bluuebunny/crossref_metadata_2025 huggingface dataset:
Powder X-Ray Diffraction Data for the Superconducting Phase TlCaBa2Cu2O7−δ
Authors: Aselage Terry L. , Eatough Michael O.
Published: January 2013

High temperature superconducting phases in the Tl-Ca-Ba-Cu-O system are ideally represented by the formula TlmCan−1Ba2CunO2(n+1)+m, with m either 1 or 2 and n = 1 to at least 3 (Parkin et at., 1988). Each of these phases contains one or more of the nearly planar CuO2sheets common to the cuprate superconductors. A single Ca atom separates adjacent CuO2sheets (n > 1). Single or double rock salt-like Tl-O layers are separated from the Can−1CunO2nregions by single Ba-O layers. Each of the Ca-containing members of this family crystallizes in a tetgragonal unit cell, with space group 14/mmm for the m = 2 series and P4/mmm for the m = 1 series.

Despite the general interest in this family of superconductors, little has been reported about the m = 1, n = 2 member, TlCaBa2Cu2O7−δ, hereafter called 1122. This lack of work is due at least in part to the difficulty in synthesizing the pure compound (Michel et at., 1991). Additionally, technological interest has focused on members of the family with higher superconducting transition temperatures, particularly Tl2Ca2Ba2Cu3Oywith Tcup to 125 K. The critical temperature of 1122 has been reported from as low as 50 K (Hervieu et al., 1988) to as high as 103 K (Morosin et al., 1988), and at several values in between (Ganguli et al., 1988; Liang et al., 1988). Most of the samples had other superconducting phases in addition to 1122. Because of the nearly identical a axis lengths of the unit cells of the Tl-family of superconductors, syntactic intergrowths may be present in such multiphase samples.
A Crystallographic Re-Examination of the (Fe,W)6C Phase Field in the Fe-W-C System
Authors: Azubike D.C. , Chrysanthou A. , Igiehon U.O.
Published: January 2013

A more accurate X-ray diffraction pattern for the high speed steel carbide Fe3W3C is presented. This pattern includes the low angle reflections omitted from previous studies. A wider homogeneity range for the M6C carbide phase at 1200° C is suggested.
X-Ray Powder Diffraction Data for Tetragonal Zirconia Solid Solutions in System ZrO2-YTaO4
Authors: Kim Dae-Joon , Hubbard Camden R.
Published: January 2013

Tetragonal zirconia (t- ZrCO2) can be stabilized with 15 to 22 mol% YTaO4. X-ray powder diffraction data for the end members of the solid solution series Zr0.76Y0.12Ta0.12O2 and Zr0.66Y0.17Ta0.17O2 are reported along with lattice parameters across the single phase region. These tetragonal zirconias are characterized by large tetragonalities (c/ √ 2a > 1.0203) and nontransformability to the monoclinic structure.
Barium Rare Earth Titanates: X-Ray Characterization of BaR2Ti3O10 and BaR2Ti4O12: R = Lanthanide
Authors: Jing X. , Zheng C. , West A.R.
Published: January 2013

The compounds, BaR2Ti3O10: R = La, Pr, Nd and Sm; BaR2Ti4O12: R = La, Pr, Sm, Gd, Eu have been prepared by solid state reaction and characterized by X-ray powder diffraction. Unit cell data are summarised; lattice parameters and unit cell volumes increase approximately linearly with lanthanide ion size.
A Suggestion on the Standard X-Ray Powder Diffraction Pattern of Barium Ferrite
Authors: Shin H.S. , Kwon S.-J.
Published: January 2013

We have examined the barium ferrite powder X-ray diffraction patterns in the PDF using experimental and calculated diffractograms. An improved calculated diffractogram is proposed. The result indicates that the primary peak of barium ferrite is not (107) but is (114).
An Application of Calculated X-Ray Diffraction Patterns in the Analysis of Reference Powder Data: Trivalent Metal Sulfates
Authors: Pollack Sidney S. , McCarthy Gregory J. , Holzer Jean M.
Published: January 2013

