New Method For Structural Analysis Research Articles

New method of structural analysis and measurement of V-shaped percussion cracks in quartz sands surface by confocal laser scanning microscope (CLSM)

Microtextures of quartz sand grains can be used to establish sedimentary provenance of sedimentary deposits. V-shaped percussion cracks (Vs), which are randomly produced by grain-to-grain mechanical collision in high-energy subaqueous environments, are significant microtextures used for investigation of fluvial and marine sediment. In previous studies, others have used the percentage of microtextures obtained by scanning electron microscope to compare sediment samples. We developed a new method of measurement and evaluation of the surface of quartz grains using a confocal laser scanning microscope (CLSM) and applied the method to coastal sands containing quartz grains with abundant Vs. The method using international-standard surface-roughness parameters (ISO 25178) is useful for evaluating surface textures of quartz grains and for quantifying the structures of Vs (such as aperture area, density, and depth). The results of applying the method to coastal sands suggest that the density of Vs related to the coastal geological setting, that the depth of Vs related to wave height and offshore gradient, and that the size of Vs was not influenced by grain size or mineral composition of the coastal sands. This new method can corroborate preceding methods in provenance study of quartz grains in subaqueous environments. In principle, it also could apply to other types of microtextures and other minerals, such as degrees of weathering on surfaces of heavy minerals. This method, using a CLSM, has the potential to be applied to various provenance studies using grain-surface texture.

Determination of Crack Pattern in Concrete Structures Using Applied Element Method

Applied Element Method (AEM) is a relatively new method for structural analysis developed by Kimiro Meguro and Hatem Tagel Din in 1997. It can capture the behavior of structure up to failure. In this method, structure is discretized into rigid elements connected by springs. The stiffness matrix of the structure consists of that of springs only. Here, the method is used to find out the failure load and predict the crack propagation. Two methods are available to determine the crack pattern namely unloading-reloading method and residual force method. These approaches are used to maintain equilibrium during the process of cracking. In this paper, these methods are discussed and they are used for the analysis of plain concrete beams with different support conditions.

In-depth characterization of icosahedral ordering in liquid copper

The presence of icosahedral ordering in liquid copper at temperatures close to the melting point is now well-established both experimentally and through computer simulation. However, a more elaborate analysis of local icosahedral and icosahedron-like structures, together with a system for classifying such structures based on some measure of “icosahedrity”, has so far been conspicuously absent in the literature. Similarly, the dynamics of these structures has not yet received the attention it merits.We present a new method for structural analysis, which combines Voronoi analysis with bond-orientational order parameters, and apply it to liquid Cu configurations obtained from tight-binding molecular dynamics at a range of temperatures near the melting point. We introduce a clear system for classifying local structures according to their degree of similarity to the perfect icosahedron, and show how their energies of formation correlate with our structural descriptor. We examine the frequencies of occurrence for the classes of Voronoi polyhedra we distinguish, calculate their lifetimes, and establish the temperature dependence of these properties. We explore the dynamics of icosahedron-like structures by examining how individual classes transform between one another. Finally, we perform structural correlation analysis, demonstrating, among other things, that icosahedra and icosahedron-like structures preferentially connect and show a tendency towards clustering. We believe our approach can be readily applied in studies of icosahedral ordering in liquid metals or metallic glasses.

