Sedimentation of Rigid Cylindrical Particles with Mechanical Contacts
Institute of Scientific and Technical Information of China (English)
LIN Jian-Zhong; WANG Ye-Long; James A. Olsen
2005-01-01
@@ A collision model of two cylindrical particles is put forward. Based on the model the sedimentation of rigid cylindrical particles with mechanical contacts is simulated numerically by using the lattice Boltzmann method.
Institute of Scientific and Technical Information of China (English)
SONG Tian-shu; SUN Li-li; YU Zhen-dong
2005-01-01
Scattering and dynamic stress concentrations of time harmonic SH-wave in an infinite elastic piezoelectric medium with a movable rigid cylindrical inclusion are studied in this paper with the help of complex variable and wave function expansion method. The relations that a movable rigid cylindrical inclusion depends on intensity of incident wave and electric field are revealed. The expressions of dynamic stress at the edge of the inclusion are obtained. Numerical calculations are made with different wave numbers and different piezoelectric characteristic parameters. The calculating results show that dynamic stress concentrations at the edge of the inclusion have linear dependence on the incident electric field. And dynamic analyses are very important for an infinite piezoelectric medium with a movable rigid cylindrical inclusion at larger piezoelectric characteristic parameters.
Renovating a Fusee Ceramique Barrel Vault
Kamerling, M.W.
2015-01-01
This paper describes a proposal to renovate a Fusee Ceramique Barrel Vault with steel diagonals In 1956 two workshops, varying in height and span, were built in Wormerveer, The Netherlands. Both workshops were roofed with a concrete barrel vault with a thickness of 110 mm. The cylindrical vaults w
Lubrication analysis of interacting rigid cylindrical particles in confined shear flow
Energy Technology Data Exchange (ETDEWEB)
Cardinaels, R., E-mail: R.M.Cardinaels@tue.nl [Polymer Technology, Department of Mechanical Engineering, TU Eindhoven, Den Dolech 2, 5612 AZ, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200f, P.O. Box 2424, BE3001 Leuven (Belgium); Department of Mechanical and Aerospace Engineering, Princeton University, D328 Engineering Quadrangle, Princeton, New Jersey 08544 (United States); Stone, H. A., E-mail: H.A.Stone@Princeton.edu [Department of Mechanical and Aerospace Engineering, Princeton University, D328 Engineering Quadrangle, Princeton, New Jersey 08544 (United States)
2015-07-15
Lubrication analysis is used to determine analytical expressions for the elements of the resistance matrix describing the interaction of two rigid cylindrical particles in two-dimensional shear flow in a symmetrically confined channel geometry. The developed model is valid for non-Brownian particles in a low-Reynolds-number flow between two sliding plates with thin gaps between the two particles and also between the particles and the walls. Using this analytical model, a comprehensive overview of the dynamics of interacting cylindrical particles in shear flow is presented. With only hydrodynamic interactions, rigid particles undergo a reversible interaction with no cross-streamline migration, irrespective of the confinement value. However, the interaction time of the particle pair substantially increases with confinement, and at the same time, the minimum distance between the particle surfaces during the interaction substantially decreases with confinement. By combining our purely hydrodynamic model with a simple on/off non-hydrodynamic attractive particle interaction force, the effects of confinement on particle aggregation are qualitatively mapped out in an aggregation diagram. The latter shows that the range of initial relative particle positions for which aggregation occurs is increased substantially due to geometrical confinement. The interacting particle pair exhibits tangential and normal lubrication forces on the sliding plates, which will contribute to the rheology of confined suspensions in shear flow. Due to the combined effects of the confining walls and the particle interaction, the particle velocities and resulting forces both tangential and perpendicular to the walls exhibit a non-monotonic evolution as a function of the orientation angle of the particle pair. However, by incorporating appropriate scalings of the forces, velocities, and doublet orientation angle with the minimum free fraction of the gap height and the plate speed, master curves for
Bulging Modes of Circular Bottom Plates in Rigid Cylindrical Containers Filled with a Liquid
Directory of Open Access Journals (Sweden)
Marco Amabili
1997-01-01
Full Text Available In this article the free vibrations of the bottom plate of an otherwise rigid circular cylindrical tank filled with liquid are studied, considering only the bulging modes (when the amplitude of the plate displacement is predominant with respect to that of the free surface. The tank axis is vertical, thus the free liquid surface is orthogonal to the tank axis. The liquid is assumed to be inviscid, and the contribution of the free surface waves to the dynamic pressure on the free liquid surface is neglected. Wet and dry mode shapes of the plate are assumed to be the same, so that the natural frequencies are obtained by using the nondimensionalized added virtual mass incremental (NA VMI factors and the modal properties of dry plates. This simplifies computations compared to other existing theoretical approaches. NAVMI factors express the nondimensionalized ratio between the reference kinetic energy of the liquid and that of the plate and have the advantage that, due to their nondimensional form, they can be computed once and for all. Numerical results for simply supported and clamped bottom plates, as well as for supported plates with an elastic moment edge constraint are given. For more accurate results, and to exceed the limits of the assumed modes approach, the Rayleigh-Ritz method is applied and results are compared to those obtained by using the NAVMI factors and other existing methods in the literature.
Energy Technology Data Exchange (ETDEWEB)
Mitri, F. G., E-mail: F.G.Mitri@ieee.org [Chevron, Area 52 Technology, ETC, Santa Fe, New Mexico 87508 (United States)
2015-11-14
Using the partial-wave series expansion method in cylindrical coordinates, a formal analytical solution for the acoustical scattering of a 2D cylindrical quasi-Gaussian beam with an arbitrary angle of incidence θ{sub i}, focused on a rigid elliptical cylinder in a non-viscous fluid, is developed. The cylindrical focused beam expression is an exact solution of the Helmholtz equation. The scattering coefficients for the elliptical cylinder are determined by forcing the expression of the total (incident + scattered) field to satisfy the Neumann boundary condition for a rigid immovable surface, and performing the product of matrices involving an inversion procedure. Computations for the matrices elements require a single numerical integration procedure for each partial-wave mode. Numerical results are performed with particular emphasis on the focusing properties of the incident beam and its angle of incidence with respect to the major axis a of the ellipse as well as the aspect ratio a/b where b is the minor axis (assuming a > b). The method is validated and verified against previous results obtained via the T-matrix for plane waves. The present analysis is the first to consider an acoustical beam on an elliptic cylinder of variable cross-section as opposed to plane waves of infinite extent. Other 2D non-spherical and Chebyshev surfaces are mentioned that may be examined throughout this analytical formalism assuming a small deformation parameter ε.
Mitri, F. G.
2017-08-01
The multiple scattering effects occurring between two scatterers are described based upon the multipole expansion formalism as well as the addition theorem of cylindrical wave functions. An original approach is presented in which an effective incident acoustic field on a particular object, which includes both the primary and re-scattered waves from the other particle is determined first, and then used with the scattered field to derive closed-form analytical expressions for the inherent (i.e. intrinsic) cross-sections based on the far-field scattering. This method does not introduce any approximation in the calculation of the intrinsic cross-sections since the procedure is reduced to the one-body problem. The mathematical expressions for the intrinsic cross-sections are formulated in partial-wave series expansions (PWSEs) in cylindrical coordinates involving the angle of incidence, the addition theorem for the cylindrical wave functions, and the expansion coefficients of the scatterers. Numerical examples illustrate the analysis for two rigid circular cylindrical cross-sections with different radii immersed in a non-viscous fluid. Computations for the dimensionless extrinsic and intrinsic extinction cross-section factors are evaluated with particular emphasis on varying the angle of incidence, the interparticle distance, as well as the sizes of the particles. A symmetric behavior is observed for the dimensionless extrinsic extinction cross-section, while asymmetry arises for the intrinsic extinction cross-section of each particle with respect to the angle of incidence. The present analysis provides a complete analytical and computational method for the prediction of the intrinsic (local) scattering, absorption and extinction cross-sections in the multiple acoustic scatterings of plane progressive waves of arbitrary incidence by a pair of scatterers. The results and computational analyses can be used as a priori information for future applications to guide the
Honeycutt, Rebecca L.; Johnson, Steven J.
1993-04-01
The sound scattering due to an ambient noise field, approximated by a squared cosine function, is considered for infinite rigid and elastic cylinders and rigid spheres. For the cylinders, it is assumed that the acoustic wave front is parallel to the axis of the cylinder (informally incident). For this assumption, a closed form expression for the scattered sound field-to-incident ambient noise field (signal-to-noise) ratio is obtained not only for the cosine squared directivity, but for any arbitrary directivity which can be expressed in terms of a Fourier series. For the sphere, it is assumed that the noise is circumferentially symmetric which leads to a closed form expression for the signal-to-noise ratio due to a cosine squared directivity.
Indian Academy of Sciences (India)
N CHOUDHARY; S N BORA
2017-05-01
Sloshing in any type of container may invite instability to it. If some part of the free liquid surface in the annular region of a specially designed circular cylindrical container is covered with an annular baffle, the natural frequencies and the response of the liquid in the container undergo a drastic change. A partly covered free surface shifts the natural frequency above and away from the control frequency of the vehicle, in which the liquid-filled container is placed, which results in the reduction of sloshing mass participating in the dynamicmotion of the system. The fundamental natural frequency of an inviscid and incompressible liquid is determined for increasing width of the baffle that is attached to the outer tank wall on the free surface. It is observed that by increasing the width of the baffle, natural frequencies can be significantly increased. Investigations are also carried out for different values of Bond number, which depicts different states of surface tension, and for varyingvalues of the part of the radius in the fluid region. It is also observed that by increasing the fluid height inside the container, the natural frequencies can be increased, which results in reduction of sloshing.
Directory of Open Access Journals (Sweden)
Azubuike Uzoma
2009-01-01
Vault prolapse repair rely on either the use of patient's tissue or synthetic materials and can be carried out abdominally or vaginally. Sacrospinous fixation and abdominal sacrocolpopexy are the commonly performed procedures, with literature in favour of abdominal sacrocolpopexy over sacrospinous fixation due to its reported higher success rate of about 90%. Other less commonly performed procedures include uterosacral ligament suspension and illiococcygeal fixation, both of which are equally effective, with the former having a high risk of ureteric injury. Colpoclesis will play a greater role in the future as the aging population increases. Mesh procedures are gaining in popularity, and preliminary data from vaginal mesh procedures is encouraging. Laparoscopic techniques require a high level of skill and experience. There are many controversies on the mechanism of prolapse and management techniques, which we have tried to address in this article. Conclusion. As the aging population increases, the incidence of prolapse will also rise, older techniques using native tissue will continue, while new techniques using the mesh needs to be studied further. The later may well be the way forward in future.
Radiological dose assessment for vault storage concepts
Energy Technology Data Exchange (ETDEWEB)
Richard, R.F.
1997-02-25
This radiological dose assessment presents neutron and photon dose rates in support of project W-460. Dose rates are provided for a single 3013 container, the ``infloor`` storage vault concept, and the ``cubicle`` storage vault concept.
Apical vault repair, the cornerstone or pelvic vault reconstruction.
Ross, J W
1997-01-01
Pelvic organ prolapse remains a difficult problem for pelvic reconstructive surgery. Before new surgical procedures can be developed a good understanding of pelvic anatomy is necessary. It is widely held that the etiology of pelvic organ prolapse is secondary to stretch neuropathy following childbirth and chronic cough or constipation. Several transvaginal and transabdominal procedures have been developed over the years. With the increasing use of laparoscopy, a new variation on existing culdeplasty techniques has been developed. Following anatomical principles, the apical vault repair reestablishes the pericervical ring at the vaginal apex. The incorporation of pubocervical fascia, uterosacral-cardinal ligament and the rectovaginal fascia provides a strong anchor for the vaginal apex. In addition, the repair should help prevent future transverse cystocele, rectocele, enterocele and apical vault prolapse. Early outcome studies suggest that the apical vault repair should be used routinely with laparoscopic urethropexy, laparoscopic hysterectomy and the repair of pelvic organ prolapse. Good apical vault support is considered the cornerstone of pelvic reconstruction.
Desalination of painted brick vaults
DEFF Research Database (Denmark)
Larsen, Poul Klenz
The subject of the thesis is salt and moisture movement that causes damage to wall paintings on church vaults. The deterioration was studied in the churches of Fanefjord, Kirkerup and Brarup. A desalination method was tested om location. The salt and moisture transfer was examined in detail...
Desalination of painted brick vaults
DEFF Research Database (Denmark)
Larsen, Poul Klenz
The subject of the thesis is salt and moisture movement that causes damage to wall paintings on church vaults. The deterioration was studied in the churches of Fanefjord, Kirkerup and Brarup. A desalination method was tested om location. The salt and moisture transfer was examined in detail...
PRTR ion exchange vault water removal
Energy Technology Data Exchange (ETDEWEB)
Ham, J.E.
1995-11-01
This report documents the removal of radiologically contaminated water from the Plutonium Recycle Test Reactor (PRTR) ion exchange vault. Approximately 57,000 liters (15,000 gallons) of water had accumulated in the vault due to the absence of a rain cover. The water was removed and the vault inspected for signs of leakage. No evidence of leakage was found. The removal and disposal of the radiologically contaminated water decreased the risk of environmental contamination.
Institute of Scientific and Technical Information of China (English)
宋殿义; 刘飞; 蒋志刚
2013-01-01
考虑金属厚靶侧面自由边界的影响,研究了刚性尖头弹侵彻有限平面尺寸金属厚靶问题.基于有限柱形空腔膨胀理论和线性硬化材料模型,得到了空腔壁径向压力的解析式,建立了刚性尖头弹侵彻有限直径圆柱形金属厚靶工程模型.与试验和数值模拟比较表明,该文工程模型计算精度很好.基于所建立的工程模型,研究了靶板半径对侵彻深度和侵彻阻力的影响,结果表明:当靶板与弹丸半径比值小于20时,靶板半径对侵彻阻力和侵彻深度有显著影响,不能按无限尺寸靶板计算；当靶板与弹丸半径比值大于20时,靶板半径对侵彻阻力和侵彻深度影响较小,可近似按无限尺寸靶计算.%The penetration of thick mental targets with finite planner dimensions by a rigid sharp-nose was investigated in the consideration of the lateral free boundary of the target. Based on the Finite Cylindrical Cavity Expansion (FCCE) theory and the linear strain-hardening material model, analytical solutions of radial pressure on the cavity wall were obtained, and an engineering model for rigid sharp-nosed projectile penetration into cylindrical thick metal targets was presented. The penetration depths from the present model are in a good agreement with those from the published ballistic experiments and numerical simulation. Based on the model, the influence of a target radius on penetration depth and penetration resistance was studied. The results show that the penetration resistance and the penetration depth are obviously affected by the ratio of the target radius to the projectile radius when the ratio is less than 20, they can not be calculated as an unlimited-size target. When the ratio of the target radius to the projectile radius is larger than 20, the target radius has less effects on the penetration depth and penetration resistance, that can be approximately calculated as an unlimited-size target.
Structure and Dynamics of the VAULT COMPLEX
A. van Zon (Arend)
2004-01-01
textabstractVaults are the largest ribonucleoprotein particles found in eukaryotic cells. The maincomponent of these 13 MDa structures is the Mr 100,000 major vault protein (MVP).In mammalian cells, about 96 copies of this protein are necessary to form one vaultparticle. Two additional proteins are
Designing and building the cork vault
DEFF Research Database (Denmark)
Merritt, Timothy; de Azambuja Varela, Pedro
2014-01-01
Thirty-five students took part in a two-week workshop intended to provide a hands on experience with digital tools for the design and fabrication of a 1:1 scale vault. The two instructors focused on theoretical concepts in arches, vaults, stereotomy, and led exercises of physical construction pro...
49 CFR 192.749 - Vault maintenance.
2010-10-01
... 49 Transportation 3 2010-10-01 2010-10-01 false Vault maintenance. 192.749 Section 192.749 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Maintenance § 192.749 Vault maintenance. (a) Each...
Security analysis for fingerprint fuzzy vaults
Hartloff, Jesse; Bileschi, Maxwell; Tulyakov, Sergey; Dobler, Jimmy; Rudra, Atri; Govindaraju, Venu
2013-05-01
In this work we place some of the traditional biometrics work on fingerprint verification via the fuzzy vault scheme within a cryptographic framework. We show that the breaking of a fuzzy vault leads to decoding of Reed-Solomon codes from random errors, which has been proposed as a hard problem in the cryptography community. We provide a security parameter for the fuzzy vault in terms of the decoding problem, which gives context for the breaking of the fuzzy vault, whereas most of the existing literature measures the strength of the fuzzy vault in terms of its resistance to pre-defined attacks or by the entropy of the vault. We keep track of our security parameter, and provide it alongside ROC statistics. We also aim to be more aware of the nature of the fingerprints when placing them in the fuzzy vault, noting that the distribution of minutiae is far from uniformly random. The results we show provide additional support that the fuzzy vault can be a viable scheme for secure fingerprint verification.
Automatic configuration of modular vault walls
Directory of Open Access Journals (Sweden)
Grković Vladan
2012-01-01
Full Text Available Products such as modular partition walls of vault rooms (with or without vault doors are made at the request of the client who chooses the safety degree and provides the available dimensions of the wall that should be made. Modular construction of vault walls is the system of construction of industrially made elements which are composed in situ, which allows design of products adjusted to individual requirements of clients. Since the vault wall modules repeat in every new project and since they differ only by their number and dimensions, the use of modern CA (Computer Aided tools and the possibility of application of parameter and variant design shorten design time and eliminate possible errors in the process of design of modular vault walls, which reduces the costs of production and increases the level of product quality. The paper presents the procedure for calculation of parameters of parts, modules and the entire vault wall in Microsoft Excel based on which the 3D model of a modular vault wall is automatically configured and developed in software package Autodesk Inventor. [Projekat Ministarstva nauke Republike Srbije, br. TR37020
Ribbed vaults of late Gothic in Sardinia
Directory of Open Access Journals (Sweden)
Paola Casu
2012-06-01
Full Text Available The late Gothic construction practice, settled in the Spanish Mediterranean area, is based on predetermined geometric rules and is shown in religious buildings with ribbed vaults. The proportion between the sides of the area to cover, tracing plan of the ribs as a succession of corner bisectors, stereotomy problems and volumetric aspects, are just some of the elements that can describe the complex construction of a ribbed vault. The aim of this paper is to analyze the dimensional information of the late gothic ribbed vaults of Sardinia, in order to define the geometric and proportional rules for a correct drawing, establishing a standard procedure for the collection of measures and the construction of the 3D model of vaults.
Tile vaulting in the 21st century
Directory of Open Access Journals (Sweden)
D. López López
2016-12-01
Full Text Available New interactive equilibrium methods for the design and analysis of masonry structures have facilitated the construction of masonry structures with a formal language well beyond what is typically associated with compression-only architecture. These developments have also rekindled interest in tile vaulting, and led to a rediscovery of this traditional building technique. To ensure that tile vaults with new, complex shapes can still be built economically, the construction processes involved in the realisation of these structures have adapted. For example, cheaper and simpler falsework systems have been introduced. In addition, a wide variety of materials have been experimented with to be able to build more sustainable vaulted structures with local resources. This paper presents a review of the latest innovations in tile vaulting, based on the most representative works of the past few years with respect to shape, construction method and the use of materials.
On the incompressibility of cylindrical origami patterns
Bös, Friedrich; Gottesman, Omer; Wardetzky, Max
2015-01-01
We investigate the axial compressibility of origami cylinders, i.e., cylindrical structures folded from rectangular sheets of paper. We prove, using geometric arguments, that a general fold pattern only allows for a finite number of isometric cylindrical embeddings. Therefore, compressibility of such structures requires stretching the material or deforming the folds. Our result complements the celebrated "bellows theorem" and extends it to the setting of cylindrical origami whose top and bottom are not necessarily rigid, and severely restricts the space of constructions that must be searched when designing new types of origami-based rigid-foldable deployable structures and metamaterials.
Numerical and experimental analysis of an in-scale masonry cross-vault prototype up to failure
Energy Technology Data Exchange (ETDEWEB)
Rossi, Michela; Calderini, Chiara; Lagomarsino, Sergio [Department of Civil, Chemical and Environmental Engineering, University of Genoa, Via Montallegro 1, Genoa (Italy); Milani, Gabriele [Department of Architecture, Built Environment and Construction Engineering, Milan Polytechnic University, Piazza Leonardo da Vinci 32, Milan (Italy)
2015-12-31
A heterogeneous full 3D non-linear FE approach is validated against experimental results obtained on an in-scale masonry cross vault assembled with dry joints, and subjected to various loading conditions consisting on imposed displacement combinations to the abutments. The FE model relies into a discretization of the blocks by means of few rigid-infinitely resistant parallelepiped elements interacting by means of planar four-noded interfaces, where all the deformation (elastic and inelastic) occurs. The investigated response mechanisms of vault are the shear in-plane distortion and the longitudinal opening and closing mechanism at the abutments. After the validation of the approach on the experimentally tested cross-vault, a sensitivity analysis is conducted on the same geometry, but in real scale, varying mortar joints mechanical properties, in order to furnish useful hints for safety assessment, especially in presence of seismic action.
National Park Service, Department of the Interior — This feature class represents vaults associated with the water infrastructure at Pipe Spring National Monument, Arizona. The vaults data were collected using Trimble...
49 CFR 192.189 - Vaults: Drainage and waterproofing.
2010-10-01
... 49 Transportation 3 2010-10-01 2010-10-01 false Vaults: Drainage and waterproofing. 192.189 Section 192.189 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Components § 192.189 Vaults: Drainage and waterproofing. (a) Each vault must be designed so as to...
Kinematic variables of table vault on artistic gymnastics
Directory of Open Access Journals (Sweden)
Sarah Maria Boldrini FERNANDES
2016-03-01
Full Text Available Abstract The table vault is an event of male and female Artistics Gymnastics. Although it can be performed in a variety of rotations and body positions in different phases, it can be separated in three groups: handspring, Yurchenko and Tsukahara. It is believed that kinematic variables of vault may vary according to group of vault or gymnast body position, but few studies compares the real differences among the three groups of vaults, comparing and describing the variables in different phases. Vault kinematic variables could be diversifying according to the approach or position of the vaulting, but little has been studied about the biomechanical differences, comparing and describing behaviours at different stages. The aim of this study was to organize critical, objective and to systematize the most relevant kinematic variables to performance on vaulting. A Meta analysis over the basis Pubmed, Sport Discus and Web of Science were performed about this issue. From the selected references, we described and analyzed the kinematics of the table vault. Vault can be characterized in seven phases of analysis. Most of the studies are descriptive, and some do not descript all phases. Differences among vault variables according to group vaults, technical level and gender were analysed only in recent studies. There still gaps of knowledge about kinematic variables of table vault, in order to provide comprehensive information about all possibilities of vaults in this gymnastic event. It is concluded that kinematic variables of table vault depends upon vault group and may be considered to the improvement of technical performance. More researches are needed to approach the coaching interface with biomechanics applicable knowledge.
Hazard Evaluation for 244-CR Vault
Energy Technology Data Exchange (ETDEWEB)
GRAMS, W.H.
1999-08-19
This document presents the results of a hazards identification and evaluation performed on the 244-CR Vault to close a USQ (USQ No.TF-98-0785, Potential Inadequacy in Authorization Basis (PIAB): To Evaluate Miscellaneous Facilities Listed In HNF-2503 And Not Addressed In The TWRS Authorization Basis) that was generated as part of an evaluation of inactive TWRS facilities.
Rupture loop annex ion exchange RLAIX vault deactivation
Energy Technology Data Exchange (ETDEWEB)
Ham, J.E.; Harris, D.L., Westinghouse Hanford
1996-08-01
This engineering report documents the deactivation, stabilization and final conditions of the Rupture Loop Annex Ion Exchange (RLAIX) Vault located northwest of the 309 Building`s Plutonium Recycle Test Reactor (PRTR). Twelve ion exchange columns, piping debris, and column liquid were removed from the vault, packaged and shipped for disposal. The vault walls and floor were decontaminated, and portions of the vault were painted to fix loose contamination. Process piping and drains were plugged, and the cover blocks and rain cover were installed. Upon closure,the vault was empty, stabilized, isolated.
E-Area Vault Concrete Material Property And Vault Durability/Degradation Projection Recommendations
Energy Technology Data Exchange (ETDEWEB)
Phifer, M. A.
2014-03-11
Subsequent to the 2008 E-Area Low-Level Waste Facility (ELLWF) Performance Assessment (PA) (WSRC 2008), two additional E-Area vault concrete property testing programs have been conducted (Dixon and Phifer 2010 and SIMCO 2011a) and two additional E-Area vault concrete durability modeling projections have been made (Langton 2009 and SIMCO 2012). All the information/data from these reports has been evaluated and consolidated herein by the Savannah River National Laboratory (SRNL) at the request of Solid Waste Management (SWM) to produce E-Area vault concrete hydraulic and physical property data and vault durability/degradation projection recommendations that are adequately justified for use within associated Special Analyses (SAs) and future PA updates. The Low Activity Waste (LAW) and Intermediate Level (IL) Vaults structural degradation predictions produced by Carey 2006 and Peregoy 2006, respectively, which were used as the basis for the 2008 ELLWF PA, remain valid based upon the results of the E-Area vault concrete durability simulations reported by Langton 2009 and those reported by SIMCO 2012. Therefore revised structural degradation predictions are not required so long as the mean thickness of the closure cap overlying the vaults is no greater than that assumed within Carey 2006 and Peregoy 2006. For the LAW Vault structural degradation prediction (Carey 2006), the mean thickness of the overlying closure cap was taken as nine feet. For the IL Vault structural degradation prediction (Peregoy 2006), the mean thickness of the overlying closure cap was taken as eight feet. The mean closure cap thicknesses as described here for both E-Area Vaults will be included as a key input and assumption (I&A) in the next revision to the closure plan for the ELLWF (Phifer et al. 2009). In addition, it has been identified as new input to the PA model to be assessed in the ongoing update to the new PA Information UDQE (Flach 2013). Once the UDQE is approved, the SWM Key I
Draft Crystal Structure of the Vault Shell at 9-Å Resolution
Anderson, Daniel H; Kickhoefer, Valerie A.; Stuart A Sievers; Rome, Leonard H.; David Eisenberg
2007-01-01
Vaults are the largest known cytoplasmic ribonucleoprotein structures and may function in innate immunity. The vault shell self-assembles from 96 copies of major vault protein and encapsulates two other proteins and a small RNA. We crystallized rat liver vaults and several recombinant vaults, all among the largest non-icosahedral particles to have been crystallized. The best crystals thus far were formed from empty vaults built from a cysteine-tag construct of major vault protein (termed cpMV...
Cranial vault thickness in primates: Homo erectus does not have uniquely thick vault bones.
Copes, Lynn E; Kimbel, William H
2016-01-01
Extremely thick cranial vaults have been noted as a diagnostic characteristic of Homo erectus since the first fossil of the species was identified, but relatively little work has been done on elucidating its etiology or variation across fossils, living humans, or extant non-human primates. Cranial vault thickness (CVT) is not a monolithic trait, and the responsiveness of its layers to environmental stimuli is unknown. We obtained measurements of cranial vault thickness in fossil hominins from the literature and supplemented those data with additional measurements taken on African fossil specimens. Total CVT and the thickness of the cortical and diploë layers individually were compared to measures of CVT in extant species measured from more than 500 CT scans of human and non-human primates. Frontal and parietal CVT in fossil primates was compared to a regression of CVT on cranial capacity calculated for extant species. Even after controlling for cranial capacity, African and Asian H. erectus do not have uniquely high frontal or parietal thickness residuals, either among hominins or extant primates. Extant primates with residual CVT thickness similar to or exceeding H. erectus (depending on the sex and bone analyzed) include Nycticebus coucang, Perodicticus potto, Alouatta caraya, Lophocebus albigena, Galago alleni, Mandrillus sphinx, and Propithecus diadema. However, the especially thick vaults of extant non-human primates that overlap with H. erectus values are composed primarily of cortical bone, while H. erectus and other hominins have diploë-dominated vault bones. Thus, the combination of thick vaults comprised of a thickened diploë layer may be a reliable autapomorphy for members of the genus Homo.
Cylindrically symmetric Einstein-Yang-Mills-Higgs gauge configurations.
Mondaini, R. P.
1985-02-01
Two solutions are obtained for coupled Einstein-Yang-Mills-Higgs fields with cylindrical symmetry and rigid rotation. The Higgs fields are responsible for the creation of singularities and infinite energy densities at the cylinder's axis.
Sea urchin vault structure, composition, and differential localization during development
Directory of Open Access Journals (Sweden)
Dickey-Sims Carrie
2005-02-01
Full Text Available Abstract Background Vaults are intriguing ribonucleoprotein assemblies with an unknown function that are conserved among higher eukaryotes. The Pacific coast sea urchin, Strongylocentrotus purpuratus, is an invertebrate model organism that is evolutionarily closer to humans than Drosophila and C. elegans, neither of which possesses vaults. Here we compare the structures of sea urchin and mammalian vaults and analyze the subcellular distribution of vaults during sea urchin embryogenesis. Results The sequence of the sea urchin major vault protein (MVP was assembled from expressed sequence tags and genome traces, and the predicted protein was found to have 64% identity and 81% similarity to rat MVP. Sea urchin MVP includes seven ~50 residue repeats in the N-terminal half of the protein and a predicted coiled coil domain in the C-terminus, as does rat MVP. A cryoelectron microscopy (cryoEM reconstruction of isolated sea urchin vaults reveals the assembly to have a barrel-shaped external structure that is nearly identical to the rat vault structure. Analysis of the molecular composition of the sea urchin vault indicates that it contains components that may be homologs of the mammalian vault RNA component (vRNA and protein components (VPARP and TEP1. The sea urchin vault appears to have additional protein components in the molecular weight range of 14–55 kDa that might correspond to molecular contents. Confocal experiments indicate a dramatic relocalization of MVP from the cytoplasm to the nucleus during sea urchin embryogenesis. Conclusions These results are suggestive of a role for the vault in delivering macromolecules to the nucleus during development.
CLEARANCE OF ARCHIVE TAPE VAULT (BUILDING 186)
EP Division
1999-01-01
The archive tape vault is being cleared to make way for the LHC experiments silicon facility.Experiments were contacted in February to arrange for the extended storage or destruction of archived volumes. Any who have not yet done so are asked to contactR. Minchin/IT immediately.This is also an opportunity to clear unused tapes or cartridges from around the site and have them destroyed ecologically. Please contact ep.smi.helpdesk@cern.ch to arrange for collection.A.E. Ball/EP-SMI
Realization of correlation attack against the fuzzy vault scheme
Kholmatov, Alisher; Yanikoglu, Berrin
2008-02-01
User privacy and template security are major concerns in the use of biometric systems. These are serious concerns based on the fact that once compromised, biometric traits can not be canceled or reissued. The Fuzzy Vault scheme has emerged as a promising method to alleviate the template security problem. The scheme is based on binding the biometric template with a secret key and scrambling it with a large amount of redundant data, such that it is computationally infeasible to extract the secret key without possession of the biometric trait. It was recently claimed that the scheme is susceptible to correlation based attacks which assume the availability of two fuzzy vaults created using the same biometric data (e.g. two impressions of the same fingerprint) and suggests that correlating them would reveal the biometric data hidden inside. In this work, we implemented the fuzzy vault scheme using fingerprints and performed correlation attacks against a database of 400 fuzzy vaults (200 matching pairs). Given two matching vaults, we could successfully unlock 59% of them within a short time. Furthermore, it was possible to link an unknown vault to a short list containing its matching pair, for 41% of all vaults. These results prove the claim that the fuzzy vault scheme without additional security measures is indeed vulnerable to correlation attacks.
Increasing the load bearing capacity of barrel vaults
Kamerling, M.W.
2011-01-01
Just after World War II many barrel vaults and domes were built with a structural system, known as Fusée Ceramique. This paper analyses the load bearing capacity of these vaults. Schemes, theories, idealizations and assumptions are analysed, validated and discussed. Methods to increase the load bear
Geometric principles in additive systems for construction of vaults
DEFF Research Database (Denmark)
Jaeger, Thomas Arvid
2015-01-01
Abstract Vaults and shell constructions are among the most fascinating elements in architecture. Covering large spaces has always been a challenge in architecture and engineering and the vault with curved and double curved form has a special significance. Throughout the history of Christianity...... della Fiore. The Barouque style followed with the domes of Borromini; Bernini and Guarini. The Period of Enlightenment had iconic tunnel- and dome vault projects by Etienne l. Boulée. All these stone vaults were made by additive systems in bricks and mortar. In the 20.th century concrete was introduced...... and the reinforced concrete made new large spans possible. These was in-situ casted and not additive systems. Utzon’s Sydney opera house from the mid-fifties combined the additive system, iron reinforcement and concrete into at new prefabricated vault system, which could handle the complex geometry of the shells...
Complications of rigid internal fixation.
Campbell, Chris A; Lin, Kant Y
2009-03-01
Over the past 20 years, there have been many advances in the development of bone fixation systems used in the practice of craniomaxillofacial surgery. As surgical practices have evolved, the complications of each technologic advance have changed accordingly. Interfragmentary instability of interosseous wiring has been replaced by the risk of exposure, infection, and palpability of plate and screw fixation systems. The improved rigidity of plate fixation requires anatomic alignment of fracture fragments. Failure to obtain proper alignment has led to the phenomenon known as "open internal fixation" of fracture fragments without proper reduction. The size of the plates has decreased to minimize palpability and exposure. However limitations in their application have been encountered due to the physiologic forces of the muscles of mastication and bone healing. In the pediatric population, the long-standing presence of plates in the cranial vault resulted in reports of transcranial migration and growth restriction. These findings led to the development of resorbable plating systems, which are associated with self-limited plate palpability and soft tissue inflammatory reactions. Any rigid system including these produces growth restriction in varying amounts. In this discussion, we review the reported complication rates of miniplating and microplating systems as well as absorptive plating systems in elective and traumatic craniofacial surgery.
Posthysterectomy vault prolapse of vaginal walls: Choice of operating procedure
Directory of Open Access Journals (Sweden)
Argirović Rajka
2012-01-01
Full Text Available Post-hysterectomy vaginal vault prolapse is a common complication following different types of hysterectomy with a negative impact on the woman’s quality of life due to associated urinary, anorectal and sexual dysfunction. A clear understanding of the supporting mechanisms for the uterus and vagina is important in order to make the right choice of the corrective procedure and also to minimize the risk of posthysterectomy occurrence of vault prolapse. Preexisting pelvic floor defect prior to hysterectomy is the single most important risk factor for vault prolapse. Various surgical techniques have been advanced in hysterectomy to prevent vault prolapse. Vaginal vault repair can be carried out abdominally or vaginally. Sacrospinous fixation and abdominal sacrocolpopexy are the commonly performed procedures. The vaginal approach for vault prolapse is superior to the abdominal approach in terms of complication rates, blood loss, postoperative discomfort, length of hospital stay and costeffectiveness. Moreover, it allows the simultaneous repair of all coexistent pelvic floor defects, such as cystocele, enterocele and rectocele. Abdominal sacrocolpopexy is associated with a lower rate of recurrent vault prolapse and dyspareunia than the vaginal sacrospinous colpopexy. Other less commonly performed procedures include uterosacral ligament suspension and illeococcygeal fixation with a high risk of ureteric injury. Surgical mesh of non-absorbent material is gaining in popularity and preliminary data from vaginal mesh procedures is encouraging.
Pilonidal cyst on the vault: case report
Directory of Open Access Journals (Sweden)
BORGES GUILHERME
1999-01-01
Full Text Available Pilonidal cysts and sinuses are described as dermoid cysts which contain follicles of hairs and sebaceous glands. They clinically present as a classic case of inflammation which comes with pain, local infection and redness. The origin of pilonidal disease remains controverse. There are many hypothesis as lack of hygiene on the affected area and a penetration and growth of a hair in the subcutaneus tissue caused by constant friction or direct trauma on the damaged area. The option for clinical treatment is very frequent. However, taking into consideration the incidence and the possibility of recidive, surgical treatment is presently recommended. Complications include cellulitis and abscess formation. Pilonidal cysts are mostly found on the sacral region. In the literature is found description of pilonidal cysts on the penis, interdigital region on the hands as well as on the cervical region. We present a case of pilonidal cyst located on the vault biparietal region, without malignant degeneration.
Data Vaults: Database Technology for Scientific File Repositories
Ivanova, Milena; Kersten, Martin; Manegold, Stefan; Kargin, Yagiz
2013-01-01
Current data-management systems and analysis tools fail to meet scientists’ data-intensive needs. A "data vault" approach lets researchers effectively and efficiently explore and analyze information.
DISPERSION OF CYLINDRICAL PARTICLES IN TURBULENT FLOWS
Institute of Scientific and Technical Information of China (English)
GAO Zhen-yu; LIN Jian-zhong
2004-01-01
With consideration of the Stokes drag and virtual mass force, the equations for mean and fluctuating velocities in rotation and translation were given for rigid cylindrical particles moving in a turbulent flow. Then the rotational and translational dispersion coefficients of particle were derived. The relationships between the dispersion coefficients and flow length scale as well as particle characteristic parameters were analyzed. The resulting dispersion coefficients were proved to decrease as the particle length increases. The conclusions are helpful for the further research on the motion of cylindrical particles in turbulent flows.
Optimal technique for maximal forward rotating vaults in men's gymnastics.
Hiley, Michael J; Jackson, Monique I; Yeadon, Maurice R
2015-08-01
In vaulting a gymnast must generate sufficient linear and angular momentum during the approach and table contact to complete the rotational requirements in the post-flight phase. This study investigated the optimization of table touchdown conditions and table contact technique for the maximization of rotation potential for forwards rotating vaults. A planar seven-segment torque-driven computer simulation model of the contact phase in vaulting was evaluated by varying joint torque activation time histories to match three performances of a handspring double somersault vault by an elite gymnast. The closest matching simulation was used as a starting point to maximize post-flight rotation potential (the product of angular momentum and flight time) for a forwards rotating vault. It was found that the maximized rotation potential was sufficient to produce a handspring double piked somersault vault. The corresponding optimal touchdown configuration exhibited hip flexion in contrast to the hyperextended configuration required for maximal height. Increasing touchdown velocity and angular momentum lead to additional post-flight rotation potential. By increasing the horizontal velocity at table touchdown, within limits obtained from recorded performances, the handspring double somersault tucked with one and a half twists, and the handspring triple somersault tucked became theoretically possible. Copyright © 2015 Elsevier B.V. All rights reserved.
Studing cranial vault modifications in ancient Mesoamerica.
Tiesler, Vera
2012-01-01
The artificial modification of infant cranial vaults through massages or by means of constriction and compression devices constitutes a readily visible, permanent body modification that has been employed cross-culturally to express identity, ethnicity, beauty, status and gender. For those ancient societies that staged head shaping, these cultural correlates may be ascertained by examining cranial shapes together with other data sets from the archaeological record. Studies of skulls modified for cultural reasons also provide important clues for understanding principles in neural growth and physiopathological variation in cranial expansion. This paper focuses on head shaping techniques in Mesoamerica, where the practice was deeply rooted and widespread before the European conquest. It provides a comprehensive review of the Mesoamericanistic research on shaping techniques, implements and taxonomies. An up-dated, interdisciplinary examination of the physiological implications and the cultural meanings of artificially produced head shapes in different times and culture areas within Mesoamerica leads to a discussion of the scope, caveats, and future directions involved in this kind of research in the region and beyond.
Data Vault: providing simple web access to NRAO data archives
DuPlain, Ron; Benson, John; Sessoms, Eric
2008-08-01
In late 2007, the National Radio Astronomy Observatory (NRAO) launched Data Vault, a feature-rich web application for simplified access to NRAO data archives. This application allows users to submit a Google-like free-text search, and browse, download, and view further information on matching telescope data. Data Vault uses the model-view-controller design pattern with web.py, a minimalist open-source web framework built with the Python Programming Language. Data Vault implements an Ajax client built on the Google Web Toolkit (GWT), which creates structured JavaScript applications. This application supports plug-ins for linking data to additional web tools and services, including Google Sky. NRAO sought the inspiration of Google's remarkably elegant user interface and notable performance to create a modern search tool for the NRAO science data archive, taking advantage of the rapid development frameworks of web.py and GWT to create a web application on a short timeline, while providing modular, easily maintainable code. Data Vault provides users with a NRAO-focused data archive while linking to and providing more information wherever possible. Free-text search capabilities are possible (and even simple) with an innovative query parser. NRAO develops all software under an open-source license; Data Vault is available to developers and users alike.
Neutron monitoring of plutonium at the ZPPR storage vault
Energy Technology Data Exchange (ETDEWEB)
Caldwell, J.T.; Kuckertz, T.H.; Bieri, J.M.; France, S.W.; Goin, R.W.; Hastings, R.D.; Pratt, J.C.; Shunk, E.R.
1981-12-01
We investigated a method for monitoring a typical large storage vault for unauthorized removal of plutonium. The method is based on the assumption that the neutron field in a vault produced by a particular geometric configuration of bulk plutonium remains constant in time and space as long as the configuration is undisturbed. To observe such a neutron field, we installed an array of 25 neutron detectors in the ceiling of a plutonium storage vault at Argonne National Laboratory West. Each neutron detector provided an independent spatial measurement of the vault neutron field. Data collected by each detector were processed to determine whether statistically significant changes had occurred in the neutron field. Continuous observation experiments measured the long-term stability of the system. Removal experiments were performed in which known quantities of plutonium were removed from the vault. Both types of experiments demonstrated that the neutron monitoring system can detect removal or addition of bulk plutonium (11% /sup 240/Pu) whose mass is as small as 0.04% of the total inventory.
Wind Pressure Distribution and Wind-induced Dynamic Response for Spatial Groined Latticed Vaults
Institute of Scientific and Technical Information of China (English)
MA Jun; ZHOU Dai; BAO Yan
2008-01-01
The wind pressure distribution and wind-induced vibration responses of long-span spatial groined latticed vaults (SGLVs) were numerically simulated, which always are ones of the most important problems in the structural wind resistance design. Incompressible visco-fluid model was introduced, and the standard k-εtwo equation model and semi-implicit method for pressure linked equation (SIMPLE) were used to describe the flow turbulence. Furthermore, the structural dynamic equation was set up, which is solved by Newmark-β method. And several sort of wind-induced vibration coefficients such as the wind-induced vibration coefficient corresponding to the nodal displacement responses and wind loads were suggested. In the numerical simulation where the SGLV consisting of the cylindrical sectors with different curved surface was chosen as the example,the influence on the relative wind pressure distribution and structural wind-induced vibration responses of the closed or open SGLV caused by such parameters as the number of cylindrical sectors, structural curvature and the ratio of rise to span was investigated. Finally, some useful conclusions on the local wind pressure distribution on the structural surface and the wind-induced vibration coefficients of SGLV were developed.
Super-light pearl-chain arch vaults
DEFF Research Database (Denmark)
Hertz, Kristian Dahl; Halding, Philip Skov
2014-01-01
in the vault. This means that the structure can sustain 4 hours standard fire. That it has a very high level of sound insulation, efficient sound damping properties, optimized production, a low production of CO2 that has already given rise to several awards, and easy transport of plane elements instead of what......Arch vaults are known as optimal and impressive structures, but due to their curved shapes they are extremely costly to produce in countries, where the cost of labor is high. By means of super-light pearl-chain technology arch vaults can be constructed from equal plane prefabricated elements, which...... are assembled on the erection site by means of post-tensioning and lifted in place in buildings and bridges. The super-light SL-deck element is developed by the company Abeo Ltd and The Technical University of Denmark for plane floor structures in buildings. However, this deck element is designed in such a way...
Performance of the Fuzzy Vault for Multiple Fingerprints (Extended Version)
Merkle, Johannes; Korte, Ulrike; Niesing, Matthias; Schwaiger, Michael
2010-01-01
The fuzzy vault is an error tolerant authentication method that ensures the privacy of the stored reference data. Several publications have proposed the application of the fuzzy vault to fingerprints, but the results of subsequent analyses indicate that a single finger does not contain sufficient information for a secure implementation. In this contribution, we present an implementation of a fuzzy vault based on minutiae information in several fingerprints aiming at a security level comparable to current cryptographic applications. We analyze and empirically evaluate the security, efficiency, and robustness of the construction and several optimizations. The results allow an assessment of the capacity of the scheme and an appropriate selection of parameters. Finally, we report on a practical simulation conducted with ten users.
HYDRAULIC AND PHYSICAL PROPERTIES OF SALTSTONE GROUTS AND VAULT CONCRETES
Energy Technology Data Exchange (ETDEWEB)
Dixon, K; John Harbour, J; Mark Phifer, M
2008-11-25
The Saltstone Disposal Facility (SDF), located in the Z-Area of the Savannah River Site (SRS), is used for the disposal of low-level radioactive salt solution. The SDF currently contains two vaults: Vault 1 (6 cells) and Vault 4 (12 cells). Additional disposal cells are currently in the design phase. The individual cells of the saltstone facility are filled with saltstone. Saltstone is produced by mixing the low-level radioactive salt solution, with blast furnace slag, fly ash, and cement (dry premix) to form a dense, micro-porous, monolithic, low-level radioactive waste form. The saltstone is pumped into the disposal cells where it subsequently solidifies. Significant effort has been undertaken to accurately model the movement of water and contaminants through the facility. Key to this effort is an accurate understanding of the hydraulic and physical properties of the solidified saltstone. To date, limited testing has been conducted to characterize the saltstone. The primary focus of this task was to estimate the hydraulic and physical properties of three types of saltstone and two vault concretes. The saltstone formulations included saltstone premix batched with (1) Deliquification, Dissolution, and Adjustment (DDA) salt simulant (w/pm 0.60), (2) Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) salt simulant (w/pm 0.60), and (3) Salt Waste Processing Facility (SWPF) salt simulant (w/pm 0.60). The vault concrete formulations tested included the Vault 1/4 concrete and two variations of the Vault 2 concrete (Mix 1 and Mix 2). Wet properties measured for the saltstone formulations included yield stress, plastic viscosity, wet unit weight, bleed water volume, gel time, set time, and heat of hydration. Hydraulic and physical properties measured on the cured saltstone and concrete samples included saturated hydraulic conductivity, moisture retention, compressive strength, porosity, particle density, and dry bulk density. These properties
Gortler, Steven J; Liu, Ligang; Thurston, Dylan P
2010-01-01
We study the properties of affine rigidity of a hypergraph and prove a variety of fundamental results. First, we show that affine rigidity is a generic property (i.e., depends only on the hypergraph, not the particular embedding). Then we prove that a graph is generically neighborhood affinely rigid in d-dimensional space if it is (d+1)-vertex-connected. We also show neighborhood affine rigidity of a graph implies universal rigidity of its squared graph. Our results, and affine rigidity more generally, have natural applications in point registration and localization, as well as connections to manifold learning.
Directory of Open Access Journals (Sweden)
Steven J. Gortler
2013-12-01
Full Text Available We study the properties of affine rigidity of a hypergraph and prove a variety of fundamental results. First, we show that affine rigidity is a generic property (i.e., depends only on the hypergraph, not the particular embedding. Then we prove that a graph is generically neighborhood affinely rigid in d-dimensional space if it is (d+1-vertex-connected. We also show neighborhood affine rigidity of a graph implies universal rigidity of its squared graph. Our results, and affine rigidity more generally, have natural applications in point registration and localization, as well as connections to manifold learning.
Overexpression of the human major vault protein in gangliogliomas.
Aronica, E; Gorter, J.A.; Vliet, van EA; Spliet, WG; Veelen, van CW; Rijen, van PC; Leenstra, S.; Ramkema, MD; Scheffer, G.L.; Scheper, R.J.; Sisodiya, SM; Troost, D.
2003-01-01
PURPOSE: Recent evidence has been obtained that the major vault protein (MVP) may play a role in multidrug resistance (MDR). We investigated the expression and cellular localization of MVP in gangliogliomas (GGs), which are increasingly recognized causes of chronic pharmacoresistant epilepsy. METHOD
In situ investigations of vault paintings in the Antwerp cathedral.
Deneckere, Annelien; Schudel, Walter; Van Bos, Marina; Wouters, Helena; Bergmans, Anna; Vandenabeele, Peter; Moens, Luc
2010-02-01
X-ray fluorescence spectroscopy (XRF) and Raman spectroscopy have been used to examine 15th century mediaeval and 16th century renaissance vault paintings in the Our Lady's Cathedral (Antwerp, Belgium) in view of their restoration. The use of mobile instruments made it possible to work totally non-destructively. This complementary approach yields information on the elemental (XRF) and on the molecular composition (Raman) of the pigments. For the 15th century vault painting the pigments lead-tin yellow (Pb(2)SnO(4)), lead white (2PbCO(3)xPb(OH)(2)), vermilion (HgS), massicot (PbO) and azurite (2CuCO(3).Cu(OH)(2)) could be identified. The pigments used for the 16th century vault painting could be identified as red lead (Pb(3)O(4)), hematite (Fe(2)O(3)), lead white (2PbCO(3)xPb(OH)(2)) and azurite (2CuCO(3)xCu(OH)(2)). For both paintings the presence of the strong Raman scatterer calcite (CaCO(3)) resulted in a difficult identification of the pigments by Raman spectroscopy. The presence of gypsum (CaSO(4)x2H(2)O) on the mediaeval vault painting probably indicates that degradation took place.
Draft crystal structure of the vault shell at 9-A resolution.
Directory of Open Access Journals (Sweden)
Daniel H Anderson
2007-11-01
Full Text Available Vaults are the largest known cytoplasmic ribonucleoprotein structures and may function in innate immunity. The vault shell self-assembles from 96 copies of major vault protein and encapsulates two other proteins and a small RNA. We crystallized rat liver vaults and several recombinant vaults, all among the largest non-icosahedral particles to have been crystallized. The best crystals thus far were formed from empty vaults built from a cysteine-tag construct of major vault protein (termed cpMVP vaults, diffracting to about 9-A resolution. The asymmetric unit contains a half vault of molecular mass 4.65 MDa. X-ray phasing was initiated by molecular replacement, using density from cryo-electron microscopy (cryo-EM. Phases were improved by density modification, including concentric 24- and 48-fold rotational symmetry averaging. From this, the continuous cryo-EM electron density separated into domain-like blocks. A draft atomic model of cpMVP was fit to this improved density from 15 domain models. Three domains were adapted from a nuclear magnetic resonance substructure. Nine domain models originated in ab initio tertiary structure prediction. Three C-terminal domains were built by fitting poly-alanine to the electron density. Locations of loops in this model provide sites to test vault functions and to exploit vaults as nanocapsules.
Draft crystal structure of the vault shell at 9-A resolution.
Anderson, Daniel H; Kickhoefer, Valerie A; Sievers, Stuart A; Rome, Leonard H; Eisenberg, David
2007-11-01
Vaults are the largest known cytoplasmic ribonucleoprotein structures and may function in innate immunity. The vault shell self-assembles from 96 copies of major vault protein and encapsulates two other proteins and a small RNA. We crystallized rat liver vaults and several recombinant vaults, all among the largest non-icosahedral particles to have been crystallized. The best crystals thus far were formed from empty vaults built from a cysteine-tag construct of major vault protein (termed cpMVP vaults), diffracting to about 9-A resolution. The asymmetric unit contains a half vault of molecular mass 4.65 MDa. X-ray phasing was initiated by molecular replacement, using density from cryo-electron microscopy (cryo-EM). Phases were improved by density modification, including concentric 24- and 48-fold rotational symmetry averaging. From this, the continuous cryo-EM electron density separated into domain-like blocks. A draft atomic model of cpMVP was fit to this improved density from 15 domain models. Three domains were adapted from a nuclear magnetic resonance substructure. Nine domain models originated in ab initio tertiary structure prediction. Three C-terminal domains were built by fitting poly-alanine to the electron density. Locations of loops in this model provide sites to test vault functions and to exploit vaults as nanocapsules.
DEFF Research Database (Denmark)
Rörig-Dalgaard, Inge; Bøllingtoft, P.
2011-01-01
Salt induced deterioration of the vault in Rørby Church has resulted in extensive deterioration of the vault itself and of the murals on the lower surface of the vault. The upper surface of the vault has previously been covered with cement mortar. After removing this cement mortar some of the bri...
DEFF Research Database (Denmark)
Rörig-Dalgaard, Inge; Bøllingtoft, P.
2011-01-01
Salt induced deterioration of the vault in Rørby Church has resulted in extensive deterioration of the vault itself and of the murals on the lower surface of the vault. The upper surface of the vault has previously been covered with cement mortar. After removing this cement mortar some of the bri...
Estimation of the hybrid lens parameters through rigid gas permeable lens fitting
Hasani, Mohammadali; Hashemi, Hassan; Jafarzadehpur, Ebrahim; Yekta, Abbas Ali; Dadbin, Nooshin; khabazkhoob, Mehdi
2016-01-01
Purpose To estimate the fitting parameters of the hybrid contact lens in patients with corneal ectasia using the rigid gas permeable (RGP) lens. Methods Thirty-four eyes with corneal ectasia were evaluated in this study. The patients were examined once with the RGP lens and once with the hybrid contact lens. The relationship between the base curvature of the RGP and the vault of the hybrid lens and the correlation between their powers were analyzed. Results We found a linear relationship betw...
Special Analysis: Revision of Saltstone Vault 4 Disposal Limits (U)
Energy Technology Data Exchange (ETDEWEB)
Cook, J
2005-05-26
New disposal limits have been computed for Vault 4 of the Saltstone Disposal Facility based on several revisions to the models in the existing Performance Assessment and the Special Analysis issued in 2002. The most important changes are the use of a more rigorous groundwater flow and transport model, and consideration of radon emanation. Other revisions include refinement of the aquifer mesh to more accurately model the footprint of the vault, a new plutonium chemistry model accounting for the different transport properties of oxidation states III/IV and V/VI, use of variable infiltration rates to simulate degradation of the closure system, explicit calculation of gaseous releases and consideration of the effects of settlement and seismic activity on the vault structure. The disposal limits have been compared with the projected total inventory expected to be disposed in Vault 4. The resulting sum-of-fractions of the 1000-year disposal limits is 0.2, which indicates that the performance objectives and requirements of DOE 435.1 will not be exceeded. This SA has not altered the conceptual model (i.e., migration of radionuclides from the Saltstone waste form and Vault 4 to the environment via the processes of diffusion and advection) of the Saltstone PA (MMES 1992) nor has it altered the conclusions of the PA (i.e., disposal of the proposed waste in the SDF will meet DOE performance measures). Thus a PA revision is not required and this SA serves to update the disposal limits for Vault 4. In addition, projected doses have been calculated for comparison with the performance objectives laid out in 10 CFR 61. These doses are 0.05 mrem/year to a member of the public and 21.5 mrem/year to an inadvertent intruder in the resident scenario over a 10,000-year time-frame, which demonstrates that the 10 CFR 61 performance objectives will not be exceeded. This SA supplements the Saltstone PA and supersedes the two previous SAs (Cook et al. 2002; Cook and Kaplan 2003).
Zon, van A; Mossink, MH; Schoester, M.; Scheper, R.J.; Sonneveld, P.; Wiemer, EA
2004-01-01
Vaults may contribute to multidrug resistance by transporting drugs away from their subcellular targets. To study the involvement of vaults in the extrusion of anthracyclines from the nucleus, we investigated the handling of daunorubicin by drug-sensitive and drug-resistant non-small lung cancer cel
Accounting for cranial vault growth in experimental design.
