summarize the theory of transformation optics and introduce its application in achieving perfect invisibility cloaking. In particular, we theoretically show how the task of realizing cylindrical invisibility cloaks can be eased by using either structural approximation...

  10. Electromagnetic Invisibility of Elliptic Cylinder Cloaks

    International Nuclear Information System (INIS)

    Kan, Yao; Chao, Li; Fang, Li

    2008-01-01

    Structures with unique electromagnetic properties are designed based on the approach of spatial coordinate transformations of Maxwell's equations. This approach is applied to scheme out invisible elliptic cylinder cloaks, which provide more feasibility for cloaking arbitrarily shaped objects. The transformation expressions for the anisotropic material parameters and the field distribution are derived. The cloaking performances of ideal and lossy elliptic cylinder cloaks are investigated by finite element simulations. It is found that the cloaking performance will degrade in the forward direction with increasing loss. (fundamental areas of phenomenology (including applications))

  11. Electronically cloaked nanoparticles

    Science.gov (United States)

    Shen, Wenqing

    The concept of electronic cloaking is to design objects invisible to conduction electrons. The approach of electronic cloaking has been recently suggested to design invisible nanoparticle dopants with electronic scattering cross section smaller than 1% of the physical cross section (pi a2), and therefore to enhance the carrier mobility of bulk materials. The proposed nanoparticles have core-shell structures. The dopants are incorporated inside the core, while the shell layer serves both as a spacer to separate the charge carriers from their parent atoms and as a cloaking shell to minimize the scattering cross section of the electrons from the ionized nanoparticles. Thermoelectric materials are usually highly doped to have enough carrier density. Using invisible dopants could achieve larger thermoelectric power factors by enhancing the electronic mobility. Core-shell nanoparticles show an advantage over one-layer nanoparticles, which are proposed in three-dimensional modulation doping. However designing such nanoparticles is not easy as there are too many parameters to be considered. This thesis first shows an approach to design hollow nanoparticles by applying constrains on variables. In the second part, a simple mapping approach is introduced where one can identify possible core-shell particles by comparing the dimensionless parameters of chosen materials with provided maps. In both parts of this work, several designs with realistic materials were made and proven to achieve electronic cloaking. Improvement in the thermoelectric power factor compared to the traditional impurity doping method was demonstrated in several cases.

  12. Homogenous isotropic invisible cloak based on geometrical optics.

    Science.gov (United States)

    Sun, Jingbo; Zhou, Ji; Kang, Lei

    2008-10-27

    Invisible cloak derived from the coordinate transformation requires its constitutive material to be anisotropic. In this work, we present a cloak of graded-index isotropic material based on the geometrical optics theory. The cloak is realized by concentric multilayered structure with designed refractive index to achieve the low-scattering and smooth power-flow. Full-wave simulations on such a design of a cylindrical cloak are performed to demonstrate the cloaking ability to incident wave of any polarization. Using normal nature material with isotropy and low absorption, the cloak shows light on a practical path to stealth technology, especially that in the optical range.

  13. Building structures

    CERN Document Server

    Ambrose, James

    2011-01-01

    James Ambrose is Editor of the Parker/Ambrose Series of Simplified Design Guides. He practiced as an architect in California and Illinois and as a structural engineer in Illinois. He was a professor of architecture at the University of Southern California. Patrick Tripeny is an Associate Professor, former director of the School of Architecture, and the current Director of the Center for Teaching and Learning Excellence at the University of Utah. He is a licensed architect in California. He has been the recipient of a number of teaching awards at the local and national level for his work in teaching structures and design. With James Ambrose, he is the coauthor of Simplified Engineering for Architects and Builders, Eleventh Edition; Simplified Design of Steel Structures, Eighth Edition; Simplified Design of Concrete Structures, Eighth Edition; and Simplified Design of Wood Structures, Sixth Edition, all published by Wiley.

  14. Geometry and Cloaking Devices

    Science.gov (United States)

    Ochiai, T.; Nacher, J. C.

    2011-09-01

    Recently, the application of geometry and conformal mappings to artificial materials (metamaterials) has attracted the attention in various research communities. These materials, characterized by a unique man-made structure, have unusual optical properties, which materials found in nature do not exhibit. By applying the geometry and conformal mappings theory to metamaterial science, it may be possible to realize so-called "Harry Potter cloaking device". Although such a device is still in the science fiction realm, several works have shown that by using such metamaterials it may be possible to control the direction of the electromagnetic field at will. We could then make an object hidden inside of a cloaking device. Here, we will explain how to design invisibility device using differential geometry and conformal mappings.

  15. A multi-cloak bifunctional device

    Science.gov (United States)

    Raza, Muhammad; Liu, Yichao; Ma, Yungui

    2015-01-01

    Invisibility cloak has attracted the attention of electromagnetic researchers due to its magical properties and marvelous potential applications in the field of applied physics and engineering. Recently, a multiphysics cloaking has put the new spirit into this field. In this paper, we introduce a device, composed of three shells and each shell works as an invisibility cloak for a specific physical phenomenon. Following this technique, a number of cloaks with different implementation approaches can be proposed for distinct physical phenomena in a single structure. Here, we restrict ourselves for the case of two physical behaviors: thermal and electrical conductivities. This type of multi-cloaking structure can be best used in mechanically designed structures to better control heating and electrical effects.

  16. Invisibility cloak with image projection capability.

    Science.gov (United States)

    Banerjee, Debasish; Ji, Chengang; Iizuka, Hideo

    2016-12-13

    Investigations of invisibility cloaks have been led by rigorous theories and such cloak structures, in general, require extreme material parameters. Consequently, it is challenging to realize them, particularly in the full visible region. Due to the insensitivity of human eyes to the polarization and phase of light, cloaking a large object in the full visible region has been recently realized by a simplified theory. Here, we experimentally demonstrate a device concept where a large object can be concealed in a cloak structure and at the same time any images can be projected through it by utilizing a distinctively different approach; the cloaking via one polarization and the image projection via the other orthogonal polarization. Our device structure consists of commercially available optical components such as polarizers and mirrors, and therefore, provides a significant further step towards practical application scenarios such as transparent devices and see-through displays.

  17. Optimized cylindrical invisibility cloak with minimum layers of non-magnetic isotropic materials

    International Nuclear Information System (INIS)

    Yu Zhenzhong; Feng Yijun; Xu Xiaofei; Zhao Junming; Jiang Tian

    2011-01-01

    We present optimized design of cylindrical invisibility cloak with minimum layers of non-magnetic isotropic materials. Through an optimization procedure based on genetic algorithm, simpler cloak structure and more realizable material parameters can be achieved with better cloak performance than that of an ideal non-magnetic cloak with a reduced set of parameters. We demonstrate that a cloak shell with only five layers of two normal materials can result in an average 20 dB reduction in the scattering width for all directions when covering the inner conducting cylinder with the cloak. The optimized design can substantially simplify the realization of the invisibility cloak, especially in the optical range.

  18. Experimental and computational studies of electromagnetic cloaking at microwaves

    Science.gov (United States)

    Wang, Xiaohui

    An invisibility cloak is a device that can hide the target by enclosing it from the incident radiation. This intriguing device has attracted a lot of attention since it was first implemented at a microwave frequency in 2006. However, the problems of existing cloak designs prevent them from being widely applied in practice. In this dissertation, we try to remove or alleviate the three constraints for practical applications imposed by loosy cloaking media, high implementation complexity, and small size of hidden objects compared to the incident wavelength. To facilitate cloaking design and experimental characterization, several devices and relevant techniques for measuring the complex permittivity of dielectric materials at microwave frequencies are developed. In particular, a unique parallel plate waveguide chamber has been set up to automatically map the electromagnetic (EM) field distribution for wave propagation through the resonator arrays and cloaking structures. The total scattering cross section of the cloaking structures was derived based on the measured scattering field by using this apparatus. To overcome the adverse effects of lossy cloaking media, microwave cloaks composed of identical dielectric resonators made of low loss ceramic materials are designed and implemented. The effective permeability dispersion was provided by tailoring dielectric resonator filling fractions. The cloak performances had been verified by full-wave simulation of true multi-resonator structures and experimental measurements of the fabricated prototypes. With the aim to reduce the implementation complexity caused by metamaterials employment for cloaking, we proposed to design 2-D cylindrical cloaks and 3-D spherical cloaks by using multi-layer ordinary dielectric material (epsilon r>1) coating. Genetic algorithm was employed to optimize the dielectric profiles of the cloaking shells to provide the minimum scattering cross sections of the cloaked targets. The designed cloaks can

  19. Regular scattering patterns from near-cloaking devices and their implications for invisibility cloaking

    International Nuclear Information System (INIS)

    Kocyigit, Ilker; Liu, Hongyu; Sun, Hongpeng

    2013-01-01

    In this paper, we consider invisibility cloaking via the transformation optics approach through a ‘blow-up’ construction. An ideal cloak makes use of singular cloaking material. ‘Blow-up-a-small-region’ construction and ‘truncation-of-singularity’ construction are introduced to avoid the singular structure, however, giving only near-cloaks. The study in the literature is to develop various mechanisms in order to achieve high-accuracy approximate near-cloaking devices, and also from a practical viewpoint to nearly cloak an arbitrary content. We study the problem from a different viewpoint. It is shown that for those regularized cloaking devices, the corresponding scattering wave fields due to an incident plane wave have regular patterns. The regular patterns are both a curse and a blessing. On the one hand, the regular wave pattern betrays the location of a cloaking device which is an intrinsic defect due to the ‘blow-up’ construction, and this is particularly the case for the construction by employing a high-loss layer lining. Indeed, our numerical experiments show robust reconstructions of the location, even by implementing the phaseless cross-section data. The construction by employing a high-density layer lining shows a certain promising feature. On the other hand, it is shown that one can introduce an internal point source to produce the canceling scattering pattern to achieve a near-cloak of an arbitrary order of accuracy. (paper)

  20. Elastodynamic cloaking and field enhancement for soft spheres

    Science.gov (United States)

    Diatta, Andre; Guenneau, Sebastien

    2016-11-01

    We propose a spherical cloak described by a non-singular asymmetric elasticity tensor {C} depending upon a small parameter η, that defines the softness of a region one would like to conceal from elastodynamic waves. By varying η, we generate a class of soft spheres dressed by elastodynamic cloaks, which are shown to considerably reduce the scattering of the soft spheres. Importantly, such cloaks also provide some wave protection except for a countable set of frequencies, for which some large elastic field enhancement can be observed within the soft spheres. Through an investigation of trapped modes in elasticity, we supply a good approximation of such Mie-type resonances by some transcendental equation. Our results, unlike previous studies that focused merely on the invisibility aspects, shed light on potential pitfalls of elastodynamic cloaks for earthquake protection designed via geometric transforms: a seismic cloak needs to be designed in such a way that its inner resonances differ from eigenfrequencies of the building one wishes to protect. In order to circumvent this downfall of field enhancement inside the cloaked area, we introduce a novel generation of cloaks, named here, mixed cloaks. Such mixed cloaks consist of a shell that detours incoming waves, hence creating an invisibility region, and of a perfectly matched layer (PML, located at the inner boundary of the cloaks) that absorbs residual wave energy in such a way that aforementioned resonances in the soft sphere are strongly attenuated. The designs of mixed cloaks with a non-singular elasticity tensor combined with an inner PML and non-vanishing density bring seismic cloaks one step closer to a practical implementation. Note in passing that the concept of mixed cloaks also applies in the case of singular cloaks and can be translated in other wave areas for a similar purpose (i.e. to smear down inner resonances within the invisibility region).

  1. Modern frame structure buildings

    Directory of Open Access Journals (Sweden)

    В. М. Першаков

    2013-07-01

    Full Text Available The article deals with the design, construction and implementation of reinforced concrete frame structures with span 18, 21 m for agricultural production buildings, hall-premises of public buildings and buildings of agricultural aviation. Structures are prefabricated frame buildings and have such advantages as large space inside the structure and lower cost compared with other facilities with same purpose

  2. Diffusive-light invisibility cloak for transient illumination

    Science.gov (United States)

    Orazbayev, B.; Beruete, M.; Martínez, A.; García-Meca, C.

    2016-12-01

    Invisibility in a diffusive-light-scattering medium has been recently demonstrated by employing a scattering-cancellation core-shell cloak. Unlike nondiffusive cloaks, such a device can be simultaneously macroscopic, broadband, passive, polarization independent, and omnidirectional. Unfortunately, it has been verified that this cloak, as well as more sophisticated ones based on transformation optics, fail under pulsed illumination, invalidating their use for a variety of applications. Here, we introduce a different approach based on unimodular transformations that enables the construction of unidirectional diffusive-light cloaks exhibiting a perfect invisibility effect, even under transient conditions. Moreover, we demonstrate that a polygonal cloak can extend this functionality to multiple directions with a nearly ideal behavior, while preserving all other features. We propose and numerically verify a simple cloak realization based on a layered stack of two isotropic materials. The studied devices have several applications not addressable by any of the other cloaks proposed to date, including shielding from pulse-based detection techniques, cloaking undesired scattering elements in time-of-flight imaging or high-speed communication systems for diffusive environments, and building extreme optical security features. The discussed cloaking strategy could also be applied to simplify the implementation of thermal cloaks.

  3. Ultrabroadband elastic cloaking in thin plates.

    Science.gov (United States)

    Farhat, Mohamed; Guenneau, Sebastien; Enoch, Stefan

    2009-07-10

    Control of waves with metamaterials is of great topical interest, and is fueled by rapid progress in broadband acoustic and electromagnetic cloaks. We propose a design for a cloak to control bending waves propagating in isotropic heterogeneous thin plates. This is achieved through homogenization of a multilayered concentric coating filled with piecewise constant isotropic elastic material. Significantly, our cloak displays no phase shift for both backward and forward scattering. To foster experimental efforts, we provide a simplified design of the cloak which is shown to work in a more than two-octave frequency range (30 Hz to 150 Hz) when it consists of 10 layers using only 6 different materials overall. This metamaterial should be easy to manufacture, with potential applications ranging from car industry to anti-earthquake passive systems for smart buildings, depending upon the plate dimensions and wavelengths.

  4. Anti-sound and Acoustical Cloaks

    Directory of Open Access Journals (Sweden)

    Veturia CHIROIU

    2016-12-01

    Full Text Available The principles by which the acoustics can be mimicked in order to reduce or cancel the vibrational field are based on anti-sound concept which can be materialized by acoustic cloaks. Geometric transformations open an elegant way towards the unconstrained control of sound through acoustic metamaterials. Acoustic cloaks can be achieved through geometric transformations which bring exotic metamaterial properties into the acoustic equations. Our paper brings new ideas concerning the technological keys for manufacturing of novel metamaterials based on the spatial compression of Cantor structures, and the architecture of 3D acoustic cloaks in a given frequency band, with application to architectural acoustics.

  5. Gravitational lensing as a mechanism for effective cloaking

    International Nuclear Information System (INIS)

    Tippett, Benjamin K.

    2011-01-01

    In light of the surge in popularity of electromagnetic cloaking devices, we consider whether it is possible to use general relativity to cloak a volume of spacetime through gravitational lensing. We explore the cloaking properties of a spacetime through a ray-tracing procedure, wherein we plot the spatial trajectories of a congruence of initially parallel null geodesics as they cross the geometry. In this context, a cloaking device would cause all of the null geodesics in an initially parallel congruence incident upon the cloaking geometry to circumnavigate an internal region, and as the geodesics emerge from the geometry, they regain their original configuration. Thus, if gravitational lensing were used as a mechanism for cloaking, the internal region would be causally isolated from the external spacetime. For this reason, we propose an effective cloaking geometry wherein (only) most of ingoing null geodesics will splay away from a central region, and then regain their initial configuration as they exit the geometry. Thus, a compact object sitting within the effective cloaking geometry will impede a smaller cross section of the null congruence, and therefore appear optically smaller from all sides. We build our effective cloaking geometry by connecting a Minkowski spacetime exterior to a spherically symmetric, curved spacetime along a timelike hypersurface of constant radius using the Israel junction conditions. The junction conditions require a shell of matter of infinitesimal width confined to the junction surface. The matter required to build such a spacetime must violate the null energy condition.

  6. Electromagnetic cloaking in higher order spherical cloaks

    Science.gov (United States)

    Sidhwa, H. H.; Aiyar, R. P. R. C.; Kulkarni, S. V.

    2017-06-01

    The inception of transformation optics has led to the realisation of the invisibility devices for various applications, one of which is spherical cloaking. In this paper, a formulation for a higher-order spherical cloak has been proposed to reduce its physical thickness significantly by introducing a nonlinear relation between the original and transformed coordinate systems and it has been verified using the ray tracing approach. Analysis has been carried out to observe the anomalies in the variation of refractive index for higher order cloaks indicating the presence of poles in the relevant equations. Furthermore, a higher-order spherical cloak with predefined values of the material characteristics on its inner and outer surfaces has been designed for practical application.

  7. Interior acoustic cloak

    OpenAIRE

    Wael Akl; A. Baz

    2014-01-01

    Acoustic cloaks have traditionally been intended to externally surround critical objects to render these objects acoustically invisible. However, in this paper, the emphasis is placed on investigating the application of the acoustic cloaks to the interior walls of acoustic cavities in an attempt to minimize the noise levels inside these cavities. In this manner, the acoustic cloaks can serve as a viable and efficient alternative to the conventional passive noise attenuation treatments which a...

  8. Coordinate transformations and matter waves cloaking

    International Nuclear Information System (INIS)

    Mohammadi, G.R.; Moghaddam, A.G.; Mohammadkhani, R.

    2016-01-01

    Transformation method provides an efficient tool to control wave propagation inside the materials. Using the coordinate transformation approach, we study invisibility cloaks with sphere, cylinder and ellipsoid structures for electronic waves propagation. The underlying physics behind this investigation is the fact that Schrödinger equation with position dependent mass tensor and potentials has a covariant form which follows the coordinate transformation. Using this technique we obtain the exact spatial form of the mass tensor and potentials for a variety of cloaks with different shapes. - Highlights: • Invisibility cloaks for matter waves with three different geometries. • Exact analytical form of the effective mass tensor and potential. • Analogy between cloaking for quantum mechanical waves with classical electromagnetic waves. • Possible experimental realization in engineered semiconducting structures.

  9. Cloaking through cancellation of diffusive wave scattering

    KAUST Repository

    Farhat, Mohamed

    2016-08-10

    A new cloaking mechanism, which makes enclosed objects invisible to diffusive photon density waves, is proposed. First, diffusive scattering from a basic core-shell geometry, which represents the cloaked structure, is studied. The conditions of scattering cancellation in a quasi-static scattering regime are derived. These allow for tailoring the diffusivity constant of the shell enclosing the object so that the fields scattered from the shell and the object cancel each other. This means that the photon flow outside the cloak behaves as if the cloaked object were not present. Diffusive light invisibility may have potential applications in hiding hot spots in infrared thermography or tissue imaging. © 2016 The Author(s) Published by the Royal Society. All rights reserved.

  10. Interior acoustic cloak

    Directory of Open Access Journals (Sweden)

    Wael Akl

    2014-12-01

    Full Text Available Acoustic cloaks have traditionally been intended to externally surround critical objects to render these objects acoustically invisible. However, in this paper, the emphasis is placed on investigating the application of the acoustic cloaks to the interior walls of acoustic cavities in an attempt to minimize the noise levels inside these cavities. In this manner, the acoustic cloaks can serve as a viable and efficient alternative to the conventional passive noise attenuation treatments which are invariably heavy and bulky. The transformation acoustics relationships that govern the operation of this class of interior acoustic cloaks are presented. Physical insights are given to relate these relationships to the reasons behind the effectiveness of the proposed interior acoustic cloaks. Finite element models are presented to demonstrate the characteristics of interior acoustic cloaks used in treating the interior walls of circular and square cavities both in the time and frequency domains. The obtained results emphasize the effectiveness of the proposed interior cloaks in eliminating the reflections of the acoustic waves from the walls of the treated cavities and thereby rendering these cavities acoustically quiet. It is important to note here that the proposed interior acoustic cloaks can find applications in acoustic cavities such as aircraft cabins and auditoriums as well as many other critical applications.

  11. Molding acoustic, electromagnetic and water waves with a single cloak

    KAUST Repository

    Xu, Jun

    2015-06-09

    We describe two experiments demonstrating that a cylindrical cloak formerly introduced for linear surface liquid waves works equally well for sound and electromagnetic waves. This structured cloak behaves like an acoustic cloak with an effective anisotropic density and an electromagnetic cloak with an effective anisotropic permittivity, respectively. Measured forward scattering for pressure and magnetic fields are in good agreement and provide first evidence of broadband cloaking. Microwave experiments and 3D electromagnetic wave simulations further confirm reduced forward and backscattering when a rectangular metallic obstacle is surrounded by the structured cloak for cloaking frequencies between 2.6 and 7.0 GHz. This suggests, as supported by 2D finite element simulations, sound waves are cloaked between 3 and 8 KHz and linear surface liquid waves between 5 and 16 Hz. Moreover, microwave experiments show the field is reduced by 10 to 30 dB inside the invisibility region, which suggests the multi-wave cloak could be used as a protection against water, sonic or microwaves. © 2015, Nature Publishing Group. All rights reserved.

  12. Molding acoustic, electromagnetic and water waves with a single cloak.

    Science.gov (United States)

    Xu, Jun; Jiang, Xu; Fang, Nicholas; Georget, Elodie; Abdeddaim, Redha; Geffrin, Jean-Michel; Farhat, Mohamed; Sabouroux, Pierre; Enoch, Stefan; Guenneau, Sébastien

    2015-06-09

    We describe two experiments demonstrating that a cylindrical cloak formerly introduced for linear surface liquid waves works equally well for sound and electromagnetic waves. This structured cloak behaves like an acoustic cloak with an effective anisotropic density and an electromagnetic cloak with an effective anisotropic permittivity, respectively. Measured forward scattering for pressure and magnetic fields are in good agreement and provide first evidence of broadband cloaking. Microwave experiments and 3D electromagnetic wave simulations further confirm reduced forward and backscattering when a rectangular metallic obstacle is surrounded by the structured cloak for cloaking frequencies between 2.6 and 7.0 GHz. This suggests, as supported by 2D finite element simulations, sound waves are cloaked between 3 and 8 KHz and linear surface liquid waves between 5 and 16 Hz. Moreover, microwave experiments show the field is reduced by 10 to 30 dB inside the invisibility region, which suggests the multi-wave cloak could be used as a protection against water, sonic or microwaves.

  13. Molding acoustic, electromagnetic and water waves with a single cloak

    KAUST Repository

    Xu, Jun; Jiang, Xu; Fang, Nicholas; Georget, Elodie; Abdeddaim, Redha; Geffrin, Jean Michel; Farhat, Mohamed; Sabouroux, Pierre; Enoch, Stefan; Guenneau, Sé bastien

    2015-01-01

    We describe two experiments demonstrating that a cylindrical cloak formerly introduced for linear surface liquid waves works equally well for sound and electromagnetic waves. This structured cloak behaves like an acoustic cloak with an effective anisotropic density and an electromagnetic cloak with an effective anisotropic permittivity, respectively. Measured forward scattering for pressure and magnetic fields are in good agreement and provide first evidence of broadband cloaking. Microwave experiments and 3D electromagnetic wave simulations further confirm reduced forward and backscattering when a rectangular metallic obstacle is surrounded by the structured cloak for cloaking frequencies between 2.6 and 7.0 GHz. This suggests, as supported by 2D finite element simulations, sound waves are cloaked between 3 and 8 KHz and linear surface liquid waves between 5 and 16 Hz. Moreover, microwave experiments show the field is reduced by 10 to 30 dB inside the invisibility region, which suggests the multi-wave cloak could be used as a protection against water, sonic or microwaves. © 2015, Nature Publishing Group. All rights reserved.

  14. Static Magnetic Cloak without a Superconductor

    Science.gov (United States)

    Jiang, Wei; Ma, Yungui; He, Sailing

    2018-05-01

    Similar to its electromagnetic counterpart, magnetic cloaking also has very important technological applications. However, the traditional method to build a static magnetic cloak requires the use of superconducting materials as the diamagnetic component, which seriously limits the practical potential because of the cryogenic condition. We show that a diamagnetic active current boundary combined with a high-permeability magnetic inner shell (MIS) can be designed to solve this problem, rendering an ideal magnetic cloaking effect at zero frequency. We first theoretically prove that a current boundary could magnetically behave as a superconductor to external observers. Based on this phenomena, we introduce a high-permeability MIS made of magnetically ultrasoft metallic sheets (permeability μ >103 ) and experimentally prove that the bilayer combination can exactly balance out the disturbance to the external probing field and, meanwhile, have a large invisible inner space. We also show that the active boundary currents can be accordingly configured to overcome the permeability and frequency band limits, leading to a robust cloak over the entire quasistatic frequency region. Our work creates an efficient way to circumvent the traditional limits of metamaterials to build magnetic cloaks for ultralow frequencies. The active-passive hybrid approach could be generally extended to yield other artificial magnetic devices or systems as well.

  15. Unconventional thermal cloak hiding an object outside the cloak

    Science.gov (United States)

    Gao, Y.; Huang, J. P.

    2013-11-01

    All the thermal cloaks reported in the literature can be used to thermally hide an object inside the cloak. However, a common limitation of this kind of thermal cloaks is that the cloaked object cannot feel the external heat flow since it is located inside the cloak; thus we call these cloaks “conventional thermal cloaks”. Here we manage to overcome this limitation by exploiting a class of unconventional thermal cloaks that enable the cloaked object to feel the external heat flow. Our finite-element simulations in two dimensions show the desired cloaking effect. The underlying mechanism originates from the complementary effect of thermal metamaterials with negative thermal conductivities. This work suggests a different method to design thermal devices where heat conduction can be controlled at will.

  16. Designing the coordinate transformation function for non-magnetic invisibility cloaking

    International Nuclear Information System (INIS)

    Xu Xiaofei; Feng Yijun; Zhao Lin; Jiang Tian; Lu Chunhua; Xu Zhongzi

    2008-01-01

    An optical invisibility cloak based on a transformation approach has recently been proposed by a reduced set of material properties due to their easier implementation in reality and little need for an inhomogeneous permeability distribution, but the drawback of undesired scattering caused by the impedance mismatching at the outer boundary is unavoidable in such a cloak. By properly designing the coordinate transformation function to ensure impedance matching at the outer surface, we show that the performance of a nonmagnetic cylindrical cloak could be improved with minimized scattering fields. Using either a single high order power function or an optimized piecewise continuous power function, a cylindrical non-magnetic cloak has been designed with nearly perfect cloaking performance, which is better than those generated with a linear or a quadratic function. Due to the monotonicity of the designed power functions, the resulting cloak has no restriction on the size of the cloaking shell, therefore is suitable for both thick and thin cloaking structures.

  17. Dispersive finite-difference time-domain (FDTD) analysis of the elliptic cylindrical cloak

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. Y.; Ahn, D. [University of Seoul, Seoul (Korea, Republic of)

    2012-05-15

    A dispersive full-wave finite-difference time-domain (FDTD) model is used to calculate the performance of elliptic cylindrical cloaking devices. The permittivity and the permeability tensors for the cloaking structure are derived by using an effective medium approach in general relativity. The elliptic cylindrical invisibility devices are found to show imperfect cloaking, and the cloaking performance is found to depend on the polarization of the incident waves, the direction of the propagation of those waves, the semi-focal distances and the loss tangents of the meta-material. When the semifocal distance of the elliptic cylinder decreases, the performance of the cloaking becomes very good, with neither noticeable scatterings nor field penetrations. For a larger semi-focal distance, only the TM wave with a specific propagation direction shows good cloaking performance. Realistic cloaking materials with loss still show a cloak that is working, but attenuated back-scattering waves exist.

  18. Protecting Superconducting HTS-Antennas by Meta-Material Cloaks

    Science.gov (United States)

    2014-04-30

    to the cloak are not quantified. Thus, one can only visually judge the performance of the cloaking ability of the structure. In this project, a...materials composed of only s-shaped resonators,” Phys. Rev. E, vol. 70, p. 057605, Nov 2004. 8, 9 [25] J. Pendry, A. Holden, D. Robbins , and W

  19. Ray-optics cloaking devices for large objects in incoherent natural light

    Science.gov (United States)

    Chen, Hongsheng; Zheng, Bin; Shen, Lian; Wang, Huaping; Zhang, Xianmin; Zheludev, Nikolay I.; Zhang, Baile

    2013-10-01

    A cloak that can hide living creatures from sight is a common feature of mythology but still remains unrealized as a practical device. To preserve the wave phase, the previous cloaking solution proposed by Pendry and colleagues required transformation of the electromagnetic space around the hidden object in such a way that the rays bending around the object inside the cloak region have to travel faster than those passing it by. This difficult phase preservation requirement is the main obstacle for building a broadband polarization-insensitive cloak for large objects. Here we propose a simplified version of Pendry’s cloak by abolishing the requirement for phase preservation, as it is irrelevant for observation using incoherent natural light with human eyes, which are phase and polarization insensitive. This allows for a cloak design on large scales using commonly available materials. We successfully demonstrate the cloaking of living creatures, a cat and a fish, from the eye.

  20. New procedure to design low radar cross section near perfect isotropic and homogeneous triangular carpet cloaks.

    Science.gov (United States)

    Sharifi, Zohreh; Atlasbaf, Zahra

    2016-10-01

    A new design procedure for near perfect triangular carpet cloaks, fabricated based on only isotropic homogeneous materials, is proposed. This procedure enables us to fabricate a cloak with simple metamaterials or even without employing metamaterials. The proposed procedure together with an invasive weed optimization algorithm is used to design carpet cloaks based on quasi-isotropic metamaterial structures, Teflon and AN-73. According to the simulation results, the proposed cloaks have good invisibility properties against radar, especially monostatic radar. The procedure is a new method to derive isotropic and homogeneous parameters from transformation optics formulas so we do not need to use complicated structures to fabricate the carpet cloaks.

  1. Invisibility cloaking without superluminal propagation

    Energy Technology Data Exchange (ETDEWEB)

    Perczel, Janos; Leonhardt, Ulf [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom); Tyc, Tomas, E-mail: jp394@st-andrews.ac.uk, E-mail: tomtyc@physics.muni.cz, E-mail: ulf@st-andrews.ac.uk [Faculty of Science, Kotlarska 2 and Faculty of Informatics, Botanicka 68a, Masaryk University, 61137 Brno (Czech Republic)

    2011-08-15

    Conventional cloaking based on Euclidean transformation optics requires that the speed of light should tend to infinity on the inner surface of the cloak. Non-Euclidean cloaking still needs media with superluminal propagation. Here we show by giving an example that this is no longer necessary.

  2. Acoustic carpet invisibility cloak with two open windows using multilayered homogeneous isotropic material

    International Nuclear Information System (INIS)

    Ren Chun-Yu; Xiang Zhi-Hai; Cen Zhang-Zhi

    2011-01-01

    We present a method for designing an open acoustic cloak that can conceal a perturbation on flat ground and simultaneously meet the requirement of communication and matter interchange between the inside and the outside of the cloak. This cloak can be constructed with a multilayered structure and each layer is an isotropic and homogeneous medium. The design scheme consists of two steps: firstly, we apply a conformal coordinate transformation to obtain a quasi-perfect cloak with heterogeneous isotropic material; then, according to the profile of the material distribution, we degenerate this cloak into a multilayered-homogeneous isotropic cloak, which has two open windows with negligible disturbance on its invisibility performance. This may greatly facilitate the fabrication and enhance the applicability of such a carpet-type cloak. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  3. Analytical Solution for Elliptical Cloaks Based on The Frequency Selective Surface

    Directory of Open Access Journals (Sweden)

    E. Ghasemi Mizuji

    2015-01-01

    Full Text Available In this paper the elliptical dielectric cylinder which is covered with FSS cloak is considered. Frequency selective surface cloak which Alu named it mantle cloak is one of the recent techniques for cloaking. In this method an appropriate FSS can act as cloaking device for suppressing  the scattering of object  in the desired frequency. With using this method the dimension of the cloaks is extremely reduced. By this proposed structure, the RCS of elliptical cylinder  is reduced about 10-20 dB and designed cloak has an appropriate performance.  The analytical solution for the wave in each layer is presented and with using simulation, the electric field and the scattering pattern has been drawn.

  4. Cloaks with multiple invisible regions

    International Nuclear Information System (INIS)

    Luo, Yang; Zhu, Shouzheng; He, Lianxing; Wang, Yu

    2011-01-01

    This paper proposes a general method of extending the effective invisible regions for both the shell-like interior cloak and the complementary media exterior cloak, without affecting their original cloaking regions. The proposed method is based on layered spatial mapping instead of the intact mapping. Certain interior or exterior invisible regions can be obtained by properly using a compressed or folded transformation in each space layer. Therefore, the proposal enables the as-designed cloaks to provide multiple invisible regions of different types simultaneously. Thus objects can be hidden in the interior cavity and/or in the exterior space, or even be embedded between the cloaking shells

  5. Add-on unidirectional elastic metamaterial plate cloak

    Science.gov (United States)

    Lee, Min Kyung; Kim, Yoon Young

    2016-02-01

    Metamaterial cloaks control the propagation of waves to make an object invisible or insensible. To manipulate elastic waves in space, a metamaterial cloak is typically embedded in a base system that includes or surrounds a target object. The embedding is undesirable because it structurally weakens or permanently alters the base system. In this study, we propose a new add-on metamaterial elastic cloak that can be placed over and mechanically coupled with a base structure without embedding. We designed an add-on type annular metamaterial plate cloak through conformal mapping, fabricated it and performed cloaking experiments in a thin-plate with a hole. Experiments were performed in a thin plate by using the lowest symmetric Lamb wave centered at 100 kHz. As a means to check the cloaking performance of the add-on elastic plate cloak, possibly as a temporary stress reliever or a so-called “stress bandage”, the degree of stress concentration mitigation and the recovery from the perturbed wave field due to a hole were investigated.

  6. Enhanced Near-cloak by FSH Lining

    OpenAIRE

    Liu, Hongyu; Sun, Hongpeng

    2011-01-01

    We consider regularized approximate cloaking for the Helmholtz equation. Various cloaking schemes have been recently proposed and extensively investigated. The existing cloaking schemes in literature are (optimally) within $|\\ln\\rho|^{-1}$ in 2D and $\\rho$ in 3D of the perfect cloaking, where $\\rho$ denotes the regularization parameter. In this work, we develop a cloaking scheme with a well-designed lossy layer right outside the cloaked region that can produce significantly enhanced near-cloa...

  7. Acoustic cloaking in two dimensions: a feasible approach

    Energy Technology Data Exchange (ETDEWEB)

    Torrent, Daniel; Sanchez-Dehesa, Jose [Wave Phenomena Group, Department of Electronic Engineering, Polytechnic University of Valencia, C/ Camino de vera s.n., E-46022 Valencia (Spain)], E-mail: jsdehesa@upvnet.upv.es

    2008-06-15

    This work proposes an acoustic structure feasible to engineer that accomplishes the requirements of acoustic cloaking design recently introduced by Cummer and Schurig (2007 New J. Phys. 9 45). The structure, which consists of a multilayered composite made of two types of isotropic acoustic metamaterials, exactly matches the conditions for the acoustic cloaking. It is also shown that the isotropic metamaterials needed can be made of sonic crystals containing two types of material cylinders, whose elastic parameters should be properly chosen in order to satisfy (in the homogenization limit) the acoustic properties under request. In contrast to electromagnetic cloaking, the structure here proposed verifies the acoustic cloaking in a wide range of wavelengths; its performance is guaranteed for any wavelength above a certain cutoff defined by the homogenization limit of the sonic crystal employed in its fabrication.

  8. A hybrid Scatter/Transform cloaking model

    Directory of Open Access Journals (Sweden)

    Gad Licht

    2015-01-01

    Full Text Available A new Scatter/Transform cloak is developed that combines the light bending of refraction characteristic of a Transform cloak with the scatter cancellation characteristic of a Scatter cloak. The hybrid cloak incorporates both Transform’s variable index of refraction with modified linear intrusions to maximize the Scatter cloak effect. Scatter/Transform improved the scattering cross-section of cloaking in a 2-dimensional space to 51.7% compared to only 39.6% or 45.1% respectively with either Scatter or Transform alone. Metamaterials developed with characteristics based on the new ST hybrid cloak will exhibit superior cloaking capabilities.

  9. Grating-Coupled Waveguide Cloaking

    International Nuclear Information System (INIS)

    Wang Jia-Fu; Qu Shao-Bo; Ma Hua; Wang Cong-Min; Wang Xin-Hua; Zhou Hang; Xu Zhuo; Xia Song

    2012-01-01

    Based on the concept of a grating-coupled waveguide (GCW), a new strategy for realizing EM cloaking is presented. Using metallic grating, incident waves are firstly coupled into the effective waveguide and then decoupled into free space behind, enabling EM waves to pass around the obstacle. Phase compensation in the waveguide keeps the wave-front shape behind the obstacle unchanged. Circular, rectangular and triangular cloaks are presented to verify the robustness of the GCW cloaking. Electric field animations and radar cross section (RCS) comparisons convincingly demonstrate the cloaking effect

  10. Adaptive building skin structures

    International Nuclear Information System (INIS)

    Del Grosso, A E; Basso, P

    2010-01-01

    The concept of adaptive and morphing structures has gained considerable attention in the recent years in many fields of engineering. In civil engineering very few practical applications are reported to date however. Non-conventional structural concepts like deployable, inflatable and morphing structures may indeed provide innovative solutions to some of the problems that the construction industry is being called to face. To give some examples, searches for low-energy consumption or even energy-harvesting green buildings are amongst such problems. This paper first presents a review of the above problems and technologies, which shows how the solution to these problems requires a multidisciplinary approach, involving the integration of architectural and engineering disciplines. The discussion continues with the presentation of a possible application of two adaptive and dynamically morphing structures which are proposed for the realization of an acoustic envelope. The core of the two applications is the use of a novel optimization process which leads the search for optimal solutions by means of an evolutionary technique while the compatibility of the resulting configurations of the adaptive envelope is ensured by the virtual force density method

  11. The Structure of Affine Buildings

    CERN Document Server

    Weiss, Richard M

    2009-01-01

    In The Structure of Affine Buildings, Richard Weiss gives a detailed presentation of the complete proof of the classification of Bruhat-Tits buildings first completed by Jacques Tits in 1986. The book includes numerous results about automorphisms, completions, and residues of these buildings. It also includes tables correlating the results in the locally finite case with the results of Tits's classification of absolutely simple algebraic groups defined over a local field. A companion to Weiss's The Structure of Spherical Buildings, The Structure of Affine Buildings is organized around the clas

  12. EDITORIAL: Focus on Cloaking and Transformation Optics

    Science.gov (United States)

    Leonhardt, Ulf; Smith, David R.

    2008-11-01

    'Any sufficiently advanced technology is indistinguishable from magic', as the late Arthur C Clarke wrote. So what does it take to do magic by technology? Transformation optics has developed some tantalizing ideas and the first practical demonstrations of 'pure and applied magic'. Transformation optics gathers an unusual mix of scientists, ranging from practically-minded engineers to imaginative theoretical physicists and mathematicians or hybrids of all three. The engineers have been developing new materials with extraordinary electromagnetic properties, from materials for microwaves, to be used in radar or wireless technology, to materials for terahertz radiation and visible light. These materials typically are composites—they consist of artificial structures much smaller than the wavelength that act like man-made atoms, apart being much larger in size. The properties of these artificial atoms depend on their shapes and sizes and so they are tunable, in contrast to most real atoms or molecules. This degree of control is what makes these materials—called metamaterials—so interesting. Such new-won freedom invites the other side of the spectrum of scientists, the theorists, to dream. Just imagine there are no practical limits on electromagnetic materials—what could we do with them? One exciting application of metamaterials has been Veselago's idea of negative refraction, dating back to the 1960s. Metamaterials have breathed life into Veselago's idea, culminating in recent optical demonstrations (see for example [1,2]). Another application is cloaking, developing ideas and first experimental demonstrations for invisibility devices [3]. It turns out that both negative refraction and cloaking are examples where materials seem to transform the geometry of space. Any optical material appears to change light's perception of space, as countless optical illusions prove, but the materials of transformation optics act in more specific ways: they appear to perform

  13. Temperature controlled infrared broadband cloaking with the bilayer coatings of semiconductor and superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaohua [College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); College of Physics and Electronics, Yancheng Teachers University, Yancheng 224051 (China); Liu, Youwen, E-mail: ywliu@nuaa.edu.cn [College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Feng, Yuncai [College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

    2015-06-15

    Highlights: • We first propose that the cloak is composed of the bilayer of semiconductor and superconductor. • We realize the infrared broadband cloaking based on the scattering cancellation method. • The cloaking frequency can be tuned by external temperature. - Abstract: The infrared broadband tunable cloaking have been proposed and investigated with the bilayer coating materials of semiconductor (n-Ge) and high-temperature superconductor (YBa{sub 2}Cu{sub 3}O{sub 7}), whose cloaking frequency can be controlled by external temperature. The analytical solution is derived based on the scattering cancellation cloaking technique from the Mie scattering theory, and the full-wave numerical simulation is performed by the finite element method. The calculated and simulated results have demonstrated that this invisibility cloak may reduce the total scattering cross section of the composite structure of 90% over a broad frequency band of nearly 20 THz, and the infrared cloaking frequency can be tuned by the external temperature. It can provide a feasible way to design a broadband tunable cloak.

  14. Analysis of flexural wave cloaks

    Directory of Open Access Journals (Sweden)

    Alfonso Climente

    2016-12-01

    Full Text Available This work presents a comprehensive study of the cloak for bending waves theoretically proposed by Farhat et al. [see Phys. Rev. Lett. 103, 024301 (2009] and later on experimentally realized by Stenger et al. [see Phys. Rev. Lett. 108, 014301 (2012]. This study uses a semi-analytical approach, the multilayer scattering method, which is based in the Kirchoff-Love wave equation for flexural waves in thin plates. Our approach was unable to reproduce the predicted behavior of the theoretically proposed cloak. This disagreement is here explained in terms of the simplified wave equation employed in the cloak design, which employed unusual boundary conditions for the cloaking shell. However, our approach reproduces fairly well the measured displacement maps for the fabricated cloak, indicating the validity of our approach. Also, the cloak quality has been here analyzed using the so called averaged visibility and the scattering cross section. The results obtained from both analysis let us to conclude that there is room for further improvements of this type of flexural wave cloak by using better design procedures.

  15. Structural building screening and evaluation

    Science.gov (United States)

    Kurniawandy, Alex; Nakazawa, Shoji; Hendry, Andy; Ridwan, Firdaus, Rahmatul

    2017-10-01

    An earthquake is a disaster that can be harmful to the community, such as financial loss and also dead injuries. Pekanbaru is a city that located in the middle of Sumatera Island. Even though the city of Pekanbaru is a city that rarely occurs earthquake, but Pekanbaru has ever felt the impact of the big earthquake that occurred in West Sumatera on September 2009. As we know, Indonesia located between Eurasia plate, Pacific plate, and Indo-Australian plate. Particularly the Sumatera Island, It has the Semangko fault or the great Sumatra fault along the island from north to south due to the shift of Eurasia and Indo-Australian Plates. An earthquake is not killing people but the building around the people that could be killing them. The failure of the building can be early prevented by doing an evaluation. In this research, the methods of evaluation have used a guideline for the Federal Emergency Management Agency (FEMA) P-154 and Applied Technology Council (ATC) 40. FEMA P-154 is a rapid visual screening of buildings for potential seismic hazards and ATC-40 is seismic evaluation and retrofit of Concrete Buildings. ATC-40 is a more complex evaluation rather than FEMA P-154. The samples to be evaluated are taken in the surroundings of Universitas Riau facility in Pekanbaru. There are four buildings as case study such as the rent student building, the building of mathematics and natural science faculty, the building teacher training and education faculty and the buildings in the faculty of Social political sciences. Vulnerability for every building facing an earthquake is different, this is depending on structural and non-structural components of the building. Among all of the samples, only the building of mathematics and the natural science faculty is in critical condition according to the FEMA P-154 evaluation. Furthermore, the results of evaluation using ATC-40 for the teacher training building are in damage control conditions, despite the other three buildings are

  16. Structural building response review

    International Nuclear Information System (INIS)

    1980-01-01

    The integrity of a nuclear power plant during a postulated seismic event is required to protect the public against radiation. Therefore, a detailed set of seismic analyses of various structures and equipment is performed while designing a nuclear power plant. This report describes the structural response analysis method, including the structural model, soil-structure interaction as it relates to structural models, methods for seismic structural analysis, numerical integration methods, methods for non-seismic response analysis approaches for various response combinations, structural damping values, nonlinear response, uncertainties in structural properties, and structural response analysis using random properties. The report describes the state-of-the-art in these areas for nuclear power plants. It also details the past studies made at Sargent and Lundy to evaluate different alternatives and the conclusions reached for the specific purposes that those studies were intended. These results were incorporated here because they fall into the general scope of this report. The scope of the present task does not include performing new calculations

  17. Structural rehabilitation of old buildings

    CERN Document Server

    Guedes, João; Varum, Humberto

    2014-01-01

    The present book describes the different construction systems and structural materials and solutions within the main old buildings typologies, and it analyses the particularities of each of them, including mechanical properties, structural behaviour, typical damage patterns and collapse mechanisms. Common or pioneering intervention measures to repair and/or strengthen some of these structural elements are also reviewed.

  18. Invisibility Cloaking Based on Geometrical Optics for Visible Light

    Science.gov (United States)

    Ichikawa, H.; Oura, M.; Taoda, T.

    2013-06-01

    Optical cloaking has been one of unattainable dreams and just a subject in fiction until recently. Several different approaches to cloaking have been proposed and demonstrated: stealth technology, active camouflage and transformation optics. The last one would be the most formal approach modifying electromagnetic field around an object to be cloaked with metamaterials. While cloaking based on transformation optics, though valid only at single frequency, is experimentally demonstrated in microwave region, its operation in visible spectrum is still distant from realisation mainly owing to difficulty in fabricating metamaterial structure whose elements are much smaller than wavelength of light. Here we show that achromatic optical cloaking in visible spectrum is possible with the mere principle based on geometrical optics. In combining a pair of polarising beam splitters and right-angled prisms, rays of light to be obstructed by an object can make a detour to an observer, while unobstructed rays go straight through two polarising beam splitters. What is observed eventually through the device is simply background image as if nothing exists in between.

  19. Size validity of plasma-metamaterial cloaking monitored by scattering wave in finite-difference time-domain method

    Directory of Open Access Journals (Sweden)

    Alexandre Bambina

    2018-01-01

    Full Text Available Limitation of the cloak-size reduction is investigated numerically by a finite-difference time-domain (FDTD method. A metallic pole that imitates an antenna is cloaked with an anisotropic and parameter-gradient medium against electromagnetic-wave propagation in microwave range. The cloaking structure is a metamaterial submerged in a plasma confined in a vacuum chamber made of glass. The smooth-permittivity plasma can be compressed in the radial direction, which enables us to decrease the size of the cloak. Theoretical analysis is performed numerically by comparing scattering waves in various cases; there exists a high reduction of the scattering wave when the radius of the cloak is larger than a quarter of one wavelength. This result indicates that the required size of the cloaking layer is more than an object scale in the Rayleigh scattering regime.

  20. Invisibility and Cloaking: Origins, Present, and Future Perspectives

    Science.gov (United States)

    Fleury, Romain; Monticone, Francesco; Alù, Andrea

    2015-09-01

    The development of metamaterials, i.e., artificially structured materials that interact with waves in unconventional ways, has revolutionized our ability to manipulate the propagation of electromagnetic waves and their interaction with matter. One of the most exciting applications of metamaterial science is related to the possibility of totally suppressing the scattering of an object using an invisibility cloak. Here, we review the available methods to make an object undetectable to electromagnetic waves, and we highlight the outstanding challenges that need to be addressed in order to obtain a fully functional coating capable of suppressing the total scattering of an object. Our outlook discusses how, while passive linear cloaks are fundamentally limited in terms of bandwidth of operation and overall scattering suppression, active and/or nonlinear cloaks hold the promise to overcome, at least partially, some of these limitations.

  1. Metasurface Cloaks for Large Cylindrical Cluster Configurations

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Yakovlev, A.B.

    2014-01-01

    Here, we investigate the performance of metasurfaces used for cloaking of cluster configurations formed by different arrangements of multiple dielectric cylinders and excited by an electric line source. While a suitably designed metasurface can be used to effectively cloak isolated electrically...... small cylinders, we demonstrate that even electrically large clusters of such particles can be cloaked by covering its constituent cylinders with the metasurface cloaks. This holds for densely packed cylinders due to significantly reduced coupling by the presence of the cloaks. The results may...

  2. Lossless acoustic half-bipolar cylindrical cloak with negative-index metamaterial

    Science.gov (United States)

    Lee, Yong Y.; Ahn, Doyeol

    2018-05-01

    A lossless acoustic half-bipolar cylindrical cloak that has an exposed bottom is considered. Here, we show that a cloak that includes a complementary region including a negative-index medium inside of the cloaking shell works in the illumination direction independently even in the presence of the exposed bottom of the structure. This is due to the fact that the phase velocity of the wave in the normal direction can be cancelled in the presence of a boundary containing a negative-index medium that reduces scattering significantly.

  3. Detecting electromagnetic cloaks using backward-propagating waves

    KAUST Repository

    Salem, Mohamed

    2011-08-01

    A novel approach for detecting transformation-optics invisibility cloaks is proposed. The detection method takes advantage of the unusual backward-propagation characteristics of recently reported beams and pulses to induce electromagnetic scattering from the cloak. Even though waves with backward-propagating energy flux cannot penetrate the cloaking shell and interact with the cloaked objects (i.e., they do not make the cloaked object visible), they provide a mechanism for detecting the presence of cloaks. © 2011 IEEE.

  4. Detecting electromagnetic cloaks using backward-propagating waves

    KAUST Repository

    Salem, Mohamed; Bagci, Hakan

    2011-01-01

    A novel approach for detecting transformation-optics invisibility cloaks is proposed. The detection method takes advantage of the unusual backward-propagation characteristics of recently reported beams and pulses to induce electromagnetic scattering from the cloak. Even though waves with backward-propagating energy flux cannot penetrate the cloaking shell and interact with the cloaked objects (i.e., they do not make the cloaked object visible), they provide a mechanism for detecting the presence of cloaks. © 2011 IEEE.

  5. Acoustic cloak/anti-cloak device with realizable passive/active metamaterials

    International Nuclear Information System (INIS)

    Shen Huijie; Wen Jihong; Yu Dianlong; Cai Li; Wen Xisen; Païdoussis, Michael P.

    2012-01-01

    Utilizing the coordinate transformation method, together with exchange of variables between Maxwell's equations and the acoustic equations with axial-invariance in cylindrical coordinates, the acoustic parameters (anisotropic density and scalar bulk modulus) for an ideal cloak and an ideal anti-cloak are obtained. An anti-cloak allows the inside object to ‘see’ outside, but to be invisible from outside; whereas a cloak is invisible from outside, but ‘blind’ from inside. Utilizing a scattering algorithm developed in this paper, the pressure field calculation of the cloak/anti-cloak is performed and the concepts and characteristics of the acoustic cloak/anti-cloak are revisited. To be more easily achievable experimentally, a multilayered cloak/anti-cloak model with homogeneous isotropic materials is introduced, and its corresponding pressure distributions are calculated. Also, the total scattering cross-section curves for the multilayered cloak and anti-cloak over a certain frequency range are presented and compared. Finally, an active acoustic metamaterial made up of piezo-diaphragm cavity arrays is designed for the cloak/anti-cloak. Taking into account the coupling between adjacent cavity cells, a multi-control strategy for piezo-diaphragm cavity arrays is exploited, rendering possible wide ranges of effective densities and effective bulk moduli (or acoustic speeds), or even double-negative transformation medium (i.e. both density and bulk modulus parameters are negative). With such sets of active acoustic metamaterials, the cloak and anti-cloak may become both theoretically and experimentally realizable. (paper)

  6. Electromagnetic Detection of a Perfect Carpet Cloak

    Science.gov (United States)

    Shi, Xihang; Gao, Fei; Lin, Xiao; Zhang, Baile

    2015-05-01

    It has been shown that a spherical invisibility cloak originally proposed by Pendry et al. can be electromagnetically detected by shooting a charged particle through it, whose underlying mechanism stems from the asymmetry of transformation optics applied to motions of photons and charges [PRL 103, 243901 (2009)]. However, the conceptual three-dimensional invisibility cloak that exactly follows specifications of transformation optics is formidably difficult to implement, while the simplified cylindrical cloak that has been experimentally realized is inherently visible. On the other hand, the recent carpet cloak model has acquired remarkable experimental development, including a recently demonstrated full-parameter carpet cloak without any approximation in the required constitutive parameters. In this paper, we numerically investigate the electromagnetic radiation from a charged particle passing through a perfect carpet cloak and propose an experimentally verifiable model to demonstrate symmetry breaking of transformation optics.

  7. A spacetime cloak, or a history editor

    Science.gov (United States)

    McCall, Martin W.; Favaro, Alberto; Kinsler, Paul; Boardman, Allan

    2011-02-01

    We introduce a new type of electromagnetic cloak, the spacetime cloak (STC), which conceals events rather than objects. Non-emitting events occurring during a restricted period are never suspected by a distant observer. The cloak works by locally manipulating the speed of light of an initially uniform light distribution, whilst the light rays themselves always follow straight paths. Any 'perfect' spacetime cloak would necessarily rely upon the technology of electromagnetic metamaterials, which has already been shown to be capable of deforming light in ways hitherto unforeseen—to produce, for example, an electromagnetic object cloak. Nevertheless, we show how it is possible to use intensity-dependent refractive indices to construct an approximate STC, an implementation that would enable the distinct signature of successful event cloaking to be observed. Potential demonstrations include systems that apparently violate quantum statistics, 'interrupt-without-interrupt' computation on convergent data channels and the illusion of a Star Trek transporter.

  8. A spacetime cloak, or a history editor

    International Nuclear Information System (INIS)

    McCall, Martin W; Favaro, Alberto; Kinsler, Paul; Boardman, Allan

    2011-01-01

    We introduce a new type of electromagnetic cloak, the spacetime cloak (STC), which conceals events rather than objects. Non-emitting events occurring during a restricted period are never suspected by a distant observer. The cloak works by locally manipulating the speed of light of an initially uniform light distribution, whilst the light rays themselves always follow straight paths. Any 'perfect' spacetime cloak would necessarily rely upon the technology of electromagnetic metamaterials, which has already been shown to be capable of deforming light in ways hitherto unforeseen—to produce, for example, an electromagnetic object cloak. Nevertheless, we show how it is possible to use intensity-dependent refractive indices to construct an approximate STC, an implementation that would enable the distinct signature of successful event cloaking to be observed. Potential demonstrations include systems that apparently violate quantum statistics, 'interrupt-without-interrupt' computation on convergent data channels and the illusion of a Star Trek transporter

  9. All-dielectric invisibility cloaks made of BaTiO3-loaded polyurethane foam

    International Nuclear Information System (INIS)

    Bao Di; Rajab, Khalid Z; Hao Yang; Kallos, Efthymios; Tang, Wenxuan; Argyropoulos, Christos; Piao Yongzhe; Yang Shoufeng

    2011-01-01

    Transformation optics has led the way in the development of electromagnetic invisibility cloaks from science fiction to engineering practice. Invisibility cloaks have been demonstrated over a wide range of the electromagnetic spectrum, and with a variety of different fabrication techniques. However, all previous schemes have relied on the use of metamaterials consisting of arrays of sub-wavelength inclusions. We report on the first cloaking structure made of a high-κ dielectric-loaded foam mixture. A polyurethane foam mixed with different ratios of barium titanate is used to produce the required range of permittivities, and the invisibility cloak is demonstrated to work for all incident angles over a wide range of microwave frequencies. This method will greatly facilitate the development and large-scale manufacture of a wide range of transformation optics-based structures. (paper)

  10. A multidirectional cloak for visible light

    Science.gov (United States)

    Chen, Zhen Sheng; Lei Mei, Zhong; Jiang, Wei Xiang; Cui, Tie Jun

    2018-04-01

    A new macroscopic multidirectional cloak scheme for extraordinary rays is proposed by controlling the optical axes of uniaxial crystals. It eliminates the complicated material constraints and can also be utilized to design a cloaking device for ordinary rays or isotropic cloaks after simplification. Numerical ray tracing and full-wave simulation results validate our design. Moreover, if the uniaxial crystals are changed into other materials whose optical axes can be modulated, like liquid crystals, this scheme has the potential to fabricate direction-tunable cloaks.