PRESSURE OF SATURATED STEAMS AS INDICATOR OF STRUCTURAL CHANGES IS IN LIQUIDS

The results show that the pressure of saturated vapors of water and other molecular liquids can indeed be affected by structural changes in the volume and even on the surface. On the basis of supposition that homogeneously structured liquids have permanent energy of activating, two functions are shown out: cubic - for pressure of saturated steams ( ∛ Р =f (T)) and square - for a surface-tension waters ( √σ = f (T)) that can keep straightforwardness in the termobaric terms of existence of corresponding structures. Calculations have showed that the first function well described 4-phase changes of water structure at heating to 374 °C and it is suitable for the analysis of in other molecular liquids. The second function confirms homogeneity of structures of interface surface in waters of I and II types. For liquids with weak intermolecular interaction, only two types of volume structuring were found — before and after the boiling point. In this case, high-temperature structures are always homogeneous, and low-temperature structures can be homogeneous (C2H6, СН3Cl) or non-uniform (СН3ОН, CCl4). It is noted that the existence of high-temperature structures for the liquids under consideration is not due to temperature, but to high pressures, which have to be used to preserve these substances in a liquid state. It is well-proven by means of cubic function that in the concentrated solutions of Н2SO4 below 40 °С it is possible to find out the presence of hydrates of H 2 SO 4 ⸱6,5Н 2 О, H 2 SO 4 ⸱4Н 2 О, H 2 SO 4 ⸱3Н 2 О і H 2 SO 4 ⸱2Н 2 О. The character of structurizing of water in salt solutions to 100 °С, as a rule, remains immutable. But in saturated solutions of KNO 3 over 50 °С there is formation of some homogeneous structure of water. The results show that salts can change the structure of water only in cases of high concentrations and special properties of their ions. Using the cubic function of the saturated vapor pressure can be a new method for structural analysis of liquids. This method can be especially useful in the study of systems with H-bonds, as well as in the case of salt solutions that can form crystalline hydrates.

Identification of Global and Local Shocks in International Financial Markets via General Dynamic Factor Models*

AbstractWe employ a two-stage general dynamic factor model to analyze co-movements between returns and between volatilities of stocks from the U.S., European, and Japanese financial markets. We find two common shocks driving the dynamics of volatilities—one global shock and one United States–European shock—and four local shocks driving returns, but no global one. Co-movements in returns and volatilities increased considerably in the period 2007–2012 associated with the Great Financial Crisis and the European Sovereign Debt Crisis. We interpret this finding as the sign of a surge, during crises, of interdependencies across markets, as opposed to contagion. Finally, we introduce a new method for structural analysis in general dynamic factor models which is applied to the identification of volatility shocks via natural timing assumptions. The global shock has homogeneous dynamic effects within each individual market but more heterogeneous effects across them, and is useful for predicting aggregate realized volatilities.

Identification of Global and National Shocks in International Financial Markets Via General Dynamic Factor Models

We employ a two-stage general dynamic factor model to analyze co-movements between returns and between volatilities of stocks from the US, European, and Japanese financial markets. We find two common shocks driving the dynamics of volatilities – one global shock and one US-European shock – and four local shocks driving returns, but no global one. Co-movements in returns and volatilities increased considerably in the period 2007-2012 associated with the Great Financial Crisis and the European Sovereign Debt Crisis. We interpret this finding as the sign of a surge, during crises, of interdependencies across markets, as opposed to contagion. Finally, we introduce a new method for structural analysis in general dynamic factor models which is applied to the identification of volatility shocks via natural timing assumptions. The global shock has homogeneous dynamic effects within each individual market but more heterogeneous effects across them, and is useful for predicting aggregate realized volatilities.

Change Analysis in Structural Laser Scanning Point Clouds: The Baseline Method.

A method is introduced for detecting changes from point clouds that avoids registration. For many applications, changes are detected between two scans of the same scene obtained at different times. Traditionally, these scans are aligned to a common coordinate system having the disadvantage that this registration step introduces additional errors. In addition, registration requires stable targets or features. To avoid these issues, we propose a change detection method based on so-called baselines. Baselines connect feature points within one scan. To analyze changes, baselines connecting corresponding points in two scans are compared. As feature points either targets or virtual points corresponding to some reconstructable feature in the scene are used. The new method is implemented on two scans sampling a masonry laboratory building before and after seismic testing, that resulted in damages in the order of several centimeters. The centres of the bricks of the laboratory building are automatically extracted to serve as virtual points. Baselines connecting virtual points and/or target points are extracted and compared with respect to a suitable structural coordinate system. Changes detected from the baseline analysis are compared to a traditional cloud to cloud change analysis demonstrating the potential of the new method for structural analysis.

