Analysis Of Internal Structure Research Articles

Geochemical constraints on the seismic properties of the lunar mantle

Abstract Thermodynamic modeling of phase relations and physical properties in the Na2O–TiO2–CaO–FeO–MgO–Al2O3–SiO2–Fe–FeS system and a Monte-Carlo inversion procedure have been used to calculate the density and velocity distribution in the mantle, and core radii of the Moon from the mass and moment of inertia constraints from recent Lunar Prospector gravity measurements. For the computation of the phase diagram for a given chemical composition, we have used a method of minimization of the total Gibbs free energy and self-consistent thermodynamic data for minerals and solid solutions. For the crustal thickness and density of 60 km and 3.0 g cm−3, the largest core radii are estimated to be 530 km for an FeS (troilite)-core (4.1% of total mass), 490 km for a eutectic Fe–FeS-core (3.4%), 445 km for an Fe–10 wt.% S-core (2.9%), and 350 km for an Fe-core (2%). The existence of an Fe–FeS-core of intermediate radius of 250–400 km is compatible with recent lunar core information and lend support to a chemically stratified lunar mantle. The sensitivity of density and seismic velocities to temperature, pressure and composition variations is examined. The modeling results indicate that we can determine the permissible density and velocity ranges in the zoned lunar mantle with confidence. The maximum and minimum density changes at depths of the lunar mantle, consistent with geochemical constraints and mass and moment of inertia requirements, are found to be: 3.22 g cm −3 ≤ρ≤3.44 g cm−3 at depths of 60–500 km and 3.34 g cm −3 ≤ρ≤3.52 g cm−3 at depths between 500 km and the core mantle boundary. Core-free models of the Moon are possible only if the lower mantle densities are between 3.49 and 3.52 g cm−3 ( 20 wt .% FeO wt.%). The calculated field of seismic velocities in the zoned lunar mantle shows that over a broad range of mantle compositions, temperatures, and densities the maximum variations are as follows: 4.23 km s −1 ≤V S ≤4.69 km s−1 and 7.41 km s −1 ≤V P ≤8.24 km s−1 at depths of 60–500 km, and 4.24 km s −1 ≤V S ≤4.64 km s−1 and 7.63 km s −1 ≤V P ≤8.39 km s−1 at depths between 500 km and the core mantle boundary. These petrologically and geophysically admissible ranges of velocities and densities may constitute a significant constraint for the analysis of internal structure of the Moon using the Apollo seismic data.

Application of the International Cooperative Ataxia Scale rating in multiple system atrophy.

We assessed the International Cooperative Ataxia Scale (ICARS) as a means of extracting and rating cerebellar signs in multiple system atrophy (MSA). Cross-sectional analysis of internal consistency, factor structure, and correlation with parkinsonism severity (Unified Parkinson's Disease Rating Scale [UPDRS] III) of the ICARS, in 50 unselected MSA patients (mean age, 67.6 years; mean disease duration, 5.5 years), 50 age-matched and disease duration-matched Parkinson' disease (PD) patients, and 50 control subjects. Fifteen patients (30%) had MSA-C (cerebellar subtype) and 35 (70%) MSA-P (parkinsonism subtype), and 66% had at least one cerebellar sign. The total ICARS score was much higher (fivefold) in MSA compared to PD patients. The ICARS score was twofold higher in MSA-C than in MSA-P patients. MSA-C patients had a higher score than MSA-P mainly on posture and gait disturbances and kinetic functions subscores. All the ICARS items were significantly more severe in MSA than in PD patients, who in turn scored higher than the controls. In MSA, internal consistency was excellent (Cronbach = 0.93). Factor structure analysis revealed four clinically distinct subscores, in accordance with the scale structure, which accounted for 70% of the variance. The ICARS showed less consistency and accuracy in PD patients; however, the ICARS scores significantly correlated with the UPDRS-III scores in both MSA and PD patients. The ICARS appears a useful tool to extract and rate the severity of cerebellar signs in MSA; however, it is clearly contaminated by parkinsonian features.