Power, Stephanie M; Matic, Damir B; Holdsworth, David W
2014-05-01
Earlier studies have not accounted for continued growth when using the rat calvarial defect model to evaluate bone healing in vivo. The purpose of this study was: 1) to calculate rat cranial vault growth over time; and 2) to determine the effects of accounting for growth on defect healing. Bilateral parietal defects were created in 10 adult Wistar rats. Serial microscopic computerized tomography scans were performed. Bone mineral content (BMC) measured according to standard technique and repeated accounting for cranial growth over time was compared with the use of parametric and nonparametric tests. Cranial vault growth continued through 22 weeks of age, increasing 7.5% in width and 9.1% in length, and calvarial defects expanded proportionately. BMC was greater within defects accounting for growth 2-12 weeks postoperatively (P accounting for cranial growth given advances in serial imaging techniques. Crown Copyright © 2014. Published by Mosby, Inc. All rights reserved.
Stability analysis of cylindrical Vlasov equilibria
Energy Technology Data Exchange (ETDEWEB)
Short, R.W.
1979-01-01
A general method of stability analysis is described which may be applied to a large class of such problems, namely those which are described dynamically by the Vlasov equation, and geometrically by cylindrical symmetry. The method is presented for the simple case of the Vlasov-Poisson (electrostatic) equations, and the results are applied to a calculation of the lower-hybrid-drift instability in a plasma with a rigid rotor distribution function. The method is extended to the full Vlasov-Maxwell (electromagnetic) equations. These results are applied to a calculation of the instability of the extraordinary electromagnetic mode in a relativistic E-layer interacting with a background plasma.
PHASE II VAULT TESTING OF THE ARGONNE RFID SYSTEM
Energy Technology Data Exchange (ETDEWEB)
Willoner, T.; Turlington, R.; Koenig, R.
2012-06-25
The U.S. Department of Energy (DOE) (Environmental Management [EM], Office of Packaging and Transportation [EM-45]) Packaging and Certification Program (DOE PCP) has developed a Radio Frequency Identification (RFID) tracking and monitoring system, called ARG-US, for the management of nuclear materials packages during transportation and storage. The performance of the ARG-US RFID equipment and system has been fully tested in two demonstration projects in April 2008 and August 2009. With the strong support of DOE-SR and DOE PCP, a field testing program was completed in Savannah River Site's K-Area Material Storage (KAMS) Facility, an active Category I Plutonium Storage Facility, in 2010. As the next step (Phase II) of continued vault testing for the ARG-US system, the Savannah River Site K Area Material Storage facility has placed the ARG-US RFIDs into the 910B storage vault for operational testing. This latest version (Mark III) of the Argonne RFID system now has the capability to measure radiation dose and dose rate. This paper will report field testing progress of the ARG-US RFID equipment in KAMS, the operability and reliability trend results associated with the applications of the system, and discuss the potential benefits in enhancing safety, security and materials accountability. The purpose of this Phase II K Area test is to verify the accuracy of the radiation monitoring and proper functionality of the ARG-US RFID equipment and system under a realistic environment in the KAMS facility. Deploying the ARG-US RFID system leads to a reduced need for manned surveillance and increased inventory periods by providing real-time access to status and event history traceability, including environmental condition monitoring and radiation monitoring. The successful completion of the testing program will provide field data to support a future development and testing. This will increase Operation efficiency and cost effectiveness for vault operation. As the next step
The Acoustics of the Double Elliptical Vault of the Royal Palace of Caserta (Italy)
Umberto Berardi; Gino Iannace; Amelia Trematerra
2017-01-01
This work investigates the acoustic characteristics of the double elliptical vault, which overlooks the Grand Staircase of the Royal Palace of Caserta (Italy). The Royal Palace was built by the architect Luigi Vanvitelli in the Seventeenth Century and it is the largest royal building in Italy. The double elliptical vault presents a great scenography effect. Inside the vault, on the planking level, musicians used to play for the king and his guests when the royal procession, going up the grand...
Clark, Timothy B P
2011-01-01
In this paper we investigate the class of rigid monomial ideals. We give a characterization of the minimal free resolutions of certain classes of these ideals. Specifically, we show that the ideals in a particular subclass of rigid monomial ideals are lattice-linear and thus their minimal resolution can be constructed as a poset resolution. We then use this result to give a description of the minimal free resolution of a larger class of rigid monomial ideals by using $\\mathcal{L}(n)$, the lattice of all lcm-lattices of monomial ideals with $n$ generators. By fixing a stratum in $\\mathcal{L}(n)$ where all ideals have the same total Betti numbers we show that rigidity is a property which is upward closed in $\\mathcal{L}(n)$. Furthermore, the minimal resolution of all rigid ideals contained in a fixed stratum is shown to be isomorphic to the constructed minimal resolution.
Bioengineered Vaults: Self-Assembling Protein Shell–Lipophilic Core Nanoparticles for Drug Delivery
2015-01-01
We report a novel approach to a new class of bioengineered, monodispersed, self-assembling vault nanoparticles consisting of a protein shell exterior with a lipophilic core interior designed for drug and probe delivery. Recombinant vaults were engineered to contain a small amphipathic α-helix derived from the nonstructural protein 5A of hepatitis C virus, thereby creating within the vault lumen a lipophilic microenvironment into which lipophilic compounds could be reversibly encapsulated. Multiple types of electron microscopy showed that attachment of this peptide resulted in larger than expected additional mass internalized within the vault lumen attributable to incorporation of host lipid membrane constituents spanning the vault waist (>35 nm). These bioengineered lipophilic vaults reversibly associate with a sample set of therapeutic compounds, including all-trans retinoic acid, amphotericin B, and bryostatin 1, incorporating hundreds to thousands of drug molecules per vault nanoparticle. Bryostatin 1 is of particular therapeutic interest because of its ability to potently induce expression of latent HIV, thus representing a preclinical lead in efforts to eradicate HIV/AIDS. Vaults loaded with bryostatin 1 released free drug, resulting in activation of HIV from provirus latency in vitro and induction of CD69 biomarker expression following intravenous injection into mice. The ability to preferentially and reversibly encapsulate lipophilic compounds into these novel bioengineered vault nanoparticles greatly advances their potential use as drug delivery systems. PMID:25061969
The Fuzzy Vault for fingerprints is Vulnerable to Brute Force Attack
Mihailescu, Preda
2007-01-01
The \\textit{fuzzy vault} approach is one of the best studied and well accepted ideas for binding cryptographic security into biometric authentication. The vault has been implemented in connection with fingerprint data by Uludag and Jain. We show that this instance of the vault is vulnerable to brute force attack. An interceptor of the vault data can recover both secret and template data using only generally affordable computational resources. Some possible alternatives are then discussed and it is suggested that cryptographic security may be preferable to the one - way function approach to biometric security.
An automated magnetic tape vault at CERN computer center
Claudia Marcelloni
2008-01-01
The rapidly changing data processing landscape the underlying long-term storage technology remains the tried and tested magnetic tape. This robust and mature technology is used to store the complete LHC data set, from which a fraction of the data is copied to overlying disk caches for fast and widespread access. The handling of the magnetic tape cartridges is now fully automated, as they are racked in vaults where they are moved between the storage shelves and the tape drives by robotic arms.
Microfabricated cylindrical ion trap
Blain, Matthew G.
2005-03-22
A microscale cylindrical ion trap, having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale cylindrical ion trap to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The microscale CIT has a reduced ion mean free path, allowing operation at higher pressures with less expensive and less bulky vacuum pumping system, and with lower battery power than conventional- and miniature-sized ion traps. The reduced electrode voltage enables integration of the microscale cylindrical ion trap with on-chip integrated circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of microscale cylindrical ion traps can be realized in truly field portable, handheld microanalysis systems.
HOMOLOGY RIGIDITY OF GRASSMANNIANS
Institute of Scientific and Technical Information of China (English)
Li Fang; Duan Haibao
2009-01-01
Applying the theory of GrSbner basis to the Schubert presentation for the cohomology of Grassmannians [2], we extend the homology rigidity results known for the classical Grassmaniaas to the exceptional cases.
Risk Management in the Original Extreme Sporting Event: The Pole Vault
Bemiller, Jim; Hardin, Robin
2010-01-01
The pole vault was considered the ultimate test of physical ability and daring before the advent of modern extreme sports such as skateboarding, snowboarding, and mountain biking. The inherent risks of the pole vault have been well documented. The National Center for Catastrophic Sport Injury Research reported in 2007 that the catastrophic injury…
Cleanup Verification Package for the 118-F-7, 100-F Miscellaneous Hardware Storage Vault
Energy Technology Data Exchange (ETDEWEB)
M. J. Appel
2006-11-02
This cleanup verification package documents completion of remedial action for the 118-F-7, 100-F Miscellaneous Hardware Storage Vault. The site consisted of an inactive solid waste storage vault used for temporary storage of slightly contaminated reactor parts that could be recovered and reused for the 100-F Area reactor operations.
Effect of Materials and Manufacturing on the Bending Stiffness of Vaulting Poles
Davis, C. L.; Kukureka, S. N.
2012-01-01
The increase in the world record height achieved in pole vaulting can be related to the improved ability of the athletes, in terms of their fitness and technique, and to the change in materials used to construct the pole. For example in 1960 there was a change in vaulting pole construction from bamboo to glass fibre reinforced polymer (GFRP)…
Lötsch, Daniela; Steiner, Elisabeth; Holzmann, Klaus; Spiegl-Kreinecker, Sabine; Pirker, Christine; Hlavaty, Juraj; Petznek, Helga; Hegedus, Balazs; Garay, Tamas; Mohr, Thomas; Sommergruber, Wolfgang; Grusch, Michael; Berger, Walter
2013-01-01
Despite their ubiquitous expression and high conservation during evolution, precise cellular functions of vault ribonucleoparticles, mainly built of multiple major vault protein (MVP) copies, are still enigmatic. With regard to cancer, vaults were shown to be upregulated during drug resistance development as well as malignant transformation and progression. Such in a previous study we demonstrated that human astrocytic brain tumours including glioblastoma are generally high in vault levels wh...
Catapult effect in pole vaulting: is muscle coordination determinant?
Frère, Julien; Göpfert, Beat; Hug, François; Slawinski, Jean; Tourny-Chollet, Claire
2012-02-01
This study focused on the phase between the time of straightened pole and the maximum height (HP) of vaulter and aimed at determining the catapult effect in pole vaulting on HP. Seven experienced vaulters performed 5-10 vaults recorded by two video cameras, while the surface electromyography (sEMG) activity of 10 upper limbs muscles was recorded. HP was compared with an estimated maximum height (HP(est)) allowing the computation of a push-off index. Muscle synergies were extracted from the sEMG activity profiles using a non-negative matrix factorization algorithm. No significant difference (p>0.47) was found between HP(est) (4.64±0.21m) and HP (4.69±0.23m). Despite a high inter-individual variability in sEMG profiles, two muscle synergies were extracted for all the subjects which accounted for 96.1±2.9% of the total variance. While, the synergy activation coefficients were very similar across subjects, a higher variability was found in the muscle synergy vectors. Consequently, whatever the push-off index among the pole vaulters, the athletes used different muscle groupings (i.e., muscle synergy vectors) which were activated in a similar fashion (i.e., synergy activation coefficients). Overall, these results suggested that muscle coordination adopted between the time of straightened pole and the maximum height does not have a major influence on HP.
3D SURVEYING AND GEOMETRIC ASSESSMENT OF A GOTHIC NAVE VAULTING FROM POINT CLOUDS
Directory of Open Access Journals (Sweden)
A. Costa-Jover
2017-02-01
Full Text Available The development of massive data captures techniques (MDC in recent years, such as the Terrestrial laser Scanner (TLS, raises the possibility of developing new assessment procedures for architectural heritage. The 3D models that it is able to obtain is a great potential tool, both for conservation purposes and for historical and architectural studies. The paper proposes a simple, non-invasive methodology for the assessment of masonry vaults from point clouds which makes it possible to obtain relevant data about the formal anomalies. The methodology is tested in Tortosa’s Gothic Cathedral’s vaults, where the geometrical differences between vaults, a priori equal, are identified and related with the partially known construction phases. The procedure can be easily used on any other vaulted construction of any kind, but is especially useful to deal with the complex geometry of Gothic masonry vaults.
D Surveying and Geometric Assessment of a Gothic Nave Vaulting from Point Clouds
Costa-Jover, A.; Ginovart, J. Lluis i.; Coll-Pla, S.; López Piquer, M.; Samper-Sosa, A.; Moreno García, D.; Solís Lorenzo, A. M.
2017-02-01
The development of massive data captures techniques (MDC) in recent years, such as the Terrestrial laser Scanner (TLS), raises the possibility of developing new assessment procedures for architectural heritage. The 3D models that it is able to obtain is a great potential tool, both for conservation purposes and for historical and architectural studies. The paper proposes a simple, non-invasive methodology for the assessment of masonry vaults from point clouds which makes it possible to obtain relevant data about the formal anomalies. The methodology is tested in Tortosa's Gothic Cathedral's vaults, where the geometrical differences between vaults, a priori equal, are identified and related with the partially known construction phases. The procedure can be easily used on any other vaulted construction of any kind, but is especially useful to deal with the complex geometry of Gothic masonry vaults.
Cylindrically Polarized Nondiffracting Optical Pulses
Ornigotti, Marco; Szameit, Alexander
2016-01-01
We extend the concept of radially and azimuthally polarized optical beams to the polychromatic domain by introducing cylindrically polarized nondiffracting optical pulses. In particular, we discuss in detail the case of cylindrically polarized X-waves, both in the paraxial and nonparaxial regime. The explicit expressions for the electric and magnetic fields of cylindrically polarized X-waves is also reported.
Vault Nanoparticles Packaged with Enzymes as an Efficient Pollutant Biodegradation Technology.
Wang, Meng; Abad, Danny; Kickhoefer, Valerie A; Rome, Leonard H; Mahendra, Shaily
2015-11-24
Vault nanoparticles packaged with enzymes were synthesized as agents for efficiently degrading environmental contaminants. Enzymatic biodegradation is an attractive technology for in situ cleanup of contaminated environments because enzyme-catalyzed reactions are not constrained by nutrient requirements for microbial growth and often have higher biodegradation rates. However, the limited stability of extracellular enzymes remains a major challenge for practical applications. Encapsulation is a recognized method to enhance enzymatic stability, but it can increase substrate diffusion resistance, lower catalytic rates, and increase the apparent half-saturation constants. Here, we report an effective approach for boosting enzymatic stability by single-step packaging into vault nanoparticles. With hollow core structures, assembled vault nanoparticles can simultaneously contain multiple enzymes. Manganese peroxidase (MnP), which is widely used in biodegradation of organic contaminants, was chosen as a model enzyme in the present study. MnP was incorporated into vaults via fusion to a packaging domain called INT, which strongly interacts with vaults' interior surface. MnP fused to INT and vaults packaged with the MnP-INT fusion protein maintained peroxidase activity. Furthermore, MnP-INT packaged in vaults displayed stability significantly higher than that of free MnP-INT, with slightly increased Km value. Additionally, vault-packaged MnP-INT exhibited 3 times higher phenol biodegradation in 24 h than did unpackaged MnP-INT. These results indicate that the packaging of MnP enzymes in vault nanoparticles extends their stability without compromising catalytic activity. This research will serve as the foundation for the development of efficient and sustainable vault-based bioremediation approaches for removing multiple contaminants from drinking water and groundwater.
Rotating cylindrically symmetric Kaluza-Klein ﬂuid model
Indian Academy of Sciences (India)
Ramesh Tikekar; L K Patel
2000-09-01
Kaluza-Klein ﬁeld equations for stationary cylindrically symmetric ﬂuid models in standard Einstein theory are formulated and a set of physically viable solutions is reported. This set is believed to be the ﬁrst such Kaluza-Klein solutions and it includes the Kaluza-Klein counterpart of Davidson’s solution describing spacetime of a perfect ﬂuid in rigid rotation about a regular axis.
Pulling rigid bodies through granular material
Kubik, Ryan; Dressaire, Emilie
2016-11-01
The need for anchoring systems in granular materials such as sand is present in the marine transportation industry, e.g. to layout moorings, keep vessels and docks fixed in bodies of water, build oil rigs, etc. The holding power of an anchor is associated with the force exerted by the granular media. Empirical evidence indicates that the holding power depends on the size and shape of the anchoring structure. In this model study, we use a two-dimensional geometry in which a rigid body is pulled through a granular media at constant velocity to determine the drag and lift forces exerted by a granular medium on a moving object. The method allows measuring the drag force and recording the trajectory of the rigid object through the sand. We systematically vary the size and geometry of the rigid body, the properties of the granular medium and the extraction speed. For different initial positions of a cylindrical object pulled horizontally through the medium, we record large variations in magnitude of the drag and a significant lift force that pulls the object out of the sand.
Weiss, Asia; Whiteley, Walter
2014-01-01
This book contains recent contributions to the fields of rigidity and symmetry with two primary focuses: to present the mathematically rigorous treatment of rigidity of structures, and to explore the interaction of geometry, algebra, and combinatorics. Overall, the book shows how researchers from diverse backgrounds explore connections among the various discrete structures with symmetry as the unifying theme. Contributions present recent trends and advances in discrete geometry, particularly in the theory of polytopes. The rapid development of abstract polytope theory has resulted in a rich theory featuring an attractive interplay of methods and tools from discrete geometry, group theory, classical geometry, hyperbolic geometry and topology. The volume will also be a valuable source as an introduction to the ideas of both combinatorial and geometric rigidity theory and its applications, incorporating the surprising impact of symmetry. It will appeal to students at both the advanced undergraduate and gradu...
Pal, Tanmoy; Bhattacharjee, Somendra M.
2016-05-01
The temperature dependence of DNA flexibility is studied in the presence of stretching and unzipping forces. Two classes of models are considered. In one case the origin of elasticity is entropic due to the polymeric correlations, and in the other the double-stranded DNA is taken to have an intrinsic rigidity for bending. In both cases single strands are completely flexible. The change in the elastic constant for the flexible case due to thermally generated bubbles is obtained exactly. For the case of intrinsic rigidity, the elastic constant is found to be proportional to the square root of the bubble number fluctuation.
DEFF Research Database (Denmark)
Troiano, Giovanni Maria
Deformable and shape-changing interfaces are rapidly emerging in the field of human-computer interaction (HCI). Deformable interfaces provide users with newer input possibilities such as bending, squeezing, or stretching, which were impossible to achieve with rigid interfaces. Shape-changing inte......Deformable and shape-changing interfaces are rapidly emerging in the field of human-computer interaction (HCI). Deformable interfaces provide users with newer input possibilities such as bending, squeezing, or stretching, which were impossible to achieve with rigid interfaces. Shape...
Potentials of Mean Force Between Rigid Solvated Polymers
Energy Technology Data Exchange (ETDEWEB)
FRINK, LAURA J.D.; SALINGER, ANDREW G.
1999-09-29
In this letter we discusses the first application of 3-dimensional nonlocal density functional calculations to the interactions of solvated rigid polymers. The three cases considered are cylindrical polymers, bead-chain polymers, and periodic polymers. We calculate potentials of mean force, and show that polymer surface structure plays a critical role in determining the solvation energy landscape which in turn controls routes to assembly of the macromolecules.
The Acoustics of the Double Elliptical Vault of the Royal Palace of Caserta (Italy
Directory of Open Access Journals (Sweden)
Umberto Berardi
2017-03-01
Full Text Available This work investigates the acoustic characteristics of the double elliptical vault, which overlooks the Grand Staircase of the Royal Palace of Caserta (Italy. The Royal Palace was built by the architect Luigi Vanvitelli in the Seventeenth Century and it is the largest royal building in Italy. The double elliptical vault presents a great scenography effect. Inside the vault, on the planking level, musicians used to play for the king and his guests when the royal procession, going up the grand staircase, entered the royal apartments, creating astonishment among the guests who heard the music without understanding from where it was coming. Since the musicians were inside the vault, the long reverberation made the listeners perceive the vault to be enveloped by the music. To investigate this effect, the acoustic characteristics of the double vault were measured, putting the sound source on the planking level of the vault, while the microphones were put along the staircase and in the vestibule towards the royal apartments. Finally, the spatial distribution of several acoustic parameters is evaluated also using architectural acoustic simulations.
Composite analysis E-area vaults and saltstone disposal facilities
Energy Technology Data Exchange (ETDEWEB)
Cook, J.R.
1997-09-01
This report documents the Composite Analysis (CA) performed on the two active Savannah River Site (SRS) low-level radioactive waste (LLW) disposal facilities. The facilities are the Z-Area Saltstone Disposal Facility and the E-Area Vaults (EAV) Disposal Facility. The analysis calculated potential releases to the environment from all sources of residual radioactive material expected to remain in the General Separations Area (GSA). The GSA is the central part of SRS and contains all of the waste disposal facilities, chemical separations facilities and associated high-level waste storage facilities as well as numerous other sources of radioactive material. The analysis considered 114 potential sources of radioactive material containing 115 radionuclides. The results of the CA clearly indicate that continued disposal of low-level waste in the saltstone and EAV facilities, consistent with their respective radiological performance assessments, will have no adverse impact on future members of the public.
Directory of Open Access Journals (Sweden)
Wim Kamerling
2016-03-01
Full Text Available Just after World-War II building materials were scarce, architects and engineers had to design buildings using not much cement and steel. In French an architect, Jacques Couëlle, had invented a system with céramique infill elements to reduce for structures of concrete the self-weight and need of cement and steel. In the fifties and sixties of the twentieth century these céramique elements, known as Fusée Céramique elements, were used widely in France, North Africa and the Netherlands, mostly for barrel vaults and shells. Nowadays most of these structures are pulled down and the remaining buildings do not meet the demands of the present concerning climate comfort, insulation and safety.This thesis analyses the structural design of cylindrical Fusée Céramique roofs in the context of those days. The effect of the céramique infill elements for the time dependent deformations, stiffness and load bearing capacity, including second order, is studied. To save the few remaining buildings for the coming generations the possibilities to strengthen these structures with slender light elements of steel are explored. The effect of the strengthening is described for a Fusée Céramique vault, designed and constructed in the past.Reinforced concrete is a widely used building material with many advantages. Unfortunately the production of both reinforcement and cement is quite energy intensive and causes the emission of greenhouse gasses as NO2, NO and CO2. Reducing the need of cement is a relative simple way to reduce the emission of these greenhouse gasses.In practice roofs are seldom really flat but curved or at least slightly inclined, to drain rainwater and snow. Structurally curved structures, transferring loads as a surface-active or form-active structural system, are very efficient. The need of material and the self-weight is pretty low. This can be very useful if in the future the potentials of roofs for producing food and energy are used more
Sensor concentrator unit for the Continuous Automated Vault Inventory System
Energy Technology Data Exchange (ETDEWEB)
Nodine, R.N.; Lenarduzzi, R.
1997-06-01
The purpose of this document is to describe the use and operation of the sensor concentrator in the Continuous Automated Vault Inventory System (CAVIS). The CAVIS electronically verifies the presence of items of stored special nuclear material (SNM). US Department of Energy orders require that stored SNM be inventoried periodically to provide assurance that the material is secure. Currently this inventory is a highly manual activity, requiring personnel to enter the storage vaults. Using a CAVIS allows the frequency of physical inventories to be significantly reduced, resulting in substantial cost savings, increased security, and improved safety. The electronic inventory of stored SNM requires two different types of sensors for each item. The two sensors measure different parameters of the item, usually weight and gamma rays. A CAVIS is constructed using four basic system components: sensors, sensor concentrators, a data collection unit, and a database/user interface unit. One sensor concentrator supports the inventory of up to 20 items (40 sensors) and continuously takes readings from the item sensors. On request the sensor concentrator outputs the most recent sensor readings to the data collection unit. The information transfer takes place over a RS485 communications link. The data collection unit supports from 1 to 120 sensor concentrators (1 to 2,400 items) and is referred to as the Sensor Polling and Configuration System (SPCS). The SPCS is connected by a secure Transmission Control Protocol/Internet Protocol (TCP/IP) network to the database/user interface unit, which is referred to as the Graphical Facility Information Center (GraFIC). A CAVIS containing more than 2,400 items is supported by connecting additional SPCS units to the GraFIC.
Comparative Tests Between Shallow Downhole Installation and Classical Seismic Vaults
Charade, Olivier; Vergne, Jérôme; Bonaimé, Sébastien; Bonnin, Mickaël; Louis-Xavier, Thierry; Beucler, Eric; Manhaval, Bertrand; Arnold, Benoît
2016-04-01
The French permanent broadband network is engaged in a major evolution with the installation of a hundred of new stations within the forthcoming years. Since most of them will be located in open field environments, we are looking for a standardized installation method able to provide good noise level performance at a reasonable cost. Nowadays, the use of posthole seismometers that can be deployed at the bottom of shallow boreholes appears to be an affordable and alternative solution to more traditional installation methods such as seismic vaults or dedicated underground cellars. Here we present some comparative tests performed at different sites (including two GEOSCOPE stations), spanning various geological conditions. On each site, posthole sensors were deployed for several weeks to months at various depths from 1.5m up to 20m. We compare the seismic noise levels measured in the different boreholes with the one for a reference sensor either directly buried or installed in a tunnel, a cellar or a seismic vault. Apart from the microseism frequency band, seismic noise level in most of the boreholes equals or outperforms the one obtained for the reference sensors. At periods higher than 20s we observe a strong reduction of the seismic noise on the horizontal components in the deepest boreholes compared to near surface installations. This improvement can reach up to 30dB and appears to be mostly due to a reduction in tilt noise induced by wind or local pressure variations. However, the absolute noise level that can be achieved strongly depends on the local geology.
Sensor concentrator unit for the Continuous Automated Vault Inventory System
Energy Technology Data Exchange (ETDEWEB)
Nodine, R.N.; Lenarduzzi, R.
1997-06-01
The purpose of this document is to describe the use and operation of the sensor concentrator in the Continuous Automated Vault Inventory System (CAVIS). The CAVIS electronically verifies the presence of items of stored special nuclear material (SNM). US Department of Energy orders require that stored SNM be inventoried periodically to provide assurance that the material is secure. Currently this inventory is a highly manual activity, requiring personnel to enter the storage vaults. Using a CAVIS allows the frequency of physical inventories to be significantly reduced, resulting in substantial cost savings, increased security, and improved safety. The electronic inventory of stored SNM requires two different types of sensors for each item. The two sensors measure different parameters of the item, usually weight and gamma rays. A CAVIS is constructed using four basic system components: sensors, sensor concentrators, a data collection unit, and a database/user interface unit. One sensor concentrator supports the inventory of up to 20 items (40 sensors) and continuously takes readings from the item sensors. On request the sensor concentrator outputs the most recent sensor readings to the data collection unit. The information transfer takes place over a RS485 communications link. The data collection unit supports from 1 to 120 sensor concentrators (1 to 2,400 items) and is referred to as the Sensor Polling and Configuration System (SPCS). The SPCS is connected by a secure Transmission Control Protocol/Internet Protocol (TCP/IP) network to the database/user interface unit, which is referred to as the Graphical Facility Information Center (GraFIC). A CAVIS containing more than 2,400 items is supported by connecting additional SPCS units to the GraFIC.
Energy Technology Data Exchange (ETDEWEB)
Meson, Alejandro M., E-mail: meson@iflysib.unlp.edu.ar; Vericat, Fernando, E-mail: vericat@iflysib.unlp.edu.ar [CONICET-UNLP, Instituto de Fisica de Liquidos y Sistemas Biologicos (IFLYSIB) (Argentina)
2011-12-15
We analyze when a multifractal spectrum can be used to recover the potential. This phenomenon is known as multifractal rigidity. We prove that for a certain class of potentials the multifractal spectrum of local entropies uniquely determines their equilibrium states. This leads to a classification which identifies two systems up to a change of variables.
Electrostatics of Rigid Polyelectrolytes
Energy Technology Data Exchange (ETDEWEB)
Wong, G.C.L.
2009-06-04
The organization of rigid biological polyelectrolytes by multivalent ions and macroions are important for many fundamental problems in biology and biomedicine, such as cytoskeletal regulation and antimicrobial sequestration in cystic fibrosis. These polyelectrolytes have been used as model systems for understanding electrostatics in complex fluids. Here, we review some recent results in theory, simulations, and experiments.
Electoral Stability and Rigidity
Levy, Michael Y
2016-01-01
Some argue that political stability is best served through a two-party system. This study refutes this. The author mathematically defines the stability and rigidity of electoral systems comprised of any quantity of electors and parties. In fact, stability is a function of the quantity of electors - i.e., the number of occupied seats at the table. As the number of electors increases, the properties of an electorate are increasingly well resolved, and well described by those of an electorate that is least excessive -- that is to say an electorate that is closest to equilibrium. Further, electoral rigidity is a function of the quantity of parties and their probabilities of representation. An absolutely rigid system admits no fluctuations -- whatever happens to one elector will happen to all electors. As the quantity of parties increases so does the number of party lines, and with it the quantity of alternatives with which to respond to an external stimulus. Rigidity is significant in a social system that places ...
Indentation of Ellipsoidal and Cylindrical Elastic Shells
Vella, Dominic
2012-10-01
Thin shells are found in nature at scales ranging from viruses to hens\\' eggs; the stiffness of such shells is essential for their function. We present the results of numerical simulations and theoretical analyses for the indentation of ellipsoidal and cylindrical elastic shells, considering both pressurized and unpressurized shells. We provide a theoretical foundation for the experimental findings of Lazarus etal. [following paper, Phys. Rev. Lett. 109, 144301 (2012)PRLTAO0031-9007] and for previous work inferring the turgor pressure of bacteria from measurements of their indentation stiffness; we also identify a new regime at large indentation. We show that the indentation stiffness of convex shells is dominated by either the mean or Gaussian curvature of the shell depending on the pressurization and indentation depth. Our results reveal how geometry rules the rigidity of shells. © 2012 American Physical Society.
Directory of Open Access Journals (Sweden)
Kemal Idrizović
2006-06-01
Full Text Available Complexity of requirements posed by the physical education instruction, especially with regard to programme of exercises on gymnastic apparatuses, can be noticed very well in motoric structures such as vaults. Vaults applied in this research essentially mean fundamental motoric systems of such type and precisely because of this they are the subject of this work which, additionally to vaults, deals with ten motoric tests representing manifestations of explosive strength, repetitive strength, static strength, coordination and flexibility. The aim of this research is to determine the predictive value systemically, as well as separately for each motoric test in relation to two criterion variables separately
Behavior of R/C Cylindrical Panel Subjected to Combined Axial and Shear Loadings
Hara, Takashi
2009-01-01
p. 1722-1730 Reinforced concrete (R/C) cylindrical panels have been applied to the roof or the underground structures. Also, in constructing a high rise building, an R/C wall is often used to improve the lateral rigidity of the building comparing with beam column systems under wind or seismic loading. In this paper, the behavior of R/C cylindrical shell under combined axial and lateral shear loadings is analyzed numerically. R/C cylindrical shells are often adopted for the core wa...
Cup Cylindrical Waveguide Antenna
Acosta, Roberto J.; Darby, William G.; Kory, Carol L.; Lambert, Kevin M.; Breen, Daniel P.
2008-01-01
The cup cylindrical waveguide antenna (CCWA) is a short backfire microwave antenna capable of simultaneously supporting the transmission or reception of two distinct signals having opposite circular polarizations. Short backfire antennas are widely used in mobile/satellite communications, tracking, telemetry, and wireless local area networks because of their compactness and excellent radiation characteristics. A typical prior short backfire antenna contains a half-wavelength dipole excitation element for linear polarization or crossed half-wavelength dipole elements for circular polarization. In order to achieve simultaneous dual circular polarization, it would be necessary to integrate, into the antenna feed structure, a network of hybrid components, which would introduce significant losses. The CCWA embodies an alternate approach that entails relatively low losses and affords the additional advantage of compactness. The CCWA includes a circular cylindrical cup, a circular disk subreflector, and a circular waveguide that serves as the excitation element. The components that make it possible to obtain simultaneous dual circular polarization are integrated into the circular waveguide. These components are a sixpost polarizer and an orthomode transducer (OMT) with two orthogonal coaxial ports. The overall length of the OMT and polarizer (for the nominal middle design frequency of 2.25 GHz) is about 11 in. (approximately equal to 28 cm), whereas the length of a commercially available OMT and polarizer for the same frequency is about 32 in. (approximately equal to 81 cm).
Obituary--rigid contact lenses.
Efron, Nathan
2010-10-01
Scleral and corneal rigid lenses represented 100 per cent of the contact lens market immediately prior to the invention of soft lenses in the mid-1960s. In the United Kingdom today, rigid lenses comprise 2 per cent of all new lens fits. Low rates of rigid lens fitting are also apparent in 27 other countries which have recently been surveyed. Thus, the 1998 prediction of the author that rigid lenses--also referred to as 'rigid gas permeable' (RGP) lenses or 'gas permeable' (GP) lenses--would be obsolete by the year 2010 has essentially turned out to be correct. In this obituary, the author offers 10 reasons for the demise of rigid lens fitting: initial rigid lens discomfort; intractable rigid lens-induced corneal and lid pathology; extensive soft lens advertising; superior soft lens fitting logistics; lack of rigid lens training opportunities; redundancy of the rigid lens 'problem solver' function; improved soft toric and bifocal/varifocal lenses; limited uptake of orthokeratology; lack of investment in rigid lenses; and the emergence of aberration control soft lenses. Rigid lenses are now being fitted by a minority of practitioners with specialist skills/training. Certainly, rigid lenses can no longer be considered as a mainstream form of contact lens correction. May their dear souls (bulk properties) rest in peace.
Orientation of cylindrical particles in gas-solid circulating fluidized bed
Institute of Scientific and Technical Information of China (English)
Jie Cai; Qihe Li; Zhulin Yuan
2012-01-01
The orientation of cylindrical particles in a gas-solid circulating fluidized bed was investigated by establishing a three-dimensional Euler-Lagrange model on the basis of rigid kinetics,impact kinetics and gas-solid two-phase flow theory.The resulting simulation indicated that the model could well illustrate the orientation of cylindrical particles in a riser during fluidization,The influences of bed structure and operation parameters on orientation of cylindrical particles were then studied and compared with related experimental results.The simulation results showed that the majority of cylindrical particles move with small nutation angles in the riser,the orientation of cylindrical particles is affected more obviously by their positions than by their slenderness and local gas velocities.The simulation results well agree with experiments,thus validating the proposed model and computation.
Motion parallax in immersive cylindrical display systems
Filliard, N.; Reymond, G.; Kemeny, A.; Berthoz, A.
2012-03-01
Motion parallax is a crucial visual cue produced by translations of the observer for the perception of depth and selfmotion. Therefore, tracking the observer viewpoint has become inevitable in immersive virtual (VR) reality systems (cylindrical screens, CAVE, head mounted displays) used e.g. in automotive industry (style reviews, architecture design, ergonomics studies) or in scientific studies of visual perception. The perception of a stable and rigid world requires that this visual cue be coherent with other extra-retinal (e.g. vestibular, kinesthetic) cues signaling ego-motion. Although world stability is never questioned in real world, rendering head coupled viewpoint in VR can lead to the perception of an illusory perception of unstable environments, unless a non-unity scale factor is applied on recorded head movements. Besides, cylindrical screens are usually used with static observers due to image distortions when rendering image for viewpoints different from a sweet spot. We developed a technique to compensate in real-time these non-linear visual distortions, in an industrial VR setup, based on a cylindrical screen projection system. Additionally, to evaluate the amount of discrepancies tolerated without perceptual distortions between visual and extraretinal cues, a "motion parallax gain" between the velocity of the observer's head and that of the virtual camera was introduced in this system. The influence of this artificial gain was measured on the gait stability of free-standing participants. Results indicate that, below unity, gains significantly alter postural control. Conversely, the influence of higher gains remains limited, suggesting a certain tolerance of observers to these conditions. Parallax gain amplification is therefore proposed as a possible solution to provide a wider exploration of space to users of immersive virtual reality systems.
Addendum to the composite analysis for the E-Area Vaults and Saltstone Disposal Facilities
Energy Technology Data Exchange (ETDEWEB)
Cook, J.R.
2000-03-13
This report documents the composite analysis performed on the two active SRS low-level radioactive waste disposal facilities. The facilities are the Z-Area Saltstone Disposal Facility and the E-Area Vaults Disposal Facility.
A lime based mortar for thermal insulation of medieval church vaults
DEFF Research Database (Denmark)
Hansen, Tessa Kvist; Larsen, Poul Klenz; Hansen, Kurt Kielsgaard
There are 1700 medieval churches in Denmark, and many of these have brick vaults. The thickness is only 12 – 15 cm, and the heat loss through this building component is large. Thermal insulation has not been permitted until now in respect for the antiquarian values and doubts about the effect...... on water vapour transport through the vault, and the risk of condensation inside the insulation. A new mortar was developed for thermal insulation of bricks vaults, consisting mainly of expanded perlite, mixed with slaked lime. These materials are compatible with the fired clay bricks and the lime mortar...... joints. The insulation mortar is applied to the top side of the vault in a thickness of 10 cm, and covered by 10 mm lime plaster, reinforced with cattle hair. This assembly is resistant to the weight of a person, working with maintenance of the roof. The thermal conductivity of the insulation mortar...
Directory of Open Access Journals (Sweden)
Soo-Jeong Lee
2017-05-01
Conclusion: Vaginal vault drainage could be a safe alternative that allows for the management of postoperative morbidity and retains the advantages of minimally invasive surgery after complicated SPA-LAVH.
He, Chenxu; Wylie, William
2011-01-01
In this paper we study the space of solutions to an overdetermined linear system involving the Hessian of functions. We show that if the solution space has dimension greater than one, then the underlying manifold has a very rigid warped product structure. This warped product structure will be used to study warped product Einstein structures in our paper "The space of virtual solutions to the warped product Einstein equation".
Analysis of Risk Factors for Post-Hysterectomy Vaginal Vault Prolapse
Directory of Open Access Journals (Sweden)
Mahmut Kuntay kuntay Kokanali
2015-03-01
Conclusions: Vault prolapse after hysterectomy is a relatively rare complication. Elderly age, obesity, chronic obstructive lung diseases, prior genital prolapse sugery, vaginal hysterectomy, genital prolapse as indication of hysterectomy and the number of vaginal delivery and #8805;2 increase vault prolapse risk. Identification of these risk factors is important to prevent this complication. [Cukurova Med J 2015; 40(1.000: 63-71
The Application of Carbon Composites in the Rehabilitation of Historic Baroque Vaults
Directory of Open Access Journals (Sweden)
Jiří Witzany
2015-12-01
Full Text Available The stabilization and reinforcement of damaged barrel vaults with lunettes over an arcaded walk, applying composite strips based on high-strength carbon fibers and epoxy resin, was performed during the restoration of a historic monastery. The application of reinforcing composite strips in the soffit of damaged barrel vaults was preceded by relatively extensive experimental research and theoretical analyses. This method significantly reduces the interventions into and the degradation of the original historic structure (surface application and is reversible.
Cylindrical geometry hall thruster
Raitses, Yevgeny; Fisch, Nathaniel J.
2002-01-01
An apparatus and method for thrusting plasma, utilizing a Hall thruster with a cylindrical geometry, wherein ions are accelerated in substantially the axial direction. The apparatus is suitable for operation at low power. It employs small size thruster components, including a ceramic channel, with the center pole piece of the conventional annular design thruster eliminated or greatly reduced. Efficient operation is accomplished through magnetic fields with a substantial radial component. The propellant gas is ionized at an optimal location in the thruster. A further improvement is accomplished by segmented electrodes, which produce localized voltage drops within the thruster at optimally prescribed locations. The apparatus differs from a conventional Hall thruster, which has an annular geometry, not well suited to scaling to small size, because the small size for an annular design has a great deal of surface area relative to the volume.
A COMPARISON OF UPPER-EXTREMITY REACTION FORCES BETWEEN THE YURCHENKO VAULT AND FLOOR EXERCISE
Directory of Open Access Journals (Sweden)
Matthew Kirk Seeley
2005-06-01
Full Text Available The purpose of this study was to examine reaction forces transmitted to the upper extremities of high-level gymnasts during the round-off phase of the Yurchenko vault. A secondary purpose of this study was to compare reaction forces during the Yurchenko vault to reaction forces observed in a tumbling pass during the floor exercise. Ten high-level, female gymnasts volunteered to participate. Conditions of the independent variable were the Yurchenko vault and floor exercise; dependent variables were peak vertical and peak anterior-posterior reaction forces. Each participant performed three trials of both conditions with the trail hand contacting a force platform. Vertical and anterior-posterior reaction forces, normalized to body weight, were greater (p < 0.05 during the round-off phase of the Yurchenko vault (2.38 than during the floor exercise round-off (2.15. Vertical reaction forces during the round-off phase of the Yurchenko vault and floor exercise round-off are similar to reaction forces transmitted to upper extremities during other gymnastic skills and ground reaction forces transmitted to lower extremities while running and walking at various speeds. Results of this study reveal a need for further research considering methods aimed at reducing reaction forces transmitted to the upper extremities during the Yurchenko vault and floor exercise.
Searchable Data Vault: Encrypted Queries in Secure Distributed Cloud Storage
Directory of Open Access Journals (Sweden)
Geong Sen Poh
2017-05-01
Full Text Available Cloud storage services allow users to efficiently outsource their documents anytime and anywhere. Such convenience, however, leads to privacy concerns. While storage providers may not read users’ documents, attackers may possibly gain access by exploiting vulnerabilities in the storage system. Documents may also be leaked by curious administrators. A simple solution is for the user to encrypt all documents before submitting them. This method, however, makes it impossible to efficiently search for documents as they are all encrypted. To resolve this problem, we propose a multi-server searchable symmetric encryption (SSE scheme and construct a system called the searchable data vault (SDV. A unique feature of the scheme is that it allows an encrypted document to be divided into blocks and distributed to different storage servers so that no single storage provider has a complete document. By incorporating the scheme, the SDV protects the privacy of documents while allowing for efficient private queries. It utilizes a web interface and a controller that manages user credentials, query indexes and submission of encrypted documents to cloud storage services. It is also the first system that enables a user to simultaneously outsource and privately query documents from a few cloud storage services. Our preliminary performance evaluation shows that this feature introduces acceptable computation overheads when compared to submitting documents directly to a cloud storage service.
Energy Technology Data Exchange (ETDEWEB)
Barnett, J.M.
1998-03-25
The Hanford Site, located adjacent to and north of Richland, Washington, is operated by the US Department of Energy, Richland Operations Office (RL). The 324 Building is located in the 300 Area of the Hanford Site. The 324 Building was constructed in the 1960s to support materials and chemical process research and development activities ranging from laboratory/bench-scale studies to full engineering-scale pilot plant demonstrations. In the mid-1990s, it was determined that dangerous waste and waste residues were being stored for greater than 90 days in the 324 Building Radiochemical Engineering Cells (REC) and in the High-Level Vault/Low-Level Vault (HLV/LLV) tanks. [These areas are not Resource Conservation and Recovery Act of 1976 (RCRA) permitted portions of the 324 Building.] Through the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) Milestone M-89, agreement was reached to close the nonpermitted RCRA unit in the 324 Building. This closure plan, managed under TPA Milestone M-20-55, addresses the identified building areas targeted by the Tri-Party Agreement and provides commitments to achieve the highest degree of compliance practicable, given the special technical difficulties of managing mixed waste that contains high-activity radioactive materials, and the physical limitations of working remotely in the areas within the subject closure unit. This closure plan is divided into nine chapters. Chapter 1.0 provides the introduction, historical perspective, 324 Building history and current mission, and the regulatory basis and strategy for managing the closure unit. Chapters 2.0, 3.0, 4.0, and 5.0 discuss the detailed facility description, process information, waste characteristics, and groundwater monitoring respectively. Chapter 6.0 deals with the closure strategy and performance standard, including the closure activities for the B-Cell, D-Cell, HLV, LLV; piping and miscellaneous associated building areas. Chapter 7.0 addresses the
Energy Technology Data Exchange (ETDEWEB)
Barnett, J.M.
1998-03-25
The Hanford Site, located adjacent to and north of Richland, Washington, is operated by the US Department of Energy, Richland Operations Office (RL). The 324 Building is located in the 300 Area of the Hanford Site. The 324 Building was constructed in the 1960s to support materials and chemical process research and development activities ranging from laboratory/bench-scale studies to full engineering-scale pilot plant demonstrations. In the mid-1990s, it was determined that dangerous waste and waste residues were being stored for greater than 90 days in the 324 Building Radiochemical Engineering Cells (REC) and in the High-Level Vault/Low-Level Vault (HLV/LLV) tanks. [These areas are not Resource Conservation and Recovery Act of 1976 (RCRA) permitted portions of the 324 Building.] Through the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) Milestone M-89, agreement was reached to close the nonpermitted RCRA unit in the 324 Building. This closure plan, managed under TPA Milestone M-20-55, addresses the identified building areas targeted by the Tri-Party Agreement and provides commitments to achieve the highest degree of compliance practicable, given the special technical difficulties of managing mixed waste that contains high-activity radioactive materials, and the physical limitations of working remotely in the areas within the subject closure unit. This closure plan is divided into nine chapters. Chapter 1.0 provides the introduction, historical perspective, 324 Building history and current mission, and the regulatory basis and strategy for managing the closure unit. Chapters 2.0, 3.0, 4.0, and 5.0 discuss the detailed facility description, process information, waste characteristics, and groundwater monitoring respectively. Chapter 6.0 deals with the closure strategy and performance standard, including the closure activities for the B-Cell, D-Cell, HLV, LLV; piping and miscellaneous associated building areas. Chapter 7.0 addresses the
Cylindrically symmetric dust spacetime
Senovilla, J M M; Senovilla, Jose M. M.; Vera, Raul
2000-01-01
We present an explicit exact solution of Einstein's equations for an inhomogeneous dust universe with cylindrical symmetry. The spacetime is extremely simple but nonetheless it has new surprising features. The universe is ``closed'' in the sense that the dust expands from a big-bang singularity but recollapses to a big-crunch singularity. In fact, both singularities are connected so that the whole spacetime is ``enclosed'' within a single singularity of general character. The big-bang is not simultaneous for the dust, and in fact the age of the universe as measured by the dust particles depends on the spatial position, an effect due to the inhomogeneity, and their total lifetime has no non-zero lower limit. Part of the big-crunch singularity is naked. The metric depends on a parameter and contains flat spacetime as a non-singular particular case. For appropriate values of the parameter the spacetime is a small perturbation of Minkowski spacetime. This seems to indicate that flat spacetime may be unstable agai...
Cylindrically symmetric dust spacetime
Senovilla, José M. M.
2000-07-01
We present an explicit exact solution of Einstein's equations for an inhomogeneous dust universe with cylindrical symmetry. The spacetime is extremely simple but nonetheless it has surprising new features. The universe is `closed' in the sense that the dust expands from a big-bang singularity but recollapses to a big-crunch singularity. In fact, both singularities are connected so that the whole spacetime is `enclosed' within a single singularity of general character. The big-bang is not simultaneous for the dust, and in fact the age of the universe as measured by the dust particles depends on the spatial position, an effect due to the inhomogeneity, and their total lifetime has no non-zero lower limit. Part of the big-crunch singularity is naked. The metric depends on a parameter and contains flat spacetime as a non-singular particular case. For appropriate values of the parameter the spacetime is a small perturbation of Minkowski spacetime. This seems to indicate that flat spacetime may be unstable against some global non-vacuum perturbations.
Tanaka, Hideaki; Kato, Koji; Yamashita, Eiki
Vaults are among the largest cytoplasmic ribonucleoprotein particles and are found in numerous eukaryotic species. Although roles in multidrug resistance and innate immunity have been suggested, the cellular function remains unclear. We have determined the X-ray structure of rat liver vault at 3.5 Å resolution. A vault particle shell was composed of 78 MVP (Major vault protein) chains with 39-fold dihedral symmetry. The shoulder domain of MVP is structurally similar to SPFH (stomatin/prohibitin/flotillin/HflK/C) domain involved in lipid raft association.
Directory of Open Access Journals (Sweden)
Roberta Spallone
2012-06-01
Full Text Available Plantery's vaults, by the name of the architect working in Turin since first years of '700, are composed by a main vault intersected by some axial and angular secondary vaults. Plantery's vaults allow to roof over unitary spaces obtaining effects of lightness also by small rises. Their diffusion, up to the '80s of the century, in boardrooms as palaces halls, and the richness of variations on the theme, justifies a research, that makes use of survey and digital modeling. This research is focused on the relationships between geometric models and built architecture, connected by use of materials, construction techniques and decorative styles.
NONLINEAR FARADAY WAVES IN A PARAMETRICALLY EXCITED CIRCULAR CYLINDRICAL CONTAINER
Institute of Scientific and Technical Information of China (English)
菅永军; 鄂学全; 柏威
2003-01-01
In the cylindrical coordinate system, a singular perturbation theory of multiple-scale asymptotic expansions was developed to study single standing water wave mode bysolving potential equations of water waves in a rigid circular cylinder, which is subject to avertical oscillation. It is assumed that the fluid in the circular cylindrical vessel is inviscid ,incompressible and the motion is irrotational, a nonlinear amplitude equation with cubicand vertically excited terms of the vessel was derived by expansion of two-time scales withoutconsidering the effect of surface tension. It is shown by numerical computation that differentfree surface standing wave patterns will be formed in different excited frequencies andamplitudes. The contours of free surface waves are agreed well with the experimental resultswhich were carried out several years ago.
Torsional Rigidity of Minimal Submanifolds
DEFF Research Database (Denmark)
Markvorsen, Steen; Palmer, Vicente
2006-01-01
We prove explicit upper bounds for the torsional rigidity of extrinsic domains of minimal submanifolds $P^m$ in ambient Riemannian manifolds $N^n$ with a pole $p$. The upper bounds are given in terms of the torsional rigidities of corresponding Schwarz symmetrizations of the domains in warped...... for the torsional rigidity are actually attained and give conditions under which the geometric average of the stochastic mean exit time for Brownian motion at infinity is finite....
Jiang, Janina; Liu, Guangchao; Kickhoefer, Valerie A.; Rome, Leonard H.; Li, Lin-Xi; McSorley, Stephen J.; Kelly, Kathleen A.
2017-01-01
Chlamydia trachomatis genital infection is the most common sexually transmitted bacterial disease, causing a significant burden to females due to reproductive dysfunction. Intensive screening and antibiotic treatment are unable to completely prevent female reproductive dysfunction, thus, efforts have become focused on developing a vaccine. A major impediment is identifying a safe and effective adjuvant which induces cluster of differentiation 4 (CD4) cells with attributes capable of halting genital infection and inflammation. Previously, we described a natural nanocapsule called the vault which was engineered to contain major outer membrane protein (MOMP) and was an effective vaccine which significantly reduced early infection and favored development of a cellular immune response in a mouse model. In the current study, we used another chlamydial antigen, a polymorphic membrane protein G-1 (PmpG) peptide, to track antigen-specific cells and evaluate, in depth, the vault vaccine for its protective capacity in the absence of an added adjuvant. We found PmpG-vault immunized mice significantly reduced the genital bacterial burden and histopathologic parameters of inflammation following a C. muridarum challenge. Immunization boosted antigen-specific CD4 cells with a multiple cytokine secretion pattern and reduced the number of inflammatory cells in the genital tract making the vault vaccine platform safe and effective for chlamydial genital infection. We conclude that vaccination with a Chlamydia-vault vaccine boosts antigen-specific immunities that are effective at eradicating infection and preventing reproductive tract inflammation. PMID:28106821
Abe, Akiko; Matoda, Maki; Okamoto, Sanshiro; Kondo, Eiji; Kato, Kazuyoshi; Omatsu, Kohei; Umayahara, Kenji; Utsugi, Kuniko; Takeshima, Nobuhiro
2015-04-02
We describe our experiences with vaginal vault resection for vaginal recurrence of cervical cancer after hysterectomy and radiotherapy. After operative treatment, the rate of vaginal vault recurrence of uterine cervical cancer is reported to be about 5%. There is no consensus regarding the treatment for these cases. Between 2004 and 2012, eight patients with vaginal vault recurrence underwent removal of the vaginal wall via laparotomy after hysterectomy and radiotherapy. The median patient age was 45 years (range 35 to 70 years). The median operation time was 244.5 min (range 172 to 590 min), the median estimated blood loss was 362.5 mL (range 49 to 1,890 mL), and the median duration of hospitalization was 24.5 days (range 11 to 50 days). Two patients had intraoperative complications: a grade 1 bowel injury and a grade 1 bladder injury. The following postoperative complications were observed: one patient had vaginal vault bleeding, three patients developed vesicovaginal fistulae, and one patient had repeated ileus. Two patients needed clean intermittent catheterization. Local control was achieved in five of the eight cases. Vaginal vault resection is an effective treatment for vaginal recurrence of cervical cancer after hysterectomy and radiotherapy. However, complications of this procedure can be expected to reduce quality of life. Therefore, this operation should be selected with great care.
Rigid collapsible dish structure
Palmer, William B. (Inventor); Giebler, Martin M. (Inventor)
1982-01-01
A collapsible dish structure composed of a plurality of rows of rigid radial petal assemblies concentric with the axis of the dish. The petal assemblies consist of a center petal and two side petals, the center petal hinged on an axis tangent to a circle concentric with the axis of the dish and the side petals hinged to the center petal at their mating edge. The center petal is foldable inwardly and the side petals rotate about their hinges such that the collapsed dish structure occupies a much smaller volume than the deployed dish. Means of controlling the shape of the dish to compensate for differential expansion of the deployed dish are also provided.
McGrath, Paul L
2014-01-01
In this thesis, I examine in detail the properties of rigid quasilocal frames (RQF), which have been proposed as a geometrically natural way to define spatially extended reference frames in general relativity. I also explore their usefulness, in particular, as a tool for constructing completely general conservation laws that do not rely on the presence of spacetime symmetries and include both matter and gravitational contributions without the need for any ad hoc structures such as pseudotensors. In doing so, I show how the RQF approach affords a deeper understanding of the nature of gravitational fluxes via the equivalence principle. Finally, I apply the RQF formalism to explore Ehrenfest's rotating disk paradox, a generalization of Archimedes' law to curved spacetime, tidal interactions for Earth's and Jupiter's moons, and more.
DEFF Research Database (Denmark)
Troiano, Giovanni Maria
to convey particular information (e.g., big-isurgent, loud-is-up). The second work presents a large-scale analysis of 340 Sci-Fi movies that identifies instances of shape-changing interfaces. Results from the analysis reveals emergent behavioral patterns of shape change, namely Reconfiguration......Deformable and shape-changing interfaces are rapidly emerging in the field of human-computer interaction (HCI). Deformable interfaces provide users with newer input possibilities such as bending, squeezing, or stretching, which were impossible to achieve with rigid interfaces. Shape......-changing interfaces can reconfigure their shape dynamically, providing users with new affordances and output modalities. This thesis contributes to both the field of deformable interfaces and shape-changing interfaces through empirical research. In the area of deformable interfaces, this thesis presents two studies...