  11. Acoustic cloaking and transformation acoustics

    International Nuclear Information System (INIS)

    Chen Huanyang; Chan, C T

    2010-01-01

    In this review, we give a brief introduction to the application of the new technique of transformation acoustics, which draws on a correspondence between coordinate transformation and material properties. The technique is formulated for both acoustic waves and linear liquid surface waves. Some interesting conceptual devices can be designed for manipulating acoustic waves. For example, we can design acoustic cloaks that make an object invisible to acoustic waves, and the cloak can either encompass or lie outside the object to be concealed. Transformation acoustics, as an analog of transformation optics, can go beyond invisibility cloaking. As an illustration for manipulating linear liquid surface waves, we show that a liquid wave rotator can be designed and fabricated to rotate the wave front. The acoustic transformation media require acoustic materials which are anisotropic and inhomogeneous. Such materials are difficult to find in nature. However, composite materials with embedded sub-wavelength resonators can in principle be made and such 'acoustic metamaterials' can exhibit nearly arbitrary values of effective density and modulus tensors to satisfy the demanding material requirements in transformation acoustics. We introduce resonant sonic materials and Helmholtz resonators as examples of acoustic metamaterials that exhibit resonant behaviour in effective density and effective modulus. (topical review)

  12. Experimental demonstration of invisible electromagnetic impedance matching cylindrical transformation optics cloak shell

    Science.gov (United States)

    Chen, Mingji; Wang, Changxian; Cheng, Xiaodong; Gong, Congcheng; Song, Weili; Yuan, Xujin; Fang, Daining

    2018-04-01

    The realization of an ideal invisible cloak implementing transformation optics is still missing. An impedance matching concept is implanted into transformation optics cloak to generate an impedance matching cloak (IMC) shell. In this work, it is proved that impedance matching structure reduces the cloaking structure’s disturbance to a propagating electromagnetic field and improves its invisibility measured by scattering field intensity. Such a cylindrical IMC shell is designed, fabricated with proposed rounded rectangular split-ring-resonators (RR-SRRs), and experimental measurements show the total scattering field of a perfect electric conductor (PEC) cylinder surrounded by an IMC shell is improved greatly compared to the PEC cylinder showing electromagnetic wave front ripple suppression and a considerable scattering shrinking effect. IMC shell backward scattering field is suppressed down to 7.29%, compared to the previous value of 86.7% due to its impedance matching character, and overall scattering field intensity shrinking is down to 19.3% compared to the previously realized value of 56.4%. Sideward scattering field recorded in the experiment also has a remarkable improvement compared to the PEC cylinder. The impedance matching concept might enlighten the realization of an ideal cloak and other novel electromagnetic cloaking and shielding structures.

  13. Arbitrarily elliptical-cylindrical invisible cloaking

    International Nuclear Information System (INIS)

    Jiang Weixiang; Cui Tiejun; Yu Guanxia; Lin Xianqi; Cheng Qiang; Chin, J Y

    2008-01-01

    Based on the idea of coordinate transformation (Pendry, Schurig and Smith 2006 Science 312 1780), arbitrarily elliptical-cylindrical cloaks are proposed and designed. The elliptical cloak, which is composed of inhomogeneous anisotropic metamaterials in an elliptical-shell region, will deflect incoming electromagnetic (EM) waves and guide them to propagate around the inner elliptical region. Such EM waves will return to their original propagation directions without distorting the waves outside the elliptical cloak. General formulations of the inhomogeneous and anisotropic permittivity and permeability tensors are derived for arbitrarily elliptical axis ratio k, which can also be used for the circular cloak when k = 1. Hence the elliptical cloaks can make a large range of objects invisible, from round objects (when k approaches 1) to long and thin objects (when k is either very large or very small). We also show that the material parameters in elliptical cloaking are singular at only two points, instead of on the whole inner circle for circular cloaking, which are much easier to be realized in actual applications. Full-wave simulations are given to validate the arbitrarily elliptical cloaking

  14. Minimizing the scattering of a nonmagnetic cloak

    DEFF Research Database (Denmark)

    Zhang, Jingjing; Luo, Yu; Mortensen, Asger

    2010-01-01

    Nonmagnetic cloak offers a feasible way to achieve invisibility at optical frequencies using materials with only electric responses. In this letter, we suggest an approximation of the ideal nonmagnetic cloak and quantitatively study its electromagnetic characteristics using a full-wave scattering...

  15. Topology optimized cloak for airborne sound

    DEFF Research Database (Denmark)

    Andkjær, Jacob Anders; Sigmund, Ole

    2013-01-01

    Directional acoustic cloaks that conceal an aluminum cylinder for airborne sound waves are presented in this paper. Subwavelength cylindrical aluminum inclusions in air constitute the cloak design to aid practical realizations. The positions and radii of the subwavelength cylinders are determined...

  16. Rigorous analysis of non-magnetic cloaks

    DEFF Research Database (Denmark)

    Zhang, Jingjing; Luo, Yu; Mortensen, Asger

    2010-01-01

    Nonmagnetic cloak offers a feasible way to achieve invisibility at optical frequencies using materials with only electric responses. In this letter, we suggest an approximation of the ideal nonmagnetic cloak and quantitatively study its electromagnetic characteristics using a full-wave scattering...... to the surrounding material at the outer boundary. Our analysis also provides the flexibility of reducing the scattering in an arbitrary direction....

  17. Fourier analysis: from cloaking to imaging

    Science.gov (United States)

    Wu, Kedi; Cheng, Qiluan; Wang, Guo Ping

    2016-04-01

    Regarding invisibility cloaks as an optical imaging system, we present a Fourier approach to analytically unify both Pendry cloaks and complementary media-based invisibility cloaks into one kind of cloak. By synthesizing different transfer functions, we can construct different devices to realize a series of interesting functions such as hiding objects (events), creating illusions, and performing perfect imaging. In this article, we give a brief review on recent works of applying Fourier approach to analysis invisibility cloaks and optical imaging through scattering layers. We show that, to construct devices to conceal an object, no constructive materials with extreme properties are required, making most, if not all, of the above functions realizable by using naturally occurring materials. As instances, we experimentally verify a method of directionally hiding distant objects and create illusions by using all-dielectric materials, and further demonstrate a non-invasive method of imaging objects completely hidden by scattering layers.

  18. Fourier analysis: from cloaking to imaging

    International Nuclear Information System (INIS)

    Wu, Kedi; Ping Wang, Guo; Cheng, Qiluan

    2016-01-01

    Regarding invisibility cloaks as an optical imaging system, we present a Fourier approach to analytically unify both Pendry cloaks and complementary media-based invisibility cloaks into one kind of cloak. By synthesizing different transfer functions, we can construct different devices to realize a series of interesting functions such as hiding objects (events), creating illusions, and performing perfect imaging. In this article, we give a brief review on recent works of applying Fourier approach to analysis invisibility cloaks and optical imaging through scattering layers. We show that, to construct devices to conceal an object, no constructive materials with extreme properties are required, making most, if not all, of the above functions realizable by using naturally occurring materials. As instances, we experimentally verify a method of directionally hiding distant objects and create illusions by using all-dielectric materials, and further demonstrate a non-invasive method of imaging objects completely hidden by scattering layers. (review)

  19. Galactic optical cloaking of visible baryonic matter

    Science.gov (United States)

    Smolyaninov, Igor I.

    2018-05-01

    Three-dimensional gravitational cloaking is known to require exotic matter and energy sources, which makes it arguably physically unrealizable. On the other hand, typical astronomical observations are performed using one-dimensional paraxial line of sight geometries. We demonstrate that unidirectional line of sight gravitational cloaking does not require exotic matter, and it may occur in multiple natural astronomical scenarios that involve gravitational lensing. In particular, recently discovered double gravitational lens SDSSJ 0 9 4 6 +1 0 0 6 together with the Milky Way appear to form a natural paraxial cloak. A natural question to ask, then, is how much matter in the Universe may be hidden from view by such natural gravitational cloaks? It is estimated that the total volume hidden from an observer by gravitational cloaking may reach about 1% of the total volume of the visible Universe.

  20. Do Cloaked Objects Really Scatter Less?

    Directory of Open Access Journals (Sweden)

    Francesco Monticone

    2013-10-01

    Full Text Available We discuss the global scattering response of invisibility cloaks over the entire electromagnetic spectrum, from static to very high frequencies. Based on linearity, causality, and energy conservation, we show that the total extinction and scattering, integrated over all wavelengths, of any linear, passive, causal, and nondiamagnetic cloak, necessarily increase compared to the uncloaked case. In light of this general principle, we provide a quantitative measure to compare the global performance of different cloaking techniques and we discuss solutions to minimize the global scattering signature of an object using thin, superconducting shells. Our results provide important physical insights on how invisibility cloaks operate and affect the global scattering of an object, suggesting ways to defeat countermeasures aimed at detecting cloaked objects using short impinging pulses.

  1. ORGANIZATIONAL STRUCTURE FOR RECONSTRUCTION OF BUILDINGS HISTORICAL BUILDING OF ODESSA

    Directory of Open Access Journals (Sweden)

    POSTERNAK I. М.

    2017-05-01

    Full Text Available Summary. Raising of problem. As one of perspective forms of integration various complexes act in town- planning structure. In the course of formation of plans of social and economic development of large cities even more often there is a situation when for increase of efficiency of used resources concentration of efforts is necessary not simply, but also new progressive forms of the organization of building manufacture. Purpose. To offer the organizational structure using in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa 1820 … 1920 years under standards power efficiency and to execute researches engineering architectonics residential buildings of historical building of a city of Odessa. Conclusion. It is offered to create in the city of Odessa "the Corporate scientific and technical complex town-planning power reconstruction "CSTC T-PPR", as innovative organizational structure which uses in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa under standards power efficiency. It is considered engineering architectonics residential buildings of historical building of a city of Odessa, in particular, not looking on diverse buildings of inhabited appointment of Odessa, for them there are defining factors on which probably to make their grouping and at the same time to allocate the general lines inherent to a housing estate as a whole. It is resulted a general characteristic and classification of residential buildings of historical building of a city of Odessa ХІХ beginnings ХХ centuries It is allocated and expanded classification of such buildings of inhabited appointment by duration of residing at them.

  2. ORGANIZATIONAL STRUCTURE FOR BUILDINGS RECONSTRUCTION OF HISTORICAL BUILDING OF ODESSA

    Directory of Open Access Journals (Sweden)

    POSTERNAK I. М.

    2016-12-01

    Full Text Available Formulation of the problem. As one of perspective forms of integration various complexes act in town-planning structure. In the course of formation of plans of social and economic development of large cities even more often there is a situation when for increase of efficiency of used resources concentration of efforts is necessary not simply, but also new progressive forms of the organization of building manufacture. Purpose. To offer the organizational structure using in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa 1820 … 1920 years under standards power efficiency and to execute researches engineering architectonics residential buildings of historical building of a city of Odessa. Conclusion. It is offered to create in the city of Odessa "the Corporate scientific and technical complex town-planning power reconstruction "CSTC T-PPR", as innovative organizational structure which uses in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa under standards power efficiency. It is considered engineering architectonics residential buildings of historical building of a city of Odessa, in particular, not looking on diverse buildings of inhabited appointment of Odessa, for them there are defining factors on which probably to make their grouping and at the same time to allocate the general lines inherent to a housing estate as a whole. It is resulted a general characteristic and classification of residential buildings of historical building of a city of Odessa ХІХ … beginnings ХХ centuries It is allocated and expanded classification of such buildings of inhabited appointment by duration of residing at them.

  3. A Distance Bounding Protocol for Location-Cloaked Applications.

    Science.gov (United States)

    Molina-Martínez, Cristián; Galdames, Patricio; Duran-Faundez, Cristian

    2018-04-26

    Location-based services (LBSs) assume that users are willing to release trustworthy and useful details about their whereabouts. However, many location privacy concerns have arisen. For location privacy protection, several algorithms build a cloaking region to hide a user’s location. However, many applications may not operate adequately on cloaked locations. For example, a traditional distance bounding protocol (DBP)—which is run by two nodes called the prover and the verifier—may conclude an untight and useless distance between these two entities. An LBS (verifier) may use this distance as a metric of usefulness and trustworthiness of the location claimed by the user (prover). However, we show that if a tight distance is desired, traditional DBP can refine a user’s cloaked location and compromise its location privacy. To find a proper balance, we propose a location-privacy-aware DBP protocol. Our solution consists of adding some small delays before submitting any user’s response. We show that several issues arise when a certain delay is chosen, and we propose some solutions. The effectiveness of our techniques in balancing location refinement and utility is demonstrated through simulation.

  4. A Distance Bounding Protocol for Location-Cloaked Applications

    Directory of Open Access Journals (Sweden)

    Cristián Molina-Martínez

    2018-04-01

    Full Text Available Location-based services (LBSs assume that users are willing to release trustworthy and useful details about their whereabouts. However, many location privacy concerns have arisen. For location privacy protection, several algorithms build a cloaking region to hide a user’s location. However, many applications may not operate adequately on cloaked locations. For example, a traditional distance bounding protocol (DBP—which is run by two nodes called the prover and the verifier—may conclude an untight and useless distance between these two entities. An LBS (verifier may use this distance as a metric of usefulness and trustworthiness of the location claimed by the user (prover. However, we show that if a tight distance is desired, traditional DBP can refine a user’s cloaked location and compromise its location privacy. To find a proper balance, we propose a location-privacy-aware DBP protocol. Our solution consists of adding some small delays before submitting any user’s response. We show that several issues arise when a certain delay is chosen, and we propose some solutions. The effectiveness of our techniques in balancing location refinement and utility is demonstrated through simulation.

  5. Electromagnetic Detection of a Perfect Invisibility Cloak

    International Nuclear Information System (INIS)

    Zhang Baile; Wu, Bae-Ian

    2009-01-01

    A perfect invisibility cloak is commonly believed to be undetectable from electromagnetic (EM) detection because it is equivalent to a curved but empty EM space created from coordinate transformation. Based on the intrinsic asymmetry of coordinate transformation applied to motions of photons and charges, we propose a method to detect this curved EM space by shooting a fast-moving charged particle through it. A broadband radiation generated in this process makes a cloak visible. Our method is the only known EM mechanism so far to detect an ideal perfect cloak (curved EM space) within its working band.

  6. Design of invisibility cloaks with an open tunnel.

    Science.gov (United States)

    Ako, Thomas; Yan, Min; Qiu, Min

    2010-12-20

    In this paper we apply the methodology of transformation optics for design of a novel invisibility cloak which can possess an open tunnel. Such a cloak facilitates the insertion (retrieval) of matter into (from) the cloak's interior without significantly affecting the cloak's performance, overcoming the matter exchange bottleneck inherent to most previously proposed cloak designs.We achieve this by applying a transformation which expands a point at the origin in electromagnetic space to a finite area in physical space in a highly anisotropic manner. The invisibility performance of the proposed cloak is verified by using full-wave finite-element simulations.

  7. Isotropic and anisotropic surface wave cloaking techniques

    International Nuclear Information System (INIS)

    McManus, T M; Spada, L La; Hao, Y

    2016-01-01

    In this paper we compare two different approaches for surface waves cloaking. The first technique is a unique application of Fermat’s principle and requires isotropic material properties, but owing to its derivation is limited in its applicability. The second technique utilises a geometrical optics approximation for dealing with rays bound to a two dimensional surface and requires anisotropic material properties, though it can be used to cloak any smooth surface. We analytically derive the surface wave scattering behaviour for both cloak techniques when applied to a rotationally symmetric surface deformation. Furthermore, we simulate both using a commercially available full-wave electromagnetic solver and demonstrate a good level of agreement with their analytically derived solutions. Our analytical solutions and simulations provide a complete and concise overview of two different surface wave cloaking techniques. (paper)

  8. Isotropic and anisotropic surface wave cloaking techniques

    Science.gov (United States)

    McManus, T. M.; La Spada, L.; Hao, Y.

    2016-04-01

    In this paper we compare two different approaches for surface waves cloaking. The first technique is a unique application of Fermat’s principle and requires isotropic material properties, but owing to its derivation is limited in its applicability. The second technique utilises a geometrical optics approximation for dealing with rays bound to a two dimensional surface and requires anisotropic material properties, though it can be used to cloak any smooth surface. We analytically derive the surface wave scattering behaviour for both cloak techniques when applied to a rotationally symmetric surface deformation. Furthermore, we simulate both using a commercially available full-wave electromagnetic solver and demonstrate a good level of agreement with their analytically derived solutions. Our analytical solutions and simulations provide a complete and concise overview of two different surface wave cloaking techniques.

  9. Detailed optical characterization of three-dimensional visible-frequency polarization-independent carpet invisibility cloak

    International Nuclear Information System (INIS)

    Ergin, Tolga; Fischer, Joachim; Wegener, Martin

    2012-01-01

    The invention of the three-dimensional woodpile photonic crystal by Costas M. Soukoulis and coworkers in 1994 has stimulated much further research - excellent research stimulates further research. Here, we report on using spatially inhomogeneous polymer woodpile structures in the long-wavelength limit as artificial graded-index structures. After briefly reviewing previous work on carpet invisibility cloaks designed by transformation optics, we present new experiments for various focus planes of the inspecting microscope as well as for different inspection angles in three-dimensional space. Numerical ray-tracing modeling is also provided. These data confirm our previous assessment that three-dimensional cloaking is quite robust for these structures.

  10. Elliptical metasurfaces for cloaking and antenna applications at microwave and terahertz frequencies

    Science.gov (United States)

    Mehrpourbernety, Hossein

    One of the interesting applications of metamaterials is the phenomenon of electromagnetic invisibility and cloaking, which implies the suppression of bistatic scattering width of a given object, independent of incident and observation angles. In this regard, diverse techniques have been proposed to analyze and design electromagnetic cloak structures, including transformation optics, anomalous resonance methods, transmission-line networks, and plasmonic cloaking, among others. A common drawback of all these methods is that they rely on bulk materials, which are difficult to realize in practice. To overcome this issue, the mantle cloaking method has been proposed, which utilizes an ultrathin metasurface that provides anti-phase surface currents to reduce the scattering dominant mode of a given object. Recently, an analytical model has been proposed to cloak dielectric and conducting cylindrical objects realized with printed and slotted arrays at microwave frequencies. At low-terahertz (THz) frequencies, one of the promising materials to realize the required metasurface is graphene. In this regard, a graphene monolayer, characterized by inductive reactance, has been proposed to cloak dielectric planar and cylindrical objects. Then, it has been shown that a metasurface made of graphene nanopatches owns dual capacitive/inductive inductance and can be used to cloak both dielectric and conducting cylindrical objects at low-THz frequencies. So far, planar and cylindrical dielectric and conducting structures have been studied. In our study, we have extended the concept and presented an accurate analytical approach to investigate the cloaking of two-dimensional (2-D) elliptical objects including infinite dielectric elliptical cylinders using graphene monolayer; metallic elliptical cylinders, and also, as a special case, 2-D metallic strips using a nanostructured graphene patch array at low-THz frequencies. We have also obtained the results for cloaking of ellipses at

  11. An ultrathin invisibility skin cloak for visible light.

    Science.gov (United States)

    Ni, Xingjie; Wong, Zi Jing; Mrejen, Michael; Wang, Yuan; Zhang, Xiang

    2015-09-18

    Metamaterial-based optical cloaks have thus far used volumetric distribution of the material properties to gradually bend light and thereby obscure the cloaked region. Hence, they are bulky and hard to scale up and, more critically, typical carpet cloaks introduce unnecessary phase shifts in the reflected light, making the cloaks detectable. Here, we demonstrate experimentally an ultrathin invisibility skin cloak wrapped over an object. This skin cloak conceals a three-dimensional arbitrarily shaped object by complete restoration of the phase of the reflected light at 730-nanometer wavelength. The skin cloak comprises a metasurface with distributed phase shifts rerouting light and rendering the object invisible. In contrast to bulky cloaks with volumetric index variation, our device is only 80 nanometer (about one-ninth of the wavelength) thick and potentially scalable for hiding macroscopic objects. Copyright © 2015, American Association for the Advancement of Science.

  12. Super-structure and building performance

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-11-01

    Full Text Available The super-structure consists predominantly of the load- and no-load-bearing walls-including all doors and windows and suspended floor slabs. The building envelope plays a significant role in the performance of a building, especially with regard...

  13. Towards all-dielectric, polarization-independent optical cloaks

    DEFF Research Database (Denmark)

    Andkjær, Jacob Anders; Mortensen, N. Asger; Sigmund, Ole

    2012-01-01

    Fully enclosing, all-dielectric cloaks working for both E-z and H-z polarizations simultaneously are presented in this letter. The cloaks are effective for two antiparallel angles of incidence, and the layout of standard dielectric material in the cloak is determined by topology optimization. Sca...... effectively when distributing a material with lower permittivity than the background material....

  14. Structured building model reduction toward parallel simulation

    Energy Technology Data Exchange (ETDEWEB)

    Dobbs, Justin R. [Cornell University; Hencey, Brondon M. [Cornell University

    2013-08-26

    Building energy model reduction exchanges accuracy for improved simulation speed by reducing the number of dynamical equations. Parallel computing aims to improve simulation times without loss of accuracy but is poorly utilized by contemporary simulators and is inherently limited by inter-processor communication. This paper bridges these disparate techniques to implement efficient parallel building thermal simulation. We begin with a survey of three structured reduction approaches that compares their performance to a leading unstructured method. We then use structured model reduction to find thermal clusters in the building energy model and allocate processing resources. Experimental results demonstrate faster simulation and low error without any interprocessor communication.

  15. A new metamaterial-based wideband rectangular invisibility cloak

    Science.gov (United States)

    Islam, S. S.; Hasan, M. M.; Faruque, M. R. I.

    2018-02-01

    A new metamaterial-based wideband electromagnetic rectangular cloak is being introduced in this study. The metamaterial unit cell shows sharp transmittances in the C- and X-bands and displays wideband negative effective permittivity region there. The metamaterial unit cell was then applied in designing a rectangular-shaped electromagnetic cloak. The scattering reduction technique was adopted for the cloaking operation. The cloak operates in the certain portion of C-and X-bands that covers more than 4 GHz bandwidth region. The experimental results were provided as well for the metamaterial and the cloak.

  16. Flow stabilization with active hydrodynamic cloaks.

    Science.gov (United States)

    Urzhumov, Yaroslav A; Smith, David R

    2012-11-01

    We demonstrate that fluid flow cloaking solutions, based on active hydrodynamic metamaterials, exist for two-dimensional flows past a cylinder in a wide range of Reynolds numbers (Re's), up to approximately 200. Within the framework of the classical Brinkman equation for homogenized porous flow, we demonstrate using two different methods that such cloaked flows can be dynamically stable for Re's in the range of 5-119. The first highly efficient method is based on a linearization of the Brinkman-Navier-Stokes equation and finding the eigenfrequencies of the least stable eigenperturbations; the second method is a direct numerical integration in the time domain. We show that, by suppressing the von Kármán vortex street in the weakly turbulent wake, porous flow cloaks can raise the critical Reynolds number up to about 120 or five times greater than for a bare uncloaked cylinder.

  17. Illusions and Cloaks for Surface Waves

    Science.gov (United States)

    McManus, T. M.; Valiente-Kroon, J. A.; Horsley, S. A. R.; Hao, Y.

    2014-08-01

    Ever since the inception of Transformation Optics (TO), new and exciting ideas have been proposed in the field of electromagnetics and the theory has been modified to work in such fields as acoustics and thermodynamics. The most well-known application of this theory is to cloaking, but another equally intriguing application of TO is the idea of an illusion device. Here, we propose a general method to transform electromagnetic waves between two arbitrary surfaces. This allows a flat surface to reproduce the scattering behaviour of a curved surface and vice versa, thereby giving rise to perfect optical illusion and cloaking devices, respectively. The performance of the proposed devices is simulated using thin effective media with engineered material properties. The scattering of the curved surface is shown to be reproduced by its flat analogue (for illusions) and vice versa for cloaks.

  18. Earthquake risk assessment of building structures

    International Nuclear Information System (INIS)

    Ellingwood, Bruce R.

    2001-01-01

    During the past two decades, probabilistic risk analysis tools have been applied to assess the performance of new and existing building structural systems. Structural design and evaluation of buildings and other facilities with regard to their ability to withstand the effects of earthquakes requires special considerations that are not normally a part of such evaluations for other occupancy, service and environmental loads. This paper reviews some of these special considerations, specifically as they pertain to probability-based codified design and reliability-based condition assessment of existing buildings. Difficulties experienced in implementing probability-based limit states design criteria for earthquake are summarized. Comparisons of predicted and observed building damage highlight the limitations of using current deterministic approaches for post-earthquake building condition assessment. The importance of inherent randomness and modeling uncertainty in forecasting building performance is examined through a building fragility assessment of a steel frame with welded connections that was damaged during the Northridge Earthquake of 1994. The prospects for future improvements in earthquake-resistant design procedures based on a more rational probability-based treatment of uncertainty are examined

  19. Design, implementation, and extension of thermal invisibility cloaks

    Science.gov (United States)

    Zhang, Youming; Xu, Hongyi; Zhang, Baile

    2015-05-01

    A thermal invisibility cloak, as inspired by optical invisibility cloaks, is a device which can steer the conductive heat flux around an isolated object without changing the ambient temperature distribution so that the object can be "invisible" to external thermal environment. While designs of thermal invisibility cloaks inherit previous theories from optical cloaks, the uniqueness of heat diffusion leads to more achievable implementations. Thermal invisibility cloaks, as well as the variations including thermal concentrator, rotator, and illusion devices, have potentials to be applied in thermal management, sensing and imaging applications. Here, we review the current knowledge of thermal invisibility cloaks in terms of their design and implementation in cloaking studies, and their extension as other functional devices.

  20. Measurement methods of building structures deflections

    Directory of Open Access Journals (Sweden)

    Wróblewska Magdalena

    2018-01-01

    Full Text Available Underground mining exploitation is leading to the occurrence of deformations manifested by, in particular, sloping terrain. The structures situated on the deforming subsoil are subject to uneven subsidence which is leading in consequence to their deflection. Before a building rectification process takes place by, e.g. uneven raising, the structure's deflection direction and value is determined so that the structure is restored to its vertical position as a result of the undertaken remedial measures. Deflection can be determined by applying classical as well as modern measurement techniques. The article presents examples of measurement methods used considering the measured elements of building structures’ constructions and field measurements. Moreover, for a given example of a mining area, the existing deflections of buildings were compared with mining terrain sloping.

  1. Cloaking and imaging at the same time

    Science.gov (United States)

    Wu, Qiannan; Xu, Yadong; Li, Hui; Chen, Huanyang

    2013-02-01

    In this letter, we propose a conceptual device to perform good imaging with positive refraction. At the same time, this device is an isotropic omnidirectional cloak with a perfect electric conductor hiding region and shows versatile illusion optical effects. Numerical simulations are performed to verify the functionalities.

  2. The fundamentals of structural building codes

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2001-01-01

    Partial Factor Design is nowadays a generally accepted design method for building and civil engineering structures. For most engineers the general philosophy that the safety factors depend on the type of the load and on the limit state under consideration makes sense. However, the background, in

  3. On Directionality of Phrase Structure Building

    Science.gov (United States)

    Chesi, Cristiano

    2015-01-01

    Minimalism in grammatical theorizing (Chomsky in "The minimalist program." MIT Press, Cambridge, 1995) led to simpler linguistic devices and a better focalization of the core properties of the structure building engine: a lexicon and a free (recursive) phrase formation operation, dubbed Merge, are the basic components that serve in…

  4. Decentralized Networked Control of Building Structures

    Czech Academy of Sciences Publication Activity Database

    Bakule, Lubomír; Rehák, Branislav; Papík, Martin

    2016-01-01

    Roč. 31, č. 11 (2016), s. 871-886 ISSN 1093-9687 R&D Projects: GA ČR GA13-02149S Institutional support: RVO:67985556 Keywords : decentralized control * networked control * building structures Subject RIV: BC - Control Systems Theory Impact factor: 5.786, year: 2016

  5. Enhanced approximate cloaking by SH and FSH lining

    International Nuclear Information System (INIS)

    Li, Jingzhi; Liu, Hongyu; Sun, Hongpeng

    2012-01-01

    We consider approximate cloaking from a regularization viewpoint introduced in Kohn et al (2008 Inverse Problems 24 015016) for EIT and further investigated in Kohn et al (2010 Commun. Pure Appl. Math. 63 0973–1016) and Liu (2009 Inverse Problems 25 045006) for the Helmholtz equation. The cloaking schemes given by Kohn et al and Liu are shown to be (optimally) within |ln ρ| −1 in 2D and ρ in 3D of perfect cloaking, where ρ denotes the regularization parameter. In this paper, we show that by employing a sound-hard layer right outside the cloaked region, one could (optimally) achieve ρ N in R N , N ≥ 2, which significantly enhances the near-cloak. We then develop a cloaking scheme by making use of a lossy layer with well-chosen parameters. The lossy-layer cloaking scheme is shown to possess the same cloaking performance as the one with a sound-hard layer. Moreover, it is shown that the lossy layer could be taken as a finite realization of the sound-hard layer. Numerical experiments are also presented to assess the cloaking performances of all the cloaking schemes for comparisons. (paper)

  6. A rigorous analysis of high-order electromagnetic invisibility cloaks

    International Nuclear Information System (INIS)

    Weder, Ricardo

    2008-01-01

    There is currently a great deal of interest in the invisibility cloaks recently proposed by Pendry et al that are based on the transformation approach. They obtained their results using first-order transformations. In recent papers, Hendi et al and Cai et al considered invisibility cloaks with high-order transformations. In this paper, we study high-order electromagnetic invisibility cloaks in transformation media obtained by high-order transformations from general anisotropic media. We consider the case where there is a finite number of spherical cloaks located in different points in space. We prove that for any incident plane wave, at any frequency, the scattered wave is identically zero. We also consider the scattering of finite-energy wave packets. We prove that the scattering matrix is the identity, i.e., that for any incoming wave packet the outgoing wave packet is the same as the incoming one. This proves that the invisibility cloaks cannot be detected in any scattering experiment with electromagnetic waves in high-order transformation media, and in particular in the first-order transformation media of Pendry et al. We also prove that the high-order invisibility cloaks, as well as the first-order ones, cloak passive and active devices. The cloaked objects completely decouple from the exterior. Actually, the cloaking outside is independent of what is inside the cloaked objects. The electromagnetic waves inside the cloaked objects cannot leave the concealed regions and vice versa, the electromagnetic waves outside the cloaked objects cannot go inside the concealed regions. As we prove our results for media that are obtained by transformation from general anisotropic materials, we prove that it is possible to cloak objects inside general crystals

  7. Ultra-broadband carpet cloak for transverse-electric polarization

    International Nuclear Information System (INIS)

    Deng, Ye; Xu, Su; Zhang, Runren; Zheng, Bin; Chen, Hongsheng; Chen, Hua; Yu, Faxin; Gao, Fei; Zhang, Baile

    2016-01-01

    Magnetism is a necessity in constructing macroscopic metamaterial invisibility cloaks that are theoretically designed by transformation optics, but will generally limit the cloaking bandwidth to an impractically narrow range. To meet the broad bandwidth demand, magnetism has been fully abandoned in previous demonstrations of macroscopic carpet cloaking, whose approach, however, cannot apply to a transverse-electric (TE) polarization. To fill this gap, here we experimentally demonstrate an ultra-broadband magnetic carpet cloak for the TE polarization. The cloak is made of non-resonant closed-ring metamaterials with little dispersion and the cloaking performance is confirmed with both time-domain simulation and frequency scanning measurement over a broad bandwidth corresponding to a pulse signal illumination. (paper)

  8. Ultra-broadband carpet cloak for transverse-electric polarization

    Science.gov (United States)

    Deng, Ye; Xu, Su; Zhang, Runren; Zheng, Bin; Chen, Hua; Gao, Fei; Yu, Faxin; Zhang, Baile; Chen, Hongsheng

    2016-04-01

    Magnetism is a necessity in constructing macroscopic metamaterial invisibility cloaks that are theoretically designed by transformation optics, but will generally limit the cloaking bandwidth to an impractically narrow range. To meet the broad bandwidth demand, magnetism has been fully abandoned in previous demonstrations of macroscopic carpet cloaking, whose approach, however, cannot apply to a transverse-electric (TE) polarization. To fill this gap, here we experimentally demonstrate an ultra-broadband magnetic carpet cloak for the TE polarization. The cloak is made of non-resonant closed-ring metamaterials with little dispersion and the cloaking performance is confirmed with both time-domain simulation and frequency scanning measurement over a broad bandwidth corresponding to a pulse signal illumination.

  9. Broadband unidirectional cloaks based on flat metasurface focusing lenses

    International Nuclear Information System (INIS)

    Li, Yongfeng; Zhang, Jieqiu; Qu, Shaobo; Wang, Jiafu; Pang, Yongqiang; Xu, Zhuo; Zhang, Anxue

    2015-01-01

    Bandwidth extension and thickness reduction are now the two key issues of cloaks. In this paper, we propose to achieve broadband, thin uni-directional electromagnetic (EM) cloaks using metasurfaces. To this end, a wideband flat focusing lens is firstly devised based on high-efficiency transmissive metasurfaces. Due to the nearly dispersionless parabolic phase profile along the metasurface in the operating band, incident plane waves can be focused efficiently after passing through the metasurface. Broadband unidirectional EM cloaks were then designed by combining two identical flat lenses. Upon illumination, the incident plane waves are firstly focused by one lens and then are restored by the other lens, avoiding the cloaked region. Both simulation and experiment results verify the broadband unidirectional cloak. The broad bandwidth and small thickness of such cloaks have potential applications in achieving invisibility for electrically large objects. (paper)

  10. Broadband unidirectional cloaks based on flat metasurface focusing lenses

    Science.gov (United States)

    Li, Yongfeng; Zhang, Jieqiu; Qu, Shaobo; Wang, Jiafu; Pang, Yongqiang; Xu, Zhuo; Zhang, Anxue

    2015-08-01

    Bandwidth extension and thickness reduction are now the two key issues of cloaks. In this paper, we propose to achieve broadband, thin uni-directional electromagnetic (EM) cloaks using metasurfaces. To this end, a wideband flat focusing lens is firstly devised based on high-efficiency transmissive metasurfaces. Due to the nearly dispersionless parabolic phase profile along the metasurface in the operating band, incident plane waves can be focused efficiently after passing through the metasurface. Broadband unidirectional EM cloaks were then designed by combining two identical flat lenses. Upon illumination, the incident plane waves are firstly focused by one lens and then are restored by the other lens, avoiding the cloaked region. Both simulation and experiment results verify the broadband unidirectional cloak. The broad bandwidth and small thickness of such cloaks have potential applications in achieving invisibility for electrically large objects.

  11. Nonideal ultrathin mantle cloak for electrically large conducting cylinders.

    Science.gov (United States)

    Liu, Shuo; Zhang, Hao Chi; Xu, He-Xiu; Cui, Tie Jun

    2014-09-01

    Based on the concept of the scattering cancellation technique, we propose a nonideal ultrathin mantle cloak that can efficiently suppress the total scattering cross sections of an electrically large conducting cylinder (over one free-space wavelength). The cloaking mechanism is investigated in depth based on the Mie scattering theory and is simultaneously interpreted from the perspective of far-field bistatic scattering and near-field distributions. We remark that, unlike the perfect transformation-optics-based cloak, this nonideal cloaking technique is mainly designed to minimize simultaneously several scattering multipoles of a relatively large geometry around considerably broad bandwidth. Numerical simulations and experimental results show that the antiscattering ability of the metasurface gives rise to excellent total scattering reduction of the electrically large cylinder and remarkable electric-field restoration around the cloak. The outstanding cloaking performance together with the good features of and ultralow profile, flexibility, and easy fabrication predict promising applications in the microwave frequencies.

  12. Coordinate transformations make perfect invisibility cloaks with arbitrary shape

    International Nuclear Information System (INIS)

    Yan Wei; Yan Min; Ruan Zhichao; Qiu Min

    2008-01-01

    By investigating wave properties at cloak boundaries, invisibility cloaks with arbitrary shape constructed by general coordinate transformations are confirmed to be perfectly invisible to the external incident wave. The differences between line transformed cloaks and point transformed cloaks are discussed. The fields in the cloak medium are found analytically to be related to the fields in the original space via coordinate transformation functions. At the exterior boundary of the cloak, it is shown that no reflection is excited even though the permittivity and permeability do not always have a perfectly matched layer form, whereas at the inner boundary, no reflection is excited either, and in particular no field can penetrate into the cloaked region. However, for the inner boundary of any line transformed cloak, the permittivity and permeability in a specific tangential direction are always required to be infinitely large. Furthermore, the field discontinuity at the inner boundary always exists; the surface current is induced to make this discontinuity self-consistent. A point transformed cloak does not experience such problems. The tangential fields at the inner boundary are all zero, implying that no field discontinuity exists

  13. STRUCTURAL VULNERABILITY ASSESSMENT OF MASONRY BUILDINGS IN TURKEY

    OpenAIRE

    KORKMAZ, Kasım Armagan; CARHOGLU, Asuman Isıl

    2011-01-01

    Turkey is located in an active seismic zone. Mid to high rise R/C building and low rise masonry buildings are very common construction type in Turkey. In recent earthquakes, lots of existing buildings got damage including masonry buildings. Masonry building history in Turkey goes long years back. For sure, it is an important structure type for Turkey. Therefore, earthquake behavior and structural vulnerability of masonry buildings are crucial issues for Turkey as a earthquake prone country. I...

  14. Determining building interior structures using compressive sensing

    Science.gov (United States)

    Lagunas, Eva; Amin, Moeness G.; Ahmad, Fauzia; Nájar, Montse

    2013-04-01

    We consider imaging of the building interior structures using compressive sensing (CS) with applications to through-the-wall imaging and urban sensing. We consider a monostatic synthetic aperture radar imaging system employing stepped frequency waveform. The proposed approach exploits prior information of building construction practices to form an appropriate sparse representation of the building interior layout. We devise a dictionary of possible wall locations, which is consistent with the fact that interior walls are typically parallel or perpendicular to the front wall. The dictionary accounts for the dominant normal angle reflections from exterior and interior walls for the monostatic imaging system. CS is applied to a reduced set of observations to recover the true positions of the walls. Additional information about interior walls can be obtained using a dictionary of possible corner reflectors, which is the response of the junction of two walls. Supporting results based on simulation and laboratory experiments are provided. It is shown that the proposed sparsifying basis outperforms the conventional through-the-wall CS model, the wavelet sparsifying basis, and the block sparse model for building interior layout detection.

  15. On three-dimensional spherical acoustic cloaking

    International Nuclear Information System (INIS)

    Munteanu, Ligia; Chiroiu, Veturia

    2011-01-01

    Transformation acoustics opens a new avenue towards the design of acoustic metamaterials, which are materials engineered at the subwavelength scale in order to mimic the parameters in wave equations. The design of the acoustic cloaking is based on the property of equations being invariant under a coordinate transformation, i.e. a specific spatial compression is equivalent to a variation of the material parameters in the original space. In this paper, the sound invisibility performance is discussed for spherical cloaks. The original domain consists of alternating concentric layers made from piezoelectric ceramics and epoxy resin, following a triadic Cantor sequence. The spatial compression, obtained by applying the concave-down transformation, leads to an equivalent domain with an inhomogeneous and anisotropic distribution of the material parameters.

  16. A cloaking device for transiting planets

    Science.gov (United States)

    Kipping, David M.; Teachey, Alex

    2016-06-01

    The transit method is presently the most successful planet discovery and characterization tool at our disposal. Other advanced civilizations would surely be aware of this technique and appreciate that their home planet's existence and habitability is essentially broadcast to all stars lying along their ecliptic plane. We suggest that advanced civilizations could cloak their presence, or deliberately broadcast it, through controlled laser emission. Such emission could distort the apparent shape of their transit light curves with relatively little energy, due to the collimated beam and relatively infrequent nature of transits. We estimate that humanity could cloak the Earth from Kepler-like broad-band surveys using an optical monochromatic laser array emitting a peak power of ˜30 MW for ˜10 hours per year. A chromatic cloak, effective at all wavelengths, is more challenging requiring a large array of tunable lasers with a total power of ˜250 MW. Alternatively, a civilization could cloak only the atmospheric signatures associated with biological activity on their world, such as oxygen, which is achievable with a peak laser power of just ˜160 kW per transit. Finally, we suggest that the time of transit for optical Search for Extraterrestrial Intelligence (SETI) is analogous to the water-hole in radio SETI, providing a clear window in which observers may expect to communicate. Accordingly, we propose that a civilization may deliberately broadcast their technological capabilities by distorting their transit to an artificial shape, which serves as both a SETI beacon and a medium for data transmission. Such signatures could be readily searched in the archival data of transit surveys.

  17. 7 CFR 51.56 - Buildings and structures.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Buildings and structures. 51.56 Section 51.56... § 51.56 Buildings and structures. The packing plant buildings shall be properly constructed and... be sufficient light consistent with the use to which the particular portion of the building is...

  18. Vibration-damping structure for reactor building

    International Nuclear Information System (INIS)

    Kuno, Toshio; Iba, Chikara; Tanaka, Hideki; Kageyama, Mitsuru

    1998-01-01

    In a damping structure of a reactor building, an inner concrete body and a reactor container are connected by way of a vibration absorbing member. As the vibration absorbing member, springs or dampers are used. The inner concrete body and the reactor container each having weight and inherent frequency different from each other are opposed displaceably by way of the vibration absorbing member thereby enabling to reduce seismic input and reduce shearing force at least at leg portions. Accordingly, seismic loads are reduced to increase the grounding rate of the base thereby enabling to satisfy an allowable value. Therefore, it is not necessary to strengthen the inner concrete body and the reactor container excessively, the amount of reinforcing rods can be reduced, and the amount of a portion of the base buried to the ground can be reduced thereby enabling to constitute the reactor building easily. (N.H.)

  19. The boundary conditions for point transformed electromagnetic invisibility cloaks

    International Nuclear Information System (INIS)

    Weder, Ricardo

    2008-01-01

    In this paper we study point transformed electromagnetic invisibility cloaks in transformation media that are obtained by transformation from general anisotropic media. We assume that there are several point transformed electromagnetic cloaks located in different points in space. Our results apply in particular to the first-order invisibility cloaks introduced by Pendry et al and to the high-order invisibility cloaks introduced by Hendi et al and by Cai et al. We identify the appropriate cloaking boundary conditions that the solutions of Maxwell equations have to satisfy at the outside, ∂K + , and at the inside, ∂K - , of the boundary of the cloaked object K in the case where the permittivity and the permeability are bounded below and above in K. Namely, that the tangential components of the electric and the magnetic fields have to vanish at ∂K + -which is always true-and that the normal components of the curl of the electric and the magnetic fields have to vanish at ∂K - . These results are proven requiring that energy be conserved. In the case of one spherical cloak with a spherically stratified K and a radial current at ∂K we verify by an explicit calculation that our cloaking boundary conditions are satisfied and that cloaking of active devices holds, even if the current is at the boundary of the cloaked object. As we prove our results for media that are obtained by transformation from general anisotropic media, our results apply to the cloaking of objects with passive and active devices contained in general anisotropic media, in particular to objects with passive and active devices contained inside general crystals. Our results suggest a method to enhance cloaking in the approximate transformation media that are used in practice. Namely, to coat the boundary of the cloaked object (the inner boundary of the cloak) with a material that imposes the boundary conditions above. As these boundary conditions have to be satisfied for exact transformation

  20. Revisit the carpet cloak from optical conformal mapping

    OpenAIRE

    Li, Hui; Xu, Yadong; Wu, Qiannan; Chen, Huanyang

    2013-01-01

    The original carpet cloak [Phys. Rev. Lett. 101, 203901 (2008)] was designed by a numerical method, the quasi-conformal mapping. Therefore its refractive index profile was obtained numerically. In this letter, we propose a new carpet cloak based on the optical conformal mapping, with an analytical form of a refractive index profile, thereby facilitating future experimental designs.

  1. Experimental Verification of Plasmonic Cloaking at Microwave Frequencies with Metamaterials

    International Nuclear Information System (INIS)

    Edwards, Brian; Engheta, Nader; Alu, Andrea; Silveirinha, Mario G.

    2009-01-01

    Plasmonic cloaking is a scattering-cancellation technique based on the local negative polarizability of metamaterials. Here we report its first experimental realization and measurement at microwave frequencies. An array of metallic fins embedded in a high-permittivity fluid has been used to create a metamaterial plasmonic shell capable of cloaking a dielectric cylinder, yielding over 75% reduction of total scattering width.

  2. MODERN BUILDING STRUCTURES USED FOR MILITARY PURPOSES

    Directory of Open Access Journals (Sweden)

    Mariana Domnica STANCIU

    2014-04-01

    Full Text Available This paper investigates the technical aspects of the spherical spatial structures, focusing on the tensegrity building systems used for military purpose. The spherical spatial structures have been studied and used since antiquity. Pythagoras, Plato and Euclid were conducted extensive research on the concept of such type of structures. Regular pentagon has properties related to the value of the golden section, intuitively used by great architects and engineers since ancient times. In the Middle Ages, Leonardo Da Vinci created spatial objects using proportions based on the golden number, and later R. B. Fuller made the famous geodesic domes. The structures proposed by the authors are based on concepts related to the "golden section", on studies made on the regular pentagon, on the spatial volumes able to be inscribed in spheres and on the tensegrity systems. The proposed structures present some advantages related to the ease of mounting, to the volume covered, to the resistance to the environmental factors (snow, wind, earthquake, and so on. The paper presents the conclusions of the investigations on the components of the spatial structures and on the outcomes of their use.

  3. Invisibility cloaking via non-smooth transformation optics and ray tracing

    International Nuclear Information System (INIS)

    Crosskey, Miles M.; Nixon, Andrew T.; Schick, Leland M.; Kovacic, Gregor

    2011-01-01

    We present examples of theoretically-predicted invisibility cloaks with shapes other than spheres and cylinders, including cones and ellipsoids, as well as shapes spliced from parts of these simpler shapes. In addition, we present an example explicitly displaying the non-uniqueness of invisibility cloaks of the same shape. We depict rays propagating through these example cloaks using ray tracing for geometric optics. - Highlights: → Theoretically-predicted conical and ellipsoidal invisibility cloaks. → Non-smooth cloaks spliced from parts of simpler shapes. → Example displaying non-uniqueness of invisibility cloaks of the same shape. → Rays propagating through example cloaks depicted using geometric optics.

  4. Acoustic invisibility cloaks of arbitrary shapes for complex background media

    Science.gov (United States)

    Zhu, Jian; Chen, Tianning; Liang, Qingxuan; Wang, Xiaopeng; Xiong, Jie; Jiang, Ping

    2016-04-01

    We report on the theoretical investigation of the acoustic cloaks working in complex background media in this paper. The constitutive parameters of arbitrary-shape cloaks are derived based on the transformation acoustic theory and coordinate transformation technique. The detailed analysis of boundaries conditions and potential applications of the cloaks are also presented in our work. To overcome the difficulty of achieving the materials with ideal parameters in nature, concentric alternating layered isotropic materials is adopted to approximate the required properties of the cloak. Theoretical design and excellent invisibility are demonstrated by numerical simulations. The inhomogeneous medium and arbitrary-shape acoustic cloaks grow closer to real application and may be a new hot spot in future.

  5. A two-component NZRI metamaterial based rectangular cloak

    Directory of Open Access Journals (Sweden)

    Sikder Sunbeam Islam

    2015-10-01

    Full Text Available A new two-component, near zero refractive index (NZRI metamaterial is presented for electromagnetic rectangular cloaking operation in the microwave range. In the basic design a pi-shaped, metamaterial was developed and its characteristics were investigated for the two major axes (x and z-axis wave propagation through the material. For the z-axis wave propagation, it shows more than 2 GHz bandwidth and for the x-axis wave propagation; it exhibits more than 1 GHz bandwidth of NZRI property. The metamaterial was then utilized in designing a rectangular cloak where a metal cylinder was cloaked perfectly in the C-band area of microwave regime. The experimental result was provided for the metamaterial and the cloak and these results were compared with the simulated results. This is a novel and promising design for its two-component NZRI characteristics and rectangular cloaking operation in the electromagnetic paradigm.

  6. Magnetic light cloaking control in the marine planktonic copepod Sapphirina

    Science.gov (United States)

    Kashiwagi, H.; Mizukawa, Y.; Iwasaka, M.; Ohtsuka, S.

    2017-05-01

    We investigated the light cloaking behavior of the marine planktonic copepod Sapphirina under a magnetic field. Optical interferences in the multi-laminated guanine crystal layer beneath the dorsal body surface create a brilliant structural color, which can be almost entirely removed by changing the light reflection. In the investigation, we immersed segments of Sapphirina in seawater contained in an optical chamber. When the derived Sapphirina segments were attached to the container surface, they were inert to magnetic fields up to 300 mT. However, when the back plate segments were attached to the substrate at a point, with most of the plate floating in the seawater, the plate rotated oppositely to the applied magnetic field. In addition, the brilliant parts of the Sapphirina back plate rotated backward and forward by changing the magnetic field directions. Our experiment suggests a new model of an optical micro-electro-mechanical system that is controllable by magnetic fields.

  7. Synthetic building materials for transport buildings and structures

    Science.gov (United States)

    Gerasimova, Vera

    2017-10-01

    The most effective building materials account for the highest growth not only in construction of residential and public buildings, but also other capital projects including roadways, bridges, drainage, communications and other engineering projects. Advancement in the technology of more efficient and ecologically responsible insulation materials have been a priority for safety, minimal maintenance and longevity of finished construction projects. The practical use of modern building materials such as insulation, sound reduction and low energy consumption are a benefit in cost and application compared to the use of outdated heavier and labor-intensive materials. The most efficient way for maximizing insolation and sound proofing should be done during the design stages of the project according to existing codes and regulations that are required by Western Government. All methods and materials that are used need to be optimized in order to reach a high durability and low operational and maintenance cost exceeding more than 50 years of the life of the building, whether it is for public, industrial or residential use. Western construction techniques and technologies need to be applied and adapted by the Russian Federation to insure the most productive successful methods are being implemented. The issues of efficient insulation materials are outlined in this article.

  8. Structural acceptance criteria Remote Handling Building Tritium Extraction Facility

    Energy Technology Data Exchange (ETDEWEB)

    Mertz, G.

    1999-12-16

    This structural acceptance criteria contains the requirements for the structural analysis and design of the Remote Handling Building (RHB) in the Tritium Extraction Facility (TEF). The purpose of this acceptance criteria is to identify the specific criteria and methods that will ensure a structurally robust building that will safely perform its intended function and comply with the applicable Department of Energy (DOE) structural requirements.

  9. Structural acceptance criteria Remote Handling Building Tritium Extraction Facility

    International Nuclear Information System (INIS)

    Mertz, G.

    1999-01-01

    This structural acceptance criteria contains the requirements for the structural analysis and design of the Remote Handling Building (RHB) in the Tritium Extraction Facility (TEF). The purpose of this acceptance criteria is to identify the specific criteria and methods that will ensure a structurally robust building that will safely perform its intended function and comply with the applicable Department of Energy (DOE) structural requirements

  10. Enhanced approximate cloaking by optimal change of variables

    International Nuclear Information System (INIS)

    Griesmaier, Roland; Vogelius, Michael S

    2014-01-01

    The aim of (passive) cloaking with respect to electromagnetic (or acoustic) sensing is to surround a region of space with a material layer—the cloak—that renders its contents and even the existence of the layer undetectable by such measurements. At least theoretically this can be achieved using the coordinate invariance of the underlying wave equation, through so-called cloaking by mapping. However, a practical realization of the cloaking by mapping schemes discussed in the literature frequently requires the design of highly anisotropic materials with extreme dielectric properties. In this work we consider, in the electrostatic case, a regularized, approximate cloaking by mapping scheme and discuss the problem of optimal choice of radial maps, that determine the conductivity distribution of the cloak. We consider two different optimality criteria: minimal maximal anisotropy and minimal mean anisotropy of this conductivity distribution. Using both criteria we show that it is possible to achieve significantly lower anisotropy (for a prescribed level of invisibility) or significantly lower visibility (for a prescribed level of anisotropy). For example, in two dimensions one may achieve exponentially small visibility with a cloak, that in terms of anisotropy (and lowest and highest conductivity) is no worse than the traditional affine map cloak, which only yields quadratically small visibility. (paper)

  11. Revival of cloaking effect in a driven bilayer graphene vector barrier

    Science.gov (United States)

    Maiti, S.; Panigrahi, A.; Biswas, R.; Sinha, C.

    2018-05-01

    Transmission profiles in bilayer graphene are studied theoretically through a rectangular vector potential (magnetic) barrier with and without the presence of an oscillatory potential. Unlike the electrostatic barrier, the Fano resonances (FR) are noted in the transmission spectra both for normal and glancing incidences due to non-conservation of chirality for a static vector barrier. The results for normal incidence indicate that the cloaking effect is a manifestation of the chirality conservation in charge transport through bilayer graphene scalar barriers. It is also noted that the aforesaid FR for a static vector barrier might disappear (photon induced electronic cloaking effect) due to the predominant photon exchange processes in presence of an external oscillating potential. The study of Fano resonances in transmission spectrum is in high demand in respect of localization of charge carriers in graphene nano structures for its potential applications in digital device fabrications.

  12. Cloaked Facebook pages: Exploring fake Islamist propaganda in social media

    DEFF Research Database (Denmark)

    Farkas, Johan Dam; Schou, Jannick; Neumayer, Christina

    2017-01-01

    This research analyses cloaked Facebook pages that are created to spread political propaganda by cloaking a user profile and imitating the identity of a political opponent in order to spark hateful and aggressive reactions. This inquiry is pursued through a multi-sited online ethnographic case...... study of Danish Facebook pages disguised as radical Islamist pages, which provoked racist and anti-Muslim reactions as well as negative sentiments towards refugees and immigrants in Denmark in general. Drawing on Jessie Daniels’ critical insights into cloaked websites, this research furthermore analyses...