Precipitation fluctuations during the winter season from 1960 to 1995 over Emilia-Romagna, Italy

¶The variability of the winter mean precipitation observed at 40 rainfall stations in Emilia-Romagna (a region in northern Italy) from 1960 to 1995 is examined. The results are compared with those obtained for the whole of Italy using records from 32 stations. Temporal variability of the time series is investigated by means of Mann-Kendall and Pettitt tests, in order to estimate the presence of trends and “change points”. Before analysis the original precipitation data set have been tested to detect the inhomogeneity points, using the Standard Normal Homogeneity Test (SNHT). Almost all stations situated in Emilia Romagna exhibit a significant decreasing trend in winter precipitation during the 1960–1995 period. The same characteristics are revealed, more significant in the northern and central part of the region, when the stations for all Italy are analysed. A significant downward shift in the winter precipitation is detected through the Pettitt test in Emilia Romagna, around 1980 at some stations, while the rest of the stations reveal the shift point occurrence around 1985. A significant downward shift in the winter precipitation is detected around 1985, when analysing the time series for all Italy. Spatial variability of winter precipitation is studied using the Empirical Orthogonal Function. The first pattern indicates that a common large-scale process could be responsible for the winter precipitation variability. The second EOF pattern shows an opposite sign of climate variability, which highlights the influence of relief on the precipitation regime. The time series associated with the first precipitation pattern (PC1) at both scales emphasises a significant decreasing trend and a downward shift point around 1985. The internal structure analysis of the North Atlantic Oscillation (NAO) index during the 1960–1995 period reveals a significant increasing trend and an upward shift around 1980. Strong correlation is also detected between PC1 (Emilia Romagna and at the scale of all Italy) and the NAO index. Thus, the changes detected in the winter precipitation around 1985 could be due to an intensification of the positive phase of the [NAO], especially after 1980.

The nature of the receptor site for the reversible K + channel blocking by aminopyridines

This work presents a theoretical study aimed at the identification of the receptor site for the blocking of the voltage dependent K + channels by protonated aminopyridines. Thus, the density functional theory (DFT) at the B3LYP/6-311 G (d,p) level is applied, both in vacuum and in solution, to a series of active (protonated) compounds: 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 3,4-diaminopyridine, and 4-aminoquinoleine. Analysis of the X-ray structure of the α-subunit of the channel shows that charged aminopyridines can interact electrostatically with a glutamic acid residue in the outside of the pore, or through a cation–π interaction in the inside. To test both possibilities, model complexes are built using as nucleophiles a carboxylic group and an ethylene molecule, respectively. The three-dimensional electrostatic potential distribution of the protonated aminopyridines shows that an approaching nucleophile will be oriented toward the NH (protonated) bond. Interaction with the carboxylic residue leads to a proton transfer, with the aminopyridinecarboxylic acid linked by a hydrogen bond. The observed breaking of the equivalence of the Laplacian of the charge density, the relative energy variation for the complexes, and the interaction with only one of the carboxylic residues in the fourfold α-subunit of the K + channel are not compatible with the observed in vitro activity variation of aminopyridines. On the other hand, the study on the ethylene complexes shows, in vacuum and solution, a cation–π interaction, clearly characterized by the atoms in molecules (AIM) theory. The variation of relative energy in solution is very small, but approaches the variation of in vitro activity. Our results, the pharmacophoric characteristics of aminopyridines, and the analysis of the three-dimensional internal structure of the K + channel α-subunit suggest two putative receptor sites. One is formed by the four ThrThrVal chains conforming the entrance to the narrow part of the inner K + channel. The other is defined by four Thr residues within the pore.

Particle image velocimetry measurement of in-cylinder flow in internal combustion engines-experiment and flow structure analysis

A cross-correlation digital particle image velocimetry (PIV) system has been developed and applied to study the in-cylinder flow in a single-cylinder engine with a production-type cylinder head. The PIV system set-up and its optimization are described in the first part of the paper. Two-dimensional velocity distributions measured over 100 cycles are analysed to obtain ensemble-averaged mean and fluctuating velocities, the turbulent length scale, vorticity and strain rate distribution in the measurement plane. In particular, a spatial filtering scheme is developed in order to obtain the cycle-resolved velocity measurements. The cycle-resolved analysis shows that the low-frequency velocity fluctuation component (i.e. cyclic variation) is mainly responsible for the spatial variation in velocity and turbulent kinetic energy distributions. The integral length scale calculated from the PIV data is between 6 and 10 mm and the strain rate is estimated to be within 1000 s-1 in most areas of the measurement plane.