Design and construction of the tensioned ties for UX15 cavern vault
Parkin, R J H
2002-01-01
Due to the programme constraints for the UX15 cavern set by CERN, it has been necessary to complete the concrete lining of the vault prior to the excavation of the bench. The vault lining is therefore being temporarily suspended from a number of pre-tensioned high capacity multi-strand tensioned ties. During excavation of the bench, additional loads will be imposed onto the vault lining due to ground displacements. In order to minimise the number of ties, the previously completed linings of the PX14 and PX16 access shafts will be used to support some of the load. Three-dimensional modelling has been undertaken to design the structures and determine the expected behaviour of this complex support system. Geotechnical instrumentation has been installed in the concrete linings and the ground to monitor loads and displacements during construction. After the cavern walls have been completed, the ties will be released.
Vaginal vault recurrences of endometrial cancer in non-irradiated patients
DEFF Research Database (Denmark)
Hardarson, Hordur Alexander; Nyhøj Heidemann, Lene; Christensen, René dePont;
2015-01-01
are few and limited to previously irradiated patients or patients with advanced disease. Investigation of surgical treatment for isolated vaginal vault recurrence is practically nonexistent. The aim of this study is to evaluate the efficacy of RT and ST in a non-irradiated group with recurrent endometrial......BACKGROUND: The treatment of locally recurrent endometrial cancer is based on limited evidence. The standard treatment is radiotherapy (RT) which is effective for local control and the effect has been documented in prospective studies. Investigations of surgical treatment (ST) of recurrences...... cancer limited to the vaginal vault. METHODS: Patients treated for recurrent endometrial cancer at Odense University Hospital, Denmark between 2003 and 2012 were identified, n = 118. Thirty-three patients had an isolated vaginal vault recurrence and were treated with either RT, ST or both. Re...
Beyond BLASTing: tertiary and quaternary structure analysis helps identify major vault proteins.
Daly, Toni K; Sutherland-Smith, Andrew J; Penny, David
2013-01-01
We examine the advantages of going beyond sequence similarity and use both protein three-dimensional (3D) structure prediction and then quaternary structure (docking) of inferred 3D structures to help evaluate whether comparable sequences can fold into homologous structures with sufficient lateral associations for quaternary structure formation. Our test case is the major vault protein (MVP) that oligomerizes in multiple copies to form barrel-like vault particles and is relatively widespread among eukaryotes. We used the iterative threading assembly refinement server (I-TASSER) to predict whether putative MVP sequences identified by BLASTp and PSI Basic Local Alignment Search Tool are structurally similar to the experimentally determined rodent MVP tertiary structures. Then two identical predicted quaternary structures from I-TASSER are analyzed by RosettaDock to test whether a pair-wise association occurs, and hence whether the oligomeric vault complex is likely to form for a given MVP sequence. Positive controls for the method are the experimentally determined rat (Rattus norvegicus) vault X-ray crystal structure and the purple sea urchin (Strongylocentrotus purpuratus) MVP sequence that forms experimentally observed vaults. These and two kinetoplast MVP structural homologs were predicted with high confidence value, and RosettaDock predicted that these MVP sequences would dock laterally and therefore could form oligomeric vaults. As the negative control, I-TASSER did not predict an MVP-like structure from a randomized rat MVP sequence, even when constrained to the rat MVP crystal structure (PDB:2ZUO), thus further validating the method. The protocol identified six putative homologous MVP sequences in the heterobolosean Naegleria gruberi within the excavate kingdom. Two of these sequences are predicted to be structurally similar to rat MVP, despite being in excess of 300 residues shorter. The method can be used generally to help test predictions of homology via
Directory of Open Access Journals (Sweden)
M. Capone
2015-02-01
benefits and the troubles. From a methodological point of view this is our workflow: - theoretical study about geometrical configuration of rib vault systems; - 3D model based on theoretical hypothesis about geometric definition of the vaults' form; - 3D model based on image matching 3D reconstruction methods; - comparison between 3D theoretical model and 3D model based on image matching;
International rigid contact lens prescribing.
Efron, Nathan; Morgan, Philip B; Helland, Magne; Itoi, Motozumi; Jones, Deborah; Nichols, Jason J; van der Worp, Eef; Woods, Craig A
2010-06-01
Rigid lenses have been fitted less since the introduction of soft lenses nearly 40 years ago. Data that we have gathered from annual contact lens fitting surveys conducted in Australia, Canada, Japan, the Netherlands, Norway, the UK and the USA between 2000 and 2008 facilitate an accurate characterization of the pattern of the decline of rigid lens fitting during the first decade of this century. There is a trend for rigid lenses to be utilized primarily for refitting those patients who are already successful rigid lens wearers-most typically older females being refit with higher Dk materials. Rigid lenses are generally fitted on a full-time basis (four or more days of wear per week) without a planned replacement schedule. Orthokeratology is especially popular in the Netherlands, but is seldom prescribed in the other countries surveyed.
LoPresti, Melissa; Daniels, Bradley; Buchanan, Edward P; Monson, Laura; Lam, Sandi
2017-04-01
Repeat surgery for restenosis after initial nonsyndromic craniosynostosis intervention is sometimes needed. Calvarial vault reconstruction through a healed surgical bed adds a level of intraoperative complexity and may benefit from preoperative and intraoperative definitions of biometric and aesthetic norms. Computer-assisted design and manufacturing using 3D imaging allows the precise formulation of operative plans in anticipation of surgical intervention. 3D printing turns virtual plans into anatomical replicas, templates, or customized implants by using a variety of materials. The authors present a technical note illustrating the use of this technology: a repeat calvarial vault reconstruction that was planned and executed using computer-assisted design and 3D printed intraoperative guides.
Quantum charged rigid membrane
Energy Technology Data Exchange (ETDEWEB)
Cordero, Ruben [Departamento de Fisica, Escuela Superior de Fisica y Matematicas del I.P.N., Unidad Adolfo Lopez Mateos, Edificio 9, 07738 Mexico, D.F. (Mexico); Molgado, Alberto [Unidad Academica de Fisica, Universidad Autonoma de Zacatecas, Zacatecas Zac. (Mexico); Rojas, Efrain, E-mail: cordero@esfm.ipn.mx, E-mail: amolgado@fisica.uaz.edu.mx, E-mail: efrojas@uv.mx [Departamento de Fisica, Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico)
2011-03-21
The early Dirac proposal to model the electron as a charged membrane is reviewed. A rigidity term, instead of the natural membrane tension, involving linearly the extrinsic curvature of the worldvolume swept out by the membrane is considered in the action modeling the bubble in the presence of an electromagnetic field. We set up this model as a genuine second-order derivative theory by considering a non-trivial boundary term which plays a relevant part in our formulation. The Lagrangian in question is linear in the bubble acceleration and by means of the Ostrogradski-Hamiltonian approach, we observed that the theory comprises the management of both first- and second-class constraints. We thus show that our second-order approach is robust allowing for a proper quantization. We found an effective quantum potential which permits us to compute bounded states for the system. We comment on the possibility of describing brane world universes by invoking this kind of second-order correction terms.
Quantum charged rigid membrane
Cordero, Ruben; Rojas, Efrain
2010-01-01
The early Dirac proposal to model the electron as a charged membrane is reviewed. A rigidity term, instead of the natural membrane tension, involving linearly the extrinsic curvature of the worldvolume swept out by the membrane is considered in the action modeling the bubble in the presence of an electromagnetic field. We set up this model as a genuine second-order derivative theory by considering a non-trivial boundary term which plays a relevant part in our formulation. The Lagrangian in question is linear in the bubble acceleration and by means of the Ostrogradski-Hamiltonian approach we observed that the theory comprises the management of both first- and second-class constraints. We show thus that our second-order approach is robust allowing for a proper quantization. We found an effective quantum potential which permits to compute bounded states for the system. We comment on the possibility of describing brane world universes by invoking this kind of second-order correction terms.
Akinetic rigid syndrome: An overview
Directory of Open Access Journals (Sweden)
Gupta Praveen
2007-01-01
Full Text Available Akinetic-rigid syndromes can be caused by diverse etiologies. It is vital to separate idiopathic Parkinson′s disease from other neurodegenerative diseases and causes of secondary parkinsonism as it has significant therapeutic implications. However even specialists may misdiagnose nonidiopathic parkinsonism as Parkinson′s disease in a quarter of cases. Often the history may be nonspecific and all investigations may be normal. The diagnosis may thus rest entirely on clinical features. The etiological diagnosis of Akinetic rigid syndrome has critical therapeutic and prognostic implications. Therefore we will review the various etiologies of akinetic rigid syndrome and highlight critical clinical features to aid in differential diagnosis.
Follow-up after repair of vaginal vault prolapse with abdominal colposacropexy
DEFF Research Database (Denmark)
Pilsgaard, K; Mouritsen, L
1999-01-01
% were cured of prolapse symptoms, one had recurrent vault prolapse and was reoperated, four had rectocele. Five patients developed urge incontinence, while urge incontinence, frequency, nocturia and voiding problems were cured in 75%, 80%, 50% and 100%, respectively. One patient developed fecal...
Energy Technology Data Exchange (ETDEWEB)
Redla, Sridhar; Husami, Yahya; Colquhoun, Iain R
2001-10-01
Three cases of middle cranial fossa arachnoid cyst with paradoxical bone changes in the adjacent vault are described, namely, a small middle cranial fossa and pneumosinus dilatans. This association is unusual and unique. The existing literature is reviewed and the probable aetiological factors discussed. Redla, S., Husani, Y. and Colquhoun, I.R. (2001)
The TROVE module: A common element in Telomerase, Ro and Vault ribonucleoproteins
Directory of Open Access Journals (Sweden)
Bateman Alex
2003-10-01
Full Text Available Abstract Background Ribonucleoproteins carry out a variety of important tasks in the cell. In this study we show that a number of these contain a novel module, that we speculate mediates RNA-binding. Results The TROVE module – Telomerase, Ro and Vault module – is found in TEP1 and Ro60 the protein components of three ribonucleoprotein particles. This novel module, consisting of one or more domains, may be involved in binding the RNA components of the three RNPs, which are telomerase RNA, Y RNA and vault RNA. A second conserved region in these proteins is shown to be a member of the vWA domain family. The vWA domain in TEP1 is closely related to the previously recognised vWA domain in VPARP a second component of the vault particle. This vWA domain may mediate interactions between these vault components or bind as yet unidentified components of the RNPs. Conclusions This work suggests that a number of ribonucleoprotein components use a common RNA-binding module. The TROVE module is also found in bacterial ribonucleoproteins suggesting an ancient origin for these ribonucleoproteins.
Reliability and variability of day-to-day vault training measures in artistic gymnastics.
Bradshaw, Elizabeth; Hume, Patria; Calton, Mark; Aisbett, Brad
2010-06-01
Inter-day training reliability and variability in artistic gymnastics vaulting was determined using a customised infra-red timing gate and contact mat timing system. Thirteen Australian high performance gymnasts (eight males and five females) aged 11-23 years were assessed during two consecutive days of normal training. Each gymnast completed a number of vault repetitions per daily session. Inter-day variability of vault run-up velocities (at -18 to -12 m, -12 to -6 m, -6 to -2 m, and -2 to 0 m from the nearest edge of the beat board), and board contact, pre-flight, and table contact times were determined using mixed modelling statistics to account for random (within-subject variability) and fixed effects (gender, number of subjects, number of trials). The difference in the mean (Mdiff) and Cohen's effect sizes for reliability assessment and intra-class correlation coefficients, and the coefficient of variation percentage (CV%) were calculated for variability assessment. Approach velocity (-18 to -2m, CV = 2.4-7.8%) and board contact time (CV = 3.5%) were less variable measures when accounting for day-to-day performance differences, than pre-flight time (CV = 17.7%) and table contact time (CV = 20.5%). While pre-flight and table contact times are relevant training measures, approach velocity and board contact time are more reliable when quantifying vaulting performance.
Grout for closure of the demonstration vault at the US DOE Hanford Facility. Final report
Energy Technology Data Exchange (ETDEWEB)
Wakeley, L.D.; Ernzen, J.J.
1992-08-01
The Waterways Experiment Station (WES) developed a grout to be used as a cold- (nonradioactive) cap or void-fill grout between the solidified low-level waste and the cover blocks of a demonstration vault for disposal of phosphate-sulfate waste (PSW) at the US Department of Energy (DOE) Hanford Facility. The project consisted of formulation and evaluation of candidate grouts and selection of the best candidate grout, followed by a physical scale-model test to verify grout performance under project-specific conditions. Further, the project provided data to verify numerical models (accomplished elsewhere) of stresses and isotherms inside the Hanford demonstration vault. Evaluation of unhardened grout included obtaining data on segregation, bleeding, flow, and working time. For hardened grout, strength, volume stability, temperature rise, and chemical compatibility with surrogate wasteform grout were examined. The grout was formulated to accommodate unique environmental boundary conditions (vault temperature = 45 C) and exacting regulatory requirements (mandating less than 0.1% shrinkage with no expansion and no bleeding); and to remain pumpable for a minimum of 2 hr. A grout consisting of API Class H oil-well cement, an ASTM C 618 Class F fly ash, sodium bentonite clay, and a natural sand from the Hanford area met performance requirements in laboratory studies. It is recommended for use in the DOE Hanford demonstration PSW vault.
Data Vaults: a Database Welcome to Scientiﬁc File Repositories
Ivanova, M.G.; Kargin, Y.; Kersten, M.L.; Manegold, S.; Zhang, Y.; Datcu, M.; Espinoza Molina, D.
2013-01-01
Efficient management and exploration of high-volume scientific file repositories have become pivotal for advancement in science. We propose to demonstrate the Data Vault, an extension of the database system architecture that transparently opens scientific file repositories for efficient in-database
First experiences with electrochemical in-situ desalination of bricks in a church vault construction
DEFF Research Database (Denmark)
Rörig-Dalgaard, Inge
2012-01-01
phase. Salt profiles were made from three different positions in one brick in the church vault construction in Rørby church and satisfying concordance was found between these salt profiles. An area without any original plaster and murals favourable for the construction of a small climate chamber...
Cracking the Vault: Generation and analysis of a MVP knockout mouse model
M.H. Mossink (Marieke)
2003-01-01
markdownabstract__Abstract__ In 1986 a novel, large-sized ribonucleoprotein complex was first described. The barrel-shaped structures were initially detected in preparations of clathrin-coated vesicles from rat liver and because they showed a morphology that resembled the vaulted ceilings in cathed
SHAPE AND CONSTRUCTION OF BRICK VAULTS. CRITERIA, METHODS AND TOOLS FOR A POSSIBLE CATALOGUE
Directory of Open Access Journals (Sweden)
R. Brumana
2017-05-01
Full Text Available The use of cloister vaults in the construction of noble buildings, as covering elements for square or rectangular rooms, is widespread and well-known. The geometric continuity at the intrados makes generally possible the execution all over the span of frescoes, stucco and decorations. The construction of brick vaults, from the late Middle Age, was sped up by limiting the centering to the wooden planks arches that were instrumental in the profile determination. Nowadays, the availability of several procedures, phases and tools for carrying out a survey allows to draw reliable assumptions about the construction methods and the execution time. It is mandatory to determine the properties of the binders, the shape and dimensions of the bricks, and to carry out a comparison between the geometry of the intrados surface and the evidences emerging at the extrados. The support of the laser scanner technique allows to accurately identify the surface profile and thickness. All these indications, in turn, are useful, in view of an interpretation of the structural behavior, to identify weaknesses, and to highlight contributing factors of instability (if any. The paper focuses on a well-documented case, the Magio Grasselli palace in Cremona in which the cloister vaults of two main rooms show different construction systems, although they were built almost at the same time. The thermographic recordings and laser-scanner surveys highlight the various arrangements used for the cloister vaults.
Cranial vault trauma and selective mortality in medieval to early modern Denmark
DEFF Research Database (Denmark)
Boldsen, Jesper L; Milner, George R; Weise, Svenja
2015-01-01
To date, no estimates of the long-term effect of cranial vault fractures on the risk of dying have been generated from historical or prehistoric skeletons. Excess mortality provides a perspective on the efficacy of modern treatment, as well as the human cost of cranial injuries largely related...
Redla, S; Husami, Y; Colquhoun, I R
2001-10-01
Three cases of middle cranial fossa arachnoid cyst with paradoxical bone changes in the adjacent vault are described, namely, a small middle cranial fossa and pneumosinus dilatans. This association is unusual and unique. The existing literature is reviewed and the probable aetiological factors discussed.
Siim Nestor soovitab : Stereo ÖÖ. Mutant Disco. Beats from the Vault. Turbodisko / Siim Nestor
Nestor, Siim, 1974-
2006-01-01
Oma debüütalbumit "Migration" tutvustav ameerika diskor Alex Attias üritustel "Stereo ÖÖ" 19. mail Tallinnas Von Krahlis. Üritustest "Mutant Disco" 19. mail Tallinnas klubis Privé ja Tartus 20. mail klubis Illusion, "Beats from the Vault" 19. mail Tallinnas klubis Võit ja "Turbodisko" 20. mail Tallinnas klubis KuKu
Grout to meet physical and chemical requirements for closure at Hanford grout vaults. Final report
Energy Technology Data Exchange (ETDEWEB)
1994-07-21
The US Army Engineer Waterways Experiment Station (WES) developed a grout based on portland cement, Class F fly ash, and bentonite clay, for the Hanford Grout Vault Program. The purpose of this grout was to fill the void between a wasteform containing 106-AN waste and the vault cover blocks. Following a successful grout development program, heat output, volume change, and compressive strength were monitored with time in simulated repository conditions and in full-depth physical models. This research indicated that the cold-cap grout could achieve and maintain adequate volume stability and other required physical properties in the internal environment of a sealed vault. To determine if contact with 106-AN liquid waste would cause chemical deterioration of the cold-cap grout, cured specimens were immersed in simulated waste. Over a period of 21 days at 150 F, specimens increased in mass without significant changes in volume. X-ray diffraction of reacted specimens revealed crystallization of sodium aluminum silicate hydrate. Scanning electron microscopy used with X-ray fluorescence showed that clusters if this phase had formed in grout pores, increasing grout density and decreasing its effective porosity. Physical and chemical tests collectively indicate a sealing component. However, the Hanford Grout Vault Program was cancelled before completion of this research. This report summarizes close-out Waterways Experiment Station when the Program was cancelled.
The influence of the vaulting table on the handspring front somersault.
Irwin, Gareth; Kerwin, David G
2009-06-01
The traditional "horse" was replaced by a new vaulting "table" in artistic gymnastics competitions in 2001. The aim of this study was to determine whether the table led to a change in vaulting technique. This was achieved by comparing three-dimensional video-based analyses (50Hz) of selected biomechanical discrete and continuous variables across four elite male gymnasts performing a series of handspring front somersault vaults on the traditional horse and the new table. Individual joint and inter-segment coupling (continuous relative phase) were used to quantify techniques used on the two apparatuses. Differences were attributed in part to the design and construction of the new table. No differences were observed for the approach and take-off from the board. Significant differences in hip flexion at board take-off and strike angle on the table were observed. One of the effects of the latter was an increase in vertical take-off velocity compared with the horse. Individual strategies were observed in hip and shoulder coordination patterns that were obscured when group data were considered. Close monitoring of the evolution of skill on this new apparatus is paramount for gymnastics coaching, and further studies of current elite competitive vaulting techniques are required.
Follow-up after repair of vaginal vault prolapse with abdominal colposacropexy
DEFF Research Database (Denmark)
Pilsgaard, K; Mouritsen, L
1999-01-01
BACKGROUND: Vaginal vault prolapse after hysterectomy is a rare complication, with a prevalence of less than 1/2%. The vaginal depth an axis can be restored by colposacropexy with preservation of coital function. The aim of this follow-up study was to assess the results of colposacropexy...
Shape and Construction of Brick Vaults. Criteria, Methods and Tools for a Possible Catalogue
Brumana, R.; Condoleo, P.; Grimoldi, A.; Landi, A. G.
2017-05-01
The use of cloister vaults in the construction of noble buildings, as covering elements for square or rectangular rooms, is widespread and well-known. The geometric continuity at the intrados makes generally possible the execution all over the span of frescoes, stucco and decorations. The construction of brick vaults, from the late Middle Age, was sped up by limiting the centering to the wooden planks arches that were instrumental in the profile determination. Nowadays, the availability of several procedures, phases and tools for carrying out a survey allows to draw reliable assumptions about the construction methods and the execution time. It is mandatory to determine the properties of the binders, the shape and dimensions of the bricks, and to carry out a comparison between the geometry of the intrados surface and the evidences emerging at the extrados. The support of the laser scanner technique allows to accurately identify the surface profile and thickness. All these indications, in turn, are useful, in view of an interpretation of the structural behavior, to identify weaknesses, and to highlight contributing factors of instability (if any). The paper focuses on a well-documented case, the Magio Grasselli palace in Cremona in which the cloister vaults of two main rooms show different construction systems, although they were built almost at the same time. The thermographic recordings and laser-scanner surveys highlight the various arrangements used for the cloister vaults.
Long-term quality-of-life outcome after mesh sacrocolpopexy for vaginal vault prolapse.
LENUS (Irish Health Repository)
Thomas, Arun Z
2009-12-01
To evaluate the long-term outcome of mesh sacrocolpopexy (MSC, which aims to restore normal pelvic floor anatomy to alleviate prolapse related symptoms) and its effect on patient\\'s quality of life, as women with vaginal vault prolapse commonly have various pelvic floor symptoms that can affect urinary, rectal and sexual function.
Siim Nestor soovitab : Stereo ÖÖ. Mutant Disco. Beats from the Vault. Turbodisko / Siim Nestor
Nestor, Siim, 1974-
2006-01-01
Oma debüütalbumit "Migration" tutvustav ameerika diskor Alex Attias üritustel "Stereo ÖÖ" 19. mail Tallinnas Von Krahlis. Üritustest "Mutant Disco" 19. mail Tallinnas klubis Privé ja Tartus 20. mail klubis Illusion, "Beats from the Vault" 19. mail Tallinnas klubis Võit ja "Turbodisko" 20. mail Tallinnas klubis KuKu
Telescoping cylindrical piezoelectric fiber composite actuator assemblies
Allison, Sidney G. (Inventor); Shams, Qamar A. (Inventor); Fox, Robert L. (Inventor); Fox, legal representative, Christopher L. (Inventor); Fox Chattin, legal representative, Melanie L. (Inventor)
2010-01-01
A telescoping actuator assembly includes a plurality of cylindrical actuators in a concentric arrangement. Each cylindrical actuator is at least one piezoelectric fiber composite actuator having a plurality of piezoelectric fibers extending parallel to one another and to the concentric arrangement's longitudinal axis. Each cylindrical actuator is coupled to concentrically-adjacent ones of the cylindrical actuators such that the plurality of cylindrical actuators can experience telescopic movement. An electrical energy source coupled to the cylindrical actuators applies actuation energy thereto to generate the telescopic movement.
Interaction of cylindrically converging diffracted shock with uniform interface
Liang, Yu; Ding, Juchun; Zhai, Zhigang; Si, Ting; Luo, Xisheng
2017-08-01
The Richtmyer-Meshkov instability of an unperturbed air/SF6 interface subjected to a diffracted shock is experimentally studied by high-speed schlieren photography under cylindrical circumstances. The cylindrically converging diffracted shock (CCDS) is produced by a cylindrically uniform shock diffracting around a rigid cylinder(s), and the unperturbed interface is created by a soap film technique. The effects of coupling of multiple rigid cylinders and diverse spacings from the cylinder to interface on a flow field are highlighted. Schlieren images indicate that the amplitude of disturbances on the CCDS increases compared with the local shock radius. After the CCDS impact, a bulge is derived from the interface due to the shock-shock interaction inside the interface, and the number of bulges depends upon the number of cylinders. As the number of cylinders increases, the bulge becomes less pronounced, which is ascribed to additional shock-shock interactions inside the volume. As the distance between the cylinder and interface increases, an air cavity is first observed before the formation of a bulge. The amplitude of perturbation on the interface is found to reduce before the central reflected shock arrival because of the Rayleigh-Taylor stabilization effect. Through equating the pre-interface disturbance of the CCDS to the pre-shock perturbation of the perturbed interface, the initially linear growth rate is theoretically computed based on the impulsive model considering the Bell-Plesset effect. The theoretical results are found to deviate greatly from the experimental counterparts. Instead, taking the post-shock interface amplitude as an initial interface amplitude, the model works well. Therefore, the interface perturbations produced are notably smaller than the disturbances causing them. Moreover, the nonlinear behavior of perturbation growth is estimated by the model considering the Rayleigh-Taylor effect.
Skeletal Rigidity of Phylogenetic Trees
Cheng, Howard; Li, Brian; Risteski, Andrej
2012-01-01
Motivated by geometric origami and the straight skeleton construction, we outline a map between spaces of phylogenetic trees and spaces of planar polygons. The limitations of this map is studied through explicit examples, culminating in proving a structural rigidity result.
Dismantling OPAL's cylindrical magnet core
Laurent Guiraud
2001-01-01
Lifting a handling device for dismounting the pressure bells, which are inside the cylindrical magnet coil on the central section of OPAL, on the right part of the photo. OPAL was a detector on the LEP accelerator, which ran from 1989 to 2000.
Optics Demonstrations Using Cylindrical Lenses
Ivanov, Dragia; Nikolov, Stefan
2015-01-01
In this paper we consider the main properties of cylindrical lenses and propose several demonstrational experiments that can be performed with them. Specifically we use simple glasses full of water to demonstrate some basic geometrical optics principles and phenomena. We also present some less standard experiments that can be performed with such…
Filling of charged cylindrical capillaries
Das, Siddhartha; Chanda, Sourayon; Eijkel, J.C.T.; Tas, N.R.; Chakraborty, Suman; Mitra, Sushanta K.
2014-01-01
We provide an analytical model to describe the filling dynamics of horizontal cylindrical capillaries having charged walls. The presence of surface charge leads to two distinct effects: It leads to a retarding electrical force on the liquid column and also causes a reduced viscous drag force because
Wage rigidity and job creation
Haefke, Christian; Sonntag, Marcus; Rens, Thijs van
2013-01-01
Recent research in macroeconomics emphasizes the role of wage rigidity in accounting for the volatility of unemployment fluctuations. We use worker-level data from the CPS to measure the sensitivity of wages of newly hired workers to changes in aggregate labor market conditions. The wage of new hires, unlike the aggregate wage, is volatile and responds almost one-to-one to changes in labor productivity. We conclude that there is little evidence for wage rigidity in the data.
Caon, Julianna; Holloway, Caroline; Dubash, Rustom; Yuen, Conrad; Aquino-Parsons, Christina
2014-01-01
To document doses received by critical organs during adjuvant high-dose-rate (HDR) vaginal vault brachytherapy. Patients treated with HDR vaginal vault radiation between January 1, 2009, and January 31, 2012, who had a CT simulation with the treatment cylinder in situ were included. The CT scans were retrospectively reviewed and the rectum, sigmoid, small bowel, and bladder were contoured. Standardized plans treating the upper 4 cm of the vaginal vault were used to deliver a total of 21 Gy (Gy) at 0.5 cm from the apex of the vaginal vault in three fractions. There were 41 patients. Median age was 62 years. The median vaginal cylinder diameter was 3 cm. The mean 2cc dose to the rectum, sigmoid, small bowel, and bladder were 5.7, 4.7, 4.0, and 5.6 Gy, respectively. Bladder volume ranged from 67-797cc. Assuming minimal interfraction organ variation, the equivalent dose in 2 Gy/fraction was extrapolated from data and may be near or beyond organ tolerance for rectum, sigmoid, and small bowel in some cases. Spearman correlation found that increased bladder volume was not associated with adjacent organs at risk dose but may be associated with a trend (p=0.06) toward increased bladder dose (R=0.30). This study describes the dose received by adjacent critical structures during vaginal vault HDR brachytherapy. This is important information for documentation in the rare setting of treatment-related toxicity or recurrence. Bladder volume was not associated with dose to adjacent organs. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.
Cranial vault shape in fossil hominids: Fourier descriptors in norma lateralis.
Lestrel, P E; Ohtsuki, F; Wolfe, C A
2010-10-01
Two major views of human evolution have elicited considerable controversy. These are: [1] the "out of Africa" hypothesis and [2] the "multiregional" hypothesis. This paper is an attempt to try to reconcile these two scenarios using hominid cranial vault data. Elliptical Fourier functions (EFFs) were used to describe, in visual and numerical terms, the shape of the human cranial vault in norma lateralis. Using jpeg images, contours of the cranial vault of a large sample of hominid specimens were pre-processed in Photoshop CS and rotated in 2D space (positional-orientation) so that a line drawn from nasion to porion was horizontal. The cranial vault image was then digitized with 72 closely-spaced points and submitted to a specially written routine that computed EFFs normalized by scaling (size-standardization). This ensured that the representation was invariant with respect to starting point, size and orientation. Statistically significant differences were found between the H. sapiens sample and both the H. erectus and H. neanderthalensis samples. In contrast, there were no statistically significant differences between the H. erectus and H. neanderthalensis groups, leading to three conclusions: [1] the similarity in cranial vault shape between H. erectus and H. neanderthalensis suggests a single gradually evolving lineage; [2] The taxon H. heidelbergensis can be embedded into the H. erectus→H. neanderthalensis line; and [3] H. sapiens seems to be a separate evolutionary development and is considered here either as a separate species or as a possible example of an allopatric semispecies (Grant, 1977). The results here suggest that human evolution over the last 2 Ma may turn out to be neither totally multiregional or simply out of Africa but rather represents a considerably more complicated picture.
Directory of Open Access Journals (Sweden)
Xiangyu Li
2015-01-01
Full Text Available An experimental investigation on deformation shape of a cylindrical shell with internal medium subjected to lateral contact explosion was carried out briefly. Deformation shapes at different covered width of lateral explosive were recovered experimentally. Based on the experimental results, a corresponding analytical approach has been undertaken with rigid plastic hinge theory. In the analytical model, the cylindrical shell is divided into end-to-end rigid square bars. Deformation process of the cylindrical shell is described by using the translations and rotations of all rigid square bars. Expressions of the spring force, buckling moment, and deflection angle between adjacent rigid square bars are conducted theoretically. Given the structure parameters of the cylinder and the type of the lateral explosive charge, deformation processes and shapes are reported and discussed using the analytical approach. A good agreement has been obtained between calculated and experimental results, and thus the analytical approach can be considered as a valuable tool in understanding the deformation mechanism and predicting the deformation shapes of the cylindrical shell with internal medium subjected to lateral contact explosion. Finally, parametric studies are carried out to analyze the effects of deformation shape, including the covered width of the lateral explosive, explosive charge material, and distribution of initial velocity.
Directory of Open Access Journals (Sweden)
Upendra K Kar
Full Text Available BACKGROUND: Modifications of adjuvants that induce cell-mediated over antibody-mediated immunity is desired for development of vaccines. Nanocapsules have been found to be viable adjuvants and are amenable to engineering for desired immune responses. We previously showed that natural nanocapsules called vaults can be genetically engineered to elicit Th1 immunity and protection from a mucosal bacterial infection. The purpose of our study was to characterize immunity produced in response to OVA within vault nanoparticles and compare it to another nanocarrier. METHODOLOGY AND PRINCIPAL FINDINGS: We characterized immunity resulting from immunization with the model antigen, ovalbumin (OVA encased in vault nanocapsules and liposomes. We measured OVA responsive CD8(+ and CD4(+ memory T cell responses, cytokine production and antibody titers in vitro and in vivo. We found that immunization with OVA contain in vaults induced a greater number of anti-OVA CD8(+ memory T cells and production of IFNγ plus CD4(+ memory T cells. Also, modification of the vault body could change the immune response compared to OVA encased in liposomes. CONCLUSIONS/SIGNIFICANCE: These experiments show that vault nanocapsules induced strong anti-OVA CD8(+ and CD4(+ T cell memory responses and modest antibody production, which markedly differed from the immune response induced by liposomes. We also found that the vault nanocapsule could be modified to change antibody isotypes in vivo. Thus it is possible to create a vault nanocapsule vaccine that can result in the unique combination of immunogen-responsive CD8(+ and CD4(+ T cell immunity coupled with an IgG1 response for future development of vault nanocapsule-based vaccines against antigens for human pathogens and cancer.
Directory of Open Access Journals (Sweden)
Krzysztof Jacek Gorgolewski
2015-04-01
Full Text Available Here we present NeuroVault — a web based repository that allows researchers to store, share, visualize, and decode statistical maps of the human brain. NeuroVault is easy to use and employs modern web technologies to provide informative visualization of data without the need to install additional software. In addition, it leverages the power of the Neurosynth database to provide cognitive decoding of deposited maps. The data are exposed through a public REST API enabling other services and tools to take advantage of it. NeuroVault is a new resource for researchers interested in conducting meta- and coactivation analyses.
Fatigue and Model Analysis of the CNC Cylindrical Grinder
Directory of Open Access Journals (Sweden)
Lin Jui-Chang
2016-01-01
Full Text Available The purpose of this study is to lower deviation of workpiece by meeting high stability and rigidity to prevent the resonance in producing procedure of the CNC universal cylindrical grinding machine. Using finite element analysis software ABAQUS in grinder machine tools for numerical simulation of several analyses for the following: structural rigidity analysis, optimized design, vibration frequency analysis and fatigue damage analysis. This work aims on state of the transmission of outer diameter spindle to proceed in stress and fatigue life analysis by FE-SAFE Subroutine. The max values of equivalent stress and average amount of displacement in structural rigidity analysis are 0.67(Mpa and 0.92(µm. Optimization design effectively reducing extreme value of stress, the largest decline of about 5.43%. Modal analysis compared with the experimental, the average error percentage was less than 10% of parts. The whole structure error does not exceed 3%. The fatigue life of approximately 1,193,988 times, estimates into real life time can use more than sixty years, from the viewpoint of structural strength, spindle has a good high breaking strength is designed to be safe.
Rigid multibody system dynamics with uncertain rigid bodies
Energy Technology Data Exchange (ETDEWEB)
Batou, A., E-mail: anas.batou@univ-paris-est.fr; Soize, C., E-mail: christian.soize@univ-paris-est.fr [Universite Paris-Est, Laboratoire Modelisation et Simulation Multi Echelle, MSME UMR 8208 CNRS (France)
2012-03-15
This paper is devoted to the construction of a probabilistic model of uncertain rigid bodies for multibody system dynamics. We first construct a stochastic model of an uncertain rigid body by replacing the mass, the center of mass, and the tensor of inertia by random variables. The prior probability distributions of the stochastic model are constructed using the maximum entropy principle under the constraints defined by the available information. The generators of independent realizations corresponding to the prior probability distribution of these random quantities are further developed. Then several uncertain rigid bodies can be linked to each other in order to calculate the random response of a multibody dynamical system. An application is proposed to illustrate the theoretical development.
Improved cylindrical mirror energy analyzer
Baranova, L. A.
2017-03-01
A study has been carried out of the electron-optical properties of improved design of the cylindrical mirror energy analyzer. Both external and internal electrodes of the analyzer are divided into three isolated parts, whereby the potentials on the individual parts can be regulated independently from each other. In symmetric operating mode at identical potentials on the side parts of the electrodes, a significant increase has been obtained in resolving power and light-gathering power of the analyzer compared to the standard design of the cylindrical mirror. In asymmetric operating mode, which is implemented in a linear potential distribution on the external electrode, the conditions have been found under which the linear dispersion of the analyzer increases several times.
Cylindrical solutions in mimetic gravity
Energy Technology Data Exchange (ETDEWEB)
Momeni, Davood; Myrzakulov, Kairat; Myrzakulov, Ratbay [Eurasian National University, Eurasian International Center for Theoretical Physics and Department of General and Theoretical Physics, Astana (Kazakhstan); Raza, Muhammad [COMSATS Institute of Information Technology, Department of Mathematics, Sahiwal (Pakistan)
2016-06-15
This paper is devoted to investigate cylindrical solutions in mimetic gravity. The explicit forms of the metric of this theory, namely mimetic-Kasner (say) have been obtained. In this study we have noticed that the Kasner's family of exact solutions needs to be reconsidered under this type of modified gravity. A no-go theorem is proposed for the exact solutions in the presence of a cosmological constant. (orig.)
Cylindrical Collapse and Gravitational Waves
Herrera, L
2005-01-01
We study the matching conditions for a collapsing anisotropic cylindrical perfect fluid, and we show that its radial pressure is non zero on the surface of the cylinder and proportional to the time dependent part of the field produced by the collapsing fluid. This result resembles the one that arises for the radiation - though non-gravitational - in the spherically symmetric collapsing dissipative fluid, in the diffusion approximation.
Cylindrical Piezoelectric Fiber Composite Actuators
Allison, Sidney G.; Shams, Qamar A.; Fox, Robert L.
2008-01-01
The use of piezoelectric devices has become widespread since Pierre and Jacques Curie discovered the piezoelectric effect in 1880. Examples of current applications of piezoelectric devices include ultrasonic transducers, micro-positioning devices, buzzers, strain sensors, and clocks. The invention of such lightweight, relatively inexpensive piezoceramic-fiber-composite actuators as macro fiber composite (MFC) actuators has made it possible to obtain strains and displacements greater than those that could be generated by prior actuators based on monolithic piezoceramic sheet materials. MFC actuators are flat, flexible actuators designed for bonding to structures to apply or detect strains. Bonding multiple layers of MFC actuators together could increase force capability, but not strain or displacement capability. Cylindrical piezoelectric fiber composite (CPFC) actuators have been invented as alternatives to MFC actuators for applications in which greater forces and/or strains or displacements may be required. In essence, a CPFC actuator is an MFC or other piezoceramic fiber composite actuator fabricated in a cylindrical instead of its conventional flat shape. Cylindrical is used here in the general sense, encompassing shapes that can have circular, elliptical, rectangular or other cross-sectional shapes in the planes perpendicular to their longitudinal axes.
Rigidly foldable origami gadgets and tessellations.
Evans, Thomas A; Lang, Robert J; Magleby, Spencer P; Howell, Larry L
2015-09-01
Rigidly foldable origami allows for motion where all deflection occurs at the crease lines and facilitates the application of origami in materials other than paper. In this paper, we use a recently discovered method for determining rigid foldability to identify existing flat-foldable rigidly foldable tessellations, which are also categorized. We introduce rigidly foldable origami gadgets which may be used to modify existing tessellations or to create new tessellations. Several modified and new rigidly foldable tessellations are presented.
Rigidly foldable origami gadgets and tessellations
Evans, Thomas A.; Lang, Robert J.; Magleby, Spencer P.; Howell, Larry L.
2015-01-01
Rigidly foldable origami allows for motion where all deflection occurs at the crease lines and facilitates the application of origami in materials other than paper. In this paper, we use a recently discovered method for determining rigid foldability to identify existing flat-foldable rigidly foldable tessellations, which are also categorized. We introduce rigidly foldable origami gadgets which may be used to modify existing tessellations or to create new tessellations. Several modified and new rigidly foldable tessellations are presented. PMID:26473037
Bjelić Igor S.; Todorović Dragana J.; Krneta-Nikolić Jelena D.; Lazarević Đorđe R.; Stanković Koviljka Đ.
2016-01-01
This work presents the results of an investigation undertaken to determine the level of natural radioactivity in the traditional building materials used for medieval indoor vaulted constructions in the territory of the central Balkan region. Indoor radiation exposure varies appreciably if it comes from the earth building materials, hence the presence of natural radioisotopes of 226Ra, 232Th, and 40K in masonry vaulted constructions was analyzed using gamma ...
A THERMAL MODEL OF THE IMMOBILIZATION OF LOW-LEVEL RADIOACTIVE WASTE AS GROUT IN CONCRETE VAULTS
Energy Technology Data Exchange (ETDEWEB)
Shadday, M
2008-10-27
Salt solution will be mixed with cement and flyash/slag to form a grout which will be immobilized in above ground concrete vaults. The curing process is exothermic, and a transient thermal model of the pouring and curing process is herein described. A peak temperature limit of 85 C for the curing grout restricts the rate at which it can be poured into a vault. The model is used to optimize the pouring.
Energy Technology Data Exchange (ETDEWEB)
J. R. Morton
2000-09-01
From the 1950s, the Vance Road laboratories had been used for a broad range of nuclear medicine research involving numerous radionuclides. These radionuclides were stored in the a source vault located on the first floor of the facility. The Environmental Survey and Site Assessment Program (ESSAP) of ORISE performed a radiological assessment survey of the source vault after it had been remediated and in preparation for converting the area to office space.
A THERMAL MODEL OF THE IMMOBILIZATION OF LOW-LEVEL RADIOACTIVE WASTE AS GROUT IN CONCRETE VAULTS
Energy Technology Data Exchange (ETDEWEB)
Shadday, M
2008-10-27
Salt solution will be mixed with cement and flyash/slag to form a grout which will be immobilized in above ground concrete vaults. The curing process is exothermic, and a transient thermal model of the pouring and curing process is herein described. A peak temperature limit of 85 C for the curing grout restricts the rate at which it can be poured into a vault. The model is used to optimize the pouring.
Giant osteoma of the skull vault: A rare case of mixed variety
Directory of Open Access Journals (Sweden)
Harisha P.N.
2016-12-01
Full Text Available Osteoma is the most common primary bone tumor in the craniofacial skeleton. However, most of these are small, asymptomatic and arise from the facial bones or in relation to the paranasal sinuses. Cranial vault osteomas, that too giant and symptomatic are much rarer. We report a case of sixty year-old gentleman presented with a very slowly increasing, painless, hard swelling on the left side of his head. Computerized tomography scan showed the left parietal calvarial tumor to be having large exostotic and enostotic components. He underwent an en-bloc excision of the tumor and cranioplasty. Giant, symptomatic cranial vault osteoma with concurrent exostotic and enostotic components is extremely rare. These lesions can be safely and completely excised with careful planning and attention to detail.
First experiences with electrochemical in-situ desalination of bricks in a church vault construction
DEFF Research Database (Denmark)
Rörig-Dalgaard, Inge
2012-01-01
Deterioration of surfaces on building constructions and especially historical constructions caused by presence of salts is a well known problem in Europe and on other continents as well, however there is still a lack of an efficient desalination method. Salt induced deterioration is especially...... problematic in relation to church vault constructions with murals as the surface deterioration can result in loss of valuable cultural heritage. An electrochemical method has been investigated with focus on possible use for desalination of salt loaded vault constructions with murals in laboratory scale....... In the present paper all necessary considerations were made and described prior to electrochemical in-situ desalination. Experiences in getting started with experiments on cultural heritage has been obtained, it needs some extra time and should therefore be considered as an extra step during the preparation...
A lime based mortar for thermal insulation of medieval church vaults
DEFF Research Database (Denmark)
Larsen, P.K.; Hansen, Tessa Kvist
A new mortar for thermal insulation of medieval church vaults was tested in a full scale experiment in Annisse Church, DK. The mortar consists of perlite, a highly porous aggregate, mixed with slaked lime. These materials are compatible with the fired clay bricks and the lime mortar joints....... The lambda-value of the insulation mortar is 0.08 W/m K or twice the lambda-value for mineral wool. The water vapour permeability is equal to a medieval clay brick, and it has three times higher capacity for liquid water absorption. The mortar was applied to the top side of the vaults in a thickness of 10 cm......, and covered by 10 mm lime plaster, reinforced with cattle hair. This assembly can carry the weight of a person, working with maintenance of the roof. Climate measurements confirmed excellent properties in regards to both moisture transport and thermal insulation. Condensation did not occur at any time...
FINGERPRINT-BASED KEY BINDING/RECOVERING SCHEME BASED ON FUZZY VAULT
Institute of Scientific and Technical Information of China (English)
Feng Quan; Su Fei; Cai Anni
2008-01-01
This letter proposes fingerprint-based key binding/recovering with fuzzy vault. Fingerprint minutiae data and the cryptographic key are merged together by a multivariable linear function. First,the minutiae data are bound by a set of random data through the linear function. The number of the function's variables is determined by the required number of matched minutiae. Then, a new key derived from the random data is used to encrypt the cryptographic key. Lastly, the binding data are protected using fuzzy vault scheme. The proposed scheme provides the system with the flexibility to use changeable number of minutiae to bind/recover the protected key and a unified method regardless of the length of the key.
An effective and safe innovation for the management of vault prolapse
Directory of Open Access Journals (Sweden)
Mahendru Rajiv
2010-10-01
Full Text Available Abstract Objective Considering the great variety of techniques and disagreement about the ideal route, there is a need for a simple, safe and effective method for the management of vault prolapse. Study Design 51 cases of post- hysterectomy vault prolapse: 45 following vaginal and 6 after total abdominal hysterectomy were treated surgically by anterior abdominal wall colpopexy with autogenous rectus fascia strips. Results Except for minor complaints like vomiting, fever and urinary retention in 3.92% cases each (n = 2 each, no major complications were encountered. Moreover, no recurrence, thus far, on follow-up. Conclusion Using autogenous rectus fascia strips in anterior abdominal wall colpopexy is not only simple, cheap and effective method of treating apical prolapse but is also devoid of any serious complications as described with other techniques.
Development of a New Cryptographic Construct Using Palmprint-Based Fuzzy Vault
Directory of Open Access Journals (Sweden)
Amioy Kumar
2009-01-01
Full Text Available The combination of cryptology and biometrics has emerged as promising component of information security. Despite the current popularity of palmprint biometric, there has not been any attempt to investigate its usage for the fuzzy vault. This paper therefore investigates the possible usage of palmprint in fuzzy vault to develop a user friendly and reliable crypto system. We suggest the use of both symmetric and asymmetric approach for the encryption. The ciphertext of any document is generated by symmetric cryptosystem; the symmetric key is then encrypted by asymmetric approach. Further, Reed and Solomon codes are used on the generated asymmetric key to provide some error tolerance while decryption. The experimental results from the proposed approach on the palmprint images suggest its possible usage in an automated palmprint-based key generation system.
Llauró, Aida; Guerra, Pablo; Kant, Ravi; Bothner, Brian; Verdaguer, Núria; de Pablo, Pedro J.
2016-10-01
Vault particles are naturally occurring proteinaceous cages with promising application as molecular containers. The use of vaults as functional transporters requires a profound understanding of their structural stability to guarantee the protection and controlled payload delivery. Previous results performed with bulk techniques or at non-physiological conditions have suggested pH as a parameter to control vault dynamics. Here we use Atomic Force Microscopy (AFM) to monitor the structural evolution of individual vault particles while changing the pH in real time. Our experiments show that decreasing the pH of the solution destabilize the barrel region, the central part of vault particles, and leads to the aggregation of the cages. Additional analyses using Quartz-Crystal Microbalance (QCM) and Differential Scanning Fluorimetry (DSF) are consistent with our single molecule AFM experiments. The observed topographical defects suggest that low pH weakens the bonds between adjacent proteins. We hypothesize that the observed effects are related to the strong polar character of the protein-protein lateral interactions. Overall, our study unveils the mechanism for the influence of a biologically relevant range of pHs on the stability and dynamics of vault particles.
Archaeological finds from the vaulted building at Krševica
Directory of Open Access Journals (Sweden)
Popović Petar
2008-01-01
Full Text Available The completely preserved building with barrel vault was discovered in 2008 in the course of investigation of the remains of an urban settlement dating from the 4th /3rd centuries BC at the site Kale in the village Krševica (southeast Serbia. We are presenting in this work the archaeological finds discovered in this structure. They included pottery, worked stone and many skeletons of horses and dogs that are assumed to be the ritual sacrifice.
Treatment vault shielding for a flattening filter-free medical linear accelerator
Energy Technology Data Exchange (ETDEWEB)
Kry, Stephen F; Howell, Rebecca M; Polf, Jerimy; Mohan, Radhe; Vassiliev, Oleg N [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)], E-mail: sfkry@mdanderson.org
2009-03-07
The requirements for shielding a treatment vault with a Varian Clinac 2100 medical linear accelerator operated both with and without the flattening filter were assessed. Basic shielding parameters, such as primary beam tenth-value layers (TVLs), patient scatter fractions, and wall scatter fractions, were calculated using Monte Carlo simulations of 6, 10 and 18 MV beams. Relative integral target current requirements were determined from treatment planning studies of several disease sites with, and without, the flattening filter. The flattened beam shielding data were compared to data published in NCRP Report No. 151, and the unflattened beam shielding data were presented relative to the NCRP data. Finally, the shielding requirements for a typical treatment vault were determined for a single-energy (6 MV) linac and a dual-energy (6 MV/18 MV) linac. With the exception of large-angle patient scatter fractions and wall scatter fractions, the vault shielding parameters were reduced when the flattening filter was removed. Much of this reduction was consistent with the reduced average energy of the FFF beams. Primary beam TVLs were reduced by 12%, on average, and small-angle scatter fractions were reduced by up to 30%. Head leakage was markedly reduced because less integral target current was required to deliver the target dose. For the treatment vault examined in the current study, removal of the flattening filter reduced the required thickness of the primary and secondary barriers by 10-20%, corresponding to 18 m{sup 3} less concrete to shield the single-energy linac and 36 m{sup 3} less concrete to shield the dual-energy linac. Thus, a shielding advantage was found when the linac was operated without the flattening filter. This translates into a reduction in occupational exposure and/or the cost and space of shielding.
Radiological performance assessment for the E-Area Vaults Disposal Facility. Appendices A through M
Energy Technology Data Exchange (ETDEWEB)
Cook, J.R.
1994-04-15
These document contains appendices A-M for the performance assessment. They are A: details of models and assumptions, B: computer codes, C: data tabulation, D: geochemical interactions, E: hydrogeology of the Savannah River Site, F: software QA plans, G: completeness review guide, H: performance assessment peer review panel recommendations, I: suspect soil performance analysis, J: sensitivity/uncertainty analysis, K: vault degradation study, L: description of naval reactor waste disposal, M: porflow input file. (GHH)
3D SURVEYING AND GEOMETRIC ASSESSMENT OF A GOTHIC NAVE VAULTING FROM POINT CLOUDS
Costa-Jover, A.; J. Lluis i Ginovart; Coll-Pla, S.; López Piquer, M.; A. Samper-Sosa; Moreno García, D.; Solís Lorenzo, A. M.
2017-01-01
The development of massive data captures techniques (MDC) in recent years, such as the Terrestrial laser Scanner (TLS), raises the possibility of developing new assessment procedures for architectural heritage. The 3D models that it is able to obtain is a great potential tool, both for conservation purposes and for historical and architectural studies. The paper proposes a simple, non-invasive methodology for the assessment of masonry vaults from point clouds which makes it possible to obtain...
Dubuisson, Jean; Veit-Rubin, Nikolaus; Bouquet de Jolinière, Jean; Dubuisson, Jean-Bernard
2016-01-01
To show an original technique of laparoscopic lateral suspension (LLS) with a precut mesh in a difficult case of vaginal vault prolapse. Step-by-step descriptions of the technique using videos (educational video). Vaginal vault prolapse affects up to 1% of patients who had a hysterectomy. Sacrocolpopexy is considered the gold standard in the treatment of apical pelvic organ prolapse. However, dissection at the level of the promontory may be challenging, particularly in obese patients or when an anatomic variation exists. This may be associated with rare but serious neurologic or ureteral morbidity as well as life-threatening vascular injury. LLS with mesh represents an alternative procedure, avoiding dissection at the promontory. The originality of this video is to describe the procedure of LLS in a difficult case of vaginal vault prolapse related to adhesions and difficulties of fascia cleavage. The use of a precut cross-shaped mesh simplified the technique and facilitated the attachment of the mesh to the fascia and the lateral suspension for a smaller period of time. This point is not negligible, especially in cases with technical difficulties. Institutional review board approval was obtained through the local ethics committee of Geneva University Hospitals (Canadian Task Force classification III). After dissections, positioning of the mesh on the dome and on the anterior and posterior vaginal walls is explained. The out-in technique of lateral suspension with the specific mesh is described. In this difficult case of vaginal vault prolapse, the LLS using a precut cross-shaped mesh was placed in good conditions, providing the patient with a minimum risk of complications and with the benefits of minimally invasive approach. Copyright © 2016 AAGL. Published by Elsevier Inc. All rights reserved.
Secure voice-based authentication for mobile devices: vaulted voice verification
Johnson, R. C.; Scheirer, Walter J.; Boult, Terrance E.
2013-05-01
As the use of biometrics becomes more wide-spread, the privacy concerns that stem from the use of biometrics are becoming more apparent. As the usage of mobile devices grows, so does the desire to implement biometric identification into such devices. A large majority of mobile devices being used are mobile phones. While work is being done to implement different types of biometrics into mobile phones, such as photo based biometrics, voice is a more natural choice. The idea of voice as a biometric identifier has been around a long time. One of the major concerns with using voice as an identifier is the instability of voice. We have developed a protocol that addresses those instabilities and preserves privacy. This paper describes a novel protocol that allows a user to authenticate using voice on a mobile/remote device without compromising their privacy. We first discuss the Vaulted Verification protocol, which has recently been introduced in research literature, and then describe its limitations. We then introduce a novel adaptation and extension of the Vaulted Verification protocol to voice, dubbed Vaulted Voice Verification (V3). Following that we show a performance evaluation and then conclude with a discussion of security and future work.
Effect of the upper limbs muscles activity on the mechanical energy gain in pole vaulting.
Frère, Julien; Göpfert, Beat; Slawinski, Jean; Tourny-chollet, Claire
2012-04-01
The shoulder muscles are highly solicited in pole vaulting and may afford energy gain. The objective of this study was to determine the bilateral muscle activity of the upper-limbs to explain the actions performed by the vaulter to bend the pole and store elastic energy. Seven experienced athletes performed 5-10 vaults which were recorded using two video cameras (50Hz). The mechanical energy of the centre of gravity (CG) was computed, while surface electromyographic (EMG) profiles were recorded from 5 muscles bilateral: deltoideus, infraspinatus, biceps brachii, triceps, and latissimus dorsi muscles. The level of intensity from EMG profile was retained in four sub phases between take-off (TO1) and complete pole straightening (PS). The athletes had a mean mechanical energy gain of 22% throughout the pole vault, while the intensities of deltoideus, biceps brachii, and latissimus dorsi muscles were sub phases-dependent (pmechanical energy of the vaulter could be linked to an increase in muscle activation, especially from latissimusdorsi muscles. Copyright Â© 2011 Elsevier Ltd. All rights reserved.
DEFF Research Database (Denmark)
Rijkhoff, Jan
2008-01-01
, Non-Verb, Modifier), there are also flexible word classes within the rigid lexical category Noun (Set Noun, Sort Noun, General Noun). Members of flexible word classes are characterized by their vague semantics, which in the case of nouns means that values for the semantic features Shape...
DEFF Research Database (Denmark)
Rijkhoff, Jan
2010-01-01
This article argues that in addition to the major flexible lexical categories in Hengeveld’s classification of parts of speech systems (Contentive, Non-Verb, Modifier), there are also flexible word classes within the rigid lexical category Noun (Set Noun, Sort Noun, General Noun). Members...
Rigidity-tuning conductive elastomer
Shan, Wanliang; Diller, Stuart; Tutcuoglu, Abbas; Majidi, Carmel
2015-06-01
We introduce a conductive propylene-based elastomer (cPBE) that rapidly and reversibly changes its mechanical rigidity when powered with electrical current. The elastomer is rigid in its natural state, with an elastic (Young’s) modulus of 175.5 MPa, and softens when electrically activated. By embedding the cPBE in an electrically insulating sheet of polydimethylsiloxane (PDMS), we create a cPBE-PDMS composite that can reversibly change its tensile modulus between 37 and 1.5 MPa. The rigidity change takes ˜6 s and is initiated when a 100 V voltage drop is applied across the two ends of the cPBE film. This magnitude of change in elastic rigidity is similar to that observed in natural skeletal muscle and catch connective tissue. We characterize the tunable load-bearing capability of the cPBE-PDMS composite with a motorized tensile test and deadweight experiment. Lastly, we demonstrate the ability to control the routing of internal forces by embedding several cPBE-PDMS ‘active tendons’ into a soft robotic pneumatic bending actuator. Selectively activating the artificial tendons controls the neutral axis and direction of bending during inflation.