  13. Open active cloaking and illusion devices for the Laplace equation

    International Nuclear Information System (INIS)

    Ma, Qian; Yang, Fan; Jin, Tian Yu; Mei, Zhong Lei; Cui, Tie Jun

    2016-01-01

    We propose open active cloaking and illusion devices for the Laplace equation. Compared with the closed configurations of active cloaking and illusion devices, we focus on improving the distribution schemes for the controlled sources, which do not have to surround the protected object strictly. Instead, the controlled sources can be placed in several small discrete clusters, and produce the desired voltages along the controlled boundary, to actively hide or disguise the protected object. Numerical simulations are performed with satisfactory results, which are further validated by experimental measurements. The open cloaking and illusion devices have many advantages over the closed configurations in various potential applications. (paper)

  14. Characteristic wave velocities in spherical electromagnetic cloaks

    International Nuclear Information System (INIS)

    Yaghjian, A D; Maci, S; Martini, E

    2009-01-01

    We investigate the characteristic wave velocities in spherical electromagnetic cloaks, namely, phase, ray, group and energy-transport velocities. After deriving explicit expressions for the phase and ray velocities (the latter defined as the phase velocity along the direction of the Poynting vector), special attention is given to the determination of group and energy-transport velocities, because a cursory application of conventional formulae for local group and energy-transport velocities can lead to a discrepancy between these velocities if the permittivity and permeability dyadics are not equal over a frequency range about the center frequency. In contrast, a general theorem can be proven from Maxwell's equations that the local group and energy-transport velocities are equal in linear, lossless, frequency dispersive, source-free bianisotropic material. This apparent paradox is explained by showing that the local fields of the spherical cloak uncouple into an E wave and an H wave, each with its own group and energy-transport velocities, and that the group and energy-transport velocities of either the E wave or the H wave are equal and thus satisfy the general theorem.

  15. Utilization of structural steel in buildings.

    Science.gov (United States)

    Moynihan, Muiris C; Allwood, Julian M

    2014-08-08

    Over one-quarter of steel produced annually is used in the construction of buildings. Making this steel causes carbon dioxide emissions, which climate change experts recommend be reduced by half in the next 37 years. One option to achieve this is to design and build more efficiently, still delivering the same service from buildings but using less steel to do so. To estimate how much steel could be saved from this option, 23 steel-framed building designs are studied, sourced from leading UK engineering firms. The utilization of each beam is found and buildings are analysed to find patterns. The results for over 10 000 beams show that average utilization is below 50% of their capacity. The primary reason for this low value is 'rationalization'-providing extra material to reduce labour costs. By designing for minimum material rather than minimum cost, steel use in buildings could be drastically reduced, leading to an equivalent reduction in 'embodied' carbon emissions.

  16. Mantle cloaks for elliptical cylinders excited by an electric line source

    DEFF Research Database (Denmark)

    Kaminski, Piotr Marek; Yakovlev, Alexander B.; Arslanagic, Samel

    2016-01-01

    We investigate the ability of surface impedance mantle cloaks for cloaking of elliptical cylinders excited by an electric line source. The exact analytical solution of the problem utilizing Mathieu functions is obtained and is used to derive optimal surface impedances to cloak a number of configu......We investigate the ability of surface impedance mantle cloaks for cloaking of elliptical cylinders excited by an electric line source. The exact analytical solution of the problem utilizing Mathieu functions is obtained and is used to derive optimal surface impedances to cloak a number...

  17. Cloaking of 2D particle geometries in a surface medium

    Energy Technology Data Exchange (ETDEWEB)

    Alexopoulos, A., E-mail: Aris.Alexopoulos@dsto.defence.gov.au [Electronic Warfare and Radar Division, Defence Science and Technology Organisation (DSTO), PO Box 1500, Edinburgh 5111 (Australia); Yau, K.S.B. [Electronic Warfare and Radar Division, Defence Science and Technology Organisation (DSTO), PO Box 1500, Edinburgh 5111 (Australia)

    2013-06-17

    We theoretically examine the cloaking condition for two-dimensional particles with varying geometry embedded inside a surface medium. General solutions are obtained for multi-layer particle configurations with either all positive or partially negative constitutive parameters respectively. Cloaking of particle geometries that are large relative to the incident wavelength is demonstrated. Theoretical predictions are compared to full-wave numerical simulations for arrays of particles consisting of different geometries.

  18. Transmutation of planar media singularities in a conformal cloak.

    Science.gov (United States)

    Liu, Yichao; Mukhtar, Musawwadah; Ma, Yungui; Ong, C K

    2013-11-01

    Invisibility cloaking based on optical transformation involves materials singularity at the branch cut points. Many interesting optical devices, such as the Eaton lens, also require planar media index singularities in their implementation. We show a method to transmute two singularities simultaneously into harmless topological defects formed by anisotropic permittivity and permeability tensors. Numerical simulation is performed to verify the functionality of the transmuted conformal cloak consisting of two kissing Maxwell fish eyes.

  19. Experimental demonstration of illusion optics with ``external cloaking'' effects

    Science.gov (United States)

    Li, Chao; Liu, Xiao; Liu, Guochang; Li, Fang; Fang, Guangyou

    2011-08-01

    A metamaterial "illusion optics" with "complementary medium" and "restoring medium" is designed by using inductor-capacitor (L-C) network medium. The unprecedented effects of "external cloaking" and "transforming one object to appear as another" are demonstrated experimentally. We also demonstrate that the non-resonant nature of the L-C network decreases the sensitivity of the "external cloaking" effect to the variation of the frequency and results in an acceptable bandwidth of the whole device.

  20. Electromagnetic cloaking devices for TE and TM polarizations

    International Nuclear Information System (INIS)

    Bilotti, Filiberto; Tricarico, Simone; Vegni, Lucio

    2008-01-01

    In this paper, we present the design of an electromagnetic cloaking device working for both transverse electric (TE) and transverse magnetic (TM) polarizations. The theoretical approach to cloaking used here is inspired by the one presented by Alu and Engheta (2005 Phys. Rev. E 72 016623) for TM polarization. The case of TE polarization is firstly considered and, then, an actual inclusion-based cloak for TE polarization is also designed. In such a case, the cloak is made of a mu-near-zero (MNZ) metamaterial, as the dual counterpart of the epsilon-near-zero (ENZ) material that can be used for purely dielectric objects. The operation and the robustness of the cloaking device for the TE polarization is deeply investigated through a complete set of full-wave numerical simulations. Finally, the design and an application of a cloak operating for both TE and TM polarizations employing both magnetic inclusions and the parallel plate medium already used by Silveirinha et al (Phys. Rev. E 75 036603) are presented.

  1. Experiments on Active Cloaking and Illusion for Laplace Equation

    Science.gov (United States)

    Ma, Qian; Mei, Zhong Lei; Zhu, Shou Kui; Jin, Tian Yu; Cui, Tie Jun

    2013-10-01

    In recent years, invisibility cloaks have received a lot of attention and interest. These devices are generally classified into two types: passive and active. The design and realization of passive cloaks have been intensively studied using transformation optics and plasmonic approaches. However, active cloaks are still limited to theory and numerical simulations. Here, we present the first experiment on active cloaking and propose an active illusion for the Laplace equation. We make use of a resistor network to simulate a conducting medium. Then, we surround the central region with controlled sources to protect it from outside detection. We show that by dynamically changing the controlled sources, the protected region can be cloaked or disguised as different objects (illusion). Our measurement results agree very well with numerical simulations. Compared with the passive counterparts, the active cloaking and illusion devices do not need complicated metamaterials. They are flexible, in-line controllable, and adaptable to the environment. In addition to dc electricity, the proposed method can also be used for thermodynamics and other problems governed by the Laplace equation.

  2. Source amplitudes for active exterior cloaking

    International Nuclear Information System (INIS)

    Norris, Andrew N; Amirkulova, Feruza A; Parnell, William J

    2012-01-01

    The active cloak comprises a discrete set of multipole sources that destructively interfere with an incident time harmonic scalar wave to produce zero total field over a finite spatial region. For a given number of sources and their positions in two dimensions it is shown that the multipole amplitudes can be expressed as infinite sums of the coefficients of the incident wave decomposed into regular Bessel functions. The field generated by the active sources vanishes in the infinite region exterior to a set of circles defined by the relative positions of the sources. The results provide a direct solution to the inverse problem of determining the source amplitudes. They also define a broad class of non-radiating discrete sources. (paper)

  3. Seismic Safety Margins Research Program (Phase I). Project IV. Structural building response; Structural Building Response Review

    International Nuclear Information System (INIS)

    Healey, J.J.; Wu, S.T.; Murga, M.

    1980-02-01

    As part of the Phase I effort of the Seismic Safety Margins Research Program (SSMRP) being performed by the University of California Lawrence Livermore Laboratory for the US Nuclear Regulatory Commission, the basic objective of Subtask IV.1 (Structural Building Response Review) is to review and summarize current methods and data pertaining to seismic response calculations particularly as they relate to the objectives of the SSMRP. This material forms one component in the development of the overall computational methodology involving state of the art computations including explicit consideration of uncertainty and aimed at ultimately deriving estimates of the probability of radioactive releases due to seismic effects on nuclear power plant facilities

  4. Elementary structural building blocks encountered in silicon surface reconstructions

    International Nuclear Information System (INIS)

    Battaglia, Corsin; Monney, Claude; Didiot, Clement; Schwier, Eike Fabian; Garnier, Michael Gunnar; Aebi, Philipp; Gaal-Nagy, Katalin; Onida, Giovanni

    2009-01-01

    Driven by the reduction of dangling bonds and the minimization of surface stress, reconstruction of silicon surfaces leads to a striking diversity of outcomes. Despite this variety even very elaborate structures are generally comprised of a small number of structural building blocks. We here identify important elementary building blocks and discuss their integration into the structural models as well as their impact on the electronic structure of the surface. (topical review)

  5. Possibility of perfect concealment by lossy conventional and lossy metamaterial cylindrical invisibility cloaks

    Science.gov (United States)

    Dehbashi, Reza; Shahabadi, Mahmoud

    2013-12-01

    The commonly used coordinate transformation for cylindrical cloaks is generalized. This transformation is utilized to determine an anisotropic inhomogeneous diagonal material tensors of a shell type cloak for various material types, i.e., double-positive (DPS: ɛ, μ > 0), double-negative (DNG: ɛ, μ cloaking for various material types, a rigorous analysis is performed. It is shown that perfect cloaking will be achieved for same type material for the cloak and its surrounding medium. Moreover, material losses are included in the analysis to demonstrate that perfect cloaking for lossy materials can be achieved for identical loss tangent of the cloak and its surrounding material. Sensitivity of the cloaking performance to losses for different material types is also investigated. The obtained analytical results are verified using a Finite-Element computational analysis.

  6. A 3D tunable and multi-frequency graphene plasmonic cloak

    KAUST Repository

    Farhat, Mohamed; Rockstuhl, Carsten; Bagci, Hakan

    2013-01-01

    We demonstrate the possibility of cloaking three-dimensional objects at multi-frequencies in the far-infrared part of the spectrum. The proposed cloaking mechanism exploits graphene layers wrapped around the object to be concealed. Graphene layers

  7. Internal structure of reactor building for Madras Atomic Power Project

    International Nuclear Information System (INIS)

    Pandit, D.P.

    1975-01-01

    The structural configuration and analysis of structural elements of the internal structure of reactor building for the Madras Atomic Power Project has been presented. Two methods of analysis of the internal structure, viz. Equivalent Plane Frame and Finite Element Method, are explained and compared with the use of bending moments obtained. (author)

  8. Building Investigation: Material or Structural Performance

    Directory of Open Access Journals (Sweden)

    Yusof M.Z.

    2014-03-01

    Full Text Available Structures such as roof trusses will not suddenly collapse without ample warning such as significant deflection, tilting etc. if the designer manages to avoid the cause of structural failure at the material level and the structural level. This paper outlines some principles and procedures of PDCA circle and QC tools which can show some clues of structural problems in terms of material or structural performance

  9. Iterative model building, structure refinement and density modification with the PHENIX AutoBuild wizard

    International Nuclear Information System (INIS)

    Terwilliger, Thomas C.; Grosse-Kunstleve, Ralf W.; Afonine, Pavel V.; Moriarty, Nigel W.; Zwart, Peter H.; Hung, Li-Wei; Read, Randy J.; Adams, Paul D.

    2008-01-01

    The highly automated PHENIX AutoBuild wizard is described. The procedure can be applied equally well to phases derived from isomorphous/anomalous and molecular-replacement methods. The PHENIX AutoBuild wizard is a highly automated tool for iterative model building, structure refinement and density modification using RESOLVE model building, RESOLVE statistical density modification and phenix.refine structure refinement. Recent advances in the AutoBuild wizard and phenix.refine include automated detection and application of NCS from models as they are built, extensive model-completion algorithms and automated solvent-molecule picking. Model-completion algorithms in the AutoBuild wizard include loop building, crossovers between chains in different models of a structure and side-chain optimization. The AutoBuild wizard has been applied to a set of 48 structures at resolutions ranging from 1.1 to 3.2 Å, resulting in a mean R factor of 0.24 and a mean free R factor of 0.29. The R factor of the final model is dependent on the quality of the starting electron density and is relatively independent of resolution

  10. Multicriteria Analysis of Assembling Buildings from Steel Frame Structures

    Science.gov (United States)

    Miniotaite, Ruta

    2017-10-01

    Steel frame structures are often used in the construction of public and industrial buildings. They are used for: all types of slope roofs; walls of newly-built public and industrial buildings; load bearing structures; roofs of renovated buildings. The process of assembling buildings from steel frame structures should be analysed as an integrated process influenced by such factors as construction materials and machinery used, the qualification level of construction workers, complexity of work, available finance. It is necessary to find a rational technological design solution for assembling buildings from steel frame structures by conducting a multiple criteria analysis. The analysis provides a possibility to evaluate the engineering considerations and find unequivocal solutions. The rational alternative of a complex process of assembling buildings from steel frame structures was found through multiple criteria analysis and multiple criteria evaluation. In multiple criteria evaluation of technological solutions for assembling buildings from steel frame structures by pairwise comparison method the criteria by significance are distributed as follows: durability is the most important criterion in the evaluation of alternatives; the price (EUR/unit of measurement) of a part of assembly process; construction workers’ qualification level (category); mechanization level of a part of assembling process (%), and complexity of assembling work (in points) are less important criteria.

  11. Monitoring of Building Structure by Tiltsensors

    Directory of Open Access Journals (Sweden)

    Alojz Kopáčik

    2005-06-01

    Full Text Available This paper discusses about the dynamic monitoring of stability (tilt measurement of bearing pillar of high-rise building using the electronic measuring system. The electronic measuring system consists of Libela 2800 tilt sensor, input/output device for the AE 2DN tilt sensor, measuring amplifier and also the Spider8 analog/digital converter and the registration equipment (notebook. The basic part of uniaxial tilt sensor creates a frame, on which is among damping plates hung a pendulum (ferromagnetic kernel. The tilt value is determined on a principle of electromagnetic induction by changing the position of ferromagnetic kernel in the reel. The range of pendulum movement is ± 2,5 mm/m and the accuracy of the tilt determination is 0,001 mm/m. The monitored building represents, from the point of constructional view, a ferro-concrete rectangular sceleton, which consists of vertical bearing pillars, on which are guyed longitudinal and transverse girders. The building ground-plan is rectangular with the dimensions of 75 m (distance and 12 m (width. The building has two underground and six above the ground floors with constructional high of 3,40 m. Whole highth of the above ground part of building is 20,4 m. The pillar tilt was measured in the transverse direction of the building at the level of the second floor using the Libela 2800 electronic sensor. The sensor was situated on the metallic console (L-profile, which was assembled on a lateral side of the circuit bearing pillar at the highth of 8,3 m above the ground level. Together with the tilt monitoring, the outside air temperature in the close area of pillar was measured. The tilt measurement was carried out continuously for 168 hours with the recording frequency of 1 Hz (1 measurement/second. The file of the measured data with 603 950 records was reduced to the file with 1006 records, which corresponds to the record of the every tenth minute. The measured tilt values represent from the

  12. Building with electromagnetic shield structure for individual floors

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, T; Nakamura, M; Yabana, Y; Ishikawa, T; Nagata, K

    1991-09-10

    This invention relates to a building having a floor-by-floor electromagnetic shield structure well-suited for application to an information network system in which an electromagnetically shielded space is divided by individual floors and electric waves are utilized within the building on a floor-by-floor basis. (author). 8 figs.

  13. Radar Mapping of Building Structures Applying Sparse Reconstruction

    NARCIS (Netherlands)

    Tan, R.G.; Wit, J.J.M. de; Rossum, W.L. van

    2012-01-01

    The ability to map building structures at a certain stand-off distance allows intelligence, reconnaissance, and clearance tasks to be performed in a covert way by driving around a building. This will greatly improve security, response time, and reliability of aforementioned tasks. Therefore,

  14. Building with electromagnetic shield structure for individual floors

    International Nuclear Information System (INIS)

    Takahashi, T.; Nakamura, M.; Yabana, Y.; Ishikawa, T.; Nagata, K.

    1991-01-01

    This invention relates to a building having a floor-by-floor electromagnetic shield structure well-suited for application to an information network system in which an electromagnetically shielded space is divided by individual floors and electric waves are utilized within the building on a floor-by-floor basis. (author). 8 figs

  15. Structural evaluation of the 2736Z Building for seismic loads

    International Nuclear Information System (INIS)

    Giller, R.A.

    1994-01-01

    The 2736Z building structure is evaluated for high-hazard loads. The 2736Z building is analyzed herein for normal and seismic loads and is found to successfully meet the guidelines of UCRL-15910 along with the related codes requirements

  16. Environmental effect of structural solutions and building materials to a building

    International Nuclear Information System (INIS)

    Haapio, Appu; Viitaniemi, Pertti

    2008-01-01

    The field of building environmental assessment tools has become a popular research area over the past decade. However, how the service life of a building affects the results of the environmental assessment of a building has not been emphasised previously. The aim of this study is to analyse how different structural solutions and building materials affect the results of the environmental assessment of a whole building over the building's life cycle. Furthermore, how the length of the building's service life affects the results is analysed. The environmental assessments of 78 single-family houses were calculated for this study. The buildings have different wall insulations, claddings, window frames, and roof materials, and the length of the service life varies from 60 years up to 160 years. The current situation and the future of the environmental assessment of buildings are discussed. In addition, topics for further research are suggested; for example, how workmanship affects the service life and the environmental impact of a building should be studied

  17. Iterative model-building, structure refinement, and density modification with the PHENIX AutoBuild Wizard

    Energy Technology Data Exchange (ETDEWEB)

    Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545, USA; Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720, USA; Department of Haematology, University of Cambridge, Cambridge CB2 0XY, England; Terwilliger, Thomas; Terwilliger, T.C.; Grosse-Kunstleve, Ralf Wilhelm; Afonine, P.V.; Moriarty, N.W.; Zwart, P.H.; Hung, L.-W.; Read, R.J.; Adams, P.D.

    2007-04-29

    The PHENIX AutoBuild Wizard is a highly automated tool for iterative model-building, structure refinement and density modification using RESOLVE or TEXTAL model-building, RESOLVE statistical density modification, and phenix.refine structure refinement. Recent advances in the AutoBuild Wizard and phenix.refine include automated detection and application of NCS from models as they are built, extensive model completion algorithms, and automated solvent molecule picking. Model completion algorithms in the AutoBuild Wizard include loop-building, crossovers between chains in different models of a structure, and side-chain optimization. The AutoBuild Wizard has been applied to a set of 48 structures at resolutions ranging from 1.1 {angstrom} to 3.2 {angstrom}, resulting in a mean R-factor of 0.24 and a mean free R factor of 0.29. The R-factor of the final model is dependent on the quality of the starting electron density, and relatively independent of resolution.

  18. Intelligent seismic risk mitigation system on structure building

    Science.gov (United States)

    Suryanita, R.; Maizir, H.; Yuniorto, E.; Jingga, H.

    2018-01-01

    Indonesia located on the Pacific Ring of Fire, is one of the highest-risk seismic zone in the world. The strong ground motion might cause catastrophic collapse of the building which leads to casualties and property damages. Therefore, it is imperative to properly design the structural response of building against seismic hazard. Seismic-resistant building design process requires structural analysis to be performed to obtain the necessary building responses. However, the structural analysis could be very difficult and time consuming. This study aims to predict the structural response includes displacement, velocity, and acceleration of multi-storey building with the fixed floor plan using Artificial Neural Network (ANN) method based on the 2010 Indonesian seismic hazard map. By varying the building height, soil condition, and seismic location in 47 cities in Indonesia, 6345 data sets were obtained and fed into the ANN model for the learning process. The trained ANN can predict the displacement, velocity, and acceleration responses with up to 96% of predicted rate. The trained ANN architecture and weight factors were later used to build a simple tool in Visual Basic program which possesses the features for prediction of structural response as mentioned previously.

  19. PS buildings : reinforced concrete structure for shielding "bridge" pillar

    CERN Multimedia

    CERN PhotoLab

    1956-01-01

    The PS ring traverses the region between the experimental halls South and North (buildings Nos 150 and 151) under massive bridge-shaped concrete beams. This pillar stands at the S-W end of the structure.

  20. Invisible anti-cloak with elliptic cross section using phase complement

    International Nuclear Information System (INIS)

    Yang Yu-Qi; Zhang Min; Yue Jian-Xiang

    2011-01-01

    Based on the theory of phase complement, an anti-cloak with circular cross section can be made invisible to an object outside its domain. As the cloak with elliptic cross section is more effective to make objects invisible than that with circular cross section, a scaled coordinate system is proposed to design equivalent materials of invisible anti-cloak with elliptic cross section using phase complement. The cloaks with conventional dielectric and double negative parameters are both simulated with the geometrical transformations. The results show that the cloak with elliptic cross section through phase complement can effectively hide the outside objects. (classical areas of phenomenology)

  1. Broadband three-dimensional diamond-shaped invisible cloaks composed of tetrahedral homogeneous blocks

    International Nuclear Information System (INIS)

    Wang Xinhua; Qu Shaobo; Wu Xiang; Wang Jiafu; Ma Hua; Xu Zhuo

    2010-01-01

    By means of embedded optical transformation, three-dimensional diamond-shaped invisible cloaks composed of tetrahedral homogeneous blocks have been designed in this paper. The constitutive parameters of the invisible cloaks can be obtained based on the form invariance of Maxwell's equations in coordinate transformation. Numerical methods using the finite element method verified the diamond-shaped cloaks. The invisible properties of the designed cloaks are nearly perfect when the original line section is sufficiently short compared with its counterpart in the after-transformed space. The designed cloaks can operate in a wide bandwidth due to the line transformation in the coordinate transformation process.

  2. Spherical cloaking using nonlinear transformations for improved segmentation into concentric isotropic coatings.

    Science.gov (United States)

    Qiu, Cheng-Wei; Hu, Li; Zhang, Baile; Wu, Bae-Ian; Johnson, Steven G; Joannopoulos, John D

    2009-08-03

    Two novel classes of spherical invisibility cloaks based on nonlinear transformation have been studied. The cloaking characteristics are presented by segmenting the nonlinear transformation based spherical cloak into concentric isotropic homogeneous coatings. Detailed investigations of the optimal discretization (e.g., thickness control of each layer, nonlinear factor, etc.) are presented for both linear and nonlinear spherical cloaks and their effects on invisibility performance are also discussed. The cloaking properties and our choice of optimal segmentation are verified by the numerical simulation of not only near-field electric-field distribution but also the far-field radar cross section (RCS).

  3. Material parameters characterization for arbitrary N-sided regular polygonal invisible cloak

    International Nuclear Information System (INIS)

    Wu Qun; Zhang Kuang; Meng Fanyi; Li Lewei

    2009-01-01

    Arbitrary N-sided regular polygonal cylindrical cloaks are proposed and designed based on the coordinate transformation theory. First, the general expressions of constitutive tensors of the N-sided regular polygonal cylindrical cloaks are derived, then there are some full-wave simulations of the cloaks that are composed of inhomogeneous and anisotropic metamaterials, which will bend incoming electromagnetic waves and guide them to propagate around the inner region; such electromagnetic waves will return to their original propagation directions without distorting the waves outside the polygonal cloak. The results of full-wave simulations validate the general expressions of constitutive tensors of the N-sided regular polygonal cylindrical cloaks we derived.

  4. Structural response of steel high rise buildings to fire

    DEFF Research Database (Denmark)

    Gentili, Filippo; Giuliani, Luisa; Bontempi, Franco

    2013-01-01

    Due to the significant vertical elevation and complexity of the structural system, high rise buildings may suffer from the effects of fire more than other structures. For this reason, in addition to evacuation strategies and active fire protection, a careful consideration of structural response t...

  5. Mantle cloaking for co-site radio-frequency antennas

    Energy Technology Data Exchange (ETDEWEB)

    Monti, Alessio, E-mail: alessio.monti@uniroma3.it; Barbuto, Mirko [“Niccolò Cusano” University, Via Don Carlo Gnocchi 3, Rome 00166 (Italy); Soric, Jason; Alù, Andrea [Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Ramaccia, Davide; Vellucci, Stefano; Toscano, Alessandro; Bilotti, Filiberto [Department of Engineering, “Roma Tre” University, Via Vito Volterra 62, Rome 00146 (Italy); Trotta, Fabrizio [Antenna Department, ELETTRONICA S.p.A., Via Tiburtina Valeria Km 13700, Rome 00131 (Italy)

    2016-03-14

    We show that properly designed mantle cloaks, consisting of patterned metallic sheets placed around cylindrical monopoles, allow tightly packing the same antennas together in a highly dense telecommunication platform. Our experimental demonstration is applied to the relevant example of two cylindrical monopole radiators operating for 3G and 4G mobile communications. The two antennas are placed in close proximity, separated by 1/10 of the shorter operational wavelength, and, after cloaking, are shown to remarkably operate as if isolated in free-space. This result paves the way to unprecedented co-siting strategies for multiple antennas handling different services and installed in overcrowded platforms, such as communication towers, satellite payloads, aircrafts, or ship trees. More broadly, this work presents a significant application of cloaking technology to improve the efficiency of modern communication systems.

  6. Mantle cloaking for co-site radio-frequency antennas

    International Nuclear Information System (INIS)

    Monti, Alessio; Barbuto, Mirko; Soric, Jason; Alù, Andrea; Ramaccia, Davide; Vellucci, Stefano; Toscano, Alessandro; Bilotti, Filiberto; Trotta, Fabrizio

    2016-01-01

    We show that properly designed mantle cloaks, consisting of patterned metallic sheets placed around cylindrical monopoles, allow tightly packing the same antennas together in a highly dense telecommunication platform. Our experimental demonstration is applied to the relevant example of two cylindrical monopole radiators operating for 3G and 4G mobile communications. The two antennas are placed in close proximity, separated by 1/10 of the shorter operational wavelength, and, after cloaking, are shown to remarkably operate as if isolated in free-space. This result paves the way to unprecedented co-siting strategies for multiple antennas handling different services and installed in overcrowded platforms, such as communication towers, satellite payloads, aircrafts, or ship trees. More broadly, this work presents a significant application of cloaking technology to improve the efficiency of modern communication systems.

  7. A metasurface carpet cloak for electromagnetic, acoustic and water waves.

    Science.gov (United States)

    Yang, Yihao; Wang, Huaping; Yu, Faxin; Xu, Zhiwei; Chen, Hongsheng

    2016-01-29

    We propose a single low-profile skin metasurface carpet cloak to hide objects with arbitrary shape and size under three different waves, i.e., electromagnetic (EM) waves, acoustic waves and water waves. We first present a metasurface which can control the local reflection phase of these three waves. By taking advantage of this metasurface, we then design a metasurface carpet cloak which provides an additional phase to compensate the phase distortion introduced by a bump, thus restoring the reflection waves as if the incident waves impinge onto a flat mirror. The finite element simulation results demonstrate that an object can be hidden under these three kinds of waves with a single metasurface cloak.

  8. FEM Updating of the Heritage Court Building Structure

    DEFF Research Database (Denmark)

    Ventura, C. E.; Brincker, Rune; Dascotte, E.

    2001-01-01

    . The starting model of the structure was developed from the information provided in the design documentation of the building. Different parameters of the model were then modified using an automated procedure to improve the correlation between measured and calculated modal parameters. Careful attention......This paper describes results of a model updating study conducted on a 15-storey reinforced concrete shear core building. The output-only modal identification results obtained from ambient vibration measurements of the building were used to update a finite element model of the structure...

  9. Folded Plate Structures as Building Envelopes

    DEFF Research Database (Denmark)

    Falk, Andreas; Buelow, Peter von; Kirkegaard, Poul Henning

    2012-01-01

    This paper treats applications of cross-laminated timber (CLT) in structural systems for folded façade solutions. Previous work on CLT-based systems for folded roofs has shown a widening range of structural possibilities to develop timber-based shells. Geometric and material properties play...... CLT-based systems, which are studied and analysed by using a combination of digital tools for structural and environmental design and analysis. The results show gainful, rational properties of folded systems and beneficial effects from an integration of architectural and environmental performance...... criteria in the design of CLT-based façades....

  10. Level Set-Based Topology Optimization for the Design of an Electromagnetic Cloak With Ferrite Material

    DEFF Research Database (Denmark)

    Otomori, Masaki; Yamada, Takayuki; Andkjær, Jacob Anders

    2013-01-01

    . A level set-based topology optimization method incorporating a fictitious interface energy is used to find optimized configurations of the ferrite material. The numerical results demonstrate that the optimization successfully found an appropriate ferrite configuration that functions as an electromagnetic......This paper presents a structural optimization method for the design of an electromagnetic cloak made of ferrite material. Ferrite materials exhibit a frequency-dependent degree of permeability, due to a magnetic resonance phenomenon that can be altered by changing the magnitude of an externally...

  11. A unidirectional acoustic cloak for multilayered background media with homogeneous metamaterials

    Science.gov (United States)

    Zhu, Jian; Chen, Tianning; Liang, Qingxuan; Wang, Xiaopeng; Xiong, Jie; Jiang, Ping

    2015-08-01

    The acoustic cloak, which can make an object hard to detect acoustically in a homogeneous background, has attracted great attention from researchers in recent years. The inhomogeneous background media were considered in this paper. The relative constitutive parameters were derived for acoustic cloaks working in multilayered media. And a unidirectional acoustic cloak for layered background media was proposed, designed and implemented successfully in a wide frequency range. In water and NaCl aqueous solution, the acoustic cloak was designed and realized with homogeneous metamaterials which were composed of steel and porous materials. The effective parameters of the unit cells of the cloak were determined by using the effective medium theory. Numerical results demonstrated excellent cloaking performance and showed that such a device could be physically realized with natural materials which will greatly promote the real applications of an invisibility cloak in inhomogeneous backgrounds.

  12. A unidirectional acoustic cloak for multilayered background media with homogeneous metamaterials

    International Nuclear Information System (INIS)

    Zhu, Jian; Chen, Tianning; Liang, Qingxuan; Wang, Xiaopeng; Xiong, Jie; Jiang, Ping

    2015-01-01

    The acoustic cloak, which can make an object hard to detect acoustically in a homogeneous background, has attracted great attention from researchers in recent years. The inhomogeneous background media were considered in this paper. The relative constitutive parameters were derived for acoustic cloaks working in multilayered media. And a unidirectional acoustic cloak for layered background media was proposed, designed and implemented successfully in a wide frequency range. In water and NaCl aqueous solution, the acoustic cloak was designed and realized with homogeneous metamaterials which were composed of steel and porous materials. The effective parameters of the unit cells of the cloak were determined by using the effective medium theory. Numerical results demonstrated excellent cloaking performance and showed that such a device could be physically realized with natural materials which will greatly promote the real applications of an invisibility cloak in inhomogeneous backgrounds. (paper)

  13. Optical force on a discrete invisibility cloak in time-dependent fields

    International Nuclear Information System (INIS)

    Chaumet, Patrick C.; Zolla, Frederic; Nicolet, Andre; Belkebir, Kamal; Rahmani, Adel

    2011-01-01

    We study, in time domain, the exchange of momentum between an electromagnetic pulse and a three-dimensional, discrete, spherical invisibility cloak. We find that a discrete cloak, initially at rest, would experience an electromagnetic force due to the pulse but would acquire zero net momentum and net displacement. On the other hand, we find that while the cloak may manage to conceal an object and shroud it from the electromagnetic forces associated with the pulse, the cloak itself can experience optomechanical stress on a scale much larger than the object would in the absence of the cloak. We also consider the effects of material dispersion and losses on the electromagnetic forces experienced by the cloak and show that they lead to a transfer of momentum from the pulse to the cloak.

  14. Assessment of structural reliability of precast concrete buildings

    Directory of Open Access Journals (Sweden)

    Koyankin Alexandr

    2018-01-01

    Full Text Available Precast housing construction is currently being under rapid development, however, reliability of building structures made from precast reinforced concrete cannot be assessed rationally due to insufficient research data on that subject. In this regard, experimental and numerical studies were conducted to assess structural reliability of precast buildings as described in the given paper. Experimental studies of full-scale and model samples were conducted; numerical studies were held based on finite element models using “Lira” software. The objects under study included fragment of flooring of a building under construction, full-size fragment of flooring, full-scale models of precast cross-beams-to-columns joints and joints between hollow-core floor slabs and precast and cast-in-place cross-beams. Conducted research enabled to perform an objective assessment of structural reliability of precast buildings.

  15. Thermal invisibility based on scattering cancellation and mantle cloaking

    KAUST Repository

    Farhat, Mohamed; Chen, P.-Y.; Bagci, Hakan; Amra, C.; Guenneau, S.; Alù , A.

    2015-01-01

    We theoretically and numerically analyze thermal invisibility based on the concept of scattering cancellation and mantle cloaking. We show that a small object can be made completely invisible to heat diffusion waves, by tailoring the heat conductivity of the spherical shell enclosing the object. This means that the thermal scattering from the object is suppressed, and the heat flow outside the object and the cloak made of these spherical shells behaves as if the object is not present. Thermal invisibility may open new vistas in hiding hot spots in infrared thermography, military furtivity, and electronics heating reduction.

  16. A dc carpet cloak based on resistor networks.

    Science.gov (United States)

    Mei, Zhong Lei; Liu, Yu Sha; Yang, Fan; Cui, Tie Jun

    2012-11-05

    We propose, design, and implement a two-dimensional dc carpet cloak for steady electric field using the transformation optics (TO) method. Based on the circuit theory, we introduce a resistor network to mimic the resulting anisotropic conducting medium. The experimental prototype is fabricated using metal film resistors, and the measured results agree perfectly well with theoretical predictions. This study gives the first experimental verification of a dc carpet cloak, which expands the application of TO theory, and has potential applications in related areas.

  17. Thermal invisibility based on scattering cancellation and mantle cloaking

    KAUST Repository

    Farhat, Mohamed

    2015-04-30

    We theoretically and numerically analyze thermal invisibility based on the concept of scattering cancellation and mantle cloaking. We show that a small object can be made completely invisible to heat diffusion waves, by tailoring the heat conductivity of the spherical shell enclosing the object. This means that the thermal scattering from the object is suppressed, and the heat flow outside the object and the cloak made of these spherical shells behaves as if the object is not present. Thermal invisibility may open new vistas in hiding hot spots in infrared thermography, military furtivity, and electronics heating reduction.

  18. Manipulating the loss in electromagnetic cloaks for perfect wave absorption.

    Science.gov (United States)

    Argyropoulos, Christos; Kallos, Efthymios; Zhao, Yan; Hao, Yang

    2009-05-11

    We examine several ways to manipulate the loss in electro-magnetic cloaks, based on transformation electromagnetics. It is found that, by utilizing inherent electric and magnetic losses of metamaterials, perfect wave absorption can be achieved based on several popular designs of electromagnetic cloaks. A practical implementation of the absorber, consisting of ten discrete layers of metamaterials, is proposed. The new devices demonstrate super-absorptivity over a moderate wideband range, suitable for both microwave and optical applications. It is corroborated that the device is functional with a subwavelength thickness and, hence, advantageous compared to the conventional absorbers.

  19. Performance evaluation of existing building structure with pushover analysis

    Science.gov (United States)

    Handana, MAP; Karolina, R.; Steven

    2018-02-01

    In the management of the infrastructure of the building, during the period of buildings common building damage as a result of several reasons, earthquakes are common. The building is planned to work for a certain service life. But during the certain service life, the building vulnerable to damage due to various things. Any damage to cultivate can be detected as early as possible, because the damage could spread, triggering and exacerbating the latest. The newest concept to earthquake engineering is Performance Based Earthquake Engineering (PBEE). PBEE divided into two, namely Performance Based Seismic Design (PBSD) and Performance Based Seismic Evaluation (PBSE). Evaluation on PBSE one of which is the analysis of nonlinear pushover. Pushover analysis is a static analysis of nonlinear where the influence of the earthquake plan on building structure is considered as burdens static catch at the center of mass of each floor, which it was increased gradually until the loading causing the melting (plastic hinge) first within the building structure, then the load increases further changes the shapes of post-elastic large it reached the condition of elastic. Then followed melting (plastic hinge) in the location of the other structured.

  20. Structure of pool in reactor building

    International Nuclear Information System (INIS)

    Yokoyama, Shigeki.

    1997-01-01

    Shielding walls made of iron-reinforced concrete having a metal liner including two body walls rigidly combined to the upper surface of a reactor container are disposed at least to one of an equipment pool or spent fuel storage pool in a reactor building. A rack for temporarily placing an upper lattice plate is detachably attached at least above one of a steam dryer or a gas/liquid separator temporarily placed in the temporary pool, and the height from the bottom portion to the upper end of the shielding wall is determined based on the height of an upper lattice plate temporary placed on the rack and the water depth required for shielding radiation from the upper lattice plate. An operator's exposure on the operation floor can be reduced by the shielding wall, and radiation dose from the spent fuels is reduced. The increase of the height of a pool guarder enhances bending resistance as a ceiling. In addition, the total height of them is made identical with the depth of the spent fuel storage pool thereby enabling to increase storage area for spent fuels. (N.H.)

  1. Structuring oil by protein building blocks

    NARCIS (Netherlands)

    Vries, de Auke

    2017-01-01

    Over the recent years, structuring of oil into ‘organogels’ or ‘oleogels’ has gained much attention amongst colloid-, material,- and food scientists. Potentially, these oleogels could be used as an alternative for saturated- and trans fats in food products. To develop oleogels as a

  2. Building nuclear structures : challenges and achievements

    International Nuclear Information System (INIS)

    Gad, V.M.

    1981-01-01

    Reliability and safety are factors of prime importance in construction of civil engineering structures of nuclear facilities. There cannot be any compromise in the strength and life of the structure. This involves rigorous control of: (1) quality of materials and end products, (2) time taken for construction, (3) cost, and also continuing innovation. India has now accumulated more than three decades of experience in nuclear civil engineering and the civil engineering fraternity of India and particularly of the Department of Atomic Energy is now fully capable of designing and construction of all types of structures involved in the nuclear field. Illustrative examples are given. Dome of the CIRUS reactor was constructed in steel plates, but then there was a switch over to reinforced concrete for containment structures and subsequently to prestressed concrete. The aspects taken into consideration of the design to ensure absolute leak tightness are: (1) earthquake safeguards, (2) concrete surface protection, and (3) minimization of cracking in concrete due to pressure loading and shrinkage. Coordination charts are prepared for monitoring time required for various operations and time and motion studies are employed to cut down on construction time. Close control over the cost is kept through internal and external audit, executing the work departmentally or employing an outside agency as the occasion demands and proper selection of materials. Some of the innovations in materials use and construction techniques are mentioned. (K.M.)

  3. Automated detection of repeated structures in building facades

    Directory of Open Access Journals (Sweden)

    M. Previtali

    2013-10-01

    Full Text Available Automatic identification of high-level repeated structures in 3D point clouds of building façades is crucial for applications like digitalization and building modelling. Indeed, in many architectural styles building façades are governed by arrangements of objects into repeated patterns. In particular, façades are generally designed as the repetition of some few basic objects organized into interlaced and\\or concatenated grid structures. Starting from this key observation, this paper presents an algorithm for Repeated Structure Detection (RSD in 3D point clouds of building façades. The presented methodology consists of three main phases. First, in the point cloud segmentation stage (i the building façade is decomposed into planar patches which are classified by means of some weak prior knowledge of urban buildings formulated in a classification tree. Secondly (ii, in the element clustering phase detected patches are grouped together by means of a similarity function and pairwise transformations between patches are computed. Eventually (iii, in the structure regularity estimation step the parameters of repeated grid patterns are calculated by using a Least- Squares optimization. Workability of the presented approach is tested using some real data from urban scenes.

  4. Flood damage to historic buildings and structures

    Czech Academy of Sciences Publication Activity Database

    Drdácký, Miloš

    2010-01-01

    Roč. 24, č. 5 (2010), s. 439-445 ISSN 0887-3828 Grant - others:evropská komise(XE) FP6 Project cultural heritage protection against flood CHEF-SSPI-044251 Institutional research plan: CEZ:AV0Z20710524 Keywords : flood impact * historic structures * damage category Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 0.293, year: 2010

  5. Coevolutionary and genetic algorithm based building spatial and structural design

    NARCIS (Netherlands)

    Hofmeyer, H.; Davila Delgado, J.M.

    2015-01-01

    In this article, two methods to develop and optimize accompanying building spatial and structural designs are compared. The first, a coevolutionary method, applies deterministic procedures, inspired by realistic design processes, to cyclically add a suitable structural design to the input of a

  6. Effect of structural design on traffic-induced building vibrations

    DEFF Research Database (Denmark)

    Persson, Peter; Andersen, Lars Vabbersgaard; Persson, Kent

    2017-01-01

    Population growth and urbanization results in densified cities, where new buildings are being built closer to existing vibration sources such as road-, tram- and rail traffic. In addition, new transportation systems are constructed closer to existing buildings. Potential disturbing vibrations...... are one issue to consider in planning urban environment and densification of cities. Vibrations can be disturbing for humans but also for sensitive equipment in, for example, hospitals. In determining the risk for disturbing vibrations, the distance between the source and the receiver, the ground...... properties, and type and size of the building are governing factors. In the paper, a study is presented aiming at investigating the influence of various parameters of the building's structural design on vibration levels in the structure caused by ground surface loads, e.g. traffic. Parameters studied...

  7. Dynamic analysis of clustered building structures using substructures methods

    International Nuclear Information System (INIS)

    Leimbach, K.R.; Krutzik, N.J.

    1989-01-01

    The dynamic substructure approach to the building cluster on a common base mat starts with the generation of Ritz-vectors for each building on a rigid foundation. The base mat plus the foundation soil is subjected to kinematic constraint modes, for example constant, linear, quadratic or cubic constraints. These constraint modes are also imposed on the buildings. By enforcing kinematic compatibility of the complete structural system on the basis of the constraint modes a reduced Ritz model of the complete cluster is obtained. This reduced model can now be analyzed by modal time history or response spectrum methods

  8. Phonons as building blocks in nuclear structure

    International Nuclear Information System (INIS)

    Silvestre-Brac, B.

    1980-01-01

    The structure of a nuclear system in terms of eigenmodes (phonons) of subsystems is investigated in three different approaches. In the frame of nuclear field theory the three identical particle system is analysed and the elimination of spurious states due to the violation of the Pauli principle is emphasized. In terms of weak coupling, a new approach of the shell model is proposed which is shown to be rapidly convergent with the number of basis vectors. Applications of three particle systems in the lead region are made. Lastly, a microscopic multiphonon theorie of collective K=0 states in deformed nuclei based on a Tamm Dancoff phonon is developed. The role of the Pauli principle as well as comparisons with boson expansion methods are deeply analysed [fr

  9. Seismic safety of building structures of NPP Kozloduy III

    International Nuclear Information System (INIS)

    Varbanov, G.I.; Kostov, M.K.; Stefanov, D.D.; Kaneva, A.D.

    2005-01-01

    In the proposed paper is presented a general summary of the analyses carried out to evaluate the dynamic behavior and to assess the seismic safety of some safety related building structures of NPP Kozloduy. The design seismic loads for the site of Kozloduy NPP has been reevaluated and increased during and after the construction of investigated Units 5 and 6. Deterministic and probabilistic approaches are applied to assess the seismic vulnerability of the investigated structures, taking into account the newly defined seismic excitations. The presented results show sufficient seismic safety for the studied critical structures and good efficiency of the seismic upgrading. The applicability of the investigated structures at sites with some higher seismic activities is discussed. The presented study is dealing mainly with the civil structures of the Reactor building, Turbine hall, Diesel Generator Station and Water Intake Structure. (authors)

  10. Automated and fast building of three-dimensional RNA structures.

    Science.gov (United States)

    Zhao, Yunjie; Huang, Yangyu; Gong, Zhou; Wang, Yanjie; Man, Jianfen; Xiao, Yi

    2012-01-01

    Building tertiary structures of non-coding RNA is required to understand their functions and design new molecules. Current algorithms of RNA tertiary structure prediction give satisfactory accuracy only for small size and simple topology and many of them need manual manipulation. Here, we present an automated and fast program, 3dRNA, for RNA tertiary structure prediction with reasonable accuracy for RNAs of larger size and complex topology.

  11. Structural integrity analysis of an INPP building under external loading

    International Nuclear Information System (INIS)

    Dundulis, G.; Karalevicius, R.; Uspuras, E.; Kulak, R.F.; Marchertas, A.

    2005-01-01

    After the terrorist attacks in New York and Washington D. C. using civil airplanes, the evaluation of civil airplane crashes into civil and NPP structures has become very important. The interceptions of many terrorists' communications reveal that the use of commandeered commercial aircraft is still a major part of their plans for destruction. Aircraft crash or other flying objects in the territory of the Ignalina Nuclear Power Plant (INPP) represents a concern to the plant. Aircraft traveling at high velocity have a destructive potential. The aircraft crash may damage the roof and walls of buildings, pipelines, electric motors, cases of power supplies, power cables of electricity transmission and other elements and systems, which are important for safety. Therefore, the evaluation of the structural response to an of aircraft crash is important and was selected for analysis. The structural integrity analysis due to the effects of an aircraft crash on an NPP building structure is the subject of this paper. The finite element method was used for the structural analysis of a typical Ignalina NPP building. The structural integrity analysis was performed for a portion of the ALS using the dynamic loading of an aircraft crash impact model. The computer code NEPTUNE was used for this analysis. The local effects caused by impact of the aircraft's engine on the building wall were evaluated independently by using an empirical formula. (authors)

  12. KEY ASPECTS OF ENSURING ENERGY EFFICIENCY OF BUILDINGS AND STRUCTURES

    Directory of Open Access Journals (Sweden)

    S.G. Abramyan

    2017-06-01

    Full Text Available The paper is based on the review of the foreign and national academic literature and intended to emphasize the issues of ensuring energy efficiency of buildings and structures applicable to all the countries as for reconstruction of existing buildings as for erection of new ones . The author highlights the key aspects of the provision of energy efficiency of buildings and structures in some foreign countries. The conclusion is made that the studies are mainly aimed at discovering new heat insulation materials, whereby polystyrene insulation is found to be the most widespread wall insulation material in a number of countries. At the same time, it is observed that the ongoing research is focused on solutions to optimize the structure of walling systems in terms of both insulant thickness and the number and sequence of insulation layers in the walling structure. A conclusion is made that hyper insulation of external walls leads to considerable expenses arising due to cooling during the summer season. The use of prefabricated vacuum panels as a heat insulation layer and off-the-shelf single-layer structures, subject to their heat insulation characteristics, appears a more constructive way to meet the energy efficiency requirements, as the arrangement of ideal air space in multilayered walls proves a significant challenge today. One of the most promising ways to ensure energy efficiency is the use of multifunctional polyvalent walls and provision of polyvalent heat supply from renewable energy sources. Since energy efficiency depends on the spatial arrangement of buildings, construction must ensure a minimum ratio of the area of enclosing structures to the overall building volume (by adding on new facilities in case of reconstruction. It is noted that a systemic approach to ensuring energy efficiency of buildings is impossible without proper regard to the environmental parameters of heat insulation materials.

  13. Graphene based metamaterials for terahertz cloaking and subwavelength imaging

    Science.gov (United States)

    Forouzmand, Seyedali

    Graphene is a two-dimensional carbon crystal that became one of the most controversial topics of research in the last few years. The intense interest in graphene stems from recent demonstrations of their potentially revolutionary electromagnetic applications -- including negative refraction, subdiffraction imaging, and even invisibility -- which have suggested a wide range of new devices for communications, sensing, and biomedicine. In addition, it has been shown that graphene is amenable to unique patterning schemes such as cutting, bending, folding, and fusion that are predicted to lead to interesting properties. A recent proposed application of graphene is in engineering the scattering properties of objects, which may be leveraged in applications such as radar-cross-section management and stealth, where it may be required to make one object look like another object or render an object completely invisible. We present the analytical formulation for the analysis of electromagnetic interaction with a finite conducting wedge covered with a cylindrically shaped nanostructured graphene metasurface, resulting in the scattering cancellation of the dominant scattering mode for all the incident and all the observation angles. Following this idea, the cylindrical graphene metasurface is utilized for cloaking of several concentric finite conducting wedges. In addition, a wedge shaped metasurface is proposed as an alternative approach for cloaking of finite wedges. The resolution of the conventional imaging lenses is restricted by the natural diffraction limit. Artificially engineered metamaterials now offer the possibility of creating a superlens that overcomes this restriction. We demonstrate that a wire medium (WM) slab loaded with graphene sheets enables the enhancement of the near field for subwavelength imaging at terahertz (THz) frequencies. The analysis is based on the nonlocal homogenization model for WM with the additional boundary condition in the connection of

  14. Damping in building structures during earthquakes: test data and modeling

    International Nuclear Information System (INIS)

    Coats, D.W. Jr.

    1982-01-01

    A review and evaluation of the state-of-the-art of damping in building structures during earthquakes is presented. The primary emphasis is in the following areas: 1) the evaluation of commonly used mathematical techniques for incorporating damping effects in both simple and complex systems; 2) a compilation and interpretation of damping test data; and 3) an evaluation of structure testing methods, building instrumentation practices, and an investigation of rigid-body rotation effects on damping values from test data. A literature review provided the basis for evaluating mathematical techiques used to incorporate earthquake induced damping effects in simple and complex systems. A discussion on the effectiveness of damping, as a function of excitation type, is also included. Test data, from a wide range of sources, has been compiled and interpreted for buidings, nuclear power plant structures, piping, equipment, and isolated structural elements. Test methods used to determine damping and frequency parameters are discussed. In particular, the advantages and disadvantages associated with the normal mode and transfer function approaches are evaluated. Additionally, the effect of rigid-body rotations on damping values deduced from strong-motion building response records is investigated. A discussion of identification techniques typically used to determine building parameters (frequency and damping) from strong motion records is included. Finally, an analytical demonstration problem is presented to quantify the potential error in predicting fixed-base structural frequency and damping values from strong motion records, when rigid-body rotations are not properly accounted for

  15. Deployable bamboo structure project: A building life-cycle report

    Science.gov (United States)

    Firdaus, Adrian; Prastyatama, Budianastas; Sagara, Altho; Wirabuana, Revian N.

    2017-11-01

    Bamboo is considered as a sustainable material in the world of construction, and it is vastly available in Indonesia. The general utilization of the material is increasingly frequent, however, its usage as a deployable structure-a recently-developed use of bamboo, is still untapped. This paper presents a report on a deployable bamboo structure project, covering the entire building life-cycle phase. The cycle encompasses the designing; fabrication; transportation; construction; operation and maintenance; as well as a plan for future re-use. The building is made of a configuration of the structural module, each being a folding set of bars which could be reduced in size to fit into vehicles for easy transportation. Each structural module was made of Gigantochloa apus bamboo. The fabrication, transportation, and construction phase require by a minimum of three workers. The fabrication and construction phase require three hours and fifteen minutes respectively. The building is utilized as cafeteria stands, the operation and maintenance phase started since early March 2017. The maintenance plan is scheduled on a monthly basis, focusing on the inspection of the locking mechanism element and the entire structural integrity. The building is designed to allow disassembly process so that it is reusable in the future.

  16. Analysis of the structural design process of the adaptive reuse of building structures

    NARCIS (Netherlands)

    Pasterkamp, S.

    2014-01-01

    In the field of structural building engineering there is a market shift taking place as a result of the growing number of buildings that are listed as cultural heritage, secularization, the economic situation and the increasing office vacancy rate in Europe and the US. More and more structural

  17. Design of a broadband ultra-large area acoustic cloak based on a fluid medium

    Science.gov (United States)

    Zhu, Jian; Chen, Tianning; Liang, Qingxuan; Wang, Xiaopeng; Jiang, Ping

    2014-10-01

    A broadband ultra-large area acoustic cloak based on fluid medium was designed and numerically implemented with homogeneous metamaterials according to the transformation acoustics. In the present work, fluid medium as the body of the inclusion could be tuned by changing the fluid to satisfy the variant acoustic parameters instead of redesign the whole cloak. The effective density and bulk modulus of the composite materials were designed to agree with the parameters calculated from the coordinate transformation methodology by using the effective medium theory. Numerical simulation results showed that the sound propagation and scattering signature could be controlled in the broadband ultra-large area acoustic invisibility cloak, and good cloaking performance has been achieved and physically realized with homogeneous materials. The broadband ultra-large area acoustic cloaking properties have demonstrated great potentials in the promotion of the practical applications of acoustic cloak.

  18. A 3D tunable and multi-frequency graphene plasmonic cloak

    KAUST Repository

    Farhat, Mohamed

    2013-01-01

    We demonstrate the possibility of cloaking three-dimensional objects at multi-frequencies in the far-infrared part of the spectrum. The proposed cloaking mechanism exploits graphene layers wrapped around the object to be concealed. Graphene layers are doped via a variable external voltage difference permitting continuous tuning of the cloaking frequencies. Particularly, two configurations are investigated: (i) Only one graphene layer is used to suppress the scattering from a dielectric sphere. (ii) Several of these layers biased at different gate voltages are used to achieve a multi-frequency cloak. These frequencies can be set independently. The proposed cloak\\'s functionality is verified by near- and far-field computations. By considering geometry and material parameters that are realizable by practical experiments, we contribute to the development of graphene based plasmonic applications that may find use in disruptive photonic technologies. © 2013 Optical Society of America.

  19. A Review of Influence of Various Types of Structural Bracing to the Structural Performance of Buildings

    Science.gov (United States)

    Razak, S. M.; Kong, T. C.; Zainol, N. Z.; Adnan, A.; Azimi, M.

    2018-03-01

    Excessive lateral drift can contribute significantly towards crack formation, leading to structural damage. The structural damage will in turn reduce the capacity of the structure and weaken it from the intended design capacity. Generally, lateral drift is more pronounced in higher and longer structure, such as high rise buildings and bridges. A typical method employed to control lateral drift is structural bracing, which works by increasing stiffness and stability of structure. This paper reviews the influence of various types of structural bracing to structural performance of buildings. The history of structural bracing is visited and the differences between numerous structural bracing in term of suitability to different types of buildings and loading, mechanisms, technical details, advantages and limitations, and the overall effect on the structural behaviour and performance are dissected. Proper and efficient structural bracing is pertinent for each high rise building as this will lead towards safer, sustainable and more economical buildings, which are cheaper to maintain throughout the life of the buildings in the future.

  20. Historic Structure Assessment for Building 839, Carlisle Barracks: Carlisle, Pennsylvania

    Science.gov (United States)

    2017-10-01

    Restoration Reconstruction Stabilization Condition Assessment Standard Definitions Qualitative Condition Ratings Maintenance Deficiency Priority...Structure Name Building 839 Other Name(s) Farmhouse Location Patton Road Carlisle Barracks Cumberland County, Pennsylvania Date of Construction ca...that guide the project; 4. Condition Assessment Survey: architectural fabric survey and assessment, summary of condition ratings, and maintenance

  1. Structure Building Predicts Grades in College Psychology and Biology

    Science.gov (United States)

    Arnold, Kathleen M.; Daniel, David B.; Jensen, Jamie L.; McDaniel, Mark A.; Marsh, Elizabeth J.