Novel deprocessing technique for failure analysis of flip-chip integrated circuit packages

A novel technique for flip-chip package deprocessing that allows for detailed failure analysis of internal flip-chip packaging structures and chip circuitry has been developed. A systematic approach of selective wet etching and plasma etching is utilized. Understanding of package level reliability can be greatly enhanced with the capability to systematically access and examine defects in three-dimensions with powerful analytical tools such as the SEM/EDS. Additionally, the ability to inspect large areas of internal packaging structures, e.g., solder bump array, in three-dimensions makes it faster and more convenient to locate defects, compared to two-dimensional techniques such as progressive cross-sectioning. Case studies involving defects in solder bumps, underfill material, and substrate metallization are presented.

Rheology of Poly(ethylene oxide)/Organoclay Nanocomposites

A series of poly(ethylene oxide) (PEO)/organoclay nanocomposites have been prepared via a solvent casting method. Using three different organoclays modified with the alkylammonium salts, the effect of surfactants on organoclay surfaces in polymer/organoclay nanocomposites was investigated by focusing on two major aspects: internal structure analysis and rheological measurement of the nanocomposites. The d spacings of both the pure PEO and intercalated organoclay were examined via X-ray diffraction analysis, and the microstructure of these nanocomposites was examined by transmission electron microscopy. Rheological properties of these nanocomposites exhibited different behavior with different modifier concentrations and surfactant sizes (chain lengths). To analyze the non-Newtonian flow behavior, we fitted shear viscosity data via the Carreau model, showing that steady shear viscosity and power-law behavior increase with organoclay content. Hysteresis phenomenon was also enhanced with organoclay content, ...

Consumer store choice dynamics: an analysis of the competitive market structure for grocery stores

This study aims at formulating and testing a model of store choice dynamics to measure the effects of consumer characteristics on consumer grocery store choice and switching behavior. A dynamic hazard model is estimated to obtain an understanding of the components influencing consumer purchase timing, store choice, and the competitive dynamics of retail competition. The hazard model is combined with an internal market structure analysis using a generalized factor analytic structure. We estimate a latent structure that is both store and store chain specific. This allows us to study store competition at the store chain level such as competition based on price such as EDLP versus a Hi-Lo pricing strategy and competition specific to a store due to differences in location.

Some analyses of Erdős collaboration graph

Abstract Patrick Ion (Mathematical Reviews) and Jerry Grossman (Oakland University) maintain a collection of data on Paul Erdos, his co-authors and their co-authors. These data can be represented by a graph, also called the Erdos collaboration graph. In this paper, some techniques for analysis of large networks (different approaches to identify ‘interesting’ individuals and groups, analysis of internal structure of the main core using pre-specified blockmodeling and hierarchical clustering) and visualizations of their parts, are presented on the case of Erdos collaboration graph, using the program Pajek .

Homologies in stylophora:A test of the ‘calcichordate theory’

Abstract Stylophora (cornutes and mitrates) are controversial Paleozoic fossils, variously interpreted as ‘bizarre’echinoderms or as ‘calcichordates’ (primitive chordates). The calcichordate theory is based on the identification of left/right asymmetries supposed to be homologous in stylophorans and modern chordates. This theory imposes the homology of the plano-concave surface of the cornute test with the convex surface of the mitrate test. A detailed analysis of numerous internal and external structures exhibited by the appendage and the test demonstrates the homology of the plano-concave surface of the test in all stylophorans. The basic assumption of the calcichordate theory is thus not valid. Comparison of left/right asymmetries in these organisms with those of modem chordates is not grounded. Stylophora do not represent `calcichordates' but actual echinoderms.

Understanding Supermarket Competition Using Choice Maps

In this paper we propose a model which combines the spatial interaction models with the latest developments in internal market structure analysis and allows us to infer supermarket competition from revealed preference data. Using a nested logit formulation we model consumers' store choice decisions to be a two stage process in which consumers choose first the suburb and then the store from which to buy groceries. Hence, our method allows retail managers not only to understand the advantage (or disadvantage) of having their store chain in a particular area but also assess the competition within that area. Comparisons to Factor Analytic Choice Map is made.