Rigid coupling is also flexible
Appleberry, W. T.
1978-01-01
Spring-loaded coupling is rigid under light loads and swivels under higher loads. Break-out point can be set at any desired value by selecting appropriate preload springs. Coupling requires no cushions or elastomeric joints that limit temperature range.
The compliance contact model of cylindrical joints with clearances
Institute of Scientific and Technical Information of China (English)
Caishan Liu; Ke Zhang; Lei Yang; Keren Wang
2005-01-01
This paper is concerned with the determination of the normal force-displacement (NFD) relation for the contact problem of cylindrical joints with clearance. A simple formulation for this contact problem is developed by modeling the pin as a rigid wedge and the elastic plate as a simple Winkler elastic foundation. The numerical results show that the normal displacement relation based on Hertz theory is only valid for the case of large clearance with a small normal load, and the NFD relation based on Persson theory is only effective in the case of very small clearance. The proposed approximate model in this paper gives better results than Hertz theory and Persson theory in a large range of clearances as seen from the comparison with the results of FEM.
First and second sound in cylindrically trapped gases.
Bertaina, G; Pitaevskii, L; Stringari, S
2010-10-08
We investigate the propagation of density and temperature waves in a cylindrically trapped gas with radial harmonic confinement. Starting from two-fluid hydrodynamic theory we derive effective 1D equations for the chemical potential and the temperature which explicitly account for the effects of viscosity and thermal conductivity. Differently from quantum fluids confined by rigid walls, the harmonic confinement allows for the propagation of both first and second sound in the long wavelength limit. We provide quantitative predictions for the two sound velocities of a superfluid Fermi gas at unitarity. For shorter wavelengths we discover a new surprising class of excitations continuously spread over a finite interval of frequencies. This results in a nondissipative damping in the response function which is analytically calculated in the limiting case of a classical ideal gas.
Buckling Characteristics of Cylindrical Pipes
Institute of Scientific and Technical Information of China (English)
Toshiaki Sakurai
2015-01-01
This paper describes the buckling pattern of the body frame by energy absorbed efficiency of crashworthiness related toresearch of the buckling characteristics of aluminum cylindrical pipes with various diameters formed mechanical tools. Experimentswere performed by the quasi-static test without lubrication between specimen and equipment. According to the change in the radiusversus thickness of the specimen, the buckling phenomena are transformed from folding to bellows and the rate of energy absorptionis understood. In crashworthiness, frames are characterized by the folding among three patterns from the absorbed energy efficiencypoint of view and weight reduction. With the development of new types of transport such as electric vehicles, innovated bodystructure should be designed.
Energy Technology Data Exchange (ETDEWEB)
Langton, C
2008-08-19
This report summarizes the preliminary results of a durability analysis performed by SIMCO Technologies Inc. to assess the effects of contacting saltstone Vaults 1/4 and Disposal Unit 2 concretes with highly alkaline solutions containing high concentrations of dissolved sulfate. The STADIUM{reg_sign} code and data from two surrogate concretes which are similar to the Vaults 1/4 and Disposal Unit 2 concretes were used in the preliminary durability analysis. Simulation results for these surrogate concrete mixes are provided in this report. The STADIUM{reg_sign} code will be re-run using transport properties measured for the SRS Vaults 1/4 and Disposal Unit 2 concrete samples after SIMCO personnel complete characterization testing on samples of these materials. Simulation results which utilize properties measured for samples of Vaults 1/4 and Disposal Unit 2 concretes will be provided in Revision 1 of this report after property data become available. The modeling performed to date provided the following information on two concrete mixes that will be used to support the Saltstone PA: (1) Relationship between the rate of advancement of the sulfate front (depth of sulfate ion penetration into the concrete) and the rate of change of the concrete permeability and diffusivity. (2) Relationship between the sulfate ion concentration in the corrosive leachate and the rate of the sulfate front progression. (3) Equation describing the change in hydraulic properties (hydraulic conductivity and diffusivity) as a function of sulfate ion concentration in the corrosive leachate. These results have been incorporated into the current Saltstone PA analysis by G. Flach (Flach, 2008). In addition, samples of the Saltstone Vaults 1/4 and Disposal Unit 2 concretes have been prepared by SIMCO Technologies, Inc. Transport and physical properties for these materials are currently being measured and sulfate exposure testing to three high alkaline, high sulfate leachates provided by SRNL is
EFFECTS OF RUN-UP VELOCITY ON PERFORMANCE, KINEMATICS, AND ENERGY EXCHANGES IN THE POLE VAULT
Directory of Open Access Journals (Sweden)
Nicholas P. Linthorne
2012-06-01
Full Text Available This study examined the effect of run-up velocity on the peak height achieved by the athlete in the pole vault and on the corresponding changes in the athlete's kinematics and energy exchanges. Seventeen jumps by an experienced male pole vaulter were video recorded in the sagittal plane and a wide range of run-up velocities (4.5-8.5 m/s was obtained by setting the length of the athlete's run-up (2-16 steps. A selection of performance variables, kinematic variables, energy variables, and pole variables were calculated from the digitized video data. We found that the athlete's peak height increased linearly at a rate of 0.54 m per 1 m/s increase in run-up velocity and this increase was achieved through a combination of a greater grip height and a greater push height. At the athlete's competition run-up velocity (8.4 m/s about one third of the rate of increase in peak height arose from an increase in grip height and about two thirds arose from an increase in push height. Across the range of run-up velocities examined here the athlete always performed the basic actions of running, planting, jumping, and inverting on the pole. However, he made minor systematic changes to his jumping kinematics, vaulting kinematics, and selection of pole characteristics as the run-up velocity increased. The increase in run-up velocity and changes in the athlete's vaulting kinematics resulted in substantial changes to the magnitudes of the energy exchanges during the vault. A faster run-up produced a greater loss of energy during the take-off, but this loss was not sufficient to negate the increase in run-up velocity and the increase in work done by the athlete during the pole support phase. The athlete therefore always had a net energy gain during the vault. However, the magnitude of this gain decreased slightly as run-up velocity increased
Interactive Perception of Rigid and Non-Rigid Objects
Directory of Open Access Journals (Sweden)
Bryan Willimon
2012-12-01
Full Text Available This paper explores the concept of interactive perception, in which sensing guides manipulation, in the context of extracting and classifying unknown objects within a cluttered environment. In the proposed approach, a pile of objects lies on a flat background, and the goal of the robot is to isolate, interact with, and classify each object so that its properties can be obtained. The algorithm considers each object to be classified using color, shape, and flexibility. The approach works with a variety of objects relevant to service robot applications, including both rigid objects such as bottles, cans, and pliers as well as non‐rigid objects such as soft toy animals, socks, and shoes. Experiments on a number of different piles of objects demonstrate the ability of efficiently isolating and classifying each item through interaction.
Evaluation of transmitting performance of cylindrical polycapillary
Xiaoyan, Lin; Yude, Li; Guotai, Tan; Tianxi, Sun
2007-03-01
Based on a detailed ray-tracing code for capillary optics, a MATLAB program for the simulation of X-ray transmission in a cylindrical polycapillary is described. The simulated and experimental results for the spatial distributions and power density gain of the X-rays in the beam guided through a cylindrical polycapillary are in good agreement, and the results show that the spatial distribution of the X-rays in the beam guided through a cylindrical polycapillary is uneven.
Array gain for a cylindrical array with baffle scatter effects.
Bertilone, Derek C; Killeen, Damien S; Bao, Chaoying
2007-11-01
Cylindrical arrays used in sonar for passive underwater surveillance often have sensors surrounding a cylindrical metal baffle. In some operational sonars, the phones in each stave (i.e., each line of phones aligned with the cylinder axis) are hardwired together so that the array is equivalent to a baffled circular array of directional elements, where each element corresponds to a line array of omnidirectional phones steered to broadside. In this paper a model is introduced for computing the array gain of such an array at high frequencies, which incorporates baffle scatter using infinite, rigid cylinder scattering theory, and with ambient noise described by an angular spectral density function. In practice the phones are often offset from the baffle surface, and the acoustic field sampled by the staves is distorted at high frequencies due to interference between the incident and scattered fields. Examples are given to illustrate the resulting array gain degradation, using three noise distributions that are frequently used in sonar performance modeling: three-dimensional isotropic, two-dimensional isotropic, and surface dipole noise.
Ultrasound cylindrical phased array for transoesophageal thermal therapy: initial studies
Energy Technology Data Exchange (ETDEWEB)
Melodelima, David [INSERM, Unite 556, 151 Cours Albert Thomas, 69424 Lyon (France); Lafon, Cyril [INSERM, Unite 556, 151 Cours Albert Thomas, 69424 Lyon (France); Prat, Frederic [Centre Hospitalier Bicetre, 78 Avenue General Leclerc, 94275 Le Kremlin Bicetre (France); Birer, Alain [INSERM, Unite 556, 151 Cours Albert Thomas, 69424 Lyon (France); Cathignol, Dominique [INSERM, Unite 556, 151 Cours Albert Thomas, 69424 Lyon (France)
2002-12-07
This work was undertaken to investigate the feasibility of constructing a cylindrical phased array composed of 64 elements spread around the periphery (OD 10.6 mm) for transoesophageal ultrasound thermotherapy. The underlying operating principle of this applicator is to rotate a plane ultrasound beam electronically. For this purpose, eight adjacent transducers were successively excited with appropriate delay times so as to generate a plane wave. The exposure direction was changed by exciting a different set of eight elements. For these feasibility studies, we used a cylindrical prototype (OD 10.6 mm) composed of 16 elementary transducers distributed over a quarter of the cylinder, all operating at 4.55 MHz. The active part was mechanically reinforced by a rigid damper structure behind the transducers. It was shown that an ultrasound field similar to that emitted by a plane transducer could be generated. Ex vivo experiments on pig's liver demonstrated that the ultrasound beam could be accurately rotated to generate sector-based lesions to a suitable depth (up to 19 mm). Throughout these experiments, exposures lasting 20 s were delivered at an acoustic intensity of 17 W cm{sup -2}. By varying the power from exposure to exposure, the depth of the lesion at different angles could be controlled.
Jackson, M I; Hiley, M J; Yeadon, M R
2011-10-13
In the table contact phase of gymnastics vaulting both dynamic and static friction act. The purpose of this study was to develop a method of simulating Coulomb friction that incorporated both dynamic and static phases and to compare the results with those obtained using a pseudo-Coulomb implementation of friction when applied to the table contact phase of gymnastics vaulting. Kinematic data were obtained from an elite level gymnast performing handspring straight somersault vaults using a Vicon optoelectronic motion capture system. An angle-driven computer model of vaulting that simulated the interaction between a seven segment gymnast and a single segment vaulting table during the table contact phase of the vault was developed. Both dynamic and static friction were incorporated within the model by switching between two implementations of the tangential frictional force. Two vaulting trials were used to determine the model parameters using a genetic algorithm to match simulations to recorded performances. A third independent trial was used to evaluate the model and close agreement was found between the simulation and the recorded performance with an overall difference of 13.5%. The two-state simulation model was found to be capable of replicating performance at take-off and also of replicating key contact phase features such as the normal and tangential motion of the hands. The results of the two-state model were compared to those using a pseudo-Coulomb friction implementation within the simulation model. The two-state model achieved similar overall results to those of the pseudo-Coulomb model but obtained solutions more rapidly. Copyright © 2011 Elsevier Ltd. All rights reserved.
Ingestion of cylindrical batteries and its management.
Tien, Tony; Tanwar, Sudeep
2017-01-17
In contrast to the ingestion of coin batteries, the ingestion of cylindrical batteries is an uncommon medical presentation. Owing to their larger size, cylindrical battery ingestion can lead to serious complications including intestinal haemorrhage, bowel obstruction, bowel perforation, peritonitis and even death. We discuss the case of a 17-year-old girl who presented after swallowing three cylindrical batteries. Her medical history included depression and previous battery ingestion that required surgical removal. During this presentation however, these ingested batteries were removed endoscopically at oesophagogastroduodenoscopy and ileocolonoscopy. The patient was subsequently discharged without complication. This paper discusses the complications and management of cylindrical battery ingestion. 2017 BMJ Publishing Group Ltd.
Rigid subsets of symplectic manifolds
Entov, Michael
2007-01-01
We show that there is an hierarchy of intersection rigidity properties of sets in a closed symplectic manifold: some sets cannot be displaced by symplectomorphisms from more sets than the others. We also find new examples of rigidity of intersections involving, in particular, specific fibers of moment maps of Hamiltonian torus actions, monotone Lagrangian submanifolds (following the previous work of P.Albers) as well as certain, possibly singular, sets defined in terms of Poisson-commutative subalgebras of smooth functions. In addition, we get some geometric obstructions to semi-simplicity of the quantum homology of symplectic manifolds. The proofs are based on the Floer-theoretical machinery of partial symplectic quasi-states.
Rigidity spectrum of Forbush decrease
Sakakibara, S.; Munakata, K.; Nagashima, K.
1985-01-01
Using data from neutron monitors and muon telescopes at surface and underground stations, the average rigidity spectrum of Forbush decreases (Fds) during the period of 1978-1982 were obtained. Thirty eight Ed-events are classified into two groups Hard Fd and Soft Fd according to size of Fd at Sakashita station. It is found that a spectral form of fractional-power type (P to the-gamma sub 1 (P+P sub c) to the -gamma sub2) is more suitable for the present purpose than that of power-exponential type or of power type with an upper limiting rigidity. The best fitted spectrum of fractional-power type is expressed by gamma sub1 = 0.37, gamma sub2 = 0.89 and P subc = 10 GV for Hard Fd and gamma sub1 = 0.77, gamma sub2 = 1.02 and P sub c - 14GV for Soft Fd.
Rigid body dynamics of mechanisms
Hahn, Hubert
2003-01-01
The second volume of Rigid Body Dynamics of Mechanisms covers applications via a systematic method for deriving model equations of planar and spatial mechanisms. The necessary theoretical foundations have been laid in the first volume that introduces the theoretical mechanical aspects of mechatronic systems. Here the focus is on the application of the modeling methodology to various examples of rigid-body mechanisms, simple planar ones as well as more challenging spatial problems. A rich variety of joint models, active constraints, plus active and passive force elements is treated. The book is intended for self-study by working engineers and students concerned with the control of mechanical systems, i.e. robotics, mechatronics, vehicles, and machine tools. The examples included are a likely source from which to choose models for university lectures.
The Mechanical Properties of Medium Density Rigid Polyurethane Biofoam
Directory of Open Access Journals (Sweden)
Ali Ernie Suzana
2016-01-01
Full Text Available This paper described the effect of empty fruit bunch (EFB loading in the medium density rigid foam, which was prepared from the palm kernel oil based polyol. The grounded 300μm EFB fiber was used as filler and its composition were varied from 3, 6, 9 and 12 weight percent. EFB filled PU shown good dimensional stability at 70°C and -15°C due expending and shrinking percentage are less than 0.8% and 0.4% respectively. The mechanical properties were increased linearly with the EFB loading until it reached an optimum percentage of the EFB. SEM images shows the usage of big size cylindrical particle suggested that the fiber pull out will responsible for the synergistic effect of flexibility and strength of the biofoam produced.
El Gallaf, Anas; Touihri, Ridha; Henry, Daniel; Ben Hadid, Hamda
2009-11-01
Three-dimensional simulations of the buoyant convection in a cylindrical container heated from below are presented. Both the thresholds for the onset of the convection and the nonlinear evolution of this convection are calculated. The simulations concern two configurations: a cavity with a rigid upper surface (Rigid-Rigid case) and a cavity with a non-constrained free surface (Rigid-Free case). The results show a similar variation of the primary thresholds with the aspect ratio for the two configurations. In contrast, the nonlinear evolution of the convection is much changed between the two configurations. In particular, subcritical secondary branches with a very large subcriticity are obtained in the R-F case. To cite this article: A. El Gallaf et al., C. R. Mecanique 337 (2009).
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
A derivation of an analytical expression for the inviscid velocity field induced by a single right-handed helical vortex filament is presented. The vortex filament moves uniformly and rigidly without change of form in a cylindrical tube, where the vortex filament rotates around its axis with a constant angular velocity and translates along its axis with a constant translational velocity. The key to solve the problem is to set up a moving cylindrical coordinate system fixed on the vortex filament. The result shows that the velocity field is a time-periodic function, and may degenerate into Okulovs's formula when the helical vortex filament slips along the filament itself or stays immobile.
Directory of Open Access Journals (Sweden)
Roman Farana
2015-03-01
Full Text Available Background: A vaulting performance takes a short time and it is influenced by and affects the quantity of mechanical variables. The significant relationships between the vaulting score and specific aspects of the gymnast's vault should conduct coaches to monitor these variables as a part of training or routine testing. Objective: The aim of the current study was to determine the biomechanical variables that are related to a successful performance of the Akopian vaults performed by top level male gymnasts during the World Cup competition. Methods: Fifteen top-level male gymnasts participated in this study. For the 3D analysis, two digital camcorders with a frame rate of 50 Hz were used. The data were digitized by the Simi motion software. The Hay and Reid method was used to identify the biomechanical variables that determine the linear and angular motions of the handspring and front somersault vaults. A correlation analysis was used to establish the relationship between the biomechanical variables and the judges' scores. The level of statistical significance was determined at the value of p < .05. Results: In the Akopian vaults, in five out of 24 variables arising from the deterministic model showed a significant relationship to the score. A significant correlation was found in the maximum height of the body center of mass in the second flight phase, in the height of the body center of mass at the mat touchdown, in the change of the vertical velocity during the take-off from the vaulting table, and in the duration of the second flight phase. Conclusions: The results of the study suggest that a successful execution of Akopian vaults and the achievement of a higher score required: to maximize the change in vertical velocity in the table contact phase and maximize vertical velocity in the table take-off phase; to maximize the amplitude of the second flight phase, which is determined by the duration of the second flight phase, by the maximum
Turbulence in the cylindrical slab
Energy Technology Data Exchange (ETDEWEB)
Gentle, K. W.; Rowan, W. L.; Williams, C. B.; Brookman, M. W. [Institute of Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)
2014-09-15
The cylindrical slab was the first and simplest model of intrinsically unstable microturbulence. The Helimak is an experimental realization of this model. Although finite, it is sufficiently large to escape boundary effects, with dimensionless parameters similar to those of a tokamak edge or scrape off layer. The essential drive is interchange-like, a pressure gradient with unfavorable magnetic curvature, leading to a non-linearly saturated state of large-amplitude turbulence, Δn{sub rms}/n ∼ 0.5. The nonlinear processes governing this saturation are unique, unlike any of those posited for the much weaker turbulence typical of confined plasma, e.g., in a tokamak. Neither linear stability theory, quasi-linear theory, zonal flows, nor flow shear stabilization is consistent with the observations. The mechanisms determining the non-linearly saturated state constitute an important challenge to our understanding of strongly nonlinear systems.
The Casimir Torque on a Cylindrical Gear
Vaidya, Varun
2013-01-01
We utilize Effective Field Theory(EFT) techniques to calculate the casimir torque on a cylindrical gear in the presence of a polarizable but neutral object. We present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.
Casimir torque on a cylindrical gear
Vaidya, Varun
2014-08-01
I utilize effective field theory(EFT) techniques to calculate the Casimir torque on a cylindrical gear in the presence of a polarizable but neutral object and present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.
Synthesis of Phased Cylindrical Arc Antenna Arrays
Directory of Open Access Journals (Sweden)
Hussein Rammal
2009-01-01
Full Text Available This paper describes a new approach to synthesize cylindrical antenna arrays controlled by the phase excitation, to synthesize directive lobe and multilobe patterns with steered zero. The proposed method is based on iterative minimization of a function that incorporates constraints imposed in each direction. An 8-element cylindrical antenna has been simulated and tested for various types of beam configurations.
On cylindrical near-field scanning techniques
DEFF Research Database (Denmark)
Appel-Hansen, Jørgen
1980-01-01
The agreement between the coupling equations obtained in the literature by using the reciprocity theorem and the scattering matrix formulation is demonstrated. The field is expanded in cylindrical vector wave functions and the addition theorem for these functions is used. The communication may se...... serve as a tutorial introduction to the cylindrical scanning techniques....
Directory of Open Access Journals (Sweden)
Jansen David A
2011-09-01
Full Text Available Abstract Background Craniosynostosis (CSS results from the premature closure of one or more cranial sutures, leading to deformed calvaria at birth. It is a common finding in children with an incidence of one in 2000 births. Surgery is required in order to release the synostotic constraint and promote normal calvaria growth. Cranial vault remodeling is the surgical approach to CSS repair at our institution and it involves excision of the frontal, parietal, and occipital bones. The purpose of this article is to describe the post-operative course of infants and children admitted to our PICU after undergoing cranial vault remodeling for primary CSS. Findings Complete data was available for analyses in only 82 patients, 44 males (M and 38 females (F; M: F ratio was 1:1.2. Patients (pts age in months (mo ranged from 2 mo to 132 mo, mean 18.2 ±-24.9 mo and weights (wt ranged from 4.7 kg to 31.4 kg, mean 10.24 ± 5.5 Kg.. Duration of surgery (DOS ranged from 70 minutes to 573 minutes mean 331.6 ± 89.0 minutes. No significant correlation exist between duration of surgery, suture category, patient's age or use of blood products (P > 0.05. IOP blood loss was higher in older pts (P 3 days in 32%. Pts with fever had prolonged LOS (P Conclusions Post-op morbidities from increased use of blood products can be minimized if cranial vault remodeling is done at a younger age in patients with primary CSS. PICU length of stay is determined in part by post-op pyrexia and it can be reduced if extensive evaluations of post-op fever are avoided.
Energy Technology Data Exchange (ETDEWEB)
Pickett, C.A.; Barham, M.A.; Gafford, T.A.; Hutchinson, D.P.; Jordan, J.K.; Maxey, L.C.; Moran, B.W.; Muhs, J.; Nodine, R.; Simpson, M.L. [and others
1994-12-08
Nearly all facilities that store hazardous (radioactive or non-radioactive) materials must comply with prevailing federal, state, and local laws. These laws usually have components that require periodic physical inspections to insure that all materials remain safely and securely stored. The inspections are generally labor intensive, slow, put personnel at risk, and only find anomalies after they have occurred. The system described in this paper was developed for monitoring stored nuclear materials resulting from weapons dismantlement, but its applications extend to any storage facility that meets the above criteria. The traditional special nuclear material (SNM) accountability programs, that are currently used within most of the Department of Energy (DOE) complex, require the physical entry of highly trained personnel into SNM storage vaults. This imposes the need for additional security measures, which typically mandate that extra security personnel be present while SNM inventories are performed. These requirements increase labor costs and put additional personnel at risk to radiation exposure. In some cases, individuals have received radiation exposure equivalent to the annual maximum during just one inventory verification. With increasing overhead costs, the current system is rapidly becoming too expensive to operate, the need for an automated method of inventory verification is evident. The Continuous Automated Vault Inventory System (CAVIS) described in this paper was designed and prototyped as a low cost, highly reliable, and user friendly system that is capable of providing, real-time weight, gamma. and neutron energy confirmation from each item stored in a SNM vault. This paper describes the sensor technologies, the CAVIS prototype system (built at Y- 12 for highly enriched uranium storage), the technical requirements that must be achieved to assure successful implementation, and descriptions of sensor technologies needed for a plutonium facility.
Robleda, P. G.; Caroti, G.; Martínez-Espejo Zaragoza, I.; Piemonte, A.
2016-06-01
Sometimes it is difficult to represent "on paper" the existing reality of architectonic elements, depending on the complexity of his geometry, but not only in cases with complex geometries: non-relief surfaces, can need a "special planar format" for its graphical representation. Nowadays, there are a lot of methods to obtain tridimensional recovery of our Cultural Heritage with different ranges of the relationship accuracy / costs, even getting high accuracy using "low-cost" recovery methods as digital photogrammetry, which allow us easily to obtain a graphical representation "on paper": ortho-images of different points of view. This can be useful for many purposes but, for others, an orthographic projection is not really very interesting. In non-site restoration tasks of frescoed vaults, a "planar format" representation in needed to see in true magnitude the paintings represented on the intrados vault, because of the general methodology used: gluing the fresco on a fabric, removing the fresco-fabric from the support, moving to laboratory, removing the fresco from the fabric, restoring the fresco, gluing back the restored fresco on another fabric, laying the restored fresco on the original location and removing the fabric. Because of this, many times, an unfolded model is needed, in a similar way a cylinder or cone can be unfolded, but in this case with a texture included: UV unwrapping. Unfold and fold-back processes, can be especially interesting in restoration field of frescoed vaults and domes at: chromatic recovery of paintings, reconstruction of partially missed geometries, transference of paintings on surfaces, etc.
Simple Riemannian surfaces are scattering rigid
Wen, Haomin
2015-01-01
Scattering rigidity of a Riemannian manifold allows one to tell the metric of a manifold with boundary by looking at the directions of geodesics at the boundary. Lens rigidity allows one to tell the metric of a manifold with boundary from the same information plus the length of geodesics. There are a variety of results about lens rigidity but very little is known for scattering rigidity. We will discuss the subtle difference between these two types of rigidities and prove that they are equiva...
A Potential Model for Cylindrical Pores
Institute of Scientific and Technical Information of China (English)
张现仁; 汪文川
2001-01-01
An analytical potential for cylindrical pores has been derived by introducing a variational method into the integration for the calculation of the interaction energy between the wall molecules and a test molecule, all of which are represented by Lennard-Jones potential. The model proposed gives good fit to the results from the cylindrical surface model and the pseudoatom model. To test the potential proposed rigorously, we have carried out grand canonical ensemble Monte Carlo(GCMC) simulation of nitrogen in the MCM-41 pore at 77 K, and compared the simulated adsorption isotherm with the experimental data reported in the literature. The simulated isotherm from our model is in almost qualitative agreement with experiment. Consequently, the model proposed provides an explicit and accurate description of cylindrical pores represented by the Lennard-Jones potential. Moreover, the model can be easily applied to a variety of cylindrical pores, ranging from cylindrical surface to finite thickness walls, in both theoretical studies and computer simulations.
Radiological performance assessment for the E-Area Vaults Disposal Facility
Energy Technology Data Exchange (ETDEWEB)
Cook, J.R.
2000-04-11
This report is the first revision to ``Radiological Performance Assessment for the E-Area Vaults Disposal Facility, Revision 0'', which was issued in April 1994 and received conditional DOE approval in September 1994. The title of this report has been changed to conform to the current name of the facility. The revision incorporates improved groundwater modeling methodology, which includes a large data base of site specific geotechnical data, and special Analyses on disposal of cement-based wasteforms and naval wastes, issued after publication of Revision 0.
Cavern/Vault Disposal Concepts and Thermal Calculations for Direct Disposal of 37-PWR Size DPCs
Energy Technology Data Exchange (ETDEWEB)
Hardin, Ernest [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hadgu, Teklu [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Clayton, Daniel James [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
2015-03-01
This report provides two sets of calculations not presented in previous reports on the technical feasibility of spent nuclear fuel (SNF) disposal directly in dual-purpose canisters (DPCs): 1) thermal calculations for reference disposal concepts using larger 37-PWR size DPC-based waste packages, and 2) analysis and thermal calculations for underground vault-type storage and eventual disposal of DPCs. The reader is referred to the earlier reports (Hardin et al. 2011, 2012, 2013; Hardin and Voegele 2013) for contextual information on DPC direct disposal alternatives.
DEFF Research Database (Denmark)
Zhang, Wei; Neo, Suat Peng; Gunaratne, Jayantha
2015-01-01
The high proliferation rate of cancer cells, together with environmental factors such as hypoxia and nutrient deprivation can cause Endoplasmic Reticulum (ER) stress. The protein kinase PERK is an essential mediator in one of the three ER stress response pathways. Genetic and pharmacological...... inhibition of PERK has been reported to limit tumor growth in xenograft models. Here we provide evidence that inactive PERK interacts with the nuclear pore-associated Vault complex protein and that this compromises Vault-mediated nuclear transport of PTEN. Pharmacological inhibition of PERK under ER stress...... results is abnormal sequestration of the Vault complex, leading to increased cytoplasmic PTEN activity and lower AKT activation. As the PI3K/PTEN/AKT pathway is crucial for many aspects of cell growth and survival, this unexpected effect of PERK inhibitors on AKT activity may have implications...
Geometry, rigidity, and group actions
Farb, Benson; Zimmer, Robert J
2011-01-01
The study of group actions is more than a hundred years old but remains to this day a vibrant and widely studied topic in a variety of mathematic fields. A central development in the last fifty years is the phenomenon of rigidity, whereby one can classify actions of certain groups, such as lattices in semi-simple Lie groups. This provides a way to classify all possible symmetries of important spaces and all spaces admitting given symmetries. Paradigmatic results can be found in the seminal work of George Mostow, Gergory Margulis, and Robert J. Zimmer, among others.The p
Wage rigidity and job creation
Christian Haefke; Marcus Sonntag; Thijs van Rens
2007-01-01
Recent research in macroeconomics emphasizes the role of wage rigidity in accounting for the volatility of unemployment fluctuations. We use worker-level data from the CPS to measure the sensitivity of wages of newly hired workers to changes in aggregate labor market conditions. The wage of new hires, unlike the aggregate wage, is volatile and responds almost one-to-one to changes in labor productivity. We conclude that there is little evidence for wage stickiness in the data. We also show, h...
Wage Rigidity and Job Creation
Haefke, Christian; Sonntag, Marcus; Rens, Thijs van
2012-01-01
Recent research in macroeconomics emphasizes the role of wage rigidity in accounting for the volatility of unemployment fluctuations. We use worker-level data from the CPS to measure the sensitivity of wages of newly hired workers to changes in aggregate labor market conditions. The wage of new hires, unlike the aggregate wage, is volatile and responds almost one-to-one to changes in labor productivity. We conclude that there is little evidence for wage stickiness in the data. We also show, h...
Wage Rigidity and Job Creation
Christian Haefke; Marcus Sonntag; Thijs van Rens
2012-01-01
Recent research in macroeconomics emphasizes the role of wage rigidity in ac- counting for the volatility of unemployment fluctuations. We use worker-level data from the CPS to measure the sensitivity of wages of newly hired workers to changes in aggregate labor market conditions. The wage of new hires, unlike the aggregate wage, is volatile and responds almost one-to-one to changes in labor productivity. We conclude that there is little evidence for wage stickiness in the data. We also show,...
Lötsch, Daniela; Steiner, Elisabeth; Holzmann, Klaus; Spiegl-Kreinecker, Sabine; Pirker, Christine; Hlavaty, Juraj; Petznek, Helga; Hegedus, Balazs; Garay, Tamas; Mohr, Thomas; Sommergruber, Wolfgang; Grusch, Michael; Berger, Walter
2013-11-01
Despite their ubiquitous expression and high conservation during evolution, precise cellular functions of vault ribonucleoparticles, mainly built of multiple major vault protein (MVP) copies, are still enigmatic. With regard to cancer, vaults were shown to be upregulated during drug resistance development as well as malignant transformation and progression. Such in a previous study we demonstrated that human astrocytic brain tumours including glioblastoma are generally high in vault levels while MVP expression in normal brain is comparably low. However a direct contribution to the malignant phenotype in general and that of glioblastoma in particular has not been established so far. Thus we address the questions whether MVP itself has a pro-tumorigenic function in glioblastoma. Based on a large tissue collection, we re-confirm strong MVP expression in gliomas as compared to healthy brain. Further, the impact of MVP on human glioblastoma aggressiveness was analysed by using gene transfection, siRNA knock-down and dominant-negative genetic approaches. Our results demonstrate that MVP/vaults significantly support migratory and invasive competence as well as starvation resistance of glioma cells in vitro and in vivo. The enhanced aggressiveness was based on MVP-mediated stabilization of the epidermal growth factor receptor (EGFR)/phosphatidyl-inositol-3-kinase (PI3K) signalling axis. Consequently, MVP overexpression resulted in enhanced growth and brain invasion in human glioblastoma xenograft models. Our study demonstrates, for the first time, that vaults have a tumour-promoting potential by stabilizing EGFR/PI3K-mediated migration and survival pathways in human glioblastoma.
Maddin, Hillary C.; Piekarski, Nadine; Sefton, Elizabeth M.; Hanken, James
2016-08-01
Bones of the cranial vault appear to be highly conserved among tetrapod vertebrates. Moreover, bones identified with the same name are assumed to be evolutionarily homologous. However, recent developmental studies reveal a key difference in the embryonic origin of cranial vault bones between representatives of two amniote lineages, mammals and birds, thereby challenging this view. In the mouse, the frontal is derived from cranial neural crest (CNC) but the parietal is derived from mesoderm, placing the CNC-mesoderm boundary at the suture between these bones. In the chicken, this boundary is located within the frontal. This difference and related data have led several recent authors to suggest that bones of the avian cranial vault are misidentified and should be renamed. To elucidate this apparent conflict, we fate-mapped CNC and mesoderm in axolotl to reveal the contributions of these two embryonic cell populations to the cranial vault in a urodele amphibian. The CNC-mesoderm boundary in axolotl is located between the frontal and parietal bones, as in the mouse but unlike the chicken. If, however, the avian frontal is regarded instead as a fused frontal and parietal (i.e. frontoparietal) and the parietal as a postparietal, then the cranial vault of birds becomes developmentally and topologically congruent with those of urodeles and mammals. This alternative hypothesis of cranial vault homology is also phylogenetically consistent with data from the tetrapod fossil record, where frontal, parietal and postparietal bones are present in stem lineages of all extant taxa, including birds. It further implies that a postparietal may be present in most non-avian archosaurs, but fused to the parietal or supraoccipital as in many extant mammals.
改进的可撤销指纹Fuzzy Vault方案%Improved cancelable fingerprint fuzzy vault system
Institute of Scientific and Technical Information of China (English)
张镕麟; 刘而云; 赵恒; 庞辽军
2011-01-01
Fuzzy vault has been widely applied in biometric encryption domain for key binding, suitable for set feature representation, such as minutiae set of fingerprint image. However, with the real minutia points contained in vault, fuzzy vault is suffered from cross matching problem, which makes attackers easily obtain real minutia information from multiple vault templates and threatens user privacy and secret key security. In this paper, an improved cancelable fuzzy vault scheme is proposed, in which an one-way function based on password is constructed to transform original minutia information and then the transformed minutiae are fed to fuzzy vault system. The attackers can not obtain the original minutia features even though multiple vaults are at hand, and the users can reissue a new vault template by changing password. Experimental results on FVC2002 DB2 show that the proposed method can effectively reduce the hidden troubles and increase security of system.%Fuzzy Vault系统是生物特征加密(Biometric Encryption,BE)领域中广泛应用的密钥绑定框架,适用于集合特征(例如指纹细节点)与密钥的绑定.然而,Vault模板中包含了真实指纹细节点特征,攻击者可以从多个发布的Vault模板中获取真实指纹信息,因而严重威胁到用户的隐私和密钥安全.笔者提出一种改进的可撤销指纹Fuzzy Vault方案.首先,基于口令构造一个不可逆变换函数,应用该变换函数对细节点特征进行变换,然后使用变换后的细节点输入Fuzzy Vault系统.攻击者即使得到多个应用系统上的Vault也不能获得原始指纹细节点特征,且用户可以通过随时更换口令来发布新的Vault模板.在FVC2002 DB2上的实验表明,所提出的方案能有效降低交叉匹配带来的安全隐患,提高系统安全性.
Directory of Open Access Journals (Sweden)
Marco Giorgio Bevilacqua
2016-03-01
Full Text Available In the field of documentation and preservation of cultural heritage, there is keen interest in 3D metric viewing and rendering of architecture for both formal appearance and color. On the other hand, operative steps of restoration interventions still require full-scale, 2D metric surface representations. The transition from 3D to 2D representation, with the related geometric transformations, has not yet been fully formalized for planar development of frescoed vaults. Methodologies proposed so far on this subject provide transitioning from point cloud models to ideal mathematical surfaces and projecting textures using software tools. The methodology used for geometry and texture development in the present work does not require any dedicated software. The different processing steps can be individually checked for any error introduced, which can be then quantified. A direct accuracy check of the planar development of the frescoed surface has been carried out by qualified restorers, yielding a result of 3 mm. The proposed methodology, although requiring further studies to improve automation of the different processing steps, allowed extracting 2D drafts fully usable by operators restoring the vault frescoes.
A statistical method for passive gamma ray tomography of nuclear waste vaults
Energy Technology Data Exchange (ETDEWEB)
Cattle, Brian A. [Nexia Solutions Limited, Hinton House, Risley, Warrington WA3 6AS (United Kingdom)]. E-mail: brian.a.cattle@nexiasolutions.com; West, Robert M. [Nexia Solutions University Research Alliance, University of Leeds, Leeds LS2 9JT (United Kingdom)
2006-11-15
This paper demonstrates a parameter identification problem encountered in the assay of intermediate-level nuclear waste vaults. A lumped parameter model of the vault contents is employed in which a likely geometry is assumed so as to reduce the number of unknown quantities in the resulting inverse problem. The inverse problem is tackled using Bayesian statistics, and the statistical distributions are sampled using a Markov chain Monte Carlo approach. The Bayesian approach affords flexibility in the specification of prior information: i.e. information that is known in advance of recording any measurements. Two parameterizations of the problem are considered: one involving five parameters and the other involving three parameters. It is shown that in order to obtain a satisfactory solution to the five-parameter problem a very specific type of prior information has to be specified, whereas for the three-parameter problem much less specific prior information is required. The inverse problem of identifying the model parameters in both the three-parameter and five-parameter formulations is solved with limited, but quantifiable precision.
Range and Image Based Modelling: a way for Frescoed Vault Texturing Optimization
Caroti, G.; Martínez-Espejo Zaragoza, I.; Piemonte, A.
2015-02-01
In the restoration of the frescoed vaults it is not only important to know the geometric shape of the painted surface, but it is essential to document its chromatic characterization and conservation status. The new techniques of range-based and image-based modelling, each with its limitations and advantages, offer a wide range of methods to obtain the geometric shape. In fact, several studies widely document that laser scanning enable obtaining three-dimensional models with high morphological precision. However, the quality level of the colour obtained with built-in laser scanner cameras is not comparable to that obtained for the shape. It is possible to improve the texture quality by means of a dedicated photographic campaign. This procedure, however, requires to calculate the external orientation of each image identifying the control points on it and on the model through a costly step of post processing. With image-based modelling techniques it is possible to obtain models that maintain the colour quality of the original images, but with variable geometric precision, locally lower than the laser scanning model. This paper presents a methodology that uses the camera external orientation parameters calculated by image based modelling techniques to project the same image on the model obtained from the laser scan. This methodology is tested on an Italian mirror (a schifo) frescoed vault. In the paper the different models, the analysis of precision and the efficiency evaluation of proposed methodology are presented.
Cranial vault trauma and selective mortality in medieval to early modern Denmark.
Boldsen, Jesper L; Milner, George R; Weise, Svenja
2015-02-10
To date, no estimates of the long-term effect of cranial vault fractures on the risk of dying have been generated from historical or prehistoric skeletons. Excess mortality provides a perspective on the efficacy of modern treatment, as well as the human cost of cranial injuries largely related to interpersonal violence in past populations. Three medieval to early modern Danish skeletal samples are used to estimate the effect of selective mortality on males with cranial vault injuries who survived long enough for bones to heal. The risk of dying for these men was 6.2 times higher than it was for their uninjured counterparts, estimated through a simulation study based on skeletal observations. That is about twice the increased risk of dying experienced by modern people with traumatic brain injuries. The mortality data indicate the initial trauma was probably often accompanied by brain injury. Although the latter cannot be directly observed in skeletal remains, it can be inferred through the relative risks of dying. The ability to identify the effects of selective mortality in this skeletal sample indicates it must be taken into account in paleopathological research. The problem is analogous to extrapolating from death register data to modern communities, so epidemiological studies based on mortality data have the same inherent possibility of biases as analyses of ancient skeletons.
Cylindrical air flow reversal barrier
Energy Technology Data Exchange (ETDEWEB)
Woznica, C.; Rodziewicz, M.
1988-06-01
Describes an innovative design introduced in the ZMP mine in Zory for quick reversal of ventilation air flow. Geologic mining conditions at the 705 m deep horizon, where the barrier was built, are described. According to the design used until now, a reversal system consisted of safety barriers, ventilation air locks, a ventilation bridge and stopping needed in case of a fire when air flow direction must be reversed. Nine air locks and an expensive concrete ventilation bridge were needed and the air locks had to be operated at 8 points of the region to effect reversal. The new design consists of a 2-storey cylindrical barrier which also fulfills the function of a ventilation bridge. It can be manually or remotely operated by a mechanical or pneumatic system. Tests showed that the new barrier permits immediate air flow reversal while retaining 60% of the original air, which is important in the case of fire and methane hazards. It permits improved seam panelling and splitting of pillars and brings an economy of about 40 million zlotys in construction cost. Design and operation of the barrier is illustrated and ventilation air circulation is explained. 7 figs.
FACTORS INFLUENCING BENDING RIGIDITY OF SUBMERGED VEGETATION
Institute of Scientific and Technical Information of China (English)
WU Long-hua; YANG Xiao-li
2011-01-01
The bending rigidity of submerged vegetation is closely related with vegetative drag force.This work aims at determining the effects of flow conditions and characteristics of vegetation on the bending rigidity of submerged vegetation.Based on the dimensional analysis method,the factors influencing the bending rigidity of individual submerged vegetation were analyzed.The relationship between the relative bending rigidity and its influencing factors was investigated by experimental observation,and a relative bending rigidity expression for submerged vegetation was obtained by means of multiple linear regression method.The results show that the submerged vegetation has three states under different inflow conditions,and the each critical relative bending rigidity of individual submerged vegetation was determined for the different states of submerged vegetation.
Rigid Ideals and Radicals of Ore Extensions
Institute of Scientific and Technical Information of China (English)
Chan Yong Hong; Tai Keun Kwak; S. Tariq Rizvi
2005-01-01
For an endomorphism σ of a ring R, Krempa called σ a rigid endomorphism if aσ(a) = 0 implies a= 0 for a ∈ R. A ring R is called rigid if there exists a rigid endomorphism of R. In this paper, we extend the σ-rigid property of a ring R to an ideal of R. For a σ-ideal Ⅰ of a ring R, we call Ⅰ a σ-rigid ideal if aσ(a) ∈Ⅰ implies a ∈Ⅰ for a ∈ R. We characterize σ-rigid ideals and study related properties. The connections of the prime radical and the upper nil radical of R with the prime radical and the upper nil radical of the Ore extension R[x; σ, δ], respectively, are also investigated.
Institute of Scientific and Technical Information of China (English)
吴林志; Kunio Funami
2002-01-01
The electro-elastic field of the infinite piezoelectric medium with two piezoelectric circular cylindrical inclusions is derived under the antiplane shear stresses and inplane electric fields. The analytical solution is obtained. The proposed method is based upon the use of conformal mapping and the theorem of analytic continuation. From the results obtained, it can be found that the electro-elastic field depends on the material constants of individual phases, the geometric parameters of the system and the applied antiplane shear stresses and electric fields at infinity. In addition, the specific cases when two circular cylindrical inclusions are tangent to each other and they are holes and/or rigid ones, are also studied in this paper.
Torsional vibrations of a cylindrical foundation embedded in a saturated poroelastic half-space
Institute of Scientific and Technical Information of China (English)
Dazhi WU; Lu YU
2015-01-01
Considering the interactions between an embedded foundation and saturated soil, the torsional vibrations of a cylindrical foundation embedded in a saturated poroelastic medium are analyzed in this paper. Both a rigid foundation and an elastic foundation are considered. Assuming both the side surface and the bottom surface of the foundation are perfectly bonded to soil, the reaction torques that the side soil and bottom soil acting on the foundation can be gained from basic dynamic equations of the poroelastic medium. According to the dynamic equilibrium equations of a foundation under harmonic torque, the torsional vibrations of an embedded cylindrical foundation are presented. Besides, the angular amplitude of the foundation, the equivalent stiffness and damping coefficients of the soil are expressed explicitly. Selected examples are presented to investigate the influence of relevant parameters on the torsional vibrations.
Cylindrical-shaped nanotube field effect transistor
Hussain, Muhammad Mustafa
2015-12-29
A cylindrical-shaped nanotube FET may be manufactured on silicon (Si) substrates as a ring etched into a gate stack and filled with semiconductor material. An inner gate electrode couples to a region of the gate stack inside the inner circumference of the ring. An outer gate electrode couples to a region of the gate stack outside the outer circumference of the ring. The multi-gate cylindrical-shaped nanotube FET operates in volume inversion for ring widths below 15 nanometers. The cylindrical-shaped nanotube FET demonstrates better short channel effect (SCE) mitigation and higher performance (I.sub.on/I.sub.off) than conventional transistor devices. The cylindrical-shaped nanotube FET may also be manufactured with higher yields and cheaper costs than conventional transistors.
Rigidity and flexibility of biological networks
Gaspar, Merse E
2012-01-01
The network approach became a widely used tool to understand the behaviour of complex systems in the last decade. We start from a short description of structural rigidity theory. A detailed account on the combinatorial rigidity analysis of protein structures, as well as local flexibility measures of proteins and their applications in explaining allostery and thermostability is given. We also briefly discuss the network aspects of cytoskeletal tensegrity. Finally, we show the importance of the balance between functional flexibility and rigidity in protein-protein interaction, metabolic, gene regulatory and neuronal networks. Our summary raises the possibility that the concepts of flexibility and rigidity can be generalized to all networks.
Rigidizing Inflatable Deployable Dwelling (RIDD) Project
National Aeronautics and Space Administration — By combining thin thermoplastic films, woven Vectran reinforcements, and heat a reliable, deployable, rigidizing space habitat can be created. Although much research...
Multimode interaction in axially excited cylindrical shells
2014-01-01
Cylindrical shells exhibit a dense frequency spectrum, especially near the lowest frequency range. In addition, due to the circumferential symmetry, frequencies occur in pairs. So, in the vicinity of the lowest natural frequencies, several equal or nearly equal frequencies may occur, leading to a complex dynamic behavior. So, the aim of the present work is to investigate the dynamic behavior and stability of cylindrical shells under axial forcing with multiple equal or nearly equal natural fr...
View factors of cylindrical spiral surfaces
Lebedev, Vladimir A.; Solovjov, Vladimir P.
2016-03-01
Analytical expressions are presented for the view factors (radiative configuration factors) associated with the flat right cylindrical spiral surface. Such cylindrical spiral systems are widely applied as electrical resistance heating elements for lighting devices, electronic radio tubes, high-speed gas flow heaters, and other appliances used for scientific, industrial and domestic purposes. Derivation of the view factors is based on the invariant principles and the results presented in Lebedev (2000, 2003,1988) [1-3].
ANALYSIS OF THE DYNAMIC STABILITY OF ELECTRICAL GRADED PIEZOELECTRIC CIRCULAR CYLINDRICAL SHELLS
Institute of Scientific and Technical Information of China (English)
ZhuJunqiang; ShenYapeng; ChenChangqing
2004-01-01
A system of Mathieu Hill equations have been obtained for the dynamic stability analysis of electrical graded piezoelectric circular cylindrical shells subjected to the combined loading of periodic axial compression and radial pressure and electric field. Bolotin's method is then employed to obtain the dynamic instability regions. It is revealed that the piezoelectric effect, the piezoelectric graded effect and the electric field only have minor effect on the unstable region. In contrast, the geometric parameters, the rigidity of constituent materials and the external loading play a dominant role in determining the unstable region.
Deformation characteristics of mechanical expanding of thin-walled cylindrical parts
Institute of Scientific and Technical Information of China (English)
郭宝锋; 聂绍珉; 金淼; 李群; 吴生富
2003-01-01
Mechanical expanding is one of the finishing processes in cylindrical part forming.The distribution of stress and strain shows clearly regional features.FEA simulation and experiments show that the deformation process can be divided into three phases called as rounding phase,expanding phase and unloading phase in turn,in which the main types of deformation are wall bending,circumference elongating and thickness reducing,and spring back respectively.And the longitudinal section can be divided into three portions.expanding region,transition region and rigid region.The plastic deformation occurs regionally in suspended portion.A regional convex in transitional portion is inevitable.
Axisymmetric oscillations of a cylindrical droplet with a moving contact line
Alabuzhev, A. A.
2016-11-01
Forced oscillations of a cylindrical droplet of an inviscid liquid surrounded by another liquid and bounded in the axial direction by rigid planes are investigated. The system is affected by vibrations whose force is directed parallel to the axis of symmetry of the droplet. The velocity of motion of the contact line is proportional to the deviation of the contact angle from the value at which the droplet is in equilibrium. Linear and nonlinear oscillations are considered. The conditions of the occurrence of resonance are determined.
Cylindrical Helix Spline Approximation of Spatial Curves
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
In this paper, we present a new method for approximating spatial curves with a G1 cylindrical helix spline within a prescribed tolerance. We deduce the general formulation of a cylindrical helix,which has 11 freedoms. This means that it needs 11 restrictions to determine a cylindrical helix. Given a spatial parametric curve segment, including the start point and the end point of this segment, the tangent and the principal normal of the start point, we can always find a cylindrical segment to interpolate the given direction and position vectors. In order to approximate the known parametric curve within the prescribed tolerance, we adopt the trial method step by step. First, we must ensure the helix segment to interpolate the given two end points and match the principal normal and tangent of the start point, and then, we can keep the deviation between the cylindrical helix segment and the known curve segment within the prescribed tolerance everywhere. After the first segment had been formed, we can construct the next segment. Circularly, we can construct the G1 cylindrical helix spline to approximate the whole spatial parametric curve within the prescribed tolerance. Several examples are also given to show the efficiency of this method.
Capone, M.; Campi, M.; Catuogno, R.
2015-02-01
This paper is part of a research about ribbed vaults systems in French Gothic Cathedrals. Our goal is to compare some different gothic cathedrals to understand the complex geometry of the ribbed vaults. The survey isn't the main objective but it is the way to verify the theoretical hypotheses about geometric configuration of the flamboyant churches in Paris. The survey method's choice generally depends on the goal; in this case we had to study many churches in a short time, so we chose 3D reconstruction method based on image dense stereo matching. This method allowed us to obtain the necessary information to our study without bringing special equipment, such as the laser scanner. The goal of this paper is to test image matching 3D reconstruction method in relation to some particular study cases and to show the benefits and the troubles. From a methodological point of view this is our workflow: - theoretical study about geometrical configuration of rib vault systems; - 3D model based on theoretical hypothesis about geometric definition of the vaults' form; - 3D model based on image matching 3D reconstruction methods; - comparison between 3D theoretical model and 3D model based on image matching;
Directory of Open Access Journals (Sweden)
Laurent Dortet
2011-08-01
Full Text Available L. monocytogenes is a facultative intracellular bacterium responsible for listeriosis. It is able to invade, survive and replicate in phagocytic and non-phagocytic cells. The infectious process at the cellular level has been extensively studied and many virulence factors have been identified. Yet, the role of InlK, a member of the internalin family specific to L. monocytogenes, remains unknown. Here, we first show using deletion analysis and in vivo infection, that InlK is a bona fide virulence factor, poorly expressed in vitro and well expressed in vivo, and that it is anchored to the bacterial surface by sortase A. We then demonstrate by a yeast two hybrid screen using InlK as a bait, validated by pulldown experiments and immunofluorescence analysis that intracytosolic bacteria via an interaction with the protein InlK interact with the Major Vault Protein (MVP, the main component of cytoplasmic ribonucleoproteic particules named vaults. Although vaults have been implicated in several cellular processes, their role has remained elusive. Our analysis demonstrates that MVP recruitment disguises intracytosolic bacteria from autophagic recognition, leading to an increased survival rate of InlK over-expressing bacteria compared to InlK(- bacteria. Together these results reveal that MVP is hijacked by L. monocytogenes in order to counteract the autophagy process, a finding that could have major implications in deciphering the cellular role of vault particles.
Trocar-guided total tension-free vaginal mesh repair of post-hysterectomy vaginal vault prolapse.
Milani, A.L.; Withagen, M.I.J.; Vierhout, M.E.
2009-01-01
INTRODUCTION AND HYPOTHESIS: The objective of this study was to report 1 year anatomical and functional outcomes of trocar-guided total tension-free vaginal mesh (Prolift) repair for post-hysterectomy vaginal vault prolapse with one continuous piece of polypropylene mesh. METHODS: We conducted a pro
Mattia Preti’s vault in St John’s, Valletta: New light on a complex iconography
DEFF Research Database (Denmark)
Svenningsen, Jesper
2015-01-01
The article aims at casting new light on Mattia Preti’s well-known decoration of the vault of the conventual church of the Knight Hospitallers, now the Co-cathedral of Valletta. To a modern viewer the iconography of the decoration is all but simple. The iconographic scheme, I argue, seeks to clai...
Kim, Da-Hye; Won, Sung-Yoon; Bae, Jung-Hee; Jung, Ui-Won; Park, Dong-Soo; Kim, Hee-Jin; Hu, Kyung-Seok
2014-05-01
The purpose of the present study is to provide useful data that could be applied to various types of periodontal plastic surgery by detailing the topography of the greater palatine artery (GPA), looking in particular at its depth from the palatal masticatory mucosa (PMM) and conducting a morphometric analysis of the palatal vault. Forty-three hemisectioned hard palates from embalmed Korean adult cadavers were used in this study. The morphometry of the palatal vault was analyzed, and then the specimens were decalcified and sectioned. Six parameters were measured using an image-analysis system after performing a standard calibration. In one specimen, the PMM was separated from the hard palate and subjected to a partial Sihler's staining technique, allowing the branching pattern of the GPA to be observed in a new method. The distances between the GPA and the gingival margin, and between the GPA and the cementoenamel junction were greatest at the maxillary second premolar. The shortest vertical distance between the GPA and the PMM decreased gradually as it proceeded anteriorly. The GPA was located deeper in the high-vault group than in the low-vault group. The premolar region should be recommended as the optimal donor site for tissue grafting, and in particular the second premolar region. The maximum size and thickness of tissue that can be harvested from the region were 9.3 mm and 4.0 mm, respectively.
Assessment of thermal performance for the design of a passively-cooled plutonium storage vault
Sanders, Joseph Conway
A passively-cooled plutonium storage vault, rather than one with a safety-qualified, forced-flow cooling system, could save as much as 100 million over the project lifetime. Either configuration must maintain the temperature of the stored plutonium metal, with its significant internal heat generation, below 239 sp circF. Alpha-phase metal, if allowed to exceed this temperature, will transition to beta-phase metal and undergo a volumetric expansion which could rupture the storage container system. An investigation was performed to determine whether a passively-cooled vault is feasible. Significant temperature drops occurred in two regions, both were gas-filled vertical annuli with heat flux boundary conditions on the inner surfaces and fixed temperature boundary conditions on the outer surfaces. The thermal resistance method was employed to evaluate radial heat transfer across each annulus, coupling natural convection, radiation, and conduction. Correlations from Thomas et al and Kulacki et al were used to evaluate the degree of natural convective enhancement. For the helium-filled region between the plutonium metal rod and the container with a characteristic length of 3.9 centimeters and an aspect ratio of 5.6, the Rayleigh number was 800 when the effect of radiation was removed. This resulted in a Nusselt number of 1.8. For the air-filled region between twelve vertically arranged containers and the storage tube with a characteristic length of 5.8 centimeters and an aspect ratio of 78, the Rayleigh number was 5times10sp5. This resulted in a Nusselt number of approximately 4.5, neglecting the effect of radiation. FIDAP 7.62\\copyright$ (Fluid Dynamics Analysis Package) was used to perform multi-dimensional finite element analyses of these regions employing both buoyant and radiative effects. Both simplified and more geometrically complex models were employed, all of which compared favorably to the results using the thermal resistance method. The results of the
[Laparoscopic Y-shaped polypropylene mesh for uterine and vaginal vault prolapse].
