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Search Results: 1 - 10 of 1822 matches for " structures "
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Representations of Each Number Type That Differ by Scale Factors  [PDF]
Paul Benioff
Advances in Pure Mathematics (APM) , 2013, DOI: 10.4236/apm.2013.34057
Abstract: For each type of number, structures that differ by arbitrary scaling factors and are isomorphic to one another are described. The scaling of number values in one structure, relative to the values in another structure, must be compensated for by scaling of the basic operations and relations (if any) in the structure. The scaling must be such that one structure satisfies the relevant number type axioms if and only if the other structure does.
Circular Natural Geoforms, Sierras Pampeanas, Argentina  [PDF]
Adolfo Antonio Gutiérrez, Ricardo Mon, Clara Eugenia Cisterna
Open Journal of Geology (OJG) , 2017, DOI: 10.4236/ojg.2017.79086
Abstract: We describe two circular morphological features representing depressed areas. This preliminary work is based on visual interpretations from Landsat ETM satellite images and SRTM Radar scans. The two geoforms are located at the north of the Sierras Pampeanas in Argentina. The La Ciénaga circular indentation is 15 km in diameter and Las Cejas is 34 km in diameter. Until now rings of these characteristics, magnitudes and diameters are unknown and unheard of in Argentina.
Improvement of Cylindrical Cloak by Layered Structure of Homogeneous Isotropic Materials  [PDF]
Jun DING, Yang LIU, Chenjiang GUO, Qian XU
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2009, DOI: 10.4236/jemaa.2009.14035
Abstract: The perfect cylindrical cloak requires three spatial variant material parameters, which is very difficult to realize in practice [Science 312, 1780 (2006)]. The approach of realizing the electromagnetic cloaking by concentric layered structures instead of using the metamaterial was presented [Optics Express, Vol. 15, No. 18 (2007)]. We use the concentric layered structures to realize a simplified cylindrical cloak with improved parameters and an ideal cylindrical cloak with spatially invariant axial material parameters. Numerical simulation results validate that cloaking performance is significantly improved compared with previously proposed multilayered cloak.
Nonlinear Interaction of N Conservative Waves in Two Dimensions  [PDF]
Victor A. Miroshnikov
American Journal of Computational Mathematics (AJCM) , 2014, DOI: 10.4236/ajcm.2014.43012
Abstract:

Kinematic Fourier (KF) structures, exponential kinematic Fourier (KEF) structures, dynamic exponential (DEF) Fourier structures, and KEF-DEF structures with constant and space-dependent structural coefficients are developed in the current paper to treat kinematic and dynamic problems for nonlinear interaction of N conservative waves in the two-dimensional theory of the Newtonian flows with harmonic velocity. The computational method of solving partial differential equations (PDEs) by decomposition in invariant structures, which continues the analytical methods of undetermined coefficients and separation of variables, is extended by using an experimental and theoretical computation in Maple?. For internal waves vanishing at infinity, the Dirichlet problem is formulated for kinematic and dynamics systems of the vorticity, continuity, Helmholtz, Lamb-Helmholtz, and Bernoulli equations in the upper and lower domains. Exact solutions for upper and lower cumulative flows are discovered by the experimental computing, proved by the theoretical computing, and verified by the system of Navier-Stokes PDEs. The KEF and KEF-DEF structures of the cumulative flows are visualized by instantaneous surface plots with isocurves. Modeling of a deterministic wave chaos by aperiodic flows in the KEF, DEF, and KEF-DEF structures with 5N parameters is considered.

Theoretical and Comparative Study of the Complex [RuCl3(H2O)2(Gly)] by Density Functional Theory  [PDF]
Kátia Meirelles D. de Sousa, Marcio Adriano S. Chagas, Jesyca Mayra F. D. dos Santos, Anderson D. Galv?o, Fabrício Tarso de Moraes, Andressa Teixeira Barros Nunes Ribeiro, Dário Batista Fortaleza, Kelly Aparecida da Encarna??o Amorim, Wagner B. dos Santos
Open Journal of Inorganic Chemistry (OJIC) , 2018, DOI: 10.4236/ojic.2018.81004
Abstract: In this work, the use of computational methods was essential to distinguish the three possible isomeric structures of the [RuCl3(H2O)2(Gly)] molecule. The characterization of these molecules was performed using IR, NMR and UV-VIS simulations. Some calculations related to the optimization of structures and properties such as chemical hardness and dipole moment were also conducted. The fac-cis isomer presented promising data when compared to the experimental data, indicating that this is the likely experimentally synthesized isomer. This study demonstrates the technical utility of the computational calculations by virtue of situations that prevent the realization of X-ray diffraction.