218 マイクロ X 線 CT による骨の内部構造解析

218 マイクロ X 線 CT による骨の内部構造解析

Analysis and design of internal web structure of laser stereolithography patterns for investment casting

Shell cracking in investment casting with webbed stereolithography patterns may be problematic during the pattern burnout process. It is due to the maximum thermal stress generated in the ceramic shell exceeding the modulus of rupture of the shell material at a temperature (i.e. the shell rupture temperature) which is lower than both the glass transition temperature of the pattern material and the web link buckling temperature. This paper presents a finite element analysis (FEA)-based numerical simulation of the thermal stresses generated during the pattern burnout process. For efficient numerical simulation, an equivalent force technique is developed for the FEA. The predicted thermal stresses agree fairly well with the measured stresses by strain gauges mounted on the test samples of webbed epoxy patterns. Using the finite element analysis, three internal web structures of stereolithography patterns are compared. The FEA results show that the maximum thermal stress with the hexagonal web structure is 22% less than that with the square web structure and 32% less than that with the triangular web structure. The FEA results are useful to the development of computer-aided engineering tools for the design of the pattern’s internal web structure.

European Y-Chromosomal Lineages in Polynesians: A Contrast to the Population Structure Revealed by mtDNA

We have used Y-chromosomal polymorphisms to trace paternal lineages in Polynesians by use of samples previously typed for mtDNA variants. A genealogical approach utilizing hierarchical analysis of eight rare-event biallelic polymorphisms, seven microsatellite loci, and internal structural analysis of the hypervariable minisatellite, MSY1, has been used to define three major paternal-lineage clusters in Polynesians. Two of these clusters, both defined by novel MSY1 modular structures and representing 55% of the Polynesians studied, are also found in coastal Papua New Guinea. Reduced Polynesian diversity, relative to that in Melanesians, is illustrated by the presence of several examples of identical MSY1 codes and microsatellite haplotypes within these lineage clusters in Polynesians. The complete lack of Y chromosomes having the M4 base substitution in Polynesians, despite their prevalence (64%) in Melanesians, may also be a result of the multiple bottleneck events during the colonization of this region of the world. The origin of the M4 mutation has been dated by use of two independent methods based on microsatellite-haplotype and minisatellite-code diversity. Because of the wide confidence limits on the mutation rates of these loci, the M4 mutation cannot be conclusively dated relative to the colonization of Polynesia, 3,000 years ago. The other major lineage cluster found in Polynesians, defined by a base substitution at the 92R7 locus, represents 27% of the Polynesians studied and, most probably, originates in Europe. This is the first Y-chromosomal evidence of major European admixture with indigenous Polynesian populations and contrasts sharply with the picture given by mtDNA evidence.

Internal structure of a domain wall in ultrathin magnetic film

Micromagnetic analysis of a domain wall internal structure in ultrathin magnetic film is carried out. The case when the film thickness is much smaller than the exchange length (the effective width of a Bloch line) is considered. It is shown that in this limiting case the angle of the domain wall twisting is very small and the domain wall has the quasi-Bloch structure.

Probabilistic Study for Image Analysis of Internal Structure in 2 -Dimensional Short Fiber Reinforced Composites

Probabilistic Study for Image Analysis of Internal Structure in 2 -Dimensional Short Fiber Reinforced Composites

Structure of a High Efficiency Glass Fiber Filter Medium

ABSTRACT The analysis of the real internal structure of a high efficiency glass fiber filter medium was carried out to provide detailed structure data, e.g., for more realistic calculations of the filter performance. The procedure of the structure analysis is described in detail and the most important results are presented and discussed. The fiber diameter distribution was found to be constant throughout the HEPA medium studied. The fibers tended to be oriented perpendicular to the direction of air flow, but there was no preferred direction of orientation within the plane of the filter medium. The interfiber distance distributions in parallel as well as in perpendicular orientation to air flow direction were found to be of the expected exponential shape for distances > 1 μm. On the other hand, the frequencies of the distances < 1 μm increase and the exponential shape of the curves is no longer observed.