Li, Min; Feng, Yichen; Jin, Shaoyan; Yu, Danhua
2013-09-01
To investigate the effectiveness oflaparoscopic Y-shaped polypropylene mesh in the treatment of uterine and vaginal vault prolapse. Between June 2010 and December 2012, 24 patients with uterine and vaginal vault prolapse were treated by laparoscopic pelvic reconstruction (vagina and uterus-sacral fixation) with Y-shaped polypropylene mesh. The age of patients was 35-60 years (mean, 48.6 years). The disease duration was 2-8 years (mean, 5 years). According to the pelvic organ prolapse quatitative (POP-Q) classification by International Continence Society (ICS), 16 cases were classified as uterine prolapsed degree II and 8 cases as degree III; 15 cases were classified as vaginal prolapse degree I, 7 cases as degree II, and 2 cases as degree III. All patients received postoperative follow-up regularly. Subjective evaluation was done based on prolapse quality of life questionnaire (P-QOL), and objective evaluation based on POP-Q classification. All the patients were operated successfully. The operation time was 22-68 minutes (mean, 33 minutes); the blood loss was 30-80 mL (mean, 51 mL); the indwelling urethral catheter remain was 3-7 days (mean, 4 days); and the hospitalization days were 4-9 days (mean, 6.8 days). Twenty-four patients were followed up 3-12 months (mean, 9 months), of whom, 2 were followed up less than 6 months. All patients had normal urination after withdrawal of urethral catheter, and the residual urine volume was in normal range. No patients had mesh erosion and discomfort during sex, vaginal and anal bearing down. The P-QOL scores at 3, 6, and 12 months after operation were significantly improved when compared with the preoperative value (P 0.05). The postoperative POP-Q classification was degree 0 in 19 cases and degree I in 3 cases, and the objective cure rate was 91.7%. No recurrence was found during followup. Laparoscopic Y-shaped polypropylene mesh for treatment of uterine and vaginal vault prolapse is a safe and effective method, especially
Directory of Open Access Journals (Sweden)
Roman Farana
2013-03-01
Full Text Available BACKGROUND: In gymnastics judging, evaluation of routines in their execution is based on form and technique displayed during the performance. A vaulting performance takes a short time and is affected by the quantity of biomechanical variables. The significant relationships between the vault score and specific aspects of the gymnast’s vault should motivate coaches to monitor these variables as a part of training or routine testing. OBJECTIVE: The purpose of the study was to determine the biomechanical variables that are related to a successful performance of Lou Yun vaults performed by top level male gymnasts during the World Cup competition. METHODS: Ten top-level male gymnasts participated in this study. For the 3D kinematic analysis, two digital camcorders with a frame rate of 50 Hz were used. The data was digitized by Simi Motion software. The Hay and Reid method (1988 was used to identify the biomechanical variables that determine the linear motions of the Lou Yun vaults. A correlation analysis was used to establish the relationship between the biomechanical variables and the judges’ scores. The level of statistical significance was determined at the value of p RESULTS: Six out of 24 examined variables showed significant correlations with the scores. A significant correlation was found in the maximum height of the body centre of mass in the second flight phase (r = .68, in the height of centre of mass at mat touchdown (r = .75, in the relative height from table take-off to mat touchdown (r = –.85, in the duration of the table contact phase (r = –.71, in the duration of the second flight phase (r = .62 and in the vertical velocity of body centre of mass at table take-off (r = .70. CONCLUSIONS: The results of the study suggest that a successful execution of Lou Yun vaults and the achievement of a higher score required: to minimize duration of table support phase; to maximize the vertical velocity in the table take-off phase; to
Westengen, Ola T; Jeppson, Simon; Guarino, Luigi
2013-01-01
Ex-situ conservation of crop diversity is a global concern, and the development of an efficient and sustainable conservation system is a historic priority recognized in international law and policy. We assess the completeness of the safety duplication collection in the Svalbard Global Seed Vault with respect to data on the world's ex-situ collections as reported by the Food and Agriculture Organization of the United Nations. Currently, 774,601 samples are deposited at Svalbard by 53 genebanks. We estimate that more than one third of the globally distinct accessions of 156 crop genera stored in genebanks as orthodox seeds are conserved in the Seed Vault. The numbers of safety duplicates of Triticum (wheat), Sorghum (sorghum), Pennisetum (pearl millet), Eleusine (finger millet), Cicer (chickpea) and Lens (lentil) exceed 50% of the estimated numbers of distinct accessions in global ex-situ collections. The number of accessions conserved globally generally reflects importance for food production, but there are significant gaps in the safety collection at Svalbard in some genera of high importance for food security in tropical countries, such as Amaranthus (amaranth), Chenopodium (quinoa), Eragrostis (teff) and Abelmoschus (okra). In the 29 food-crop genera with the largest number of accessions stored globally, an average of 5.5 out of the ten largest collections is already represented in the Seed Vault collection or is covered by existing deposit agreements. The high coverage of ITPGRFA Annex 1 crops and of those crops for which there is a CGIAR mandate in the current Seed Vault collection indicates that existence of international policies and institutions are important determinants for accessions to be safety duplicated at Svalbard. As a back-up site for the global conservation system, the Seed Vault plays not only a practical but also a symbolic role for enhanced integration and cooperation for conservation of crop diversity.
Directory of Open Access Journals (Sweden)
Ola T Westengen
Full Text Available Ex-situ conservation of crop diversity is a global concern, and the development of an efficient and sustainable conservation system is a historic priority recognized in international law and policy. We assess the completeness of the safety duplication collection in the Svalbard Global Seed Vault with respect to data on the world's ex-situ collections as reported by the Food and Agriculture Organization of the United Nations. Currently, 774,601 samples are deposited at Svalbard by 53 genebanks. We estimate that more than one third of the globally distinct accessions of 156 crop genera stored in genebanks as orthodox seeds are conserved in the Seed Vault. The numbers of safety duplicates of Triticum (wheat, Sorghum (sorghum, Pennisetum (pearl millet, Eleusine (finger millet, Cicer (chickpea and Lens (lentil exceed 50% of the estimated numbers of distinct accessions in global ex-situ collections. The number of accessions conserved globally generally reflects importance for food production, but there are significant gaps in the safety collection at Svalbard in some genera of high importance for food security in tropical countries, such as Amaranthus (amaranth, Chenopodium (quinoa, Eragrostis (teff and Abelmoschus (okra. In the 29 food-crop genera with the largest number of accessions stored globally, an average of 5.5 out of the ten largest collections is already represented in the Seed Vault collection or is covered by existing deposit agreements. The high coverage of ITPGRFA Annex 1 crops and of those crops for which there is a CGIAR mandate in the current Seed Vault collection indicates that existence of international policies and institutions are important determinants for accessions to be safety duplicated at Svalbard. As a back-up site for the global conservation system, the Seed Vault plays not only a practical but also a symbolic role for enhanced integration and cooperation for conservation of crop diversity.
Corrosion of copper containers prior to saturation of a nuclear fuel waste disposal vault
Energy Technology Data Exchange (ETDEWEB)
King, F.; Kolar, M
1997-12-01
The buffer material surrounding the containers in a Canadian nuclear fuel waste disposal vault will partially desiccate as a result of the elevated temperature at the container surface. This will lead to a period of corrosion in a moist air atmosphere. Corrosion will either take the form of slow oxidation if the container surface remains dry or aqueous electrochemical corrosion if the surface is wetted by a thin liquid film. The relevant literature is reviewed, from which it is concluded that corrosion should be uniform in nature, except if the surface is wetted, in which case localized corrosion is a possibility. A quantitative analysis of the extent and rate of uniform corrosion during the unsaturated period is presented. Two bounding cases are considered: first, the case of slow oxidation in moist air following either logarithmic or parabolic oxide-growth kinetics and, second, the case of electrochemically based corrosion occurring in a thin liquid film uninhibited by the growth of corrosion products. (author)
Nondestructive Analysis of MET-5 Paint Can at TA35 Building 2 A-Wing Vault
Energy Technology Data Exchange (ETDEWEB)
Desimone, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vo, Duc Ta [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-11-03
In Building 2 A-wing vault MET-5 has some drums and other packages they wanted NEN-1 help identifying nondestructively. Measurements using a mechanically cooled portable high purity germanium HPGe Ortec detective were taken of a paint can container labeled DU-2A to determine if any radioactive material was inside. The HPGe detector measures the gamma rays emitted by radioactive material and displays it as a spectrum. The spectrum is used to identify this radioactive material by using appropriate analysis software and identifying the gamma ray peaks. A paint can container, DU-2A, was analyzed with PeakEasy 4.84 and FRAM 5.2. The FRAM report is shown below. The enrichment is 0.091% U235 and 99.907% U238. This material is depleted uranium. The measurement was performed in the near field and to extract a mass a far field measurement will need to be taken.
Energy Technology Data Exchange (ETDEWEB)
Luey, J.; Li, S.W.
1993-04-01
Testing was initiated in March 1991 and completed in November 1992 to determine the rate at which asphalt is biodegraded by microorganisms native to the Hanford Site soils. The asphalt tested (AR-6000, US Oil, Tacoma, Washington) is to be used in the construction of a diffusion barrier for the Hanford grout vaults. Experiments to determine asphalt biodegradation rates were conducted using three separate test sets. These test sets were initiated in March 1991, January 1992, and June 1992 and ran for periods of 6 months, 11 months, and 6 months, respectively. The experimental method used was one originally developed by Bartha and Pramer (1965), and further refined by Bowerman et al. (1985), that determined the asphalt biodegradation rate through the measurement of carbon dioxide evolved.
Some more Non-arithmetic Rigid groups
Lubotzky, Alexander
2011-01-01
In "Non arithmetic super rigid groups: counter examples to Platonov's conjecture" Bass and Lubotzky gave a counter example to Platonov's conjecture by presenting an example of a linear group with super-rigidity which is not an arithmetic lattice. In this note, a much richer class of such groups is presented with a somewhat simpler proof.
Underground Parking structure built with deep foundations and vault precast elements in Spain
Directory of Open Access Journals (Sweden)
Fernández-Ordóñez, D.
2012-09-01
Full Text Available In many cases the only places available for the construction of a new car park are the existing streets or roads. These streets may also have important or historic buildings very close to the structure, which means that they cannot be disturbed in any way during the construction of the parking structure.
In this particular case, the novelty is that the top deck is solved with a unique structure: a vault that interacts with the pile wall not only for vertical but also for horizontal loads due to the arch mechanism. The construction of the vault is solved as a large precast element of one piece of more than 16 in length and 2.40m in width, which is built in the factory, transported with the help of trucks and erected on site with large cranes.
En muchos casos las únicas localizaciones para construir aparcamientos son las calles o carreteras. Estas calles también suelen tener alrededor importantes edificios históricos muy cercanos a la propia estructura.
En este caso particular la novedad reside en que el forjado superior está resuelto con una estructura especial: una bóveda que interacciona con la pantalla de pilotes no solo en el sentido vertical sino también en el horizontal formando un verdadero mecanismo de arco. La construcción de la bóveda se ha resuelto con grandes elementos prefabricados de una pieza de más de 16m de longitud y de 2,40m de ancho. Se han fabricado en una factoría, transportados y montados en obra con grandes grúas.
Anand, Mallika; Weaver, Amy L.; Fruth, Kristin M.; Gebhart, John B.
2016-01-01
Objectives To determine factors influencing selection of Mayo-McCall culdoplasty (MMC), open abdominal sacrocolpopexy (ASC), or robotic sacrocolpopexy (RSC) for posthysterectomy vaginal vault prolapse. Methods We retrospectively searched for the records of patients undergoing posthysterectomy apical vaginal prolapse surgery between January 1, 2000, and June 30, 2012, at our institution. Baseline characteristics and explicit selection factors were abstracted from the electronic medical records. Factors were compared between groups using χ2 tests for categorical variables, ANOVA for continuous variables, and Kruskal-Wallis tests for ordinal variables. Results Among the 512 patients identified who met inclusion criteria, the MMC group (n=174) had more patients who were older, American Society of Anesthesiologists class 3+ or greater, had anterior vaginal prolapse grade 3+, desired to avoid abdominal surgery, and did not desire a functional vagina. Patients in the ASC (n=237) and RSC (n=101) groups had more failed prolapse surgeries, suspected abdominopelvic pathologic processes, and chronic pain. Advanced prolapse was more frequently cited as an explicit selection factor for ASC than for either MMC or RSC. Conclusions The most common factors that influenced the type of apical vaginal vault prolapse surgery overlapped with characteristics that differed at baseline. In general, MMC was chosen for advanced anterior vaginal prolapse and baseline characteristics that increased surgical risks, ASC for advanced apical prolapse, and ASC or RSC for recurrent prolapse, suspected abdominal pathology, and patients with chronic pain or lifestyles including heavy lifting. Thus, efforts should be made to attempt to control for selection bias when comparing these procedures. PMID:26945273
Analysis of Penetration Model for Geo-Material by Rigid Projectile
Institute of Scientific and Technical Information of China (English)
LI Jianchun; MA Guowei; YU Maohong
2006-01-01
Based on the cylindrical cavity expansion theory,a plastic-damage-elastic model is proposed for the penetration problem of geo-material.In the model,the unified strength criterion (Yu,1991) is adopted as the failure criterion.The distributions of the radial stress and velocity are analyzed.According to the Newton's second law,a series results of the final penetration depth and the impedance load are obtained to different parameter b,when a rigid projectile normally impacts and penetrates a semi-infinite geo-material target with an impact velocity of 300-1 200 m/s.By comparing with the test data available,it appears that the method can be used in analyzing the final depth and the impedance load of a rigid projectile penetrating into a semi-infinite target with different impact velocities.
Are better conductors more rigid?
Eom, Young-Ho; Jeong, Hawoong; Orland, Henri; Yi, Juyeon
2006-10-01
The variation of the bending stiffness of various materials is studied from the point of view of the electronic band characteristics. As far as the electronically generated bending stiffness κe (which we refer to as electro-stiffness) is concerned, the relevant factors are the orbital overlap t, the gap width u between the valence band and the conduction band, and the electron filling fraction γ. A perturbative calculation leads to the approximate expression κe ~ t2/√u2 + t2. This shows that materials with a large overlap and narrow band gap should be stiffer. The electro-stiffness also depends on the electron filling-fraction. We find that κe(γ) <= κe(1/2). These kinds of behavior are confirmed by numerical calculations. In addition, we study the variation in the projected length of flexible molecules under a voltage bias. The nonlinear variation of the bending rigidity is shown to give rise to a length contraction or dilation, depending on the voltage bias.
Energy Technology Data Exchange (ETDEWEB)
J. R. Morton
2000-09-01
From the 1950s, the Vance Road laboratory was the site of extensive nuclear medical research and involved the used of numerous radionuclides. These nuclides were stored in a source vault stored on the first floor of the facility. Nuclear medical research is no longer conducted in this facility, and the source vault was remediated in preparation for converting the area to office space and general use. The Environmental Survey and Site Assessment Program (ESSAP) of ORISE performed a radiological assessment survey of the source vault and its associated miscellaneous building materials and laboratory equipment in preparation for the conversion to general use space.
Leigh, Larry, Jr.
2002-01-01
Inflated cylindrical struts constructed of kapton polyimide film and rigidized with foam have considerable practical application and potential for use as components of inflatable concentrator assemblies, antenna structures and space power systems, Because of their importance, it is of great interest to characterize the dynamic behavior of these components and structures both experimentally and analytically. It is very helpful to take a building-block approach to modeling and understanding inflatable assemblies by first investigating in detail the behavior of the components such as the struts. The foam material used for rigidization of such cylinders has varying modulus, which is a function of different factors, such as density of the foam. Thus, the primary motivation of the tests and analytical modeling efforts was to determine and understand the response of foam-rigidized cylinders for different densities, sizes, and construction methods, In recent years, inflatable structures have been the subject of renewed interest for space applications such as communications antennae, solar thermal propulsion, and space solar power. A major advantage of using inflatable structures in space is that they are extremely lightweight. This makes inflatables a perfect match for solar thermal propulsion because of the low thrust levels available. An obvious second advantage is on-orbit deployability and subsequent space savings in launch configuration. It can be seen that inflatable cylindrical struts and torus are critical components of structural assemblies. In view of this importance, structural dynamic and static behaviors of typical rigidized polyimide struts are investigated in this paper. The paper will focus on the finite element models that were used to model the behavior of the complete solar collector structure, and the results that they provided, as compared to test data.
Thermally-induced shapes of rigid FR-4 electrical laminates
Lyle, Phra Douglas
In the process of a laminate cooling from the curing temperature to room temperature, a substantial level of thermal residual stresses develop. These residual thermal stresses arise due to the mismatch of the thermal expansion coefficient between lamina and between the reinforcing fibers and the matrix resin, generating warpage, or out of plane deformations, when the laminate is not symmetric about the midplane of the composite. Classical lamination theory has been used to predict the warped shape of an asymmetric laminate; this theory suggests that the cooled room temperature shape to be a stable anticlastic or saddle shape. In the 80s, nonlinear theories were developed in order to explain observations for (0/90) sbT cross-ply laminates that cool to a cylindrical shape and to predict the observed phenomena of an occasional "snap through" between two stable cylindrical shapes. Recently, the nonlinear approach has been successfully modified for the analysis of a square angle-ply laminate, allowing an even greater number of laminates to be evaluated. A rigid FR-4 electrical circuit board is a composite laminate that is designed to be symmetrical; however, after cooling from the press cycle or after cooling from other processing thermal excursions, warpage can occur. One potential cause for this warpage can be inadvertently introduced process or material nonuniformities. This investigation develops an FR-4 electrical laminate model that can transform selected material and process variations into input for the mechanical and thermal matrices required in the formulation of both classical lamination and the nonlinear theories. The output is the predicted warpage, for each theory, for each of the selected material and process variations. These warpage outputs are graphically displayed, quantified and compared for the classical lamination theory and for the four recent nonlinear theories. Also, the predicted warpage deformations are stack ranked in order to provide an
Independence-friendly cylindric set algebras
Mann, Allen L
2007-01-01
Independence-friendly logic is a conservative extension of first-order logic that has the same expressive power as existential second-order logic. In her Ph.D. thesis, Dechesne introduces a variant of independence-friendly logic called IFG logic. We attempt to algebraize IFG logic in the same way that Boolean algebra is the algebra of propositional logic and cylindric algebra is the algebra of first-order logic. We define independence-friendly cylindric set algebras and prove two main results. First, every independence-friendly cylindric set algebra over a structure has an underlying Kleene algebra. Moreover, the class of such underlying Kleene algebras generates the variety of all Kleene algebras. Hence the equational theory of the class of Kleene algebras that underly an independence-friendly cylindric set algebra is finitely axiomatizable. Second, every one-dimensional independence-friendly cylindric set algebra over a structure has an underlying monadic Kleene algebra. However, the class of such underlyin...
Cylindrical Bending of Deformable Textile Rectangular Patch Antennas
Directory of Open Access Journals (Sweden)
Freek Boeykens
2012-01-01
Full Text Available Textile patch antennas are well known as basic components for wearable systems that allow communication between a human body and the external world. Due to their flexibility, textile antennas are subjected to bending when worn, causing a variation in resonance frequency and radiation pattern with respect to the flat state in which their nominal design is performed. Hence, it is important for textile antenna engineers to be able to predict these performance parameters as a function of the bending radius. Therefore, we propose a comprehensive analytical model that extends the cylindrical cavity model for conformal rigid patch antennas by incorporating the effects of patch stretching and substrate compression. It allows to predict the resonance frequency and the radiation pattern as a function of the bending radius. Its validity has been verified experimentally. Unlike previous contributions, which concerned only qualitative studies by means of measurements and numerical full-wave simulations, the proposed model offers advantages in terms of physical insight, accuracy, speed, and cost.
Electronic Quantum Confinement in Cylindrical Potential Well
Baltenkov, A S
2016-01-01
The effects of quantum confinement on the momentum distribution of electrons confined within a cylindrical potential well have been analyzed. The motivation is to understand specific features of the momentum distribution of electrons when the electron behavior is completely controlled by the parameters of a non-isotropic potential cavity. It is shown that studying the solutions of the wave equation for an electron confined in a cylindrical potential well offers the possibility to analyze the confinement behavior of an electron executing one- or two-dimensional motion in the three-dimensional space within the framework of the same mathematical model. Some low-lying electronic states with different symmetries have been considered and the corresponding wave functions have been calculated; the behavior of their nodes and their peak positions with respect to the parameters of the cylindrical well has been analyzed. Additionally, the momentum distributions of electrons in these states have been calculated. The limi...
Cylindrical electrochemical cells with a diaphragm seal
Energy Technology Data Exchange (ETDEWEB)
Georgopoulos, P.
1993-07-13
A cylindrical electrochemical cell is described comprising an anode, a cathode and electrolyte contained in a cylindrical container, the container having an open end and a closed end; wherein the open end of the container is sealed with a seal assembly comprising: (a) a disc-shaped seal member, made from an electrically insulative material, having an outer edge wall connected via a base to a centrally located cylindrical hub that defines an orifice; which base has a ventable diaphragm portion and a nonventable diaphragm portion that is thicker than the ventable diaphragm portion; and wherein the ventable diaphragm portion joins the hub at an interface and becomes gradually thicker in the direction away from the interface toward the outer edge wall so that the ventable diaphragm portion is thinnest at the interface; and (b) a current collector extending through the orifice defined by the hub into the cell's interior to contact one of the cell's electrodes.
Cylindrical polarization symmetry for nondestructive nanocharacterization
Zhan, Qiwen
2003-07-01
Recently there is an increasing interest in laser beams with radial symmetry in polarization. Due to the cylindrical symmetry in polarization, these beams have unique focusing properties, which may find wide applications in a variety of nanometer scale applications, including high-resolution metrology, high-density data storage, and multi-functional optical microtool. In this paper, simple method of generating cylindrically polarized beams is presented and their potential applications to nondestructive nano-characterization are discussed. A high resolution surface plasmon microscope and a surface plasmon enhanced apertureless near-field scanning optical microscope are proposed. An automatic scanning microellipsometer that uses the cylindrical symmetry to enhance the signal-to-noise-ratio in high-spatial-resolution ellipsometric measurement will also be presented.
Algorithms for Graph Rigidity and Scene Analysis
DEFF Research Database (Denmark)
Berg, Alex Rune; Jordán, Tibor
2003-01-01
We investigate algorithmic questions and structural problems concerning graph families defined by `edge-counts'. Motivated by recent developments in the unique realization problem of graphs, we give an efficient algorithm to compute the rigid, redundantly rigid, M-connected, and globally rigid...... by showing that 2d-connected bipartite graphs are d-tight. We give a new algorithm for finding a maximal d-sharp subgraph. We also answer a question of Imai and show that finding a maximum size d-sharp subgraph is NP-hard....
Research on cylindrical shell vibration reduction systems
Institute of Scientific and Technical Information of China (English)
XING Xiao-liang; WANG Min-qing
2008-01-01
Longitudinal and horizontal vibration must both be reduced in an effective vibration isolation system. We present a cylindrical shell vibration isolator as a dynamic system composed of four springs and dampers. Vibration is directly produced by the motion of machinery, and more is subsequently generated by harmonic frequencies within their structure. To test the effectiveness of our isolator, we first determined equations for the transmission of vibration from the machine to its cylindrical shell. Damping effects produced by the vibration parameters of our system are then analyzed.
Stability of generic cylindrical thin shell wormholes
Mazharimousavi, S Habib; Amirabi, Z
2014-01-01
We revisit the stability analysis of cylindrical thin shell wormholes which have been studied in literature so far. Our approach is more systematic and in parallel to the method which is used in spherically symmetric thin shell wormholes. The stability condition is summarized as the positivity of the second derivative of an effective potential at the equilibrium radius, i.e. $V^{\\prime \\prime}\\left(a_{0}\\right) >0$. This may serve as the master equation in all stability problems for the cylindrical thin-shell wormholes.
RESONANCE RADIATION OF SUBMERGED INFINITE CYLINDRICAL SHELL
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
The resonance sound radiation from submerged infinite elastic cylindrical shell, excited by internal harmonic line force, is investigated. The shell radiation power is presented in terms of resonant modal radiation derived from resonance radiation theory (RRT). The resonance radiation formulae are derived from classical Rayleigh normal mode solution, which are useful for understanding the mechanism of sound radiation from submerged shells. As an example, numerical calculation of a thin steel cylindrical shell is done by using these two methods. It seems that the results of RRT solutions are in good agreement with that of Rayleigh normal mode solutions.
Static cylindrical symmetry and conformal flatness
Herrera, L; Marcilhacy, G; Santos, N O
2004-01-01
We present the whole set of equations with regularity and matching conditions required for the description of physically meaningful static cylindrically symmmetric distributions of matter, smoothly matched to Levi-Civita vacuum spacetime. It is shown that the conformally flat solution with equal principal stresses represents an incompressible fluid. It is also proved that any conformally flat cylindrically symmetric static source cannot be matched through Darmois conditions to the Levi-Civita spacetime. Further evidence is given that when the Newtonian mass per unit length reaches 1/2 the spacetime has plane symmetry.
POLARON IN CYLINDRICAL AND SPHERICAL QUANTUM DOTS
Directory of Open Access Journals (Sweden)
L.C.Fai
2004-01-01
Full Text Available Polaron states in cylindrical and spherical quantum dots with parabolic confinement potentials are investigated applying the Feynman variational principle. It is observed that for both kinds of quantum dots the polaron energy and mass increase with the increase of Frohlich electron-phonon coupling constant and confinement frequency. In the case of a spherical quantum dot, the polaron energy for the strong coupling is found to be greater than that of a cylindrical quantum dot. The energy and mass are found to be monotonically increasing functions of the coupling constant and the confinement frequency.
Micromagnetic simulations of cylindrical magnetic nanowires
Ivanov, Yurii P.
2015-05-27
This chapter reviews micromagnetic simulations of cylindrical magnetic nanowires and their ordered arrays. It starts with a description of the theoretical background of micromagnetism. The chapter discusses main magnetization reversal modes, domain wall types, and state diagrams in cylindrical nanowires of different types and sizes. The results of the hysteresis process in individual nanowires and nanowire arrays also are presented. Modeling results are compared with experimental ones. The chapter also discusses future trends in nanowire applications in relation to simulations, such as current-driven dynamics, spintronics, and spincaloritronics. The main micromagnetic programs are presented and discussed, together with the corresponding links.
Directory of Open Access Journals (Sweden)
Ferry Kwakkel
2011-12-01
Full Text Available Given a closed Riemannian manifold (M, g, i.e. compact and boundaryless, there is a partition of its tangent bundle TM = ∪iΣi called the focal decomposition of TM. The sets Σi are closely associated to focusing of geodesics of (M, g, i.e. to the situation where there are exactly i geodesic arcs of the same length joining points p and q in M. In this note, we study the topological structure of the focal decomposition of a closed Riemannian manifold and its relation with the metric structure of the manifold. Our main result is that flat n-tori, n > 2, are focally rigid in the sense that if two flat tori are focally equivalent then the tori are isometric up to rescaling. The case n = 2 was considered before by F. Kwakkel.Dada uma variedade Riemanniana (M, g fechada, isto é, compacta e sem bordo, existe uma partição de seu fibrado tangente TM = ∪iΣi chamada decomposição focal de TM. Os conjuntos Σi estão intimamente associados ao modo como focalizam as geodésicas de (M,g, isto é, à situação em que existem exatamente i arcos de geodésica de mesmo comprimento unindo pontos p e q em M. Nesta nota, estudamos a estrutura topológica da decomposição focal de uma variedade Riemanniana fechada e sua relação com a estrutura métrica de M. Nosso principal resultado é que n-toros planos, n > 2, são focalmente rigidos, isto é, se dois toros planos são focalmente equivalentes, então os dois toros são isométricos módulo mudança de escala. O caso n = 2 foi considerado anteriormente por F. Kwakkel.
Analysis of Switched-Rigid Floating Oscillator
Directory of Open Access Journals (Sweden)
Prabhakar R. Marur
2009-01-01
Full Text Available In explicit finite element simulations, a technique called deformable-to-rigid (D2R switching is used routinely to reduce the computation time. Using the D2R option, the deformable parts in the model can be switched to rigid and reverted back to deformable when needed during the analysis. The time of activation of D2R however influences the overall dynamics of the system being analyzed. In this paper, a theoretical basis for the selection of time of rigid switching based on system energy is established. A floating oscillator problem is investigated for this purpose and closed-form analytical expressions are derived for different phases in rigid switching. The analytical expressions are validated by comparing the theoretical results with numerical computations.
Directory of Open Access Journals (Sweden)
Makarova O.V.
2013-10-01
Full Text Available The analysis of the vaults given about the state is conducted feet gymnasts on the different stages of the long-term training. 93 sportswomen of different qualification took part in research. The system of Big foot was used. It is set that on the early stages of the long-term training for gymnasts observed flattening heights of unevenness of navicular bone above the floor. With growth of qualification of sportswomen to avoid development of pathological changes of vaults feet actually not possibly. It is conditioned the rules of competitions to complication of competition compositions and technique of execution of elements of calisthenics. It is marked that appearance of flattening feet requires: corrections in the system of training; introduction of the specially developed methods on the removal of existent deformations; prophylaxis of flat-footedness; strengthening of musculoskeletal system feet.
Directory of Open Access Journals (Sweden)
Bjelić Igor S.
2016-01-01
Full Text Available This work presents the results of an investigation undertaken to determine the level of natural radioactivity in the traditional building materials used for medieval indoor vaulted constructions in the territory of the central Balkan region. Indoor radiation exposure varies appreciably if it comes from the earth building materials, hence the presence of natural radioisotopes of 226Ra, 232Th, and 40K in masonry vaulted constructions was analyzed using gamma ray spectrometry. In addition, the internal health hazard index, the absorbed dose rates and the effective annual doses were calculated. The results were then compared both with the reported data from the previous studies concerning the territory of the Balkan Peninsula, as well as with the worldwide values for the materials of historic buildings. The results obtained from the materials examined in this paper all showed the radioactivity levels below the maximum permitted values. [Projekat Ministarstva nauke Republike Srbije, br. 171007 i br. 43009
Directory of Open Access Journals (Sweden)
V. S. Meenakshi
2010-09-01
Full Text Available Biometric systems are subjected to a variety of attacks. Stored biometric template attack is very severe compared to all other attacks. Providing security to biometric templates is an important issue in building a reliable personal identification system. Multi biometric systems are more resistive towards spoof attacks compared to unibiometric counterpart. Soft biometric are ancillary information about a person. This work provides security and revocability to iris and retinal templates using combined user and soft biometric based password hardened multimodal biometric fuzzy vault. Password hardening provides security and revocability to biometric templates. Eye biometrics namely iris and retina have certain merits compared to fingerprint. Iris and retina capturing cameras can be mounted on a single device to improve user convenience. Security of the vault is measured in terms of min-entropy.
Wang, Fei; Gong, Haoran; Chen, Xi; Chen, C. Q.
2016-01-01
Origami structures enrich the field of mechanical metamaterials with the ability to convert morphologically and systematically between two-dimensional (2D) thin sheets and three-dimensional (3D) spatial structures. In this study, an in-plane design method is proposed to approximate curved surfaces of interest with generalized Miura-ori units. Using this method, two combination types of crease lines are unified in one reprogrammable procedure, generating multiple types of cylindrical structures. Structural completeness conditions of the finite-thickness counterparts to the two types are also proposed. As an example of the design method, the kinematics and elastic properties of an origami-based circular cylindrical shell are analysed. The concept of Poisson’s ratio is extended to the cylindrical structures, demonstrating their auxetic property. An analytical model of rigid plates linked by elastic hinges, consistent with numerical simulations, is employed to describe the mechanical response of the structures. Under particular load patterns, the circular shells display novel mechanical behaviour such as snap-through and limiting folding positions. By analysing the geometry and mechanics of the origami structures, we extend the design space of mechanical metamaterials and provide a basis for their practical applications in science and engineering. PMID:27624892
Wang, Fei; Gong, Haoran; Chen, Xi; Chen, C. Q.
2016-09-01
Origami structures enrich the field of mechanical metamaterials with the ability to convert morphologically and systematically between two-dimensional (2D) thin sheets and three-dimensional (3D) spatial structures. In this study, an in-plane design method is proposed to approximate curved surfaces of interest with generalized Miura-ori units. Using this method, two combination types of crease lines are unified in one reprogrammable procedure, generating multiple types of cylindrical structures. Structural completeness conditions of the finite-thickness counterparts to the two types are also proposed. As an example of the design method, the kinematics and elastic properties of an origami-based circular cylindrical shell are analysed. The concept of Poisson’s ratio is extended to the cylindrical structures, demonstrating their auxetic property. An analytical model of rigid plates linked by elastic hinges, consistent with numerical simulations, is employed to describe the mechanical response of the structures. Under particular load patterns, the circular shells display novel mechanical behaviour such as snap-through and limiting folding positions. By analysing the geometry and mechanics of the origami structures, we extend the design space of mechanical metamaterials and provide a basis for their practical applications in science and engineering.
Wang, Fei; Gong, Haoran; Chen, Xi; Chen, C Q
2016-09-14
Origami structures enrich the field of mechanical metamaterials with the ability to convert morphologically and systematically between two-dimensional (2D) thin sheets and three-dimensional (3D) spatial structures. In this study, an in-plane design method is proposed to approximate curved surfaces of interest with generalized Miura-ori units. Using this method, two combination types of crease lines are unified in one reprogrammable procedure, generating multiple types of cylindrical structures. Structural completeness conditions of the finite-thickness counterparts to the two types are also proposed. As an example of the design method, the kinematics and elastic properties of an origami-based circular cylindrical shell are analysed. The concept of Poisson's ratio is extended to the cylindrical structures, demonstrating their auxetic property. An analytical model of rigid plates linked by elastic hinges, consistent with numerical simulations, is employed to describe the mechanical response of the structures. Under particular load patterns, the circular shells display novel mechanical behaviour such as snap-through and limiting folding positions. By analysing the geometry and mechanics of the origami structures, we extend the design space of mechanical metamaterials and provide a basis for their practical applications in science and engineering.
Public policies targeting labour market rigidities
Andreea Claudia ŞERBAN
2013-01-01
Labour market rigidity becomes an issue of increasing importance under conditions of shocks associated with the economic crisis due to the need to increase the adaptability and responsiveness to them. Thus, labour market policies must be directed towards mitigating rigidities caused by institutional or demographic factors or certain mismatch between demand and supply of education qualifications. This paper highlights the major role of the active labour market policies tar...
Continental glaciation and its potential impact on a used-fuel disposal vault in the Canadian Shield
Energy Technology Data Exchange (ETDEWEB)
Ates, Y.; Bruneau, D.; Ridgway, W.R
1997-09-01
AECL has been assessing the concept of nuclear fuel waste disposal in a vault excavated at a depth ranging between 500 m and 1000 m in a plutonic rock mass of the Canadian Shield. Glaciation is a natural process that has occurred in the past, and is likely to occur in the future, thus causing changes in the loading conditions on the rock mass hosting the disposal vault. Because the rock mass is a natural barrier to the migration of radionuclides, it is important to evaluate its integrity under load changes caused by the glaciation process. Assuming that the magnitude and extent of the future glaciation will be similar to those of the past, we have reviewed published data pertaining to the last continental ice sheet that covered a large area of North America. Estimates have been madefor the magnitude of stresses due to ice sheet loading for a vault located at depths of 500 to 1000 m. These analyses have shown that the uniform loading of a continental ice sheet would reduce the deviatoric stresses in the Canadian Shield, creating more favourable conditions than those existing at the present time, namely, high horizontal stresses. The effects of surface erosion and increase in the in-situ shear stresses have also been examined. Based on the existing data and structural modelling studies, there would be no significant structural effect on a disposal vault located at 1000-m depth in a plutonic rock. At its maximum size, an ice sheet comparable to the Laurentide ice sheet could reactivate the faults and fracture zones along the perimeter areas. Our analyses have been based on fully drained conditions only. At a potential disposal site, it would be important also to consider the potential for excess pore pressure in the analyses. (author)
Energy Technology Data Exchange (ETDEWEB)
Pereira, Antonio [AlbaNova University Center, Stockholm Center of Physics, Astronomy and Biotechnology (Sweden). Dept. of Physics; Sundstroem, Benny [Swedish Nuclear Power Inspectorate, Stockholm (Sweden)
2003-12-01
Radionuclide releases from the near-field for the vaults of the SFR 1 repository are examined in this report. To model those releases we have developed four models, one for each of the vaults; 2BTF, 1BTF, BMA and BLA. The respective codes are based on the finite element method and are called FEMBTF2, FEMBTF1, FEMBMA and FEMBLA, respectively. These codes are two-dimensional representations of the cross sections of the vaults. The different barriers of the vaults have been modelled individually using the physical dimensions of the cross sections. The same conceptual model has been used to estimate the releases from the near-field. This conceptual model is implemented by four different FEM codes that solve the two-dimensional transport equation, e.g. the advective-diffusive-reactive equation that also includes radioactive decay. An interesting property of the codes is that they allow the use of time-dependent properties to represent for instance the evolution of water flow, porosities, distribution coefficients etc. This capability of the code has been used only in some cases because the FEM codes put heavy requirements on the computer's CPU. The nuclides studied here were chosen from a set representing the highest release rates from the near-field obtained by SKB during their project SAFE. Some of the results reported here are somewhat lower than SKBs, other higher. Uncertainties in the conceptual models and differences in the input data are the reasons for the numerical differences. For most cases, the differences between our results and those of SKB should be considered relatively small within present context of near-field calculations.
Using Elimination Theory to construct Rigid Matrices
Kumar, Abhinav; Patankar, Vijay M; N, Jayalal Sarma M
2009-01-01
The rigidity of a matrix A for target rank r is the minimum number of entries of A that must be changed to ensure that the rank of the altered matrix is at most r. Since its introduction by Valiant (1977), rigidity and similar rank-robustness functions of matrices have found numerous applications in circuit complexity, communication complexity, and learning complexity. Almost all nxn matrices over an infinite field have a rigidity of (n-r)^2. It is a long-standing open question to construct infinite families of explicit matrices even with superlinear rigidity when r=Omega(n). In this paper, we construct an infinite family of complex matrices with the largest possible, i.e., (n-r)^2, rigidity. The entries of an nxn matrix in this family are distinct primitive roots of unity of orders roughly exp(n^4 log n). To the best of our knowledge, this is the first family of concrete (but not entirely explicit) matrices having maximal rigidity and a succinct algebraic description. Our construction is based on elimination...
Metastable magnetic domain walls in cylindrical nanowires
Energy Technology Data Exchange (ETDEWEB)
Ferguson, C.A.; MacLaren, D.A.; McVitie, S., E-mail: Stephen.McVitie@glasgow.ac.uk
2015-05-01
The stability of the asymmetric domain wall (ATDW) in soft magnetic cylindrical nanowires and nanotubes is investigated using micromagnetic simulations. Our calculated phase diagram shows that for cylindrical permalloy nanowires, the transverse domain wall (TDW) is the ground state for radii below 20 nm whilst the Bloch point wall (BPW) is favoured in thicker wires. The ATDW stabilises only as a metastable state but with energy close to that of the BPW. Characterisation of the DW spin structures reveals that the ATDW has a vortex-like surface spin state, in contrast to the divergent surface spins of the TDW. This results in lowering of surface charge above the critical radius. For both cylindrical nanotubes and nanowires we find that ATDWs only appear to exist as metastable static states and are particularly suppressed in nanotubes due to an increase in magnetostatic energy. - Highlights: • We simulate the micromagnetic structures of domain walls in cylindrical nanowires. • A phase diagram identifies ground and metastable states. • Asymmetric transverse walls are metastable in nanowires but suppressed in tubes. • Unrolling surface magnetisation aids visualisation of asymmetry and chirality. • We predict experimental discrimination based on magnetic charge distribution.
Cylindrical vortex wake model: right cylinder
DEFF Research Database (Denmark)
Branlard, Emmanuel; Gaunaa, Mac
2015-01-01
to recall results from 1D momentum theory. It is shown that a superposition of concentric cylindrical systems predicts the independence of annuli, which is assumed in blade element theory and stream-tube analyses. A simple example of application for the estimation of the velocity deficit upstream of a wind...
Magnetic guns with cylindrical permanent magnets
DEFF Research Database (Denmark)
Vokoun, David; Beleggia, Marco; Heller, Luděk
2012-01-01
The motion of a cylindrical permanent magnet (projectile) inside a tubular permanent magnet, with both magnets magnetized axially, illustrates nicely the physical principles behind the operation of magnetic guns. The force acting upon the projectile is expressed semi-analytically as derivative...
New photoelectric method for inside cylindricity measurement
Yu, Houyun; Zhao, Zhuanping; Zhao, Ye; Xu, Meijian
2007-12-01
Cylindricity is an important parameter in the evaluation for a cylindraceous workpiece. It has a direct effect on the precision of assembly and rotation. However it is difficult to carry out inside cylindricity measurement for a large workpiece (length: 2~3m, diameter >200mm), in which the spindle's straightness and measuring table's motion error deserve consideration. In this paper, a new error separation method is presented based on the application of precise photoelectric inspecting technique. And the two errors will be directly measured according to the deviation of facula. During the measurement, the workpiece is installed erectly on the base to minimize its distortion. Laser collimation initializes the measuring needle and gives real-time state of the measuring table. Two kinds of coordinates are used for error compensation, i.e. absolute and imaging coordinates. In the end, the least squares cylinder is used to calculate the cylindricity after all point data of each section are modified. Overall structure design and detailed measuring steps are also listed. Thus, the models of error compensation and cylindricity evaluation are obtained. Simulation results prove them correct with a satisfying precision.
Deformation of cylindrical shells under thermal shock
Energy Technology Data Exchange (ETDEWEB)
Aptukov, V.N. (Institut Mekhaniki Sploshnykh Sred, Perm (USSR))
1990-06-01
The deformation and fracture behavior of cylindrical shells under conditions of a nonsymmetric thermal shock is investigated numerically using a two-dimensional formulation. In particular, attention is given to the effect of the shell thickness on the deformation and fracture characteristics. Some computational difficulties associated with the solution of problems of this type are examined. 16 refs.
The double explosive layer cylindrical compaction method
Stuivinga, M.E.C.; Verbeek, H.J.; Carton, E.P.
1999-01-01
The standard cylindrical configuration for shock compaction is useful for the compaction of composite materials which have some plastic behavior. It can also be used to densify hard ceramics up to about 85% of the theoretical density (TMD), when low detonation velocity explosives (2-4 km s-1) are us
A large acceptance cylindrical drift chamber detector
Energy Technology Data Exchange (ETDEWEB)
Ambrose, D.A. [Texas Univ., Austin, TX (United States); Bachman, M.G. [Texas Univ., Austin, TX (United States); Coffey, W.P. [Texas Univ., Austin, TX (United States); Glass, G. [Texas Univ., Austin, TX (United States); McNaughton, K.H. [Texas Univ., Austin, TX (United States); Riley, P.J. [Texas Univ., Austin, TX (United States); Adams, D.L. [Rice University, Houston, TX 77251 (United States); Gaussiran, T.L. [Rice University, Houston, TX 77251 (United States); Hungerford, E.V. [University of Houston, Houston, TX 77204 (United States); Lan, K.A. [University of Houston, Houston, TX 77204 (United States); Johnston, K. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); McNaughton, M.W. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Penttila, S.I. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Supek, I. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
1995-10-01
This paper describes a large acceptance cylindrical drift chamber detector designed and built for the study of the np{yields}pp{pi}{sup -} reaction at neutron beam energies in the range 500-800 MeV. Details of construction, electronics, testing, and detection efficiencies and resolutions are presented. (orig.).
Shear stresses around circular cylindrical openings
Hoogenboom, P.C.J.; Van Weelden, C.; Blom, C.M.B.
2010-01-01
In this paper stress concentrations are studied around circular cylindrical openings or voids in a linear elastic continuum. The loading is such that a uniform shear stress occurs in the continuum, which is disturbed by the opening. The shear stress is in the direction of the centre axis of the open
Antibubbles and fine cylindrical sheets of air
Beilharz, D.
2015-08-14
Drops impacting at low velocities onto a pool surface can stretch out thin hemispherical sheets of air between the drop and the pool. These air sheets can remain intact until they reach submicron thicknesses, at which point they rupture to form a myriad of microbubbles. By impacting a higher-viscosity drop onto a lower-viscosity pool, we have explored new geometries of such air films. In this way we are able to maintain stable air layers which can wrap around the entire drop to form repeatable antibubbles, i.e. spherical air layers bounded by inner and outer liquid masses. Furthermore, for the most viscous drops they enter the pool trailing a viscous thread reaching all the way to the pinch-off nozzle. The air sheet can also wrap around this thread and remain stable over an extended period of time to form a cylindrical air sheet. We study the parameter regime where these structures appear and their subsequent breakup. The stability of these thin cylindrical air sheets is inconsistent with inviscid stability theory, suggesting stabilization by lubrication forces within the submicron air layer. We use interferometry to measure the air-layer thickness versus depth along the cylindrical air sheet and around the drop. The air film is thickest above the equator of the drop, but thinner below the drop and up along the air cylinder. Based on microbubble volumes, the thickness of the cylindrical air layer becomes less than 100 nm before it ruptures.
Improved Fuzzy Vault fingerprint encryption scheme%一种改进的指纹Fuzzy Vault加密方案
Institute of Scientific and Technical Information of China (English)
谭台哲; 章红燕
2012-01-01
In order to overcome the deficiency of the traditional Fuzzy Vault algorithm in the application,this paper proposed an improved Fuzzy Vault algorithm. It mainly adopted a novel polynomial constructor method to realize the cryptographic key and fingerprint minutiae data binding together, and then solved the problem that the matching minutiae number was determined by the length of secret in the traditional Fuzzy Vault algorithm in key decoding phase. The experiment results show that this method further enhances the security and flexibility of the algorithm.%为了克服传统指纹Fuzzy Vault算法在应用上的不足,提出了一种改进的Fuzzy Vault算法.主要采用一种新的多项式构造函数的方法来实现待保护密钥和指纹细节特征点的绑定,进而解决了传统Fuzzy Vault算法中密钥长度决定解码时需要匹配细节点个数的问题.实验结果表明,此方法进一步增强了算法的安全性和灵活性.
Directory of Open Access Journals (Sweden)
Ghulghazaryan G.R.
2011-03-01
Full Text Available The problem of existence of free vibrations of an elastic orthotropic open cylindrical shell (with arbitrary directional curve with free end, when other edges are rigid – clamped is studied. The investigation is carried out for elastic orthotropic shell when bending rigidity is vanishingly small (the moment free shell. The dispersion equations for finding the natural frequencies of vibrations are derived. The calculations were carried out for the shells with directing curve in form of a parabola with different values of curvature and lengths.
Overexpression of the human major vault protein in astrocytic brain tumor cells.
Berger, W; Spiegl-Kreinecker, S; Buchroithner, J; Elbling, L; Pirker, C; Fischer, J; Micksche, M
2001-11-01
Evidence has shown that the major human vault protein (MVP), which is identical to lung resistance-related protein (LRP), may be causally involved in a special type of multidrug resistance (MDR). The purpose of this study was to investigate the expression and cellular localization of MVP in cells derived from brain tumors and other tumors of neuroectodermal origin. Using both established cell lines (n = 22) and primary explants (n = 30), we show that a distinct overexpression of the MVP gene at the mRNA (RT-PCR) and protein (Western blot) levels is a characteristic feature of cells derived from astrocytic brain tumors. Primary cultures obtained from meningioma specimens also expressed high MVP levels, in contrast to neuroblastoma and medulloblastoma cells, which rarely contained detectable amounts of MVP. Normal human astrocytes cultured in vitro expressed MVP, although at low amounts compared with most malignant cell types. Basal MVP expression correlated with resistance against diverse antineoplastic drugs including anthracyclins, cisplatin and etoposide. By Western blot, MVP was also detected in all tumor samples taken from 7 glioma and 3 meningioma patients. Taken together, these data suggest overexpression of MVP as one explanation for the low efficacy of chemotherapeutic treatment of astrocytic brain tumors. Copyright 2001 Wiley-Liss, Inc.
An optimization model and solution for radiation shielding design of radiotherapy treatment vaults.
Newman, Francis; Asadi-Zeydabadi, Masoud
2008-01-01
In radiation shielding design, one is usually faced with a set of conflicting goals that are navigated by an experienced physicist. If one has abundant space, the task is simplified because concrete is relatively inexpensive and will provide adequate shielding for high energy photons and neutrons, when applicable. However, if space is constrained (which is usually the case), the design becomes more difficult since one will likely have to employ combinations of steel, lead, and concrete, or other new materials--each with different properties and costs. Very experienced shielding designers can draw upon previous plans, but they do not know if their design is optimal in any sense. We have constructed a linear program that minimizes the cost of the shielding materials and minimizes the dose at the protection point or the shielding thickness subject to space constraints and to Federal or State regulations regarding the allowable exposure to individuals adjacent to the radiotherapy vault. In spite of what appears to be a simple model, the solution may require iterations of the optimization to arrive at the optimal solution.
Pan, Hong-Chao; Lin, Jin-Fei; Ma, Li-Ping; Shen, Yan-Qin; Schachner, Melitta
2013-01-01
In contrast to mammals, adult zebrafish recover locomotor functions after spinal cord injury (SCI), in part due to axonal regrowth and regeneration permissivity of the central nervous system. Upregulation of major vault protein (MVP) expression after spinal cord injury in the brainstem of the adult zebrafish prompted us to probe for its contribution to recovery after SCI. MVP is a multifunctional protein expressed not only in many types of tumours but also in the nervous system, where its importance for regeneration is, however, unclear. Using an established zebrafish SCI model, we found that MVP mRNA and protein expression levels were increased in ependymal cells in the spinal cord caudal to the lesion site at 6 and 11 days after SCI. Double immunolabelling showed that MVP was co-localised with Islet-1 or tyrosine hydroxylase around the central canal of the spinal cord in sham-injured control fish and injured fish 11 days after surgery. MVP co-localised with the neural stem cell marker nestin in ependymal cells after injury. By using an in vivo morpholino-based knock-down approach, we found that the distance moved by MVP morpholino-treated fish was reduced at 4, 5 and 6 weeks after SCI when compared to fish treated with standard control morpholino. Knock-down of MVP resulted in reduced regrowth of axons from brainstem neurons into the spinal cord caudal to the lesion site. These results indicate that MVP supports locomotor recovery and axonal regrowth after SCI in adult zebrafish.
Characterisation of baroque tin amalgam mirrors of the historical Green Vault in Dresden
Zywitzki, O.; Nedon, W.; Kopte, T.; Modes, T.
2008-07-01
The historical Green Vault, one of Europe’s most sumptuous treasure chambers, has reopened in September 2006 in the Dresden Royal Palace. For the baroque presentation of the artworks the special properties of tin amalgam mirrors are of great importance. A comprehensive analytic characterisation was necessary for restoration and reconstruction. The different original casting glasses were analysed in respect of chemical composition, roughness, waviness and optical properties like chromaticity coordinates and transmittance. The microstructure of the tin amalgam layers were investigated on metallographic cross-sections and by X-ray diffraction. The investigations reveal that the tin amalgam layers are composed of γ-HgSn6-10 phase with a grain size between 5 and 50 μm surrounded by a thin mercury phase with about 2 wt. % tin. However the most important property of the baroque tin amalgam mirrors is a relative low reflectivity of about 59% which is drastically lower than for silver mirrors with a reflectivity of about 96%. According to the characterisation results a suitable glass for reconstruction was selected. The mirror layers were produced by historical tin amalgam technology for the rooms not destroyed by bombarding of Dresden in February 1945. For the completely destroyed Jewel Room pure tin layers were deposited by magnetron sputtering. The results show that this new technology enables an adequate substitute for the original tin amalgam layers.
Evaluation of the latent radiation dose from the activated radionuclides in a cyclotron vault
Kim, Hyunduk; Cho, Gyuseong; Kim, Sun A.; Kang, Bo Sun
2015-02-01
The production of short-lived radioisotopes for the synthesis of radiopharmaceuticals typically takes advantage of a cyclotron that accelerates a proton beam up to a few tens of MeV. The number of cyclotrons has been continuously increasing since the first operation of the MC-50 for the production of radiopharmaceuticals at the Korea Institute of Radiological & Medical Sciences (KIRAMS) in 1986, and currently 35 cyclotrons are under operation throughout the nation. As the number of operating cyclotrons has increased, concerns about radiation safety for the persons who are working at the facilities and dwelling in the vicinity of the facilities are becoming important issues. Radiation that could emit a time-dependent dose was shown to exist in a cyclotron vault after its shutdown. The calculation of the latent radiation dose rate was performed by using the MCNPX and the FISPACT. The calculated results for the activated long-lived radioisotopes in the concrete wall and the structural components of the cyclotron facility were compared with the measured data that were obtained by using gamma-ray spectroscopy with a HPGe detector.
Numerical Simulation of Large Diameter Cylindrical Structure Slamming
Institute of Scientific and Technical Information of China (English)
XU Jing; WANG De-yu
2008-01-01
The water entry of large diameter cylindrical structure is studied by applying numerical simulation method. The processes of different diameter cylindrical structures impacting water with various constant velocities are calculated numerically. Thereafter, analyzed are the distribution of slamming pressure on structure during slamming course and the influence of slamming velocity and cylindrical diameter on slamming process. Furthermore, presented herein is an equation being used to forecast the peak slamming force on a large diameter cylindrical structure.
Encrypted Fuzzy Vault Based on Password%基于口令的加密模糊金库
Institute of Scientific and Technical Information of China (English)
秦彩霞; 游林
2011-01-01
Fuzzy vault has become an important scheme combining biometric technology with cryptography.Its security depends only on the difficulty of identifying the genuine minutiae points from a mass of disordered points and reconstructing a polynomial with the genuine minutiae points.Aiming at higher security of the system,encrypted fuzzy vault scheme was proposed, which encrypted the minutiae points first and then encoded and decoded fuzzy vault using the encrypted minutiae points.Even though an attacker can identify the genuine minutiae points from the disordered points and reconstruct the polynomial with them,he cannot get the key without the correct password.Experimental comparisons with primitive fuzzy vault on FVC2002-DB2 fingerprint database show that the false accept rate (FAR) of encrypted fuzzy vault is reduced from 0.5％ to 0.001％ ,and the genuine accept rate(GAR) is increased from 92.5％ to 93.5％.%模糊金库已成为乍物特征识别技术与密码技术相结合的一个重要方案.其安全性仅是基于在大最无序的特征点中选取正确的细节特征点并利用它们来重建多项式的难度.为了进一步提高系统安全性,提出加密模糊金库方案.先利用口令加密指纹细节特征点,再将加密后的细节特征点应用于模糊金库的加锁和解锁过程中.攻击者即使在大最无序的特征点中选取出了正确的细节特征点并利用它们重建了多项式,没有输入正确口令时,也得不到密钥.在FVC2002-DB2指纹数据库上与原始模糊金库进行了仿真比较.实验结果表明,加密模糊金库的错误接受率(FAR)从0.5%下降为0.001%,正确接收率(GAR)从95%上升到97%.