    2016-01-01

    Knowing what skills underlie college success can allow students, teachers, and universities to identify and to help at-risk students. One skill that may underlie success across a variety of subject areas is structure building, the ability to create mental representations of narratives (Gernsbacher, Varner, & Faust, 1990). We tested if…

  2. Measuring structural (un)safety in the Dutch building industry

    NARCIS (Netherlands)

    Terwel, K.C.; Waarts, P; E Rademaeker, de

    2010-01-01

    The last 10 years the Dutch Building Industry was shocked by several major accidents. In 2001 the steel structure of a theatre in Hoorn collapsed during erection. No one was hurt, because it collapsed during the night. In 2002 part of the parking deck of a hotel collapsed just some time after a

  3. Structural capacity assessment of machine-building enterprises and associations

    Directory of Open Access Journals (Sweden)

    Prilutskay Maria

    2017-01-01

    Full Text Available Multidirectional tendencies of machine-building enterprises integration and disintegration resulted in the emergence of the formal and informal associations. These associations consist of the obviously and/or implicitly affiliated legal entities. Thus, a new element appears in the direct enterprise environment, i.e a management company or a head enterprise. The management company influences the participants even in an informal association. New environment restrictions led to the changes in the management structure. The paper considers the enterprise structures interrelation: organizational, financial, production, resource, and others. The authors draw a conclusion that the structures are hierarchy, and there are the coherence structures assessment criteria. The coordinated structures form the structural capacity of the enterprise. The suggested assessment coherence criteria (for example resource and functional structures allow estimating the structural potential and defining the directions of the enterprise efficiency increase.

  4. Dynamic soil-structure interactions on embedded buildings

    International Nuclear Information System (INIS)

    Kobarg, J.; Werkle, H.; Henseleit, O.

    1983-01-01

    The dynamic soil-structure interaction on the horizontal seismic excitation is investigated on two typical embedded auxiliary buildings of a nuclear power plant. The structure and the soil are modelled by various analytical and numerical methods. Under the condition of the linear viscoelastic theory, i.e. soil characteristic constant in time and independent of strain, the interaction influences between a homogenous soil layer and a structure are analysied for the following parameters: 4) mathematical soil modells; 4) mathematical structure modells; 4) shear wave velocities; 3) embedment conditions; 4) earthquake time histories. (orig.) [de

  5. Full control and manipulation of heat signatures: cloaking, camouflage and thermal metamaterials.

    Science.gov (United States)

    Han, Tiancheng; Bai, Xue; Thong, John T L; Li, Baowen; Qiu, Cheng-Wei

    2014-03-19

    Thermal camouflage and cloaking can transform an actual heat signature into a pre-controlled one. A viable recipe for controlling and manipulating heat signatures using thermal metamaterials to empower cloaking and camouflage in heat conduction is demonstrated. The thermal signature of the object is thus metamorphosed and perceived as multiple targets with different geometries and compositions, with the original object cloaked. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. The scattering of a cylindrical invisibility cloak: reduced parameters and optimization

    DEFF Research Database (Denmark)

    Peng, Liang; Ran, L.; Mortensen, Asger

    2011-01-01

    We investigate the scattering of 2D cylindrical invisibility cloaks with simplified constitutive parameters with the assistance of scattering coefficients. We show that the scattering of the cloaks originates not only from the boundary conditions but also from the spatial variation of the component...... of permittivity/permeability. According to our formulation, we propose some restrictions to the invisibility cloak in order to minimize its scattering after the simplification has taken place. With our theoretical analysis, it is possible to design a simplified cloak using some peculiar composites...

  7. Magnetically controlled multifrequency invisibility cloak with a single shell of ferrite material

    Science.gov (United States)

    Wang, Xiaohua; Liu, Youwen

    2015-02-01

    A magnetically controlled multifrequency invisibility cloak with a single shell of the isotropic and homogeneous ferrite material has been investigated based on the scattering cancellation method from the Mie scattering theory. The analytical and simulated results have demonstrated that such this shell can drastically reduce the total scattering cross-section of this cloaking system at multiple frequencies. These multiple cloaking frequencies of this shell can be externally controlled since the magnetic permeability of ferrites is well tuned by the applied magnetic field. This may provide a potential way to design a tunable multifrequency invisibility cloak with considerable flexibility.

  8. Invisibility cloaks with arbitrary geometries for layered and gradually changing backgrounds

    International Nuclear Information System (INIS)

    Li, C; Yao, K; Li, F

    2009-01-01

    Cloaks with arbitrary geometries are proposed which can make objects invisible in inhomogeneous backgrounds. The general and explicit expressions of the complex permittivity and permeability tensors are derived for cloaks embedded in layered and gradually changing media. The inner and the outer boundaries of the cloaks can be non-conformal with arbitrary shapes, which considerably improve the flexibility of the cloak applications. The interactions of electromagnetic waves with irregular cloaks are studied based on numerical simulations. The influences of the cloaked and uncloaked perfect electric conductor (PEC) cylinders upon the scattering fields of the multilayered backgrounds are quantitatively evaluated. The effect of loss on the cloaking performance has also been investigated. It is verified that cloaks with ideal parameters can smoothly deflect and guide the incoming beams to propagate around the shielded regions without disturbing the beams when they return to the inhomogeneous backgrounds. Therefore, the objects in the shielded region can be effectively invisible to the corresponding backgrounds. The performance of lossy cloaks will degrade with comparatively large power reduction of the transmitted beams.

  9. Two-dimensional arbitrarily shaped acoustic cloaks composed of homogeneous parts

    Science.gov (United States)

    Li, Qi; Vipperman, Jeffrey S.

    2017-10-01

    Acoustic cloaking is an important application of acoustic metamaterials. Although the topic has received much attention, there are a number of areas where contributions are needed. In this paper, a design method for producing acoustic cloaks with arbitrary shapes that are composed of homogeneous parts is presented. The cloak is divided into sections, each of which, in turn, is further divided into two parts, followed by the application of transformation acoustics to derive the required properties for cloaking. With the proposed mapping relations, the properties of each part of the cloak are anisotropic but homogeneous, which can be realized using two alternating layers of homogeneous and isotropic materials. A hexagonal and an irregular cloak are presented as design examples. The full wave simulations using COMSOL Multiphysics finite element software show that the cloaks function well at reducing reflections and shadows. The variation of the cloak properties is investigated as a function of three important geometric parameters used in the transformations. A balance can be found between cloaking performance and materials properties that are physically realizable.

  10. Design of the Coordinate Transformation Function for Cylindrical Acoustic Cloaks with a Quantity of Discrete Layers

    International Nuclear Information System (INIS)

    Cai Li; Wen Ji-Hong; Yu Dian-Long; Lu Zhi-Miao; Wen Xi-Sen

    2014-01-01

    Acoustic cloak based on coordinate transformation is of great topical interest and has promise in potential applications such as sound transparency and insulation. The frequency response of acoustic cloaks with a quantity of discrete homogeneous layers is analyzed by the acoustic scattering theory. The effect of coordinate transformation function on the acoustic total scattering cross section is discussed to achieve low scattering with only a few layers of anisotropic metamaterials. Also, the physics of acoustic wave interaction with the interfaces between the discrete layers inside the cloak shell is discussed. These results provide a better way of designing a multilayered acoustic cloak with fewer layers. (fundamental areas of phenomenology(including applications))

  11. Design of the Coordinate Transformation Function for Cylindrical Acoustic Cloaks with a Quantity of Discrete Layers

    Science.gov (United States)

    Cai, Li; Wen, Ji-Hong; Yu, Dian-Long; Lu, Zhi-Miao; Wen, Xi-Sen

    2014-09-01

    Acoustic cloak based on coordinate transformation is of great topical interest and has promise in potential applications such as sound transparency and insulation. The frequency response of acoustic cloaks with a quantity of discrete homogeneous layers is analyzed by the acoustic scattering theory. The effect of coordinate transformation function on the acoustic total scattering cross section is discussed to achieve low scattering with only a few layers of anisotropic metamaterials. Also, the physics of acoustic wave interaction with the interfaces between the discrete layers inside the cloak shell is discussed. These results provide a better way of designing a multilayered acoustic cloak with fewer layers.

  12. Models test on dynamic structure-structure interaction of nuclear power plant buildings

    International Nuclear Information System (INIS)

    Kitada, Y.; Hirotani, T.

    1999-01-01

    A reactor building of an NPP (nuclear power plant) is generally constructed closely adjacent to a turbine building and other buildings such as the auxiliary building, and in increasing numbers of NPPs, multiple plants are being planned and constructed closely on a single site. In these situations, adjacent buildings are considered to influence each other through the soil during earthquakes and to exhibit dynamic behaviour different from that of separate buildings, because those buildings in NPP are generally heavy and massive. The dynamic interaction between buildings during earthquake through the soil is termed here as 'dynamic cross interaction (DCI)'. In order to comprehend DCI appropriately, forced vibration tests and earthquake observation are needed using closely constructed building models. Standing on this background, Nuclear Power Engineering Corporation (NUPEC) had planned the project to investigate the DCI effect in 1993 after the preceding SSI (soil-structure interaction) investigation project, 'model tests on embedment effect of reactor building'. The project consists of field and laboratory tests. The field test is being carried out using three different building construction conditions, e.g. a single reactor building to be used for the comparison purposes as for a reference, two same reactor buildings used to evaluate pure DCI effects, and two different buildings, reactor and turbine building models to evaluate DCI effects under the actual plant conditions. Forced vibration tests and earthquake observations are planned in the field test. The laboratory test is planned to evaluate basic characteristics of the DCI effects using simple soil model made of silicon rubber and structure models made of aluminum. In this test, forced vibration tests and shaking table tests are planned. The project was started in April 1994 and will be completed in March 2002. This paper describes an outline and the summary of the current status of this project. (orig.)

  13. Criteria of choosing building structures for rooftop boiler rooms

    Directory of Open Access Journals (Sweden)

    Plotnikov Artyom

    2018-01-01

    Full Text Available The paper investigates parameters of noise and vibration distribution in the territory of residential area depending on the structural materials and power of independent heat supply systems. Rooftop boiler rooms are decentralized heat supply systems in buildings. Today, residential areas are strongly affected by noise and vibrations. Adverse effects are isolated by buildings materials, protective shields and floating floors. Rooftop boiler rooms located in Tyumen city were investigated within this research. Structures of rooftop boiler rooms were analyzed. Acoustic analysis results and the parameters of equivalent continuous sound level are presented. An option for improvement of rooftop boiler rooms structures is suggested. Comparison of capital investments in construction and installation activities is carried out. Conclusion on capital investments required for noise protection is made.

  14. Life management for a non replaceable structure: the reactor building

    International Nuclear Information System (INIS)

    Torres, V.; Francia, L.

    1998-01-01

    Phase 1 of UNESA N.P.P. Lifetime Management Project identified and ranked important components, relative to plant life management. The list showed the Reactor Containment Structure in the third position, and thirteen concrete structures were among the list top twenty. Since the Reactor Containment Building, together with the Reactor Vessel, is the only non-replaceable plant component, and has a big impact on the plant technical life, there is an increasing interest on understanding its behavior to maintain structural integrity. This paper presents: a) IAEA (International Atomic Energy Agency) Coordinated Research Program experiences and studies. Under this Program, international experts address the most frequent degradation mechanisms affecting the containment building. b) IAEA Aging Management Program adapted to our plants. The paper addresses the aging mechanisms affecting the concrete structures, reinforcing steel and prestress systems as well as the aging management programs and the mitigation and control methods. Finally, this paper presents a new module called STRUCTURES, included in phase 2 of the above mentioned project, which will monitor and document the different aging mechanisms and management programs described in item b) regarding the Reactor Containment Building (concrete liner, post stressing system, anchor elements). This module will also support the Maintenance Rule related practices. (Author)

  15. Structural design of SBWR reactor building complex using microcomputers

    International Nuclear Information System (INIS)

    Mandagi, K.; Rajagopal, R.S.; Sawhney, P.S.; Gou, P.F.

    1993-01-01

    The design concept of Simplified Boiling Water Reactor (SBWR) plant is based on simplicity and passive features to enhance safety and reliability, improve performance, and increase economic viability. The SBWR utilizes passive systems such as Gravity Driven Core-Cooling System (GDCS) and Passive Containment Cooling System (PCCS). To suit these design features the Reactor Building (RB) complex of the SBWR is configured as an integrated structure consisting of a cylindrical Reinforced Concrete Containment Vessel (RCCV) surrounded by square reinforced concrete safety envelope and outer box structures, all sharing a common reinforced concrete basemat. This paper describes the structural analysis and design aspects of the RB complex. A 3D STARDYNE finite element model has been developed for the structural analysis of the complex using a PC Compaq 486/33L microcomputer. The structural analysis is performed for service and factored load conditions for the applicable loading combinations. The dynamic responses of containment structures due to pool hydrodynamic loads have been calculated by an axisymmetric shell model using COSMOS/M program. The RCCV is designed in accordance with ASME Section 3, Division 2 Code. The rest of the RB which is classified as Seismic Category 1 structure is designed in accordance with the ACI 349 Code. This paper shows that microcomputers can be efficiently used for the analysis and design of large and complex structures such as RCCV and Reactor Building complex. The use of microcomputers can result in significant savings in the computational cost compared with that of mainframe computers

  16. Salt Damage and Rising Damp Treatment in Building Structures

    Directory of Open Access Journals (Sweden)

    J. M. P. Q. Delgado

    2016-01-01

    Full Text Available Salt damage can affect the service life of numerous building structures, both historical and contemporary, in a significant way. In this review, various damage mechanisms to porous building materials induced by salt action are analyzed. The importance of pretreatment investigations is discussed as well; in combination with the knowledge of salt and moisture transport mechanisms they can give useful indications regarding treatment options. The methods of salt damage treatment are assessed then, including both passive techniques based on environmental control, reduction of water transport, or conversion to less soluble salts and active procedures resulting in the removal of salts from deterioration zones. It is concluded that cellulose can still be considered as the favorite material presently used in desalination poultices but hydrophilic mineral wool can serve as its prospective alternative in future applications. Another important cause of building pathologies is the rising damp and, in this phenomenon, it is particularly severe considering the presence of salts in water. The treatment of rising damp in historic building walls is a very complex procedure and at Laboratory of Building Physics (LFC-FEUP a wall base hygroregulated ventilation system was developed and patented.

  17. Multi functional roof structures of the energy efficient buildings

    Directory of Open Access Journals (Sweden)

    Krstić Aleksandra

    2006-01-01

    Full Text Available Modern architectural concepts, which are based on rational energy consumption of buildings and the use of solar energy as a renewable energy source, give the new and significant role to the roofs that become multifunctional structures. Various energy efficient roof structures and elements, beside the role of protection, provide thermal and electric energy supply, natural ventilation and cooling of a building, natural lighting of the indoor space sunbeam protection, water supply for technical use, thus according to the above mentioned functions, classification and analysis of such roof structures and elements are made in this paper. The search for new architectural values and optimization in total energy balance of a building or the likewise for the urban complex, gave to roofs the role of "climatic membranes". Contemporary roof forms and materials clearly exemplify their multifunctional features. There are numerous possibilities to achieve the new and attractive roof design which broadens to the whole construction. With such inducement, this paper principally analyze the configuration characteristics of the energy efficient roof structures and elements, as well as the visual effects that may be achieved by their application.

  18. Assessment of Technogenic Accident Risk of Industrial Building Structures

    Science.gov (United States)

    Baiburin, D. A.; Baiburin, A. Kh

    2017-11-01

    A methodology for assessing the risk of an industrial building accident was developed taking into account the damage caused by various localization of collapse. Before the beginning of the survey of a facility technical condition, groups including the same type of building structures are selected. Further, assessment is made for the reduction in their load-carrying capacity from the strength and stability conditions taking into account defects. The characteristics of the influence of defects and structural damage on a building safety is the degree of compliance with the standards expressed by the reliability level. Reliability levels assignment is carried out on the basis of calculations, operating experience and inspection of a particular type of structure according to the formalized rules. The risk of collapse according to a separate scenario is calculated for structures that are capable and incapable of causing a progressive ossification. The results of the technique application are based on the analysis of the accident risk at the welding shop “Vysota (Height) 239” of the Chelyabinsk Pipe Rolling Plant.

  19. Direct Georeferencing of Uav Data Based on Simple Building Structures

    Science.gov (United States)

    Tampubolon, W.; Reinhardt, W.

    2016-06-01

    Unmanned Aerial Vehicle (UAV) data acquisition is more flexible compared with the more complex traditional airborne data acquisition. This advantage puts UAV platforms in a position as an alternative acquisition method in many applications including Large Scale Topographical Mapping (LSTM). LSTM, i.e. larger or equal than 1:10.000 map scale, is one of a number of prominent priority tasks to be solved in an accelerated way especially in third world developing countries such as Indonesia. As one component of fundamental geospatial data sets, large scale topographical maps are mandatory in order to enable detailed spatial planning. However, the accuracy of the products derived from the UAV data are normally not sufficient for LSTM as it needs robust georeferencing, which requires additional costly efforts such as the incorporation of sophisticated GPS Inertial Navigation System (INS) or Inertial Measurement Unit (IMU) on the platform and/or Ground Control Point (GCP) data on the ground. To reduce the costs and the weight on the UAV alternative solutions have to be found. This paper outlines a direct georeferencing method of UAV data by providing image orientation parameters derived from simple building structures and presents results of an investigation on the achievable results in a LSTM application. In this case, the image orientation determination has been performed through sequential images without any input from INS/IMU equipment. The simple building structures play a significant role in such a way that geometrical characteristics have been considered. Some instances are the orthogonality of the building's wall/rooftop and the local knowledge of the building orientation in the field. In addition, we want to include the Structure from Motion (SfM) approach in order to reduce the number of required GCPs especially for the absolute orientation purpose. The SfM technique applied to the UAV data and simple building structures additionally presents an effective tool

  20. A magnetic field cloak for charged particle beams

    Science.gov (United States)

    Capobianco-Hogan, K. G.; Cervantes, R.; Deshpande, A.; Feege, N.; Krahulik, T.; LaBounty, J.; Sekelsky, R.; Adhyatman, A.; Arrowsmith-Kron, G.; Coe, B.; Dehmelt, K.; Hemmick, T. K.; Jeffas, S.; LaByer, T.; Mahmud, S.; Oliveira, A.; Quadri, A.; Sharma, K.; Tishelman-Charny, A.

    2018-01-01

    Shielding charged particle beams from transverse magnetic fields is a common challenge for particle accelerators and experiments. We demonstrate that a magnetic field cloak is a viable solution. It allows for the use of dipole magnets in the forward regions of experiments at an Electron Ion Collider (EIC) and other facilities without interfering with the incoming beams. The dipoles can improve the momentum measurements of charged final state particles at angles close to the beam line and therefore increase the physics reach of these experiments. In contrast to other magnetic shielding options (such as active coils), a cloak requires no external powering. We discuss the design parameters, fabrication, and limitations of a magnetic field cloak and demonstrate that cylinders made from 45 layers of YBCO high-temperature superconductor, combined with a ferromagnetic shell made from epoxy and stainless steel powder, shield more than 99% of a transverse magnetic field of up to 0.45 T (95% shielding at 0.5 T) at liquid nitrogen temperature. The ferromagnetic shell reduces field distortions caused by the superconductor alone by 90% at 0.45 T.

  1. Seismic response analysis of an instrumented building structure

    Science.gov (United States)

    Li, H.-J.; Zhu, S.-Y.; Celebi, M.

    2003-01-01

    The Sheraton - Universal hotel, an instrumented building lying in North Hollywood, USA is selected for case study in this paper. The finite element method is used to produce a linear time - invariant structural model, and the SAP2000 program is employed for the time history analysis of the instrumented structure under the base excitation of strong motions recorded in the basement during the Northridge, California earthquake of 17 January 1994. The calculated structural responses are compared with the recorded data in both time domain and frequency domain, and the effects of structural parameters evaluation and indeterminate factors are discussed. Some features of structural response, such as the reason why the peak responses of acceleration in the ninth floor are larger than those in the sixteenth floor, are also explained.

  2. Study on reactor building structure using ultrahigh strength materials, 1

    International Nuclear Information System (INIS)

    Ishimura, Kikuo; Odajima, Masahiro; Irino, Kazuo; Hashiba, Toshio.

    1991-01-01

    This study was promoted to be aimed at realization of the optimal nuclear reactor building structure of the future. As the first step, the study regarding ultrahigh strength reinforced concrete (abbr. RC) shear wall was selected. As the result of various tests, the application of ultrahigh strength RC shear walls was verified. The tests conducted were relevant to; ultrahigh strength concrete material tests; pure shear tests of RC flat panels; and bending shear tests and its simulation analysis of RC shear walls. (author)

  3. Ambient Response Analysis of the Heritage Court Tower Building Structure

    DEFF Research Database (Denmark)

    Brincker, Rune; Andersen, Palle

    2000-01-01

    In this paper an ambient response analysis of the Heritage Court Building structure is presented. The work is a part of a blind test organized by Professor Carlos Ventura, University of British Columbia. The response data were analyses using two different techniques: a non-parametric based on Fre...... modes, natural frequencies identified by the two techniques shoved good agreement, mode shape estimates were nearly identical, and damping ratios reasonably close and around 1-2% in the most cases....

  4. Ambient Response Analysis of the Heritage Court Tower Building Structure

    DEFF Research Database (Denmark)

    Brincker, Rune; Andersen, Palle

    2000-01-01

    In this paper an ambient response analysis of the Heritage Court Building structure is presented. The work is a part of a blind test organized by Professor Carlos Ventura, University of British Columbia. The response data were analyses using two different techniques: a non-parametric based...... modes, natural frequencies identified by the two techniques shoved good agreement, mode shape estimates were nearly identical, and damping ratios reasonably close and around 1-2% in the most cases....

  5. Structural Analysis and Seismic Design for Cold Neutron Laboratory Building

    International Nuclear Information System (INIS)

    Wu, Sangik; Kim, Y. K.; Kim, H. R.

    2007-05-01

    This report describes all the major results of the dynamic structural analysis and seismic design for the Cold Neutron Laboratory Building which is classified in seismic class II. The results are summarized of the ground response spectrum as seismic input loads, mechanical properties of subsoil, the buoyancy stability due to ground water, the maximum displacement of the main frame under the seismic load and the member design. This report will be used as a basic design report to maintenance its structural integrity in future

  6. DIRECT GEOREFERENCING OF UAV DATA BASED ON SIMPLE BUILDING STRUCTURES

    Directory of Open Access Journals (Sweden)

    W. Tampubolon

    2016-06-01

    Full Text Available Unmanned Aerial Vehicle (UAV data acquisition is more flexible compared with the more complex traditional airborne data acquisition. This advantage puts UAV platforms in a position as an alternative acquisition method in many applications including Large Scale Topographical Mapping (LSTM. LSTM, i.e. larger or equal than 1:10.000 map scale, is one of a number of prominent priority tasks to be solved in an accelerated way especially in third world developing countries such as Indonesia. As one component of fundamental geospatial data sets, large scale topographical maps are mandatory in order to enable detailed spatial planning. However, the accuracy of the products derived from the UAV data are normally not sufficient for LSTM as it needs robust georeferencing, which requires additional costly efforts such as the incorporation of sophisticated GPS Inertial Navigation System (INS or Inertial Measurement Unit (IMU on the platform and/or Ground Control Point (GCP data on the ground. To reduce the costs and the weight on the UAV alternative solutions have to be found. This paper outlines a direct georeferencing method of UAV data by providing image orientation parameters derived from simple building structures and presents results of an investigation on the achievable results in a LSTM application. In this case, the image orientation determination has been performed through sequential images without any input from INS/IMU equipment. The simple building structures play a significant role in such a way that geometrical characteristics have been considered. Some instances are the orthogonality of the building’s wall/rooftop and the local knowledge of the building orientation in the field. In addition, we want to include the Structure from Motion (SfM approach in order to reduce the number of required GCPs especially for the absolute orientation purpose. The SfM technique applied to the UAV data and simple building structures additionally presents an

  7. Radon entry into buildings: Effects of atmospheric pressure fluctuations and building structural factors

    International Nuclear Information System (INIS)

    Robinson, A.L.

    1996-05-01

    An improved understanding of the factors that control radon entry into buildings is needed in order to reduce the public health risks caused by exposure to indoor radon. This dissertation examines three issues associated with radon entry into buildings: (1) the influence of a subslab gravel layer and the size of the openings between the soil and the building interior on radon entry; (2) the effect of atmospheric pressure fluctuations on radon entry; and (3) the development and validation of mathematical models which simulate radon and soil-gas entry into houses. Experiments were conducted using two experimental basements to examine the influence of a subslab gravel layer on advective radon entry driven by steady indoor-outdoor pressure differences. These basement structures are identical except that in one the floor slab lies directly on native soil whereas in the other the slab lies on a high-permeability gravel layer. The measurements indicate that a high permeability subslab gravel layer increases the advective radon entry rate into the structure by as much as a factor of 30. The magnitude of the enhancement caused by the subslab gravel layer depends on the area of the openings in the structure floor; the smaller the area of these openings the larger the enhancement in the radon entry rate caused by the subslab gravel layer. A three-dimensional, finite-difference model correctly predicts the effect of a subslab gravel layer and open area configuration on advective radon entry driven by steady indoor-outdoor pressure differences; however, the model underpredicts the absolute entry rate into each structure by a factor of 1.5

  8. Radon entry into buildings: Effects of atmospheric pressure fluctuations and building structural factors

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Allen Lantham [Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering

    1996-05-01

    An improved understanding of the factors that control radon entry into buildings is needed in order to reduce the public health risks caused by exposure to indoor radon. This dissertation examines three issues associated with radon entry into buildings: (1) the influence of a subslab gravel layer and the size of the openings between the soil and the building interior on radon entry; (2) the effect of atmospheric pressure fluctuations on radon entry; and (3) the development and validation of mathematical models which simulate radon and soil-gas entry into houses. Experiments were conducted using two experimental basements to examine the influence of a subslab gravel layer on advective radon entry driven by steady indoor-outdoor pressure differences. These basement structures are identical except that in one the floor slab lies directly on native soil whereas in the other the slab lies on a high-permeability gravel layer. The measurements indicate that a high permeability subslab gravel layer increases the advective radon entry rate into the structure by as much as a factor of 30. The magnitude of the enhancement caused by the subslab gravel layer depends on the area of the openings in the structure floor; the smaller the area of these openings the larger the enhancement in the radon entry rate caused by the subslab gravel layer. A three-dimensional, finite-difference model correctly predicts the effect of a subslab gravel layer and open area configuration on advective radon entry driven by steady indoor-outdoor pressure differences; however, the model underpredicts the absolute entry rate into each structure by a factor of 1.5.

  9. Development of building envelope structures; Udvikling af klimaskaermskonstruktioner

    Energy Technology Data Exchange (ETDEWEB)

    Monefeldt Tommerup, H. [Danmarks Tekniske Univ., Lyngby (Denmark); Munch-Andersen, J. [Statens Byggeforskningsinstitut, Hoersholm (Denmark); Kjaer Esbensen, P. [Danmarks Tekniske Univ., Lyngby (Denmark)

    2000-08-01

    The present report concludes the work concerning the development of building envelope constructions, which can form the basis of new buildings with considerably less heat demand than in the present building regulations. It has been made probable that it is technically possible to build exterior walls with less heat loss than those just complying with the requirements of the current building regulations with no considerable added use of material apart from insulation. In their structure many of the shown constructions resemble types that are used today, while others presuppose that one part of the wall is attached to the other part or possibly to the rafters. Calculations concerning the importance of heat capacity for a 100 m{sup 2} single-family house have been made which confirm that by using heavy rather than light envelope constructions the reduction of the heating requirements is relatively small. Therefore optimisation of the insulation level can be carried out separately on the building components. A method has been developed for the evaluation of the optimum insulation level for the individual building components of the building envelope based on life cycle cost analysis. The method is based on making up the changes in the operational energy costs/ heating-costs and the cost of construction due to a change in the insulation thickness over a 30-year period. The life span of the primary parts of the building envelope is estimated at 100 years. It is assumed that the gross energy consumption that covers the heating requirements and the heat loss (determined by a simple calculation of degree days) changes concurrently with the change in the insulation thickness, which has been proved to be a reasonable approximation. The life cycle cost analysis has been carried out for a test-house of about 100 m{sup 2} and with two different energy price scenarios: 0.60 dkk/kWh (including taxes and VAT) which roughly corresponds to the present energy price level, and 1.20 dkk

  10. Prospects for poor-man's cloaking with low-contrast all-dielectric optical elements

    DEFF Research Database (Denmark)

    Mortensen, Asger; Sigmund, Ole; Breinbjerg, Olav

    2009-01-01

    We discuss the prospects for low-contrast all-dielectric cloaking and offer a simple picture illustrating the basic obstacle for perfect cloaking without materials with an effective double-negative response. However, the same simple picture also gives directions for less perfect designs allowing ......-lens arrays perform in the opposite limit with L l...

  11. Asymmetric Invisibility Cloaking Theory Based on the Concept of Effective Electromagnetic Fields for Photons

    Science.gov (United States)

    Amemiya, Tomo; Taki, Masato; Kanazawa, Toru; Arai, Shigehisa

    2014-03-01

    The asymmetric invisibility cloak is a special cloak with unidirectional transparency; that is, a person in the cloak should not be seen from the outside but should be able to see the outside. Existing theories of designing invisibility cloaks cannot be used for asymmetric cloaking because they are based on the transformation optics that uses Riemannian metric tensor independent of direction. To overcome this problem, we propose introducing directionality into invisibility cloaking. Our theory is based on ``the theory of effective magnetic field for photons'' proposed by Stanford University.[2] To realize asymmetric cloaking, we have extended the Stanford's theory to add the concept of ``effective electric field for photons.'' The effective electric and the magnetic field can be generated using a photonc resonator lattice, which is a kind of metamaterial. The Hamiltonian for photons in these fields has a similar form to that of the Hamiltonian for a charged particle in an electromagnetic field. An incident photon therefore experiences a ``Lorentz-like'' and a ``Coulomb-like'' force and shows asymmetric movement depending of its travelling direction.We show the procedure of designing actual invisibility cloaks using the photonc resonator lattice and confirm their operation with the aid of computer simulation. This work was supported in part by the MEXT; JSPS KAKENHI Grant Numbers #24246061, #24656046, #25420321, #25420322.

  12. Metasurface Cloak Performance Near-by Multiple Line Sources and PEC Cylindrical Objects

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Yatman, William H.; Pehrson, Signe

    2014-01-01

    The performance/robustness of metasurface cloaks to a complex field environment which may represent a realistic scenario of radiating sources is presently reported. Attention is devoted to the cloak operation near-by multiple line sources and multiple perfectly electrically conducting cylinders. ...

  13. Balanced Evaluation of Structural and Environmental Performances in Building Design

    Directory of Open Access Journals (Sweden)

    Marco Lamperti Tornaghi

    2018-03-01

    Full Text Available The design of new buildings, and even more the rehabilitation of existing ones, needs to satisfy modern criteria in terms of energy efficiency and environmental performance, within the context of adequate safety requirements. Tackling all these needs at the same time is cumbersome, as demonstrated by several experiences during recent earthquakes, where the improvement of energy performance vanished by seismic-induced damages. The costs of energy retrofitting must be added to the normal losses caused by the earthquake. Even though the minimum safety requirements are met (no collapse, the damage due to earthquake might be enough to waste the investment made to improve energy efficiency. Since these measures are often facilitated by corresponding incentives, the use of public funding is not cost effective. The application of the existing impact assessment methods is typically performed at the end of the architectural and structural design process. Thus, no real optimisation can be achieved, because a good structural solution could correspond to a poor environmental performance and vice versa. The proposed Sustainable Structural Design method (SSD considers both environmental and structural parameters in the life cycle perspective. The integration of environmental data in the structural performance is the focus of the method. Structural performances are considered in a probabilistic approach, through the introduction of a simplified Performance Based Assessment method. Finally, the SSD method is implemented with a case-study of an office-occupancy building, both for precast and cast-in-situ structural systems, with the aim to find the best solution in terms of sustainability and structural performance for the case at hand.

  14. Experimental verification of free-space singular boundary conditions in an invisibility cloak

    International Nuclear Information System (INIS)

    Wu, Qiannan; Gao, Fei; Song, Zhengyong; Lin, Xiao; Zhang, Youming; Zhang, Baile; Chen, Huanyang

    2016-01-01

    A major issue in invisibility cloaking, which caused intense mathematical discussions in the past few years but still remains physically elusive, is the plausible singular boundary conditions associated with the singular metamaterials at the inner boundary of an invisibility cloak. The perfect cloaking phenomenon, as originally proposed by Pendry et al for electromagnetic waves, cannot be treated as physical before a realistic inner boundary of a cloak is demonstrated. Although a recent demonstration has been done in a waveguide environment, the exotic singular boundary conditions should apply to a general environment as in free space. Here we fabricate a metamaterial surface that exhibits the singular boundary conditions and demonstrate its performance in free space. Particularly, the phase information of waves reflected from this metamaterial surface is explicitly measured, confirming the singular responses of boundary conditions for an invisibility cloak. (paper)

  15. Experimental verification of free-space singular boundary conditions in an invisibility cloak

    Science.gov (United States)

    Wu, Qiannan; Gao, Fei; Song, Zhengyong; Lin, Xiao; Zhang, Youming; Chen, Huanyang; Zhang, Baile

    2016-04-01

    A major issue in invisibility cloaking, which caused intense mathematical discussions in the past few years but still remains physically elusive, is the plausible singular boundary conditions associated with the singular metamaterials at the inner boundary of an invisibility cloak. The perfect cloaking phenomenon, as originally proposed by Pendry et al for electromagnetic waves, cannot be treated as physical before a realistic inner boundary of a cloak is demonstrated. Although a recent demonstration has been done in a waveguide environment, the exotic singular boundary conditions should apply to a general environment as in free space. Here we fabricate a metamaterial surface that exhibits the singular boundary conditions and demonstrate its performance in free space. Particularly, the phase information of waves reflected from this metamaterial surface is explicitly measured, confirming the singular responses of boundary conditions for an invisibility cloak.

  16. A self-assembled three-dimensional cloak in the visible

    KAUST Repository

    Mühlig, Stefan

    2013-08-07

    An invisibility cloak has been designed, realized and characterized. The cloak hides free-standing sub-wavelength three-dimensional objects at the short wavelength edge of the visible spectrum. By a bottom-up approach the cloak was self-assembled around the object. Such fabrication approach constitutes a further important step towards real world applications of cloaking; leaving the realm of curiosity. The cloak and the way it was fabricated opens an avenue for many spectacular nanooptical applications such as non-disturbing sensors and photo-detectors, highly efficient solar cells, or optical nanoantenna arrays with strongly suppressed cross-talk to mention only a few. Our results rely on the successful combination of concepts from various disciplines, i.e. chemistry, material science, and plasmonics. Consequently, this work will stimulate these fields by unraveling new paths for future research.

  17. A self-assembled three-dimensional cloak in the visible

    KAUST Repository

    Mü hlig, Stefan; Cunningham, Alastair; Dintinger, José ; Farhat, Mohamed; Hasan, Shakeeb Bin; Scharf, Toralf; Bü rgi, Thomas; Lederer, Falk; Rockstuhl, Carsten

    2013-01-01

    An invisibility cloak has been designed, realized and characterized. The cloak hides free-standing sub-wavelength three-dimensional objects at the short wavelength edge of the visible spectrum. By a bottom-up approach the cloak was self-assembled around the object. Such fabrication approach constitutes a further important step towards real world applications of cloaking; leaving the realm of curiosity. The cloak and the way it was fabricated opens an avenue for many spectacular nanooptical applications such as non-disturbing sensors and photo-detectors, highly efficient solar cells, or optical nanoantenna arrays with strongly suppressed cross-talk to mention only a few. Our results rely on the successful combination of concepts from various disciplines, i.e. chemistry, material science, and plasmonics. Consequently, this work will stimulate these fields by unraveling new paths for future research.

  18. Toward Accessing Spatial Structure from Building Information Models

    Science.gov (United States)

    Schultz, C.; Bhatt, M.

    2011-08-01

    Data about building designs and layouts is becoming increasingly more readily available. In the near future, service personal (such as maintenance staff or emergency rescue workers) arriving at a building site will have immediate real-time access to enormous amounts of data relating to structural properties, utilities, materials, temperature, and so on. The critical problem for users is the taxing and error prone task of interpreting such a large body of facts in order to extract salient information. This is necessary for comprehending a situation and deciding on a plan of action, and is a particularly serious issue in time-critical and safety-critical activities such as firefighting. Current unifying building models such as the Industry Foundation Classes (IFC), while being comprehensive, do not directly provide data structures that focus on spatial reasoning and spatial modalities that are required for high-level analytical tasks. The aim of the research presented in this paper is to provide computational tools for higher level querying and reasoning that shift the cognitive burden of dealing with enormous amounts of data away from the user. The user can then spend more energy and time in planning and decision making in order to accomplish the tasks at hand. We present an overview of our framework that provides users with an enhanced model of "built-up space". In order to test our approach using realistic design data (in terms of both scale and the nature of the building models) we describe how our system interfaces with IFC, and we conduct timing experiments to determine the practicality of our approach. We discuss general computational approaches for deriving higher-level spatial modalities by focusing on the example of route graphs. Finally, we present a firefighting scenario with alternative route graphs to motivate the application of our framework.

  19. Structural impact response for assessing railway vibration induced on buildings

    Science.gov (United States)

    Kouroussis, Georges; Mouzakis, Harris P.; Vogiatzis, Konstantinos E.

    2018-03-01

    Over the syears, the rapid growth in railway infrastructure has led to numerous environmental challenges. One such significant issue, particularly in urban areas, is ground-borne vibration. A common source of ground-borne vibration is caused by local defects (e.g. rail joints, switches, turnouts, etc.) that generate large amplitude excitations at isolated locations. Modelling these excitation sources is particularly challenging and requires the use of complex and extensive computational efforts. For some situations, the use of experiments and measured data offers a rapid way to estimate the effect of such defects and to evaluate the railway vibration levels using a scoping approach. In this paper, the problem of railway-induced ground vibrations is presented along with experimental studies to assess the ground vibration and ground borne noise levels, with a particular focus on the structural response of sensitive buildings. The behaviour of particular building foundations is evaluated through experimental data collected in Brussels Region, by presenting the expected frequency responses for various types of buildings, taking into account both the soil-structure interaction and the tramway track response. A second study is dedicated to the Athens metro, where transmissibility functions are used to analyse the effect of various Athenian building face to metro network trough comprehensive measurement campaigns. This allows the verification of appropriate vibration mitigation measures. These benchmark applications based on experimental results have been proved to be efficient to treat a complex problem encountered in practice in urban areas, where the urban rail network interacts with important local defects and where the rise of railway ground vibration problems has clearly been identified.

  20. Building

    OpenAIRE

    Seavy, Ryan

    2014-01-01

    Building for concrete is temporary. The building of wood and steel stands against the concrete to give form and then gives way, leaving a trace of its existence behind. Concrete is not a building material. One does not build with concrete. One builds for concrete. MARCH

  1. FRF-based structural damage detection of controlled buildings with podium structures: Experimental investigation

    Science.gov (United States)

    Xu, Y. L.; Huang, Q.; Zhan, S.; Su, Z. Q.; Liu, H. J.

    2014-06-01

    How to use control devices to enhance system identification and damage detection in relation to a structure that requires both vibration control and structural health monitoring is an interesting yet practical topic. In this study, the possibility of using the added stiffness provided by control devices and frequency response functions (FRFs) to detect damage in a building complex was explored experimentally. Scale models of a 12-storey main building and a 3-storey podium structure were built to represent a building complex. Given that the connection between the main building and the podium structure is most susceptible to damage, damage to the building complex was experimentally simulated by changing the connection stiffness. To simulate the added stiffness provided by a semi-active friction damper, a steel circular ring was designed and used to add the related stiffness to the building complex. By varying the connection stiffness using an eccentric wheel excitation system and by adding or not adding the circular ring, eight cases were investigated and eight sets of FRFs were measured. The experimental results were used to detect damage (changes in connection stiffness) using a recently proposed FRF-based damage detection method. The experimental results showed that the FRF-based damage detection method could satisfactorily locate and quantify damage.

  2. Automated structure solution, density modification and model building.

    Science.gov (United States)

    Terwilliger, Thomas C

    2002-11-01

    The approaches that form the basis of automated structure solution in SOLVE and RESOLVE are described. The use of a scoring scheme to convert decision making in macromolecular structure solution to an optimization problem has proven very useful and in many cases a single clear heavy-atom solution can be obtained and used for phasing. Statistical density modification is well suited to an automated approach to structure solution because the method is relatively insensitive to choices of numbers of cycles and solvent content. The detection of non-crystallographic symmetry (NCS) in heavy-atom sites and checking of potential NCS operations against the electron-density map has proven to be a reliable method for identification of NCS in most cases. Automated model building beginning with an FFT-based search for helices and sheets has been successful in automated model building for maps with resolutions as low as 3 A. The entire process can be carried out in a fully automatic fashion in many cases.

  3. Equipment and building structures ageing management for WWER type NPPs

    International Nuclear Information System (INIS)

    Mayboroda, O.

    2001-01-01

    This report presents the working group 'Equipment and building structures ageing management for WWER type NPPs' activities. The analysis of experience in ageing management, recommendations for regulatory guidelines on ageing management, investigation of case studies, definition suitable communication channels among regulators for ageing related data are given. Analyses of water chemistry, inspection data (safety margins criteria), plugging criteria, volume and time of ECT implementation in all WWER countries are presented. The results of Working group activity show that it is advisable to concentrate efforts on: set up the permanent communication channel among regulators, collection of regulatory criteria for WWER type NPP key components based on understanding of ageing mechanisms and data collection

  4. Contaminant deposition building shielding factors for US residential structures

    International Nuclear Information System (INIS)

    Dickson, E D; Hamby, D M; Eckerman, K F

    2015-01-01

    This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario from contaminant deposition on the roof and surrounding surfaces. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations from contaminant deposition on the roof and surrounding ground as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement as well for single-wide manufactured housing-unit. (paper)

  5. Cloud immersion building shielding factors for US residential structures

    International Nuclear Information System (INIS)

    Dickson, E D; Hamby, D M

    2014-01-01

    This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario within a semi-infinite cloud of radioactive material. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement, as well for single-wide manufactured housing-units. (paper)

  6. Contaminant deposition building shielding factors for US residential structures.

    Science.gov (United States)

    Dickson, Elijah; Hamby, David; Eckerman, Keith

    2017-10-10

    This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario from contaminant deposition on the roof and surrounding surfaces. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations from contaminant deposition on the roof and surrounding ground as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement as well for single-wide manufactured housing-unit. © 2017 IOP Publishing Ltd.

  7. Design and analysis of the trapeziform and flat acoustic cloaks with controllable invisibility performance in a quasi-space

    Directory of Open Access Journals (Sweden)

    Jian Zhu

    2015-07-01

    Full Text Available We present the design, implementation and detailed performance analysis for a class of trapeziform and flat acoustic cloaks. An effective large invisible area is obtained compared with the traditional carpet cloak. The cloaks are realized with homogeneous metamaterials which are made of periodic arrangements of subwavelength unit cells composed of steel embedded in air. The microstructures and its effective parameters of the cloaks are determined quickly and precisely in a broadband frequency range by using the effective medium theory and the proposed parameters optimization method. The invisibility capability of the cloaks can be controlled by the variation of the key design parameters and scale factor which are proved to have more influence on the performance in the near field than that in the far field. Different designs are suitable for different application situations. Good cloaking performance demonstrates that such a device can be physically realized with natural materials which will greatly promote the real applications of invisibility cloak.

  8. 30 CFR 57.4530 - Exits for surface buildings and structures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exits for surface buildings and structures. 57... Fire Prevention and Control Installation/construction/maintenance § 57.4530 Exits for surface buildings and structures. Surface buildings or structures in which persons work shall have a sufficient number...

  9. Floor response spectra of buildings with uncertain structural properties

    International Nuclear Information System (INIS)

    Chen, P.C.

    1975-01-01

    All Category I equipment, such as reactors, vessels, and major piping systems of nuclear power plants, is required to withstand earthquake loadings in order to minimize risk of seismic damage. The equipment is designed by using response spectra of the floor on which the equipment is mounted. The floor response spectra are constructed usually from the floor response time histories which are obtained through a deterministic dynamic analysis. This analysis assumes that all structural parameters, such as mass, stiffness, and damping have been calculated precisely, and that the earthquakes are known. However, structural parameters are usually difficult to determine precisely if the structures are massive and/or irregular, such as nuclear containments and its internal structures with foundation soil incorporated into the analysis. Faced with these uncertainties, it has been the practice to broaden the floor response spectra peaks by +-10 percent of the peak frequencies on the basis of conservatism. This approach is based on engineering judgement and does not have an analytical basis to provide a sufficient level of confidence in using these spectra for equipment design. To insure reliable design, it is necessary to know structural response variations due to variations in structural properties. This consideration leads to the treatment of structural properties as random variables and the use of probabilistic methods to predict structural response more accurately. New results on floor response spectra of buildings with uncertain structural properties obtained by determining the probabilistic dynamic response from the deterministic dynamic response and its standard deviation are presented. The resulting probabilistic floor response spectra are compared with those obtained deterministically, and are shown to provide a more reliable method for determining seismic forces

  10. Achieving bifunctional cloak via combination of passive and active schemes

    Science.gov (United States)

    Lan, Chuwen; Bi, Ke; Gao, Zehua; Li, Bo; Zhou, Ji

    2016-11-01

    In this study, a simple and delicate approach to realizing manipulation of multi-physics field simultaneously through combination of passive and active schemes is proposed. In the design, one physical field is manipulated with passive scheme while the other with active scheme. As a proof of this concept, a bifunctional device is designed and fabricated to behave as electric and thermal invisibility cloak simultaneously. It is found that the experimental results are consistent with the simulated ones well, confirming the feasibility of our method. Furthermore, the proposed method could also be extended to other multi-physics fields, which might lead to potential applications in thermal, electric, and acoustic areas.

  11. Horizontal cloaking and vertical reflection by transformation acoustics

    Directory of Open Access Journals (Sweden)

    Min Kyung Lee

    2013-05-01

    Full Text Available This investigation shows that if an acoustic metamaterial bounded by an external rectangle and an internal circular cavity is properly engineered by a set of transformation equations that satisfy certain requirements, it can virtually cloak an object against incoming acoustic waves in one direction and make an incoming wave along the orthogonal direction reflected by an object located inside its inner cavity. The specific transformation equations realizing the metamaterial are suggested and an analysis is carried out to investigate the wave phenomena taking place along the cavity boundary.

  12. Spherical and cylindrical particle resonator as a cloak system

    Science.gov (United States)

    Minin, I. V.; Minin, O. V.; Eremeev, A. I.; Tseplyaev, I. S.

    2018-05-01

    The concept of dielectric spherical or cylindrical particle in resonant mode as a cloak system is offered. In fundamental modes (modes with the smallest volume correspond to |m| = l, and s = 1) the field is concentrated mostly in the equatorial plane and at the surface of the sphere. Thus under resonance modes, such perturbation due to cuboid particle inserted in the spherical or cylindrical particle has almost no effect on the field forming resonance regardless of the value of internal particle material (defect) as long as this material does not cover the region where resonance takes place.

  13. Broadband unidirectional acoustic cloak based on phase gradient metasurfaces with two flat acoustic lenses

    Science.gov (United States)

    Wang, Xiao-Peng; Wan, Le-Le; Chen, Tian-Ning; Song, Ai-Ling; Wang, Fang

    2016-07-01

    Narrow bandwidth and bulky configuration are the main obstacles for the realization and application of invisible cloaks. In this paper, we present an effective method to achieve broadband and thin acoustic cloak by using an acoustic metasurface (AMS). In order to realize this cloak, we use slitted unit cells to design the AMS due to the advantage of less energy loss, broad operation bandwidth, and subwavelength thickness. According to the hyperboloidal phase profile along the AMS, the incident plane waves can be focused at a designed focal spot by the flat lens. Furthermore, broadband acoustic cloak is obtained by combining two identical flat lenses. The incident plane waves are focused at the center point in between of the two lenses by passing through one lens, and then recovered by passing through the other one. However, they cannot reach the cloaked regions in between of the two lenses. The simulation results can verify the non-detectability effect of the acoustic cloak. Our study results provide an available and simple approach to experimentally achieve the acoustic cloak, which can be used in acoustic non-detectability for large objects.

  14. An efficient cost function for the optimization of an n-layered isotropic cloaked cylinder

    International Nuclear Information System (INIS)

    Paul, Jason V; Collins, Peter J; Coutu, Ronald A Jr

    2013-01-01

    In this paper, we present an efficient cost function for optimizing n-layered isotropic cloaked cylinders. Cost function efficiency is achieved by extracting the expression for the angle independent scatterer contribution of an associated Green's function. Therefore, since this cost function is not a function of angle, accounting for every bistatic angle is not necessary and thus more efficient than other cost functions. With this general and efficient cost function, isotropic cloaked cylinders can be optimized for many layers and material parameters. To demonstrate this, optimized cloaked cylinders made of 10, 20 and 30 equal thickness layers are presented for TE and TM incidence. Furthermore, we study the effect layer thickness has on optimized cloaks by optimizing a 10 layer cloaked cylinder over the material parameters and individual layer thicknesses. The optimized material parameters in this effort do not exhibit the dual nature that is evident in the ideal transformation optics design. This indicates that the inevitable field penetration and subsequent PEC boundary condition at the cylinder must be taken into account for an optimal cloaked cylinder design. Furthermore, a more effective cloaked cylinder can be designed by optimizing both layer thickness and material parameters than by additional layers alone. (paper)

  15. Relations between constructive peculiarities and structural behavior in Venice buildings

    Directory of Open Access Journals (Sweden)

    Doglioni, F.

    2012-12-01

    Full Text Available Here we are synthetically describing some constructive peculiarities of Venice civil buildings, analyzing the relation with the features of their structural decay and behavior in the long run. We suppose Venetian buildings, especially those parts which are conceived to suit the lagoon environment, to have undergone an evolution made of some adjustments, which were based on the observation of damages in previous buildings. That is we suppose ancient builders to rely on their awareness of the behavior of structures yet to come, and to be able to forecast it in part. This process brought some building contrivances to perfection, as exclusive and enduring features of Venice, overcoming changes in style and architectural layout, till they grew into essential elements of a whole and adaptable “device”. This writing is meant for a concise interpretation of this device, which is the result of some research works carried out at Venice IUAV University.

    En este texto, se describen sintéticamente algunas peculiaridades de la edificación residencial de Venecia, analizando su relación con el abanico de problemas estructurales que caracterizan el comportamiento estructural del edificio a lo largo del tiempo. Se aventura la hipótesis que las construcciones venecianas y, en particular, algunos de sus detalles, concebidos específicamente para la laguna donde se enclava, han sido objeto de una adaptación evolutiva a través de la observación de los problemas estructurales de los edificios precedentes. Los alarifes venecianos aprendieron a tener en cuenta el comportamiento estructural posterior del edificio, que previeron en cierta medida. Este proceso ha llevado a perfeccionar algunos detalles constructivos exclusivos de Venecia que han perdurado en el tiempo, que han resistido impertérritos a mutaciones de estilo y de configuración arquitectónica, hasta constituir elementos esenciales de un aparato indivisible y adaptable cuya interpretaci

  16. Metafier - a Tool for Annotating and Structuring Building Metadata

    DEFF Research Database (Denmark)

    Holmegaard, Emil; Johansen, Aslak; Kjærgaard, Mikkel Baun

    2017-01-01

    in achieving this goal, but often they work as silos. Improving at scale the energy performance of buildings depends on applications breaking these silos and being portable among buildings. To enable portable building applications, the building instrumentation should be supported by a metadata layer...

  17. Soil-structure interaction in fuel handling building

    International Nuclear Information System (INIS)

    Elaidi, B.M.; Eissa, M.A.

    1998-01-01

    This paper presents an accurate three-dimensional seismic soil-structure interaction analysis for large structures. The method is applied to the fuel building in nuclear power plants. The analysis is performed numerically in the frequency domain and the responses are obtained by inverse Fourier transformation. The size of the structure matrices is reduced by transforming the equation of motion to the modal coordinate system. The soil is simulated as a layered media on top of viscoelastic half space. Soil impedance matrices are calculated from the principles of continuum mechanics and account for soil stiffness and energy dissipation. Effects of embedment on the field equations is incorporated through the scattering matrices or by simply scaling the soil impedance. Finite element methods are used to discretize the concrete foundation for the generation of the soil interaction matrices. Decoupling of the sloshing water in the spent fuel pools and the free-standing spent fuel racks is simulated. The input seismic motions are defined by three artificial time history accelerations. These input motions are generated to match the ground design basis response spectra and the target power spectral density function. The methods described in this paper can handle arbitrary foundation layouts, allows for large structural models, and accurately represents the soil impedance. Time history acceleration responses were subsequently used to generate floor response spectra at applicable damping values. (orig.)

  18. Experimental verification of three-dimensional plasmonic cloaking in free-space

    International Nuclear Information System (INIS)

    Rainwater, D; Kerkhoff, A; Melin, K; Soric, J C; Moreno, G; Alù, A

    2012-01-01

    We report the experimental verification of metamaterial cloaking for a 3D object in free space. We apply the plasmonic cloaking technique, based on scattering cancellation, to suppress microwave scattering from a finite-length dielectric cylinder. We verify that scattering suppression is obtained all around the object in the near- and far-field and for different incidence angles, validating our measurements with analytical results and full-wave simulations. Our near-field and far-field measurements confirm that realistic and robust plasmonic metamaterial cloaks may be realized for elongated 3D objects with moderate transverse cross-section at microwave frequencies. (paper)

  19. Transformation-based spherical cloaks designed by an implicit transformation-independent method: theory and optimization

    International Nuclear Information System (INIS)

    Novitsky, Andrey; Qiu, C-W; Zouhdi, Said

    2009-01-01

    Based on the concept of the cloak generating function, we propose an implicit transformation-independent method for the required parameters of spherical cloaks without knowing the needed coordinate transformation beforehand. A non-ideal discrete model is used to calculate and optimize the total scattering cross-sections of different profiles of the generating function. A bell-shaped quadratic spherical cloak is found to be the best candidate, which is further optimized by controlling the design parameters involved. Such improved invisibility is steady even when the model is highly discretized.

  20. Full three-dimensional isotropic carpet cloak designed by quasi-conformal transformation optics.

    Science.gov (United States)

    Silva, Daniely G; Teixeira, Poliane A; Gabrielli, Lucas H; Junqueira, Mateus A F C; Spadoti, Danilo H

    2017-09-18

    A fully three-dimensional carpet cloak presenting invisibility in all viewing angles is theoretically demonstrated. The design is developed using transformation optics and three-dimensional quasi-conformal mapping. Parametrization strategy and numerical optimization of the coordinate transformation deploying a quasi-Newton method is applied. A discussion about the minimum achievable anisotropy in the 3D transformation optics is presented. The method allows to reduce the anisotropy in the cloak and an isotropic medium could be considered. Numerical simulations confirm the strategy employed enabling the design of an isotropic reflectionless broadband carpet cloak independently of the incident light direction and polarization.

  1. Carpet cloak with graded dielectric metasurface (Presentation Recording)

    Science.gov (United States)

    Hsu, LiYi; Lepetit, Thomas; Kante, Boubacar

    2015-09-01

    We demonstrate a method to hide a Gaussian-shaped bump on a ground plane from an incoming plane wave. In essence, we use a graded metasurface to shape the wavefronts like those of a flat ground plane[1,2].The metasurface provides additional phase to the electromagnetic field to control the reflection angle. To mimic a flat ground plane, the reflection angle is chosen to be equal to the incident angle. The desired phase distribution is calculated based on generalized Snell's laws[3]. We design our metasurface in the microwave range using sub-wavelength dielectric resonators. We verify the design by full-wave time-domain simulations and show that the result matches our theory well. This approach can be applied to hide any object on a ground plane not only at microwave frequencies but also at higher frequencies up to the infrared. 1. Jensen Li and J. B. Pendry, Hiding under the Carpet: A New Strategy for Cloaking. Phys. Rev. Lett. 101, 203901 (2008) 2. Andrea Alu, Mantle cloak: Invisibility induced by a surface. Phys. Rev. B 80, 245115 (2009) 3. Yu N, et al. Light propagation with phase discontinuities: Generalized laws of reflection and refraction. Science 334(6054):333-337 (2011)

  2. Structure of steel reactor building and construction method therefor

    International Nuclear Information System (INIS)

    Yamakawa, Toshikimi.