A Dynamic Analysis of Market Structure Based on Panel Data

Internal market structure analysis infers brand positions in an attribute space from preference and choice data, given a market in which consumers have heterogeneous tastes for attributes. Previous market structure models have adopted a static framework (e.g., Elrod 1988, Chintagunta 1994, Elrod and Keane 1995). Furthermore, they assumed that consumer perceptions of brand attributes do not vary across consumers. Yet, these approaches may render inaccurate representations of market structure if there is state dependence in consumer choice behavior. This paper attempts to incorporate consumer choice dynamics into market structure models by specifying the source of choice dynamics explicitly. In particular, the process by which past purchases affect current choices is modeled in a framework which captures both consumer habit persistence and variety seeking behavior. More specifically, consumer preferences for brand attributes are modeled to depend on the attributes of brands bought on the previous purchase occasion. Furthermore, the modeling approach adopted incorporates heterogeneity in both consumer preferences and perceptions of brand attributes. The audience of this paper includes practitioners and academics interested in understanding consumer choice processes and inferring market structure from consumer choice data. The proposed models are estimated on Nielsen scanner panel data for margarine, peanut butter, yogurt, and liquid detergent using simulated maximum likelihood techniques. The empirical results suggest that accounting for choice dynamics improves both in-sample and out-of-sample fit. The results indicate that the average consumer is habit persistent in all the product categories studied. This result is consistent with the findings of Kannan and Sanchez (1994), who conducted an aggregate analysis of consumer variety seeking behavior across product categories. However, the results obtained in this paper suggest that consumers are heterogeneous with respect to the processes by which past purchases affect current purchases. These results provide strong evidence for habit persistence and variety seeking in brand attributes to be the behavioral source of consumer choice dynamics in food categories. Thus, consumer tastes (utility weights) seem to be affected by the attributes of the brands consumed in the past. Given the empirical result that a large proportion of consumers are habit persistent, this suggests that tastes are reinforced by the brand attributes consumed in the past. The empirical results also show that not accounting for state dependence in market structure models for panel data may produce misleading results, that is, depending on consumer behavior patterns, models that do not account for state dependence may distort the true nature of competition among brands. More specifically, the results confirm the expectation that if there is habit persistence, that is, if consumer tastes are reinforced by attributes of brands consumed in the past, models that do not capture this choice dynamics will overestimate the distance between (similar) brands. Furthermore, the policy experiments conducted suggest that (1) static models overestimate the short-run impact of a price cut on the sales of the brand on promotion, (2) price cuts hurt the sales of the more similar brands more, and (3) free samples affect relatively less similar brands the most. Finally, this paper studies variety seeking and habit persistence across brands over purchase occasions. However, variety seeking behavior may also involve the purchase of a portfolio of brands or items at a purchase occasion. Consumers may buy multiple items knowing that prior to the next trip they may want to consume different items (Simanson 1990, Walsh 1995). This type of behavior can be modeled within the context of dynamic expected utility maximization with forward-looking consumers. The development and estimation of market structure models that include forward-looking consumers who maximize expected-utility over a planning horizon, incorporating their future tastes and needs, and shopping for an inventory of brands, remain an important future research issue.

Theoretical considerations on medical concept representation.

Concepts are seen as building elements of more compositional information objects in medicine. Consequently, representation of medical concepts plays a critical role in any information system. The authors present some of the key problems which need solution, such as definition of medical domain, analysis of internal structure, different subsets of medical concepts, and the problem of the 'elementary' concepts. As a result of these considerations we can conclude that the domain of medical concepts can hardly be delimited and consists of different subsets. These subsets need different representation methods according to their different nature. Some of these subsets have a hierarchic structure. In those one can find sometimes multiple hierarchies. We suggest avoiding multiple hierarchies in concept systems by the introduction of new dimensions.

Analysis of internal structures of composite materials by second-order property of mosaic patterns

Properties of composite materials depend on their internal structures which in most cases are highly random. Therefore, high-order information is often required for quantitative characterization of morphological features in spatial distributions of the constituent phases. The present study develops a general expression for a second-order moment, that is, autocorrelation function R x υ, of multiphase heterogeneous composites. The obtained R x υ depends on three types of parameters: volume fractions of the constituent phases, values of the phase function, and π (the probability that two points with distance υ are in the same basic cell). π depends on the constitution of the basic cell, and thus the specific characteristics of the internal structure of the material. To determine completely the autocorrelation function, probability π is derived based on a morphological model called mosaic patterns. Derivation of π for two types of mosaic patterns indicates that π [and thus R x ( υ)] has different formulations for different internal structures, although all of them depend on the same set of parameters: coarseness of microstructures, λ, volume fraction of constituent phases, Φ, and values of the chosen phase function. For a two-phase composite, with increasing Φ 1 (volume fraction of phase 1), the value of R x υ increases; while, with increasing λ, the structure of the composite becomes more and more fine grained, and thus the correlation between two points with a fixed distance υ becomes weaker. As an example of applications of the present result, the autocorrelation function is applied to predict the fluctuation of local volume fractions of two-phase composite materials.