21 CFR 876.3630 - Penile rigidity implant.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Penile rigidity implant. 876.3630 Section 876.3630...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Prosthetic Devices § 876.3630 Penile rigidity implant. (a) Identification. A penile rigidity implant is a device that consists of a pair of semi-rigid rods implanted in...
49 CFR 178.706 - Standards for rigid plastic IBCs.
2010-10-01
... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for rigid plastic IBCs. 178.706 Section... PACKAGINGS IBC Performance-Oriented Standards § 178.706 Standards for rigid plastic IBCs. (a) The provisions in this section apply to rigid plastic IBCs intended to contain solids or liquids. Rigid plastic...
The rigidity transition in random graphs
Kasiviswanathan, Shiva Prasad; Theran, Louis
2010-01-01
As we add rigid bars between points in the plane, at what point is there a giant (linear-sized) rigid component, which can be rotated and translated, but which has no internal flexibility? If the points are generic, this depends only on the combinatorics of the graph formed by the bars. We show that if this graph is an Erdos-Renyi random graph G(n,c/n), then there exists a sharp threshold for a giant rigid component to emerge. For c c_2, w.h.p. there is a giant rigid component. The constant c_2 \\approx 3.588 is the threshold for 2-orientability, discovered independently by Fernholz and Ramachandran and Cain, Sanders, and Wormald in SODA'07. We also give quantitative bounds on the size of the giant rigid component when it emerges, proving that it spans a (1-o(1))-fraction of the vertices in the (3+2)-core. Informally, the (3+2)-core is maximal induced subgraph obtained by starting from the 3-core and then inductively adding vertices with 2 neighbors in the graph obtained so far.
Flexible implementation of rigid solar cell technologies.
Energy Technology Data Exchange (ETDEWEB)
Hollowell, Andrew E.
2010-08-01
As a source of clean, remote energy, photovoltaic (PV) systems are an important area of research. The majority of solar cells are rigid materials with negligible flexibility. Flexible PV systems possess many advantages, such as being transportable and incorporable on diverse structures. Amorphous silicon and organic PV systems are flexible; however, they lack the efficiency and lifetime of rigid cells. There is also a need for PV systems that are light weight, especially in space and flight applications. We propose a solution to this problem by arranging rigid cells onto a flexible substrate creating efficient, light weight, and flexible devices. To date, we have created a working prototype of our design using the 1.1cm x 1cm Emcore cells. We have achieved a better power to weight ratio than commercially available PowerFilm{reg_sign}, which uses thin film silicon yielding .034W/gram. We have also tested our concept with other types of cells and verified that our methods are able to be adapted to any rigid solar cell technology. This allows us to use the highest efficiency devices despite their physical characteristics. Depending on the cell size we use, we can rival the curvature of most available flexible PV devices. We have shown how the benefits of rigid solar cells can be integrated into flexible applications, allowing performance that surpasses alternative technologies.
Rigidity loss in disordered network materials
Ellenbroek, Wouter G.; Hagh, Varda F.; Kumar, Avishek; Thorpe, M. F.; van Hecke, Martin
Weakly jammed sphere packings show a very peculiar elasticity, with a ratio of compression modulus to shear modulus that diverges as the number of contacts approaches the minimum required for rigidity. Creating artificial isotropic network materials with this property is a challenge: so far, the least elaborate way to generate them is to actually simulate weakly compressed repulsive spheres. The next steps in designing such networks hinge upon a solid understanding of what properties of the sphere-packing derived network are essential for its elasticity. We elucidate the topological aspects of this question by comparing the rigidity transition in these networks to that in other random spring network models, including the common bond-diluted triangular net and a self-stress-free variant of that. We use the pebble game algorithm for identifying rigid clusters in mechanical networks to demonstrate that the marginally rigid state in sphere packings is perfectly isostatic everywhere, and the addition or removal of a single bond creates a globally stressed or globally floppy network, respectively. By contrast, the other classes of random network random networks show a more localized response to addition and removal of bonds, and, correspondingly, a more gradual rigidity transition.
Directory of Open Access Journals (Sweden)
Kochanowicz Andrzej
2016-12-01
Full Text Available The aim of the study was to define the relationship between maximal power of lower limbs, the biomechanics of the forward handspring vault and the score received during a gymnastics competition. The research involved 42 gymnasts aged 9-11 years competing in the Poland’s Junior Championships. The study consisted of three stages: first -estimating the level of indicators of maximal power of lower limbs tested on a force plate during the countermovement jump; second - estimating the level of biomechanical indicators of the front handspring vault. For both mentioned groups of indicators and the score received by gymnasts during the vault, linear correlation analyses were made. The last stage consisted of conducting multiple regression analysis in order to predict the performance level of the front handspring vault. Results showed a positive correlation (0.401, p < 0.05 of lower limbs’ maximal power (1400 ± 502 W with the judges’ score for the front handstand vault (13.38 ± 1.02 points. However, the highest significant (p < 0.001 correlation with the judges’ score was revealed in the angle of the hip joint in the second phase of the flight (196.00 ± 16.64° and the contact time of hands with the vault surface (0.264 ± 0.118 s, where correlation coefficients were: -0.671 and -0.634, respectively. In conclusion, the angles of the hip joint in the second phase of the flight and when the hands touched the vault surface proved to be the most important indicators for the received score.
Variable-focus cylindrical liquid lens array
Zhao, Wu-xiang; Liang, Dong; Zhang, Jie; Liu, Chao; Zang, Shang-fei; Wang, Qiong-hua
2013-06-01
A variable-focus cylindrical liquid lens array based on two transparent liquids of different refractive index is demonstrated. An elastic membrane divides a transparent reservoir into two chambers. The two chambers are filled with liquid 1 and liquid 2, respectively, which are of different refractive index. The micro-clapboards help liquid 1, liquid 2 and the elastic membrane form a cylindrical lens array. Driving these two liquids to flow can change the shape of the elastic membrane as well as the focal length. In this design, the gravity effect of liquid can be overcome. A demo lens array of positive optical power is developed and tested. Moreover, a potential application of the proposed lens array for autostereoscopic 3D displays is emphasized.
Determination of Coil Inductances Cylindrical Iron Nucleus
Directory of Open Access Journals (Sweden)
Azeddine Mazouz
2014-03-01
Full Text Available The paper describes the investigation and development of a structure and performance characteristics of a coil iron nucleus cylindrical (C.I.N.C. The coil iron nucleus cylindrical is a nonlinear electro radio in which the moving of the nucleus in a sense or in other causes change in inductance and can reach extreme values at the superposition of nucleus and coil centers. The variation of the inductance and the degree of freedom of movement of the nucleus can lead to a device with electromechanical conversion The aim of this paper is the determination and visualization of self inductance and mutual of the (C.I.N.C based on geometric dimensions and the displacement of the nucleus.
Ion distributions in plane and cylindrical chambers.
Rosen, R; George, E P
1975-11-01
The ion chamber equations of Thomson include both ion recombination and space-charge terms. Neglecting the space-charge term, an exact solution is obtained for the ion densities across a plane ionization chamber. The method is extended to the cylindrical chamber, and examples are given of the expected ion distributions in both geometries. Current-voltage relationships are derived for both chambers and compared with those of other workers. If the space-charge term is retained, the ion chamber equations for both geometries are not soluble in closed form. The cylindrical chamber is considered and a computer solution is obtained for the ion distributions and current. Comparison with the nonspace-charge solution shows that while there is only a small difference in the current-voltage relationship, a significant difference can occur in the ion concentrations.
Buckling optimisation of sandwich cylindrical panels
Abouhamzeh, M.; Sadighi, M.
2016-06-01
In this paper, the buckling load optimisation is performed on sandwich cylindrical panels. A finite element program is developed in MATLAB to solve the governing differential equations of the global buckling of the structure. In order to find the optimal solution, the genetic algorithm Toolbox in MATLAB is implemented. Verifications are made for both the buckling finite element code and also the results from the genetic algorithm by comparisons to the results available in literature. Sandwich cylindrical panels are optimised for the buckling strength with isotropic or orthotropic cores with different boundary conditions. Results are presented in terms of stacking sequence of fibers in the face sheets and core to face sheet thickness ratio.
Crack problem in a long cylindrical superconductor
Yong, Hua-Dong; Zhou, You-He; Zeng, Jun
2008-12-01
In this work, the general problem of a center crack in a long cylindrical superconductor is studied. The dependence of the stress intensity factor on the parameters, including the crack length and the applied field, is investigated. We presented a simple model in which the effect of the crack on the critical current is taken into account. It is assumed that the crack forms a perfect barrier to the flow of current. The Bean model and the Kim model are considered for the critical state. Based on the complex potential and boundary collocation methods, the stress intensity factor under the magnetic field is obtained for a long cylindrical superconductor containing a central crack. The results show that the crack length and the applied field have significant effects on the fracture behavior of the superconductor.
Surface superconductivity in thin cylindrical Bi nanowire.
Tian, Mingliang; Wang, Jian; Ning, Wei; Mallouk, Thomas E; Chan, Moses H W
2015-03-11
The physical origin and the nature of superconductivity in nanostructured Bi remains puzzling. Here, we report transport measurements of individual cylindrical single-crystal Bi nanowires, 20 and 32 nm in diameter. In contrast to nonsuperconducting Bi nanoribbons with two flat surfaces, cylindrical Bi nanowires show superconductivity below 1.3 K. However, their superconducting critical magnetic fields decrease with their diameter, which is the opposite of the expected behavior for thin superconducting wires. Quasiperiodic oscillations of magnetoresistance were observed in perpendicular fields but were not seen in the parallel orientation. These results can be understood by a model of surface superconductivity with an enhanced surface-to-bulk volume in small diameter wires, where the superconductivity originates from the strained surface states of the nanowires due to the surface curvature-induced stress.
Torsional rigidity of submanifolds with controlled geometry
DEFF Research Database (Denmark)
Hurtado, Ana; Markvorsen, Steen; Palmer, Vicente
2009-01-01
We prove explicit upper and lower bounds for the torsional rigidity of extrinsic domains of submanifolds ^m$ with controlled radial mean curvature in ambient Riemannian manifolds ^n$ with a pole $ and with sectional curvatures bounded from above and from below, respectively. These bounds are given...... in terms of the torsional rigidities of corresponding Schwarz symmetrizations of the domains in warped product model spaces. Our main results are obtained using methods from previously established isoperimetric inequalities, as found in e.g. [MP4] and [MP5]. As in [MP4] we also characterize the geometry...... of those situations in which the bounds for the torsional rigidity are actually attained and study the behavior at infinity of the so-called geometric average of the mean exit time for Brownian motion....
Measuring the Acceleration of a Rigid Body
Directory of Open Access Journals (Sweden)
Peter G. Martin
1998-01-01
Full Text Available Two methods to measure the six-degree-of-freedom acceleration of a point on a rigid body are presented. The first, referred to as the periphery scheme, makes use of three clusters of accelerometers mounted orthogonal to each other and coincident with the axes of the point. One of the clusters consists of the three accelerometers attached to a cube-shaped triaxial angular rate sensor (ARS. The second method, called the compact cube scheme, uses a single 3-accelerometer/ARS cluster that may be mounted anywhere on the rigid body. During impact tests with an instrumented rigid body, both methods produced measurements that were highly correlated near the time of peak acceleration. Whereas the compact cube scheme was more economical and easier to implement, the periphery scheme produced results that were less disrupted by instrument signal errors and noisy environments.
Expansion-free Cylindrically Symmetric Models
Sharif, M
2013-01-01
This paper investigates cylindrically symmetric distribution of an-isotropic fluid under the expansion-free condition, which requires the existence of vacuum cavity within the fluid distribution. We have discussed two family of solutions which further provide two exact models in each family. Some of these solutions satisfy Darmois junction condition while some show the presence of thin shell on both boundary surfaces. We also formulate a relation between the Weyl tensor and energy density.
Rarefied gas flow in a cylindrical annulus
Lo, S. S.; Loyalka, S. K.; Storvick, T. S.
1983-09-01
The Hansen-Morse model of the linearized Wang Chang-Uhlenbeck equation is used to study the thermal transpiration and mechanocaloric effects for rarefied polyatomic gases in a cylindrical annulus, where boundary conditions are characterized by diffuse reflection. Phenomenological coefficients at all degrees of rarefaction are reported for physical parameters that represent helium, hydrogen, carbon dioxide, and air. Comparisons with isothermal flow data are given.
Shock initiated instabilities in underwater cylindrical structures
Gupta, Sachin; Matos, Helio; LeBlanc, James M.; Shukla, Arun
2016-10-01
An experimental investigation to understand the mechanisms of dynamic buckling instability in cylindrical structures due to underwater explosive loadings is conducted. In particular, the effects of initial hydrostatic pressure coupled with a dynamic pressure pulse on the stability of metallic cylindrical shells are evaluated. The experiments are conducted at varying initial hydrostatic pressures, below the critical buckling pressure, to estimate the threshold after which dynamic buckling will initiate. The transient underwater full-field deformations of the structures during shock wave loading are captured using high-speed stereo photography coupled with modified 3-D Digital Image Correlation (DIC) technique. Experimental results show that increasing initial hydrostatic pressure decreases the natural vibration frequency of the structure indicating loss in structural stiffness. DIC measurements reveal that the initial structural excitations primarily consist of axisymmetric vibrations due to symmetrical shock wave loading in the experiments. Following their decay after a few longitudinal reverberations, the primary mode of vibration evolves which continues throughout later in time. At the initial hydrostatic pressures below the threshold value, these vibrations are stable in nature. The analytical solutions for the vibration frequency and the transient response of cylindrical shell are discussed in the article by accounting for both (1) the added mass effect of the surrounding water and (2) the effect of initial stress on the shell imposed by the hydrostatic pressure. The analytical solutions match reasonably well with the experimental vibration frequencies. Later, the transient response of a cylindrical shell subjected to a general underwater pressure wave loading is derived which leads to the analytical prediction of dynamic stability.
Machining Thin-Walled Cylindrical Parts
Cimbak, Joe; Spagnolo, Jim; Kraus, Dan
1988-01-01
Cylindrical walls only few thousandths of inch thick machined accurately and without tears or punctures with aid of beryllium copper mandrel. Chilled so it contracts, then inserted in cylinder. As comes to room temperature, mandrel expands and fits snugly inside cylinder. Will not allow part to slide and provides solid backup to prevent deflection when part machined by grinding wheel. When machining finished, cylinder-and-mandrel assembly inserted in dry ice, mandrel contracts and removed from part.
Cylindric-like algebras and algebraic logic
Ferenczi, Miklós; Németi, István
2013-01-01
Algebraic logic is a subject in the interface between logic, algebra and geometry, it has strong connections with category theory and combinatorics. Tarski’s quest for finding structure in logic leads to cylindric-like algebras as studied in this book, they are among the main players in Tarskian algebraic logic. Cylindric algebra theory can be viewed in many ways: as an algebraic form of definability theory, as a study of higher-dimensional relations, as an enrichment of Boolean Algebra theory, or, as logic in geometric form (“cylindric” in the name refers to geometric aspects). Cylindric-like algebras have a wide range of applications, in, e.g., natural language theory, data-base theory, stochastics, and even in relativity theory. The present volume, consisting of 18 survey papers, intends to give an overview of the main achievements and new research directions in the past 30 years, since the publication of the Henkin-Monk-Tarski monographs. It is dedicated to the memory of Leon Henkin.
Simulation Analysis of Cylindrical Panoramic Image Mosaic
Directory of Open Access Journals (Sweden)
ZHU Ningning
2017-04-01
Full Text Available With the rise of virtual reality (VR technology, panoramic images are used more widely, which obtained by multi-camera stitching and take advantage of homography matrix and image transformation, however, this method will destroy the collinear condition, make it's difficult to 3D reconstruction and other work. This paper proposes a new method for cylindrical panoramic image mosaic, which set the number of mosaic camera, imaging focal length, imaging position and imaging attitude, simulate the mapping process of multi-camera and construct cylindrical imaging equation from 3D points to 2D image based on photogrammetric collinearity equations. This cylindrical imaging equation can not only be used for panoramic stitching, but also be used for precision analysis, test results show: ①this method can be used for panoramic stitching under the condition of multi-camera and incline imaging; ②the accuracy of panoramic stitching is affected by 3 kinds of parameter errors including focus, displacement and rotation angle, in which focus error can be corrected by image resampling, displacement error is closely related to object distance and rotation angle error is affected mainly by the number of cameras.
On Saturnian cosmic ray cutoff rigidities
Sauer, H. H.
1980-03-01
It has been determined that Saturn possesses a relatively pure dipolar magnetic field through magnetometer measurements made by Ness et al. (1979, private comm.) and Smith et al. (1979). The paper briefly outlines the dipole geomagnetic cutoff theory and demonstrates the scaling required for its applicability to energetic particle measurements in the vicinity of Saturn. Since the cutoff rigidity is a function of viewing direction, the effective cutoff rigidity must be determined as an integration over the finite viewing angle of a physical detector.
Generic Rigidity Matroids with Dilworth Truncations
Tanigawa, Shin-ichi
2010-01-01
We prove that the linear matroid that defines generic rigidity of $d$-dimensional body-rod-bar frameworks (i.e., structures consisting of disjoint bodies and rods mutually linked by bars) can be obtained from the union of ${d+1 \\choose 2}$ graphic matroids by applying variants of Dilworth truncation $n_r$ times, where $n_r$ denotes the number of rods. This leads to an alternative proof of Tay's combinatorial characterizations of generic rigidity of rod-bar frameworks and that of identified body-hinge frameworks.
Rigidity Constraints for Large Mesh Deformation
Institute of Scientific and Technical Information of China (English)
Yong Zhao; Xin-Guo Liu; Qun-Sheng Peng; Hu-Jun Bao
2009-01-01
It is a challenging problem of surface-based deformation to avoid apparent volumetric distortions around largely deformed areas. In this paper, we propose a new rigidity constraint for gradient domain mesh deformation to address this problem. Intuitively the proposed constraint can be regarded as several small cubes defined by the mesh vertices through mean value coordinates. The user interactively specifies the cubes in the regions which are prone to volumetric distortions, and the rigidity constraints could make the mesh behave like a solid object during deformation. The experimental results demonstrate that our constraint is intuitive, easy to use and very effective.
Rigid origami vertices: conditions and forcing sets
Directory of Open Access Journals (Sweden)
Zachary Abel
2016-04-01
Full Text Available We develop an intrinsic necessary and sufficient condition for single-vertex origami crease patterns to be able to fold rigidly. We classify such patterns in the case where the creases are pre-assigned to be mountains and valleys as well as in the unassigned case. We also illustrate the utility of this result by applying it to the new concept of minimal forcing sets for rigid origami models, which are the smallest collection of creases that, when folded, will force all the other creases to fold in a prescribed way.
Thin structured rigid body for acoustic absorption
Starkey, T. A.; Smith, J. D.; Hibbins, A. P.; Sambles, J. R.; Rance, H. J.
2017-01-01
We present a thin acoustic metamaterial absorber, comprised of only rigid metal and air, that gives rise to near unity absorption of airborne sound on resonance. This simple, easily fabricated, robust structure comprising a perforated metal plate separated from a rigid wall by a deeply subwavelength channel of air is an ideal candidate for a sound absorbing panel. The strong absorption in the system is attributed to the thermo-viscous losses arising from a sound wave guided between the plate and the wall, defining the subwavelength channel.
Characteristics of Left-Right Spiral Hollow Cylindrical Roller
Institute of Scientific and Technical Information of China (English)
Liming Lu; Qiping Chen; Yujiang Qin
2015-01-01
Based on new rolling⁃sliding compound bearings, the wear between the one⁃way spiral hollow cylindrical roller and the ribs of the inner and outer ring of rolling⁃sliding compound bearings is reduced by innovational structural design. A new left⁃right spiral hollow cylindrical roller is proposed to replace the one⁃way spiral hollow cylindrical roller. The finite element analysis models of ordinary cylindrical rollers, one⁃way spiral hollow cylindrical rollers and left⁃right spiral hollow cylindrical rollers are respectively established by ABAQUS. The axial displacement of their center mass and the stress distribution of left⁃right spiral hollow cylindrical rollers are compared and analyzed. Theoretical study results show that this new left⁃right spiral hollow cylindrical roller not only inherits the advantages of one⁃way spiral hollow cylindrical rollers, but also avoids the axial offset and the serious wear of the one⁃way spiral hollow cylindrical roller. And the theory research conclusion is verified by the experiment. The left⁃right spiral hollow cylindrical roller has the advantages to overcome boundary stress concentration like logarithmic convex roller. The rolling⁃sliding compound bearings equipped with the new rollers can be better to adapt to the impact of vibration load.
The Effect of Duct Level on the Performance of Reactor Vault Cooling System in the PGSFR
Energy Technology Data Exchange (ETDEWEB)
Yeom, Sujin; Ryu, Seung Ho; Kim, Dehee; Lee, Tae-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2015-10-15
Development of the prototype gen-Ⅵ sodium-cooled fast reactor (PGSFR) has been ongoing in Korea Atomic Energy Research Institute (KAERI). A reactor vault cooling system (RVCS), one of passive decay heat removal systems (PDHRS), passively removes core decay heat by chimney effect when severe accidents occur. The air cooling path is located around containment vessel (CV). An air separator which divides the downstream air and the upstream air is installed between CV and the concrete wall. To design the RVCS, key design parameters such as stack height, gap size between the concrete wall and the air separator, gap size between the air separator and the CV, thickness and layer composition of the air separator have to be determined. A duct level is one of these design parameters. It denotes the height of the upstream air path and related to the heat transfer length from CV to air. The duct level should be optimized with considering structural reliability and heat removal performance. Thus, in this paper, the heat removal performance of RVCS is evaluated depends on the duct level using 1D system design code, that is developed by KAERI autonomously, and commercial CFD program for optimum design of RVCS In this paper, the heat removal performance of RVCS is evaluated depends on the duct level using PARS2- LMR code and commercial CFD program for optimum design of RVCS to satisfy both conflicting needs, structural reliability and cooling performance. As a result of PARS2-LMR code analysis, it was observed that the heat removal rate increases as increase of duct level and the geometrical conditions, that satisfy the design limitations, were obtained. To qualitatively observe the trends of local temperature distribution, CFD simulations were conducted and hotspots were observed at the upper region of ducts for the low duct level case.
基于Fuzzy Vault的身份认证%Identity Authentication Based on Fuzzy Vault
Institute of Scientific and Technical Information of China (English)
李芬; 刘泉; 庞辽军; 裴庆祺
2011-01-01
A scheme named strong two-factor authentication was proposed, to resolve the possible issues of digital identity illegally used by attackers.We stored the generated digital certificate and its private key in a smartcard and protected the PIN of the smartcard by fuzzy vault.The security was improved obviously through combining two kinds of factors to prove one's identity.Meanwhile in order to relieve the computational burden of the smartcard, we imported secret sharing.Only when both the information of the smartcard and the fingerprint server are acquired, would the binding PIN of the smartcard be released.This scheme further perfects the authentication of PKI and is suitable for the authentication of high-end users or high safety customers with special requirements.%针对身份认证中可能出现的数字身份被冒用问题,提出了一种强双因子身份认证方案,将生成的数字证书及私钥存储于用户智能卡中,再使用fuzzy vault保护智能卡的PIN.通过组合2种不同条件来证明一个人的身份,安全性有了明显提高.同时为了减轻智能卡的计算负担,引入秘密共享思想,当且仅当用户智能卡和指纹服务器中信息都可得时,才释放其中绑定的智能卡PIN.该方案进一步完善了PKI的安全认证,适用于高端用户或有特殊需要的高安全度客户的身份认证.
Kan, J; Chellamuthu, P; Obraztsova, A; Moore, J E; Nealson, K H
2011-08-01
This study applied culture-dependent and molecular approaches to examine the bacterial communities at corrosion sites at Granite Mountain Record Vault (GMRV) in Utah, USA, with the goal of understanding the role of microbes in these unexpected corrosion events. Samples from corroded steel chunks, rock particles and waters around the corrosion pits were collected for bacterial isolation and molecular analyses. Bacteria cultivated from these sites were identified as members of Alphaproteobacteria, Gammaproteobacteria, Firmicutes and Actinobacteria. In addition, molecular genetic characterization of the communities via nested-polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) indicated the presence of a broad spectrum of bacterial groups, including Alphaproteobacteria, Betaproteobacteria, Deltaproteobacteria, Actinobacteria, Firmicutes and Bacteroidetes. However, neither cultivation nor molecular approaches identified sulfate-reducing bacteria (SRB), the bacteria commonly implicated as causative organisms were found associated with corrosive lesions in a process referred to as microbially influenced corrosion (MIC). The high diversity of bacterial groups at the corrosion sites in comparison with that seen in the source waters suggested to us a role for the microbes in corrosion, perhaps being an expression of a redox-active group of microbes transferring electrons, harvesting energy and producing biomass. The corrosion sites contained highly diverse microbial communities, consistent with the involvement of microbial activities along the redox gradient at corrosion interface. We hypothesize an electron transport model for MIC, involving diverse bacterial groups such as acid-producing bacteria (APB), SRB, sulfur-oxidizing bacteria (SOB), metal-reducing bacteria (MRB) and metal-oxidizing bacteria (MOB). The characterization of micro-organisms that influence metal-concrete corrosion at GMRV has significant implications for corrosion control in high
Argatov, I
2015-01-01
An indentation testing method, which utilizes lateral contact of a long cylindrical indenter, is developed for a thin transversely isotropic incompressible elastic film deposited onto a smooth rigid substrate. It is assumed that the material symmetry plane is orthogonal to the substrate surface, and the film thickness is small compared to the cylinder indenter length. The presented testing methodology is based on a least squares best fit of the first-order asymptotic model to the depth-sensing indentation data for recovering three independent elastic moduli which characterize an incompressible transversely isotropic material. The case of a weakly compressible material, which is important for biological tissues, is also discussed.
Delayed Equation for Charged Rigid Nonrelativistic Ball
Vlasov, A A
2002-01-01
Simple expression for self-force acting on radiating rigid charged ball is derived (Sommerfeld ball). It is shown that appropriate delayed equation of motion has solutions in general differ from that for Sommerfeld sphere - there are no "radiationless" solutions, but there are oscillating without damping solutions though self-force has nonzero value.
Rigid body dynamics on the Poisson torus
Richter, Peter H.
2008-11-01
The theory of rigid body motion with emphasis on the modifications introduced by a Cardan suspension is outlined. The configuration space is no longer SO(3) but a 3-torus; the equivalent of the Poisson sphere, after separation of an angular variable, is a Poisson torus. Iso-energy surfaces and their bifurcations are discussed. A universal Poincaré section method is proposed.
Viscoelasticity of suspensions of long, rigid rods
Dhont, Jan K.G.; Briels, W.J.
2003-01-01
A microscopic theory for the viscoelastic behaviour of suspensions of rigid rods with excluded volume interactions is presented, which is valid in the asymptotic limit of very long and thin rods. Stresses arising from translational and rotational Brownian motion and direct interactions are calculate
The rigid orthogonal Procrustes rotation problem
Ten Berge, JMF
2006-01-01
The problem of rotating a matrix orthogonally to a best least squares fit with another matrix of the same order has a closed-form solution based on a singular value decomposition. The optimal rotation matrix is not necessarily rigid, but may also involve a reflection. In some applications, only rigi
Rigid rod anchored to infinite membrane.
Guo, Kunkun; Qiu, Feng; Zhang, Hongdong; Yang, Yuliang
2005-08-15
We investigate the shape deformation of an infinite membrane anchored by a rigid rod. The density profile of the rod is calculated by the self-consistent-field theory and the shape of the membrane is predicted by the Helfrich membrane elasticity theory [W. Helfrich, Z. Naturforsch. 28c, 693 (1973)]. It is found that the membrane bends away from the rigid rod when the interaction between the rod and the membrane is repulsive or weakly attractive (adsorption). However, the pulled height of the membrane at first increases and then decreases with the increase of the adsorption strength. Compared to a Gaussian chain with the same length, the rigid rod covers much larger area of the membrane, whereas exerts less local entropic pressure on the membrane. An evident gap is found between the membrane and the rigid rod because the membrane's curvature has to be continuous. These behaviors are compared with that of the flexible-polymer-anchored membranes studied by previous Monte Carlo simulations and theoretical analysis. It is straightforward to extend this method to more complicated and real biological systems, such as infinite membrane/multiple chains, protein inclusion, or systems with phase separation.
Quantification of the UPDRS Rigidity Scale.
Patrick, S K; Denington, A A; Gauthier, M J; Gillard, D M; Prochazka, A
2001-03-01
In the clinical setting, parkinsonian rigidity is assessed using subjective rating scales such as that of the Unified Parkinson's Disease Rating System (UPDRS). However, such scales are susceptible to problems of sensitivity and reliability. Here, we evaluate the reliability and validity of a device designed to quantify parkinsonian rigidity at the elbow and the wrist. The method essentially quantifies the clinical examination and employs small sensors to monitor forces and angular displacements imposed by the clinician onto the limb segment distal to the joint being evaluated. Force and displacement data are used to calculate elastic and viscous stiffnesses and their vectorial sum, mechanical impedance. Interexaminer agreement of measures of mechanical impedance in subjects with Parkinson's disease was comparable to that of clinical UPDRS scores. Examiners tended to overrate rigidity on the UPDRS scale during reinforcement manoeuvres. Mechanical impedance was nonlinearly related to UPDRS ratings of rigidity at the elbow and wrist; characterization of such relationships allows interpretation of impedance measurements in terms of the clinical rating scales.
Geometric integrators for stochastic rigid body dynamics
Tretyakov, Mikhail
2016-01-05
Geometric integrators play an important role in simulating dynamical systems on long time intervals with high accuracy. We will illustrate geometric integration ideas within the stochastic context, mostly on examples of stochastic thermostats for rigid body dynamics. The talk will be mainly based on joint recent work with Rusland Davidchak and Tom Ouldridge.
Rigid polyurethane and kenaf core composite foams
Rigid polyurethane foams are valuable in many construction applications. Kenaf is a bast fiber plant where the surface stem skin provides bast fibers whose strength-to-weight ratio competes with glass fiber. The higher volume product of the kenaf core is an under-investigated area in composite appli...
Cracking of open traffic rigid pavement
Directory of Open Access Journals (Sweden)
Niken Chatarina
2017-01-01
Full Text Available The research is done by observing the growth of real structure cracking in Natar, Lampung, Indonesia compared to C. Niken’s et al research and literature study. The rigid pavement was done with open traffic system. There are two main crack types on Natar rigid pavement: cracks cross the road, and cracks spreads on rigid pavement surface. The observation of cracks was analyzed by analyzing material, casting, curing, loading and shrinkage mechanism. The relationship between these analysis and shrinkage mechanism was studied in concrete micro structure. Open traffic make hydration process occur under vibration; therefore, fresh concrete was compressed and tensioned alternately since beginning. High temperature together with compression, cement dissociation, the growth of Ca2+ at very early age leads abnormal swelling. No prevention from outside water movement leads hydration process occur with limited water which caused spreads fine cracks. Limited water improves shrinkage and plastic phase becomes shorter; therefore, rigid pavement can’t accommodate the abnormal swelling and shrinking alternately and creates the spread of cracks. Discontinuing casting the concrete makes both mix under different condition, the first is shrink and the second is swell and creates weak line on the border; so, the cracks appear as cracks across the road.
De Maio, Anna; Natale, Emiliana; Rotondo, Sergio; Di Cosmo, Anna; Faraone-Mennella, Maria Rosaria
2013-09-01
Our previous behavioural, biochemical and immunohistochemical analyses conducted in selected regions (supra/sub oesophageal masses) of the Octopus vulgaris brain detected a cytoplasmic poly-ADP-ribose polymerase (more than 90% of total enzyme activity). The protein was identified as the vault-free form of vault-poly-ADP-ribose polymerase. The present research extends and integrates the biochemical characterization of poly-ADP-ribosylation system, namely, reaction product, i.e., poly-ADP-ribose, and acceptor proteins, in the O. vulgaris brain. Immunochemical analyses evidenced that the sole poly-ADP-ribose acceptor was the octopus cytoskeleton 50-kDa actin. It was present in both free, endogenously poly-ADP-ribosylated form (70kDa) and in complex with V-poly-ADP-ribose polymerase and poly-ADP-ribose (260kDa). The components of this complex, alkali and high salt sensitive, were purified and characterized. The kind and the length of poly-ADP-ribose corresponded to linear chains of 30-35 ADP-ribose units, in accordance with the features of the polymer synthesized by the known vault-poly-ADP-ribose polymerase. In vitro experiments showed that V-poly-ADP-ribose polymerase activity of brain cytoplasmic fraction containing endogenous actin increased upon the addition of commercial actin and was highly reduced by ATP. Anti-actin immunoblot of the mixture in the presence and absence of ATP showed that the poly-ADP-ribosylation of octopus actin is a dynamic process balanced by the ATP-dependent polymerization of the cytoskeleton protein, a fundamental mechanism for synaptic plasticity.
阴道穹窿脱垂的研究进展%Research Progress of Vaginal Vault Prolapse
Institute of Scientific and Technical Information of China (English)
曲路芸
2011-01-01
Pelvic floor dysfunction (PFD) is a common disease among middle and aged women, which includes pelvic organ prolapse (POP) and stress urinary incontinence (SUI). Vaginal vault prolapse is another pattern of manifestation of POP. It s an usual complication of hysterectomy and will occur after 2-13 years. The incidence of the vaginal vault prolapse is about 2%-A5%. It will result in disturbance of urinary system, disorders of rectum and anal, even sexual dysfunction. And it is difficult to handle. With the deep understanding in the study of pelvic anatomy, the reconstruction surgery of vaginal vault prolapse has made further progress. The purpose of this article is to sum up the diagnosis, methods and effects of treatment, complications of vaginal vault prolapse.%盆底功能障碍性疾病(PFD)是中老年妇女的常见病,主要包括盆腔脏器脱垂(POP)和压力性尿失禁(SUI).而阴道穹窿脱垂是POP的一种表现形式,是传统子宫切除术后的常见并发症,多发生于子宫切除术后2~13年,发生率为2%～45%,可导致妇女泌尿系统、肛门、直肠及性功能障碍,严重影响其生活质量.近年来,随着对盆底解剖研究的深入,阴道穹窿脱垂修复重建手术取得突破性进展,治疗效果不断提高.为深入了解导致阴道穹窿脱垂的病因,本研究对其相关风险因素、诊断手段、治疗方式和效果及可能引发的并发症等,进行综述如下.
Yagoda-Biran, G.; Hatzor, Y. H.
2013-12-01
Evidence for seismically induced damage are preserved in historic masonry structures below the Old City of Jerusalem at a site known locally as the 'Western Wall Tunnels' complex, possibly one of the most important tourist attractions in the world. In the tunnels, structures dated to 500 BC and up until modern times have been uncovered by recent archeological excavation. One of the interesting findings is a 100 m long bridge, composed of two rows of barrel vaults, believed to have been constructed during the 3rd century AD to allow easy access to the Temple Mount. In one of the vaults a single masonry block is displaced 7 cm downward with respect to its neighbors (see figure below). Since the damage seems seismically driven, back analysis of the damage with the numerical Discontinuous Deformation Analysis (DDA) method was performed, in order to constrain the peak ground acceleration (PGA) that had caused the damage. First the numerical method used for back analysis was verified with an analytical solution for the case of a rocking monolithic column, then validated with experimental results for site response analysis. The verification and validation prove the DDA is capable of handling dynamic and wave propagation problems. Next, the back analysis was performed. Results of the dynamic numerical simulations suggest that the damage observed at the vault was induced by seismic vibrations that must have taken place before the bridge was buried underground, namely when it was still in service. We find that the PGA required for causing the observed damage was high - between 1.5 and 2 g. The PGA calculated for Jerusalem on the basis of established attenuation relationships for historic earthquakes that struck the region during the relevant time period is about one order of magnitude lower: 0.14 and 0.48 g, for the events that took place at 362 and 746 AD, respectively. This discrepancy is explained by local site effects that must have amplified bedrock ground motions by a
Rigid Spine Syndrome among Children in Oman
Directory of Open Access Journals (Sweden)
Roshan Koul
2015-08-01
Full Text Available Objectives: Rigidity of the spine is common in adults but is rarely observed in children. The aim of this study was to report on rigid spine syndrome (RSS among children in Oman. Methods: Data on children diagnosed with RSS were collected consecutively at presentation between 1996 and 2014 at the Sultan Qaboos University Hospital (SQUH in Muscat, Oman. A diagnosis of RSS was based on the patient’s history, clinical examination, biochemical investigations, electrophysiological findings, neuro-imaging and muscle biopsy. Atrophy of the paraspinal muscles, particularly the erector spinae, was the diagnostic feature; this was noted using magnetic resonance imaging of the spine. Children with disease onset in the paraspinal muscles were labelled as having primary RSS or rigid spinal muscular dystrophy. Secondary RSS was classified as RSS due to the late involvement of other muscle diseases. Results: Over the 18-year period, 12 children were included in the study, with a maleto- female ratio of 9:3. A total of 10 children were found to have primary RSS or rigid spinal muscular dystrophy syndrome while two had secondary RSS. Onset of the disease ranged from birth to 18 months of age. A family history was noted, with two siblings from one family and three siblings from another (n = 5. On examination, children with primary RSS had typical features of severe spine rigidity at onset, with the rest of the neurological examination being normal. Conclusion: RSS is a rare disease with only 12 reported cases found at SQUH during the study period. Cases of primary RSS should be differentiated from the secondary type.
Barysh, A E; Kozyrev, S A
2015-02-01
Results of surgical treatment of 34 patients, suffering cervical vertebral column traumas and diseases, are analyzed. In all the patients bisegmental anterior interbody spondylodesis was conducted, using cervical rigid plates and vertical cylindrical net implants. The existing and newly obtained information about changes in the radiological indices dynamics while the method application by its authors is presented. The interbody synostosis was achieved in 82.4% patients in 1 yr after the operation. The complications rate while the implants application have constituted 23.3%, and the total rate of complications--29.1%.
Coupling Frequency of the Liquid Sloshing in a Cylindrical Tank with a Flexible Baffle
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
The coupling oscillation of a liquid in a cylindrical tank with an elastic slosh baffle is investigated. Free surface conditions are considered in the study. The complexity of the coupled boundary-value problem for the liquid and elastic damping spacer results in significant analytical difficulties. Two different velocity potential functions are respectively used in the liquid domain above, or below the damping spacer. A coupled frequency equation is obtained by using the pair of velocity potential functions. The numerical and theoretical analysis show that the natural frequency changes according to the location and stiffness of the spacer. Results indicate that the frequency coupling between damping spacer and sloshing liquid is obvious near the free liquid surface. It is shown that the coupling frequency increases with the increase of damping baffle rigidity.
The two-body problem of a pseudo-rigid body and a rigid sphere
DEFF Research Database (Denmark)
Kristiansen, Kristian Uldall; Vereshchagin, M.; Gózdziewski, K.;
2012-01-01
n this paper we consider the two-body problem of a spherical pseudo-rigid body and a rigid sphere. Due to the rotational and "re-labelling" symmetries, the system is shown to possess conservation of angular momentum and circulation. We follow a reduction procedure similar to that undertaken...... in the study of the two-body problem of a rigid body and a sphere so that the computed reduced non-canonical Hamiltonian takes a similar form. We then consider relative equilibria and show that the notions of locally central and planar equilibria coincide. Finally, we show that Riemann's theorem on pseudo......-rigid bodies has an extension to this system for planar relative equilibria....
Antiplane SH-deformations near a surface rigid foundation above a subsurface rigid circular tunnel
Lee, V. W.; Manoogian, M. E.; Chen, S.
2002-06-01
The problem on the dynamic response of a rigid embedded foundation in the presence of an underground rigid tunnel and subjected to excitation of incident anti-plane SH waves is analyzed. By using the exact analytical solution for the two-dimensional SH-wave propagation in and around both the surface rigid foundation and subsurface rigid tunnel, those aspects of the resulting ground motions that are of special interest and importance for seismic resistant design in earthquake analyses have been examined. The computed amplitudes of the resulting periodic ground motions display a very complicated wave-interference between the surface foundation and underground tunnel that lead to observed standing wave patterns, together with abrupt changes in the wave amplitudes and large amplification of the incident motions.
DEFF Research Database (Denmark)
Orozco Santillan, Arturo; Cutanda Henríquez, Vicente
2008-01-01
devices. It is shown that the use of the Boltzmann-Ehrenfest principle of adiabatic invariance allows the derivation of an expression for the resonance frequency shift in a simpler and more direct way than a method based on a Green’s function reported in the literature. The position of the sphere can...
Badriev, I. B.; Makarov, M. V.; Paimuhin, V. N.
2016-11-01
We study the problems of deformation mechanics of sandwich constructions with taking into account the interaction with the contour reinforcing rods. To derive the basic equations of equilibrium, static boundary conditions for the shell and reinforcing rods, as well as conditions of the kinematic conjugation the carrier layers with a core, the carrier layers and a core with reinforcing rods we use a generalized variational Lagrange principle. We reduce the boundary value problem on the to the integral-algebraic system of Volterra equations of the second kind. To approximate the obtained integral equations of Volterra type a collocation method with Gaussian nodes and a method for constructing the integrating matrices are proposed. For the numerical realization of the proposed methods we have developed a software package. Numerical calculations were performed. Analyze the results of numerical experiments is carried out.
Near real-time measurement of forces applied by an optical trap to a rigid cylindrical object
Glaser, Joseph; Hoeprich, David; Resnick, Andrew
2014-07-01
An automated data acquisition and processing system is established to measure the force applied by an optical trap to an object of unknown composition in real time. Optical traps have been in use for the past 40 years to manipulate microscopic particles, but the magnitude of applied force is often unknown and requires extensive instrument characterization. Measuring or calculating the force applied by an optical trap to nonspherical particles presents additional difficulties which are also overcome with our system. Extensive experiments and measurements using well-characterized objects were performed to verify the system performance.
Energy Technology Data Exchange (ETDEWEB)
Bennett, R.D.; Miller, W.O.; Warriner, J.B.; Malone, P.G.; McAneny, C.C.
1984-04-01
The study reported herein contains the results of Task 1 of a four-task study entitled Criteria for Evaluating Engineered Facilities. The overall objective of this study is to ensure that the criteria needed to evaluate five alternative low-level radioactive waste (LLW) disposal methods are available to the Nuclear Regulatory Commission (NRC) and the Agreement States. The alternative methods considered are belowground vaults, aboveground vaults, earth mounded concrete bunkers, mined cavities, and augered holes. Each of these alternatives is either being used by other countries for low-level radioactive waste (LLW) disposal or is being considered by other countries or US agencies. In this report the performance requirements are listed, each alternative is described, the experience gained with its use is discussed, and the performance capabilities of each method are addressed. Next, the existing 10 CFR Part 61 Subpart D criteria with respect to paragraphs 61.50 through 61.53, pertaining to site suitability, design, operations and closure, and monitoring are assessed for applicability to evaluation of each alternative. Preliminary conclusions and recommendations are offered on each method's suitability as an LLW disposal alternative, the applicability of the criteria, and the need for supplemental or modified criteria.
Radiation of sound from unflanged cylindrical ducts
Hartharan, S. L.; Bayliss, A.
1983-01-01
Calculations of sound radiated from unflanged cylindrical ducts are presented. The numerical simulation models the problem of an aero-engine inlet. The time dependent linearized Euler equations are solved from a state of rest until a harmonic solution is attained. A fourth order accurate finite difference scheme is used and solutions are obtained from a fully vectorized Cyber-203 computer program. Cases of both plane waves and spin modes are treated. Spin modes model the sound generated by a turbofan engine. Boundary conditions for both plane waves and spin modes are treated. Solutions obtained are compared with experiments conducted at NASA Langley Research Center.
Free vibrations of circular cylindrical shells
Armenàkas, Anthony E; Herrmann, George
1969-01-01
Free Vibrations of Circular Cylindrical Shells deals with thin-walled structures that undergo dynamic loads application, thereby resulting in some vibrations. Part I discusses the treatment of problems associated with the propagation of plane harmonic waves in a hollow circular cylinder. In such search for solutions, the text employs the framework of the three-dimensional theory of elasticity. The text explains the use of tables of natural frequencies and graphs of representative mode shapes of harmonic elastic waves bounding in an infinitely long isotropic hollow cylinder. The tables are
Kaluza-Klein Magnetized Cylindrical Wormhole
Hashemi, S Sedigheh
2015-01-01
A new exact vacuum solution in five dimensions, which describes a magnetized cylindrical wormhole in $3+1$ dimensions is presented. The magnetic field lines are stretched along the wormhole throat and are concentrated near to it. We study the motion of neutral and charged test particles under the influence of the magnetized wormhole. The effective potential for a neutral test particle around and across the magnetized wormhole has a repulsive character. The total magnetic flux on either side of the wormhole is obtained. We present analytic expressions which show regions in which the null energy condition is violated.
Cellular Cell Bifurcation of Cylindrical Detonations
Institute of Scientific and Technical Information of China (English)
HAN Gui-Lai; JIANG Zong-Lin; WANG Chun; ZHANG Fan
2008-01-01
Cellular cell pattern evolution of cylindrically-diverging detonations is numerically simulated successfully by solving two-dimensional Euler equations implemented with an improved two-step chemical kinetic model. From the simulation, three cell bifurcation modes are observed during the evolution and referred to as concave front focusing, kinked and wrinkled wave front instability, and self-merging of cellular cells. Numerical research demonstrates that the wave front expansion resulted from detonation front diverging plays a major role in the cellular cell bifurcation, which can disturb the nonlinearly self-sustained mechanism of detonations and finally lead to cell bifurcations.
A cylindrical furnace for absorption spectral studies
Indian Academy of Sciences (India)
R Venkatasubramanian
2001-06-01
A cylindrical furnace with three heating zones, capable of providing a temperature of 1100°C, has been fabricated to enable recording of absorption spectra of high temperature species. The temperature of the furnace can be controlled to ± 1°C of the set temperature. The salient feature of this furnace is that the material being heated can be prevented from depositing on the windows of the absorption cell by maintaining a higher temperature at both the ends of the absorption cell.
Cylindrical metamaterial-based subwavelength antenna
DEFF Research Database (Denmark)
Erentok, Aycan; Kim, Oleksiy S.; Arslanagic, Samel
2009-01-01
A subwavelength monopole antenna radiating in the presence of a truncated cylindrical shell, which has a capped top face and is made of a negative permittivity metamaterial, is analyzed numerically by a method of moments for the volume-surface integral equation oil the one hand, and a finite...... element method on the other hand. It is shown that a center-fed truncated cylinder, in contrast to an infinite cylinder, provides subwavelength resonances, thus suggesting the possibility, of having a subwavelength antenna system....
OPTIMAL THICKNESS OF A CYLINDRICAL SHELL
Directory of Open Access Journals (Sweden)
Paul Ziemann
2015-01-01
Full Text Available In this paper an optimization problem for a cylindrical shell is discussed. The aim is to look for an optimal thickness of a shell to minimize the deformation under an applied external force. As a side condition, the volume of the shell has to stay constant during the optimization process. The deflection is calculated using an approach from shell theory. The resulting control-to-state operator is investigated analytically and a corresponding optimal control problem is formulated. Moreover, necessary conditions for an optimal solution are stated and numerical solutions are presented for different examples.
Inimluud Mihkli kiriku võlvidelt / Human remains on the vaulted ceiling of Mihkli Church
Directory of Open Access Journals (Sweden)
Martin Malve
2012-01-01
Full Text Available Altogether 4029 human bones or their fragments from the C 13th–18th were gathered and analysed from soil on the vaults of Mihkli (St Michael’s Church in western Estonia during the rescue works in 2011 (photo 1. Ribs and vertebrae formed the majority of bones, but wholly preserved long bones and other larger bones, as well as, hand and foot bones that are quite typical among mixed human remains were almost absent in this case. Therefore, it can be concluded that during the earthworks larger bones were taken from the soil. The minimum number of adults was determined by the ribs of the right side. Only the ribs with preserved heads (figure 1 were used in calculations. The rib fragments indicate approximately 60 adults among the assorted bones. Judging by the radius, there were at least 16 children among the bone assemblage. Scarceness of children in the Mihkli church can be the result of poor preservation, smallness and fragility of their bones, but the possibility that subadult (child and juvenile burials were fewer in the destroyed part of the churchyard cannot be ruled out.Pathological analysis of the osteological material ascertained several diseases and traumas, the most common pathologies being connected to ageing, for example, wearing of joints (Osteoarthrosis. Various diseases related to degeneration of the spine were present – spondylosis, spondyloarthrosis and osteochondrosis. Compression fractures (fractura compressiva and Schmorl´s nodes (nodi Schmorl indicated strenuous physical activity and/or traumas. Dental diseases included caries (photo 2, alveolar reduction, hypoplasia and tooth abscesses. Several upper and lower jaws showed traces of ante mortem lost teeth (photo 3. In one case a canine of the right mandible of an adult man (age 45 + years had formed but had not erupted (photo 4.Various healed fractures of ribs and limb bones formed the bulk of traumas detected on the bones. Three right ribs had fractures in a stage of
Measurement of neutron dose equivalent outside and inside of the treatment vault of GRID therapy
Energy Technology Data Exchange (ETDEWEB)
Wang, Xudong; Charlton, Michael A.; Esquivel, Carlos; Eng, Tony Y.; Li, Ying; Papanikolaou, Nikos [University of Texas Health Science Center, San Antonio, Texas 78229 (United States)
2013-09-15
Purpose: To evaluate the neutron and photon dose equivalent rates at the treatment vault entrance (H{sub n,D} and H{sub G}), and to study the secondary radiation to the patient in GRID therapy. The radiation activation on the grid was studied.Methods: A Varian Clinac 23EX accelerator was working at 18 MV mode with a grid manufactured by .decimal, Inc. The H{sub n,D} and H{sub G} were measured using an Andersson–Braun neutron REM meter, and a Geiger Müller counter. The radiation activation on the grid was measured after the irradiation with an ion chamber γ-ray survey meter. The secondary radiation dose equivalent to patient was evaluated by etched track detectors and OSL detectors on a RANDO{sup ®} phantom.Results: Within the measurement uncertainty, there is no significant difference between the H{sub n,D} and H{sub G} with and without a grid. However, the neutron dose equivalent to the patient with the grid is, on average, 35.3% lower than that without the grid when using the same field size and the same amount of monitor unit. The photon dose equivalent to the patient with the grid is, on average, 44.9% lower. The measured average half-life of the radiation activation in the grid is 12.0 (±0.9) min. The activation can be categorized into a fast decay component and a slow decay component with half-lives of 3.4 (±1.6) min and 15.3 (±4.0) min, respectively. There was no detectable radioactive contamination found on the surface of the grid through a wipe test.Conclusions: This work indicates that there is no significant change of the H{sub n,D} and H{sub G} in GRID therapy, compared with a conventional external beam therapy. However, the neutron and scattered photon dose equivalent to the patient decrease dramatically with the grid and can be clinical irrelevant. Meanwhile, the users of a grid should be aware of the possible high dose to the radiation worker from the radiation activation on the surface of the grid. A delay in handling the grid after the beam
Forced Vibration Analysis for a FGPM Cylindrical Shell
Directory of Open Access Journals (Sweden)
Hong-Liang Dai
2013-01-01
Full Text Available This article presents an analytical study for forced vibration of a cylindrical shell which is composed of a functionally graded piezoelectric material (FGPM. The cylindrical shell is assumed to have two-constituent material distributions through the thickness of the structure, and material properties of the cylindrical shell are assumed to vary according to a power-law distribution in terms of the volume fractions for constituent materials, the exact solution for the forced vibration problem is presented. Numerical results are presented to show the effect of electric excitation, thermal load, mechanical load and volume exponent on the static and force vibration of the FGPM cylindrical shell. The goal of this investigation is to optimize the FGPM cylindrical shell in engineering, also the present solution can be used in the forced vibration analysis of cylindrical smart elements.
Energy Technology Data Exchange (ETDEWEB)
Collard, L.B.
2000-09-26
This revision was prepared to address comments from DOE-SR that arose following publication of revision 0. This Special Analysis (SA) addresses disposal of wastes with high concentrations of I-129 in the Intermediate-Level (IL) Vaults at the operating, low-level radioactive waste disposal facility (the E-Area Low-Level Waste Facility or LLWF) on the Savannah River Site (SRS). This SA provides limits for disposal in the IL Vaults of high-concentration I-129 wastes, including activated carbon beds from the Effluent Treatment Facility (ETF), based on their measured, waste-specific Kds.
Optical inspection system for cylindrical objects
Brenden, Byron B.; Peters, Timothy J.
1989-01-01
In the inspection of cylindrical objects, particularly O-rings, the object is translated through a field of view and a linear light trace is projected on its surface. An image of the light trace is projected on a mask, which has a size and shape corresponding to the size and shape which the image would have if the surface of the object were perfect. If there is a defect, light will pass the mask and be sensed by a detector positioned behind the mask. Preferably, two masks and associated detectors are used, one mask being convex to pass light when the light trace falls on a projection from the surface and the other concave, to pass light when the light trace falls on a depression in the surface. The light trace may be either dynamic, formed by a scanned laser beam, or static, formed by such a beam focussed by a cylindrical lens. Means are provided to automatically keep the illuminating receiving systems properly aligned.
Vibration analysis of bimodulus laminated cylindrical panels
Khan, K.; Patel, B. P.; Nath, Y.
2009-03-01
This paper deals with the flexural vibration behavior of bimodular laminated composite cylindrical panels with various boundary conditions. The formulation is based on first order shear deformation theory and Bert's constitutive model. The governing equations are derived using finite element method and Lagrange's equation of motion. An iterative eigenvalue approach is employed to obtain the positive and negative half cycle free vibration frequencies and corresponding mode shapes. A detailed parametric study is carried out to study the influences of thickness ratio, aspect ratio, lamination scheme, edge conditions and bimodularity ratio on the free vibration characteristics of bimodulus angle- and cross-ply composite laminated cylindrical panels. It is interesting to observe that there is a significant difference between the frequencies of positive and negative half cycles depending on the panel parameters. Through the thickness distribution of modal stresses for positive half cycle is significantly different from that for negative half cycle unlike unimodular case wherein the stresses at a particular location in negative half cycle would be of same magnitude but of opposite sign of those corresponding to positive half cycle. Finally, the effect of bimodularity on the steady state response versus forcing frequency relation is studied for a typical case.
Multimode interaction in axially excited cylindrical shells
Directory of Open Access Journals (Sweden)
Silva F. M. A.