    1997-01-01

    The building of the present invention contains a reactor pressure vessel, and has double steel plate walls endurable to elevation of inner pressure and keeping airtightness, and shielding concretes are filled between the double steel plate walls. It also has empty double steel plate walls not filled with concretes and has pipelines, vent ducts, wirings and a support structures for attaching them between the double steel plate walls. It is endurable to a great inner pressure satisfactory and keeps airtightness by the two spaced steel plates. It can be greatly reduced in the weight, and can be manufactured efficiently with high quality in a plant by so called module construction, and the dimension of the entire of the reactor building can be reduced. It is constructed in a dock, transported on the sea while having the space between the two steel plate walls as a ballast tanks, placed in the site, and shielding concretes are filled between the double steel plate walls. The term for the construction can be reduced, and the cost for the construction can be saved. (N.H.)

  3. Engineering method to build the composite structure ply database

    Directory of Open Access Journals (Sweden)

    Qinghua Shi

    Full Text Available In this paper, a new method to build a composite ply database with engineering design constraints is proposed. This method has two levels: the core stacking sequence design and the whole stacking sequence design. The core stacking sequences are obtained by the full permutation algorithm considering the ply ratio requirement and the dispersion character which characterizes the dispersion of ply angles. The whole stacking sequences are the combinations of the core stacking sequences. By excluding the ply sequences which do not meet the engineering requirements, the final ply database is obtained. One example with the constraints that the total layer number is 100 and the ply ratio is 30:60:10 is presented to validate the method. This method provides a new way to set up the ply database based on the engineering requirements without adopting intelligent optimization algorithms. Keywords: Composite ply database, VBA program, Structure design, Stacking sequence

  4. Hydraulic behaviour of a representative structural volume for containment buildings

    International Nuclear Information System (INIS)

    Jason, Ludovic; Pijaudier-Cabot, Gilles; Ghavamian, Shahrokh; Huerta, Antonio

    2007-01-01

    For particular structures like containment buildings of nuclear power plants, the study of the hydraulic behaviour is of great concern. These structures are indeed the third barrier used to protect the environment in case of accidents. The evolution of the leaking rate through the porous medium is closely related to the changes in the permeability during the ageing process of the structure. It is thus essential to know the relation between concrete degradation and the transfer property when the consequences of a mechanical loading on the hydraulic behaviour have to be evaluated. A chained approach is designed for this purpose. The mechanical behaviour is described by an elastic plastic damage formulation, where damage is responsible for the softening evolution while plasticity accounts for the development of irreversible strains. The drying process is evaluated according to a non-linear equation of diffusion. From the knowledge of the damage and the degree of saturation, a relation is proposed to calculate the permeability of concrete. Finally, the non-homogeneous distribution of the hydraulic conductivity is included in the hydraulic problem which is in fact the association of the mass balance equation for gas phase and Darcy law. From this methodology, it is shown how an indicator for the hydraulic flows can be deduced

  5. Building alternate protein structures using the elastic network model.

    Science.gov (United States)

    Yang, Qingyi; Sharp, Kim A

    2009-02-15

    We describe a method for efficiently generating ensembles of alternate, all-atom protein structures that (a) differ significantly from the starting structure, (b) have good stereochemistry (bonded geometry), and (c) have good steric properties (absence of atomic overlap). The method uses reconstruction from a series of backbone framework structures that are obtained from a modified elastic network model (ENM) by perturbation along low-frequency normal modes. To ensure good quality backbone frameworks, the single force parameter ENM is modified by introducing two more force parameters to characterize the interaction between the consecutive carbon alphas and those within the same secondary structure domain. The relative stiffness of the three parameters is parameterized to reproduce B-factors, while maintaining good bonded geometry. After parameterization, violations of experimental Calpha-Calpha distances and Calpha-Calpha-Calpha pseudo angles along the backbone are reduced to less than 1%. Simultaneously, the average B-factor correlation coefficient improves to R = 0.77. Two applications illustrate the potential of the approach. (1) 102,051 protein backbones spanning a conformational space of 15 A root mean square deviation were generated from 148 nonredundant proteins in the PDB database, and all-atom models with minimal bonded and nonbonded violations were produced from this ensemble of backbone structures using the SCWRL side chain building program. (2) Improved backbone templates for homology modeling. Fifteen query sequences were each modeled on two targets. For each of the 30 target frameworks, dozens of improved templates could be produced In all cases, improved full atom homology models resulted, of which 50% could be identified blind using the D-Fire statistical potential. (c) 2008 Wiley-Liss, Inc.

  6. Towards smart building structures : adaptive structures in earthquake and wind loading control response – a review

    NARCIS (Netherlands)

    Morales-Beltran, M.; Teuffel, P.M.

    2013-01-01

    This article is a review about applications for non-passive control response of buildings (namely active, hybrid and semi-active systems), wherein the degree of integration between control devices and structural system is explored. The purpose is to establish the current state-of-the-art in the

  7. Green Building Premium Cost Analysis in Indonesia Using Work Breakdown Structure Method

    Science.gov (United States)

    Basten, V.; Latief, Y.; Berawi, M. A.; Riswanto; Muliarto, H.

    2018-03-01

    The concept of green building in the construction industry is indispensable for mitigating environmental issues such as waste, pollution, and carbon emissions. There are some countries that have Green Building rating tools. Indonesia particularly is the country which has Greenship rating tools but the number of Green Building is relatively low. Development of building construction is depended on building investors or owner initiation, so this research is conducted to get the building aspects that have significant effect on the attractiveness using The Green Building Concept. The method in this research is work breakdown structure method that detailing the green building activities. The particular activities will be processed to get the cost elements for the green building achievement that it was targeted to improve better than conventional building. The final result of the study was a very significant work package on green building construction in the city of Indonesia case study.

  8. MUNI Ways and Structures Building Integrated Solar Membrane Project

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Randall

    2014-07-03

    The initial goal of the MUNI Ways and Structures Building Integrated Solar Membrane Installation Project was for the City and County of San Francisco (CCSF) to gain experience using the integrated higher efficiency solar photovoltaic (PV) single-ply membrane product, as it differs from the conventional, low efficiency, thin-film PV products, to determine the feasibility of success of larger deployment. As several of CCSF’s municipal rooftops are constrained with respect to weight restrictions, staff of the Energy Generation Group of the San Francisco Public Utilities Commission (SFPUC) proposed to install a solar PV system using single-ply membrane The installation of the 100 kW (DC-STC) lightweight photo voltaic (PV) system at the MUNI Ways and Structures Center (700 Pennsylvania Ave., San Francisco) is a continuation of the commitment of the City and County of San Francisco (CCSF) to increase the pace of municipal solar development, and serve its municipal facilities with clean renewable energy. The fourteen (14) solar photovoltaic systems that have already been installed at CCSF municipal facilities are assisting in the reduction of fossil-fuel use, and reduction of greenhouse gases from fossil combustion. The MUNI Ways & Structures Center roof has a relatively low weight-bearing capacity (3.25 pounds per square foot) and use of traditional crystalline panels was therefore rejected. Consequently it was decided to use the best available highest efficiency Building-Integrated PV (BIPV) technology, with consideration for reliability and experience of the manufacturer which can meet the low weight-bearing capacity criteria. The original goal of the project was to provide an opportunity to monitor the results of the BIPV technology and compare these results to other City and County of San Francisco installed PV systems. The MUNI Ways and Structures Center was acquired from the Cookson Doors Company, which had run the Center for many decades. The building was

  9. Integral Building Design workshops : a concept to structure communication

    NARCIS (Netherlands)

    Savanovic, P.; Zeiler, W.; Tzou, H.S.; Jalili, N.

    2007-01-01

    Following the developments in (Dutch) building practice, where besides specialist skills a design approach is increasingly being asked, the Building Services chair of the Faculty of Architecture, Building and Planning of Technische Universiteit Eindhoven (TU/e) initiated in academic year 2005/06 a

  10. The scattering of a cylindrical invisibility cloak: reduced parameters and optimization

    International Nuclear Information System (INIS)

    Peng, L; Mortensen, N A; Ran, L

    2011-01-01

    We investigate the scattering of 2D cylindrical invisibility cloaks with simplified constitutive parameters with the assistance of scattering coefficients. We show that the scattering of the cloaks originates not only from the boundary conditions but also from the spatial variation of the component of permittivity/permeability. According to our formulation, we propose some restrictions to the invisibility cloak in order to minimize its scattering after the simplification has taken place. With our theoretical analysis, it is possible to design a simplified cloak using some peculiar composites such as photonic crystals which mimic an effective refractive index landscape rather than offering effective constitutives, meanwhile cancelling the scattering from the inner and outer boundaries.

  11. Schiffer's Conjecture, Interior Transmission Eigenvalues and Invisibility Cloaking: Singular Problem vs. Nonsingular Problem

    OpenAIRE

    Liu, Hongyu

    2012-01-01

    In this note, we present some interesting observations on the Schiffer's conjecture, interior transmission eigenvalue problem and their connections to singular and nonsingular invisibility cloaking problems of acoustic waves.

  12. Theory and potentials of multi-layered plasmonic covers for multi-frequency cloaking

    International Nuclear Information System (INIS)

    Alu, Andrea; Engheta, Nader

    2008-01-01

    We have recently suggested that suitably designed plasmonic layers may cloak a given object simultaneously at multiple frequencies (Alu and Engheta 2008 Phys. Rev. Lett. 100 113901). Here, we extend our theory and fully analyze this possibility, highlighting the potentials of this plasmonic cloaking technique and its fundamental limitations dictated by the passivity and causality of the materials involved. The cloaking mechanism relies on the scattering cancellation properties of plasmonic materials. By exploiting their inherent frequency dispersion, it is possible to reduce the 'visibility' of a given object by several orders of magnitude simultaneously at multiple frequencies, such that any of the particular layers composing the cloak is responsible for noticeable reduction of scattering at each frequency of operation.

  13. Principles of structure building in music, language and animal song

    Science.gov (United States)

    Rohrmeier, Martin; Zuidema, Willem; Wiggins, Geraint A.; Scharff, Constance

    2015-01-01

    Human language, music and a variety of animal vocalizations constitute ways of sonic communication that exhibit remarkable structural complexity. While the complexities of language and possible parallels in animal communication have been discussed intensively, reflections on the complexity of music and animal song, and their comparisons, are underrepresented. In some ways, music and animal songs are more comparable to each other than to language as propositional semantics cannot be used as indicator of communicative success or wellformedness, and notions of grammaticality are less easily defined. This review brings together accounts of the principles of structure building in music and animal song. It relates them to corresponding models in formal language theory, the extended Chomsky hierarchy (CH), and their probabilistic counterparts. We further discuss common misunderstandings and shortcomings concerning the CH and suggest ways to move beyond. We discuss language, music and animal song in the context of their function and motivation and further integrate problems and issues that are less commonly addressed in the context of language, including continuous event spaces, features of sound and timbre, representation of temporality and interactions of multiple parallel feature streams. We discuss these aspects in the light of recent theoretical, cognitive, neuroscientific and modelling research in the domains of music, language and animal song. PMID:25646520

  14. Principles of structure building in music, language and animal song.

    Science.gov (United States)

    Rohrmeier, Martin; Zuidema, Willem; Wiggins, Geraint A; Scharff, Constance

    2015-03-19

    Human language, music and a variety of animal vocalizations constitute ways of sonic communication that exhibit remarkable structural complexity. While the complexities of language and possible parallels in animal communication have been discussed intensively, reflections on the complexity of music and animal song, and their comparisons, are underrepresented. In some ways, music and animal songs are more comparable to each other than to language as propositional semantics cannot be used as indicator of communicative success or wellformedness, and notions of grammaticality are less easily defined. This review brings together accounts of the principles of structure building in music and animal song. It relates them to corresponding models in formal language theory, the extended Chomsky hierarchy (CH), and their probabilistic counterparts. We further discuss common misunderstandings and shortcomings concerning the CH and suggest ways to move beyond. We discuss language, music and animal song in the context of their function and motivation and further integrate problems and issues that are less commonly addressed in the context of language, including continuous event spaces, features of sound and timbre, representation of temporality and interactions of multiple parallel feature streams. We discuss these aspects in the light of recent theoretical, cognitive, neuroscientific and modelling research in the domains of music, language and animal song. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  15. CLASSICAL AREAS OF PHENOMENOLOGY: Material parameter equation for rotating elliptical spherical cloaks

    Science.gov (United States)

    Ma, Hua; Qu, Shao-Bo; Xu, Zhuo; Zhang, Jie-Qiu; Wang, Jia-Fu

    2009-01-01

    By using the coordinate transformation method, we have deduced the material parameter equation for rotating elliptical spherical cloaks and carried out simulation as well. The results indicate that the rotating elliptical spherical cloaking shell, which is made of meta-materials whose permittivity and permeability are governed by the equation deduced in this paper, can achieve perfect invisibility by excluding electromagnetic fields from the internal region without disturbing any external field.

  16. OPTICAL ILLUSION DESIGN BASED ON FOUR CONVEX LENSES SYSTEM AND CLOAKING AREA CHARACTERIZATION

    Directory of Open Access Journals (Sweden)

    I. T. Sugiarto

    2018-01-01

    Full Text Available A set up of optical illusion based on 4f system and characterization of cloaking area have been carried out. The cloaking area is an area where the object is placed on the area as if it disappears from view; the set-up of cloaking area is located at the top of the third lens. The distance between the lens and the cloaking, which is generated from 4f system, depends on the size of the focal point and the size of the lens used. The larger the focal point of the lens used the wider the distance between the lenses and the larger the size of the diameter of the lens, the cloaking range will be increasingly wide, and vice versa. From the experimental results that we obtained that the cloaking area for set up using FL (focusing lens 100, 50, 50 and 100 mm with a diameter of 3.6 cm lens is ± 2 cm, whereas for the set up using lens FL 150, 100, 100 and 150 mm with lens diameter 2.54 cm is ± 1 cm.

  17. Extinction cross-section suppression and active acoustic invisibility cloaking

    Science.gov (United States)

    Mitri, F. G.

    2017-10-01

    Invisibility in its canonical form requires rendering a zero extinction cross-section (or energy efficiency) from an active or a passive object. This work demonstrates the successful theoretical realization of this physical effect for an active cylindrically radiating acoustic body, undergoing periodic axisymmetric harmonic vibrations near a flat rigid boundary. Radiating, amplification and extinction cross-sections of the active source are defined. Assuming monopole and dipole modal oscillations of the circular source, conditions are found where the extinction energy efficiency factor of the active source vanishes, achieving total invisibility with minimal influence of the source size. It also takes positive or negative values, depending on its size and distance from the boundary. Moreover, the amplification energy efficiency factor is negative for the acoustically-active source. These effects also occur for higher-order modal oscillations of the active source. The results find potential applications in the development of acoustic cloaking devices and invisibility.

  18. Extinction cross-section suppression and active acoustic invisibility cloaking

    International Nuclear Information System (INIS)

    Mitri, F G

    2017-01-01

    Invisibility in its canonical form requires rendering a zero extinction cross-section (or energy efficiency) from an active or a passive object. This work demonstrates the successful theoretical realization of this physical effect for an active cylindrically radiating acoustic body, undergoing periodic axisymmetric harmonic vibrations near a flat rigid boundary. Radiating, amplification and extinction cross-sections of the active source are defined. Assuming monopole and dipole modal oscillations of the circular source, conditions are found where the extinction energy efficiency factor of the active source vanishes, achieving total invisibility with minimal influence of the source size. It also takes positive or negative values, depending on its size and distance from the boundary. Moreover, the amplification energy efficiency factor is negative for the acoustically-active source. These effects also occur for higher-order modal oscillations of the active source. The results find potential applications in the development of acoustic cloaking devices and invisibility. (letter)

  19. Tunable Graphene Metasurface Reflectarray for Cloaking, Illusion, and Focusing

    Science.gov (United States)

    Biswas, Sudipta Romen; Gutiérrez, Cristian E.; Nemilentsau, Andrei; Lee, In-Ho; Oh, Sang-Hyun; Avouris, Phaedon; Low, Tony

    2018-03-01

    This paper is a contribution to the Physical Review Applied collection in memory of Mildred S. Dresselhaus. We present a graphene-based metasurface that can be actively tuned between different regimes of operation, such as anomalous beam steering and focusing, cloaking, and illusion optics, by applying electrostatic gating without modifying the geometry of the metasurface. The metasurface is designed by placing graphene ribbons on a dielectric cavity resonator, where interplay between geometric plasmon resonances in the ribbons and Fabry-Perot resonances in the cavity is used to achieve a 2 π phase shift. As a proof of concept, we demonstrate that the wave front of the field reflected from a triangular bump covered by the metasurface can be tuned by applying electric bias so as to resemble that of a bare plane and of a spherical object. Moreover, reflective focusing and the change of the reflection direction for the above mentioned cases are also shown.

  20. Partial elastodynamic cloaking by means of fiber-reinforced composites

    International Nuclear Information System (INIS)

    Olsson, P; Wall, David J N

    2011-01-01

    In this paper, we show that if inextensible fibers are embedded in an elastic material (or the material is by some other means made considerably stiffer in a particular but possibly variable direction), one may obtain equations of motion which are form invariant under certain diffeomorphism, allowing for partial cloaking (or 'illusion optics') schemes in both 2D and 3D. The schemes are valid at all frequencies without requiring any active material properties, and will thus work in the time domain without requiring active materials. While being mathematically exact at all frequencies, the applicability is of course limited to where the continuum approximation holds. Additional limits, set by idealization in the modeling of fibers and core material, are also present. However, contrary to some other approaches, the solution does not require metamaterials with non-scalar mass densities, nor does it require the breaking of the supersymmetry of the elasticity tensor

  1. Partial elastodynamic cloaking by means of fiber-reinforced composites

    Science.gov (United States)

    Olsson, P.; Wall, David J. N.

    2011-04-01

    In this paper, we show that if inextensible fibers are embedded in an elastic material (or the material is by some other means made considerably stiffer in a particular but possibly variable direction), one may obtain equations of motion which are form invariant under certain diffeomorphism, allowing for partial cloaking (or 'illusion optics') schemes in both 2D and 3D. The schemes are valid at all frequencies without requiring any active material properties, and will thus work in the time domain without requiring active materials. While being mathematically exact at all frequencies, the applicability is of course limited to where the continuum approximation holds. Additional limits, set by idealization in the modeling of fibers and core material, are also present. However, contrary to some other approaches, the solution does not require metamaterials with non-scalar mass densities, nor does it require the breaking of the supersymmetry of the elasticity tensor.

  2. Reliability and service life of wood structures and buildings

    OpenAIRE

    Zdeňka Havířová; Pavel Kubů

    2005-01-01

    Service life of constructions and buildings of wood is dependent on temperature and moisture conditions in layers of the building cladding where the wood framework is built in. Temperature/moisture conditions or the corresponding equilibrium moisture content (EMC) of the construction show considerable effects on the functional reliability of the whole building from the viewpoint of mechanical resistance and stability (ER1), energy savings and thermal protection (ER6) and hygiene, health and e...

  3. Structural wood products in onshore buildings at Naval Station Norfolk, 2000.

    Science.gov (United States)

    David B. McKeever

    2003-01-01

    As of December 31, 2000, there were 603 buildings at Naval Station (NAVSTA) Norfolk with a combined floor area of nearly 17.3 million ft2. In one-third of these buildings, structural wood products were used in one or more major structural building applications, utilizing an estimated 11.6 million board feet of lumber, 0.4 million ft2 (3/8-in. basis) of structural...

  4. COMPUTER MODELING OF STRUCTURAL - CONCENTRATION CHARACTERISTICS OF BUILDING COMPOSITE MATERIALS

    Directory of Open Access Journals (Sweden)

    I. I. Zaripova

    2015-09-01

    Full Text Available In the article the computer modeling of structural and concentration characteristics of the building composite material on the basis of the theory of the package. The main provisions of the algorithmon the basis of which it was possible to get the package with a significant number of packaged elements, making it more representative in comparison with existing analogues modeling. We describe the modeled area related areas, the presence of which determines the possibility of a percolation process, which in turn makes it possible to study and management of individual properties of the composite material of construction. As an example of the construction of a composite material is considered concrete that does not exclude the possibility of using algorithms and modeling results of similar studies for composite matrix type (matrix of the same material and distributed in a certain way by volume particles of another substance. Based on modeling results can be manufactured parts and construction elementsfor various purposes with improved technical characteristics (by controlling the concentration composition substance.

  5. Rigidly framed earth retaining structures thermal soil structure interaction of buildings supporting unbalanced lateral earth pressures

    CERN Document Server

    Aboumoussa, Walid

    2014-01-01

    Structures placed on hillsides often present a number of challenges and a limited number of economical choices for site design. An option sometimes employed is to use the building frame as a retaining element, comprising a Rigidly Framed Earth Retaining Structure (RFERS). The relationship between temperature and earth pressure acting on RFERS, is explored in this monograph through a 4.5 year monitoring program of a heavily instrumented in service structure. The data indicated that the coefficient of earth pressure behind the monitored RFERS had a strong linear correlation with temperature. The study also revealed that thermal cycles, rather than lateral earth pressure, were the cause of failure in many structural elements. The book demonstrates that depending on the relative stiffness of the retained soil mass and that of the structural frame, the developed lateral earth pressure, during thermal expansion, can reach magnitudes several times larger than those determined using classical earth pressure theories....

  6. DESIGN PROBLEMS OF THE BUILDINGS FOUNDATIONS AND STRUCTURES CONSTRUCTED IN DENSE URBAN AREAS

    Directory of Open Access Journals (Sweden)

    O. Yu. Prokopov

    2007-10-01

    Full Text Available The urgency of methodical provision of planning of foundations for buildings erected next to existing ones is сonsidered. It is based on studying the causes of extension of deformations of structures in conditions of dense city building system. Some recommendations providing safety of buildings are given.

  7. DESIGN PROBLEMS OF THE BUILDINGS FOUNDATIONS AND STRUCTURES CONSTRUCTED IN DENSE URBAN AREAS

    OpenAIRE

    O. Yu. Prokopov; M. V. Prokopova

    2007-01-01

    The urgency of methodical provision of planning of foundations for buildings erected next to existing ones is сonsidered. It is based on studying the causes of extension of deformations of structures in conditions of dense city building system. Some recommendations providing safety of buildings are given.

  8. Indicators for functional service life of building structures

    NARCIS (Netherlands)

    Blok, R.; Teuffel, P.

    2014-01-01

    The Estimated Service Life, ESL, is of a major influence in many building assessments. The comparison and optimization of design alternatives depend on the accuracy of this ESL. More and more the Functional Service Life rather than the Technical Service Life is decisive in how long a building can be

  9. Industrial robots application in the construction of buildings and structures

    Directory of Open Access Journals (Sweden)

    Verzhbovskiy Gennady

    2017-01-01

    Full Text Available Proposals on the use of modernized industrial robots in the construction of low-rise buildings are formulated. The necessary parameters of such a mechanism are established. The time necessary for building the walls of a two-story house is determined. Features of the robots use on the construction site are described.

  10. Constitutive Parameters of Metamaterial Structures Used for Invisible Cloak Realization

    Science.gov (United States)

    2013-10-01

    Sipus Dario Bojanjac Marko Bosiljevac Fakultet Elektrotechnike I Racunarstva Unska 3 Zagreb 10000 Croatia EOARD Grant 12-2080...Racunarstva Unska 3 Zagreb 10000 Croatia 8. PERFORMING ORGANIZATION REPORT NUMBER N/A 9. SPONSORING/MONITORING AGENCY NAME(S) AND...University of Zagreb Unska 3 Zagreb , HR-10000, Croatia 13 October 2013 Distribution A: Approved for public release; distribution is

  11. Typological diversity of tall buildings and complexes in relation to their functional structure

    Science.gov (United States)

    Generalov, Viktor P.; Generalova, Elena M.; Kalinkina, Nadezhda A.; Zhdanova, Irina V.

    2018-03-01

    The paper focuses on peculiarities of tall buildings and complexes, their typology and its formation in relation to their functional structure. The research is based on the analysis of tall buildings and complexes and identifies the following main functional elements of their formation: residential, administrative (office), hotel elements. The paper also considers the following services as «disseminated» in the space-planning structure: shops, medicine, entertainment, kids and sports facilities, etc., their location in the structure of the total bulk of the building and their impact on typological diversity. Research results include suggestions to add such concepts as «single-function tall buildings» and «mixed-use tall buildings and complexes» into the classification of tall buildings. In addition, if a single-function building or complex performs serving functions, it is proposed to add such concepts as «a residential tall building (complex) with provision of services», «an administrative (public) tall building (complex) with provision of services» into the classification of tall buildings. For mixed-use buildings and complexes the following terms are suggested: «a mixed-use tall building with provision of services», «a mixed-use tall complex with provision of services».

  12. Structural Identification And Seismic Analysis Of An Existing Masonry Building

    International Nuclear Information System (INIS)

    Del Monte, Emanuele; Galano, Luciano; Ortolani, Barbara; Vignoli, Andrea

    2008-01-01

    The paper presents the diagnostic investigation and the seismic analysis performed on an ancient masonry building in Florence. The building has historical interest and is subjected to conservative restrictions. The investigation involves a preliminary phase concerning the research of the historic documents and a second phase of execution of in situ and laboratory tests to detect the mechanical characteristics of the masonry. This investigation was conceived in order to obtain the 'LC2 Knowledge Level' and to perform the non-linear pushover analysis according to the new Italian Standards for seismic upgrading of existing masonry buildings

  13. Structural design of the turbine building of Angra Nuclear Power Station, Unit 1

    International Nuclear Information System (INIS)

    Varella, L.N.; Reis, F.J.C.; Jurkiewicz, W.J.

    1978-01-01

    The Turbine Building of the Angra Nuclear Power Plant, Unit 1, and particularly its structure and structural design are described. The Turbine Building, as far as its structure is concerned, deviates from the standard structure of any turbine building due to the fact that huge ducts are provided in the foundation mat as to accomodate the circulating water system. This aspect and the fact that the building is founded upon a very deep strata of compacted and controlled fill, makes out of the building structure 'a concrete ship floating in the sea of sand', and by the same reason presents by itself an interesting structure, worth to be known to all engineers involved in design of power plants. This pape, suplemented by a few slides shown during presentation of the paper at the conference, covers the subject mainly from the designers' point of view. (Author)

  14. Cooling of the Building Structure by Night-time Ventilation

    DEFF Research Database (Denmark)

    Artmann, Nikolai

    is essential for effective night cooling, and thus a sufficient amount of thermal mass is needed in the building. In order to assess the impact of different parameters, such as slab thickness, material properties and the surface heat transfer, the dynamic heat storage capacity of building elements...... was quantified based on an analytical solution of one-dimensional heat conduction in a slab with convective boundary condition. The potential of increasing thermal mass by using phase change materials (PCM) was also estimated. The results show a significant impact of the heat transfer coefficient on heat storage...... a building energy simulation program (HELIOS), and the effect of different parameters such as building construction, heat gains, air change rates, heat transfer coefficients and climatic conditions on the number of overheating degree hours (operative room temperature >26 °C) was evaluated. Besides climatic...

  15. Reliability and service life of wood structures and buildings

    Directory of Open Access Journals (Sweden)

    Zdeňka Havířová

    2005-01-01

    Full Text Available Service life of constructions and buildings of wood is dependent on temperature and moisture conditions in layers of the building cladding where the wood framework is built in. Temperature/moisture conditions or the corresponding equilibrium moisture content (EMC of the construction show considerable effects on the functional reliability of the whole building from the viewpoint of mechanical resistance and stability (ER1, energy savings and thermal protection (ER6 and hygiene, health and environment protection (ER3. To ensure the reliability of constructions and buildings for the period of their supposed service life a more profound analysis of constructions is necessary from the aspect of a global thermal/technical evaluation.

  16. Method for VAWT Placement on a Complex Building Structure

    Science.gov (United States)

    2013-06-01

    Dec. 2013. [5] F. Balduzzi, A. Bianchini, E. Carnevale, L Ferrari, S. Magnani, “Feasibility analysis of a Darrieus vertical-axis wind turbine ... turbines used to power the cooling system. A simulation of Building 216, which is the planned site of the cooling system, was performed. A wind flow...analysis found that optimum placement of the wind turbines is at the front of the south end of the building. The method for placing the wind turbines is

  17. Experimental building with new types of building envelope structures. Part 1: Structures/systems. Building system: Brick walls; Forsoegshus med nye typer klimaskaermskonstruktioner. Del 1: Konstruktioner/systemer - Byggesystem: Fuldmuret

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    The house described in this report is one of several experimental houses forming part of the project 'Experimental buildings with new types of building envelope structures'. One purpose of the project is to demonstrate that it is possible to build typical single-family houses with an energy consumption that meets expected increased building regulations. Furthermore, it is important that the houses can be made securely as regards construction technology and within reasonable financial limits. Thus, the purpose is also to contribute to strengthen the development of improved building envelope structures. Another purpose is to carry out detailed measurements of energy consumption in order to validate thermal performance of future building envelope structures. The report describes the constructive design and energy systems of the house plus heat loss calculations and expected energy consumption. (BA)

  18. Verification of the local structural response of building structures in the anchorage areas of heavy components

    International Nuclear Information System (INIS)

    Krutzik, N.J.; Tropp, R.

    1993-01-01

    In both nuclear and non-nuclear areas of power plants, sections of structures, parts of systems and components are attached to walls and floors by means of anchor plates with bolts, anchor sleeves and bolts and through bolts arranged either in groups or individually. In order to simplify the determination of the transfered vibrations induced by external events (e.g. earthquake, aircraft crash), it is normally assumed that the nodal point between component and concrete possesses rigid body characteristics and the building structure (walls, floors) is also inflexible in the anchorage area. In the course of the parametric studies performed, the nonlinear effects on the anchorage area of a component (in this case an anchor plate and concrete slab) were calculated and the effect of these on the actual vibration behavior and the local structural responses of the building structure at the place of installation of heavy components were investigated. The investigations performed reveal that by taking into account the local behaviour in the anchoring point, it is possible to reduce the dynamic response considerably. More detailed examination of the influence of additional parameters (especially of the geometry of the anchor plates and anchor bolts and their material characteristics) will require further investigations aimed at establishing the characteristics of typical anchor plates. (orig.)

  19. Design and analysis of gradient index metamaterial-based cloak with wide bandwidth and physically realizable material parameters

    Science.gov (United States)

    Bisht, Mahesh Singh; Rajput, Archana; Srivastava, Kumar Vaibhav

    2018-04-01

    A cloak based on gradient index metamaterial (GIM) is proposed. Here, the GIM is used, for conversion of propagating waves into surface waves and vice versa, to get the cloaking effect. The cloak is made of metamaterial consisting of four supercells with each supercell possessing the linear spatial variation of permittivity and permeability. The spatial variation of material parameters in supercells allows the conversion of propagating waves into surface waves and vice versa, hence results in reduction of electromagnetic signature of the object. To facilitate the practical implementation of the cloak, continuous spatial variation of permittivity and/or permeability, in each supercell, is discretized into seven segments and it is shown that there is not much deviation in cloaking performance of discretized cloak as compared to its continuous counterpart. The crucial advantage, of the proposed cloaks, is that the material parameters are isotropic and in physically realizable range. Furthermore, the proposed cloaks have been shown to possess bandwidth of the order of 190% which is a significantly improved performance compared to the recently published literature.

  20. Cooling of the Building Structure by Night-time Ventilation

    DEFF Research Database (Denmark)

    Artmann, Nikolai

    In modern, extensively glazed office buildings, due to high solar and internal loads and increased comfort expectations, air conditioning is increasingly applied even in moderate and cold climates, like in Central and Northern Europe. Particularly in these cases, night-time ventilation is often......, without considering any building-specific parameters. A method for quantifying the climatic cooling potential (CCP) was developed based on degree-hours of the difference between building and external air temperature. Applying this method to climatic data of 259 stations shows very high night cooling...... potential over the whole of Northern Europe and still significant potential in Central, Eastern and even some regions of Southern Europe. However, due to the inherent stochastic properties of weather patterns, series of warmer nights can occur at some locations, where passive cooling by night...

  1. Soil Structure Interaction Effect on High Rise and Low Rise Buildings

    OpenAIRE

    Divya Pathak; PAresh H. SHAH

    2000-01-01

    Effect of supporting soil on the response of structure has been analyzed in the present study. A low rise (G+ 5 storey) and a high rise (G+12 storey) building has been taken for the analysis. For both type of buildings, the response of building with and without consideration of soil structure interaction effect has been compared.Without interaction case is the case in which ends of the structure are assumed to be fixed while in interaction case, structure is assumed to be...

  2. Adoption of Smart Structures for Prevention of Health Hazards in Buildings

    Science.gov (United States)

    Oke, Ayodeji; Aigbavboa, Clinton; Ngema, Wiseman

    2017-11-01

    The importance of building quality to the health and well-being of occupants and surrounding neighbors cannot be overemphasized. Smart structures were construed to proffer solution to various issues of sustainable development including social factors that is concerned with health and safety of people. Based on existing literature materials on building quality, smart structures and general aspect of sustainable developments, this study examined the benefits of smart structures in the prevention of various health issues in infrastructural buildings, which has been a concern for stakeholders in the architecture, engineering and construction industry. The criterion for indoor environmental quality was adopted and various health and bodily issues related to building quality were explained. The adoption of smart structure concept will help to manage physical, chemical, biological and psychological factors of building with a view to enhancing better quality of life of occupants.

  3. Evaluation of structural systems in precast concrete buildings by ...

    African Journals Online (AJOL)

    In general, the precast concrete is the type of concrete that constructing, casting and curing in the standard factory conditions with high quality and then it will be transported with proper equipments and then it will be installed in the final position. In fact, the precast concrete buildings are the combined of several types of ...

  4. Clearance of building structures for conventional non-nuclear reuse

    International Nuclear Information System (INIS)

    Buss, K.; Boehringer, S.

    1998-01-01

    At the example of a fuel assembly plant the strategy of control measurements on building surfaces, which shall be conventionally reused after their clearance, is regarded. Based on the given clearance levels the used measuring methods, especially with regard of possibly covered or intruded uranium contamination, are shown. The possibility of using the in-situ-γ-spectroscopy is discussed. (orig.) [de

  5. Assessment matrix for timber structures : basis for standardized building checks

    NARCIS (Netherlands)

    Abels, M.

    2011-01-01

    How can futurily be secured enabling people to enter stable and utilisable buildings permanently and everywhere for them to stay, live and work safely? In order to avoid catastrophies like the collapse of the Bad Reichenhall ice pavillion (Germany) in 2006, a method of evaluation (= assessment

  6. Vibrations in a Multi-Storey Lightweight Building Structure

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard; Kirkegaard, Poul Henning

    2013-01-01

    This paper provides a quantification of the changes in vibration level that can be expected in a lightweight multi-storey wooden building due to reduced connection stiffness or added nonstructural mass. Firstly, the impact of changes in the floor-to-wall connections is examined. Secondly, a study...

  7. Finding the displacement of wood structure in heritage building by 3D laser scanner

    Science.gov (United States)

    Lee, M. C.; Tsai, Y. L.; Wang, R. Z.; Lin, M. L.

    2015-08-01

    Heritage buildings are highly prone to long term damage from the microclimate, scourge and vandalism, which can result in damaged materials, structures, painting and cultural heritage items. This study will focus on finding the displacement of wood structural members through the use of a 3D laser scanner and the 4D concept of time. The results will compare the scans from different periods to find the difference (if any) in the structural member position. Wood structures usually consist of numerous wood members connected to form the structure. However, these members can be damaged in various ways such as physical mechanisms, chemical reactions, and biological corrosion. When damage to the wood structure occurs, the structural displacement can be affected, and if affected severely, can lead to a building collapse. Monitoring of the structural displacement is the best way to discover damage immediately and to preserve the heritage building. However, the Cultural Heritage Preservation Law in Taiwan prohibits the installation of monitoring instruments (e.g strain gauge, accelerometer) in historic structures (heritage buildings). Scanning the wood structure with 3D lasers is the most non-intrusive method and quickly achieves displacement through visualization. The displacement scan results can be compared with different periods and different members to analyze the severity of damage. Once the 3D scanner is installed, the whole building is scanned, and point clouds created to build the visual building model. The structural displacement can be checked via the building model and the differences are measured between each member to find the high risk damaged areas or members with large displacement. Early detection of structural damage is the most effective way means of preservation.

  8. Direct Linear System Identification Method for Multistory Three-dimensional Building Structure with General Eccentricity

    OpenAIRE

    Shintani, Kenichirou; Yoshitomi, Shinta; Takewaki, Izuru

    2017-01-01

    A method of physical parameter system identification (SI) is proposed here for three-dimensional (3D) building structures with in-plane rigid floors in which the stiffness and damping coefficients of each structural frame in the 3D building structure are identified from the measured floor horizontal accelerations. A batch processing least-squares estimation method for many discrete time domain measured data is proposed for the direct identification of the stiffness and damping coefficients of...

  9. Structural and compositional features of high-rise buildings: experimental design in Yekaterinburg

    Science.gov (United States)

    Yankovskaya, Yulia; Lobanov, Yuriy; Temnov, Vladimir

    2018-03-01

    The study looks at the specifics of high-rise development in Yekaterinburg. High-rise buildings are considered in the context of their historical development, structural features, compositional and imaginative design techniques. Experience of Yekaterinburg architects in experimental design is considered and analyzed. Main issues and prospects of high-rise development within the Yekaterinburg structure are studied. The most interesting and significant conceptual approaches to the structural and compositional arrangement of high-rise buildings are discussed.

  10. Active electromagnetic invisibility cloaking and radiation force cancellation

    Science.gov (United States)

    Mitri, F. G.

    2018-03-01

    This investigation shows that an active emitting electromagnetic (EM) Dirichlet source (i.e., with axial polarization of the electric field) in a homogeneous non-dissipative/non-absorptive medium placed near a perfectly conducting boundary can render total invisibility (i.e. zero extinction cross-section or efficiency) in addition to a radiation force cancellation on its surface. Based upon the Poynting theorem, the mathematical expression for the extinction, radiation and amplification cross-sections (or efficiencies) are derived using the partial-wave series expansion method in cylindrical coordinates. Moreover, the analysis is extended to compute the self-induced EM radiation force on the active source, resulting from the waves reflected by the boundary. The numerical results predict the generation of a zero extinction efficiency, achieving total invisibility, in addition to a radiation force cancellation which depend on the source size, the distance from the boundary and the associated EM mode order of the active source. Furthermore, an attractive EM pushing force on the active source directed toward the boundary or a repulsive pulling one pointing away from it can arise accordingly. The numerical predictions and computational results find potential applications in the design and development of EM cloaking devices, invisibility and stealth technologies.

  11. Infrared Cloaking, Stealth, and the Second Law of Thermodynamics

    Directory of Open Access Journals (Sweden)

    Daniel P. Sheehan

    2012-10-01

    Full Text Available Infrared signature management (IRSM has been a primary aeronautical concern for over 50 years. Most strategies and technologies are limited by the second law of thermodynamics. In this article, IRSM is considered in light of theoretical developments over the last 15 years that have put the absolute status of the second law into doubt and that might open the door to a new class of broadband IR stealth and cloaking techniques. Following a brief overview of IRSM and its current thermodynamic limitations, theoretical and experimental challenges to the second law are reviewed. One proposal is treated in detail: a high power density, solid-state power source to convert thermal energy into electrical or chemical energy. Next, second-law based infrared signature management (SL-IRSM strategies are considered for two representative military scenarios: an underground installation and a SL-based jet engine. It is found that SL-IRSM could be technologically disruptive across the full spectrum of IRSM modalities, including camouflage, surveillance, night vision, target acquisition, tracking, and homing.

  12. ANALYSIS OF SUFFICIENCY OF THE BEARING CAPACITY OF BUILDING STRUCTURES OF OPERATING SITES OF MAIN BUILDINGS OF THERMAL POWER PLANTS

    Directory of Open Access Journals (Sweden)

    Alekseeva Ekaterina Leonidovna

    2012-10-01

    Full Text Available Upon examination of eleven main buildings of power plants, analysis of defects and damages of building structures was performed. Thereafter, the damageability of principal bearing structures of main buildings of thermal plants was analyzed. It was identified that the fastest growing defects and damages were concentrated in the structures of operating sites. The research of the rate of development of the most frequent damages and defects made it possible to conclude that internal corrosion of the reinforcing steel was the most dangerous defect, as far as the reinforced concrete elements of operating sites were concerned. Methods of mathematical statistics were applied to identify the reinforcing steel development pattern inside reinforced concrete elements of floors of operating sites. It was identified that the probability of corrosion of reinforced concrete elements of operating sites was distributed in accordance with the demonstrative law. Based on these data, calculation of strength of reinforced concrete slabs and metal beams was performed in terms of their regular sections, given the natural loads and the realistic condition of structures. As a result, dependence between the bearing capacity reserve ratio and the corrosion development pattern was identified for reinforced concrete slabs and metal beams of operating sites. In order to analyze the sufficiency of the bearing capacity of building structures of operating sites in relation to their time in commission, equations were derived to identify the nature of dependence between the sufficiency of the bearing capacity of reinforced concrete slabs and metal beams of the operating sites and their time in commission.

  13. Synthesis of vibration control and health monitoring of building structures under unknown excitation

    International Nuclear Information System (INIS)

    He, Jia; Huang, Qin; Xu, You-Lin

    2014-01-01

    The vibration control and health monitoring of building structures have been actively investigated in recent years but often treated separately according to the primary objective pursued. In this study, a time-domain integrated vibration control and health monitoring approach is proposed based on the extended Kalman filter (EKF) for identifying the physical parameters of the controlled building structures without the knowledge of the external excitation. The physical parameters and state vectors of the building structure are then estimated and used for the determination of the control force for the purpose of the vibration attenuation. The interaction between the health monitoring and vibration control is revealed and assessed. The feasibility and reliability of the proposed approach is numerically demonstrated via a five-story shear building structure equipped with magneto-rheological (MR) dampers. Two types of excitations are considered: (1) the EI-Centro ground excitation underneath of the building and (2) a swept-frequency excitation applied on the top floor of the building. Results show that the structural parameters as well as the unknown dynamic loadings could be identified accurately; and, at the same time, the structural vibration is significantly reduced in the building structure. (paper)

  14. Verification of the local structural response of building structures in the anchorage areas of heavy components

    International Nuclear Information System (INIS)

    Krutzik, N.J.; Tropp, R.

    1989-01-01

    In conventional dynamic structural analyses for determining dynamic system response for various locations at which components are installed inside the structures it is common practice (in order to simplify analytical effort) to assume that the anchorage (anchor plate, anchor bolts or throughbolts, concrete and reinforcement in the area of bound) has rigid body characteristics and that the building structure itself does not display any local response of its own. The influence of the stiffness of the anchor plate as well anchor bolts and its stress level on the dynamic response is also neglected. For a large number of anchoring systems, especially for all those components and systems having only a small mass, this assumption is certainly appropriate. At some locations, particularly at points where heavy components are anchored or when loading input has been increased, this can lead to local loading of the anchor system as well as of the building structure well into the nonlinear range. Often, verification of capability to accommodate these loads is not possible without changing the wall thicknesses or increasing the percentage of reinforcement. Since the presence of linear or nonlinear effects can be expected to result in energy dissipation (increase in damping capacity and also a change in the stiffness of the coupled system) it must be assumed that the dynamic response between the theoretical coupling point A and the real connection point B of the component on the anchor plate can be considerably altered. Some changes of the dynamic response in the connection point B have to be expected generally even in cases of linear-elastic loading of the anchorage. Using typical anchoring systems as an example, the influence of consideration of nonlinear effects in the anchorage area of a typical anchor plate on the dynamic response as well as the conservatism of conventional analytical approaches are investigated

  15. Structural safety of HDR reactor building during large scale vibration tests

    International Nuclear Information System (INIS)

    Stangenberg, F.; Zinn, R.

    1985-01-01

    In the second phase of the HDR investigations, a high shaker excitation of the building is planned using a large shaker which will be located on the operating floor and will be brought up to speed in a balanced condition and then unbalanced and decoupled from the drive system. With decreasing speed the shaker comes in resonance with the building frequencies and its energy is transferred to the building. In this paper the structural safety of the reactor building during the projected shaker tests is analysed. Dynamic response calculations with coupling between building and shaker by simultaneously integrating the equilibrium equations of both building and shaker are presented. The resulting building stresses, soil pressures etc. are compared with allowable values. (orig.)

  16. Realization of a thermal cloak-concentrator using a metamaterial transformer.

    Science.gov (United States)

    Liu, Ding-Peng; Chen, Po-Jung; Huang, Hsin-Haou

    2018-02-06

    By combining rotating squares with auxetic properties, we developed a metamaterial transformer capable of realizing metamaterials with tunable functionalities. We investigated the use of a metamaterial transformer-based thermal cloak-concentrator that can change from a cloak to a concentrator when the device configuration is transformed. We established that the proposed dual-functional metamaterial can either thermally protect a region (cloak) or focus heat flux in a small region (concentrator). The dual functionality was verified by finite element simulations and validated by experiments with a specimen composed of copper, epoxy, and rotating squares. This work provides an effective and efficient method for controlling the gradient of heat, in addition to providing a reference for other thermal metamaterials to possess such controllable functionalities by adapting the concept of a metamaterial transformer.

  17. Cloaks and antiobject-independent illusion optics based on illusion media

    Science.gov (United States)

    Li, Zhou; Zang, XiaoFei; Cai, Bin; Shi, Cheng; Zhu, YiMing

    2013-11-01

    Based on the transformation optics, we propose a new strategy of illusion media consisting of homogeneous and anisotropic materials. By utilizing the illusion media, invisible cloak is theoretically realized, in which objects covered with the illusion media could not be detected. The cloak here allows neither the propagation of light around the concealed region nor compensates the scattering field of object outside the media. What the cloak does is to shift the region into another place where outside the trace of light, so that objects in that region can disappear. Another application of the illusion media is to create the antiobject-independent illusion optics which means that two objects appear to be like some other objects of our choice. Finite element simulations for two-dimensional cases have been performed to prove these ideas.

  18. VIBRATION OF FRAME BUILDING STRUCTURES CAUSED BY UNDERGROUND TRAINS

    Directory of Open Access Journals (Sweden)

    P. V. Аliavdin

    2011-01-01

    Full Text Available The paper contains investigations on element vibration of a real residential 9-storeyed reinforced-concrete frame building induced by train movement in the shallow subway. A design model for a problem on propagation of bending waves within the limits of the typical fragment of a skeleton is presented in the paper. The steady state vibrations of a column and reinforced-concrete slab induced by an excited force which is equivalent to the impact of the subway trains have been investigated in the paper. The problem has been solved numerically on the basis of the ANSYS FEA program. Numerical results have been compared with an approximate analytical solution and data on full-scale experiment. A prediction technique for vibration propagation in the designed buildings is offered in the paper. 

  19. Object-Based Dense Matching Method for Maintaining Structure Characteristics of Linear Buildings.

    Science.gov (United States)

    Su, Nan; Yan, Yiming; Qiu, Mingjie; Zhao, Chunhui; Wang, Liguo

    2018-03-29

    In this paper, we proposed a novel object-based dense matching method specially for the high-precision disparity map of building objects in urban areas, which can maintain accurate object structure characteristics. The proposed framework mainly includes three stages. Firstly, an improved edge line extraction method is proposed for the edge segments to fit closely to building outlines. Secondly, a fusion method is proposed for the outlines under the constraint of straight lines, which can maintain the building structural attribute with parallel or vertical edges, which is very useful for the dense matching method. Finally, we proposed an edge constraint and outline compensation (ECAOC) dense matching method to maintain building object structural characteristics in the disparity map. In the proposed method, the improved edge lines are used to optimize matching search scope and matching template window, and the high-precision building outlines are used to compensate the shape feature of building objects. Our method can greatly increase the matching accuracy of building objects in urban areas, especially at building edges. For the outline extraction experiments, our fusion method verifies the superiority and robustness on panchromatic images of different satellites and different resolutions. For the dense matching experiments, our ECOAC method shows great advantages for matching accuracy of building objects in urban areas compared with three other methods.

  20. Object-Based Dense Matching Method for Maintaining Structure Characteristics of Linear Buildings

    Directory of Open Access Journals (Sweden)

    Nan Su

    2018-03-01

    Full Text Available In this paper, we proposed a novel object-based dense matching method specially for the high-precision disparity map of building objects in urban areas, which can maintain accurate object structure characteristics. The proposed framework mainly includes three stages. Firstly, an improved edge line extraction method is proposed for the edge segments to fit closely to building outlines. Secondly, a fusion method is proposed for the outlines under the constraint of straight lines, which can maintain the building structural attribute with parallel or vertical edges, which is very useful for the dense matching method. Finally, we proposed an edge constraint and outline compensation (ECAOC dense matching method to maintain building object structural characteristics in the disparity map. In the proposed method, the improved edge lines are used to optimize matching search scope and matching template window, and the high-precision building outlines are used to compensate the shape feature of building objects. Our method can greatly increase the matching accuracy of building objects in urban areas, especially at building edges. For the outline extraction experiments, our fusion method verifies the superiority and robustness on panchromatic images of different satellites and different resolutions. For the dense matching experiments, our ECOAC method shows great advantages for matching accuracy of building objects in urban areas compared with three other methods.

  1. Building Points - Montana Structures/Addresses Framework - Web Service

    Data.gov (United States)

    NSGIC State | GIS Inventory — Map service for the Montana Structures MSDI Framework. The service will only display at scales of 1:100,000 or larger. Structures are grouped into general categories...

  2. Building Footprints - MO 2012 Perry Structure Footprints (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Staff at the Geographic Resources Center placed categorized polygons on all roofed structures larger than standard domicile structure size at a scale of 1:2000 using...

  3. Building Footprints - MO 2012 Cape Girardeau Structure Footprints (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Staff at the Geographic Resources Center placed categorized polygons on all roofed structures larger than standard domicile structure size at a scale of 1:2000 using...

  4. Building Footprints - MO 2012 St. Genevieve Structure Footprints (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Staff at the Geographic Resources Center placed categorized polygons on all roofed structures larger than standard domicile structure size at a scale of 1:2000 using...

  5. Building Footprints - MO 2012 Madison Structure Footprints (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Staff at the Geographic Resources Center placed categorized polygons on all roofed structures larger than standard domicile structure size at a scale of 1:2000 using...

  6. Building Footprints - MO 2012 Bollinger Structure Footprints (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Staff at the Geographic Resources Center placed categorized polygons on all roofed structures larger than standard domicile structure size at a scale of 1:2000 using...

  7. Building Footprints - MO 2012 Iron Structure Footprints (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Staff at the Geographic Resources Center placed categorized polygons on all roofed structures larger than standard domicile structure size at a scale of 1:2000 using...

  8. Constructive systems, load-bearing and enclosing structures of high-rise buildings

    Science.gov (United States)

    Anatol'evna Korol', Elena; Olegovna Kustikova, Yuliya

    2018-03-01

    As the height of the building increases, loads on load-carrying structures increase dramatically, and as a result of the development of high-rise construction, several structural systems of such buildings have been developed: frame, frame-frame, cross-wall, barrel, box-type, box-to-wall ("pipe in pipe", "Trumpet in the farm"), etc. In turn, the barrel systems have their own versions: cantilever support of the ceilings on the trunk, suspension of the outer part of the overlap to the upper carrying console "hanging house" or its support by means of the walls on the lower bearing cantilever, intermediate position of the supporting cantilevers in height to the floor, from a part of floors. The object of the study are the structural solutions of high-rise buildings. The subject of the study is the layout of structural schemes of high-rise buildings, taking into account the main parameters - altitude (height), natural climatic conditions of construction, materials of structural elements and their physical and mechanical characteristics. The purpose of the study is to identify the features and systematization of structural systems of high-rise buildings and the corresponding structural elements. The results of the research make it possible, at the stage of making design decisions, to establish rational parameters for the correspondence between the structural systems of high-rise buildings and their individual elements.

  9. An approach to separating the levels of hierarchical structure building in language and mathematics.

    Science.gov (United States)

    Makuuchi, Michiru; Bahlmann, Jörg; Friederici, Angela D

    2012-07-19

    We aimed to dissociate two levels of hierarchical structure building in language and mathematics, namely 'first-level' (the build-up of hierarchical structure with externally given elements) and 'second-level' (the build-up of hierarchical structure with internally represented elements produced by first-level processes). Using functional magnetic resonance imaging, we investigated these processes in three domains: sentence comprehension, arithmetic calculation (using Reverse Polish notation, which gives two operands followed by an operator) and a working memory control task. All tasks required the build-up of hierarchical structures at the first- and second-level, resulting in a similar computational hierarchy across language and mathematics, as well as in a working memory control task. Using a novel method that estimates the difference in the integration cost for conditions of different trial durations, we found an anterior-to-posterior functional organization in the prefrontal cortex, according to the level of hierarchy. Common to all domains, the ventral premotor cortex (PMv) supports first-level hierarchy building, while the dorsal pars opercularis (POd) subserves second-level hierarchy building, with lower activation for language compared with the other two tasks. These results suggest that the POd and the PMv support domain-general mechanisms for hierarchical structure building, with the POd being uniquely efficient for language.

  10. Ethical Guidelines for Structural Interventions to Small-Scale Historic Stone Masonry Buildings.

    Science.gov (United States)

    Hurol, Yonca; Yüceer, Hülya; Başarır, Hacer

    2015-12-01

    Structural interventions to historic stone masonry buildings require that both structural and heritage values be considered simultaneously. The absence of one of these value systems in implementation can be regarded as an unethical professional action. The research objective of this article is to prepare a guideline for ensuring ethical structural interventions to small-scale stone historic masonry buildings in the conservation areas of Northern Cyprus. The methodology covers an analysis of internationally accepted conservation documents and national laws related to the conservation of historic buildings, an analysis of building codes, especially Turkish building codes, which have been used in Northern Cyprus, and an analysis of the structural interventions introduced to a significant historic building in a semi-intact state in the walled city of Famagusta. This guideline covers issues related to whether buildings are intact or ruined, the presence of earthquake risk, the types of structural decisions in an architectural conservation project, and the values to consider during the decision making phase.

  11. Power systems and electromagnetic safety in of powerful utility buildings and structures

    Directory of Open Access Journals (Sweden)

    О.І. Запорожець

    2008-01-01

    Full Text Available  Researching of origin terms of electromagnetic contaminations from the unbalanced currents and leak currents in the industrial networks of electric supply of structures and buildings saturated energy.

  12. Reactor building with internal structure of which the movements are independent of those of the general raft and process for building these internal structures

    International Nuclear Information System (INIS)

    Hista, J.C.

    1982-01-01

    This reactor building includes a containment enclosure for the internal structures composed of a slab wedged on its periphery against the containment enclosure gusset and resting on the general raft by means of a peripheral bearing ring, a compressible layer being provided between the general raft and the slab [fr

  13. Composite structures of steel and concrete beams, slabs, columns, and frames for buildings

    CERN Document Server

    Johnson, R P

    2008-01-01

    This book sets out the basic principles of composite construction with reference to beams, slabs, columns and frames, and their applications to building structures. It deals with the problems likely to arise in the design of composite members in buildings, and relates basic theory to the design approach of Eurocodes 2, 3 and 4.The new edition is based for the first time on the finalised Eurocode for steel/concrete composite structures.