Wind-induced vibrations of structures using design spectra

This paper discusses the estimation of wind dynamic response of two types of structures by following classical and novel approaches. A new method for structural analysis based on wind design spectra is introduced and tested against simulated and experimental data. Design spectra are derived from the dynamic response of a group of oscillators subject to wind, using similar techniques than those used to derive design spectra for seismic engineering applications. The method is used on three chimneys of different height as well as on a regular building which has been experimentally tested in the past. The chimneys and building are also submitted to simulated wind fields to provide additional sets of results. It is observed that the spectral approach is consistent with experimental and simulated results and therefore is concluded that design spectra can cover broad range of practical applications.

Loos: A Toolkit for Analyzing Molecular Simulations and Making New Tools

We have developed LOOS (Lightweight Object Oriented Structure-analysis) as a tool for making new tools to analyze molecular simulations. LOOS is an object-oriented library designed to facilitate the rapid development of new methods for structural analysis. LOOS is written in C++ and is easily extensible, only requiring knowledge of 4 core classes. A Python interface is also available, further facilitating rapid development of analysis tools and broadening the LOOS community. LOOS reads the native file formats of most common simulation packages and can write NAMD formats (PDB and DCD) and Gromacs XTC. A dynamic atom selection language, based on C expression syntax, is included and is easily accessible via a single function call. LOOS includes over 140 pre-built tools for common structural analysis tasks, including analyzing simulation convergence, 3D histograms, and elastic network models. Python-based packages include the optimal membrane generator and tools for the Voronoi tesselation of membranes. In addition, tool templates for common analysis work-flows are included to facilitate the development of new tools. LOOS is available for download at http://loos.sourceforge.net and is distributed under the GPLv3 license.

Structure-Correlation NMR Spectroscopy for Macromolecules Using Repeated Bidirectional Photoisomerization of Azobenzene.

Control over macromolecular structure offers bright potentials for manipulation of macromolecular functions. We here present structure-correlation NMR spectroscopy to analyze the correlation between polymorphic macromolecular structures driven by photoisomerization of azobenzene. The structural conversion of azobenzene was induced within the mixing time of a NOESY experiment using a colored light source, and the reverse structural conversion was induced during the relaxation delay using a light source of another color. The correlation spectrum between trans- and cis-azobenzene was then obtained. To maximize the efficiency of the bidirectional photoisomerization of azobenzene-containing macromolecules, we developed a novel light-irradiation NMR sample tube and method for irradiating target molecules in an NMR radio frequency (rf) coil. When this sample tube was used for photoisomerization of an azobenzene derivative at a concentration of 0.2 mM, data collection with reasonable sensitivity applicable to macromolecules was achieved. We performed isomerization of an azobenzene-cross-linked peptide within the mixing time of a NOESY experiment that produced cross-peaks between helix and random-coil forms of the peptide. Thus, these results indicate that macromolecular structure manipulation can be incorporated into an NMR pulse sequence using an azobenzene derivative and irradiation with light of two types of wavelengths, providing a new method for structural analysis of metastable states of macromolecules.

確率有限要素法による形状不確定性を考慮した構造解析手法について

A new method of structural analysis is proposed for the solution of problems of response uncertainty for the case that involves uncertainty in shape. The method makes use of a Hermite polynomial chaos expansion of the process. The proposed method involves a mathematical formulation which is a natural extension of the deterministic finite element concept to the space of random functions. In this paper, two example problems are investigated by the new method, i.e., a plate with a circular hole at the center and a cruciform weld joint. Then accuracy of the analysis will be discussed for different size of a plate with a circular hole. The validity of a new method of structural analysis is discussed using a result of uncertainty analysis through a Monte-Carlo simulation by solution of the deterministic problems.