Powder diffraction patterns have been calculated for nine isostructural rhombohedral M2(SO4)3 (M = Sc, Ti, V, Cr, Fe, Ga, Y, Rh, In) phases, and for four isostructural monoclinic M2(SO4)3 (M = V, Fe, In, Tl) phases. The pattern for monoclinic Fe2(SO4)3 is the first reported for this phase. Because structure data are available only for the two Fe2(SO4)3 polymorphs, the powder patterns of the other trivalent metal sulfates were approximated using the structure data of the isostructural Fe phases with the scattering factors and previously determined cell parameters of the various metal sulfates. These calculated patterns are termed an approximation by isostruduralism.

The calculated patterns were used to evaluate reference powder data for these phases in the Powder Diffraction File (PDF). All but two of the PDF patterns were found to differ substantially from the calculated patterns in the stronger peaks used for identification, and to be missing weak peaks that may be confused for impurities during phase identification.
Cerium Oxygen Apatite (Ce4.67[SiO4]3O) X-Ray Diffraction Pattern Revisited
Authors: Tas A. Cuneyt , Akinc Mufit
Published: January 2013

A new X-ray diffraction pattern for the compound cerium oxygen apatite, Ce4.67[SiO4]3O is suggested. The compound was prepared by the solid state reaction of the oxides, CeO2 and SiO2 and has a hexagonal crystal structure with the lattice constants a = 9.6578 Å and c = 7.1187 Å. The sample of the most recent PDF pattern 31-0336* (Visser, 1978) for this compound is believed to be contaminated with significant quantities of N owing to the fact that it was prepared by mixing Ce2O3 and Si3N4 and its very close resemblance to the pattern displayed in the PDF 33-0333 given for the cerium “nitrogen” apatite, Ce5[SiO4]3N.
X-Ray Powder Diffraction Pattern for Reaction-HIPed A118Ti2Mg3
Authors: Gayle Frank W. , Biancaniello Francis S. , Schaefer Robert J. , Jiggets Rodney D.
Published: January 2013

The cubic Al18Ti2Mg3 phase (184 atoms/unit cell, Z = 8, space group Fdm) has been fabricated by reaction hot isostatic pressing. Quantitative energy dispersive X-ray analysis showed the phase to have nearly ideal stoichiometry. Interplanar spacings and diffraction peak intensities have been determined by X-ray diffraction. The experimental data show good agreement with the pattern calculated using atomic site positional parameters for A118Cr2Mg3, confirming that A118Cr2Mg3 is the prototype for A118Ti2Mg3.
X-Ray and Optical Data for a Vanadium-rich Dravite from Silver Knob, Mariposa County, California, U.S.A.
Authors: Foit Franklin F.
Published: January 2013

X-ray powder diffraction and optical data are presented for a vanadium-rich dravite from Silver Knob, Mariposa County, California, U.S.A. The limited compositional variability observed for vanadium-rich dravite is due to the presence of a Tschermaks substitution whereby the substitution of Al for Si in the tetrahedral ring is charge balanced by trivalent for divalent cation substitution in the octahedral sites in the structure. Vanadium-rich dravite is uniaxial negative with ε = 1.646(2) and ω = 1.676(2). Refined unit cell dimensions are a = 15.9599(10) and c = 7.1889(2); F30 = 111(0.009; 30); M20 = 80; and Dx = 3.07. An indexed X-ray powder diffraction pattern is also presented.
Peaks in the background from single-crystal substrates measured with parallel beam optics
Authors: van der Sluis P.
Published: January 2013