2014-01-01
Full Text Available Cylindrical shells exhibit a dense frequency spectrum, especially near the lowest frequency range. In addition, due to the circumferential symmetry, frequencies occur in pairs. So, in the vicinity of the lowest natural frequencies, several equal or nearly equal frequencies may occur, leading to a complex dynamic behavior. So, the aim of the present work is to investigate the dynamic behavior and stability of cylindrical shells under axial forcing with multiple equal or nearly equal natural frequencies. The shell is modelled using the Donnell nonlinear shallow shell theory and the discretized equations of motion are obtained by applying the Galerkin method. For this, a modal solution that takes into account the modal interaction among the relevant modes and the influence of their companion modes (modes with rotational symmetry, which satisfies the boundary and continuity conditions of the shell, is derived. Special attention is given to the 1:1:1:1 internal resonance (four interacting modes. Solving numerically the governing equations of motion and using several tools of nonlinear dynamics, a detailed parametric analysis is conducted to clarify the influence of the internal resonances on the bifurcations, stability boundaries, nonlinear vibration modes and basins of attraction of the structure.
Data fusion for cylindrical form measurements
Liu, Pei; Jusko, Otto; Tutsch, Rainer
2015-12-01
For high-precision form measurements of cylindrical workpieces form profiles such as roundness and straightness profiles are independently acquired via a bird-cage strategy. The 3D point cloud reconstructed by fusing these intersected profiles is meaningful in dimension and form assessment for cylinder, since enhanced accuracy can be achieved by fusion results. Moreover, it plays an important role as the input to other calculations. However, these data cannot be accurately aligned in form reconstruction, due to random absolute offsets in profiles and a lack of absolute positions. Therefore, we propose an approach to data fusion of these profiles to reconstruct cylindrical form. The uncertainties of the fused profile are evaluated, taking an individual contribution of a single profile and a global contribution of all profiles into account. The associated uncertainties are propagated using the Monte Carlo method. Experimental study results indicate that the data fusion procedure improves the accuracy of available datasets. After fusion, all available data points are capable of being used in the form assessment.
Code Verification of Magnetized Cylindrical Liner Implosions
Hess, Mark; Weis, Matthew; Martin, Matthew; Sefkow, Adam; Nakhleh, Charles; Lau, Y. Y.
2012-10-01
We investigate the physics of magnetized cylindrical liner implosions with existing MHD codes to verify code accuracy, as well as to understand parametric behavior on figures-of-merit, e.g. radial liner velocity, for designing experiments. In our problem, we assume that there exists a 1-D metallic cylindrical liner with an initial axial magnetic seed field imposed in the system. The liner radially implodes due to a specified drive current while the effects of liner pressure and magnetic seed field compression oppose the implosion. This problem is of importance for future magnetized liner fusion experiments, e.g. MagLIF [1].[4pt]Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. [4pt] [1] S.A. Slutz et al, Phys. Plasmas 17, 056303 (2010).
Low distortion laser welding of cylindrical components
Kittel, Sonja
2011-02-01
Automotive components are for the most part cylindrical and thus the weld seams are of radial shape. Radial weld seams are usually produced by starting at a point on the component's surface rotating the component resulting in an overlap zone at the start/end of the weld. In this research, it is shown that the component's distortion strongly depends on the overlap of weld start and end. A correlation between overlap zone and distortion is verified by an experimental study. In order to reduce distortion generated by the overlap zone a special optics is used which allows shaping the laser beam into a ring shape which is then focused on the cylindrical surface and produces a radial ring weld seam simultaneously by one laser pulse. In doing this, the overlap zone is eliminated and distortion can be reduced. Radial weld seams are applied on precision samples and distortion is measured after welding. The distortion of the precision samples is measured by a tactile measuring method and a comparison of the results of welding with the ring optics to reference welds is done.
Techniques used in high-scoring and low-scoring 'Roche' vaults performed by elite male gymnasts.
Takei, Yoshiaki; Dunn, J Hubert; Blucker, Erik
2003-07-01
The 16 highest-scored Roche vaults (G1) performed during the 2000 Olympic Games were compared with those receiving the 16 lowest-scores (G2). A 16-mm motion picture camera operating at 100 Hz recorded the vaults during the competition. The results of t tests (p vertical force and backward horizontal force exerted by the board, greater change in the vertical velocity while on the board, and greater vertical velocity at board take-off, (b) comparable linear and angular motions in pre-flight, (c) smaller backward horizontal impulse exerted by the horse, smaller loss of the horizontal velocity while on the horse, and greater horizontal and vertical velocities at horse take-off, (d) greater height and larger horizontal distance of post-flight, (e) higher body mass centre at knee release, and (f) higher mass centre, greater normalised moment of inertia, and smaller vertical velocity at mat touchdown. Therefore, gymnasts and coaches should focus on sprinting the approach; blocking and pushing-off the take-off board rapidly and vigorously; departing the board with a large vertical velocity; exerting large downward vertical force and small forward horizontal force from the hand-stand position while on the horse; departing the horse with large horizontal and vertical velocities; and completing the majority of the double salto forward near the peak of trajectory and releasing the knees above the top of the horse to prepare for a controlled landing.
Energy Technology Data Exchange (ETDEWEB)
Hutter, H.P.; Moshammer, H.; Kundi, M. [Medizinische Univ. Wien (Austria). Inst. fuer Umwelthygiene; Wallner, P. [Medizin und Umweltschutz (mus), Wien (Austria); Damberger, B. [Oesterreichisches Inst. fuer Baubiologie und -oekologie, Wien (Austria); Tappler, P. [Oesterreichisches Inst. fuer Baubiologie und -oekologie, Wien (Austria); Donau Univ. Krems (Austria). Dept. fuer Bauen und Umwelt; Schleritzko, K. [Architekt DI Wolfgang Brenner, Wien (Austria)
2007-07-01
In the course of restoration work carried out on Vienna's Imperial Burial Vault, workers upon removing bituminous material developed acute skin reactions. A detailed medical history of the workers was taken and an inspection by a multidisciplinary team was carried out. As a result, samples from the wallmaterial of the Imperial Burial Vault were taken for analysis of polycyclic aromatic hydrocarbons (PAH). The results of this analysis (PAH 1.900 mg/kg) confirmed that carbolineum/creosote had been used. For the restoration work that followed extensive safety measures for the workers were introduced to prevent direct exposure to dust. Furthermore, indoor air measurements were conducted to assess the outcome of applied measures. PAH concentrations were reduced to negligible amounts. The acute health problems of the workers were managed quickly and effectively. No further health problems of the workers were reported, which is probably due to prompt introduction of safety measures. With restoration work of this kind, the most common exposure usually is to moulds. This case demonstrates, however, that even today the possibility of exposure to toxic materials, which were historically used, has to be considered. (orig.)
Peculiarities of carrying capacity evaluations of cylindrical CFST columns with new type casing
Directory of Open Access Journals (Sweden)
Sinkovskaya Olena
2017-01-01
Full Text Available This paper deals with a cylindrical steel-concrete load-bearing unit. The feature of the unit is a steel mesh casing that is made from the expanded metal mesh. The optimal parameters of the suggested footing are determined taking into account anisotropy, i. e. different strength and rigidity in different directions that coincide and do not coincide with the direction of reinforcement. The optimal cell angle, when a casing deformation brings about maximum compression of a concrete core, is determined. Details for theoretical calculation of the bearing capacity of a cylindrical steel-concrete load-bearing unit are provided taking into consideration a complex three-dimensional structure of the suggested mesh casing. The validity of the calculations is confirmed by comparison them with the results of the Lira software package. The results of the calculations are provided in the form of the table showing the dependence of the adduced thickness of the plate on the longitudinal movement of the strip of the steel mesh casing. The dependencies to determine the adduced thickness of the mesh casing using the graphical method are provided for all the existing types of the mesh using concrete wedges or excluding them.
Development of laser ruler in rigid laryngoscope.
Lee, Young-Ok; Kim, Byoung-Chul; Lee, Jung-Hoon; Lee, Jin-Choon; Lee, Byung-Joo; Wang, Soo-Geun; Ro, Jung-Hoon; Jeon, Gye-Rok; Shin, Bum-Joo
2011-12-01
The objective of this study was to develop a new device that provides a simple, noninvasive method of measuring accurate lesion size while using an endoscope. We developed a rigid laryngoscope with a built-in laser-ruler using a one-light emitting diode and an acrylic plate. The invention incorporates a built-in laser diode that projects an auto-parallel beam into the optical path of the rigid laryngoscope to form two spots in the field of view. While the interspot distance remains consistent despite changes in focal plane, magnification, or viewing angle of the laryngoscope, projection to an uneven surface introduces certain variations in the shape, and size of the spots, and the distance between the two spots. The device enables a laryngologist to easily measure the distance between landmarks, as well as the change in real size, and the progressive change of vocal fold lesions in an outpatient setting.
Financial Constraints and Nominal Price Rigidities
DEFF Research Database (Denmark)
Menno, Dominik Francesco; Balleer, Almut; Hristov, Nikolay
This paper investigates how financial market imperfections and the frequency of price adjustment interact. Based on new firm-level evidence for Germany, we document that financially constrained firms adjust prices more often than their unconstrained counterparts, both upwards and downwards. We show...... that these empirical patterns are consistent with a partial equilibrium menu-cost model with a working capital constraint. We then use the model to show how the presence of financial frictions changes profits and the price distribution of firms compared to a model without financial frictions. Our results suggest...... that tighter financial constraints are associated with higher nominal rigidities, higher prices and lower output. Moreover, in response to aggregate shocks, aggregate price rigidity moves substantially, the response of inflation is dampened, while output reacts more in the presence of financial frictions...
Rigid cohomology over Laurent series fields
Lazda, Christopher
2016-01-01
In this monograph, the authors develop a new theory of p-adic cohomology for varieties over Laurent series fields in positive characteristic, based on Berthelot's theory of rigid cohomology. Many major fundamental properties of these cohomology groups are proven, such as finite dimensionality and cohomological descent, as well as interpretations in terms of Monsky-Washnitzer cohomology and Le Stum's overconvergent site. Applications of this new theory to arithmetic questions, such as l-independence and the weight monodromy conjecture, are also discussed. The construction of these cohomology groups, analogous to the Galois representations associated to varieties over local fields in mixed characteristic, fills a major gap in the study of arithmetic cohomology theories over function fields. By extending the scope of existing methods, the results presented here also serve as a first step towards a more general theory of p-adic cohomology over non-perfect ground fields. Rigid Cohomology over Laurent Series Fields...
Adaptive Control of Rigid Body Satellite
Institute of Scientific and Technical Information of China (English)
Thawar T. Arif
2008-01-01
The minimal controller synthesis (MCS) is an extension of the hyperstable model reference adaptive control algorithm. The aim of minimal controller synthesis is to achieve excellent closed-loop control despite the presence of plant parameter variations, external disturbances, dynamic coupling within the plant and plant nonlinearities. The minimal controller synthesis algorithm was successfully applied to the problem of decentralized adaptive schemes. The decentralized minimal controller synthesis adaptive control strategy for controlling the attitude of a rigid body satellite is adopted in this paper. A model reference adaptive control strategy which uses one single three-axis slew is proposed for the purpose of controlling the attitude of a rigid body satellite. The simulation results are excellent and show that the controlled system is robust against disturbances.
Quantum mechanics of a generalised rigid body
Gripaios, Ben
2015-01-01
We consider the quantum version of Arnold's generalisation of a rigid body in classical mechanics. Thus, we quantise the motion on an arbitrary Lie group manifold of a particle whose classical trajectories correspond to the geodesics of any one-sided-invariant metric. We show how the derivation of the spectrum of energy eigenstates can be simplified by making use of automorphisms of the Lie algebra and (for groups of Type I) by methods of harmonic analysis. As examples, we consider all connected and simply-connected Lie groups up to dimension 3. This includes the universal cover of the archetypical rigid body, along with a number of new exactly-solvable models. We also discuss a possible application to the topical problem of quantising a perfect fluid.
Lectures on formal and rigid geometry
Bosch, Siegfried
2014-01-01
A first version of this work appeared in 2005 as a Preprint of the Collaborative Research Center "Geometrical Structures in Mathematics" at the University of Münster. Its aim was to offer a concise and self-contained 'lecture-style' introduction to the theory of classical rigid geometry established by John Tate, together with the formal algebraic geometry approach launched by Michel Raynaud. These Lectures are now viewed commonly as an ideal means of learning advanced rigid geometry, regardless of the reader's level of background. Despite its parsimonious style, the presentation illustrates a number of key facts even more extensively than any other previous work. This Lecture Notes Volume is a revised and slightly expanded version of the original preprint and has been published at the suggestion of several experts in the field.
Magnetostatic interactions and forces between cylindrical permanent magnets
Energy Technology Data Exchange (ETDEWEB)
Vokoun, David [Institute of Physics ASCR, v.v.i., Prague (Czech Republic)], E-mail: vokoun@fzu.cz; Beleggia, Marco [Institute for Materials Research, University of Leeds, Leeds LS2 9JT (United Kingdom); Heller, Ludek; Sittner, Petr [Institute of Physics ASCR, v.v.i., Prague (Czech Republic)
2009-11-15
Permanent magnets of various shapes are often utilized in magnetic actuators, sensors or releasable magnetic fasteners. Knowledge of the magnetic force is required to control devices reliably. Here, we introduce an analytical expression for calculating the attraction force between two cylindrical permanent magnets on the assumption of uniform magnetization. Although the assumption is not fulfilled exactly in cylindrical magnets, we obtain a very good agreement between the calculated and measured forces between two identical cylindrical magnets and within an array of NdFeB cylindrical magnets.
Magnetostatic interactions and forces between cylindrical permanent magnets
Vokoun, David; Beleggia, Marco; Heller, Luděk; Šittner, Petr
2009-11-01
Permanent magnets of various shapes are often utilized in magnetic actuators, sensors or releasable magnetic fasteners. Knowledge of the magnetic force is required to control devices reliably. Here, we introduce an analytical expression for calculating the attraction force between two cylindrical permanent magnets on the assumption of uniform magnetization. Although the assumption is not fulfilled exactly in cylindrical magnets, we obtain a very good agreement between the calculated and measured forces between two identical cylindrical magnets and within an array of NdFeB cylindrical magnets.
Design of Overlays for Rigid Airport Pavements
1988-04-01
Renture, A., and Mindess , S. 1986. "The Effect of Concrete Strength on Crack Patterns," Cement and Concrete Research,_ Vol 16, Pergamon Press Ltd...34 Miscellaneous Paper S-74-30, US Army Engineer Waterways Experiment Station, Vicksburg, Miss. 22. Harr, M. E. 1977 . Mechanics of Particulate Media...of Civil -. Engineers, New York. 33. Hutchinson, R., and Vedros, P. 1977 . "Performance of Heavy-Load Port- land Cement Concrete (Rigid) Airfield
Criteria for Hull-Machinery Rigidity Compatibility,
1981-05-01
articulated double-reduction gear design permits a * greater variety of arrangements with essentially the same rotating parts by rolling the pinion and...Additional intercostal girders are to be fitted within the double bottom to ensure the satisfactory distribution of the weight and the rigidity of the...and 124 arranged to distribute the loads effectively into the adjacent structure. Extra intercostal girders, effect- ively attached, are to be fitted
Rigidity of contractions on Hilbert spaces
Eisner, Tanja
2009-01-01
We study the asymptotic behaviour of contractive operators and strongly continuous semigroups on separable Hilbert spaces using the notion of rigidity. In particular, we show that a "typical" contraction $T$ contains the unit circle times the identity operator in the strong limit set of its powers, while $T^{n_j}$ converges weakly to zero along a sequence $\\{n_j\\}$ with density one. The continuous analogue is presented for isometric ang unitary $C_0$-(semi)groups.
Effectiveness of transverse grooves in rigid pavement
Gurney, G. F.; Bryden, J. E.
1982-10-01
Transverse grooves were installed at 11 intersection approaches on worn rigid pavement to reduce a high rate of wet road accidents. In most cases, accident reductions were experienced only at intersections with multiple negative operational characteristics, including higher approach speeds, limited sight distances, and frequent vehicle stopping for turns or stop signs. Intersections with no more than one negative characteristic generally did not benefit from grooving.
Rigid geometry of curves and their Jacobians
Lütkebohmert, Werner
2016-01-01
This book presents some of the most important aspects of rigid geometry, namely its applications to the study of smooth algebraic curves, of their Jacobians, and of abelian varieties - all of them defined over a complete non-archimedean valued field. The text starts with a survey of the foundation of rigid geometry, and then focuses on a detailed treatment of the applications. In the case of curves with split rational reduction there is a complete analogue to the fascinating theory of Riemann surfaces. In the case of proper smooth group varieties the uniformization and the construction of abelian varieties are treated in detail. Rigid geometry was established by John Tate and was enriched by a formal algebraic approach launched by Michel Raynaud. It has proved as a means to illustrate the geometric ideas behind the abstract methods of formal algebraic geometry as used by Mumford and Faltings. This book should be of great use to students wishing to enter this field, as well as those already working in it.
Origin of Rigidity in Dry Granular Solids
Sarkar, Sumantra; Bi, Dapeng; Zhang, Jie; Behringer, R. P.; Chakraborty, Bulbul
2013-08-01
Solids are distinguished from fluids by their ability to resist shear. In traditional solids, the resistance to shear is associated with the emergence of broken translational symmetry as exhibited by a nonuniform density pattern. In this work, we focus on the emergence of shear rigidity in a class of solids where this paradigm is challenged. Dry granular materials have no energetically or entropically preferred density modulations. We show that, in contrast to traditional solids, the emergence of shear rigidity in these granular solids is a collective process, which is controlled solely by boundary forces, the constraints of force and torque balance, and the positivity of the contact forces. We develop a theoretical framework based on these constraints, which connects rigidity to broken translational symmetry in the space of forces, not positions of grains. We apply our theory to experimentally generated shear-jammed states and show that these states are indeed characterized by a persistent, non-uniform density modulation in force space, which emerges at the shear-jamming transition.
DGP cosmology from rigid geodetic brane gravity
Cordero, Rubén; Molgado, Alberto; Rojas, Efrain
2011-01-01
We explore the cosmological implications provided by an effective geometrical action describing a codimension-one rigid brane embedded in a 5D fixed Minkowski spacetime, i.e., allowing for a term added to the geodetic brane action which depends on the extrinsic curvature of the worldvolume. In the geodetic brane gravity action we accommodate the rigidity of the brane through a linear term in the extrinsic curvature swept out by the brane. We study the resulting geodetic type equation of motion. Within a Friedmann-Robertson-Walker framework, we obtain a generalized Friedmann equation describing the associated cosmological evolution which in turn allowed us to illustrate explicitly the linkage between the geodetic brane theory and the rigidity content of this sort of branelike universes. We observe that, when the radiation-like energy contribution from the extra dimension is vanishing, this effective model leads to a self-(non-self)-accelerated expansion of the universe in dependence on the nature of the rigidi...
Institute of Scientific and Technical Information of China (English)
赵元吉
2015-01-01
运用文献资料、录像资料等，梳理当今世界男子跳马运动员的动作选择趋向及变化规律，对男子跳马优秀运动员两跳动作组合特征进行研究，结果发现：(1)2013版FIG国际体操评分规则对于跳马项目的调整较大，动作价值普遍贬值1.0分，在此基础上对踺子上板类动作进行升值，意在倡导此类动作的发展；(2)国外运动员善于采用“前手翻”接“空翻两周”动作，我国运动员倾向于采用“多度转体”类动作，踺子上板类动作的使用频率较低；(3)“前手翻类”与“侧手翻类”组合仍为当今世界优秀运动员的首选，两次世锦赛运动员共使用了3种动作组合形式，空翻类动作的使用比重依然较高，3次大赛两跳难度价值组合共出现8种形式，拥有绝对难度价值组合仍是夺冠的基础；(4)不断提高落地稳定性的同时，结合运动员特点开发新难度动作，尤其是6.0以上难度动作，采用最佳“两跳组合”方式是提高我国运动员跳马竞争力的关键。%By means of literature and video analysis, the author sorted out the trend of selection and the pattern of change of movements performed by world excellent horse vaulting male athletes, studied the characteristics of the combinations of two horse vaulting movements performed by excellent horse vaulting male athletes, and revealed the following findings: 1) in the 2013 edition of FIG International Gymnastics Scoring Rules, big adjustments were made to the vaulting horse event, movement values were depreciated by 1.0 point universally, on such a basis, movements in the Arabic spring board cate-gory were appreciated in order to promote the development of such movements; 2) foreign athletes are good at using the movement of “forward handspring” followed by “double somersault”, while Chinese athletes tend to use movements in the “multi-degree turn” category, rarely use movements in the
21 CFR 886.5916 - Rigid gas permeable contact lens.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rigid gas permeable contact lens. 886.5916 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5916 Rigid gas permeable contact lens. (a) Identification. A rigid gas permeable contact lens is a device intended to be worn...
A Cognitive Developmental Model of Rigidity in Senescence.
Lapsley, Daniel K.; Enright, Robert D.
1983-01-01
The rigidity construct is reinterpreted in terms of the cognitive developmental approach. A review reveals both cognitive and developmental themes, with an emphasis on the structural and operational properties of rigidity. Notes weaknesses of previous approaches to rigidity and discusses implications and predictions from the proposed model.…
Directory of Open Access Journals (Sweden)
U. Prisco
2010-01-01
Full Text Available Dimensional inspection of a manufactured surface by means of a coordinate measuring machine (CMM produces a set of Cartesian coordinates. The coordinates are processed to yield the geometric tolerance of the surface. This paper presents a new approach to the evaluation of flatness, cylindricity and sphericity tolerance based on surface invariance with regard to the rigid motions. The proposed algorithm transforms, through homogeneous transformation matrices, the coordinates measured to best fit the reference element of the surface class from which the actual measurements were sampled. The transformation matrix is simplified taking into account the invariance of the sum of the squared normal distances of the measured points from the nominal surface as regards some rigid motions. This invariance is a consequence of the invariance as regards some displacements of the nominal surface from which the data points were sampled. In this way, the number of parameters to be optimised is reduced in comparison with the six parameters characterizing the general homogeneous transform matrix. The methodology was computer implemented and numerical simulations were performed for planes, cylinders, and spheres in order to validate the effectiveness of the approach. The results indicate that the proposed algorithm provides accurate and quick assessments.
AMABILI, M.; PELLICANO, F.; PAÏDOUSSIS, M. P.
1999-08-01
The study presented is an investigation of the non-linear dynamics and stability of simply supported, circular cylindrical shells containing inviscid incompressible fluid flow. Non-linearities due to large-amplitude shell motion are considered by using the non-linear Donnell's shallow shell theory, with account taken of the effect of viscous structural damping. Linear potential flow theory is applied to describe the fluid-structure interaction. The system is discretiszd by Galerkin's method, and is investigated by using a model involving seven degrees of freedom, allowing for travelling wave response of the shell and shell axisymmetric contraction. Two different boundary conditions are applied to the fluid flow beyond the shell, corresponding to: (i) infinite baffles (rigid extensions of the shell), and (ii) connection with a flexible wall of infinite extent in the longitudinal direction, permitting solution by separation of variables; they give two different kinds of dynamical behaviour of the system, as a consequence of the fact that axisymmetric contraction, responsible for the softening non-linear dynamical behaviour of shells, is not allowed if the fluid flow beyond the shell is constrained by rigid baffles. Results show that the system loses stability by divergence.
Unbalanced Cylindrical Magnetron for Accelerating Cavities Coating
Rosaz, Guillaume; Calatroni, Sergio; Sublet, Alban; Tobarelli, Mauro
2016-01-01
We report in this paper the design and qualification of a cylindrical unbalanced magnetron source. The dedicated magnetic assemblies were simulated using a finite element model. A hall-effect magnetic probe was then used to characterize those assemblies and compared to the theoretical magnet profiles. These show a good agreement between the expected and actual values. the qualification of the different magnetic assemblies was then performed by measuring the ion flux density reaching the surface of the sample to be coated using a commercial retarding field energy analyzer. The strongest unbalanced configuration shows an increase from 0.016A.cm^-2 to 0.074A.cm^-2 of the ion flux density reaching the sample surface compared to the standard balanced configuration for a pressure 5.10^-3 mbar and a plasma source power of 300W.
Free Vibration of Partially Supported Cylindrical Shells
Directory of Open Access Journals (Sweden)
S. Mirza
1995-01-01
Full Text Available The effects of detached base length on the natural frequencies and modal shapes of cylindrical shell structures were investigated in this work. Some of the important applications for this type of problem can be found in the cracked fan and rotor blades that can be idealized as partially supported shells with varying unsupported lengths. A finite element model based on small deflection linear theory was developed to obtain numerical solutions for this class of problems. The numerical results were generated for shallow shells and some of the degenerate cases are compared with other results available in the literature. The computations presented here involve a wide range of variables: material properties, aspect ratios, support conditions, and radius to base ratio.
Cylindrical wormholes with positive cosmological constant
Richarte, Mart'\\in G
2013-01-01
We construct cylindrical, traversable wormholes with finite radii by taking into account the cut-and-paste procedure for the case of cosmic string manifolds with a positive cosmological constant. Under reasonable assumptions about the equation of state of the matter located at the shell, we find that the wormhole throat undergoes a monotonous evolution provided it moves at a constant velocity. In order to explore the dynamical nonlinear behaviour of the wormhole throat, we consider that the matter at the shell is supported by anisotropic Chaplygin gas, anti-Chaplygin gas, or a mixed of Chaplygin and anti-Chaplygin gases implying that wormholes could suffer an accelerated expansion or contraction but the oscillatory behavior seems to be forbidden.
Cylindrical wormholes with positive cosmological constant
Richarte, Martín G.
2013-07-01
We construct cylindrical, traversable wormholes with finite radii by taking into account the cut-and-paste procedure for the case of cosmic string manifolds with a positive cosmological constant. Under reasonable assumptions about the equation of state of the matter located at the shell, we find that the wormhole throat undergoes a monotonous evolution provided it moves at a constant velocity. In order to explore the dynamical nonlinear behavior of the wormhole throat, we consider that the matter of the shell is supported by anisotropic Chaplygin gas, anti-Chaplygin gas, or a mixture of Chaplygin and anti-Chaplygin gases, implying that wormholes could suffer an accelerated expansion or contraction, but that oscillatory behavior seems to be forbidden.
Mathematical model of cylindrical form tolerance
Institute of Scientific and Technical Information of China (English)
蔡敏; 杨将新; 吴昭同
2004-01-01
Tolerance is essential for integration of CAD and CAM. Unfortunately, the meaning of tolerances in the national standard is expressed in graphical and language forms and is not adaptable for expression, processing and data transferring with computers. How to interpret its semantics is becoming a focus of relevant studies. This work based on the mathematical definition of form tolerance in ANSI Y 14.5.1 M-1994, established the mathematical model of form tolerance for cylindrical feature. First, each tolerance in the national standard was established by vector equation. Then on the foundation of toler-ance's mathematical definition theory, each tolerance zone's mathematical model was established by inequality based on degrees of feature. At last the variance area of each tolerance zone is derived. This model can interpret the semantics of form tolerance exactly and completely.
Mathematical model of cylindrical form tolerance
Institute of Scientific and Technical Information of China (English)
蔡敏; 杨将新; 吴昭同
2004-01-01
Tolerance is essential for integration of CAD and CAM.Unfortunately,the meaning of tolerances in the national standard is expressed in graphical and language forms and is not adaptable for expression,processing and data transferring with computers.How to interpret its semantics is becoming a focus of relevant studies.This work based on the mathematical definition of form tolerance in ANSI Y 14.5.1 M-1994,established the mathematical model of form tolerance for cylindrical feature.First,each tolerance in the national standard was established by vector equation.Then on the foundation of tolerance's mathematical definition theory,each tolerance zone's mathematical model was established by inequality based on degrees of feature.At last the variance area of each tolerance zone is derived.This model can interpret the semantics of form tolerance exactly and completely.
Study of Cylindrical Honeycomb Solar Collector
Directory of Open Access Journals (Sweden)
Atish Mozumder
2014-01-01
Full Text Available We present the results of our investigation on cylindrical honeycomb solar collector. The honeycomb has been fabricated with transparent cellulose triacetate polymer sheets. Insulation characteristics of the honeycomb were studied by varying the separation between the honeycomb and the absorber plate. The optimal value of the separation was found to be 3.3 mm for which the heat transfer coefficient is 3.06 W m−2 K−1. This supports result of previous similar experiments. Further we test the honeycomb through a field experiment conducted in Delhi (28.6°N, 77°E and found that when the incident angle of the solar radiation is within 20° then the performance of the system with the honeycomb is better than the one without the honeycomb.
SPSM and its application in cylindrical shells
Institute of Scientific and Technical Information of China (English)
NIE Wu; ZHOU Su-lian; PENG Hui
2008-01-01
In naval architectures, the structure of prismatic shell is used widely. But there is no suitable method to analyze this kind of structure. Stiffened prismatic shell method (SPSM) presented in this paper, is one of the harmonic semi-analytic methods. Theoretically, strong stiffened structure can be analyzed economically and accurately. SPSM is based on the analytical solution of the governing differential equations for orthotropic cylindrical shells. In these differential equations, the torsional stiffness, bending stiffness and the exact position of each stiffener are taken into account with the Heaviside singular function. An algorithm is introduced, in which the actions of stiffeners on shells are replaced by external loads at each stiffener position. Stiffened shells can be computed as non-stiffened shells. Eventually, the displacement solution of the equations is acquired by the introduction of Green function. The stresses in a corrugated transverse bulkhead without pier base of an oil tanker are computed by using SPSM.
Space charge emission in cylindrical diode
Energy Technology Data Exchange (ETDEWEB)
Torres-Córdoba, Rafael; Martínez-García, Edgar [Universidad Autónoma de Cd. Juárez-IIT, Cd. Juárez, Chihuahua, México (Mexico)
2014-02-15
In this paper, a mathematical model to describe cylindrical electron current emissions through a physics approximation method is presented. The proposed mathematical approximation consists of analyzing and solving the nonlinear Poisson's equation, with some determined mathematical restrictions. Our findings tackle the problem when charge-space creates potential barrier that disable the steady-state of the beam propagation. In this problem, the potential barrier effects of electron's speed with zero velocity emitted through the virtual cathode happens. The interaction between particles and the virtual cathode have been to find the inter-atomic potentials as boundary conditions from a quantum mechanics perspective. Furthermore, a non-stationary spatial solution of the electrical potential between anode and cathode is presented. The proposed solution is a 2D differential equation that was linearized from the generalized Poisson equation. A single condition was used solely, throughout the radial boundary conditions of the current density formation.
Energy Technology Data Exchange (ETDEWEB)
Torres-Diaz, I.; Cortes, A.; Rinaldi, C., E-mail: carlos.rinaldi@bme.ufl.edu [Department of Chemical Engineering, University of Puerto Rico, Mayagüez, Puerto Rico 00681-9000 (United States); Cedeño-Mattei, Y. [Department of Chemistry, University of Puerto Rico, Mayagüez, Puerto Rico 00681-9019 (United States); Perales-Perez, O. [Department of Engineering Science and Materials, University of Puerto Rico, Mayagüez, Puerto Rico 00681-9044 (United States)
2014-01-15
Ferrofluid flow in cylindrical and annular geometries under the influence of a uniform rotating magnetic field was studied experimentally using aqueous ferrofluids consisting of low concentrations (<0.01 v/v) of cobalt ferrite nanoparticles with Brownian relaxation to test the ferrohydrodynamic equations, elucidate the existence of couple stresses, and determine the value of the spin viscosity in these fluids. An ultrasound technique was used to measure bulk velocity profiles in the spin-up (cylindrical) and annular geometries, varying the intensity and frequency of the rotating magnetic field generated by a two pole stator winding. Additionally, torque measurements in the cylindrical geometry were made. Results show rigid-body like velocity profiles in the bulk, and no dependence on the axial direction. Experimental velocity profiles were in quantitative agreement with the predictions of the spin diffusion theory, with a value of the spin viscosity of ∼10{sup −8} kg m/s, two orders of magnitude larger than the value estimated earlier for iron oxide based ferrofluids, and 12 orders of magnitude larger than estimated using dimensional arguments valid in the infinite dilution limit. These results provide further evidence of the existence of couple stresses in ferrofluids and their role in driving the spin-up flow phenomenon.
Melhus, C S; Rivard, M J; Kurkomelis, J; Liddle, C B; Massé, F X
2005-01-01
In support of the effort to begin high-dose rate 252Cf brachytherapy treatments at Tufts-New England Medical Center, the shielding capabilities of a clinical accelerator vault against the neutron and photon emissions from a 1.124 mg 252Cf source were examined. Outside the clinical accelerator vault, the fast neutron dose equivalent rate was below the lower limit of detection of a CR-39 etched track detector and below 0.14 +/- 0.02 muSv h(-1) with a proportional counter, which is consistent, within the uncertainties, with natural background. The photon dose equivalent rate was also measured to be below background levels (0.1 muSv h(-1)) using an ionisation chamber and an optically stimulated luminescence dosemeter. A Monte Carlo simulation of neutron transport through the accelerator vault was performed to validate measured values and determine the thermal-energy to low-energy neutron component. Monte Carlo results showed that the dose equivalent rate from fast neutrons was reduced by a factor of 100,000 after attenuation through the vault wall, and the thermal-energy neutron dose equivalent rate would be an additional factor of 1000 below that of the fast neutrons. Based on these findings, the shielding installed in this facility is sufficient for the use of at least 5.0 mg of 252Cf.
Vliet van, E.A.; Aronica, E.; Redeker, S.; Gorter, J.A.
2004-01-01
Summary: Purpose: Because drug transporters might play a role in the development of multidrug resistance (MDR), we investigated the expression of a vesicular drug transporter, the major vault protein (MVP), in a rat model for temporal lobe epilepsy. Methods: By using real-time polymerase chain react
Ingestion of six cylindrical and four button batteries
DEFF Research Database (Denmark)
Nielsen, Simon U; Rasmussen, Morten; Hoegberg, Lotte C G
2010-01-01
We report a suicidal ingestion of six cylindrical and four button batteries, in combination with overdosed prescription medicine and smoking of cannabis.......We report a suicidal ingestion of six cylindrical and four button batteries, in combination with overdosed prescription medicine and smoking of cannabis....
Settling of a cylindrical particle in a stagnant fluid
DEFF Research Database (Denmark)
Sørensen, Henrik; Rosendahl, Lasse; Yin, Chungen;
2007-01-01
The objective of this work is to collect data and develop models for cylindrical particles which could be used in numerical multiphase flow modeling. Trajectories of cylindrical particles settling in stagnant water are filmed from two directions in order to derive detailed information on their mo...
Understanding geological processes: Visualization of rigid and non-rigid transformations
Shipley, T. F.; Atit, K.; Manduca, C. A.; Ormand, C. J.; Resnick, I.; Tikoff, B.
2012-12-01
Visualizations are used in the geological sciences to support reasoning about structures and events. Research in cognitive sciences offers insights into the range of skills of different users, and ultimately how visualizations might support different users. To understand the range of skills needed to reason about earth processes we have developed a program of research that is grounded in the geosciences' careful description of the spatial and spatiotemporal patterns associated with earth processes. In particular, we are pursuing a research program that identifies specific spatial skills and investigates whether and how they are related to each other. For this study, we focus on a specific question: Is there an important distinction in the geosciences between rigid and non-rigid deformation? To study a general spatial thinking skill we employed displays with non-geological objects that had been altered by rigid change (rotation), and two types of non-rigid change ("brittle" (or discontinuous) and "ductile" (or continuous) deformation). Disciplinary scientists (geosciences and chemistry faculty), and novices (non-science faculty and undergraduate psychology students) answered questions that required them to visualize the appearance of the object before the change. In one study, geologists and chemists were found to be superior to non-science faculty in reasoning about rigid rotations (e.g., what an object would look like from a different perspective). Geologists were superior to chemists in reasoning about brittle deformations (e.g., what an object looked like before it was broken - here the object was a word cut into many fragments displaced in different directions). This finding is consistent with two hypotheses: 1) Experts are good at visualizing the types of changes required for their domain; and 2) Visualization of rigid and non-rigid changes are not the same skill. An additional important finding is that there was a broad range of skill in both rigid and non-rigid
Antiplane SH-deformations near a surface rigid foundation above a subsurface rigid circular tunnel
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
The problem on the dynamic response of a rigid embedded foundation in the presence of an underground rigidtunnel and subjected to excitation of incident anti-plane SH waves is analyzed. By using the exact analytical solution for thetwo-dimensional SH-wave propagation in and around both the surface rigid foundation and subsurface rigid tunnel, thoseaspects of the resulting ground motions that are of special interest and importance for seismic resistant design in earthquakeanalyses have been examined. The computed amplitudes of the resulting periodic ground motions display a very complicatedwave-interference between the surface foundation and underground tunnel that lead to observed standing wave patterns,together with abrupt changes in the wave amplitudes and large amplification of the incident motions.
Rigid-only versus combined rigid and flexible percutaneous nephrolithotomy (PNL)
DEFF Research Database (Denmark)
Cracco, Cecilia M; knoll, thomas; Liatsikos, Evangelos N
2017-01-01
. Appraisal of reliable outcomes of such PNL techniques would better guide intraoperative choices and optimize surgical results. Therefore our objective was to systematically review relevant literature comparing the outcomes of rigid-only PNL and combined flexible PNLs (adding flexible nephroscopy and......INTRODUCTION: Percutaneous nephrolithotomy (PNL) is usually performed worldwide with a rigid-only antegrade approach. Daily practice suggests that adding flexible nephroscopy and/or ureteroscopy to conventional rigid PNL might improve its efficacy and safety, but available evidence is weak....../or flexible ureteroscopy) for the treatment of large and/or complex upper urinary tract calculi, with regard to efficacy and safety. EVIDENCE ACQUISITION: Ovid MedLine (R), PubMed, Scopus and Web of Science databases were searched in August 2016 to identify relevant studies. Article selection was performed...
Tunable Omnidirectional Surface Plasmon Resonance in Cylindrical Plasmonic Structure
Institute of Scientific and Technical Information of China (English)
WANG Yi; WANG Bing; ZHOU Zhi-Ping
2008-01-01
@@ The tunable omnidirectional surface plasmon resonance in the optical range is theoretically demonstrated in a cylindrical plasmonic crystal by using rigorous coupled-wave analysis.The cylindrical plasmonic crystal consists of an infinite chain of two-dimensional cylindrical metal-dielectric-dielectric-metal structures.The dispersion relation of the cylindrical plasmonic crystal is obtained by calculating the absorptance as a function of a TM-polarized incident plane wave and its in-plane wave vector.The omnidirectional surface plasmon resonance can be tuned from UV region to visible region by adjusting the thickness of the cylindrical dielectric layers.The absorption spectrum of the infinite chain of nanocylinders is also investigated for comparison.
Brownian dynamics of confined rigid bodies
Energy Technology Data Exchange (ETDEWEB)
Delong, Steven; Balboa Usabiaga, Florencio; Donev, Aleksandar, E-mail: donev@courant.nyu.edu [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)
2015-10-14
We introduce numerical methods for simulating the diffusive motion of rigid bodies of arbitrary shape immersed in a viscous fluid. We parameterize the orientation of the bodies using normalized quaternions, which are numerically robust, space efficient, and easy to accumulate. We construct a system of overdamped Langevin equations in the quaternion representation that accounts for hydrodynamic effects, preserves the unit-norm constraint on the quaternion, and is time reversible with respect to the Gibbs-Boltzmann distribution at equilibrium. We introduce two schemes for temporal integration of the overdamped Langevin equations of motion, one based on the Fixman midpoint method and the other based on a random finite difference approach, both of which ensure that the correct stochastic drift term is captured in a computationally efficient way. We study several examples of rigid colloidal particles diffusing near a no-slip boundary and demonstrate the importance of the choice of tracking point on the measured translational mean square displacement (MSD). We examine the average short-time as well as the long-time quasi-two-dimensional diffusion coefficient of a rigid particle sedimented near a bottom wall due to gravity. For several particle shapes, we find a choice of tracking point that makes the MSD essentially linear with time, allowing us to estimate the long-time diffusion coefficient efficiently using a Monte Carlo method. However, in general, such a special choice of tracking point does not exist, and numerical techniques for simulating long trajectories, such as the ones we introduce here, are necessary to study diffusion on long time scales.
Characterization of low density rigid urethane foam
Energy Technology Data Exchange (ETDEWEB)
Larsen, F.N.
1978-10-01
The chemical and mechanical properties of a low density, rigid polyurethane foam material taken from a Joint Test Assembly (JTA) after 13 years of storage were measured. Chemical analyses confirmed the composition to be Bendix Rigifoam 6003-1.5, a pentaerythritol/epsilon-caprolactone/tolyene diisocyanate polyurethane foam. Comparison of data from testing thermal and mechanical characteristics with data from a currently manufactured foam of identical composition indicates no degradation of properties had occurred. This information gives added confidence to the stockpile lifetime integrity of the Rigifoam 6003-2 foam system designated for use in other programs.
Mechanical Characterization of Rigid Polyurethane Foams.
Energy Technology Data Exchange (ETDEWEB)
Lu, Wei-Yang
2014-12-01
Foam materials are used to protect sensitive components from impact loading. In order to predict and simulate the foam performance under various loading conditions, a validated foam model is needed and the mechanical properties of foams need to be characterized. Uniaxial compression and tension tests were conducted for different densities of foams under various temperatures and loading rates. Crush stress, tensile strength, and elastic modulus were obtained. A newly developed confined compression experiment provided data for investigating the foam flow direction. A biaxial tension experiment was also developed to explore the damage surface of a rigid polyurethane foam.
Rigid Body Mechanics Mathematics, Physics and Applications
Heard, William B
2005-01-01
This textbook is a modern, concise and focused treatment of the mathematical techniques, physical theories and applications of rigid body mechanics, bridging the gap between the geometric and more classical approaches to the topic. It emphasizes the fundamentals of the subject, stresses the importance of notation, integrates the modern geometric view of mechanics and offers a wide variety of examples -- ranging from molecular dynamics to mechanics of robots and planetary rotational dynamics. The author has unified his presentation such that applied mathematicians, mechanical and astro-aerodyna
Diffraction of sound by nearly rigid barriers
Hadden, W. J., Jr.; Pierce, A. D.
1976-01-01
The diffraction of sound by barriers with surfaces of large, but finite, acoustic impedance was analyzed. Idealized source-barrier-receiver configurations in which the barriers may be considered as semi-infinite wedges are discussed. Particular attention is given to situations in which the source and receiver are at large distances from the tip of the wedge. The expression for the acoustic pressure in this limiting case is compared with the results of Pierce's analysis of diffraction by a rigid wedge. An expression for the insertion loss of a finite impedance barrier is compared with insertion loss formulas which are used extensively in selecting or designing barriers for noise control.
Mechanical Characterization of Rigid Polyurethane Foams
Energy Technology Data Exchange (ETDEWEB)
Lu, Wei-Yang [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Mechanics of Materials
2014-12-01
Foam materials are used to protect sensitive components from impact loading. In order to predict and simulate the foam performance under various loading conditions, a validated foam model is needed and the mechanical properties of foams need to be characterized. Uniaxial compression and tension tests were conducted for different densities of foams under various temperatures and loading rates. Crush stress, tensile strength, and elastic modulus were obtained. A newly developed confined compression experiment provided data for investigating the foam flow direction. A biaxial tension experiment was also developed to explore the damage surface of a rigid polyurethane foam.
Oreni, D.; Brumana, R.; Georgopoulos, A.; Cuca, B.
2013-07-01
The paper illustrates the utility to switch from a 3D content model to a Historic Building Information Modelling (HBIM) in order to support conservation and management of built heritage. This three dimensional solution is based on simplified parametric models, suitable for industrial elements and modern architecture, that can be usefully applied to heritage documentation and management of the data on conservation practices. In this sense, the potentials in starting the definition of an HBIM targeted library are investigated, towards the logic of object data definition, beginning from surface surveying and representation. In order to motivate the opportunity in using this 3D object modelling instruments, some case studies are investigated in the paper. Vault and wooden bean floor analysis show how a HBIM for architectural heritage could be implemented in order to assemble different kind of data on historical buildings, such as e.g. dimensional, geometrical, thematic, historical and architectural information.
Directory of Open Access Journals (Sweden)
S Sateesh Chavan
2012-01-01
Full Text Available Chondroblastoma of squamous part of temporal bone is a very rare bone tumor. Although most of them are benign, the prognosis is not predictable. A 14-year-old girl presented with recurrent slowly growing mass over the right side of the temporo-parietal region of skull vault. Initial curettage material showed extensive chondroid areas and diagnosed histologically as "enchondroma." Histology of completely excised recurrent mass showed identifiable chondroblastic foci. She was followed up for 3 years and was free from recurrence. Chondroblastomas at very rare sites such as squamous part of temporal bone have variable histology, confusing with other giant cell lesions, variable prognosis, and require prompt diagnosis and complete excision.
Energy Technology Data Exchange (ETDEWEB)
Eibling, R.
2011-09-28
Savannah River National Laboratory (SRNL) was asked to prepare saltstone from samples of Tank 50H obtained by SRNL on April 5, 2011 (Tank 50H sampling occurred on April 4, 2011) during 2QCY11 to determine the non-hazardous nature of the grout and for additional vault classification analyses. The samples were cured and shipped to Babcock & Wilcox Technical Services Group-Radioisotope and Analytical Chemistry Laboratory (B&W TSG-RACL) to perform the Toxic Characteristic Leaching Procedure (TCLP) and subsequent extract analysis on saltstone samples for the analytes required for the quarterly analysis saltstone sample. In addition to the eight toxic metals - arsenic, barium, cadmium, chromium, mercury, lead, selenium and silver - analytes included the underlying hazardous constituents (UHC) antimony, beryllium, nickel, and thallium which could not be eliminated from analysis by process knowledge. Additional inorganic species determined by B&W TSG-RACL include aluminum, boron, chloride, cobalt, copper, fluoride, iron, lithium, manganese, molybdenum, nitrate/nitrite as Nitrogen, strontium, sulfate, uranium, and zinc and the following radionuclides: gross alpha, gross beta/gamma, 3H, 60Co, 90Sr, 99Tc, 106Ru, 106Rh, 125Sb, 137Cs, 137mBa, 154Eu, 238Pu, 239/240Pu, 241Pu, 241Am, 242Cm, and 243/244Cm. B&W TSG-RACL provided subsamples to GEL Laboratories, LLC for analysis for the VOCs benzene, toluene, and 1-butanol. GEL also determines phenol (total) and the following radionuclides: 147Pm, 226Ra and 228Ra. Preparation of the 2QCY11 saltstone samples for the quarterly analysis and for vault classification purposes and the subsequent TCLP analyses of these samples showed that: (1) The saltstone waste form disposed of in the Saltstone Disposal Facility in 2QCY11 was not characteristically hazardous for toxicity. (2) The concentrations of the eight RCRA metals and UHCs identified as possible in the saltstone waste form were present at levels below the UTS. (3) Most of the
Zheng, Yuanshui; Newhauser, Wayne; Klein, Eric; Low, Daniel
2009-11-01
Neutron production is of principal concern when designing proton therapy vault shielding. Conventionally, neutron calculations are based on analytical methods, which do not accurately consider beam shaping components and nozzle shielding. The goal of this study was to calculate, using Monte Carlo modeling, the neutron spectral fluence and neutron dose equivalent generated by a realistic proton therapy nozzle and evaluate how these data could be used in shielding calculations. We modeled a contemporary passive scattering proton therapy nozzle in detail with the MCNPX simulation code. The neutron spectral fluence and dose equivalent at various locations in the treatment room were calculated and compared to those obtained from a thick iron target bombarded by parallel proton beams, the simplified geometry on which analytical methods are based. The neutron spectral fluence distributions were similar for both methods, with deeply penetrating high-energy neutrons (E > 10 MeV) being most prevalent along the beam central axis, and low-energy neutrons predominating the neutron spectral fluence in the lateral region. However, unlike the inverse square falloff used in conventional analytical methods, this study shows that the neutron dose equivalent per therapeutic dose in the treatment room decreased with distance approximately following a power law, with an exponent of about -1.63 in the lateral region and -1.73 in the downstream region. Based on the simulated data according to the detailed nozzle modeling, we developed an empirical equation to estimate the neutron dose equivalent at any location and distance in the treatment vault, e.g. for cases in which detailed Monte Carlo modeling is not feasible. We applied the simulated neutron spectral fluence and dose equivalent to a shielding calculation as an example.
Zheng, Yuanshui; Newhauser, Wayne; Klein, Eric; Low, Daniel
2009-11-21
Neutron production is of principal concern when designing proton therapy vault shielding. Conventionally, neutron calculations are based on analytical methods, which do not accurately consider beam shaping components and nozzle shielding. The goal of this study was to calculate, using Monte Carlo modeling, the neutron spectral fluence and neutron dose equivalent generated by a realistic proton therapy nozzle and evaluate how these data could be used in shielding calculations. We modeled a contemporary passive scattering proton therapy nozzle in detail with the MCNPX simulation code. The neutron spectral fluence and dose equivalent at various locations in the treatment room were calculated and compared to those obtained from a thick iron target bombarded by parallel proton beams, the simplified geometry on which analytical methods are based. The neutron spectral fluence distributions were similar for both methods, with deeply penetrating high-energy neutrons (E > 10 MeV) being most prevalent along the beam central axis, and low-energy neutrons predominating the neutron spectral fluence in the lateral region. However, unlike the inverse square falloff used in conventional analytical methods, this study shows that the neutron dose equivalent per therapeutic dose in the treatment room decreased with distance approximately following a power law, with an exponent of about -1.63 in the lateral region and -1.73 in the downstream region. Based on the simulated data according to the detailed nozzle modeling, we developed an empirical equation to estimate the neutron dose equivalent at any location and distance in the treatment vault, e.g. for cases in which detailed Monte Carlo modeling is not feasible. We applied the simulated neutron spectral fluence and dose equivalent to a shielding calculation as an example.
Public policies targeting labour market rigidities
Directory of Open Access Journals (Sweden)
Andreea Claudia ŞERBAN
2013-02-01
Full Text Available Labour market rigidity becomes an issue of increasing importance under conditions of shocks associated with the economic crisis due to the need to increase the adaptability and responsiveness to them. Thus, labour market policies must be directed towards mitigating rigidities caused by institutional or demographic factors or certain mismatch between demand and supply of education qualifications. This paper highlights the major role of the active labour market policies targeting the increase of labour flexibility, stressing the importance and impact on the ability to adapt quickly and effectively to macroeconomic shocks. Located on a declining trend in the years preceding the crisis, spending on labour market policies increased in 2009 in all the Member States of the European Union. Spending differences are significant between countries, Romania being at the lowest end of the European Union. This requires special attention because the increased adaptability of workers through training, as active measure, is of major importance considering the increased speed of changes in the labour market.
Understanding rigid body motion in arbitrary dimensions
Leyvraz, Francois
2014-01-01
Why would anyone wish to generalize the already unappetizing subject of rigid body motion to an arbitrary number of dimensions? At first sight, the subject seems to be both repellent and superfluous. The author will try to argue that an approach involving no specifically three-dimensional constructs is actually easier to grasp than the traditional one and might thus be generally useful to understand rigid body motion both in three dimensions and in the general case. Specific differences between the viewpoint suggested here and the usual one include the following: here angular velocities are systematically treated as antisymmetric matrices, a symmetric tensor $I$ quite different from the moment of inertia tensor plays a central role, whereas the latter is shown to be a far more complex object, namely a tensor of rank four. A straightforward way to define it is given. The Euler equation is derived and the use of Noether's theorem to obtain conserved quantities is illustrated. Finally the equation of motion for ...
Magnetic Control of Rigid Achiral Microswimmers
Cheang, U.; Meshkati, Farshad; Fu, Henry; Kim, Minjun
2013-11-01
We report control of rigid achiral microswimmers in low Reynolds number environments. A rotating magnetic field was used to actuate the microswimmers wirelessly by rotating the microswimmers, which produces propulsion. Previous magnetically actuated microswimmers in bulk fluids have been designed with either flexibility or chiral geometry; we show that simpler geometries with neither flexibility nor chirality can produce propulsion. The microswimmer consists of three magnetic beads conjugated using avidin-biotin linkages into an arc formation. We designed a magnetic field generator consisting of electromagnetic coils arranged in an approximate Helmholtz configuration. A highspeed camera provided realtime imaging of the microswimmers' motion in a PDMS chamber. The rigidity of the microswimmer was characterized by tracking the position of the individual beads and calculating their relative distances. As a function of field strength and rotation frequency, we observed changes in the rotational axis of the microswimmers and the corresponding effects on their velocities. The achiral microswimmers exhibited active propulsion and were controllable in both speed and direction, which demonstrates the possibility for future biomedical applications such as drug delivery.
Glycerol in micellar confinement with tunable rigidity
Lannert, Michael; Müller, Allyn; Gouirand, Emmanuel; Talluto, Vincenzo; Rosenstihl, Markus; Walther, Thomas; Stühn, Bernd; Blochowicz, Thomas; Vogel, Michael
2016-12-01
We investigate the glassy dynamics of glycerol in the confinement of a microemulsion system, which is stable on cooling down to the glass transition of its components. By changing the composition, we vary the viscosity of the matrix, while keeping the confining geometry intact, as is demonstrated by small angle X-ray scattering. By means of 2H NMR, differential scanning calorimetry, and triplet solvation dynamics we, thus, probe the dynamics of glycerol in confinements of varying rigidity. 2H NMR results show that, at higher temperatures, the dynamics of confined glycerol is unchanged compared to bulk behavior, while the reorientation of glycerol molecules becomes significantly faster than in the bulk in the deeply supercooled regime. However, comparison of different 2H NMR findings with data from calorimetry and solvation dynamics reveals that this acceleration is not due to the changed structural relaxation of glycerol, but rather due to the rotational motion of essentially rigid glycerol droplets or of aggregates of such droplets in a more fluid matrix. Thus, independent of the matrix mobility, the glycerol dynamics remains unchanged except for the smallest droplets, where an increase of Tg and, thus, a slowdown of the structural relaxation is observed even in a fluid matrix.