LOOS: A Tool for Making New Tools for Analyzing Molecular Simulations

We have developed LOOS (Lightweight Object Oriented Structure-analysis) as a tool for making new tools to analyze molecular simulations. LOOS is an object-oriented library designed to facilitate the rapid development of new methods for structural analysis. LOOS includes over 130 pre-built tools for common structural analysis tasks, including analyzing simulation convergence, 3D histograms, and elastic network models. LOOS supports reading the native file formats of most common simulation packages and can write NAMD formats (PDB and DCD) and Gromacs XTC. A dynamic atom selection language, based on C expression syntax, is included and is easily accessible via a single function call. LOOS is written in C++ and makes extensive use of Boost and the Standard Template Library. Through modern C++ design, LOOS is both simple to use (requiring knowledge of only 4 core classes and a few utility functions) and easily extensible. A Python interface to the core components of LOOS is also available, further facilitating rapid development of analysis tools and broadening the LOOS community by making it accessible to those who would otherwise be deterred by using C++. LOOS is available for download at http://loos.sourceforge.net

Loos: A Tool for Making New Tools for Analyzing Molecular Simulations

We have developed LOOS (Lightweight Object Oriented Structure-analysis) as a tool for making new tools for analyzing molecular simulations. LOOS is an object-oriented library written in C++ with a Python interface and was designed to facilitate the rapid development of new methods for structural analysis in either C++ or Python. In addition, LOOS includes over 130 pre-built tools for common structural analysis tasks including 3D histograms for visualization, hydrogen bonding patterns, and assessing simulation convergence. LOOS also includes a set of libraries and tools for performing elastic network model calculations. LOOS supports reading the native file formats of most common simulation packages, such as Amber (including NetCDF-formatted), CHARMM, Gromacs, NAMD, and Tinker. LOOS can also write NAMD formatted PDB and DCD files. A dynamic atom selection language, based on the C expression syntax, is included in the library and is easily accessible to the tool writer. Through modern C++ design, LOOS is both simple to use, requiring knowledge of only 4 core classes, and easy to extend. LOOS makes extensive use of Boost and the Standard Template Library for correctness and ease of use, and relies on ATLAS for high performance numerical routines.

Loos: A Tool for Making New Tools for Analyzing Molecular Simulations

We have developed LOOS (Lightweight Object Oriented Structure-analysis) as a tool for making new tools for analyzing molecular simulations. LOOS is an object-oriented library designed to facilitate the rapid development of new methods for structural analysis. LOOS includes over 120 pre-built tools for common structural analysis tasks, such as assessing the convergence of simulations, hydrogen bonding patterns, and the construction and visualization of 3D histograms as density. LOOS supports reading the native file formats of most common simulation packages, including AMBER, CHARMM, Gromacs, NAMD, and Tinker and can write NAMD formats (PDB and DCD). A dynamic atom selection language, based on the C expression syntax, is included as part of the library and is easily accessible to both the programmer and the end user. LOOS is written in C++ and makes extensive use of Boost and the Standard Template Library. Through modern C++ design, LOOS is both simple to use (requiring knowledge of only 4 core classes and a few utility functions) and easily extensible. A Python interface to the core components of LOOS is also available, further facilitating rapid development of analysis tools and broadening the LOOS community by making it accessible to those who would otherwise be deterred by using C++. LOOS also includes a set of libraries and tools for performing elastic network model calculations that are easily extended to accommodate new methods.