An X-ray detector chain consisting of a Xe-filled proportional detector followed by a pulse height analyzer tuned to 8.1 keV may register energies between 5 and 45 keV, although with a low efficiency at the edges. For diffraction experiments on single-crystalline substrates, these diffracted intensities can be significant. In the high-energy range, regions of even higher intensity are found due to the so-called escape process. In the diffraction angle scan of an (001) oriented Si single-crystal measured with a low (fixed) incidence angle, we have identified 21 peaks, originating from three different diffraction processes: diffraction from white radiation, diffraction observed via an escape process, and crystal truncation rod scattering. These peaks interfere with diffraction studies if such a single crystal is used as a substrate for polycrystalline samples. A great reduction in the substrate background and removal of most of the substrate diffraction peaks is achieved with a graphite monochromator or with a graphite monochromator together with a β-filter.
X-ray diffraction data of Ti2O2(C2O4)(OH)2·H2O
Authors: Choi Hee-Lack , Enomoto Naoya , Ishizawa Nobuo , Nakagawa Zenbe-e
Published: January 2013

X-ray powder diffraction data for Ti2O2(C2O4)(OH)2·H2O were obtained. The crystal system was determined to be orthorhombic with space group C2221. The unit cell parameters were refined to a = 1.0503(2) nm, b = 1.5509(3) nm, and c = 0.9700(1) nm.
X-ray for the superconducting phase TIBa2Ca2Cu3O9−δ diffraction data
Authors: Eatough Michael O. , Aselage Terry L.
Published: January 2013

Accurate powder diffraction data for the superconducting phase TlBa2Ca2Cu3O9−δ have been obtained. This phase crystallizes in a tetragonal unit cell, with space group P4/mmm. Cell refinement of our material resulted in a tetragonal unit cell with a=3.8453(8)Å and c = 15.909(4)Å. These diffraction data improve on data currently present in the powder diffraction file. Our experimental data also agree with calculated diffraction patterns obtained from published atom positions.
Pitfalls in the powder diffraction analysis of zeolites ZSM-5 and ZSM-8
Authors: Weidenthaler Claudia , Fischer Reinhard X. , Shannon Robert D.
Published: January 2013

Crystal structure analyses by the Rietveld method have shown that the framework structures of zeolites ZSM-5 and ZSM-8 are essentially identical. Therefore, it is difficult to distinguish the two phases especially when the template-free H forms are studied. In addition, some inconsistencies in publications on the two zeolites aggravate the correct interpretation of the powder diagrams. A powder pattern published for ZSM-8 which indicates significant differences between the lattice constants of ZSM-8 and ZSM-5 is shown to be incorrectly indexed. Correct reindexing gives lattice constants for ZSM-8 matching average ZSM-5 values. Peak splitting of a ZSM-8 reflection at 2θ≈23° (CuKα) has been used frequently to distinguish ZSM-8 from ZSM-5. However, it is also a common feature of ZSM-5 diagrams when the difference betweenaandblattice constants is big enough to separatehklandkhlreflections within the instrumental resolution. Our data on two ZSM-8 samples indicate that cell dimensions of ZSM-8 do not deviate from average ZSM-5 values. It is suspected that effects in the decomposition of crystals upon calcination, and/or morphology and shape of twin individuals, and/or stacking faults account for different sorption properties of the two zeolites rather than differences in their average crystal structures.
The effect of peak choice on the quantitative phase analysis of the Egyptian kaolins using the standardless method
Authors: El-Sayed Karimat , Heiba Z. K. , El-Rahman A. M. Abd
Published: January 2013

The “standardless” quantitative phase analysis method proposed by Rius, Plana, and Planques [J. Appl. Cryst. 20, 457 (1987)] was evaluated by applying it to two series of artificial samples. The method was then applied to determine quantitatively the phases present in six different natural kaolin samples from Egypt. Two kaolinite peaks were selected for this analysis: One of them is known to be affected by stacking disorder, the other one is the 001 basal reflection, which is not significantly affected by stacking disorder. The method was also applied to samples of different mesh sizes. The results obtained when using the basal reflection showed that Egyptian kaolin is mainly kaolinite (82%–95%) together with anatase (2%–9%), rutile (1%–6%), and quartz (0.5%–7%). These analyses agreed very well with those obtained by chemical analysis. On the other hand, the analyses of the phases obtained from the peak which is strongly affected by stacking disorder were totally different. It was found also that by decreasing the particle sizes of kaolin samples the phase abundance of kaolinite increases, whereas those of quartz and anatase decrease. The results showed also that the standardless method is only applicable to peaks that are not strongly affected by structural disorder.
High-temperaturein situRietveld study of Fe,Mg cation partitioning in olivine
Authors: Artioli G. , Bellotto M. , Palosz B.
Published: January 2013