  14. Design automation of load-bearing arched structures of roofs of tall buildings

    Science.gov (United States)

    Kulikov, Vladimir

    2018-03-01

    The article considers aspects of the possible use of arched roofs in the construction of skyscrapers. Tall buildings experience large load from various environmental factors. Skyscrapers are subject to various and complex types of deformation of its structural elements. The paper discusses issues related to the aerodynamics of various structural elements of tall buildings. The technique of solving systems of equations state method of Simpson. The article describes the optimization of geometric parameters of bearing elements of the arched roofs of skyscrapers.

  15. Probabilistic Seismic Performance Model for Tunnel Form Concrete Building Structures

    Directory of Open Access Journals (Sweden)

    S. Bahram Beheshti Aval

    2016-12-01

    Full Text Available Despite widespread construction of mass-production houses with tunnel form structural system across the world, unfortunately no special seismic code is published for design of this type of construction. Through a literature survey, only a few studies are about the seismic behavior of this type of structural system. Thus based on reasonable numerical results, the seismic performance of structures constructed with this technique considering the effective factors on structural behavior is highly noteworthy in a seismic code development process. In addition, due to newness of this system and observed damages in past earthquakes, and especially random nature of future earthquakes, the importance of probabilistic approach and necessity of developing fragility curves in a next generation Performance Based Earthquake Engineering (PBEE frame work are important. In this study, the seismic behavior of 2, 5 and 10 story tunnel form structures with a regular plan is examined. First, the performance levels of these structures under the design earthquake (return period of 475 years with time history analysis and pushover method are assessed, and then through incremental dynamic analysis, fragility curves are extracted for different levels of damage in walls and spandrels. The results indicated that the case study structures have high capacity and strength and show appropriate seismic performance. Moreover, all three structures subjected were in immediate occupancy performance level.

  16. From intuition to statistics in building subsurface structural models

    Science.gov (United States)

    Brandenburg, J.P.; Alpak, F.O.; Naruk, S.; Solum, J.

    2011-01-01

    Experts associated with the oil and gas exploration industry suggest that combining forward trishear models with stochastic global optimization algorithms allows a quantitative assessment of the uncertainty associated with a given structural model. The methodology is applied to incompletely imaged structures related to deepwater hydrocarbon reservoirs and results are compared to prior manual palinspastic restorations and borehole data. This methodology is also useful for extending structural interpretations into other areas of limited resolution, such as subsalt in addition to extrapolating existing data into seismic data gaps. This technique can be used for rapid reservoir appraisal and potentially have other applications for seismic processing, well planning, and borehole stability analysis.

  17. Building bridges between cellular and molecular structural biology.

    Science.gov (United States)

    Patwardhan, Ardan; Brandt, Robert; Butcher, Sarah J; Collinson, Lucy; Gault, David; Grünewald, Kay; Hecksel, Corey; Huiskonen, Juha T; Iudin, Andrii; Jones, Martin L; Korir, Paul K; Koster, Abraham J; Lagerstedt, Ingvar; Lawson, Catherine L; Mastronarde, David; McCormick, Matthew; Parkinson, Helen; Rosenthal, Peter B; Saalfeld, Stephan; Saibil, Helen R; Sarntivijai, Sirarat; Solanes Valero, Irene; Subramaniam, Sriram; Swedlow, Jason R; Tudose, Ilinca; Winn, Martyn; Kleywegt, Gerard J

    2017-07-06

    The integration of cellular and molecular structural data is key to understanding the function of macromolecular assemblies and complexes in their in vivo context. Here we report on the outcomes of a workshop that discussed how to integrate structural data from a range of public archives. The workshop identified two main priorities: the development of tools and file formats to support segmentation (that is, the decomposition of a three-dimensional volume into regions that can be associated with defined objects), and the development of tools to support the annotation of biological structures.

  18. probabilistic approach to structural appraisal of a building during

    African Journals Online (AJOL)

    ES Obe

    predict the reliability of concrete in a structure under construction, a case study ... target reliability index value of 3.7 for concrete for safety class 1 BKR[1] and less than ..... Control. Cube strength. Grade 15. 15. 17.56. 2.69. 15.33. Normal. Design mix. * fa = 0.33 × 15 = 5.10N/mm2. 2. Ranganathan, R. (1999). Structural Relia-.

  19. Probabilistic Approach to Structural Appraisal of a Building During ...

    African Journals Online (AJOL)

    The design strength of concrete in the structure (grade of concrete) is obtained from schmidt hammer test. The concrete in the structure gave a safety index value of 2.83 which is less than the target reliability index value of 3.7 for concrete for safety class 1 BKR[1] and less than the target reliability index of 4.5 for slabs, 4.9 for ...

  20. Mesh joinery: a method for building fabricable structures

    OpenAIRE

    Cignoni, Paolo; Pietroni, Nico; Malomo, Luigi; Scopigno, Roberto

    2015-01-01

    Mesh joinery is an innovative method to produce illustrative shape approximations suitable for fabrication. Mesh joinery is capable of producing complex fabricable structures in an efficient and visually pleasing manner. We represent an input geometry as a set of planar pieces arranged to compose a rigid structure by exploiting an efficient slit mechanism. Since slices are planar, a standard 2D cutting system is sufficient to fabricate them.

  1. Space-planning and structural solutions of low-rise buildings: Optimal selection methods

    Science.gov (United States)

    Gusakova, Natalya; Minaev, Nikolay; Filushina, Kristina; Dobrynina, Olga; Gusakov, Alexander

    2017-11-01

    The present study is devoted to elaboration of methodology used to select appropriately the space-planning and structural solutions in low-rise buildings. Objective of the study is working out the system of criteria influencing the selection of space-planning and structural solutions which are most suitable for low-rise buildings and structures. Application of the defined criteria in practice aim to enhance the efficiency of capital investments, energy and resource saving, create comfortable conditions for the population considering climatic zoning of the construction site. Developments of the project can be applied while implementing investment-construction projects of low-rise housing at different kinds of territories based on the local building materials. The system of criteria influencing the optimal selection of space-planning and structural solutions of low-rise buildings has been developed. Methodological basis has been also elaborated to assess optimal selection of space-planning and structural solutions of low-rise buildings satisfying the requirements of energy-efficiency, comfort and safety, and economical efficiency. Elaborated methodology enables to intensify the processes of low-rise construction development for different types of territories taking into account climatic zoning of the construction site. Stimulation of low-rise construction processes should be based on the system of approaches which are scientifically justified; thus it allows enhancing energy efficiency, comfort, safety and economical effectiveness of low-rise buildings.

  2. Probabilistic Assessment of Structural Seismic Damage for Buildings in Mid-America

    International Nuclear Information System (INIS)

    Bai, Jong-Wha; Hueste, Mary Beth D.; Gardoni, Paolo

    2008-01-01

    This paper provides an approach to conduct a probabilistic assessment of structural damage due to seismic events with an application to typical building structures in Mid-America. The developed methodology includes modified damage state classifications based on the ATC-13 and ATC-38 damage states and the ATC-38 database of building damage. Damage factors are assigned to each damage state to quantify structural damage as a percentage of structural replacement cost. To account for the inherent uncertainties, these factors are expressed as random variables with a Beta distribution. A set of fragility curves, quantifying the structural vulnerability of a building, is mapped onto the developed methodology to determine the expected structural damage. The total structural damage factor for a given seismic intensity is then calculated using a probabilistic approach. Prediction and confidence bands are also constructed to account for the prevailing uncertainties. The expected seismic structural damage is assessed for a typical building structure in the Mid-America region using the developed methodology. The developed methodology provides a transparent procedure, where the structural damage factors can be updated as additional seismic damage data becomes available

  3. RANDOM FUNCTIONS AND INTERVAL METHOD FOR PREDICTING THE RESIDUAL RESOURCE OF BUILDING STRUCTURES

    Directory of Open Access Journals (Sweden)

    Shmelev Gennadiy Dmitrievich

    2017-11-01

    Full Text Available Subject: possibility of using random functions and interval prediction method for estimating the residual life of building structures in the currently used buildings. Research objectives: coordination of ranges of values to develop predictions and random functions that characterize the processes being predicted. Materials and methods: when performing this research, the method of random functions and the method of interval prediction were used. Results: in the course of this work, the basic properties of random functions, including the properties of families of random functions, are studied. The coordination of time-varying impacts and loads on building structures is considered from the viewpoint of their influence on structures and representation of the structures’ behavior in the form of random functions. Several models of random functions are proposed for predicting individual parameters of structures. For each of the proposed models, its scope of application is defined. The article notes that the considered approach of forecasting has been used many times at various sites. In addition, the available results allowed the authors to develop a methodology for assessing the technical condition and residual life of building structures for the currently used facilities. Conclusions: we studied the possibility of using random functions and processes for the purposes of forecasting the residual service lives of structures in buildings and engineering constructions. We considered the possibility of using an interval forecasting approach to estimate changes in defining parameters of building structures and their technical condition. A comprehensive technique for forecasting the residual life of building structures using the interval approach is proposed.

  4. Developing Dynamic Digital Image Correlation Technique to Monitor Structural Damage of Old Buildings under External Excitation

    Directory of Open Access Journals (Sweden)

    Ming-Hsiang Shih

    2014-01-01

    Full Text Available The capacity of buildings to resist external excitation is an important factor to consider for the structural design of buildings. When subject to external excitation, a building may suffer a certain degree of damages, and its residual capacity to resist external excitation cannot be evaluated. In this research, dynamic digital image correlation method combined with parameter evaluation available in system identification is used to evaluate the structural capacity to resist external excitation. The results reveal possible building latent safety problems so that timely structural reinforcement or dismantling of the building can be initiated to alleviate further damages. The results of experiments using the proposed method conform to the results obtained using the conventional method, but this method is more convenient and rapid than the latter in the subsequent procedure of data processing. If only the frequency change is used, the damages suffered by the building can be detected, but the damage location is not revealed. The interstory drift mode shape (IDMS based on the characteristic of story drift has higher sensitivity than the approximate story damage index (ADSI method based on modal frequency and vibration type; however, both indices can be used to determine the degree and location of building damages.

  5. Toolbox for super-structured and super-structure free multi-disciplinary building spatial design optimisation

    NARCIS (Netherlands)

    Boonstra, S.; van der Blom, K.; Hofmeyer, H.; Emmerich, M.T.M.; van Schijndel, A.W.M.; de Wilde, P.

    2018-01-01

    Multi-disciplinary optimisation of building spatial designs is characterised by large solution spaces. Here two approaches are introduced, one being super-structured and the other super-structure free. Both are different in nature and perform differently for large solution spaces and each requires

  6. Aluminium Structures in Building and Civil Engineering Applications

    NARCIS (Netherlands)

    Soetens, F.

    2010-01-01

    Structural applications of aluminium are considered in this paper. Although the discussion is mainly devoted to Europe, the paper also refers, where possible, to developments in other parts of the world. The problems faced by a designer in creating an optimum design are described, followed by a

  7. 3D engineered fiberboard : a new structural building product

    Science.gov (United States)

    John F. Hunt; Jerrold E. Winandy

    2002-01-01

    To help meet the need for sustainable forest management tools, the USDA Forest Products Laboratory is developing an economically viable process to produce three-dimensional structural fibreboard products that can utilize a wide range of lignocellulosic fibres contained in the forest undergrowth and in underutilized timber. This will encourage the public and private...

  8. Amino Acid Molecular Units: Building Primary and Secondary Protein Structures

    Directory of Open Access Journals (Sweden)

    Aparecido R. Silva

    2008-05-01

    Full Text Available In order to guarantee the learning quality and suitable knowledge  use  about structural biology, it is fundamental to  exist, since the beginning of  students’ formation, the possibility of clear visualization of biomolecule structures. Nevertheless, the didactic books can only bring  schematic  drawings; even more elaborated figures and graphic computation  do not permit the necessary interaction.  The representation of three-dimensional molecular structures with ludic models, built with representative units, have supplied to the students and teachers a successfully experience to  visualize such structures and correlate them to the real molecules.  The design and applicability of the representative units were discussed with researchers and teachers before mould implementation.  In this stage  it  will be presented the  developed  kit  containing the  representative  plastic parts of the main amino acids.  The kit can demonstrate the interaction among the amino acids  functional groups  (represented by colors, shapes,  sizes and  the peptidic bonds between them  facilitating the assembly and visuali zation of the primary and secondary protein structure.  The models were designed for  Ca,  amino,  carboxyl groups  and  hydrogen. The  lateral chains have  well defined models that represent their geometrical shape.  The completed kit set  will be presented in this meeting (patent requested.  In the last phase of the project will be realized  an effective evaluation  of the kit  as a facilitative didactic tool of the teaching/learning process in the Structural Molecular Biology area.

  9. LIFE-CYCLE COST MODEL AND DESIGN OPTIMIZATION OF BASE ISOLATED BUILDING STRUCTURES

    Directory of Open Access Journals (Sweden)

    Chara C. Mitropoulou

    2016-11-01

    Full Text Available Design of economic structures adequately resistant to withstand during their service life, without catastrophic failures, all possible loading conditions and to absorb the induced seismic energy in a controlled fashion, has been the subject of intensive research so far. Modern buildings usually contain extremely sensitive and costly equipment that are vital in business, commerce, education and/or health care. The building contents frequently are more valuable than the buildings them-selves. Furthermore, hospitals, communication and emergency centres, police and fire stations must be operational when needed most: immediately after an earthquake. Conventional con-struction can cause very high floor accelerations in stiff buildings and large interstorey drifts in flexible structures. These two factors cause difficulties in insuring the safety of both building and its contents. For this reason base-isolated structures are considered as an efficient alternative design practice to the conventional fixed-base one. In this study a systematic assessment of op-timized fixed and base-isolated reinforced concrete buildings is presented in terms of their initial and total cost taking into account the life-cycle cost of the structures.

  10. The importance of building construction materials relative to other factors affecting structure survival during wildfire

    Science.gov (United States)

    Syphard, Alexandra D.; Brennan, Teresa J.; Keeley, Jon E.

    2017-01-01

    Structure loss to wildfire is a serious problem in wildland-urban interface areas across the world. Laboratory experiments suggest that fire-resistant building construction and design could be important for reducing structure destruction, but these need to be evaluated under real wildfire conditions, especially relative to other factors. Using empirical data from destroyed and surviving structures from large wildfires in southern California, we evaluated the relative importance of building construction and structure age compared to other local and landscape-scale variables associated with structure survival. The local-scale analysis showed that window preparation was especially important but, in general, creating defensible space adjacent to the home was as important as building construction. At the landscape scale, structure density and structure age were the two most important factors affecting structure survival, but there was a significant interaction between them. That is, young structure age was most important in higher-density areas where structure survival overall was more likely. On the other hand, newer-construction structures were less likely to survive wildfires at lower density. Here, appropriate defensible space near the structure and accessibility to major roads were important factors. In conclusion, community safety is a multivariate problem that will require a comprehensive solution involving land use planning, fire-safe construction, and property maintenance.

  11. Structural transformation of the machine-building enterprises: management approaches

    OpenAIRE

    Obydiennova, T.

    2014-01-01

    The article considers the «classical» approach to the issues of enterprise management: process, system, situational, concrete, functional, resource, factorial approach. Outlines the definitions of each of the approaches to the management of the enterprise, as well as advantages and disadvantages. The author suggests the schematic image of the aspects of the system approach and its application; a scheme of contents resource and functional approaches. For research on the structural transformati...

  12. Automatic Generation of Structural Building Descriptions from 3D Point Cloud Scans

    DEFF Research Database (Denmark)

    Ochmann, Sebastian; Vock, Richard; Wessel, Raoul

    2013-01-01

    We present a new method for automatic semantic structuring of 3D point clouds representing buildings. In contrast to existing approaches which either target the outside appearance like the facade structure or rather low-level geometric structures, we focus on the building’s interior using indoor...... scans to derive high-level architectural entities like rooms and doors. Starting with a registered 3D point cloud, we probabilistically model the affiliation of each measured point to a certain room in the building. We solve the resulting clustering problem using an iterative algorithm that relies...

  13. Forecasting ofuseful life of the structures of a production building during operation

    Directory of Open Access Journals (Sweden)

    Pshenichkina Valeriya

    2017-01-01

    Full Text Available The article presents a probabilistic concept of practical evaluation of the individual resource of structures of industrial buildings and structures in operation. The results of calculation of a monolithic reinforced concrete overpass for safety and durability are given. The quantitative values of the resource are obtained for a given security of operability.

  14. The assessment of fire safety of cast iron structures in historical buildings: Theory and practice

    NARCIS (Netherlands)

    Twilt, L.; Hunen, M. van

    2000-01-01

    The assessment of structural fire safety of cast iron structures in historical buildings is difficult because the available information on the fire behaviour is limited, whilst the fire design assumptions (if any) often are not well docu-mented. A complicating factor with regard to protective

  15. Dynamic Analysis of AP1000 Shield Building Considering Fluid and Structure Interaction Effects

    Directory of Open Access Journals (Sweden)

    Qiang Xu

    2016-02-01

    Full Text Available The shield building of AP1000 was designed to protect the steel containment vessel of the nuclear reactor. Therefore, the safety and integrity must be ensured during the plant life in any conditions such as an earthquake. The aim of this paper is to study the effect of water in the water tank on the response of the AP1000 shield building when subjected to three-dimensional seismic ground acceleration. The smoothed particle hydrodynamics method (SPH and finite element method (FEM coupling method is used to numerically simulate the fluid and structure interaction (FSI between water in the water tank and the AP1000 shield building. Then the grid convergence of FEM and SPH for the AP1000 shield building is analyzed. Next the modal analysis of the AP1000 shield building with various water levels (WLs in the water tank is taken. Meanwhile, the pressure due to sloshing and oscillation of the water in the gravity drain water tank is studied. The influences of the height of water in the water tank on the time history of acceleration of the AP1000 shield building are discussed, as well as the distributions of amplification, acceleration, displacement, and stresses of the AP1000 shield building. Research on the relationship between the WLs in the water tank and the response spectrums of the structure are also taken. The results show that the high WL in the water tank can limit the vibration of the AP1000 shield building and can more efficiently dissipate the kinetic energy of the AP1000 shield building by fluid-structure interaction.

  16. Building a Data Store with the Dynamic Structure

    Directory of Open Access Journals (Sweden)

    Yu. N. Artamonov

    2016-01-01

    Full Text Available This article presents the analysis of approaches to data warehouse construction based on relational and NoSQL solutions and lists the limitations of the relational approach to data mining. The contradiction between data presentation in the real subject domain and the model of data presentation in the relational and NoSQL approaches is revealed. The revealed contradiction is related to the temporality of the values of individual data attributes, the variability of the composition of these attributes, and structure of connections between them. A new logical model of the data warehouse with dynamic structure is proposed. The model is based on the concept of the object as a container for properties storage. Each property of the object includes the property name and two property values without reference and with reference, that are relevant at a given time. The reference property value points to an object whose name is interpreted as the value of the property at a given time. A formal description of the model with allocation of the necessary functionality to manipulate objects and their properties (selectors, predicates, constructors is given and the necessary control structures are introduced. Substantiation of the proposed model, called an OP-model is given on the basis of compliance with the logical ER data model. It is proved that any ER data model can be implemented in the OP-model. At the same time, the advantages of the OP-model are indicated, they are associated with the possibility of changing connections between entities due to changes in the reference value at a particular time. The potential for scalability of data warehouse due to the unique identification of each object is noted. 

  17. Demonstration of an ultralow profile cloak for scattering suppression of a finite-length rod in free space

    International Nuclear Information System (INIS)

    Soric, J C; Chen, P Y; Alù, A; Kerkhoff, A; Rainwater, D; Melin, K

    2013-01-01

    We present the first experimental realization and verification of a three-dimensional stand-alone mantle cloak designed to suppress the total scattering of a finite-length dielectric rod of moderate cross-section. Mantle cloaking has been proposed to realize ultralow-profile conformal covers that may achieve substantial camouflage, transparency and high-performance non-invasive near-field sensing. Here, we realize and verify a mantle cloak for radio-waves. We report an extensive campaign of far- and near-field free-space measurements demonstrating that conformal cloaks can indeed produce strong scattering suppression in all directions and over a relatively broad bandwidth of operation. (paper)

  18. Darlington GS vacuum building - internal structures and foundation

    International Nuclear Information System (INIS)

    Huterer, J.; Brown, D.G.; Yanchula, S.

    1985-01-01

    This paper describes the evolution of the internal structure from initial concept to final design. Fundamental changes to the original configuration were precipitated by the action of large seismic forces acting on a top-heavy configuration. Prestressing was eliminated in deference to high humidity. Aspects of the elevated water tank's peripheral support beam are discussed vis-a-vis an adjacent slipforming operation, and practical construction limitations on steel placement. Also reviewed are the shortening of peripheral columns due to shrinkage and creep, and considerations of crack control for purposes of water-tightness. The authors justify the choice of stainless steel for fabrication of the siphon system's riser pipes. The foundation slab must resist the combined effects of vacuum pressure, hydrostatic uplift, and the seismic reactions of the internal structure and perimeter wall. The dependency of a key foundation component, the gallery roof slab, on the dome tendon layout is high-lighted; and aspects of its constructability are reviewed in light of congestion of vertical tendon anchorages, and of reinforcement. The design of the air-tight slab liner is reviewed, attention focusing on weld design under vacuum and accident temperature loads; on corrosion protection; and on the related construction access bulkhead - its ASME requirements and fabrication tolerances. (orig.)

  19. Scientific Support of Construction of Unique Buildings and Structures and Facilities of Increased Danger

    Science.gov (United States)

    Alekhin, V. N.; Antipin, A. A.; Gorodilov, S. N.

    2017-11-01

    A range of works on scientific support for the construction of unique buildings and the structures and facilities of increased danger, such as airport facilities, long-span and high-rise buildings is being implemented at the department “Computer Aided Design in Civil Engineering” of Ural Federal University. The scope of work includes: numerical simulation of wind and snow loads, analysis of progressive collapse and seismic impacts, verification of design solutions. The results of wind, snow loads and progressive collapse of airport buildings in the cities of Orenburg, Rostov-on-Don and Perm are considered in the article.

  20. Building integrated PV for commercial and institutional structures, a sourcebook for architects

    Energy Technology Data Exchange (ETDEWEB)

    Eiffert, P.; Kiss, G.

    2000-02-14

    This sourcebook on building-integrated photovoltaics (BIPV) is intended for architects and designers interested in learning more about today's sustainable solar buildings. The booklet includes 16 design briefs describing actual structures; they illustrate how electricity-generating BIPV products (such as special roofing systems, vertical-wall systems, skylights, and awnings, all of which contain PV cells, modules, and films) can be integrated successfully into many different kinds of buildings. It also contains basic information about BIPV technologies, an overview of US product development activities and development programs, descriptions of major software design tools, and a bibliography.

  1. Calculation methods of Structure-Soil-Structure Interaction (3SI) for embedded buildings: Application to NUPEC tests

    International Nuclear Information System (INIS)

    Clouteau, D.; Broc, D.; Devesa, G.; Guyonvarh, V.; Massin, P.

    2012-01-01

    This work aims at improving and validating methods coupling Finite Element (FE) and Boundary Element (BE) Methods in the context of Soil-Structure Interaction (SSI) and Structure-Soil-Structure Interaction (3SI) tests performed by NUPEC on mock-up structures built on an unmade ground. Several cases have been tested: single and juxtaposed buildings, shallow and embedded foundations, with various loading conditions: forced and natural seismic loadings. The numerical simulations of forced vibration tests are in good agreement with the results of the NUPEC experiments in the case of two embedded buildings either in terms of amplitude and resonance. The numerical simulation of seismic response tests by FEM and BEM allows for a proper choice of the 'reference point' where the computed and the experimental displacements coincide. A parametric analysis of Structure-Soil-Structure Interaction carried out by the FEM has allowed to determine the influence of some parameters on SSI. Most of them like the position of the building in the excavation, the direction of the load, the quality of the contact between the sidewalls of the buildings and the soil for embedded foundations, do not show to have a strong influence on the dynamic system behaviour, which is mainly governed by the stiffness of the first soil layer. As far as 3SI is concerned, this paper shows that when the cross interaction has a small effect on the building response in the case of surface foundations, it has a strong influence in the case of embedded foundations with an important decrease of the response at the top of the buildings. (authors)

  2. SEISMIC EVALUATION OF EXISTING MID-RISE REINFORCED CONCRETE BUILDINGS ACCORDING TO SPECIFICATION FOR BUILDING STRUCTURES TO BE BUILT IN DISASTER AREAS

    Directory of Open Access Journals (Sweden)

    Mehmet İNEL

    2007-01-01

    Full Text Available Over the past several decades, Turkey has been hit by devastating earthquakes and remarkable number of reinforced concrete buildings has been damaged in the high seismicity regions of our country. The aim of this study is to evaluate the seismic performance of the mid-rise reinforced concrete buildings that are major part of building stock of our earthquake-prone country, according to recent Turkish Earthquake Code. 4- and 7-story buildings were selected to represent mid-rise building stock. After determining the structural parameters, each building was subjected to pushover analysis and the capacity curves were obtained. Earthquake performance of each building was determined in the light of their capacity curves according to the recent Turkish Earthquake Code.

  3. Revised-Confirmatory Survey Report for Portions of the Auxiliary Building Structural Surfaces and Turbine Building Embedded Piping, Rancho Seco Nuclear Generating Station, Herald, California

    International Nuclear Information System (INIS)

    W. C. Adams

    2007-01-01

    During the period of October 15 and 18, 2007, ORISE performed confirmatory radiological survey activities which included beta and gamma structural surface scans and beta activity direct measurements within the Auxiliary Building, beta or gamma scans within Turbine Building embedded piping, beta activity determinations within Turbine Building Drain 3-1-27, and gamma scans and the collection of a soil sample from the clay soils adjacent to the Lower Mixing Box

  4. Structural integrity analysis of an Ignalina nuclear power plant building subjected to an airplane crash

    International Nuclear Information System (INIS)

    Dundulis, Gintautas; Kulak, Ronald F.; Marchertas, Algirdas; Uspuras, Eugenijus

    2007-01-01

    Recent terrorist attacks using commandeered commercial airliners on civil structures have raised the issue of the ability of nuclear power plants to survive the consequences of an airliner crash. The structural integrity analysis due to the effects of an aircraft crash on an Ignalina nuclear power plant (INPP) accident localization system (ALS) building is the subject of this paper. A combination of the finite element method and empirical relationships were used for the analysis. A global structural integrity analysis was performed for a portion of the ALS building using the dynamic loading from an aircraft crash impact model. The local effects caused by impact of the aircraft's engine on the building wall were evaluated independently by using an empirical formula. The results from the crash analysis of a twin engine commercial aircraft show that the impacted reinforced concrete wall of the ALS building will not have through-the-wall concrete failure, and the reinforcement will not fail. Strain-rate effects were found to delay the onset of cracking. Therefore, the structural integrity of the impacted wall of the INPP ALS building will be maintained during the crash event studied

  5. Base Isolation for Seismic Retrofitting of a Multiple Building Structure: Design, Construction, and Assessment

    Directory of Open Access Journals (Sweden)

    Massimiliano Ferraioli

    2017-01-01

    Full Text Available The paper deals with the seismic retrofit of a multiple building structure belonging to the Hospital Centre of Avellino (Italy. At first, the paper presents the preliminary investigations, the in situ measurements and laboratory tests, and the seismic assessment of the existing fixed-base structures. Having studied different strategies, base isolation proved to be the more appropriate, also for the possibility offered by the geometry of the building to easily create an isolation interface at the ground level. The paper presents the design project, the construction process, and the details of the isolation intervention. Some specific issues of base isolation for seismic retrofitting of multiple building structures were lightened. Finally, the seismic assessment of the base-isolated building was carried out. The seismic response was evaluated through nonlinear time-history analysis, using the well-known Bouc-Wen model as the constitutive law of the isolation bearings. For reliable dynamic analyses, a suite of natural accelerograms compatible with acceleration spectra of Italian Code was first selected and then applied along both horizontal directions. The results were finally used to address some of the critical issues of the seismic response of the base-isolated multiple building structure: accidental torsional effects and potential poundings during strong earthquakes.

  6. Structural integrity analysis of an Ignalina nuclear power plant building subjected to an airplane crash

    Energy Technology Data Exchange (ETDEWEB)

    Dundulis, Gintautas [Laboratory of Nuclear Installation Safety, Lithuanian Energy Institute, 3 Breslaujos, 44403 Kaunas-35 (Lithuania)]. E-mail: gintas@isag.lei.lt; Kulak, Ronald F. [RFK Engineering Mechanics Consultants (United States); Marchertas, Algirdas [Northern Illinois University (United States); Uspuras, Eugenijus [Laboratory of Nuclear Installation Safety, Lithuanian Energy Institute, 3 Breslaujos, 44403 Kaunas-35 (Lithuania)

    2007-08-15

    Recent terrorist attacks using commandeered commercial airliners on civil structures have raised the issue of the ability of nuclear power plants to survive the consequences of an airliner crash. The structural integrity analysis due to the effects of an aircraft crash on an Ignalina nuclear power plant (INPP) accident localization system (ALS) building is the subject of this paper. A combination of the finite element method and empirical relationships were used for the analysis. A global structural integrity analysis was performed for a portion of the ALS building using the dynamic loading from an aircraft crash impact model. The local effects caused by impact of the aircraft's engine on the building wall were evaluated independently by using an empirical formula. The results from the crash analysis of a twin engine commercial aircraft show that the impacted reinforced concrete wall of the ALS building will not have through-the-wall concrete failure, and the reinforcement will not fail. Strain-rate effects were found to delay the onset of cracking. Therefore, the structural integrity of the impacted wall of the INPP ALS building will be maintained during the crash event studied.

  7. Behaviour of AR glass fibre for building structural applications

    Directory of Open Access Journals (Sweden)

    Miravete, A.

    2005-12-01

    Full Text Available The AR glass reinforcement fibres were designed to resist the alkalis from the concrete. This is the main reason for its utilisation as a short-fibre-reinforcement of mortar and concrete for the last decades. Originally, the AR glass fibre sizing was not compatible with synthetic resins, so that this type of reinforcement was applied exclusively to mortar and concrete matrices. Recently, due to the developments of sizing, which are compatible with synthetic resins, the AR- glass fibres may be used as reinforcement of organic matrix composite materials, broadening the range of structural applications. The mechanical properties of AR glass fibre and organic matrix composite materials will be studied in this paper. First, the behaviour of this material under stress corrosion will be analysed. Their mass loss will be compared to E, C, and boron free glass fibres. Second, an experimental study dealing with 3P test bending and short beam ofAR glass fibre/polyester will de described with the goal of obtaining their Young modulus and tensile and interlaminar shear strengths. Finally, these experimental results will be compared to E glass fibre/polyester and several conclusions about their structural applications will be drawn.

    El vidrio AR y su presentación en forma de fibras de refuerzo, fue diseñado para ser inerte a los álcalis de los cementos. Por este motivo se viene utilizando desde hace varias décadas como refuerzo de morteros y hormigones en forma de fibra corta. El ensimaje que estas fibras de vidrio de refuerzo A R presentaba en su origen no era compatible con resinas de tipo sintéticas, por lo que el refuerzo era exclusivo para cementos y hormigones fuera cual fuera la aplicación, formato o proceso productivo. Recientemente, gracias al desarrollo específico de ensimajes especiales acordes a las fibras de vidrio AR ha aparecido la misma tipología de vidrio AR como refuerzo en forma de fibra continua compatible con resinas sint

  8. Max Auwaerter Price lecture: building and probing atomic structures

    International Nuclear Information System (INIS)

    Ternes, M.

    2008-01-01

    Full text: The control of the geometric, electronic, and magnetic properties of atomic-scale nanostructures is a prerequisite for the understanding and fabrication of new materials and devices. Two routes lead towards this goal: Atomic manipulation of single atoms and molecules by scanning probe microscopy, or patterning using self-assembly. Atomic manipulation has been performed since almost 20 years, but it has been difficult to answer the simple question: how much force does it take to manipulate atoms and molecules on surfaces? To address this question, we used a combined atomic force and scanning tunneling microscope to simultaneously measure the force and the current between an adsorbate and a tip during atomic manipulation. We found that the force it takes to move an atom depends crucially on the binding between adsorbate and surface. Our results indicate that for moving metal atoms on metal surfaces, the lateral force component plays the dominant role. Measuring the forces during manipulation yielded the full potential energy landscape of the tip-sample interaction. Surprisingly, the potential energy barriers are comparable to diffusion barriers, which are obtained in the absence of a probe tip. Furthermore, we used the scanning tunneling microscope to assemble magnetic structures on a thin insulator. We found, that the spin of the atom is influenced by the magnetocrystalline anisotropy of the supporting surface which lifts the spin degeneracy of the ground state and enables the identification of individual atoms. The ground state of atoms with half-integer spin remains always degenerated at zero field due to Kramers theorem. We found that if these states differ by an orbital momentum of m = ±1 the localized spin is screened by the surrounding conducting electrons of the non-magnetic host and form a many-electron spin-singlet at sufficiently low temperature. (author)

  9. Building Structural Complexity in Semiconductor Nanocrystals through Chemical Transformations

    Energy Technology Data Exchange (ETDEWEB)

    Sadtler, Bryce F [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2009-05-01

    Ag2S lattices were used to calculate interface formation energies. The formation energies indicate the favorability for interface nucleation at different facets of the nanorod and the stability of the interfaces during growth of the secondary material (Cu2S or Ag2S) within the CdS nanocrystal. The physical properties of the CdS-Ag2S and CdS-Cu2S binary nanorods are discussed in terms of the electronic structure of their components and the heterostructure morphology.

  10. A case study on the structural assessment of fire damaged building

    Science.gov (United States)

    Osman, M. H.; Sarbini, N. N.; Ibrahim, I. S.; Ma, C. K.; Ismail, M.; Mohd, M. F.

    2017-11-01

    This paper presents a case study on the structural assessment of building damaged by fire and discussed on the site investigations and test results prior to determine the existing condition of the building. The building was on fire for about one hour before it was extinguished. In order to ascertain the integrity of the building, a visual inspection was conducted for all elements (truss, beam, column and wall), followed by non-destructive, load and material tests. The load test was conducted to determine the ability of truss to resist service load, while the material test to determine the residual strength of the material. At the end of the investigation, a structural analysis was carried out to determine the new factor of safety by considering the residual strength. The highlighted was on the truss element due to steel behaviour that is hardly been predicted. Meanwhile, reinforced concrete elements (beam, column and wall) were found externally affected and caused its strength to be considered as sufficient for further used of building. The new factor of safety is equal to 2, considered as the minimum calculated value for the truss member. Therefore, this fire damaged building was found safe and can be used for further application.

  11. RESRAD-BUILD: A model to estimate dose from contaminated structures. Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    The RESRAD-BUILD model is an exposure pathway and analysis code used to determine whether radiologically contaminated buildings and structures can be free released for a specific land use (e.g., residential or industrial). The model provides estimates of dose to a hypothetical receptor from the structure. The RESRAD-BUILD technology can calculate dose from variety of site-specific hypothetical scenarios, decay-time intervals, and radionuclides. When using the RESRAD-BUILD code, specific project assumptions must be developed with the appropriate regulatory agencies, especially the cleanup criteria and the exposure scenario to be used. The C Reactor demonstration of RESRAD-BUILD modeled hypothetical future use of below grade portions of the reactor building complex. A residential exposure scenario with a cleanup criteria of 15 mrem/yr above background (Environmental Protection Agency [EPA] draft guidance) was used to coordinate decommissioning with adjacent ongoing remedial actions conducted in accordance with an existing Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) Record of Decision. This paper gives a description of the technology and discusses its performance, applications, cost, regulatory and policy issues, and lessons learned.

  12. RESRAD-Build: A model to estimate dose from contaminated structures. Innovative technology summary report

    International Nuclear Information System (INIS)

    1998-12-01

    The RESRAD-BUILD model is an exposure pathway and analysis code used to determine whether radiologically contaminated buildings and structures can be free released for a specific land use (e.g., residential or industrial). The model provides estimates of dose to a hypothetical receptor from the structure. The RESRAD-BUILD technology can calculate dose from variety of site-specific hypothetical scenarios, decay-time intervals, and radionuclides. When using the RESRAD-BUILD code, specific project assumptions must be developed with the appropriate regulatory agencies, especially the cleanup criteria and the exposure scenario to be used. The C Reactor demonstration of RESRAD-BUILD modeled hypothetical future use of below grade portions of the reactor building complex. A residential exposure scenario with a cleanup criteria of 15 mrem/yr above background (Environmental Protection Agency [EPA] draft guidance) was used to coordinate decommissioning with adjacent ongoing remedial actions conducted in accordance with an existing Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) Record of Decision. This paper gives a description of the technology and discusses its performance, applications, cost, regulatory and policy issues, and lessons learned

  13. Effect of nonlinearity of connecting dampers on vibration control of connected building structures

    Directory of Open Access Journals (Sweden)

    Masatoshi eKasagi

    2016-01-01

    Full Text Available The connection of two building structures with dampers is one of effective vibration control systems. In this vibration control system, both buildings have to possess different vibration properties in order to provide a higher vibration reduction performance. In addition to such condition of different vibration properties of both buildings, the connecting dampers also play an important role in the vibration control mechanism. In this paper, the effect of nonlinearity of connecting dampers on the vibration control of connected building structures is investigated in detail. A high-damping rubber damper and an oil damper with and without relief mechanism are treated. It is shown that, while the high-damping rubber damper is effective in a rather small deformation level, the linear oil damper is effective in a relatively large deformation level. It is further shown that, while the oil dampers reduce the response in the same phase as the case without dampers, the high-damping rubber dampers change the phase. The merit is that the high-damping rubber can reduce the damper deformation and keep the sufficient space between both buildings. This can mitigate the risk of building pounding.

  14. Process and a device for manufacturing a composite building panel for use in a building structure cladding system

    Energy Technology Data Exchange (ETDEWEB)

    Tetu, B

    1991-06-11

    A process and device are disclosed for manufacturing a composite panel used for cladding a building. The panel comprises a facing layer made from a plurality of facing elements, such as brick slices, retained in a spaced-apart relationship, and magnetically attractible particulate material disposed between the facing elements to imitate mortar. A rigid backing layer is provided, spaced from the spacing layer, and the space between the facing and the backing layers is filled with an insulation/bonding layer, made of urethane foam. The device for manufacturing the panel comprises a facing element holder in the form of a structure with a plurality of recesses for receiving facing elements, also including spacers between the recesses in order to retain the facing elements in a spaced-apart relationship. Ceramic magnets are provided on the spacers for temporarily retaining the particulate material against gravity until the insulation/bonding layer is built which retains all the panel elements together. The invention enables manufacture of non-planar panels, such as those used on corners of buildings, thereby eliminating the need for a corner joint. 9 figs.

  15. Implementation of the ANNs ensembles in macro-BIM cost estimates of buildings' floor structural frames

    Science.gov (United States)

    Juszczyk, Michał

    2018-04-01

    This paper reports some results of the studies on the use of artificial intelligence tools for the purposes of cost estimation based on building information models. A problem of the cost estimates based on the building information models on a macro level supported by the ensembles of artificial neural networks is concisely discussed. In the course of the research a regression model has been built for the purposes of cost estimation of buildings' floor structural frames, as higher level elements. Building information models are supposed to serve as a repository of data used for the purposes of cost estimation. The core of the model is the ensemble of neural networks. The developed model allows the prediction of cost estimates with satisfactory accuracy.

  16. Economic Feasibility Analysis of the Application of Geothermal Energy Facilities to Public Building Structures

    Directory of Open Access Journals (Sweden)

    Sangyong Kim

    2014-03-01

    Full Text Available This study aims to present an efficient plan for the application of a geothermal energy facility at the building structure planning phase. Energy consumption, energy cost and the primary energy consumption of buildings were calculated to enable a comparison of buildings prior to the application of a geothermal energy facility. The capacity for energy savings and the costs related to the installation of such a facility were estimated. To obtain more reliable criteria for economic feasibility, the lifecycle cost (LCC analysis incorporated maintenance costs (reflecting repair and replacement cycles based on construction work specifications of a new renewable energy facility and initial construction costs (calculated based on design drawings for its practical installation. It is expected that the findings of this study will help in the selection of an economically viable geothermal energy facility at the building construction planning phase.

  17. Experimental and analytical studies on soil-structure interaction behavior of nuclear reactor building

    International Nuclear Information System (INIS)

    Tsushima, Y.

    1978-01-01

    The purpose of this study is to estimate damping effects due to soil-structure interaction by the dissipation of vibrational energy to the ground through the foundation in a building with a short fundamental period such as a nuclear reactor building. The author performed experimental and analytical studies on the vibrational characteristics of model steel structures ranging from one to four stories high erected on the rigid base and located on soil, which are simulated from the vibrational characteristics of a prototype reactor building: the former study is to obtain damping effects due to inner friction of steel frames and the latter to obtain radiation damping effects due to soil-structure interaction. The author also touches upon the results of experiments performed on a BWR-type reactor building in 1974, which showed damping ratios higher than 20% of those in fundamental modes. Then the author attempts to estimate the damping effects of the reactor building by his own method proposed in the report. Through these studies the author finally concludes that the experimental damping effects are remarkable in the lower modes by the energy dissipation and the analytical results show a fairly good fit to the experimental ones

  18. USAGE OF CONSTRUCTION-ORIENTED SOFTWARE SCAD FOR ANALYSIS OF WORK OF MACHINE-BUILDING STRUCTURES

    Directory of Open Access Journals (Sweden)

    D. О. Bannikov

    2018-02-01

    Full Text Available Purpose. In the case of analysis of work of the machine-building structures, the direct usage of construction-oriented software developments is impossible, since ideology and methodology for solving various tasks in construction and machine-building are different. Therefore, in the conducting of practical calculations, there is a need for a certain adjustment of the approaches put in the program complexes and their adaptation to the engineering industry. The presentation of the author's experience of the construction-oriented software SCAD usage for Windows for analyzing the work of various machine-building structures, their components and assemblies is the immediate purpose of the publication. Methodology. During a long period of time the author was engaged in analyzing the work of building, mainly thin-walled, steel structures using the Finite Element Method based on the SCAD for Windows software package. At the same time, a considerable number of machine-building structures were considered, including railroad rolling stock units. Most of these tasks grew into a scientific and research problem that needed to be thoroughly researched and analyzed before giving design recommendations. Findings. The publication presents more than a dozen different tasks, typical for the machine-building industry, which the author had to deal with. Static and quasi-static problems, the problem of motion in time, the contact problem, the problem of the cracks deve-lopment, the physical and geometric non-linearity are among them. Accordingly, for each of these problems the main challenges, features and practical techniques developed during the work are presented, as well as the constructed finite element models are presented as an illustration. Originality. The experience of construction-oriented software product usage on the basis of the Finite Element Method for analyzing of the work of machine-building structures is generalized. A number of practical methods and

  19. Structural analysis of reactor buildings with help of complete FE models

    International Nuclear Information System (INIS)

    Diaz, B.E.; Vaz, L.E.; Martha, L.F.R.; Costa, E.

    1984-01-01

    The reinforced concrete structures located within the steel containment shell of a Reactor Building are formed by highly complex structures subjected to a large amount of actions due to different causes. The analysis of this complex structure can be performed with help of small models, each one representing a part of the global structure. The interaction effects among the partial models are accounted for in approximate way. This approach has been used previously with entire success in the design of 1300 MW PWR nuclear power plants. However a new and entire different approach can be used in the design of these structures. The entire assembly of structural elements of the building is represented and analyzed with help of a single and very large FE model. This paper will present the main characteristics of this type of analysis as well as all the necessary procedures, which must be implemented for the proper data processing of the forces and the automatic reinforced concrete design of the structural elements of the Reactor Building. (Author) [pt

  20. Chirality-Assisted Electronic Cloaking of Confined States in Bilayer Graphene

    Science.gov (United States)

    Gu, Nan; Rudner, Mark; Levitov, Leonid

    2011-10-01

    We show that the strong coupling of pseudospin orientation and charge carrier motion in bilayer graphene has a drastic effect on transport properties of ballistic p-n-p junctions. Electronic states with zero momentum parallel to the barrier are confined under it for one pseudospin orientation, whereas states with the opposite pseudospin tunnel through the junction totally uninfluenced by the presence of confined states. We demonstrate that the junction acts as a cloak for confined states, making them nearly invisible to electrons in the outer regions over a range of incidence angles. This behavior is manifested in the two-terminal conductance as transmission resonances with non-Lorentzian, singular peak shapes. The response of these phenomena to a weak magnetic field or electric-field-induced interlayer gap can serve as an experimental fingerprint of electronic cloaking.

  1. Transformation of the corner: A shield cloak and a planar retro-reflector

    Science.gov (United States)

    Yang, R.; Lei, Z. Y.; Fan, J.; Gao, D. X.; Wang, Z. X.; Xie, Y. J.

    2013-10-01

    A metallic sheet, coated with a few blocks of all-dielectric isotropic materials, is presented for creating an illusion or an image of a corner based on quasi-conformal transformation optics. On the one hand, our design is able to generate cloaking effects to conceal objects hiding inside a corner. On the other hand, we propose to use such a planar transformation device to represent a corner reflector that reflects light directly back to its source. The full wave simulation shows our device is capable of operating considerably well in a broad frequency range, and presents only the appearance of a bare corner functioning as a shield cloak or a planar retro-reflector.

  2. BIM-Based Timber Structures Refurbishment of the Immovable Heritage Listed Buildings

    Science.gov (United States)

    Henek, Vladan; Venkrbec, Václav

    2017-12-01

    The use of Building information model (BIM) design tools is no longer an exception, but a common issue. When designing new buildings or complex renovations using BIM, the benefits have already been repeatedly published. The essence of BIM is to create a multidimensional geometric model of a planned building electronically on a computer, supplemented with the necessary information in advance of the construction process. Refurbishment is a specific process that combines both - new structures and demolished structures, or structures that need to be dismantled, repaired, and then returned to the original position. Often it can be historically valuable part of the building. BIM-based repairs and refurbishments of the constructions, especially complicated repairs of the structures of roof trusses of immovable heritage listed buildings, have not yet been credibly presented. However, the use of BIM tools may be advantageous in this area, because user can quickly response to the necessary changes that may be needed during refurbishments, but also in connection with the quick assessment and cost estimation of any unexpected additional works. The paper deals with the use of BIM in the field of repairs and refurbishment of the buildings in general. The emphasis on monumentally protected elements was priority. Advantage of the proposal research is demonstrated on case study of the refurbishment of the immovable heritage listed truss roof. According to this study, this construction was realized in the Czech Republic. Case study consists of 3D modelled truss parts and the connected technological workflow base. The project work was carried out in one common model environment.

  3. Feasibility study tool for semi-rigid joints design of high-rise buildings steel structures

    Science.gov (United States)

    Bagautdinov, Ruslan; Monastireva, Daria; Bodak, Irina; Potapova, Irina

    2018-03-01

    There are many ways to consider the final cost of the high-rise building structures and to define, which of their different variations are the most effective from different points of view. The research of Jaakko Haapio is conducted in Tampere University of Technology, which aims to develop a method that allows determining the manufacturing and installation costs of steel structures already at the tender phase while taking into account their details. This paper is aimed to make the analysis of the Feature-Based Costing Method for skeletal steel structures proposed by Jaakko Haapio. The most appropriate ways to improve the tool and to implement it in the Russian circumstances for high-rise building design are derived. Presented tool can be useful not only for the designers but, also, for the steel structures manufacturing organizations, which can help to utilize BIM technologies in the organization process and controlling on the factory.

  4. Feasibility study tool for semi-rigid joints design of high-rise buildings steel structures

    Directory of Open Access Journals (Sweden)

    Bagautdinov Ruslan

    2018-01-01

    Full Text Available There are many ways to consider the final cost of the high-rise building structures and to define, which of their different variations are the most effective from different points of view. The research of Jaakko Haapio is conducted in Tampere University of Technology, which aims to develop a method that allows determining the manufacturing and installation costs of steel structures already at the tender phase while taking into account their details. This paper is aimed to make the analysis of the Feature-Based Costing Method for skeletal steel structures proposed by Jaakko Haapio. The most appropriate ways to improve the tool and to implement it in the Russian circumstances for high-rise building design are derived. Presented tool can be useful not only for the designers but, also, for the steel structures manufacturing organizations, which can help to utilize BIM technologies in the organization process and controlling on the factory.

  5. Influence of Structural Periodicity on Vibration Transmission in a Multi-Storey Wooden Building

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard

    2013-01-01

    Noise is a nuisance to people, and buildings should therefore be designed to prevent propagation of sound and vibration in the audible frequency range as well as the range of frequencies relevant to whole-body vibrations of humans. In heavy structures made of concrete and masonry, a source...

  6. 49 CFR 1242.26 - Miscellaneous building and structures (account XX-19-28).

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Miscellaneous building and structures (account XX... XX-19-28). Separate common expenses as specific facts indicate or according to distribution of common expenses listed in § 1242.10, Administration-Track (account XX-19-02). ...

  7. Extent of moisture and mould damage in structures of public buildings

    Directory of Open Access Journals (Sweden)

    Petri J. Annila

    2017-06-01

    Full Text Available The study concentrated on the extent of moisture and mould damage in different structures in 25 public buildings in Finland. Users of all the buildings had health symptoms suspected to be the result of moisture and mould damage, which is why moisture performance assessments had been performed. The assessment reports on each building were available as research material. The reports indicated that the examined buildings suffered from multiple moisture and mould problems in several different structures. On average, however, a relatively small proportion of the total number of structures had suffered damage. On the basis of the research material, damage was most extensive in walls in soil contact (16.3% and base floor structures (12.5%. The lowest damage rates were found in partition walls (2.4%, external walls (2.6% and intermediate floors (2.5%. The results of the study underline the importance of thorough moisture performance assessments to ensure that all point-sized moisture and mould damage is detected.

  8. PRE-CAST WALL PRODUCTS MADE FROM LIGHTWEIGHT CONCRETE FOR ENCLOSING STRUCTURES OF BUILDINGS

    Directory of Open Access Journals (Sweden)

    M. R. Hadgiev

    2014-01-01

    Full Text Available The paper is devoted to the actual problem waste dismantling of buildings and structures in the form of brick waste with reception the secondary fine and coarse aggregate and concrete based on them for the manufacture of small-piece wall products. 

  9. Presence of microplastics in the tube structure of the reef-building ...

    African Journals Online (AJOL)

    The prevalence of microplastics in the marine environment has resulted in a need to understand their association with various fauna. The aim of this study was to assess whether microplastic particles are present in the tube structure of the indigenous reef-building polychaete Gunnarea gaimardi, which occurs along the ...

  10. Automated determination of fibrillar structures by simultaneous model building and fiber diffraction refinement.

    Science.gov (United States)

    Potrzebowski, Wojciech; André, Ingemar

    2015-07-01

    For highly oriented fibrillar molecules, three-dimensional structures can often be determined from X-ray fiber diffraction data. However, because of limited information content, structure determination and validation can be challenging. We demonstrate that automated structure determination of protein fibers can be achieved by guiding the building of macromolecular models with fiber diffraction data. We illustrate the power of our approach by determining the structures of six bacteriophage viruses de novo using fiber diffraction data alone and together with solid-state NMR data. Furthermore, we demonstrate the feasibility of molecular replacement from monomeric and fibrillar templates by solving the structure of a plant virus using homology modeling and protein-protein docking. The generated models explain the experimental data to the same degree as deposited reference structures but with improved structural quality. We also developed a cross-validation method for model selection. The results highlight the power of fiber diffraction data as structural constraints.

  11. Total reflection and cloaking by zero index metamaterials loaded with rectangular dielectric defects

    KAUST Repository

    Wu, Ying

    2013-05-06

    In this work, we investigate wave transmission property through a zero index metamaterial (ZIM) waveguide embedded with rectangular dielectric defects. We show that total reflection and total transmission (cloaking) can be achieved by adjusting the geometric sizes and/or permittivities of the defects. Our work provides another possibility of manipulating wave propagation through ZIM in addition to the widely studied dielectric defects with cylindrical geometries.

  12. Total reflection and cloaking by zero index metamaterials loaded with rectangular dielectric defects

    KAUST Repository

    Wu, Ying; Li, Jichun

    2013-01-01

    In this work, we investigate wave transmission property through a zero index metamaterial (ZIM) waveguide embedded with rectangular dielectric defects. We show that total reflection and total transmission (cloaking) can be achieved by adjusting the geometric sizes and/or permittivities of the defects. Our work provides another possibility of manipulating wave propagation through ZIM in addition to the widely studied dielectric defects with cylindrical geometries.

  13. TLCD Parametric Optimization for the Vibration Control of Building Structures Based on Linear Matrix Inequality

    OpenAIRE

    Huo, Linsheng; Qu, Chunxu; Li, Hongnan

    2014-01-01

    Passive liquid dampers have been used to effectively reduce the dynamic response of civil infrastructures subjected to earthquakes or strong winds. The design of liquid dampers for structural vibration control involves the determination of the optimal parameters. This paper presents an optimal design methodology for tuned liquid column dampers (TLCDs) based on the H∞ control theory. A practical structure, Dalian Xinghai Financial Business Building, is used to illustrate the feasibility of the...

  14. Trends in the structures development of the regional machine-building complex

    Directory of Open Access Journals (Sweden)

    Ershova I.V.

    2017-01-01

    Full Text Available In the process of market reforms of the Russian machine-building complex several distinct periods can be revealed. In this article the authors define periods of mass disintegration and spontaneous integration (since the beginning of the reforms until the financial crisis of 1996, post-crisis stabilization, directional specialization (2000-2008 and evolutionary development (since 2010. The economic consequences of the enterprises mergers and divisions are shown on the example of machine-building enterprises of the Middle Urals. The aim of this study is to substantiate the methodical approach to the selection of the optimal organizational structure for the machine-building business. The necessity of taking into account the extent of the personnel diversification and the production volume has been revealed for the optimum organizational structure determination in the machine-building associations. The authors have analyzed sales profitability of the 2745 machine-building enterprises, depending on the production scale and industry sector. The factors affecting the development of cooperative ties and outsourcing have been defined. The authors have made a conclusion that it is necessary to form technological chains as a new kind of business associations.

  15. A Framework for Occupancy Tracking in a Building via Structural Dynamics Sensing of Footstep Vibrations

    Directory of Open Access Journals (Sweden)

    Jeffrey D. Poston

    2017-11-01

    Full Text Available Counting the number of occupants in building areas over time—occupancy tracking—provides valuable information for responding to emergencies, optimizing thermal conditions or managing personnel. This capability is distinct from tracking individual building occupants as they move within a building, has lower complexity than conventional tracking algorithms require, and avoids privacy concerns that tracking individuals may pose. The approach proposed here is a novel combination of data analytics applied to measurements from a building’s structural dynamics sensors (e.g., accelerometers or geophones. Specifically, measurements of footstep-generated structural waves provide evidence of occupancy in a building area. These footstep vibrations can be distinguished from other vibrations, and, once identified, the footsteps can be located. These locations, in turn, form the starting point of estimating occupancy in an area. In order to provide a meaningful occupancy count, however, it is first necessary to associate discrete footsteps with individuals. The proposed framework incorporates a tractable algorithm for this association task. The proposed algorithms operate online, updating occupancy count over time as new footsteps are detected. Experiments with measurements from a public building illustrate the operation of the proposed framework. This approach offers an advantage over others based on conventional technologies by avoiding the cost of a separate sensor system devoted to occupancy tracking.