Cubiertas para vi?edos
Fernández,Teodoro; García,Pilar; Courard,Paulina;
ARQ (Santiago) , 2003, DOI: 10.4067/S0717-69962003005400012
Abstract: a world of limited resources and technologies in a friendly climate is explored in this joint workshop between the pontificia universidad católica in chile and lima's universidad ricardo palma. the challenge was to develop a constructive system to create shade in three vineyards south of santiago, using wood in small dimensions and simple assembly techniques
Estudo teórico experimental de liga??es "T" e "KT", em perfis tubulares de a?o
Mendes, Francisco Canazart;Freitas, Marcilio Sousa da Rocha;Freitas, Arlene Maria Sarmanho;
Rem: Revista Escola de Minas , 2012, DOI: 10.1590/S0370-44672012000200005
Abstract: this work presents a study of welded t and kt gap joints, formed by a seamless hollow section with rectangular hollow chord sections and circular hollow sections for the members. the developed study considers theoretical and numerical analyses for the joints, experimental tests in full scale prototypes, and tests for residual stress in the rectangular hollow section. the experimental results were used in order to obtain the overall joint behavior, ultimate load, and collapse mode. the numerical analysis using finite elements methods involved the generation, testing and calibration of the experimental results. the model represents the behavior and load capacity of the tested joints. the numerical models considered or not the welding and geometric imperfections and the results were compared with the experimental data. the accomplished analyses present good correlation with the experimental results.
Behaviour of a Composite Concrete-Trapezoidal Steel Plate Slab in Fire  [PDF]
Toma? Hozjan, Miran Saje, Igor Planinc, Stanislav Srp?i?, Sebastjan Bratina
Engineering (ENG) , 2010, DOI: 10.4236/eng.2010.28076
Abstract: The present paper investigates fire resistance of a simply-supported composite concrete-trapezoidal steel sheet slab. The objective is to find out if a steel sheet, as a moisture diffusion barrier, may substantially effect the hydro-thermal situation in the concrete part of the cross-section. The numerical integration of the equations of a coupled hygro-thermal boundary-value problem (Tenchev, R.T., Li, L.Y. and Purkiss, J.A. (2001) Num. Heat Transfer Part A, 39(7), 685-710), with and without considering the barrier, shows that the barrier does not really effect the magnitude and the development of temperatures over the cross-section, while there is a significant effect on the pattern of moisture transport and the magnitude of vapour pressure. Particularly high magnitudes of vapour pressure (about 4.5 MPa) were shown in cases where the steel sheet was considered in analyses, which indicates a possible micro damage of concrete in the web of the section, although spalling probably cannot take place due to the steel sheet cover. As the typical composite slab investigated here is not sufficiently fire resistant without any additional reinforcement bars placed in the web, further in-vestigations are directed to finding an optimal position and area of these bars. Following a simplified procedure given in EC2 (Eurocode 2, Design of Concrete Structures, Part 1.2 (2004) Structural fire design, European Committee for Standardization) and assuming that the present composite slab is subject to the uniform traction , yields that placing one bar with the area 1.153 cm2 4 cm away from the edge suffices for the 60 min fire resistance of the slab.
Thermodynamic Formulation of Living Systems and Their Evolution  [PDF]
Luis Felipe del Castillo, Paula Vera-Cruz
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.25047
Abstract: The purpose of this review article is to present some of the recent contributions that show the use of thermo-dynamics to describe biological systems and their evolution, illustrating the agreement that this theory pre-sents with the field of evolution. Organic systems are described as thermodynamic systems where entropy is produced by the irreversible processes, considering as an established fact that this entropy is eliminated through their frontiers to preserve life. The necessary and sufficient conditions to describe the evolution of life in the negentropy principle are established. Underlining the fact that the necessary condition requires formulation, which is founded on the principle of minimum entropy production for open systems operating near equilibrium. Other formulations are mentioned, particularly the information theory, the energy inten-siveness hypothesis and the theory of open systems far from equilibrium. Finally suggesting the possibility of considering the lineal formulation as a viable alternative; that is, given the internal constrictions under which a biological system operates, it is possible that the validity of its application is broader than it has been suggested.
Structures, Fields and Methods of Identification of Nonlinear Static Systems in the Conditions of Uncertainty  [PDF]
Nikolay Karabutov
Intelligent Control and Automation (ICA) , 2010, DOI: 10.4236/ica.2010.12007
Abstract: The field of structures on set of secants is offered and methods of its construction for various classes of one-valued nonlinearities of static systems are considered. The analysis of structural properties of system is fulfilled on specially generated set of data. Representation on which modification it is possible to judge to nonlinear structure of static systems is introduced. It is shown, that structures of nonlinear static systems have a special V-point. The adaptive algorithm of an estimation of structure of nonlinearity on a class poly-nomial function is offered.
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