Shear-induced rigidity in athermal materials
Chakraborty, Bulbul; Sarkar, Sumantra
2014-03-01
In this talk, we present a minimal model of rigidity and plastic failure in solids whose rigidity emerges directly as a result of applied stresses. Examples include shear-jamming (SJ) in dry grains and discontinuous shear thickening (DST) of dense non-Brownian suspensions. Both SJ and DST states are examples of non-equilibrium, self-assembled structures that have evolved to support the load that created them. These are strongly-interacting systems where the interactions arise primarily from the strict constraints of force and torque balance at the local and global scales. Our model is based on a reciprocal-space picture that strictly enforces the local and global constraints, and is, therefore, best suited to capturing the strong correlations in these non-equilibrium systems. The reciprocal space is a tiling whose edges represent contact forces, and whose faces represent grains. A separation of scale between force fluctuations and displacements of grains is used to represent the positional disorder as quenched randomness on variables in the reciprocal space. Comparing theoretical results to experiments, we will argue that the packing fraction controls the strength of the quenched disorder. Sumantra Sarkar et al, Phys. Rev. Lett. 111, 068301 (2013)
Optimized imaging using non-rigid registration
Energy Technology Data Exchange (ETDEWEB)
Berkels, Benjamin, E-mail: berkels@aices.rwth-aachen.de [Interdisciplinary Mathematics Institute, 1523 Greene Street, University of South Carolina, Columbia, SC 29208 (United States); Binev, Peter, E-mail: binev@math.sc.edu [Interdisciplinary Mathematics Institute, 1523 Greene Street, University of South Carolina, Columbia, SC 29208 (United States); Department of Mathematics, 1523 Greene Street, University of South Carolina, Columbia, SC 29208 (United States); Blom, Douglas A., E-mail: doug.blom@sc.edu [NanoCenter, 1212 Greene Street, University of South Carolina, Columbia, SC 29208 (United States); Dahmen, Wolfgang, E-mail: dahmen@igpm.rwth-aachen.de [Interdisciplinary Mathematics Institute, 1523 Greene Street, University of South Carolina, Columbia, SC 29208 (United States); Institut für Geometrie und Praktische Mathematik, RWTH Aachen, Templergraben 55, 52056 Aachen (Germany); Sharpley, Robert C., E-mail: rcsharpley@gmail.com [Interdisciplinary Mathematics Institute, 1523 Greene Street, University of South Carolina, Columbia, SC 29208 (United States); Department of Mathematics, 1523 Greene Street, University of South Carolina, Columbia, SC 29208 (United States); Vogt, Thomas, E-mail: tvogt@mailbox.sc.edu [Interdisciplinary Mathematics Institute, 1523 Greene Street, University of South Carolina, Columbia, SC 29208 (United States); NanoCenter, 1212 Greene Street, University of South Carolina, Columbia, SC 29208 (United States); Department of Chemistry and Biochemistry, 631 Sumter Street, University of South Carolina, Columbia, SC 29208 (United States)
2014-03-01
The extraordinary improvements of modern imaging devices offer access to data with unprecedented information content. However, widely used image processing methodologies fall far short of exploiting the full breadth of information offered by numerous types of scanning probe, optical, and electron microscopies. In many applications, it is necessary to keep measurement intensities below a desired threshold. We propose a methodology for extracting an increased level of information by processing a series of data sets suffering, in particular, from high degree of spatial uncertainty caused by complex multiscale motion during the acquisition process. An important role is played by a non-rigid pixel-wise registration method that can cope with low signal-to-noise ratios. This is accompanied by formulating objective quality measures which replace human intervention and visual inspection in the processing chain. Scanning transmission electron microscopy of siliceous zeolite material exhibits the above-mentioned obstructions and therefore serves as orientation and a test of our procedures. - Highlights: • Developed a new process for extracting more information from a series of STEM images. • An objective non-rigid registration process copes with distortions. • Images of zeolite Y show retrieval of all information available from the data set. • Quantitative measures of registration quality were implemented. • Applicable to any serially acquired data, e.g. STM, AFM, STXM, etc.
Converging cylindrical shocks in ideal magnetohydrodynamics
Pullin, D. I.
2014-09-01
We consider a cylindrically symmetrical shock converging onto an axis within the framework of ideal, compressible-gas non-dissipative magnetohydrodynamics (MHD). In cylindrical polar co-ordinates we restrict attention to either constant axial magnetic field or to the azimuthal but singular magnetic field produced by a line current on the axis. Under the constraint of zero normal magnetic field and zero tangential fluid speed at the shock, a set of restricted shock-jump conditions are obtained as functions of the shock Mach number, defined as the ratio of the local shock speed to the unique magnetohydrodynamic wave speed ahead of the shock, and also of a parameter measuring the local strength of the magnetic field. For the line current case, two approaches are explored and the results compared in detail. The first is geometrical shock-dynamics where the restricted shock-jump conditions are applied directly to the equation on the characteristic entering the shock from behind. This gives an ordinary-differential equation for the shock Mach number as a function of radius which is integrated numerically to provide profiles of the shock implosion. Also, analytic, asymptotic results are obtained for the shock trajectory at small radius. The second approach is direct numerical solution of the radially symmetric MHD equations using a shock-capturing method. For the axial magnetic field case the shock implosion is of the Guderley power-law type with exponent that is not affected by the presence of a finite magnetic field. For the axial current case, however, the presence of a tangential magnetic field ahead of the shock with strength inversely proportional to radius introduces a length scale R = √μ0/p0 I/(2π) where I is the current, μ0 is the permeability, and p0 is the pressure ahead of the shock. For shocks initiated at r ≫ R, shock convergence is first accompanied by shock strengthening as for the strictly gas-dynamic implosion. The diverging magnetic field then
Converging cylindrical shocks in ideal magnetohydrodynamics
Pullin, D. I.; Mostert, W.; Wheatley, V.; Samtaney, R.
2014-09-01
We consider a cylindrically symmetrical shock converging onto an axis within the framework of ideal, compressible-gas non-dissipative magnetohydrodynamics (MHD). In cylindrical polar co-ordinates we restrict attention to either constant axial magnetic field or to the azimuthal but singular magnetic field produced by a line current on the axis. Under the constraint of zero normal magnetic field and zero tangential fluid speed at the shock, a set of restricted shock-jump conditions are obtained as functions of the shock Mach number, defined as the ratio of the local shock speed to the unique magnetohydrodynamic wave speed ahead of the shock, and also of a parameter measuring the local strength of the magnetic field. For the line current case, two approaches are explored and the results compared in detail. The first is geometrical shock-dynamics where the restricted shock-jump conditions are applied directly to the equation on the characteristic entering the shock from behind. This gives an ordinary-differential equation for the shock Mach number as a function of radius which is integrated numerically to provide profiles of the shock implosion. Also, analytic, asymptotic results are obtained for the shock trajectory at small radius. The second approach is direct numerical solution of the radially symmetric MHD equations using a shock-capturing method. For the axial magnetic field case the shock implosion is of the Guderley power-law type with exponent that is not affected by the presence of a finite magnetic field. For the axial current case, however, the presence of a tangential magnetic field ahead of the shock with strength inversely proportional to radius introduces a length scale R=sqrt{μ _0/p_0} I/(2 π ) where I is the current, μ0 is the permeability, and p0 is the pressure ahead of the shock. For shocks initiated at r ≫ R, shock convergence is first accompanied by shock strengthening as for the strictly gas-dynamic implosion. The diverging magnetic field
Parkinson's disease rigidity: relation to brain connectivity and motor performance
Directory of Open Access Journals (Sweden)
Nazanin eBaradaran
2013-06-01
Full Text Available Objective: 1 To determine the brain connectivity pattern associated with clinical rigidity scores in Parkinson's disease (PD and 2 to determine the relation between clinically-assessed rigidity and quantitative metrics of motor performance.Background: Rigidity, the resistance to passive movement, is exacerbated in PD by asking the subject to move the contralateral limb, implying that rigidity involves a distributed brain network. Rigidity mainly affects subjects when they attempt to move; yet the relation between clinical rigidity scores and quantitative aspects of motor performance are unknown.Methods: Ten clinically diagnosed PD patients (off medication and ten controls were recruited to perform an fMRI squeeze-bulb tracking task that included both visually guided and internally guided features. The direct functional connectivity between anatomically defined regions of interest was assessed with Dynamic Bayesian Networks (DBNs. Tracking performance was assessed by fitting Linear Dynamical System (LDS models to the motor performance, and was compared to the clinical rigidity scores. A cross-validated Least Absolute Shrinkage and Selection Operator (LASSO regression method was used to determine the brain connectivity network that best predicted clinical rigidity scores.Results: The damping ratio of the LDS models significantly correlated with clinical rigidity scores (p < 10-4. An fMRI connectivity network in subcortical and primary and premotor cortical regions accurately predicted clinical rigidity scores (p < 10-5. Conclusions: A widely distributed cortical/subcortical network is associated with rigidity observed in PD patients, which reinforces the importance of altered functional connectivity in the pathophysiology of PD. PD subjects with higher rigidity scores tend to have less overshoot in their tracking performance, and damping ratio may represent a robust, quantitative marker of the motoric effects of increasing rigidity.
Surface tension and long range corrections of cylindrical interfaces
Energy Technology Data Exchange (ETDEWEB)
Bourasseau, E. [CEA/DAM DIF, F-91297 Arpajon Cedex (France); Malfreyt, P. [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); Ghoufi, A., E-mail: aziz.ghoufi@univ-rennes1.fr [Institut de Physique de Rennes, UMR 6251 CNRS, Université de Rennes 1, 263 avenue Général Leclerc, 35042 Rennes (France)
2015-12-21
The calculation of the surface tension of curved interfaces has been deeply investigated from molecular simulation during this last past decade. Recently, the thermodynamic Test-Area (TA) approach has been extended to the calculation of surface tension of curved interfaces. In the case of the cylindrical vapour-liquid interfaces of water and Lennard-Jones fluids, it was shown that the surface tension was independent of the curvature of the interface. In addition, the surface tension of the cylindrical interface is higher than that of the planar interface. Molecular simulations of cylindrical interfaces have been so far performed (i) by using a shifted potential, (ii) by means of large cutoff without periodic boundary conditions, or (iii) by ignoring the long range corrections to the surface tension due to the difficulty to estimate them. Indeed, unlike the planar interfaces there are no available operational expressions to consider the tail corrections to the surface tension of cylindrical interfaces. We propose here to develop the long range corrections of the surface tension for cylindrical interfaces by using the non-exponential TA (TA2) method. We also extend the formulation of the Mecke-Winkelmann corrections initially developed for planar surfaces to cylindrical interfaces. We complete this study by the calculation of the surface tension of cylindrical surfaces of liquid tin and copper using the embedded atom model potentials.
Functional evolution of quantum cylindrical waves
Cho, D H J; Cho, Demian H.J.; Varadarajan, Madhavan
2006-01-01
Kucha{\\v{r}} showed that the quantum dynamics of (1 polarization) cylindrical wave solutions to vacuum general relativity is determined by that of a free axially-symmetric scalar field along arbitrary axially-symmetric foliations of a fixed flat 2+1 dimensional spacetime. We investigate if such a dynamics can be defined {\\em unitarily} within the standard Fock space quantization of the scalar field. Evolution between two arbitrary slices of an arbitrary foliation of the flat spacetime can be built out of a restricted class of evolutions (and their inverses). The restricted evolution is from an initial flat slice to an arbitrary (in general, curved) slice of the flat spacetime and can be decomposed into (i) `time' evolution in which the spatial Minkowskian coordinates serve as spatial coordinates on the initial and the final slice, followed by (ii) the action of a spatial diffeomorphism of the final slice on the data obtained from (i). We show that although the functional evolution of (i) is unitarily implemen...
Technology Selections for Cylindrical Compact Fabrication
Energy Technology Data Exchange (ETDEWEB)
Jeffrey A. Phillips
2010-10-01
A variety of process approaches are available and have been used historically for manufacture of cylindrical fuel compacts. The jet milling, fluid bed overcoating, and hot press compacting approach being adopted in the U.S. AGR Fuel Development Program for scale-up of the compacting process involves significant paradigm shifts from historical approaches. New methods are being pursued because of distinct advantages in simplicity, yield, and elimination of process mixed waste. Recent advances in jet milling technology allow simplified dry matrix powder preparation. The matrix preparation method is well matched with patented fluid bed powder overcoating technology recently developed for the pharmaceutical industry and directly usable for high density fuel particle matrix overcoating. High density overcoating places fuel particles as close as possible to their final position in the compact and is matched with hot press compacting which fully fluidizes matrix resin to achieve die fill at low compacting pressures and without matrix end caps. Overall the revised methodology provides a simpler process that should provide very high yields, improve homogeneity, further reduce defect fractions, eliminate intermediate grading and QC steps, and allow further increases in fuel packing fractions.
Acoustic transfer admittance of cylindrical cavities
Guianvarc'h, C.; Durocher, J.-N.; Bruneau, M.; Bruneau, A.-M.
2006-05-01
The reciprocity calibration method uses two microphones acoustically connected by a coupler, a cylindrical cavity closed at each end by the diaphragms of the transmitting and receiving microphones. The acoustic transfer admittance of the coupler, including the thermal conductivity effect of the fluid, must be modelled precisely to obtain the accurate sensitivity of the microphones from the electrical transfer impedance measurement. It appears that the analytical model quoted in the current standard [International Electrotechnical Commission IEC 61064-2, Measurement Microphones, Part 2: Primary Method for Pressure Calibration of Laboratory Standard Microphones by the Reciprocity Technique, 1992] is not the appropriate one and that it should be revised, as also suggested by a recent EUROMET project report [K. Rasmussen, Datafiles simulating a pressure reciprocity calibration of microphones, EUROMET Project 294 Report PL-13, 2001]. Thus, it is the aim of the paper to investigate analytically the acoustic field inside the coupler, revisiting the assumptions of the earlier work, leading to a coherent description and therefore providing clarity which should facilitate discussion of a possible revised standard.
Cylindrical shell buckling through strain hardening
Energy Technology Data Exchange (ETDEWEB)
Bandyopadhyay, K.; Xu, J.; Shteyngart, S. [Brookhaven National Lab., Upton, NY (United States); Gupta, D. [USDOE, Germantown, MD (United States)
1995-04-01
Recently, the authors published results of plastic buckling analysis of cylindrical shells. Ideal elastic-plastic material behavior was used for the analysis. Subsequently, the buckling analysis program was continued with the realistic stress-strain relationship of a stainless steel alloy which does not exhibit a clear yield point. The plastic buckling analysis was carried out through the initial stages of strain hardening for various internal pressure values. The computer program BOSOR5 was used for this purpose. Results were compared with those obtained from the idealized elastic-plastic relationship using the offset stress level at 0.2% strain as the yield stress. For moderate hoop stress values, the realistic stress-grain case shows a slight reduction of the buckling strength. But, a substantial gain in the buckling strength is observed as the hoop stress approaches the yield strength. Most importantly, the shell retains a residual strength to carry a small amount of axial compressive load even when the hoop stress has exceeded the offset yield strength.
Buckling localization in a cylindrical panel under axial compression
DEFF Research Database (Denmark)
Tvergaard, Viggo; Needleman, A.
2000-01-01
Localization of an initially periodic buckling pattern is investigated for an axially compressed elastic-plastic cylindrical panel of the type occurring between axial stiffeners on cylindrical shells. The phenomenon of buckling localization and its analogy with plastic flow localization in tensile...... test specimens is discussed in general. For the cylindrical panel, it is shown that buckling localization develops shortly after a maximum load has been attained, and this occurs for a purely elastic panel as well as for elastic-plastic panels. In a case where localization occurs after a load maximum...
Electromagnetic Cylindrical Transparent Devices with Irregular Cross Section
Directory of Open Access Journals (Sweden)
C. Yang
2010-04-01
Full Text Available Electromagnetic transparent device is very important for antenna protection. In this paper, the material parameters for the cylindrical transparent devices with arbitrary cross section are developed based on the coordinate transformation. The equivalent two-dimensional (2D transparent devices under TE plane and cylindrical wave irradiation is designed and studied by full-wave simulation, respectively. It shows that although the incident waves are distorted in the transformation region apparently, they return to the original wavefronts when passing through the device. All theoretical and numerical results validate the material parameters for the cylindrical transparent devices with arbitrary cross section we developed.
New cylindrical gravitational soliton waves and gravitational Faraday rotation
Tomizawa, Shinya
2013-01-01
In terms of gravitational solitons, we study gravitational non-linear effects of gravitational solitary waves such as Faraday rotation. Applying the Pomeransky's procedure for inverse scattering method, which has been recently used for constructing stationary black hole solutions in five dimensions to a cylindrical spacetime in four dimensions, we construct a new cylindrically symmetric soliton solution. This is the first example to be applied to the cylindrically symmetric case. In particular, we clarify the difference from the Tomimatsu's single soliton solution, which was constructed by the Belinsky-Zakharov's procedure.
γ-ray self-absorption of cylindrical fissile material
Institute of Scientific and Technical Information of China (English)
HUANG Yong-Yi; CHENG Yi-Ying; TIAN Dong-Feng; LU Fu-Quan; YANG Fu-Jia
2005-01-01
The self-absorption of γ-ray emitted from cylindrical fissile materials, such as 235U and 239Pu, does not possess spherical symmetry. The analytical formulae of self-absorption for γ-ray throughout the cylinder have been obtained. The intensity of γ-ray is a function of γ-ray outgoing directions and cylindrical configurations, accordingly one can acquire the information about geometrical configuration of cylindrical fissile materials through multi-location measurements. Further more, the method is given in this article. The result can be applied to the fissile material safeguard, such as nuclear monitoring and verifying.
Plasmonic Bloch oscillations in cylindrical metal-dielectric waveguide arrays.
Shiu, Ruei-Cheng; Lan, Yung-Chiang; Chen, Chin-Min
2010-12-01
This study investigates plasmonic Bloch oscillations (PBOs) in cylindrical metal-dielectric waveguide arrays (MDWAs) by performing numerical simulations and theoretical analyses. Optical conformal mapping is used to transform cylindrical MDWAs into equivalent chirped structures with permittivity and permeability gradients across the waveguide arrays, which is caused by the curvature of the cylindrical waveguide. The PBOs are attributed to the transformed structure. The period of oscillation increases with the wavelength of the incident Gaussian beam. However, the amplitude of oscillation is almost independent of wavelength.
Cylindrical array luminescent solar concentrators: performance boosts by geometric effects.
Videira, Jose J H; Bilotti, Emiliano; Chatten, Amanda J
2016-07-11
This paper presents an investigation of the geometric effects within a cylindrical array luminescent solar concentrator (LSC). Photon concentration of a cylindrical LSC increases linearly with cylinder length up to 2 metres. Raytrace modelling on the shading effects of circles on their neighbours demonstrates effective incident light trapping in a cylindrical LSC array at angles of incidence between 60-70 degrees. Raytrace modelling with real-world lighting conditions shows optical efficiency boosts when the suns angle of incidence is within this angle range. On certain days, 2 separate times of peak optical efficiency can be attained over the course of sunrise-solar noon.
Directory of Open Access Journals (Sweden)
Morteza Eskandari-Ghadi
2014-06-01
Full Text Available This paper is concerned with investigation of vertical impedance function of a surface rigid circular foundation resting on a semi-infinite transversely isotropic alluvium. To this end, the equations of motion in cylindrical coordinate system, which because of axissymmetry are two coupled equations, are converted into one partial differential equation using a method of potential function. The governing partial differential equation for the potential function is solved via implementing Hankel integral transforms in radial direction. The vertical and radial components of displacement vector are determined with the use of transformed displacement-potential function relationships. The mixed boundary conditions at the surface are satisfied by specifying the traction between the rigid foundation and the underneath alluvium in a special function space introduced in this paper, where the vertical displacements are forced to satisfy the rigid boundary condition. Through exercising these restraints, the normal traction and then the vertical impedance function are obtained. The results are then compared with the existing results in the literature for the simpler case of isotropic half-space, which shows an excellent agreement. Eventually, the impedance functions are presented in terms of dimensionless frequency for different materials. The method presented here may be used to obtain the impedance function in any other direction as well as in buried footing in layered media.
Lācis, Uǧis; Bagheri, Shervin
2015-01-01
Dispersion of low-density rigid particles with complex geometries is ubiquitous in both natural and industrial environments. We show that while explicit methods for coupling the incompressible Navier-Stokes equations and Newton's equations of motion are often sufficient to solve for the motion of cylindrical particles with low density ratios, for more complex particles - such as a body with a protrusion - they become unstable. We present an implicit formulation of the coupling between rigid body dynamics and fluid dynamics within the framework of the immersed boundary projection method. Similar to previous work on this method, the resulting matrix equation in the present approach is solved using a block-LU decomposition. Each step of the block-LU decomposition is modified to incorporate the rigid body dynamics. We show that our method achieves second-order accuracy in space and first-order in time (third-order for practical settings), only with a small additional computational cost to the original method. Our...
Weak rigidity in almost-thermodynamic material schemes
Energy Technology Data Exchange (ETDEWEB)
del Olmo, V.; Olivert, J.
1985-06-01
To avoid the restrictions that the Born rigidity supposes for the motions in relativity, the definition of a weakly rigid almost-thermodynamic material scheme is proposed. From it the relativistic incompressibility condition given by Ferrando and Olivert is obtained. Moreover, it is proved that, for the weakly rigid irrotational and geodesic almost-thermodynamic material schemes, the scalar curvature of the Landau manifolds is constant along the streamlines.
Regulation of Breast Cancer Stem Cells by Tissue Rigidity
2015-06-01
alignment by second harmonic generation imaging (SHG) and used it as a surrogate marker for tissue rigidity. In agreement with previous publications6–8,44,45...AD ____________ __ Award Number: W81XWH-13-1-0133 TITLE: Regulation of Breast Cancer Stem Cells by Tissue Rigidity PRINCIPAL INVESTIGATOR: Adam J...CONTRACT NUMBER Regulation of Breast Cancer Stem Cell by Tissue Rigidity W81XWH-13-1-0133 Sb. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR
Dual Quaternion Variational Integrator for Rigid Body Dynamic Simulation
XU, JIAFENG; Halse, Karl Henning
2016-01-01
We introduce a symplectic dual quaternion variational integrator(DQVI) for simulating single rigid body motion in all six degrees of freedom. Dual quaternion is used to represent rigid body kinematics and one-step Lie group variational integrator is used to conserve the geometric structure, energy and momentum of the system during the simulation. The combination of these two becomes the first Lie group variational integrator for rigid body simulation without decoupling translations and rotati...
Rigid curves on $\\bar M_{0,n}$ and arithmetic breaks
Castravet, Ana-Maria
2011-01-01
A result of Keel and McKernan states that a hypothetical counterexample to the F-conjecture must come from rigid curves on $\\bar {M}_{0,n}$ that intersect the interior. We exhibit several ways of constructing rigid curves. In all our examples, a reduction mod p argument shows that the classes of the rigid curves that we construct can be decomposed as sums of F-curves.
Discrete Time Crystals: Rigidity, Criticality, and Realizations
Yao, N. Y.; Potter, A. C.; Potirniche, I.-D.; Vishwanath, A.
2017-01-01
Despite being forbidden in equilibrium, spontaneous breaking of time translation symmetry can occur in periodically driven, Floquet systems with discrete time-translation symmetry. The period of the resulting discrete time crystal is quantized to an integer multiple of the drive period, arising from a combination of collective synchronization and many body localization. Here, we consider a simple model for a one-dimensional discrete time crystal which explicitly reveals the rigidity of the emergent oscillations as the drive is varied. We numerically map out its phase diagram and compute the properties of the dynamical phase transition where the time crystal melts into a trivial Floquet insulator. Moreover, we demonstrate that the model can be realized with current experimental technologies and propose a blueprint based upon a one dimensional chain of trapped ions. Using experimental parameters (featuring long-range interactions), we identify the phase boundaries of the ion-time-crystal and propose a measurable signature of the symmetry breaking phase transition.
Modeling Decomposition of Unconfined Rigid Polyurethane Foam
Energy Technology Data Exchange (ETDEWEB)
HOBBS,MICHAEL L.; ERICKSON,KENNETH L.; CHU,TZE YAO
1999-11-08
The decomposition of unconfined rigid polyurethane foam has been modeled by a kinetic bond-breaking scheme describing degradation of a primary polymer and formation of a thermally stable secondary polymer. The bond-breaking scheme is resolved using percolation theory to describe evolving polymer fragments. The polymer fragments vaporize according to individual vapor pressures. Kinetic parameters for the model were obtained from Thermal Gravimetric Analysis (TGA). The chemical structure of the foam was determined from the preparation techniques and ingredients used to synthesize the foam. Scale-up effects were investigated by simulating the response of an incident heat flux of 25 W/cm{sup 2} on a partially confined 8.8-cm diameter by 15-cm long right circular cylinder of foam that contained an encapsulated component. Predictions of center, midradial, and component temperatures, as well as regression of the foam surface, were in agreement with measurements using thermocouples and X-ray imaging.
Modeling Decomposition of Unconfined Rigid Polyurethane Foam
Energy Technology Data Exchange (ETDEWEB)
CHU,TZE YAO; ERICKSON,KENNETH L.; HOBBS,MICHAEL L.
1999-11-01
The decomposition of unconfined rigid polyurethane foam has been modeled by a kinetic bond-breaking scheme describing degradation of a primary polymer and formation of a thermally stable secondary polymer. The bond-breaking scheme is resolved using percolation theory to describe evolving polymer fragments. The polymer fragments vaporize according to individual vapor pressures. Kinetic parameters for the model were obtained from Thermal Gravimetric Analysis (TGA). The chemical structure of the foam was determined from the preparation techniques and ingredients used to synthesize the foam. Scale-up effects were investigated by simulating the response of an incident heat flux of 25 W/cm{sup 2} on a partially confined 8.8-cm diameter by 15-cm long right circular cylinder of foam which contained an encapsulated component. Predictions of center, midradial, and component temperatures, as well as regression of the foam surface, were in agreement with measurements using thermocouples and X-ray imaging.
Discrete Time Crystals: Rigidity, Criticality, and Realizations.
Yao, N Y; Potter, A C; Potirniche, I-D; Vishwanath, A
2017-01-20
Despite being forbidden in equilibrium, spontaneous breaking of time translation symmetry can occur in periodically driven, Floquet systems with discrete time-translation symmetry. The period of the resulting discrete time crystal is quantized to an integer multiple of the drive period, arising from a combination of collective synchronization and many body localization. Here, we consider a simple model for a one-dimensional discrete time crystal which explicitly reveals the rigidity of the emergent oscillations as the drive is varied. We numerically map out its phase diagram and compute the properties of the dynamical phase transition where the time crystal melts into a trivial Floquet insulator. Moreover, we demonstrate that the model can be realized with current experimental technologies and propose a blueprint based upon a one dimensional chain of trapped ions. Using experimental parameters (featuring long-range interactions), we identify the phase boundaries of the ion-time-crystal and propose a measurable signature of the symmetry breaking phase transition.
Rigidity of marginally outer trapped 2-spheres
Galloway, Gregory J
2015-01-01
In a matter-filled spacetime, perhaps with positive cosmological constant, a stable marginally outer trapped 2-sphere must satisfy a certain area inequality. Namely, as discussed in the paper, its area must be bounded above by $4\\pi/c$, where $c > 0$ is a lower bound on a natural energy-momentum term. We then consider the rigidity that results for stable, or weakly outermost, marginally outer trapped 2-spheres that achieve this upper bound on the area. In particular, we prove a splitting result for 3-dimensional initial data sets analogous to a result of Bray, Brendle and Neves [10] concerning area minimizing 2-spheres in Riemannian 3-manifolds with positive scalar curvature. We further show that these initial data sets locally embed as spacelike hypersurfaces into the Nariai spacetime. Connections to the Vaidya spacetime and dynamical horizons are also discussed.
Foam inflated rigidized structures for space applications
Lester, D. M.; Warner, M. J.; Blair, M.
1993-11-01
Large lightweight stowable structures that can be deployed in space without astronaut extra vehicular activity are vital to expanding space exploration and utilization. To meet this challenge Foam Inflated Rigidized (FIR) structures have been developed by Thiokol Corporation on the Air Forces's Gossamer Baggie Torus program. In this paper the development, proof of concept demonstration of an eight foot diameter octagonal torus, and design application of this technology for structural elements to stabilize the solar collector of a solar thermal rocket are discussed. A FIR structure uses foam to inflate and pre-stress a resin impregnated fabric skin. The predeployed foam used was a solvent swelled polymer that foams immediately when exposed to vacuum due to rapid solvent loss. This property allows a very simple deployment mechanism to be used in erecting these structures. Once inflated, the skin resin is cured using the available ultraviolet radiation. By using high strength and stiffness fiber materials a stiff, strong lightweight structure was produced.
Non-rigid precession of magnetic stars
Lander, S K
2016-01-01
Stars are, generically, rotating and magnetised objects with a misalignment between their magnetic and rotation axes. Since a magnetic field induces a permanent distortion to its host, it provides effective rigidity even to a fluid star, leading to bulk stellar motion which resembles free precession. This bulk motion is however accompanied by induced interior velocity and magnetic field perturbations, which are oscillatory on the precession timescale. Extending previous work, we show that these quantities are described by a set of second-order perturbation equations featuring cross-terms scaling with the product of the magnetic and centrifugal distortions to the star. For the case of a background toroidal field, we reduce these to a set of differential equations in radial functions, and find a method for their solution. The resulting magnetic-field and velocity perturbations show complex multipolar structure and are strongest towards the centre of the star.
On real structures on rigid surfaces
Energy Technology Data Exchange (ETDEWEB)
Kulikov, Vik S [Steklov Mathematical Institute, Russian Academy of Sciences (Russian Federation); Kharlamov, V M [Institut de Recherche Matematique Avanee Universite Louis Pasteur et CNRS 7 rue Rene Descartes (France)
2002-02-28
We construct examples of rigid surfaces (that is, surfaces whose deformation class consists of a unique surface) with a particular behaviour with respect to real structures. In one example the surface has no real structure. In another it has a unique real structure, which is not maximal with respect to the Smith-Thom inequality. These examples give negative answers to the following problems: the existence of real surfaces in each deformation class of complex surfaces, and the existence of maximal real surfaces in every complex deformation class that contains real surfaces. Moreover, we prove that there are no real surfaces among surfaces of general type with p{sub g}=q=0 and K{sup 2}=9. These surfaces also provide new counterexamples to the 'Dif = Def' problem.
Water dynamics in rigid ionomer networks
Osti, N. C.; Etampawala, T. N.; Shrestha, U. M.; Aryal, D.; Tyagi, M.; Diallo, S. O.; Mamontov, E.; Cornelius, C. J.; Perahia, D.
2016-12-01
The dynamics of water within ionic polymer networks formed by sulfonated poly(phenylene) (SPP), as revealed by quasi-elastic neutron scattering (QENS), is presented. These polymers are distinguished from other ionic macromolecules by their rigidity and therefore in their network structure. QENS measurements as a function of temperature as the fraction of ionic groups and humidity were varied have shown that the polymer molecules are immobile while absorbed water molecules remain dynamic. The water molecules occupy multiple sites, either bound or loosely constrained, and bounce between the two. With increasing temperature and hydration levels, the system becomes more dynamic. Water molecules remain mobile even at subzero temperatures, illustrating the applicability of the SPP membrane for selective transport over a broad temperature range.
Observational properties of rigidly rotating dust configurations
Ilyas, Batyr; Yang, Jinye
2016-01-01
We study the observational properties of a class of exact solutions of Einstein's field equations describing stationary, axially symmetric, rigidly rotating dust. We ask the question whether such solutions can describe astrophysical rotating dark matter clouds and we probe the possibility that they may constitute an alternative to supermassive black holes at the center of galaxies. We show that light emission from accretion disks in this space-time has several differences with respect to the emission of light from accretion disks around black holes. The shape of the iron K{\\alpha} line in the reflection spectrum of accretion disks can potentially distinguish this class of solution from the Kerr metric, but this may not be possible with current X-ray missions.
Static friction between rigid fractal surfaces.
Alonso-Marroquin, Fernando; Huang, Pengyu; Hanaor, Dorian A H; Flores-Johnson, E A; Proust, Gwénaëlle; Gan, Yixiang; Shen, Luming
2015-09-01
Using spheropolygon-based simulations and contact slope analysis, we investigate the effects of surface topography and atomic scale friction on the macroscopically observed friction between rigid blocks with fractal surface structures. From our mathematical derivation, the angle of macroscopic friction is the result of the sum of the angle of atomic friction and the slope angle between the contact surfaces. The latter is obtained from the determination of all possible contact slopes between the two surface profiles through an alternative signature function. Our theory is validated through numerical simulations of spheropolygons with fractal Koch surfaces and is applied to the description of frictional properties of Weierstrass-Mandelbrot surfaces. The agreement between simulations and theory suggests that for interpreting macroscopic frictional behavior, the descriptors of surface morphology should be defined from the signature function rather than from the slopes of the contacting surfaces.
Acoustic propagation in a rigid torus
El-Raheb, M.; Wagner, P.
1982-01-01
The acoustic propagation in a rigid torus is analyzed using a Green's function method. Three types of surface elements are developed; a flat quadrilateral element used in modeling polygonal cavities, a curved conical element appropriate for surfaces with one curvature, and a toroidal element developed for such doubly curved surfaces as the torus. Curved elements are necessary since the acoustic pressure is sensitive to slope discontinuities between consecutive surface elements especially near cavity resonances. The acoustic characteristics of the torus are compared to those of a bend of square cross section for a frequency range that includes the transverse acoustic resonance. Two equivalences between the different sections are tested; the first conserves curvature and cross-sectional dimension while the second matches transverse resonance and duct volume. The second equivalence accurately matches the acoustic characteristics of the torus up to the cutoff frequency corresponding to a mode with two circumferential waves.
Field cracking performance of airfield rigid pavements
Directory of Open Access Journals (Sweden)
Yusuf Mehta
2017-08-01
Full Text Available This paper discusses cracking in airport pavements as studied in Construction Cycle 6 of testing carried out at the National Airport Pavement Testing Facility by the Federal Aviation Administration. Pavements of three different flexural strengths as well as two different subgrades, a soft bituminous layer and a more rigid layer known as econocrete, were tested. In addition to this, cracking near two types of isolated transition joints, a reinforced edge joint and a thickened edge joint, was considered. The pavement sections were tested using a moving load simulating that of an aircraft. It has been determined that the degree of cracking was reduced as the flexural strength of the pavement was increased and that fewer cracks formed over the econocrete base than over the bituminous base. In addition, the thickened edge transition joint was more effective in preventing cracking at the edges compared to the reinforced edge joint.
A mean curvature estimate for cylindrically bounded submanifolds
Alias, Luis J
2010-01-01
We extend the estimate obtained in [1] for the mean curvature of a cylindrically bounded proper submanifold in a product manifold with an Euclidean space as one factor to a general product ambient space endowed with a warped product structure.
Cylindrical invisibility cloak with simplified material parameters is inherently visible.
Yan, Min; Ruan, Zhichao; Qiu, Min
2007-12-07
It was proposed that perfect invisibility cloaks can be constructed for hiding objects from electromagnetic illumination [J. B. Pendry, D. Schurig, and D. R. Smith, Science 312, 1780 (2006)10.1126/science.1125907]. The cylindrical cloaks experimentally demonstrated [D. Schurig, Science 314, 977 (2006)10.1126/science.1133628] and theoretically proposed [W. Cai, Nat. Photon. 1, 224 (2007)10.1038/nphoton.2007.28] have however simplified material parameters in order to facilitate easier realization as well as to avoid infinities in optical constants. Here we show that the cylindrical cloaks with simplified material parameters inherently allow the zeroth-order cylindrical wave to pass through the cloak as if the cloak is made of a homogeneous isotropic medium, and thus visible. To all high-order cylindrical waves, our numerical simulation suggests that the simplified cloak inherits some properties of the ideal cloak, but finite scatterings exist.
Response of an electrostatic probe for a right cylindrical spacer
DEFF Research Database (Denmark)
Rerup, T; Crichton, George C; McAllister, Iain Wilson
1994-01-01
During the last decade many experimental studies of surface charge phenomena have been undertaken employing right cylindrical spacers. Measurement of the surface charge was performed using small electrostatic field probes to scan across the dielectric surface. Charges are electrostatically induced...
DETERMINATION OF ECONOMIC SIZES FOR RC CYLINDRICAL WATER STORAGE TANKS
Directory of Open Access Journals (Sweden)
Güneş KOZLUCA
2007-03-01
Full Text Available Water storage tanks are built in different shapes and sizes according to needs. Designs of water storage tanks with low costs are quite important for the national economy. Cylindrical and sphere tanks are the most economic types of tanks in terms of material cost. In this study several cylindrical tank designs are made. Then most economic tank radius – tank height ratio is searched by simply changing thickness, height and the radius of the tank considered. Storage capacity of these cylindrical tanks are all the same. All these reinforced tanks have cylindrical reinforced concrete walls fixed at the bottom and free top edge without roof. It is thought that tanks constructed with this optimal ratio will be beneficial.
External Cylindrical Nozzle with Controlled Vacuum
Directory of Open Access Journals (Sweden)
V. N. Pil'gunov
2015-01-01
Full Text Available There is a developed design of the external cylindrical nozzle with a vacuum camera. The paper studies the nozzle controllability of flow rate via regulated connection of the evacuated chamber to the atmosphere through an air throttle. Working capacity of the nozzle with inlet round or triangular orifice are researched. The gap is provided in the nozzle design between the external wall of the inlet orifice and the end face of the straight case in the nozzle case. The presented mathematical model of the nozzle with the evacuated chamber allows us to estimate the expected vacuum amount in the compressed section of a stream and maximum permissible absolute pressure at the inlet orifice. The paper gives experimental characteristics of the fluid flow process through the nozzle for different values of internal diameter of a straight case and an extent of its end face remoteness from an external wall of the inlet orifice. It estimates how geometry of nozzle constructive elements influences on the volume flow rate. It is established that the nozzle capacity significantly depends on the shape of inlet orifice. Triangular orifice nozzles steadily work in the mode of completely filled flow area of the straight case at much more amounts of the limit pressure of the flow. Vacuum depth in the evacuated chamber also depends on the shape of inlet orifice: the greatest vacuum is reached in a nozzle with the triangular orifice which 1.5 times exceeds the greatest vacuum with the round orifice. Possibility to control nozzle capacity through the regulated connection of the evacuated chamber to the atmosphere was experimentally estimated, thus depth of flow rate regulation of the nozzle with a triangular orifice was 45% in comparison with 10% regulation depth of the nozzle with a round orifice. Depth of regulation calculated by a mathematical model appeared to be much more. The paper presents experimental dependences of the flow coefficients of nozzle input orifice
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
A new rigid-plastic/rigid-viscoplastic (RP/RVP) FEM based on linear programming (LP) for plane-strain metal forming simulation is proposed. Compared with the traditional RP/RVP FEM based on iteration solution, it has some remarkable advantages, such as it's free of convergence problem and its convenience in contact, incompressibility constraint and rigid zone treatment. Two solution examples are provided to validate its accuracy and efficiency.
Improved Analysis Techniques for Cylindrical and Spherical Double Probes (Preprint)
2012-03-21
accounts for the finite, but non -negligible extent of the plasma sheath. One of the most extensive assessments of ion collection by a biased cylindrical...Approved for public release; distribution unlimited. 4 regardless of rP/λD so long as the electron distribution function is Maxwellian such that...731. 3 J.G. Laframboise, Theory of Spherical and Cylindrical Langmuir Probes in a Collisionless, Maxwellian Plasma at Rest, (University of Toronto
An Approximate Solution for Spherical and Cylindrical Piston Problem
Indian Academy of Sciences (India)
S K Singh; V P Singh
2000-02-01
A new theory of shock dynamics (NTSD) has been derived in the form of a finite number of compatibility conditions along shock rays. It has been used to study the growth and decay of shock strengths for spherical and cylindrical pistons starting from a non-zero velocity. Further a weak shock theory has been derived using a simple perturbation method which admits an exact solution and also agrees with the classical decay laws for weak spherical and cylindrical shocks.
On elliptic cylindrical Kadomtsev-Petviashvili equation for surface waves
Khusnutdinova, K R; Matveev, V B; Smirnov, A O
2012-01-01
The `elliptic cylindrical Kadomtsev-Petviashvili equation' is derived for surface gravity waves with nearly-elliptic front, generalising the cylindrical KP equation for nearly-concentric waves. We discuss transformations between the derived equation and two existing versions of the KP equation, for nearly-plane and nearly-concentric waves. The transformations are used to construct important classes of exact solutions of the derived equation and corresponding approximate solutions for surface waves.
Cylindrical bubbles and blobs from a Class II Hydrophobin
Russo, Paul; Pham, Michael; Blalock, Brad
2012-02-01
Cerato ulmin is a class II hydrophobin. In aqueous suspensions, it easily forms cylindrical air bubbles and cylindrical oil blobs. The conditions for formation of these unusual structures will be discussed, along with scattering and microscopic investigations of their remarkable stability. Possible applications in diverse fields including polymer synthesis and oil spill remediation will be considered. Acknowledgment is made to Dr. Wayne C. Richards of the Canadian Forest Service for the gift of Cerato ulmin.
Studies of Rigid Rotor-Rigid Surface Scattering in Dynamical Lie Algebraic Method
Institute of Scientific and Technical Information of China (English)
WANG Xiao-Yan; DING Shi-Liang
2004-01-01
The dynamical Lie algebraic method is used for the description of statistical mechanics of rotationally inelastic molecule-surface scattering. It can give the time-evolution operators about the low power of a+ and a by solving a set of coupled nonlinear differential equations. For considering the contribution of the high power of a+ and a, we use the Magnus formula. Thus, with the time-evolution operators we can get the statistical average values of the measurable quantities in terms of the density operator formalism in statistical mechanics. The method is applied to the scattering of N2 (rigid rotor) by a flat, rigid surface to illustrate its general procedure. The results demonstrate that the method is useful for describing the statistical dynamics of gas-surface scattering.
Theory and modeling of cylindrical thermo-acoustic transduction
Energy Technology Data Exchange (ETDEWEB)
Tong, Lihong, E-mail: lhtong@ecjtu.edu.cn [School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, Jiangxi (China); Lim, C.W. [Department of Architecture and Civil Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Zhao, Xiushao; Geng, Daxing [School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, Jiangxi (China)
2016-06-03
Models both for solid and thinfilm-solid cylindrical thermo-acoustic transductions are proposed and the corresponding acoustic pressure solutions are obtained. The acoustic pressure for an individual carbon nanotube (CNT) as a function of input power is investigated analytically and it is verified by comparing with the published experimental data. Further numerical analysis on the acoustic pressure response and characteristics for varying input frequency and distance are also examined both for solid and thinfilm-solid cylindrical thermo-acoustic transductions. Through detailed theoretical and numerical studies on the acoustic pressure solution for thinfilm-solid cylindrical transduction, it is concluded that a solid with smaller thermal conductivity favors to improve the acoustic performance. In general, the proposed models are applicable to a variety of cylindrical thermo-acoustic devices performing in different gaseous media. - Highlights: • Theory and modeling both for solid and thinfilm-solid cylindrical thermo-acoustic transductions are proposed. • The modeling is verified by comparing with the published experimental data. • Acoustic response characteristics of cylindrical thermo-acoustic transductions are predicted by the proposed model.
Comparison of the load-sharing characteristics between pedicle-based dynamic and rigid rod devices
Energy Technology Data Exchange (ETDEWEB)
Ahn, Yoon-Ho [Korea Orthopedics and Rehabilitation Engineering Center, Incheon 403712 (Korea, Republic of); Chen, W-M [Division of Bioengineering, National University of Singapore, Singapore 117576 (Singapore); Lee, Kwon-Yong [Department of Mechanical Engineering, Sejong University, Seoul 143747 (Korea, Republic of); Park, Kyung-Woo [Department of Neurosurgery, Kwang-Hye Spine Hospital, Seoul 135280 (Korea, Republic of); Lee, Sung-Jae [Department of Biomedical Engineering, Inje University, Gimhae 621749 (Korea, Republic of)], E-mail: sjl@bme.inje.ac.kr
2008-12-01
Recently, numerous types of posterior dynamic stabilization (PDS) devices have been introduced as an alternative to the fusion devices for the surgical treatment of degenerative lumbar spine. It is hypothesized that the use of 'compliant' materials such as Nitinol (Ni-Ti alloy, elastic modulus = 75 GPa) or polyether-etherketone (PEEK, elastic modulus = 3.2 GPa) in PDS can restore stability of the lumbar spine without adverse stress-shielding effects that have often been found with 'rigid' fusion devices made of 'rigid' Ti alloys (elastic modulus = 114 GPa). Previous studies have shown that suitably designed PDS devices made of more compliant material may be able to help retain kinematic behavior of the normal spine with optimal load sharing between the anterior and posterior spinal elements. However, only a few studies on their biomechanical efficacies are available. In this study, we conducted a finite-element (FE) study to investigate changes in load-sharing characteristics of PDS devices. The implanted models were constructed after modifying the previously validated intact model of L3-4 spine. Posterior lumbar fusion with three different types of pedicle screw systems was simulated: a conventional rigid fixation system (Ti6Al4V, {phi} = 6.0 mm) and two kinds of PDS devices (one with Nitinol rod with a three-coiled turn manner, {phi} = 4.0 mm; the other with PEEK rod with a uniform cylindrical shape, {phi} = 6.0 mm). To simulate the load on the lumbar spine in a neutral posture, an axial compressive load (400 N) was applied. Subsequently, the changes in load-sharing characteristics and stresses were investigated. When the compressive load was applied on the implanted models (Nitinol rod, PEEK rod, Ti-alloy rod), the predicted axial compressive loads transmitted through the devices were 141.8 N, 109.8 N and 266.8 N, respectively. Axial forces across the PDS devices (Nitinol rod, PEEK rod) and rigid system (Ti-alloy rod) with facet
Kim, Yeonkyu
2003-10-01
A system of differential equations governing the translational and rotational motion of a system model consisting of a rigid satellite and multiple MB suspended rigid flywheels in general configuration is developed. Flywheel modules are contained in a housing rigidly mounted on the satellite and floated by an active MB suspension system, therefore each flywheel module has six degrees of freedom (DOF) as well as the satellite module. Equations of motion for the satellite and flywheels are naturally coupled and the satellite rotational motion and translational motion are coupled. A nonlinear state feedback tracking control law, which is globally asymptotically stable, is developed following a Lyapunov stability theory for integrated power and attitude control using the MB suspended flywheels. The stability, robustness, and tracking and disturbance rejection performance of the present control law with respect to initial attitude error, system modeling error, an imbalance disturbance, is demonstrated by case studies. The satellite departure motion equation derived from the definition of the angular velocity error and the system dynamics equations is presented. Application study of existing power tracking algorithm with this control law shows perfect power tracking for both power charging from and power delivery to the satellite operations and the power tracking can be performed simultaneously with and independent of the attitude control function.
Energy Technology Data Exchange (ETDEWEB)
Denson, R.H.; Bennett, R.D.; Wamsley, R.M.; Bean, D.L.; Ainsworth, D.L.
1987-12-01
The US Army Engineer Waterways Experiment Station (WES) and the US Army Engineer Division, Huntsville (HNDED) have developed general design criteria and specific design review criteria for the below-ground vault (BGV) alternative method of low-level radioactive waste (LLW) disposal. A BGV is a reinforced concrete vault (floor, walls, and roof) placed underground below the frost line, and above the water table, surrounded by filter blanket and drainage zones and covered with a low permeability earth layer and top soil with vegetation. Eight major review criteria categories have been developed ranging from the loads imposed on the BGV structure through material quality and durability considerations. Specific design review criteria have been developed in detail for seven of the eight major categories. 59 refs., 14 figs., 2 tabs.
Regulation of p53 expression and apoptosis by vault RNA2-1-5p in cervical cancer cells.
Kong, Lu; Hao, Qi; Wang, Ying; Zhou, Ping; Zou, Binbin; Zhang, Yu-xiang
2015-09-29
nc886 or VRNA2-1 has recently been identified as a noncoding RNA instead of a vault RNA or a pre-microRNA. Several studies have reported that pre-miR-886 plays a tumor-suppressive role in a wide range of cancer cells through its activity as a cellular protein kinase RNA-activated (PKR) ligand and repressor. However, by sequencing stem-PCR products, we found that a microRNA originating from this precursor, vault RNA2-1-5p (VTRNA2-1-5p), occurs in cervical cancer cells. The expression levels of the predicted targets of VTRNA2-1-5p are negatively correlated with VTRNA2-1-5p levels by quantitative reversion transcription PCR (qRT-PCR). Previous results have shown that VTRNA2-1-5p is overexpressed in human cervical squamous cell carcinomas (CSCCs) compared with adjacent healthy tissues. Inhibition of VTRNA2-1-5p increases Bax protein expression and apoptotic cell death in cervical cancer cells. Our findings suggest that VTRNA2-1-5p has oncogenic activity related to the progression of cervical cancer. Here, we report that VTRNA2-1-5p directly targeted p53 expression and functioned as an oncomir in cervical cancer. VTRNA2-1-5p inhibition decreased cervical cancer cell invasion, proliferation, and tumorigenicity while increasing apoptosis and p53 expression. Interestingly, VTRNA2-1-5p inhibition also increased cisplatin-induced apoptosis of HeLa and SiHa cells. In human clinical cervical cancer specimens, low p53 expression and high VTRNA2-1-5p expression were positively associated.In addition, VTRNA2-1-5p was found to directly target the 5' and 3' untranslated regions (UTRs) of p53. We propose that VTRNA2-1-5p is a direct regulator of p53 and suggest that it plays an essential role in the apoptosis and proliferation of cervical cancer cells.
Energy Technology Data Exchange (ETDEWEB)
Mihailidis, D [CAMC Cancer Center-Alliance Oncology and West Virginia University, Charleston, WV (United States)
2015-06-15
Purpose: To date, there isn’t formal approach for flattening filter-free (FFF) linac vault shielding evaluation, thus, we propose an extension to NCRP#151 to accommodate the recent large number of FFF linac installations.Methods and Materials: We extended the approach in NCRP#151 to design two Truebeam vaults in our new cancer center for hypofractionated treatments. Monte Carlo calculations have characterized primary, scattered, leakage and neutron radiations from FFF-modes. These calculations have shown that: a) FFF primary beam is softer on the central-axis compared to flattening filtered (FF), b) the lateral dose profile is peaked on the central axis and less integral target current is required to generate the same tumor dose with the FF beam. Thus, the TVLs for FFF mode are smaller than those of the FF mode and the scatter functions of the FF mode (NCRP#151) may not be appropriate for FFF-mode, c) the neutron source strength and fluence for 18X-FFF is smaller than 18X-FF, but it is not of a concern here, no 18X-FFF-mode is available on the linac under investigation. Results: These barrier thickness are smaller (12% reduction on the average) than those computed for conventional FF mode with same realistic primary workload since, the primary TVLs used here are smaller and the WL is smaller than the conventional (almost half reduced), keeping the TADR in tolerance. Conclusions: A comprehensive method for shielding barrier calculations based on dedicated data for FFF-mode linacs is highly desired. Meanwhile, we provide an extension to NCRP#151 to accommodate the shielding design of such installations. It is also shown that if a vault is already designed for IMRT/VMAT and SABR hypofractionated treatments with FFF-mode linac, the vault can also be used for a FFF mode linac replacement, leaving some leeway for slightly higher workload on the FFF linac.
Degeneration, Rigidity and Irreducible Components of Hopf Algebras
Institute of Scientific and Technical Information of China (English)
Abdenacer Makhlouf
2005-01-01
The aim of this work is to discuss the concepts of degeneration, deformation and rigidity of Hopf algebras and to apply them to the geometric study of the varieties of Hopf algebras. The main result is the description of the n-dimensional rigid Hopf algebras and the irreducible components for n ＜ 14 and n = p2 with p a prime number.
Non-rigid registration by geometry-constrained diffusion
DEFF Research Database (Denmark)
Andresen, Per Rønsholt; Nielsen, Mads
2001-01-01
Assume that only partial knowledge about a non-rigid registration is given: certain points, curves, or surfaces in one 3D image are known to map to certain points, curves, or surfaces in another 3D image. In trying to identify the non-rigid registration field, we face a generalized aperture problem...
Non-rigid image registration using bone growth model
DEFF Research Database (Denmark)
Bro-Nielsen, Morten; Gramkow, Claus; Kreiborg, Sven
1997-01-01
Non-rigid registration has traditionally used physical models like elasticity and fluids. These models are very seldom valid models of the difference between the registered images. This paper presents a non-rigid registration algorithm, which uses a model of bone growth as a model of the change b...
Rigid Body Motion in Stereo 3D Simulation
Zabunov, Svetoslav
2010-01-01
This paper addresses the difficulties experienced by first-grade students studying rigid body motion at Sofia University. Most quantities describing the rigid body are in relations that the students find hard to visualize and understand. They also lose the notion of cause-result relations between vector quantities, such as the relation between…
Reinforced molecular recognition as an alternative to rigid receptors
Otto, Sijbren
2006-01-01
In theory, a perfectly rigid receptor will probably be an unbeatable binder. However, rigidity may not be easy to achieve in practice and it is certainly not Nature’s method to realise high affinity. In many proteins binding affinity is increased through non-covalent interactions within the protein.
Quadratic Twists of Rigid Calabi–Yau Threefolds Over
DEFF Research Database (Denmark)
Gouvêa, Fernando Q.; Kiming, Ian; Yui, Noriko
2013-01-01
We consider rigid Calabi–Yau threefolds defined over Q and the question of whether they admit quadratic twists. We give a precise geometric definition of the notion of a quadratic twists in this setting. Every rigid Calabi–Yau threefold over Q is modular so there is attached to it a certain newfo...
Stability of rigid body rotation from a bond graph perspective
Breedveld, Peter
2009-01-01
This paper describes the history of the bond graph description of rigid body rotation dynamics and resolves a paradox that resulted from the common Euler Junction Structure (EJS) description of the exterior product in the Newton–Euler equation describing rigid body rotation [D.C. Karnopp, R.C. Rosen
Mitri, F G
2016-01-01
Analytical expressions for the axial and transverse acoustic radiation forces as well as the radiation torque per length are derived for a rigid elliptical cylinder placed arbitrarily in the field of in plane progressive, quasi-standing or standing waves. The rigid elliptical cylinder case is important to be considered as a first-order approximation of the behavior of a fluid particle suspended in air, because of the significant acoustic impedance mismatch at the particle's boundary. Based on the partial-wave series expansion method in cylindrical coordinates, non-dimensional acoustic radiation force and torque functions are derived and defined in terms of the scattering coefficients of the elliptic cylinder. A coupled system of linear equations is obtained after applying the Neumann boundary condition for an immovable surface in a non-viscous fluid, and solved numerically by matrix inversion after performing a single numerical integration procedure. Computational results for the non-dimensional force compone...
Tautochrone and Brachistochrone Shape Solutions for Rocking Rigid Bodies
Glaschke, Patrick
2016-01-01
Rocking rigid bodies appear in several shapes in everyday life: As furniture like rocking chairs and rocking cradles or as toys like rocking horses or tilting dolls. The familiar rocking motion of these objects, a non-linear combination of a rigid rotation and a translation of the center of mass, gives rise to a number of interesting dynamical properties. However, their study has received little attention in the literature. This work presents a comprehensive introduction to the dynamics of rocking rigid bodies, including a concise derivation of the equations of motion as well as a general inversion procedure to construct rocking rigid body shapes with specified dynamical properties. Moreover, two novel rigid body shapes are derived - the tautochrone shape and the brachistochrone shape - which represent an intriguing generalization of the well-know tautochrone and brachistochrone curves. In particular, tautochrone shapes offer an alternative construction of a tautochrone pendulum, in addition to Huygens' cyclo...
Rigidity-Preserving Team Partitions in Multiagent Networks.
Carboni, Daniela; Williams, Ryan K; Gasparri, Andrea; Ulivi, Giovanni; Sukhatme, Gaurav S
2015-12-01
Motivated by the strong influence network rigidity has on collaborative systems, in this paper, we consider the problem of partitioning a multiagent network into two sub-teams, a bipartition, such that the resulting sub-teams are topologically rigid. In this direction, we determine the existence conditions for rigidity-preserving bipartitions, and provide an iterative algorithm that identifies such partitions in polynomial time. In particular, the relationship between rigid graph partitions and the previously identified Z-link edge structure is given, yielding a feasible direction for graph search. Adapting a supergraph search mechanism, we then detail a methodology for discerning graphs cuts that represent valid rigid bipartitions. Next, we extend our methods to a decentralized context by exploiting leader election and an improved graph search to evaluate feasible cuts using only local agent-to-agent communication. Finally, full algorithm details and pseudocode are provided, together with simulation results that verify correctness and demonstrate complexity.