  16. Increasing the density of passive photonic-integrated circuits via nanophotonic cloaking

    Science.gov (United States)

    Shen, Bing; Polson, Randy; Menon, Rajesh

    2016-11-01

    Photonic-integrated devices need to be adequately spaced apart to prevent signal cross-talk. This fundamentally limits their packing density. Here we report the use of nanophotonic cloaking to render neighbouring devices invisible to one another, which allows them to be placed closer together than is otherwise feasible. Specifically, we experimentally demonstrated waveguides that are spaced by a distance of ~λ0/2 and designed waveguides with centre-to-centre spacing as small as 600 nm (-2 dB and an extinction ratio >15 dB over a bandwidth larger than 60 nm. This performance can be improved with better design algorithms and industry-standard lithography. The nanophotonic cloak relies on multiple guided-mode resonances, which render such devices very robust to fabrication errors. Our devices are broadly complimentary-metal-oxide-semiconductor compatible, have a minimum pitch of 200 nm and can be fabricated with a single lithography step. The nanophotonic cloaks can be generally applied to all passive integrated photonics.

  17. Increasing the density of passive photonic-integrated circuits via nanophotonic cloaking.

    Science.gov (United States)

    Shen, Bing; Polson, Randy; Menon, Rajesh

    2016-11-09

    Photonic-integrated devices need to be adequately spaced apart to prevent signal cross-talk. This fundamentally limits their packing density. Here we report the use of nanophotonic cloaking to render neighbouring devices invisible to one another, which allows them to be placed closer together than is otherwise feasible. Specifically, we experimentally demonstrated waveguides that are spaced by a distance of ∼λ 0 /2 and designed waveguides with centre-to-centre spacing as small as 600 nm (-2 dB and an extinction ratio >15 dB over a bandwidth larger than 60 nm. This performance can be improved with better design algorithms and industry-standard lithography. The nanophotonic cloak relies on multiple guided-mode resonances, which render such devices very robust to fabrication errors. Our devices are broadly complimentary-metal-oxide-semiconductor compatible, have a minimum pitch of 200 nm and can be fabricated with a single lithography step. The nanophotonic cloaks can be generally applied to all passive integrated photonics.

  18. The thermal impact of subsurface building structures on urban groundwater resources - A paradigmatic example.

    Science.gov (United States)

    Epting, Jannis; Scheidler, Stefan; Affolter, Annette; Borer, Paul; Mueller, Matthias H; Egli, Lukas; García-Gil, Alejandro; Huggenberger, Peter

    2017-10-15

    Shallow subsurface thermal regimes in urban areas are increasingly impacted by anthropogenic activities, which include infrastructure development like underground traffic lines as well as industrial and residential subsurface buildings. In combination with the progressive use of shallow geothermal energy systems, this results in the so-called subsurface urban heat island effect. This article emphasizes the importance of considering the thermal impact of subsurface structures, which commonly is underestimated due to missing information and of reliable subsurface temperature data. Based on synthetic heat-transport models different settings of the urban environment were investigated, including: (1) hydraulic gradients and conductivities, which result in different groundwater flow velocities; (2) aquifer properties like groundwater thickness to aquitard and depth to water table; and (3) constructional features, such as building depths and thermal properties of building structures. Our results demonstrate that with rising groundwater flow velocities, the heat-load from building structures increase, whereas down-gradient groundwater temperatures decrease. Thermal impacts on subsurface resources therefore have to be related to the permeability of aquifers and hydraulic boundary conditions. In regard to the urban settings of Basel, Switzerland, flow velocities of around 1 md -1 delineate a marker where either down-gradient temperature deviations or heat-loads into the subsurface are more relevant. Furthermore, no direct thermal influence on groundwater resources should be expected for aquifers with groundwater thicknesses larger 10m and when the distance of the building structure to the groundwater table is higher than around 10m. We demonstrate that measuring temperature changes down-gradient of subsurface structures is insufficient overall to assess thermal impacts, particularly in urban areas. Moreover, in areas which are densely urbanized, and where groundwater flow

  19. Structural health monitoring on medium rise reinforced concrete building using ambient vibration method

    Science.gov (United States)

    Kamarudin, A. F.; Mokhatar, S. N.; Zainal Abidin, M. H.; Daud, M. E.; Rosli, M. S.; Ibrahim, A.; Ibrahim, Z.; Noh, M. S. Md

    2018-04-01

    Monitoring of structural health from initial stage of building construction to its serviceability is an ideal practise to assess for any structural defects or damages. Structural integrity could be intruded by natural destruction or structural deterioration, and worse if without remedy action on monitoring, building re-assessment or maintenance is taken. In this study the application of ambient vibration (AV) testing is utilized to evaluate the health of eighth stories medium rise reinforced concrete building in Universiti Tun Hussein Onn Malaysia (UTHM), based comparison made between the predominant frequency, fo, determined in year 2012 and 2017. For determination of fo, popular method of Fourier Amplitude Spectra (FAS) was used to transform the ambient vibration time series by using 1 Hz tri-axial seismometer sensors and City SharkII data recorder. From the results, it shows the first mode frequencies from FAS curves indicate at 2.04 Hz in 2012 and 1.97 Hz in 2017 with only 3.14% of frequency reduction. However, steady state frequencies shown at the second and third modes frequencies of 2.42 Hz and 3.31 Hz by both years. Two translation mode shapes were found at the first and second mode frequencies in the North-South (NS-parallel to building transverse axis) and East-West (EsW-parallel to building longitudinal axis) components, and the torsional mode shape shows as the third mode frequency in both years. No excessive deformation amplitude was found at any selective floors based on comparison made between three mode shapes produced, that could bring to potential feature of structural deterioration. Low percentages of natural frequency disparity within five years of duration interval shown by the first mode frequencies under ambient vibration technique was considered in good health state, according to previous researchers recommendation at acceptable percentages below 5 to 10% over the years.

  20. Modelling of internal structure in seismic analysis of a PHWR building

    International Nuclear Information System (INIS)

    Reddy, G.R.; Vaze, K.K.; Kushawaha, H.S.; Ingle, R.K.; Subramanian, K.V.

    1991-01-01

    Seismic analysis of complex and large structures, consisting of thick shear walls, such as Reactor Building is very involved and time consuming. It is a standard practice to model the structure as a stick model to predict reasonably the dynamic behaviour of the structure. It is required to determine approximate equivalent sectional properties of Internal Structure for representation in the stick model. The restraint to warping can change the stress distribution thus affecting the centre of rigidity and torsional inertia, Hence, standard formulae does not hold good for determination of sectional properties of the Internal Structure. In this case the equivalent sectional properties for the Internal Structure are calculated using a Finite Element Model (FEM) of the Internal Structure and applying unit horizontal forces in each direction. A 3-D stick model is developed using the guidelines. Using the properties calculated by FEM and also by standard formulae, the responses of the 3-D stick model are compared. (J.P.N.)

  1. Principles of structural physics in building construction in the Egyptian desert

    Energy Technology Data Exchange (ETDEWEB)

    Awady El Wakil, Shafak El

    1981-12-01

    Building construction in accordance with the climate in oases of the Egyptian desert is discussed. Climatic conditions and the resulting consequences for structural physics play a major role. With the aid of Olgay's comfort diagram, requirements to be made on buildings in various oases are derived from the climatic data of these oases. To optimize the indoor climate, shading, heat storage and ventilation measures are discussed, and suggestions are made on how to make use of this knowledge in consideration of traditional Egyptian architecture.

  2. Evaluation of Structural Robustness against Column Loss: Methodology and Application to RC Frame Buildings.

    Science.gov (United States)

    Bao, Yihai; Main, Joseph A; Noh, Sam-Young

    2017-08-01

    A computational methodology is presented for evaluating structural robustness against column loss. The methodology is illustrated through application to reinforced concrete (RC) frame buildings, using a reduced-order modeling approach for three-dimensional RC framing systems that includes the floor slabs. Comparisons with high-fidelity finite-element model results are presented to verify the approach. Pushdown analyses of prototype buildings under column loss scenarios are performed using the reduced-order modeling approach, and an energy-based procedure is employed to account for the dynamic effects associated with sudden column loss. Results obtained using the energy-based approach are found to be in good agreement with results from direct dynamic analysis of sudden column loss. A metric for structural robustness is proposed, calculated by normalizing the ultimate capacities of the structural system under sudden column loss by the applicable service-level gravity loading and by evaluating the minimum value of this normalized ultimate capacity over all column removal scenarios. The procedure is applied to two prototype 10-story RC buildings, one employing intermediate moment frames (IMFs) and the other employing special moment frames (SMFs). The SMF building, with its more stringent seismic design and detailing, is found to have greater robustness.

  3. Automatic Generation of Structural Building Descriptions from 3D Point Cloud Scans

    DEFF Research Database (Denmark)

    Ochmann, Sebastian; Vock, Richard; Wessel, Raoul

    2013-01-01

    We present a new method for automatic semantic structuring of 3D point clouds representing buildings. In contrast to existing approaches which either target the outside appearance like the facade structure or rather low-level geometric structures, we focus on the building’s interior using indoor...... scans to derive high-level architectural entities like rooms and doors. Starting with a registered 3D point cloud, we probabilistically model the affiliation of each measured point to a certain room in the building. We solve the resulting clustering problem using an iterative algorithm that relies...... on the estimated visibilities between any two locations within the point cloud. With the segmentation into rooms at hand, we subsequently determine the locations and extents of doors between adjacent rooms. In our experiments, we demonstrate the feasibility of our method by applying it to synthetic as well...

  4. Life Comparative Analysis of Energy Consumption and CO2 Emissions of Different Building Structural Frame Types

    Science.gov (United States)

    Kim, Sangyong; Moon, Joon-Ho; Shin, Yoonseok; Kim, Gwang-Hee; Seo, Deok-Seok

    2013-01-01

    The objective of this research is to quantitatively measure and compare the environmental load and construction cost of different structural frame types. Construction cost also accounts for the costs of CO2 emissions of input materials. The choice of structural frame type is a major consideration in construction, as this element represents about 33% of total building construction costs. In this research, four constructed buildings were analyzed, with these having either reinforced concrete (RC) or steel (S) structures. An input-output framework analysis was used to measure energy consumption and CO2 emissions of input materials for each structural frame type. In addition, the CO2 emissions cost was measured using the trading price of CO2 emissions on the International Commodity Exchange. This research revealed that both energy consumption and CO2 emissions were, on average, 26% lower with the RC structure than with the S structure, and the construction costs (including the CO2 emissions cost) of the RC structure were about 9.8% lower, compared to the S structure. This research provides insights through which the construction industry will be able to respond to the carbon market, which is expected to continue to grow in the future. PMID:24227998

  5. Life Comparative Analysis of Energy Consumption and CO2 Emissions of Different Building Structural Frame Types

    Directory of Open Access Journals (Sweden)

    Sangyong Kim

    2013-01-01

    Full Text Available The objective of this research is to quantitatively measure and compare the environmental load and construction cost of different structural frame types. Construction cost also accounts for the costs of CO2 emissions of input materials. The choice of structural frame type is a major consideration in construction, as this element represents about 33% of total building construction costs. In this research, four constructed buildings were analyzed, with these having either reinforced concrete (RC or steel (S structures. An input-output framework analysis was used to measure energy consumption and CO2 emissions of input materials for each structural frame type. In addition, the CO2 emissions cost was measured using the trading price of CO2 emissions on the International Commodity Exchange. This research revealed that both energy consumption and CO2 emissions were, on average, 26% lower with the RC structure than with the S structure, and the construction costs (including the CO2 emissions cost of the RC structure were about 9.8% lower, compared to the S structure. This research provides insights through which the construction industry will be able to respond to the carbon market, which is expected to continue to grow in the future.

  6. Coupling of impedance functions to nuclear reactor building for soil-structure interaction analysis

    International Nuclear Information System (INIS)

    Danisch, R.; Delinic, K.; Trbojevic, V.M.

    1991-01-01

    Finite element model of a nuclear reactor building is coupled to complex soil impedance functions and soil-structure-interaction analysis is carried out in frequency domain. In the second type of analysis applied in this paper, soil impedance functions are used to evaluate equivalent soil springs and dashpots of soil. These are coupled to the structure model in order to carry out the time marching analysis. Three types of soil profiles are considered: hard, medium and soft. Results of two analyzes are compared on the same structural model. Equivalent soil springs and dashpots are determined using new method based on the least square approximation. (author)

  7. Using Openstreetmap Data to Generate Building Models with Their Inner Structures for 3d Maps

    Science.gov (United States)

    Wang, Z.; Zipf, A.

    2017-09-01

    With the development of Web 2.0, more and more data related to indoor environments has been collected within the volunteered geographic information (VGI) framework, which creates a need for construction of indoor environments from VGI. In this study, we focus on generating 3D building models from OpenStreetMap (OSM) data, and provide an approach to support construction and visualization of indoor environments on 3D maps. In this paper, we present an algorithm which can extract building information from OSM data, and can construct building structures as well as inner building components (e.g., doors, rooms, and windows). A web application is built to support the processing and visualization of the building models on a 3D map. We test our approach with an indoor dataset collected from the field. The results show the feasibility of our approach and its potentials to provide support for a wide range of applications, such as indoor and outdoor navigation, urban planning, and incident management.

  8. USING OPENSTREETMAP DATA TO GENERATE BUILDING MODELS WITH THEIR INNER STRUCTURES FOR 3D MAPS

    Directory of Open Access Journals (Sweden)

    Z. Wang

    2017-09-01

    Full Text Available With the development of Web 2.0, more and more data related to indoor environments has been collected within the volunteered geographic information (VGI framework, which creates a need for construction of indoor environments from VGI. In this study, we focus on generating 3D building models from OpenStreetMap (OSM data, and provide an approach to support construction and visualization of indoor environments on 3D maps. In this paper, we present an algorithm which can extract building information from OSM data, and can construct building structures as well as inner building components (e.g., doors, rooms, and windows. A web application is built to support the processing and visualization of the building models on a 3D map. We test our approach with an indoor dataset collected from the field. The results show the feasibility of our approach and its potentials to provide support for a wide range of applications, such as indoor and outdoor navigation, urban planning, and incident management.

  9. Structural observability analysis and EKF based parameter estimation of building heating models

    Directory of Open Access Journals (Sweden)

    D.W.U. Perera

    2016-07-01

    Full Text Available Research for enhanced energy-efficient buildings has been given much recognition in the recent years owing to their high energy consumptions. Increasing energy needs can be precisely controlled by practicing advanced controllers for building Heating, Ventilation, and Air-Conditioning (HVAC systems. Advanced controllers require a mathematical building heating model to operate, and these models need to be accurate and computationally efficient. One main concern associated with such models is the accurate estimation of the unknown model parameters. This paper presents the feasibility of implementing a simplified building heating model and the computation of physical parameters using an off-line approach. Structural observability analysis is conducted using graph-theoretic techniques to analyze the observability of the developed system model. Then Extended Kalman Filter (EKF algorithm is utilized for parameter estimates using the real measurements of a single-zone building. The simulation-based results confirm that even with a simple model, the EKF follows the state variables accurately. The predicted parameters vary depending on the inputs and disturbances.

  10. Document turn-over analysis to determine need of NPP construction in build-up structures of reinforced concrete

    International Nuclear Information System (INIS)

    Vojpe, D.K.; Lyubavin, V.K.

    1986-01-01

    Document turn-over to determine used of NPP construction in build-up structures of reinforced concrete is carried out. Ways of improving determination of needs of NPP construction board in the mentioned structures are pointed out

  11. Condition Assessment of the Timber Structures of a Century-Old Industrial Building Using a Nondestructive Inspection Procedure

    Science.gov (United States)

    Xiping Wang; Marko Teder; James Wacker

    2013-01-01

    This paper reports an in situ inspection project conducted on heavy timber structures of a century-old industrial building at a paper manufacturing facility. A nondestructive inspection procedure was employed to evaluate the true condition of the heavy timbers that serve as the main framing structure of the building. The on-site investigation involved monitoring of the...

  12. Active pipe-embedded structures in buildings for utilizing low-grade energy sources: A review

    International Nuclear Information System (INIS)

    Xu, Xinhua; Wang, Jinbo; Wang, Shengwei; Xiao, Fu

    2010-01-01

    Low-grade energy sources such as geothermal energy, favorable ambient air and industrial waste heat etc. exist widely. Sufficient utilization of these low-grade energy sources may reduce our daily dependence on high-grade energy sources such as electricity resulting in reduced emission of green house gas for environmental conservation. Active pipe-embedded structure as floor/ceiling usually with water as the medium to carry heat or coolth may utilize these low-grade energy sources for providing space air-conditioning. Compact arrangement of pipes in the structure may significantly enlarge heat transfer surface between the slab mass and water in the pipe allowing substantial heat flows even for relatively small temperature differences. Application of the heat or coolth storage capacity of this structure for preheating or pre-cooling is also one among the advantages of this structure for shifting load and exploiting the nighttime cheap electricity tariff in some regions. This paper presents the technology of the active pipe-embedded structure for utilizing widely existing low-grade energy sources following by a comprehensive review on the heat transfer calculation models of this structure and its practical applications in real building systems for space air-conditioning. This review shows that more works on the active structure, especially simple and transient models for dynamic and accurate performance prediction and easy integration with existing building energy simulation packages, are worthwhile for further promoting the practical application wherever the low-grade energy sources are favorable. (author)

  13. Analysis, Design, and Construction of a Base-Isolated Multiple Building Structure

    Directory of Open Access Journals (Sweden)

    Stefano Sorace

    2014-01-01

    Full Text Available The analysis and design of a multiple residential building, seismically protected by a base isolation system incorporating double friction pendulum sliders as protective devices, are presented in the paper. The building, situated in the suburban area of Florence, is composed of four independent reinforced concrete framed structures, mutually separated by three thermal expansion joints. The plan is L-shaped, with dimensions of about 75 m in the longitudinal direction and about 30 m along the longest side of the transversal direction. These characteristics identify the structure as the largest example of a base-isolated “artificial ground” ever built in Italy. The base isolation solution guarantees lower costs, a much greater performance, and a finer architectural look, as compared to a conventional fixed-base antiseismic design. The characteristics of the building and the isolators, the mechanical properties and the experimental characterization campaign and preliminary sizing carried out on the latter, and the nonlinear time-history design and performance assessment analyses developed on the base isolated building are reported in this paper, along with details about the installation of the isolators and the plants and highlights of the construction works.

  14. Routing Corners of Building Structures - by the Method of Vector Addition - Measured with RTN GNSS Surveying Technology

    Science.gov (United States)

    Krzyżek, Robert

    2015-12-01

    The paper deals with the problem of surveying buildings in the RTN GNSS mode using modernized indirect methods of measurement. As a result of the classical realtime measurements using indirect methods (intersection of straight lines or a point on a straight line), we obtain a building structure (a building) which is largely deformed. This distortion is due to the inconsistency of the actual dimensions of the building (tie distances) relative to the obtained measurement results. In order to eliminate these discrepancies, and thus to ensure full consistency of the building geometric structure, an innovative solution was applied - the method of vector addition - to modify the linear values (tie distances) of the external face of the building walls. A separate research problem tackled in the article, although not yet fully solved, is the issue of coordinates of corners of a building obtained after the application of the method of vector addition.

  15. Curvilinear steel elements in load-bearing structures of high-rise building spatial frames

    Directory of Open Access Journals (Sweden)

    Ibragimov Alexander

    2018-01-01

    Full Text Available The application of curvilinear elements in load-bearing metal structures of high-rise buildings supposes ensuring of their bearing capacity and serviceability. There may exist a great variety of shapes and orientations of such structural elements. In particular, it may be various flat curves of an open or closed oval profile such as circular or parabolic arch or ellipse. The considered approach implies creating vast internal volumes without loss in the load-bearing capacity of the frame. The basic concept makes possible a wide variety of layout and design solutions. The presence of free internal spaces of large volume in "skyscraper" type buildings contributes to resolving a great number of problems, including those of communicative nature. The calculation results confirm the basic assumptions.

  16. Curvilinear steel elements in load-bearing structures of high-rise building spatial frames

    Science.gov (United States)

    Ibragimov, Alexander; Danilov, Alexander

    2018-03-01

    The application of curvilinear elements in load-bearing metal structures of high-rise buildings supposes ensuring of their bearing capacity and serviceability. There may exist a great variety of shapes and orientations of such structural elements. In particular, it may be various flat curves of an open or closed oval profile such as circular or parabolic arch or ellipse. The considered approach implies creating vast internal volumes without loss in the load-bearing capacity of the frame. The basic concept makes possible a wide variety of layout and design solutions. The presence of free internal spaces of large volume in "skyscraper" type buildings contributes to resolving a great number of problems, including those of communicative nature. The calculation results confirm the basic assumptions.

  17. Earthquake response analysis of embedded reactor building considering soil-structure separation and nonlinearity of soil

    International Nuclear Information System (INIS)

    Ichikawa, T.; Hayashi, Y.; Nakai, S.

    1987-01-01

    In the earthquake response analysis for a rigid and massive structure as a nuclear reactor building, it is important to estimate the effect of soil-structure interaction (SSI) appropriately. In case of strong earthquakes, the nonlinearity, such as the wall-ground separation, the base mat uplift of sliding, makes the behavior of the soil-structure system complex. But, if the nuclear reactor building is embedded in a relatively soft ground with surface layer, the wall-ground separation plays the most important role in the response of soil-structure system. Because, it is expected that the base uplift and slide would be less significant due to the effect of the embedment, and the wall-ground friction is usually neglected in design. But, the nonlinearity of ground may have some effect on the wall-ground separation and the response of the structure. These problems have been studied by use of FEM. Others used joint elements between the ground and the structure which does not resist tensile force. Others studied the effect of wall-ground separation with non-tension springs. But the relationship between the ground condition and the effect of the separation has not been clarified yet. To clarify the effect the analyses by FE model and lumped mass model (sway-rocking model) are performed and compared. The key parameter is the ground profile, namely the stiffness of the side soil

  18. Effects of building structures on radiation doses from routine releases of radionuclides to the atmosphere

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1978-01-01

    Realistic assessments of radiation doses to the population from routine releases of radionuclides to the atmosphere require consideration of man's largely indoor environment. The effect of a building structure on radiation doses is described quantitatively by a dose reduction factor, which is the ratio of the dose to a reference individual inside a structure to the corresponding dose with no structure present. We have implemented models to estimate dose reduction factors for internal dose from inhaled radionuclides and for external photon dose from airborne and surface-deposited radionuclides. The models are particularly useful in radiological assessment applications, since dose reduction factors may readily be estimated for arbitrary mixtures and concentrations of radionuclides in the atmosphere and on the ground. The model for inhalation dose reduction factors accounts for radioactive decay, air ventilation into and out of the structure, and deposition of radionuclides on inside surfaces of the structure. External dose reduction factors are estimated using the point-kernel integration method including consideration of buildup in air and the walls of the building. The potential importance of deposition of radionuclides on inside surfaces of a structure on both inhalation and external dose reduction factors has been demonstrated. Model formulation and the assumptions used in the calculations are discussed. Results of model-parameter sensitivity studies and estimates of dose reduction factors for radionuclides occurring in routine releases from an LWR fuel reprocessing plant are presented. (author)

  19. Aircraft-crash-protected steel reactor building roof structure for the European market

    International Nuclear Information System (INIS)

    Posta, B.A.; Kadar, I.; Rao, A.S.

    1996-01-01

    This paper recommends the use of all steel roof structures for the reactor building of European Boiling Water Reactor (BWR) plants. This change would make the advanced US BWR designs more compatible with European requirements. Replacement of the existing concrete roof slab with a sufficiently thick steel plate would eliminate the concrete spelling resulting from a postulated aircraft crash, potentially damaging the drywell head or the spent fuel pool

  20. Detrimental effect of Air pollution, Corrosion on Building Materials and Historical Structures

    OpenAIRE

    N. Venkat Rao; M. Rajasekhar; Dr. G. Chinna Rao

    2016-01-01

    The economy of any country would be drastically changed if there were no corrosion. The annual cost of corrosion world wise is over 3 % of the worlds GDP. As pet the sources available, India losses $ 45 billion every year on account of corrosion of infrastructure, Industrial machinery and other historical heritage. Keeping this critical and alarming situation in view, this paper focuses on how all these forms of corrosion affect building materials and historical structures. It als...

  1. Deer herbivory reduces web-building spider abundance by simplifying forest vegetation structure

    Directory of Open Access Journals (Sweden)

    Elizabeth J. Roberson

    2016-09-01

    Full Text Available Indirect ecological effects are a common feature of ecological systems, arising when one species affects interactions among two or more other species. We examined how browsing by white-tailed deer (Odocoileus virginianus indirectly affected the abundance and composition of a web-building spider guild through their effects on the structure of the ground and shrub layers of northern hardwood forests. We examined paired plots consisting of deer-free and control plots in the Allegheny Plateau region Pennsylvania and Northern Highlands region of Wisconsin. We recorded the abundance of seven types of webs, each corresponding to a family of web-building spiders. We quantified vegetation structure and habitat suitability for the spiders by computing a web scaffold availability index (WSAI at 0.5 m and 1.0 m above the ground. At Northern Highlands sites, we recorded prey availability. Spider webs were twice as abundant in deer-free plots compared to control plots, while WSAI was 7–12 times greater in deerfree plots. Prey availability was lower in deer-free plots. With the exception of funnel web-builders, all spider web types were significantly more abundant in deer-free plots. Both deer exclusion and the geographic region of plots were significant predictors of spider community structure. In closed canopy forests with high browsing pressure, the low density of tree saplings and shrubs provides few locations for web-building spiders to anchor webs. Recruitment of these spiders may become coupled with forest disturbance events that increase tree and shrub recruitment. By modifying habitat structure, deer appear to indirectly modify arthropod food web interactions. As deer populations have increased in eastern North America over the past several decades, the effects of deer on web-building spiders may be widespread.

  2. Non-destructive evaluation of timber structures in a historical building of Tiradentes , MG

    Directory of Open Access Journals (Sweden)

    Luciana Barbosa de Abreu

    2013-09-01

    Full Text Available Problems related to the durability of wood are commonly found in historical buildings structures. Preservation and conservation resolutions must be adopted, in order to avoid losses and substitutions, which mischaracterize buildings. Non-destructive methods for detecting deterioration should be used in order to substantiate decisions and increase the longevity of historical heritage. This work was carried out in order to perform non-destructive essays to infer about the integrity of a beam and a pillar of the original construction of the Sobrado Ramalho, a historical building of the city of Tiradentes, MG. The equipments utilized were the Stress Wave Timer and resistograph. Samples of the elements were taken for analysis of density. The results showed that, in both structures, to calculate the dynamic modulus of elasticity, there was no significant difference for the application of stress wave timer on the alignments studied. There was no significant difference between the directions of application of the resistograph on the pillar, due to its apparent entirety and regular sessions, practically square, and to not being loaded eccentrically. In the case of the beam, there was significant difference, presumably because it has cracks in its traction line. The equipments, unknown by professionals of heritage conservation allow promising methodologies for inspection of timber structures in service.

  3. Seismic isolation structure for pool-type LMFBR - isolation building with vertically isolated floor for NSSS

    International Nuclear Information System (INIS)

    Sakurai, A.; Shiojiri, H.; Aoyagi, S.; Matsuda, T.; Fujimoto, S.; Sasaki, Y.; Hirayama, H.

    1987-01-01

    The NSSS isolation floor vibration characteristics were made clear. Especially, the side support bearing (rubber bearing) is effective for horizontal floor motion restraint and rocking motion control. Seismic isolation effects for responses of the reactor components can be sufficiently expected, using the vertical seismic isolation floor. From the analytical and experimental studies, the following has been concluded: (1) Seismic isolation structure, which is suitable for large pool-type LMFBR, were proposed. (2) Seismic response characteristics of the seismic isolation structure were investigated. It was made clear that the proposed seismic isolation (Combination of the isolated building and the isolated NSSS floor) was effective. (orig./HP)

  4. Odua Weston Jambi Hotel’s Structural Building Design with Prestressed Concrete Slab System Approach

    Science.gov (United States)

    Bayuaji, R.; Darmawan, M. S.; Rofiq, M. A.; Santoso, S. E.; Hardiyanto, E.

    2017-11-01

    Odua Weston Jambi Hotel is an eight-floor hotel and located in a prone to earth-quake area. This building used conventional concrete to its structural beam and column. This research’s purpose was to maximize the second-floor’s function by modifing its architectural design. Special Moment Resisting Frame System (SMRFS) approach was used in the structural design, referred to SNI 03-2847-2013 dan SNI 1726-2012 and to compensate the needs of a spacious hall without any column in the centre of the hall, so therefore, prestressed concrete plate is used to solve this problem.

  5. Modeling of the structural response to fire of a high-rise steel building

    DEFF Research Database (Denmark)

    Gentili, Filippo; Giuliani, Luisa; Bontempi, Franco

    2011-01-01

    Observations from the tests and the real fire investigations have consistently shown that the performance of a whole steel-framed building in fire is very different from the performance of its individual members (Usmani et al, 2000). In this context, it is of interest to investigate the failures...... problems due to the triggering of local mechanism should be overcome to this purpose. In this paper, a steel structure has been considered as case study and the response of the structural system to fire and fire effects has been investigated with the avail of a finite element commercial code. These kinds...

  6. Computational strategies for the automated design of RNA nanoscale structures from building blocks using NanoTiler.

    Science.gov (United States)

    Bindewald, Eckart; Grunewald, Calvin; Boyle, Brett; O'Connor, Mary; Shapiro, Bruce A

    2008-10-01

    One approach to designing RNA nanoscale structures is to use known RNA structural motifs such as junctions, kissing loops or bulges and to construct a molecular model by connecting these building blocks with helical struts. We previously developed an algorithm for detecting internal loops, junctions and kissing loops in RNA structures. Here we present algorithms for automating or assisting many of the steps that are involved in creating RNA structures from building blocks: (1) assembling building blocks into nanostructures using either a combinatorial search or constraint satisfaction; (2) optimizing RNA 3D ring structures to improve ring closure; (3) sequence optimisation; (4) creating a unique non-degenerate RNA topology descriptor. This effectively creates a computational pipeline for generating molecular models of RNA nanostructures and more specifically RNA ring structures with optimized sequences from RNA building blocks. We show several examples of how the algorithms can be utilized to generate RNA tecto-shapes.

  7. Computational strategies for the automated design of RNA nanoscale structures from building blocks using NanoTiler☆

    Science.gov (United States)

    Bindewald, Eckart; Grunewald, Calvin; Boyle, Brett; O’Connor, Mary; Shapiro, Bruce A.

    2013-01-01

    One approach to designing RNA nanoscale structures is to use known RNA structural motifs such as junctions, kissing loops or bulges and to construct a molecular model by connecting these building blocks with helical struts. We previously developed an algorithm for detecting internal loops, junctions and kissing loops in RNA structures. Here we present algorithms for automating or assisting many of the steps that are involved in creating RNA structures from building blocks: (1) assembling building blocks into nanostructures using either a combinatorial search or constraint satisfaction; (2) optimizing RNA 3D ring structures to improve ring closure; (3) sequence optimisation; (4) creating a unique non-degenerate RNA topology descriptor. This effectively creates a computational pipeline for generating molecular models of RNA nanostructures and more specifically RNA ring structures with optimized sequences from RNA building blocks. We show several examples of how the algorithms can be utilized to generate RNA tecto-shapes. PMID:18838281

  8. A study of building structural features associated with high indoor air concentrations of organochlorine termiticides.

    Science.gov (United States)

    Pisaniello, D L; Gun, R T; Tkaczuk, M N; Hann, C; Crea, J

    1993-09-01

    As part of a two-year study of post-treatment residential exposure to the termiticide, aldrin, the building structural features of ten houses with crawl-space-type floors were assessed by an independent inspector. Building attributes recorded on a checklist included the age of the dwelling, room characteristics, floor details and the nature of subfloor ventilation. At the end of each inspection, the inspector, who was blinded to data on airborne aldrin concentrations, provided a rating of expected indoor air contamination. Several of the building attributes, including the age of the house, the area of exterior subfloor vents, as well as the inspector's rating, were significantly correlated with airborne aldrin values. No single building variable, however, was highly correlated with every measure of aldrin concentration over a 12-month period. The observed data are consistent with poor subfloor ventilation and a 'leaky' floor being important contributors to indoor air pollution. It is recommended that pest control companies advise householders about any obvious floor and ventilation deficiencies before soil treatment work is undertaken. Pesticide exposure (by analogy with geological radon exposure) may be reduced by sealing gaps in floors and/or by improving subfloor ventilation.

  9. Neutron radiography for the characterization of porous structure in degraded building stones

    International Nuclear Information System (INIS)

    Barone, G; Mazzoleni, P; Raneri, S; Crupi, V; Longo, F; Majolino, D; Venuti, V; Teixeira, J

    2014-01-01

    As it is well known, the porous structure of stones can change due to different degradation processes that modify the characteristics of freshly quarried blocks. Their knowledge is fundamental for predicting the behavior of stones and the efficacy of conservative treatments. In this context, neutron radiography is a useful tool not only to visualize the structure of porous materials, but also to evaluate the degree of degradation and surface modifications resulting from weathering processes. Furthermore, since thermal neutrons suffer a strong attenuation by hydrogen, this technique is effective in order to investigate the amount of absorbed water in building materials. In the present work, we report a neutron radiography investigation of limestones cropping out in the South-Eastern Sicily and widely used as building stones in Baroque monuments of the Noto Valley. The analyzed samples have been submitted to cyclic salt crystallization that simulate degradation processes acting in exposed stones of buildings. The obtained results demonstrate the interest of neutron radiography to better understand deterioration processes in limestones and to acquire information useful for restoration projects

  10. Study on reactor building structure using ultrahigh strength materials - Part 9: Summary of the study

    International Nuclear Information System (INIS)

    Tanaka, H.; Odajima, M.; Irino, K.; Hashiba, T.

    1993-01-01

    Considerations for longevity of nuclear facilities and ease of decommissioning are of great importance for future nuclear power plants. To this end, a concept of an optimal structural concept for nuclear reactor buildings has been studied: the main feature of this concept is to utilize large-sized, light weight prefabricated members with ultrahigh strength materials. The following two items have been selected to study the prospective structure: (1) Applicability of ultrahigh strength materials for reinforced concrete shear walls (2) Construction using large sized prefabricated members As the first step (1), material and structural tests using ultrahigh strength materials, and the subsequent analysis of those tests for reinforced concrete shear walls, has been conducted. The positive results of this study show a bright future for the use of ultrahigh strength materials for the reinforced concrete shear walls of nuclear reactor buildings. As the second step (2), tests on a mixed structure with precasted members have been conducted. Our results positively suggest the use of these materials and methods to improve prospective nuclear power plants. (author)

  11. Base Isolation for Seismic Retrofitting of a Multiple Building Structure: Evaluation of Equivalent Linearization Method

    Directory of Open Access Journals (Sweden)

    Massimiliano Ferraioli

    2016-01-01

    Full Text Available Although the most commonly used isolation systems exhibit nonlinear inelastic behaviour, the equivalent linear elastic analysis is commonly used in the design and assessment of seismic-isolated structures. The paper investigates if the linear elastic model is suitable for the analysis of a seismically isolated multiple building structure. To this aim, its computed responses were compared with those calculated by nonlinear dynamic analysis. A common base isolation plane connects the isolation bearings supporting the adjacent structures. In this situation, the conventional equivalent linear elastic analysis may have some problems of accuracy because this method is calibrated on single base-isolated structures. Moreover, the torsional characteristics of the combined system are significantly different from those of separate isolated buildings. A number of numerical simulations and parametric studies under earthquake excitations were performed. The accuracy of the dynamic response obtained by the equivalent linear elastic model was calculated by the magnitude of the error with respect to the corresponding response considering the nonlinear behaviour of the isolation system. The maximum displacements at the isolation level, the maximum interstorey drifts, and the peak absolute acceleration were selected as the most important response measures. The influence of mass eccentricity, torsion, and high-modes effects was finally investigated.

  12. Pre-Cloak Comic Superheroes: Tools for the Empowerment of Children

    Directory of Open Access Journals (Sweden)

    Chris Fradkin

    2016-09-01

    Full Text Available This note explores the notion of comic superheroes as tools for the empowerment of children. The author details interventions in Rwanda and Brazil, and their different usages of superheroes. With a focus on the superhero’s pre-cloak stage—the stage prior to their employing superpowers—the author offers glimpses of current work in progress to help therapists empower orphaned children. While this area of research is at an early stage, its potential among health professionals is growing. Thus the comic superhero may be more than celluloid, as health professionals learn to use his superpowers.

  13. Seismic resistance design of nuclear power plant building structures in Japan

    International Nuclear Information System (INIS)

    Kitano, Takehito

    1997-01-01

    Japan is one of the countries where earthquakes occur most frequently in the world and has incurred a lot of disasters in the past. Therefore, the seismic resistance design of a nuclear power plant plays a very important role in Japan. This report describes the general method of seismic resistance design of a nuclear power plant giving examples of PWR and BWR type reactor buildings in Japan. Nuclear facilities are classified into three seismic classes and is designed according to the corresponding seismic class in Japan. Concerning reactor buildings, the short-term allowable stress design is applied for the S1 seismic load and it is confirmed that the structures have a safety margin against the S2 seismic load. (J.P.N.)

  14. Seismic resistance design of nuclear power plant building structures in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kitano, Takehito [Kansai Electric Power Co., Inc., Osaka (Japan)

    1997-03-01

    Japan is one of the countries where earthquakes occur most frequently in the world and has incurred a lot of disasters in the past. Therefore, the seismic resistance design of a nuclear power plant plays a very important role in Japan. This report describes the general method of seismic resistance design of a nuclear power plant giving examples of PWR and BWR type reactor buildings in Japan. Nuclear facilities are classified into three seismic classes and is designed according to the corresponding seismic class in Japan. Concerning reactor buildings, the short-term allowable stress design is applied for the S1 seismic load and it is confirmed that the structures have a safety margin against the S2 seismic load. (J.P.N.)

  15. Simquake 3: Seismic interactions between building structures and rock-socketed foundations: Final report

    International Nuclear Information System (INIS)

    Howard, G.E.; Chitty, D.E.; Oleck, R.F.

    1988-04-01

    It has long been recognized that soil-structure interaction can significantly influence the earthquake response of massive structures such as nuclear power plant reactor buildings. The linear analysis methods that are widely used to model interaction phenomena can result in often unrecognized safety margins in design for earthquake excitation. Use of improved interaction models which capture nonlinear characteristics of interaction---such as energy dissipation and significant changes in stiffness---can provide realistic predictions of the earthquake loads imposed on nuclear power plant structures and equipment, supplying an improved basis for seismic design review. This report documents the results of a research effort investigating the soil-structure (or structure-media) interaction of reinforced concrete structures founded in backfilled rock sockets. The objectives of the research, which included field testing with semi-scale structural models, were: to examine the influence of the backfilled socket on structural dynamic response; and to develop an experimental data base for the benchmarking of computer simulation procedures

  16. D Visualization of a Timber Frame Historic Building: Partite Usage and its Impact on the Structural System

    Science.gov (United States)

    Günay, S.

    2017-08-01

    Throughout their lifetime, historic buildings might be altered for different kind of usage for different purposes. If this new function or new usage requires utilization of the building in separate units, this separation might affect the historic building's functionality and structure and as a result its overall condition. Yorguc Pasa Mansion conservation project was prepared as a part of the Middle East Technical University (METU) Master's Program in Documentation and Conservation of Historic Monuments and Sites for the historic Yorguc Pasa Mansion. The mansion is a 19th century Ottoman Period timber frame building in Amasya, a Black Sea Region city in Turkey that has traces from different civilizations such as Hittites, Greeks, Romans and Ottomans. This paper aims to discuss the affects of the partite usage on structural conditions of timber frame buildings with the case study of Amasya Yorguc Pasa Mansion through the 3D visualized structural systems.

  17. Aspects of mast building and the fine structure of “amphipod silk” glands in Dyopedos bispinis (Amphipoda, Dulichiidae)

    NARCIS (Netherlands)

    Neretin, N.Y.; Zhadan, A.E.; Tzetlin, A.B.

    2017-01-01

    In the present study, we investigated the biology of Dyopedos bispinis, a mast-building amphipod that is abundant near the N. Pertsov White Sea Biological Station. To examine the peculiarities of mast building in Dyopedos bispinis, we studied the social structure of individuals inhabiting the masts

  18. Effect of modeling of super-structure on the behaviour of reactor building raft

    International Nuclear Information System (INIS)

    Mondal, A.; Singh, A.K.; Roy, Raghupati; Verma, U.S.P.; Warudkar, A.S.

    2003-01-01

    The behaviour of the reactor building raft was studied when the stiffness of the super-structural elements is included in the analysis as compared to the results of conventional analysis ignoring the stiffness of the super-structural elements. The effect of the stiffness of the super-structures on the loss of contact of the raft under seismic environment was also investigated. In order to study the effect of horizontal springs on the behaviour of the raft particularly near the stressing gallery under seismic environment, a separate study has been carried out considering a 3D model consisting of solid elements supported on both horizontal and vertical springs. The model was analysed for all the forces applied at the top of the raft and the analysis results were compared with those of shell model. The following conclusions are drawn: (i) Idealisation of the reactor building raft using shell elements is adequate for estimating the design forces/moments on the raft. The design forces/moments obtained from FE model consisting of solid elements closely matches with those obtained from FE model with shell elements. Idealisation of the RB raft using shell elements will also reduce the problem size and the related computational efforts. (ii) The stiffness of the super-structure has significant effect on the behaviour of the raft. Consideration of the stiffness of the super structure reduces the design forces/moments significantly and hence, modelling of the stiffness of the super structure is necessary for economical design. (iii) Modelling of horizontal stiffness of the raft in terms of horizontal springs at the interface of the raft and the rock does not have significant effect on the behaviour of the raft and as such, is not required to be considered in the FE model. However, it is necessary to ensure adequate factor of safety against the overall stability of the raft

  19. Rainfall-induced landslide vulnerability Assessment in urban area reflecting Urban structure and building characteristics

    Science.gov (United States)

    Park, C.; Cho, M.; Lee, D.

    2017-12-01

    Landslide vulnerability assessment methodology of urban area is proposed with urban structure and building charateristics which can consider total damage cost of climate impacts. We used probabilistic analysis method for modeling rainfall-induced shallow landslide susceptibility by slope stability analysis and Monte Carlo simulations. And We combined debris flows with considering spatial movements under topographical condition and built environmental condition. Urban vulnerability of landslide is assessed by two categories: physical demages and urban structure aspect. Physical vulnerability is related to buildings, road, other ubran infra. Urban structure vulnerability is considered a function of the socio-economic factors, trigger factor of secondary damage, and preparedness level of the local government. An index-based model is developed to evaluate the life and indirect damage under landslide as well as the resilience ability against disasters. The analysis was performed in a geographic information system (GIS) environment because GIS can deal efficiently with a large volume of spatial data. The results of the landslide susceptibility assessment were compared with the landslide inventory, and the proposed approach demonstrated good predictive performance. The general trend found in this study indicates that the higher population density areas under a weaker fiscal condition that are located at the downstream of mountainous areas are more vulnerable than the areas in opposite conditions.

  20. Japanese contributions to containment structure, assembly and maintenance and reactor building for ITER

    International Nuclear Information System (INIS)

    Shibanuma, Kiyoshi; Honda, Tsutomu; Kanamori, Naokazu

    1991-06-01

    Joint design work on Conceptual Design Activity of International Thermonuclear Experimental Reactor (ITER) with four parties, Japan, the United States, the Soviet Union and the European Community began in April 1988 and was successfully completed in December 1990. In Japan, the home team was established in wide range of collaboration between JAERI and national institute, universities and heavy industries. The Fusion Experimental Reactor (FER) Team at JAERI is assigned as a core of the Japanese home team to support the joint Team activity and mainly conducted the design and R and D in the area of containment structure, remote handling and plant system. This report mainly describes the Japanese contribution on the ITER containment structure, remote handling and reactor building design. Main areas of contributions are vacuum vessel, attaching locks, electromagnetic analysis, cryostat, port and service line layout for containment structure, in-vessel handling equipment design and analysis, blanket handling equipment design and related short term R and D for assembly and maintenance, and finally reactor building design and analysis based on the equipment and service line layout and components flow during assembly and maintenance. (author)

  1. Life-Cycle Assessment of Seismic Retrofit Strategies Applied to Existing Building Structures

    Directory of Open Access Journals (Sweden)

    Umberto Vitiello

    2016-12-01

    Full Text Available In the last few years, the renovation and refurbishment of existing buildings have become the main activities of the construction industry. In particular, many studies have recently focused on the mechanical and energy performances of existing retrofitted/refurbished facilities, while some research has addressed the environmental effects of such operations. The present study aims to assess the environmental impact of some retrofit interventions on an existing reinforced concrete (RC building. Once the structural requirements have been satisfied and the environmental effects of these retrofit solutions defined, the final purpose of this study is to identify the most environmentally sustainable retrofit strategy. The environmental impact of the structural retrofit options is assessed using a life-cycle assessment (LCA. This paper sets out a systematic approach that can be adopted when choosing the best structural retrofit option in terms of sustainability performance. The final aim of the study is to also provide a tool for researchers and practitioners that reflects a deep understanding of the sustainability aspects of retrofit operations and can be used for future researches or practical activities.

  2. Seismic Response of Steel Braced Building Frame Considering Soil Structure Interaction (SSI): An Experimental Study

    Science.gov (United States)

    Hirave, Vivek; Kalyanshetti, Mahesh

    2018-02-01

    Conventional fixed-base analysis ignoring the effect of soil-flexibility may result in unsafe design. Therefore, to evaluate the realistic behavior of structure the soil structure interaction (SSI) effect shall be incorporated in the analysis. In seismic analysis, provision of bracing system is one of the important option for the structure to have sufficient strength with adequate stiffness to resist lateral forces. The different configuration of these bracing systems alters the response of buildings, and therefore, it is important to evaluate the most effective bracing systems in view point of stability against SSI effect. In present study, three RC building frames, G+3, G+5 and G+7 and their respective scaled down steel model with two types of steel bracing system incorporating the effect of soil flexibility is considered for experimental and analytical study. The analytical study is carried out using Elastic continuum approach and the experimental study is carried out using Shake Table. The influence of SSI on various seismic parameters is presented. The study reveals that, steel bracing system is beneficial to control SSI effect and it is observed that V bracing is more effective, in resisting seismic load considering SSI.

  3. Impact of structural parameters on the radon exhalation of building materials: Preliminary study

    International Nuclear Information System (INIS)

    Roelofs, L.M.M.

    1993-01-01

    Samples of mortar and sand-lime pieces with different percentages of fly ash are hardened at different relative humidities. The porosity distribution, the moisture and the radon exhalation of these samples are determined. Based on the data of the above-mentioned analyses, the thickness of the adsorbed water layer in the water-filled pores is estimated. The correlation between the structural parameters and the radon exhalation is investigated. If the radon exhalation process can be modelled, the radiation risk of applying fly ash in building materials can be controlled or reduced. The results do not yet show a clear indication. The applied methods have to be considered in more detail

  4. 3-dimensional finite element modelling of reactor building internal structure for static analysis

    International Nuclear Information System (INIS)

    Joshi, M.H.; Reddy, V.J.; Kushwaha, H.S.; Reddy, G.R.; Karandikar, G.V.

    1991-01-01

    a) Thin shell element gives fairly accurate results when compared to 3-D Brick element for the type of structure and loading in Reactor Building. b) The maximum element size is fixed from model 3(c) i.e. 2.0 m. c) Openings with size smaller than 0.5 m can be neglected without affecting the results very much. d) For any such problem, the methodology described in this paper can be used to take rational decisions which will ensure reasonable accuracy. (author)

  5. Seismic transmission tomography: determination of the elastic properties of building structures (some examples

    Directory of Open Access Journals (Sweden)

    E. Cardarelli

    2000-06-01

    Full Text Available This paper is a general review on seismic transmission tomography considering data acquisition and processing. Some questions on linear and non linear inversions are tackled, and advice given on the choice of the best damping factor. Taking into account prediction matrices we show that it is possible to point out the best distribution of sensors and shot points in terms of resolution and stability of system. Then two examples in which seismic tomography was used are described concerning the determination of elastic characteristics of building structures.

  6. Constructive fire protection of steel corrugated beams of buildings and other structures

    Directory of Open Access Journals (Sweden)

    Ilyin Nikolay

    2017-01-01

    Full Text Available The research introduces a methodology of establishing indicators of fire safety of a building in relation to a guaranteed duration of steel fire-proof corrugated beams resistance in conditions of standard fire tests. Indicators of fire safety are also established in the assessment of design limits of steel fire-proof corrugated beams during design process, construction or maintenance of the building as well as in reducing economic costs when testing steel structures for fire resisting property. The suggested methodology introduces the system of actions aimed to design constructive fire protection of steel corrugated beams of buildings. Technological effect is achieved by conducting firing tests of steel construction by non-destructive methods; the evaluation of fire resistance of fire-proof elements of corrugated beams (corrugated web, upper and lower shelves is identified by the least fire-proof element of a welded I-beam. In this methodology fire resistance duration of the constituent elements of a welded I-beam with account of its fire protection ability is described with an analytic function taken as variables. These variables are intensity strength of stresses and the degree of fire protection of a compound element.

  7. Analytical Model of Underground Train Induced Vibrations on Nearby Building Structures in Cameroon: Assessment and Prediction

    Directory of Open Access Journals (Sweden)

    Lezin Seba MINSILI

    2013-11-01

    Full Text Available The purpose of this research paper was to assess and predict the effect of vibrations induced by an underground railway on nearby-existing buildings prior to the construction of projected new railway lines of the National Railway Master Plan of Cameroon and after upgrading of the railway conceded to CAMRAIL linking the two most densely populated cities of Cameroon: Douala and Yaoundé. With the source-transmitter-receiver mathematical model as the train-soil-structure interaction model, taking into account sub-model parameters such as type of the train-railway system, typical geotechnical conditions of the ground and the sensitivity of the nearby buildings, the analysis is carried out over the entire system using the dynamic finite element method in the time domain. This subdivision of the model is a powerful tool that allows to consider different alternatives of sub-models with different characteristics, and thus to determine any critical excessive vibration impact. Based on semi-empirical analytical results obtained from presented models, the present work assesses and predicts characteristics of traffic-induced vibrations as a function of time duration, intensity and vehicle speed, as well as their influence on buildings at different levels.

  8. An investigation of soil-structure interaction effects observed at the MIT Green Building

    Science.gov (United States)

    Taciroglu, Ertugrul; Çelebi, Mehmet; Ghahari, S. Farid; Abazarsa, Fariba

    2016-01-01

    The soil-foundation impedance function of the MIT Green Building is identified from its response signals recorded during an earthquake. Estimation of foundation impedance functions from seismic response signals is a challenging task, because: (1) the foundation input motions (FIMs) are not directly measurable, (2) the as-built properties of the super-structure are only approximately known, and (3) the soil-foundation impedance functions are inherently frequency-dependent. In the present study, aforementioned difficulties are circumvented by using, in succession, a blind modal identification (BMID) method, a simplified Timoshenko beam model (TBM), and a parametric updating of transfer functions (TFs). First, the flexible-base modal properties of the building are identified from response signals using the BMID method. Then, a flexible-base TBM is updated using the identified modal data. Finally, the frequency-dependent soil-foundation impedance function is estimated by minimizing the discrepancy between TFs (of pairs instrumented floors) that are (1) obtained experimentally from earthquake data and (2) analytically from the updated TBM. Using the fully identified flexible-base TBM, the FIMs as well as building responses at locations without instruments can be predicted, as demonstrated in the present study.

  9. An Improved Privacy-Preserving Framework for Location-Based Services Based on Double Cloaking Regions with Supplementary Information Constraints

    Directory of Open Access Journals (Sweden)

    Li Kuang

    2017-01-01

    Full Text Available With the rapid development of location-based services in the field of mobile network applications, users enjoy the convenience of location-based services on one side, while being exposed to the risk of disclosure of privacy on the other side. Attacker will make a fierce attack based on the probability of inquiry, map data, point of interest (POI, and other supplementary information. The existing location privacy protection techniques seldom consider the supplementary information held by attackers and usually only generate single cloaking region according to the protected location point, and the query efficiency is relatively low. In this paper, we improve the existing LBSs system framework, in which we generate double cloaking regions by constraining the supplementary information, and then k-anonymous task is achieved by the cooperation of the double cloaking regions; specifically speaking, k dummy points of fixed dummy positions in the double cloaking regions are generated and the LBSs query is then performed. Finally, the effectiveness of the proposed method is verified by the experiments on real datasets.

  10. Elfin: An algorithm for the computational design of custom three-dimensional structures from modular repeat protein building blocks.

    Science.gov (United States)

    Yeh, Chun-Ting; Brunette, T J; Baker, David; McIntosh-Smith, Simon; Parmeggiani, Fabio

    2018-02-01

    Computational protein design methods have enabled the design of novel protein structures, but they are often still limited to small proteins and symmetric systems. To expand the size of designable proteins while controlling the overall structure, we developed Elfin, a genetic algorithm for the design of novel proteins with custom shapes using structural building blocks derived from experimentally verified repeat proteins. By combining building blocks with compatible interfaces, it is possible to rapidly build non-symmetric large structures (>1000 amino acids) that match three-dimensional geometric descriptions provided by the user. A run time of about 20min on a laptop computer for a 3000 amino acid structure makes Elfin accessible to users with limited computational resources. Protein structures with controlled geometry will allow the systematic study of the effect of spatial arrangement of enzymes and signaling molecules, and provide new scaffolds for functional nanomaterials. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Structural and compositional characterization of the adhesive produced by reef building oysters.

    Science.gov (United States)

    Alberts, Erik M; Taylor, Stephen D; Edwards, Stephanie L; Sherman, Debra M; Huang, Chia-Ping; Kenny, Paul; Wilker, Jonathan J

    2015-04-29

    Oysters have an impressive ability to overcome difficulties of life within the stressful intertidal zone. These shellfish produce an adhesive for attaching to each other and building protective reef communities. With their reefs often exceeding kilometers in length, oysters play a major role in balancing the health of coastal marine ecosystems. Few details are available to describe oyster adhesive composition or structure. Here several characterization methods were applied to describe the nature of this material. Microscopy studies indicated that the glue is comprised of organic fiber-like and sheet-like structures surrounded by an inorganic matrix. Phospholipids, cross-linking chemistry, and conjugated organics were found to differentiate this adhesive from the shell. Symbiosis in material synthesis could also be present, with oysters incorporating bacterial polysaccharides into their adhesive. Oyster glue shows that an organic-inorganic composite material can provide adhesion, a property especially important when constructing a marine ecosystem.

  12. Structural Risk Assessment and Mitigation for Low- to Mid-Rise Residential Buildings in China

    Directory of Open Access Journals (Sweden)

    Kasim A. Korkmaz

    2017-07-01

    Full Text Available China has experienced major earthquakes recently. The 2014 Ludian earthquake struck Ludian County, Yunnan, (Mw = 6.1 on 3 August, 2014. On April 20th 2013, Ya’an earthquake (Mw = 6.9, on April 14th 2010, Qinghai earthquake (Mw = 7.1, on July 9th 2009, Yunnan earthquake (Mw = 6.0, and on May 12th 2008, Sichuan earthquake (Mw = 7.9 struck China. Among these disasters, the most devastating, the Sichuan earthquake, resulted in the collapse of 5 million buildings and damage to more than 21 million. Human loss was also high with over 60,000 people dead, 360,000 injured, and more than 14 million people displaced. South-west China lies in an area that is prone to earthquakes. In 1970, a magnitude 7.7 earthquake in Yunnan with 15,000 lost. This study presents a detailed risk assessment for a structural risk assessment and mitigation for low- to mid-rise residential buildings for China. The risk assessment, through seismic hazard assessment approaches, evaluates the impact of the disasters for integrated structural health monitoring. Among the results of the investigation, relations and links between safety and risk are defined.