A theoretical‐experimental approach for assessing the vibration impact due to vehicular traffic upon the heritage building structures

In past years, a new method of structural analysis has been developed for assessing the vibration impact due to vehicular traffic upon the heritage building structures. This method is based on on the conjuncture among the monitoring of the structure, and the structural identification. The satisfaction of such demands in the case of buildings already realized, above all if ancient, can be prevented by the impossibility to reach to a complete knowledge both of the structural organism and the strength state of maintenance of every component of the building. An exhaustive knowledge would be achievable only applying such methods of investigation to induce heavy troubles to the analyzed manufactured article. From these consideration the idea of the construction of an elementary system is born. An elementary PC model, that is an ideal receiver whose all the mechanical and geometric characteristics are known, has been designed for in situ analysis and excited applying the experimental vibrational levels in order to evaluate the response. A further development is to realize the physical model and execute local experimental campaigns. This operative system has to be transportable and positionable near the source without holding up the traffic nor damaging the measurement site.

Characterization of cisplatin adducts of oligonucleotides by fast atom bombardment mass spectrometry

The products of the reaction of the antitumor drug cisplatin ( cis-diamminedichloroplatinum(II)) with four oligonucleotide tetramers, d(GpCpGpC), d(GpGpCpC), d(TpGpApT), and d(TpGpCpT), were separated by gel permeation chromatography and characterized by negative- and positive-ion fast atom bombardment (FAB) mass spectrometry. Fragment ions indicating the oligonucleotide sequence and the position of cisplatin binding were observed in MS/MS spectra following collisional activation and B/E-linked scanning. Positive-ion FAB MS/MS spectra were characterized by platinum-containing product ions. Nonplatinated sequence ions and internal fragment ions were present primarily in the negative-ion spectra. The most prominent fragment ions containing platinum were [HB 2·Pt·B 3H] + and [HB 1·Pt·B 2H] +, where B 1, B 2, and B 3 were bases in the oligonucleotide tetramer, one of which was usually guanine. Both singly and doubly charged platinum complexes were observed, probably indicating reduction of Pt(II) during the FAB ionization process. The location of the platinum complex bound to each oligonucleotide sequence could be determined, and the binding sites observed by mass spectrometry were similar to those previously determined by other methods. FAB ionization with collisional activation and MS/MS analysis could serve as a new method for structural analysis of platinated oligonucleotides.

Low-Energy Atom Scattering from Surfaces

Experiments in which low-energy atoms are scattered from surfaces represent an important new method for structural analysis of the topmost atomic layers of a surface. The method and its application in a number of areas in surface science, such as detecting surface defects and studying lattice dynamics, are discussed.

Determination of functional groups of coal-derived liquids by n.m.r. and elemental analysis

A new method of structural analysis was applied to a group of hydroliquefied coal samples. The method uses elemental analysis and n.m.r. data to estimate the concentrations of functional groups in the samples. The samples included oil and asphaltene fractions obtained in a series of hydroliquefaction experiments, and a set of nine fractions separated from a coal-derived oil. The structural characterization of these samples demonstrates that estimates of functional group concentrations can be used to provide detailed structural profiles of complex mixtures and to obtain limited information about reaction pathways.

Some Applications of a New Method of Structural Analysis by Infrared Spectroscopy

Some Applications of a New Method of Structural Analysis by Infrared Spectroscopy

SPHERICAL HARMONIC DEFORMATION

A radically new method of structural analysis is proposed which relates the deformation of all rocks to a three‐dimensional model of close‐packed spheres and deformation ellipsoids. All rocks exist under variable stress conditions and are deformed, but the principles of three‐dimensional deformation are poorly understood by many geologists and geophysicists. An understanding of rock deformation in three dimensions is a very valuable aid in geological interpretation and in the search for hydrocarbons. The method proposed provides the geologist, geophysicist and associated scientific disciplines with a means of understanding complex, three‐dimensional deformation and attempts to explain all deformational phenomena from mud cracks to plate tectonics. Deformation is a spherical harmonic waveform which, although complex in detail, is intrinsically no more mathematically complicated than the reciprocal of the square root of three. The analysis is illustrated by examples of “compressive” deformation from the Tertiary fold belt of Spitsbergen and the “tensional” or “gravitational” deformation in the Viking Graben of the Northern North Sea.