  13. TEACHING OPTIMIZATION OF STUDENTS AT DESIGN OF BUILDINGS AND STRUCTURES FOUNDATIONS

    Directory of Open Access Journals (Sweden)

    MISURA Lid. V.

    2016-04-01

    Full Text Available Raising of problem. According to world statistics, more than 75 % of all violations of the normal operation of buildings and structures is due to deficiencies in the design, construction and operation of bases and foundations [1]. The costs to eliminate these negative effects can be compared only with the initial cost of construction, it speaks about the relevance of teaching subjects related to the design of foundations. On the other hand increased demands on the students' knowledge, raises the amount of information that needs to absorb at constant periods of instruction, which makes the current process optimization study of these disciplines. Purpose. The aim of the article is to present the software package that allows to facilitate and accelerate the calculation and check the parameters of foundations and bases for the design of buildings and structures. The software product is designed as an educational complex, which allows the student to help with the calculations in different levels of difficulty and test his knowledge. Conclusion. The program complex, which consists of a program for dimensioning the foundations, the program for calculating the parameters of the bases, of the database. It is confirmed stable operation of the school complex (the program, measures were taken to test the program, helped to make it stable. The training complex is designed only for shallow foundations, so the work will be continued.

  14. Structural Model for the Effects of Perceived Indoor Work Environment on Sick Building Syndrome and Stress

    Directory of Open Access Journals (Sweden)

    Abdullah Nor Hazana

    2016-01-01

    Full Text Available Sick Building syndrome (SBS and stress have a prevalent influence on organizational productivity and competitiveness. Unhealthy employees not only tend to have high medical leaves but also low productivity due to ailments and discomforts. Studies that investigate the effects of indoor work environment on Sick Building Syndrome (SBS have yielded mixed results while their effect on stress has not been empirically established. Furthermore, studies that simultaneously investigate both SBS and stress are almost non-existent. Thus, this study aimed to study the effects of perceived indoor work environment on SBS and stress and the link between SBS and stress. A cross-sectional survey participated by 598 employees from various industries was conducted from September to October 2015. Data were analyzed using Partial Least Square Structural Equation Modeling (PLS-SEM to assess both the measurement model and the path structure. The results suggest that indoor work environment has significant yet the weak effect on SBS while it has no effect on stress. However, SBS has a strong significant relationship with stress. The implication of this study on the importance of conducive indoor work environment is discussed with suggestions for future studies.

  15. Semiexperimental equilibrium structures for building blocks of organic and biological molecules: the B2PLYP route.

    Science.gov (United States)

    Penocchio, Emanuele; Piccardo, Matteo; Barone, Vincenzo

    2015-10-13

    The B2PLYP double hybrid functional, coupled with the correlation-consistent triple-ζ cc-pVTZ (VTZ) basis set, has been validated in the framework of the semiexperimental (SE) approach for deriving accurate equilibrium structures of molecules containing up to 15 atoms. A systematic comparison between new B2PLYP/VTZ results and several equilibrium SE structures previously determined at other levels, in particular B3LYP/SNSD and CCSD(T) with various basis sets, has put in evidence the accuracy and the remarkable stability of such model chemistry for both equilibrium structures and vibrational corrections. New SE equilibrium structures for phenylacetylene, pyruvic acid, peroxyformic acid, and phenyl radical are discussed and compared with literature data. Particular attention has been devoted to the discussion of systems for which lack of sufficient experimental data prevents a complete SE determination. In order to obtain an accurate equilibrium SE structure for these situations, the so-called templating molecule approach is discussed and generalized with respect to our previous work. Important applications are those involving biological building blocks, like uracil and thiouracil. In addition, for more general situations the linear regression approach has been proposed and validated.

  16. The development of an expert system for finding fragility curves of building structural systems in the preliminary design stage

    International Nuclear Information System (INIS)

    Yee, L.Y.; Okrent, D.

    1987-01-01

    This research is a starting point for the development of an expert system for determining seismic fragility curves of structural systems in a nuclear power plant or conventional building at the preliminary design stage. The resulting system assists an engineer with moderate engineering background and limited reliability knowledge to analyze the failure functions of building structures. It simulates the performance of an expert in identifying the potential failure modes and their variabilities for a structure of interest. On reviewing the methodology of seismic fragility evaluation for existing building structures in the nuclear power plant industry, one finds that the investigation process starts with the identification of critical components or substructures, whose failures result in the functional failure of safety related equipment or the failure of structural integrity itself, and follows with complicated numerical analyses to estimate the capacity functions associated with the limit states of these components or substructures

  17. Review of the use of phase change materials (PCMs in buildings with reinforced concrete structures

    Directory of Open Access Journals (Sweden)

    Pons, O.

    2014-09-01

    Full Text Available Phase change materials are capable of storing and releasing energy in the form of heat in determined temperature ranges, so to increase a building’s thermal inertia, stabilize its indoor temperatures and reduce its energetic demand. Therefore, if we used these materials we could have more energetically efficient buildings. Nevertheless, are these materials most appropriate to be used in buildings? Could the incorporation of phase change materials in buildings with concrete structures be generalized? This article aims to carry out a review of these phase change materials from construction professionals’ points of view, study their applications for buildings with reinforced concrete structures and the key points for these applications, draw conclusions and provide recommendations useful for all professionals within the sector who are considering the application of these materials.Los materiales de cambio de fase son capaces de almacenar y liberar energía en forma de calor en un determinando rango de temperaturas, y así aumentar la inercia térmica de un edificio, estabilizar las temperaturas en el interior y reducir la demanda energética. En consecuencia, si utilizáramos estos materiales podríamos tener un parque de edificios más eficientes energéticamente. No obstante, ¿estos materiales son apropiados para usarse en edificios? ¿Se podría generalizar la incorporación de materiales de cambio de fase en edificios con estructuras de hormigón? Este artículo tiene como objetivos hacer una revisión del estado del arte de estos materiales de cambio de fase desde el punto de vista de los profesionales de la construcción, estudiar las aplicaciones en edificios con estructuras de hormigón armado y los puntos clave para estas aplicaciones, extraer conclusiones y recomendaciones útiles para los profesionales del sector que se planteen la utilización de estos materiales.

  18. Accurate facade feature extraction method for buildings from three-dimensional point cloud data considering structural information

    Science.gov (United States)

    Wang, Yongzhi; Ma, Yuqing; Zhu, A.-xing; Zhao, Hui; Liao, Lixia

    2018-05-01

    Facade features represent segmentations of building surfaces and can serve as a building framework. Extracting facade features from three-dimensional (3D) point cloud data (3D PCD) is an efficient method for 3D building modeling. By combining the advantages of 3D PCD and two-dimensional optical images, this study describes the creation of a highly accurate building facade feature extraction method from 3D PCD with a focus on structural information. The new extraction method involves three major steps: image feature extraction, exploration of the mapping method between the image features and 3D PCD, and optimization of the initial 3D PCD facade features considering structural information. Results show that the new method can extract the 3D PCD facade features of buildings more accurately and continuously. The new method is validated using a case study. In addition, the effectiveness of the new method is demonstrated by comparing it with the range image-extraction method and the optical image-extraction method in the absence of structural information. The 3D PCD facade features extracted by the new method can be applied in many fields, such as 3D building modeling and building information modeling.

  19. Experimental validation of an ultra-thin metasurface cloak for hiding a metallic obstacle from an antenna radiation at low frequencies

    Science.gov (United States)

    Teperik, Tatiana V.; Burokur, Shah Nawaz; de Lustrac, André; Sabanowski, Guy; Piau, Gérard-Pascal

    2017-07-01

    We demonstrate numerically and experimentally an ultra-thin (≈ λ/240) metasurface-based invisibility cloak for low frequency antenna applications. We consider a monopole antenna mounted on a ground plane and a cylindrical metallic obstacle of diameter smaller than the wavelength located in its near-field. To restore the intrinsic radiation patterns of the antenna perturbed by this obstacle, a metasurface cloak consisting simply of a metallic patch printed on a dielectric substrate is wrapped around the obstacle. Using a finite element method based commercial electromagnetic solver, we show that the radiation patterns of the monopole antenna can be restored completely owing to electromagnetic modes of the resonant cavity formed between the patch and obstacle. The metasurface cloak is fabricated, and the concept is experimentally demonstrated at 125 MHz. Performed measurements are in good agreement with numerical simulations, verifying the efficiency of the proposed cloak.

  20. Three-dimensional segmentation and skeletonization to build an airway tree data structure for small animals

    International Nuclear Information System (INIS)

    Chaturvedi, Ashutosh; Lee, Zhenghong

    2005-01-01

    Quantitative analysis of intrathoracic airway tree geometry is important for objective evaluation of bronchial tree structure and function. Currently, there is more human data than small animal data on airway morphometry. In this study, we implemented a semi-automatic approach to quantitatively describe airway tree geometry by using high-resolution computed tomography (CT) images to build a tree data structure for small animals such as rats and mice. Silicon lung casts of the excised lungs from a canine and a mouse were used for micro-CT imaging of the airway trees. The programming language IDL was used to implement a 3D region-growing threshold algorithm for segmenting out the airway lung volume from the CT data. Subsequently, a fully-parallel 3D thinning algorithm was implemented in order to complete the skeletonization of the segmented airways. A tree data structure was then created and saved by parsing through the skeletonized volume using the Python programming language. Pertinent information such as the length of all airway segments was stored in the data structure. This approach was shown to be accurate and efficient for up to six generations for the canine lung cast and ten generations for the mouse lung cast

  1. Automated global structure extraction for effective local building block processing in XCS.

    Science.gov (United States)

    Butz, Martin V; Pelikan, Martin; Llorà, Xavier; Goldberg, David E

    2006-01-01

    Learning Classifier Systems (LCSs), such as the accuracy-based XCS, evolve distributed problem solutions represented by a population of rules. During evolution, features are specialized, propagated, and recombined to provide increasingly accurate subsolutions. Recently, it was shown that, as in conventional genetic algorithms (GAs), some problems require efficient processing of subsets of features to find problem solutions efficiently. In such problems, standard variation operators of genetic and evolutionary algorithms used in LCSs suffer from potential disruption of groups of interacting features, resulting in poor performance. This paper introduces efficient crossover operators to XCS by incorporating techniques derived from competent GAs: the extended compact GA (ECGA) and the Bayesian optimization algorithm (BOA). Instead of simple crossover operators such as uniform crossover or one-point crossover, ECGA or BOA-derived mechanisms are used to build a probabilistic model of the global population and to generate offspring classifiers locally using the model. Several offspring generation variations are introduced and evaluated. The results show that it is possible to achieve performance similar to runs with an informed crossover operator that is specifically designed to yield ideal problem-dependent exploration, exploiting provided problem structure information. Thus, we create the first competent LCSs, XCS/ECGA and XCS/BOA, that detect dependency structures online and propagate corresponding lower-level dependency structures effectively without any information about these structures given in advance.

  2. USING MATRIX METHODS OF PORTFOLIO ANALYSIS IN DESIGNING VERTICAL-INTEGRATED BUILDING STRUCTURE

    Directory of Open Access Journals (Sweden)

    Rakytska S.

    2018-01-01

    Full Text Available Introduction. Ensuring productive functioning of corporations requires assessment and management decisions in terms of choosing effective areas of its activities. Purpose. Investigation of the possibilities of using matrix methods in the formation of a business portfolio in order to create a vertically-integrated structure in the construction complex. Results. Portfolio analysis is an effective tool, first of all, for functionally flexible, “many grocery” companies, who have the opportunity to quickly make changes to their business portfolio. For the production of the final construction product, you need the entire technological chain – from the supplier of primary raw materials, to the implementation and further maintenance of finished products. The strategy of the integrated structure is designed to: coordinate the objectives of the merged enterprises, determine the degree of their interaction, maximize the effect of the integration of business entities, develop ways to react newly formed corporation to changes taking place in the external environment, determine the most effective way of its development time, to ensure the competitive advantages of an integrated structure. The construction of a complex multi-level corporation in a building complex requires the development of a certain algorithm of action, which will ensure the optimality of the newly created structure and effective functioning.

  3. Acoustic cloaking by a near-zero-index phononic crystal

    KAUST Repository

    Zheng, Li-Yang

    2014-04-21

    Zero-refractive-index materials may lead to promising applications in various fields. Here, we design and fabricate a near Zero-Refractive-Index (ZRI) material using a phononic crystal (PC) composed of a square array of densely packed square iron rods in air. The dispersion relation exhibits a nearly flat band across the Brillouin zone at the reduced frequency f  = 0.5443c/a, which is due to Fabry-Perot (FP) resonance. By using a retrieval method, we find that both the effective mass density and the reciprocal of the effective bulk modulus are close to zero at frequencies near the flat band. We also propose an equivalent tube network model to explain the mechanisms of the near ZRI effect. This FP-resonance-induced near ZRI material offers intriguing wave manipulation properties. We demonstrate both numerically and experimentally its ability to shield a scattering obstacle and guide acoustic waves through a bent structure.

  4. Structure, Mechanism, and Application of Vacuum Insulation Panels in Chinese Buildings

    Directory of Open Access Journals (Sweden)

    Changhai Peng

    2016-01-01

    Full Text Available Thermal insulation is one of the most used approaches to reduce energy consumption in buildings. Vacuum insulation panels (VIPs are new thermal insulation materials that have been used in the domestic and overseas market in the last 20 years. Due to the vacuum thermal insulation technology of these new materials, their thermal conductivity can be as low as 0.004 W/(m·K at the center of panels. In addition, VIPs that are composites with inorganic core and an envelope out of commonly three metallized PET layers and a PE sealing layer can provide B class fire resistance (their core materials are not flammable and are classified as A1. Compared with other conventional thermal insulation materials, the thermal insulation and fire resistance performances form the foundation of VIP’s applications in the construction industry. The structure and thermal insulation mechanism of VIP and their application potential and problems in Chinese buildings are described in detail.

  5. Building the Nonuniversity, Tertiary Care Center Hepatobiliary and Pancreatic Surgery Practice: Structural and Financial Considerations.

    Science.gov (United States)

    Baker, Erin H; Siddiqui, Imran; Vrochides, Dionisios; Iannitti, David A; Martinie, John B; Rorabaugh, Lauren; Jeyarajah, D Rohan; Swan, Ryan Z

    2016-12-01

    Early in their careers, many new surgeons lack the background and experience to understand essential components needed to build a surgical practice. Surgical resident education is often devoid of specific instruction on the business of medicine and practice management. In particular, hepatobiliary and pancreatic (HPB) surgeons require many key components to build a successful practice secondary to significant interdisciplinary coordination and a scope of complex surgery, which spans challenging benign and malignant disease processes. In the following, we describe the required clinical and financial components for developing a successful HPB surgery practice in the nonuniversity tertiary care center. We discuss significant financial considerations for understanding community need and hospital investment, contract establishment, billing, and coding. We summarize the structural elements and key personnel necessary for establishing an effectual HPB surgical team. This article provides useful, essential information for a new HPB surgeon looking to establish a surgical practice. It also provides insight for health-care administrators as to the value an HPB surgeon can bring to a hospital or health-care system.

  6. Analysis of soil-structure interaction and floor response spectrum of reactor building for China advanced research reactor

    International Nuclear Information System (INIS)

    Rong Feng; Wang Jiachun; He Shuyan

    2006-01-01

    Analysis of Soil-Structure Interaction (SSI) and calculation of Floor Response Spectrum (FRS) is substantial for anti-seismic design for China Advanced Research Reactor (CARR) project. The article uses direct method to analyze the seismic reaction of the reactor building in considering soil-structure interaction by establishing two-dimensional soil-structure co-acting model for analyzing and inputting of seismic waves from three directions respectively. The seismic response and floor response spectrum of foundation and floors of the building under different cases have been calculated. (authors)

  7. Auxiliary buildings

    International Nuclear Information System (INIS)

    Lakner, I.; Lestyan, E.

    1979-01-01

    The nuclear power station represents a complicated and a particular industrial project. Consequently, the design of the auxiliary buildings serving the power station (offices, kitchen, refreshment room, workshops, depots, water treatment plant building, boiler houses, etc.) requires more attention than usual. This chapter gives a short survey of the auxiliary buildings already completed and discusses the problems of their design, location and structure. (author)

  8. Building Collaborative Structures for Teachers' Autonomy and Self-Efficacy: The Mediating Role of Participative Management and Learning Culture

    Science.gov (United States)

    Lu, Jiafang; Jiang, Xinhui; Yu, Huen; Li, Dongyu

    2015-01-01

    This study focused on the collaborative structure-building behavior of school principals and examined how such behavior affects teacher empowerment. More important, it tested the mediating effects of participative management and learning culture. By collecting nested data from 104 schools in Hong Kong and adopting multilevel structural equation…

  9. New building envelope structures. Energy saving and moisture technology; Uudet vaipparakenteet. Energian saeaestoe ja kosteustekniikka

    Energy Technology Data Exchange (ETDEWEB)

    Kokko, E.; Ojanen, T.; Salonvaara, M. [VTT Building Technology, Espoo (Finland). Building Physics, Building Services and Fire Technology

    1997-12-31

    The publication summarizes the results that deal with reducing heating energy loss through building envelopes, improving hygric (moisture) behavior of structures and utilization solar energy. The objective was to produce new innovative structures and principles of applications for low-energy houses. The applications with the purpose of reducing heating energy consumption are based on conventional mineral wool and cellular plastic insulation materials, low-emissivity foils and coatings that reduce long-wave thermal radiation and building papers with desired properties. Utilization of solar energy was investigated with a solar energy collector system consisting of transparent insulation and glass layers, air circulation with natural convection and thermal mass. Thick light-weight mineral wool insulation layers in the exterior walls are in practice always somewhat non-ideal which increases convection air flows in or through the walls when compared to ideal structures. Increasing the thickness of the insulation layer makes it more non-ideal and thus susceptible to drawbacks of convection flows. Furthermore the internal moisture in the structure is distributed unevenly increasing the risk for mold growth and rotting. The convection effects in thick walls can be eliminated by isolating the insulation layers with air tight but vapor permeable vertical convection barriers. Significant portion of the total heat transfer in light-weight mineral wool insulation is caused by long-wave radiation (Infrared Radiation - IR). A low-emissivity foil attached directly to a surface of a mineral wool insulation has only a small effect on the thermal resistance of the whole insulation layer. Radiation inside thick insulation layers can be reduced significantly only by making use of fibers with low-emissivity surfaces or fibers transparent to IR-radiation and using low-emissivity foils on the sides of the layers. A `real life` structure consisting of a thick light-weight mineral wool

  10. Developing a new library of materials and structural elements for the simulative evaluation of buildings' energy performance

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulos, Agis M.; Oxizidis, Simos; Papathanasiou, Luciano [Laboratory of Heat Transfer and Environmental Engineering, Department of Mechanical Engineering, Aristotle University Thessaloniki, P.O. Box 483, Thessaloniki 54124 (Greece)

    2008-05-15

    Contemporary building energy simulation programs are not only used by researchers but also are common tools in the hands of engineers and architects. Most of them are using databases of materials and structural elements, with characteristics originating from the country or the broader region where the specific program was developed. Thus, often the particularities met in other countries are not considered. Such a database of materials and constructions systematically used in the Greek building sector was developed for use with the simulation program EnergyPlus, which has become quite popular over the last years. In order to determine the applicability of the database, the energy behaviour of a typical multistory, multifamily building was simulated, having the exact materials and structural elements and patterns used in Greece. Furthermore, different thicknesses of insulation were simulated, corresponding to local climatic conditions and, even more important, to different dates of the building's construction. The results are presented and discussed in this paper. (author)

  11. On the effectiveness of smart technologies in the seismic protection of existing buildings Part I: Masonry structures

    International Nuclear Information System (INIS)

    Mandara, A.; Ramundo, F.; Spina, G.

    2008-01-01

    The first part of a study concerning innovative intervention techniques for dissipate a share of the input seismic energy compatible with the preservation of existing buildings, including historical and monumental constructions, is presented in this paper. The case of a typical scheme of a long-bay box-like masonry building fitted with a dissipative floating roof is analyzed. In the examined building a wide simulation analysis has shown the achievement of a very satisfying performance. Furthermore, the effectiveness of the system can be maximized by means of active or semi-active devices implemented in the floating roof and a significant reduction of the seismic impact on the building can be obtained compared with non-controlled or simply passively controlled structure. The results prove the remarkable increase of the energy dissipation capability of the system, as well as the reduction of structural damage, independently of any specific strengthening intervention

  12. Floor Response Spectra of Nuclear Containment Building with Soil-Structure Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Choon Gyo; Ryu, Jeong Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-10-15

    This paper presents a seismic analysis technique for a 3D soil-structure interaction(SSI) system in frequency domain, based on the finite element formulation incorporating frequency-dependent dynamic infinite elements for the far field soil region. Earthquake input motions are regarded as traveling SV-wave which is vertically incident from a far-field soil region. In which, the equivalent earthquake forces in the frequency domain are calculated using the exterior rigid boundary method and the free field response analysis. For the application, floor response spectra analyses for nuclear containment building on a soil medium is carried out, the obtained results are compared with the free field response by other solution.

  13. Soil structure interaction model and variability of parameters in seismic analysis of nuclear island connected building

    International Nuclear Information System (INIS)

    Subramanian, K.V.; Palekar, S.M.; Bavare, M.S.; Mapari, H.A.; Patel, S.C.; Pillai, C.S.

    2005-01-01

    This paper provides salient features of the Soil Structure Interaction analysis of Nuclear Island Connected Building (NICB). The dynamic analysis of NICB is performed on a full 3D model accounting for the probable variation in the stiffness of the founding medium. A range analyses was performed to establish the effect of variability of subgrade parameters on the results of seismic analyses of NICB. This paper presents details of various analyses with respect to the subgrade model, uncertainties in subgrade properties, results of seismic analyses and a study of effect of the variability of parameters on the results of these analyses. The results of this study indicate that the variability of soil parameters beyond a certain value of shear wave velocity does not influence the response and in fact the response marginally diminishes. (authors)

  14. The human factor as a cause of failures in building structures

    Directory of Open Access Journals (Sweden)

    Vondráčková Terezie

    2017-01-01

    Full Text Available Human error can be defined as any unintentional or inadequate decision, taken at any level in the hierarchy of an organization, which is, or was inappropriate in a given situation. Human errors can occur in all human activities across an organization - at a managerial, conceptual or technical level – in connection with mistakes in the construction project itself, mistakes made by the investor, mistakes made by those using the building, mistakes in supplier relations, mistakes in the maintenance of the structure, and others. The factors that can affect the reliability of those people making the decisions that lead to the mistakes include the quality of their education, their experience with stress, or lack thereof, as well as issues such as workload, fatigue, workplace ergonomics, working hours, social climate and private matters.

  15. Characteristics of Soil Structure Interaction for Reactor Building of Kashiwazaki-Kariwa Nuclear Power Plant

    International Nuclear Information System (INIS)

    Gil, Moon Joo; Jung, Rae Young; Hyun, Chang Hun; Kim, Moon Soo; Lim, Nam Hyoung

    2010-01-01

    On 16 July 2007, the Nigataken-chuetsu-oki earthquake registering a moment magnitude of 6.8 occurred at a depth of about 15 km. As a result of this earthquake, noticeable shaking exceeding the design ground motion was measured at the Tokyo Electric Power Company (TEPCO) Kashiwazaki-Kariwa Nuclear Power Station (KKN), the biggest nuclear power plant in the world, located at about 16 km away from the epicenter. This earthquake triggered a fire at an electrical transformer and insignificant damage on some parts of facilities. This event gave an impulse to study on the damage and safety margin of nuclear power plant due to the strong earthquake exceeding design basis. As a part of those efforts, KARISMA (KAshiwazaki-Kariwa Research Initiative for Seismic Margin Assessment) benchmark study was launched by the IAEA in terms of an international collaborative research. The main objectives of this research are to estimate the structural behavior and to evaluate the seismic margin of reactor building considering the effects of Soil-Structure Interaction (SSI). This paper presents verification of structural model developed here and validation of soil foundation characteristics through soil-column analysis. It has also been demonstrated that the spring constants and damping coefficient obtained from impedance analysis represent well the soil foundation characteristics

  16. Structural analysis and design of a nuclear power plant building for aircraft crash effects

    International Nuclear Information System (INIS)

    Degen, P.; Furrer, H.; Jemielewski, J.

    1976-01-01

    The object of this investigation is to assess the effect of a large commercial airplane crashing perpendicularly on to the surface of a spherical reactor building dome. This investigation is related to a project currently in execution. Practical solutions of the postulated case, which vary in the degree of engineering effort used, are shown. Based on safety consideration the various solutions are discussed from the viewpoint of penetration, cracking and collapse modes of failure, where, primarily, the carrying capacity of the structure under an equivalent statical load is considered. The performed investigations include: (a) Calculation of the failure load following the yield line theory; (b) Calculation of the sectional forces using the linear-elastic shell theory and subsequent design by the ultimate strength method; (c) Calculation of the failure load, establishing of the failure mechanism and distribution of sectional forces using the plastic shell theory; (d) Calculation using a three-dimensional FEM program with plastic capabilities; this includes the collapse load, the failure mechanism and the distribution of sectional forces. A discussion of the resultant forces and the configuration of the critical section is given for the various methods used. The evaluation of the carrying capacity of the structure with respect to load is based on energy considerations. It is attempted to compare such results, to evaluate possible simplifications in the used solutions, and to give some recommendations for the practical design and for the development of structural details. (Auth.)

  17. Structural vibration passive control and economic analysis of a high-rise building in Beijing

    Science.gov (United States)

    Chen, Yongqi; Cao, Tiezhu; Ma, Liangzhe; Luo, Chaoying

    2009-12-01

    Performance analysis of the Pangu Plaza under earthquake and wind loads is described in this paper. The plaza is a 39-story steel high-rise building, 191 m high, located in Beijing close to the 2008 Olympic main stadium. It has both fluid viscous dampers (FVDs) and buckling restrained braces or unbonded brace (BRB or UBB) installed. A repeated iteration procedure in its design and analysis was adopted for optimization. Results from the seismic response analysis in the horizontal and vertical directions show that the FVDs are highly effective in reducing the response of both the main structure and the secondary system. A comparative analysis of structural seismic performance and economic impact was conducted using traditional methods, i.e., increased size of steel columns and beams and/or use of an increased number of seismic braces versus using FVD. Both the structural response and economic analysis show that using FVD to absorb seismic energy not only satisfies the Chinese seismic design code for a “rare” earthquake, but is also the most economical way to improve seismic performance both for one-time direct investment and long term maintenance.

  18. SENSITIVITY ANALYSIS OF BUILDING STRUCTURES WITHIN THE SCOPE OF ENERGY, ENVIRONMENT AND INVESTMENT

    Directory of Open Access Journals (Sweden)

    František Kulhánek

    2015-10-01

    Full Text Available The primary objective of this paper is to prove the feasibility of sensitivity analysis with dominant weight method for structure parts of envelope of buildings inclusive of energy; ecological and financial assessments, and determination of different designs for same structural part via multi-criteria assessment with theoretical example designs ancillary. Multi-criteria assessment (MCA of different structural designs or in other word alternatives aims to find the best available alternative. The application of sensitivity analysis technique in this paper bases on dominant weighting method. In this research, to choose the best thermal insulation design in the case of that more than one projection, simultaneously, criteria of total thickness (T; heat transfer coefficient (U through the cross section; global warming potential (GWP; acid produce (AP; primary energy content (PEI non renewable and cost per m2 (C are investigated for all designs via sensitivity analysis. Three different designs for external wall (over soil which are convenient with regard to globally suggested energy features for passive house design are investigated through the mentioned six projections. By creating a given set of scenarios; depending upon the importance of each criterion, sensitivity analysis is distributed. As conclusion, uncertainty in the output of model is attributed to different sources in the model input. In this manner, determination of the best available design is achieved. The original outlook and the outlook afterwards the sensitivity analysis are visualized, that enables easily to choose the optimum design within the scope of verified components.

  19. Evaluation Aspects of Building Structures Reconstructed After a Failure or Catastrophe

    Science.gov (United States)

    Krentowski, Janusz R.; Knyziak, Piotr

    2017-10-01

    The article presents the characteristics of several steel structures, among others modernized industrial dye house, school sports hall, truck repair workshop, that have been rebuilt after a disaster or a catastrophe. The structures were analyzed in detail, and the evaluation and reconstruction processes were described. The emergencies that occurred during exploitation of the buildings were the result of multiple mistakes: incorrectly defined intervals between inspections, errors during periodic inspections, incorrect repair work recommendations. The concepts of reinforcement work implemented by the authors, enabling the long-term future failure-free operation of the objects, were presented. Recommendations for monitoring of the facilities, applied after reinforcement or reconstruction, have been formulated. The methodology for the implementation of specialized investigations, such as geodetic, optical, geological, chemical strength tests, both destructive and non-destructive, has been defined. The need to determine the limit values of deformations, deflections, damage or other faults of structural elements and the entire rebuilt facilities, as well as defining conditions for objects’ withdrawal from operation in subsequent exceptional situations was indicated.

  20. Influence of the Soil-Structure Interaction on the Design of Steel-Braced Building Foundation

    International Nuclear Information System (INIS)

    Azarbakht, Alireza; Ashtiany, Mohsen Ghafory

    2008-01-01

    The modeling and analysis of the superstructure and the foundation for the seismic lateral loads are traditionally done separately. This assumption is an important issue in the design/rehabilitate procedures especially for the short period structures, i.e. steel braced or shear wall systems, which may result to a conservative design. By using more advance procedures, i.e. nonlinear static method, and the incorporation of the soil-structure interaction (SSI), the seismic demand in the lateral resisting system decreases and the design will become more economic. This paper includes an investigation about the influence of the SSI effect on the design of the steel-braced building foundation. The presented example is a three-bay three-storey steel braced frame. Three design methods based on the FEMA 356 guideline and the UBC 97 code are taken in to consideration. The three methods are: (1) linear static analysis based on the UBC 97 code assuming the fixed based condition; (2) linear static analysis based on the FEMA 356 guideline assuming the fixed based condition; and (3) nonlinear static analysis assuming both fixed and flexible based assumptions. The results show that the influence of the SSI on the input demand of the short period building foundations is significant and the foundation design based on the linear static method with the fixed base assumption is so conservative. A simple method is proposed to take the SSI effect in to consideration in the linear static procedure with the fixed base assumption, which is a common method for the engineers. The advantage of this proposed method is the simplicity and the applicability for the engineering purposes

  1. Software package to automate the design and production of translucent building structures made of pvc

    Directory of Open Access Journals (Sweden)

    Petrova Irina Yur’evna

    2016-08-01

    Full Text Available The article describes the features of the design and production of translucent building structures made of PVC. The analysis of the automation systems of this process currently existing on the market is carried out, their advantages and disadvantages are identified. Basing on this analysis, a set of requirements for automation systems for the design and production of translucent building structures made of PVC is formulated; the basic entities are involved in those business processes. The necessary functions for the main application and for dealers’ application are specified. The main application is based on technological platform 1C: Enterprise 8.2. The dealers’ module is .NET application and is developed with the use of Microsoft Visual Studio and Microsoft SQL Server because these software products have client versions free for end users (.NET Framework 4.0 Client Profile and Microsoft SQL Server 2008 Express. The features of the developed software complex implementation are described; the relevant charts are given. The scheme of system deployment and protocols of data exchange between 1C server, 1C client and dealer is presented. Also the functions supported by 1C module and .NET module are described. The article describes the content of class library developed for .NET module. The specification of integration of the two applications in a single software package is given. The features of the GUI organization are described; the corresponding screenshots are given. The possible ways of further development of the described software complex are presented and a conclusion about its competitiveness and expediency of new researches is made.

  2. Characterization of changes in commercial building structure, equipment, and occupants: End-Use Load and Consumer Assessment Program

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, R.G.; Taylor, Z.T.; Miller, N.E.; Pratt, R.G.

    1990-12-01

    Changes in commercial building structure, equipment, and occupants result in changes in building energy use. The frequency and magnitude of those changes have substantial implications for conservation programs and resource planning. For example, changes may shorten the useful lifetime of a conservation measure as well as impact the savings from that measure. This report summarizes the frequency of changes in a commercial building sample that was end-use metered under the End-Use Load and Consumer Assessment Program (ELCAP). The sample includes offices, dry good retails, groceries, restaurants, warehouses, schools, and hotels. Two years of metered data, site visit records, and audit data were examined for evidence of building changes. The observed changes were then classified into 12 categories, which included business type, equipment, remodel, vacancy, and operating schedule. The analysis characterized changes in terms of frequency of types of change; relationship to building vintage and floor area; and variation by building type. The analysis also examined the energy impacts of various changes. The analysis determined that the rate of change in commercial buildings is high--50% of the buildings experienced one type of change during the 2 years for which monitoring data were examined. Equipment changes were found to be most frequent in offices and retail stores. Larger, older office buildings tend to experience a wider variety of changes more frequently than the smaller, newer buildings. Key findings and observations are presented in Section 2. Section 3 provides the underlying motivation and objectives. In Section 4, the methodology used is documented, including the commercial building sample and the data sources used. Included are the definitions of change events and the overall approach taken. Results are analyzed in Section 5, with additional technical details in Appendixes. 2 refs., 46 figs., 22 tabs. (JF)

  3. Isostatic lines’ study to optimize steel space grid envelope structures for tall buildings according to their solicitations

    OpenAIRE

    Señís López, Roger

    2013-01-01

    Based on the first study completed with wind tunnel tests, the aim of this paper is to define a second methodology for the optimization of steel space grid envelope structures for tall buildings according to their isostatic lines according to their solicitations. It is by means of the comparison NatHaz online database and numerical simulation research of wind flow repercussion in buildings, through Computational Fluid Dynamics (CDF), that we can understand and analyse the grid ...

  4. Effects of reinforcement ratio and arrangement on the structural behavior of a nuclear building under aircraft impact

    International Nuclear Information System (INIS)

    Thai, Duc-Kien; Kim, Seung-Eock; Lee, Hyuk-Kee

    2014-01-01

    Highlights: • Numerical analysis of RC nuclear building model under aircraft impact was conducted. • The analysis result shows similar behavior as compared to the Riera function. • The effects of reinforcement ratio and arrangement were enumerated. • The appropriate number of layer of longitudinal rebar was recommended. - Abstract: This study presents the effectiveness of the rebar ratio and the arrangement of reinforced concrete (RC) structures on the structural behavior of nuclear buildings under aircraft impact using a finite element (FE) approach. A simplified model of a fictitious nuclear building using RC structures was fully modeled. The aircraft model of a Boeing 767-400 was used for impact simulation and was developed and verified with a conventional impact force–time history curve. The IRIS Punching test was used to validate the damage prediction capabilities of the RC wall under impact loading. With regard to the different rebar ratios and rebar arrangements of a nuclear RC building, the structural behavior of a building under aircraft impact was investigated. The structural behavior investigated included plastic deformation, displacement, energy dissipation, perforation/penetration depth and scabbing area. The results showed that the rebar ratio has a significant effect on withstanding aircraft impact and reducing local damage. With four layers of rebar, the RC wall absorbed and dissipated the impact energy more than once with only two layers of rebar for the same rebar ratio

  5. Evaluation of Seismic Response Trends from Long-Term Monitoring of Two Instrumented RC Buildings Including Soil-Structure Interaction

    Directory of Open Access Journals (Sweden)

    Faheem Butt

    2012-01-01

    Full Text Available This paper presents analyses of the seismic responses of two reinforced concrete buildings monitored for a period of more than two years. One of the structures was a three-storey reinforced concrete (RC frame building with a shear core, while the other was a three-storey RC frame building without a core. Both buildings are part of the same large complex but are seismically separated from the rest of it. Statistical analysis of the relationships between maximum free field accelerations and responses at different points on the buildings was conducted and demonstrated strong correlation between those. System identification studies using recorded accelerations were undertaken and revealed that natural frequencies and damping ratios of the building structures vary during different earthquake excitations. This variation was statistically examined and relationships between identified natural frequencies and damping ratios, and the peak response acceleration at the roof level were developed. A general trend of decreasing modal frequencies and increasing damping ratios was observed with increased level of shaking and response. Moreover, the influence of soil structure interaction (SSI on the modal characteristics was evaluated. SSI effects decreased the modal frequencies and increased some of the damping ratios.

  6. Hiding the interior region of core-shell nanoparticles with quantum invisible cloaks

    Science.gov (United States)

    Lee, Jeng Yi; Lee, Ray-Kuang

    2014-04-01

    Based on the scattering cancellation, we provide a method not only making a nanoparticle nearly invisible, but also hiding its interior region from the outside probing matter wave. By applying the interplay among the nodal points of partial waves along with the concept of streamline in fluid dynamics for probability flux, a quantum invisible cloak to the electron transport in a host semiconductor is demonstrated by simultaneously guiding the probability flux outside a hidden region and keeping the total scattering cross section negligible. As the probability flux vanishes in the interior region, one can embed any materials inside a multiple core-shell nanoparticle without affecting physical observables from the outside. Our results reveal the possibility to design a protection shield layer for fragile interior parts from the impact of transport electrons.

  7. Task-Management Method Using R-Tree Spatial Cloaking for Large-Scale Crowdsourcing

    Directory of Open Access Journals (Sweden)

    Yan Li

    2017-12-01

    Full Text Available With the development of sensor technology and the popularization of the data-driven service paradigm, spatial crowdsourcing systems have become an important way of collecting map-based location data. However, large-scale task management and location privacy are important factors for participants in spatial crowdsourcing. In this paper, we propose the use of an R-tree spatial cloaking-based task-assignment method for large-scale spatial crowdsourcing. We use an estimated R-tree based on the requested crowdsourcing tasks to reduce the crowdsourcing server-side inserting cost and enable the scalability. By using Minimum Bounding Rectangle (MBR-based spatial anonymous data without exact position data, this method preserves the location privacy of participants in a simple way. In our experiment, we showed that our proposed method is faster than the current method, and is very efficient when the scale is increased.

  8. Partial Prestress Concrete Beams Reinforced Concrete Column Joint Earthquake Resistant On Frame Structure Building

    Science.gov (United States)

    Astawa, M. D.; Kartini, W.; Lie, F. X. E.

    2018-01-01

    Floor Building that requires a large space such as for the meeting room, so it must remove the column in the middle of the room, then the span beam above the room will be long. If the beam of structural element with a span length reaches 15.00 m, then it is less effective and efficient using a regular Reinforced Concrete Beam because it requires a large section dimension, and will reduce the beauty of the view in terms of aesthetics of Architecture. In order to meet these criteria, in this design will use partial prestressing method with 400/600 mm section dimension, assuming the partial Prestressed Beam structure is still able to resist the lateral force of the earthquake. The design of the reinforcement has taken into account to resist the moment due to the gravitational load and lateral forces. The earthquake occurring on the frame structure of the building. In accordance with the provisions, the flexural moment capacity of the tendon is permitted only by 25% of the total bending moment on support of the beam, while the 75% will be charged to the reinforcing steel. Based on the analysis result, bring ini 1 (one) tendon contains 6 strand with diameter 15,2 mm. On the beam pedestal, requires 5D25 tensile reinforcement and 3D25 for the compression reinforcement, for shear reinforcement on the pedestal using Ø10-100 mm. Dimensional column section are 600/600 mm with longitudinal main reinforcement of 12D25, and transverse reinforcement Ø10-150. At the core of the beam-column joint, use the transversal reinforcement Ø10-100 mm. The moment of Column versus Beam Moment ∑Me > 1.2 Mg, with a value of 906.99 kNm > 832.25 kNm, qualify for ductility and Strong Columns-weak beam. Capacity of contribution bending moment of Strand Tendon’s is 23.95% from the total bending moment capacity of the beam, meaning in accordance with the provisions. Thus, the stability and ductility structure of Beam-Column joint is satisfy the requirements of SNI 2847: 2013 and ACI 318-11.

  9. Building Knowledge Structures by Testing Helps Children With Mathematical Learning Difficulty.

    Science.gov (United States)

    Zhang, Yiyun; Zhou, Xinlin

    2016-01-01

    Mathematical learning difficulty (MLD) is prevalent in the development of mathematical abilities. Previous interventions for children with MLD have focused on number sense or basic mathematical skills. This study investigated whether mathematical performance of fifth grade children with MLD could be improved by developing knowledge structures by testing using a web-based curriculum learning system. A total of 142 children with MLD were recruited; half of the children were in the experimental group (using the system), and the other half were in the control group (not using the system). The children were encouraged to use the web-based learning system at home for at least a 15-min session, at least once a week, for one and a half months. The mean accumulated time of testing on the system for children in the experimental group was 56.2 min. Children in the experimental group had significantly higher scores on their final mathematical examination compared to the control group. The results suggest that web-based curriculum learning through testing that promotes the building of knowledge structures for a mathematical course was helpful for children with MLD. © Hammill Institute on Disabilities 2014.

  10. Building Structure Housing: Case Study of Community Housing in Kendari City

    Science.gov (United States)

    Umar, M. Z.; Faslih, A.; Arsyad, M.; Sjamsu, A. S.; Kadir, I.

    2017-11-01

    Housing development has been pioneered through a simple home construction program to reduce the production cost. Simple housing program was developed in Kendari City. The purpose of this study is to show the principles of reducing the cost production for the type 36 homes, in Kendari City. The selected architectural objects are the lower, middle and the upper structure of type 36 house. The data collection was done by observation and in-depth discussion with construction workers. The analysis technique used in this research was a descriptive narrative analysis technique in the form of tabulation data. This study concluded that there are several principles of price reduction in the structure of public housing buildings. Quick principles exist in constructing techniques such as using cigarette packs as a foundation pad, mortar usage for rapid wall standing, and the spacing of mortars could be done manually by using two fingers on a human hand. Economic principles could be used for material matters, such as eliminating the use of gravel for concrete, the use of sand material to contain the soil, the foundation does not use sand and empty stone, and the shape of the ring beam was made using triangle reinforcement.

  11. Building 3D structures of vanadium pentoxide nanosheets and application as electrodes in supercapacitors.

    Science.gov (United States)

    Zhu, Jixin; Cao, Liujun; Wu, Yingsi; Gong, Yongji; Liu, Zheng; Hoster, Harry E; Zhang, Yunhuai; Zhang, Shengtao; Yang, Shubin; Yan, Qingyu; Ajayan, Pulickel M; Vajtai, Robert

    2013-01-01

    Various two-dimensional (2D) materials have recently attracted great attention owing to their unique properties and wide application potential in electronics, catalysis, energy storage, and conversion. However, large-scale production of ultrathin sheets and functional nanosheets remains a scientific and engineering challenge. Here we demonstrate an efficient approach for large-scale production of V2O5 nanosheets having a thickness of 4 nm and utilization as building blocks for constructing 3D architectures via a freeze-drying process. The resulting highly flexible V2O5 structures possess a surface area of 133 m(2) g(-1), ultrathin walls, and multilevel pores. Such unique features are favorable for providing easy access of the electrolyte to the structure when they are used as a supercapacitor electrode, and they also provide a large electroactive surface that advantageous in energy storage applications. As a consequence, a high specific capacitance of 451 F g(-1) is achieved in a neutral aqueous Na2SO4 electrolyte as the 3D architectures are utilized for energy storage. Remarkably, the capacitance retention after 4000 cycles is more than 90%, and the energy density is up to 107 W·h·kg(-1) at a high power density of 9.4 kW kg(-1).

  12. Use of shock block transmitters in the structural rehabilitation of historical buildings in Calabria and Sicily

    International Nuclear Information System (INIS)

    Bianco, Alessia; Candela, Michele; Fonti, Roberta

    2008-01-01

    Many old and historical masonry buildings, located in the Calabrian and Sicilian areas near the strait of Messina, are affected by typical pattern of cracks, which are not produced by previous earthquakes. These cracks in the masonry walls are characterized by a quasi-vertical trend with constant width. The careful examination of the crack distribution allows to clearly identify the diagnosis: the damage is caused by the sinking due to a horizontal movement of translation of the ground, which is an evident effect of creep phenomena in the soil, so-called 'solifluxion'. This paper, after showing this geological pathology, proposes an innovative strategy of intervention, which consists of the use of 'oleo-dynamic' devices, so-called shock block transmitters, providing different degrees of restraint, according to the loading conditions. In addition, in case of earthquake, an important part of the in-put seismic energy can be dissipated. The strategy of application of this system to the building consists of the subdivision of each masonry wall in two different parts, which are physically separated by the cracks. Each wall portion must be consolidated separately and the different parts of walls behave as statically independent each other, so that they can move independently during the serviceability conditions. The connection among the walls composing the whole structural organism is given by metal tie-rods equipped with 'oleo dynamic' devices, which allows, in a given range, the horizontal sliding in case of slow movement due to the phenomenon of 'solifluxion'. Contrary, in case of dynamic and fast movements, such as the ones produced by an earthquake, each 'oleo dynamic' device provides a fully restraint effect and, as a consequence, the tie-rods behave in the classical way

  13. Chinese wood frame buildings and the changing dimensions of their structural components in different time periods

    Directory of Open Access Journals (Sweden)

    Nujaba Binte Kabir

    2012-06-01

    Full Text Available The Features of the Chinese wood frame buildings are same in character from dynasty to dynasty. The study concentrates on 9 Chinese wood frame buildings from Tang to Yuan dynasty and tries to relate these buildings with the text described in a building manual book published in Song dynasty Yingzao fashi. The features of some buildings match with the text described in the book some do not. But on the other hand Liang Sicheng, scholar of Chinese architecture in his book claimed that Chinese wood frame architecture has a unique system of characteristics (Liang, 1984. The system of wood frame Chinese architecture did not change but the proportion of the features has changed in different dynasty. The aim of the paper is to compare the features of the buildings those have been studied according to Yingzao fashi with Liang's observation on the change of building style in different periods.

  14. ENERGY DEMANDS OF THE EXISTING COLLECTIVE BUILDINGS WITH BEARING STRUCTURE OF LARGE PRECAST CONCRETE PANELS FROM TIMISOARA

    Directory of Open Access Journals (Sweden)

    Pescari S.

    2015-05-01

    Full Text Available One of the targets of EU Directives on the energy performance of buildings is to reduce the energy consumption of the existing buildings by finding efficient solutions for thermal rehabilitation. In order to find the adequate solutions, the first step is to establish the current state of the buildings and to determine their actual energy consumption. The current paper aims to present the energy demands of the existing buildings with bearing structure of large precast concrete panels in the city of Timisoara. Timisoara is one of the most important cities in the west side of Romania, being on the third place in terms of size and economic development. The Census of Population and Housing of 2011 states that Timisoara has about 127841 private dwellings and 60 percent of them are collective buildings. Energy demand values of the existing buildings with bearing structure of large precast concrete panels in Timisoara, in their current condition, are higher than the accepted values provided in the Romanian normative, C107. The difference between these two values can reach up to 300 percent.

  15. Post-industrial Objects and Buildings in the Structure of the Contemporary City

    Science.gov (United States)

    Klopotowski, Maciej; Zagroba, Marek

    2017-12-01

    In the second half of the 19th century, provincial Bialystok became the largest industrial city in the eastern territories of the former Republic of Poland. The cause of this economic growth was the development of the railway network and changing customs policy in the Russian Empire. Over a dozen or so years, several dozens of textile factories and numerous craft workshops were established in the city. The industrial prosperity of the city development was interrupted by the First and Second World War. The second half of the twentieth century also brought political and economic changes. They resulted from the nationalization of industry and the introduction of a socialist economy. In the following decades, heavy and light industries developed in the city. Metallurgical plants and factories of houses, furniture, carpets, packaging, electronics, glassworks and food processing were established. On the outskirts of the city appeared industrial districts, which except the factories concentrated also storage facilities. Economic changes that took place in Poland after 1989 caused another change in the area of Białystok industry. Many state-owned factories went bankrupt and the remaining facilities and areas had to change their intended use. The conducted research compares the methods of dealing with the currently unnecessary structure. This has taken into account its location value in the city’s structure and its cultural characteristics. Analyses allowed to indicate new use of post-industrial facilities. There were selected post-industrial buildings that currently serve residential, office, educational and commercial purposes or house cultural institutions. There are also indicated facilities that have not found their new destination and have been demolished or are not currently in use. In conclusion, the research found that the city’s post-industrial legacy is equal to its heritage - it builds the identity of the place and it is also the difficult urban problem of

  16. Structural response of nuclear containment shield buildings with unanticipated construction openings

    Science.gov (United States)

    Mac Namara, Sinead Caitriona

    As Nuclear Power Plants age many require steam generator replacement. There is a nickel alloy in the steam generator tubes that is susceptible to stress cracking and although these cracks can be sealed the generator becomes uneconomical without 10%-15% of the tubes. The steam generator in a typical nuclear power plant is housed in the containment structure next to the reactor. The equipment hatch is not big enough to facilitate steam generator replacement, thus construction openings in the dome of the containment structure are required. To date the structural consequences of construction openings in the dome have not been examined. This thesis examines the effects of such openings. The prototype concrete dome is made up of a 2 ft thick dome atop 3 ft thick and 170 ft high cylindrical walls (radius 65.5 ft) with a tension ring 15 ft high and 8 ft thick in between. The dome of the building is cast in two layers; a lower 9 inch layer that serves as the formwork for an upper 15 inch layer. The weight of the dome is carried in axial compression along the hoops and meridians of the dome. The first finite element model uses shell elements and considers two limiting load cases; where the two layers act as one, and where the lower layer carries the weight of both. The openings interrupt the hoops and meridians and the weight of the dome must be redistributed around the openings. Without openings, the stresses due to dead load in the structure are very low when compared to the material strength. The impact of the openings is increased compression stresses near the opening. The maximum stresses are approximately four times larger than in the original structure. These results are confirmed by the second model which is made from layers of solid elements. This model shows a significant difference between the compression on the top surface of the dome, in the affected areas, and that on the bottom surface, leading to shear stresses. These shear stresses are largest around the

  17. VERTICAL PROJECTION EFFICIENCY OF PIVOT POINTS USING ELECTRONIC TACHEOMETER DURING CONSTRUCTION OF BUILDINGS AND STRUCTURES

    Directory of Open Access Journals (Sweden)

    M. S. Nesterenok

    2014-01-01

    Full Text Available The paper shows that functional limitation of zenith devices and introduction of modern high-accuracy electronic tacheometers should lead to substitution of the mentioned devices for tacheometers in geodesic works concerning vertical projection of pivot points of the constructed buildings and structures. However the electronic tacheometer has not been considered in the function of a zenith device in ТКП 45-1.03-26-2006.Special experiemnts and practical works executed by UE “Geokart” has proved that in accordance with its design the electronic tacheometer equipped with a compensator for small inclinations and zenith prism attachment for ocular can be applied as a vertical projection device while setting sighting line of a telescope in a fixed vertical position. Corresponding experiments have been carried out for multi-storied building of business centre located in the M. Tank Street in Minsk in order to obtain comparative characteristics of vertical projection accuracy with the help of tacheometer TOPCON GPT 7501 and zenith device PZL-100. An initial point of the staked grid has been situated at the elevation ±0,0 м, standard graph elevation has been equal to +49,5 м (concrete slab of the 14th floor, projection height referred to the device has been equal to Н = 47,8 м. Both devices have been set on the same stand using a purpose made adaptive device in order to exclude centering errors. Deviation in position of final projection points on the standard graph which were obtained with the help of two devices has been equal to 1.2 mm, that testifies practical equal accuracy of the zenith device and tacheometer for vertical projection function.Additional advantage of the electronic tacheometer in comparison with special vertical projection devi ces lies in the fact that in the case of a certain misalignment of geodesic openings in intermediate floors ta- cheometer deviating from the vertical makes it possible to carry out initial point

  18. Seismic soil structure interaction analysis for asymmetrical buildings supported on piled raft for the 2015 Nepal earthquake

    Science.gov (United States)

    Badry, Pallavi; Satyam, Neelima

    2017-01-01

    Seismic damage surveys and analyses conducted on modes of failure of structures during past earthquakes observed that the asymmetrical buildings show the most vulnerable effect throughout the course of failures (Wegner et al., 2009). Thus, all asymmetrical buildings significantly fails during the shaking events and it is really needed to focus on the accurate analysis of the building, including all possible accuracy in the analysis. Apart from superstructure geometry, the soil behavior during earthquake shaking plays a pivotal role in the building collapse (Chopra, 2012). Fixed base analysis where the soil is considered to be infinitely rigid cannot simulate the actual scenario of wave propagation during earthquakes and wave transfer mechanism in the superstructure (Wolf, 1985). This can be well explained in the soil structure interaction analysis, where the ground movement and structural movement can be considered with the equal rigor. In the present study the object oriented program has been developed in C++ to model the SSI system using the finite element methodology. In this attempt the seismic soil structure interaction analysis has been carried out for T, L and C types piled raft supported buildings in the recent 25th April 2015 Nepal earthquake (M = 7.8). The soil properties have been considered with the appropriate soil data from the Katmandu valley region. The effect of asymmetry of the building on the responses of the superstructure is compared with the author's research work. It has been studied/observed that the shape or geometry of the superstructure governs the response of the superstructure subjected to the same earthquake load.

  19. Influence of Steel Fibers on the Structural Performance of a Prestressed Concrete Containment Building

    International Nuclear Information System (INIS)

    Choun, Youngsun; Hahm, Daegi; Park, Junhee

    2013-01-01

    A large number of previous experimental investigations indicate that the use of steel fibers in conventional reinforced concrete (RC) can enhance the structural and functional performance of prestressed concrete containment buildings (PCCBs) in nuclear power plants. A prevention of through-wall cracks and an increase of the post-cracking ductility will improve the ultimate internal pressure capacity, and a high shear resistance under cyclic loadings will increase the seismic resisting capacity. In this study, the effects of steel fiber reinforced concrete (SFRC) on the ultimate pressure and seismic capacities of a PCCB are investigated. The effects of steel fibers on the ultimate pressure and shear resisting capacities of a PCCB are investigated. It is revealed that both of the ultimate pressure capacity and the shear resisting capacity of a PCCB can be greatly enhanced by introducing steel fibers in a conventional RC. Estimation results indicate that the ultimate pressure capacity and maximum lateral displacement of a PCCB can be improved by 16% and 64%, respectively, if a conventional RC contains hooked steel fibers in a volume fraction of 1.0%

  20. Bacterial community structures in air conditioners installed in Japanese residential buildings.

    Science.gov (United States)

    Hatayama, Kouta; Oikawa, Yurika; Ito, Hiroyuki

    2018-01-01

    The bacterial community structures in four Japanese split-type air conditioners were analyzed using a next-generation sequencer. A variety of bacteria were detected in the air filter of an air conditioner installed on the first floor. In the evaporator of this air conditioner, bacteria belonging to the genus Methylobacterium, or the family of Sphingomonadaceae, were predominantly detected. On the other hand, the majority of bacteria detected in the air filters and evaporators of air conditioners installed on the fifth and twelfth floors belonged to the family Enterobacteriaceae. The source of bacteria belonging to the family Enterobacteriaceae may have been aerosols generated by toilet flushing in the buildings. Our results suggested the possibility that the bacterial contamination in the air conditioners was affected by the floor level on which they were installed. The air conditioner installed on the lower floor, near the ground, may have been contaminated by a variety of outdoor bacteria, whereas the air conditioners installed on floors more distant from the ground may have been less contaminated by outdoor bacteria. However, these suppositions may apply only to the specific split-type air conditioners that we analyzed, because our sample size was small.