A natural olivine sample from a mantle peridotite xenolith has been studied byin situhigh-temperature powder diffraction. The structure has been successfully refined from powder data at three temperatures (25, 600, and 800 °C) using the Rietveld method. The study shows that the full-profile technique is well suited for the structure analysis of high-temperature powder diffraction data. The results indicate that, in this temperature range, there is no significant ordering of the Fe,Mg cations in the two crystallographically independent octahedral sites. This has implications for the thermodynamic modeling of olivine at upper mantle conditions. The present experiments allowed measurement of the lattice thermal expansion of olivine in the temperature range 25–800 °C, and assessment of the temperature dependence of the isotropic atomic displacement parameters.
Epiphytic diatom communities of Terra Nova Bay, Ross Sea, Antarctica: structural analysis and relations to algal host
Authors: Majewska Roksana , Gambi Maria Cristina , Totti Cecilia Maria , De Stefano Mario
Published: January 2013

Epiphytic diatoms are important constituents of the Southern Ocean coastal water ecosystem, being a key element in many of the Antarctic trophic chains. However, only limited information exists relating to these microalgal communities. Here we describe our findings of a study on epiphytic diatoms from Terra Nova Bay (Ross Sea, Antarctica) based on material collected during the summer campaigns spanning from 1990–2004. Observations of diatoms associated with three rhodophyte species (Iridaea cordata(Turner) Bory,Phyllophora antarcticaGepp & Gepp, andPlocamium cartilagineum(L.) Dixon) were carried out with the use of a scanning electron microscope. A total of 73 diatom taxa (32 genera) were distinguished, of which 20 taxa exceeded 3% of total abundance.Cocconeis fasciolata(Ehrenberg) Brown,Navicula perminutaGrunow, andFragilariopsis nana(Steemann Nielsen) Paasche appeared in every sample. The analysis of similarities (ANOSIM) test as well as non-metric multidimensional scaling analysis indicated the nature of host organism as a major factor influencing associated diatom community structure, whereas depth, site, and time of sampling seemed to be less important. The epizooic communities associated with sessile fauna epiphytic on macroalgae differed significantly from those associated with macroalgal surface. A pronounced difference between the communities epiphytic on various host macroalgae species was also observed, although most of the dissimilarities occurred between diatom taxa of the same growth form.
Personal Identity and Brain Transplants
Authors: Snowdon P. F.
Published: January 2013

My topic is personal identity, or rather,ouridentity. There is general, but not, of course, unanimous, agreement that it is wrong to give an account of what is involved in, and essential to, our persistence over time which requires the existence of immaterial entities, but, it seems to me, there is no consensus about how, within, what might be called this naturalistic framework, we should best procede. This lack of consensus, no doubt, reflects the difficulty, which must strike anyone who has considered the issue, of achieving, just in one's own thinking, a reflective equilibrium. The theory of personal identity, I feel, provides a curious contrast. On the one side, it seems highly important to know what sort of thing we are, but, on the other, it is hard to find any answer which has a ‘solid’ feel.
The Petticoat Inspectors: Women Boarding Inspectors and the Gendered Exercise of Federal Authority
Authors: Pliley Jessica
Published: January 2013

In the early twentieth century, anti-white-slavery activists sought to construct a new position for women inspectors in the Immigration Bureau. These activists asserted that immigrant girls traveling without a family patriarch deserved the U.S. government's paternal protection, yet they argued that women would be best suited to provide this protection because of women's purported maternal abilities to perceive feminine distress. By wielding paternal government authority—marked by a badge, the ability to detain, and presumably the power to punish—these women could most effectively protect the nation's moral boundaries from immoral prostitutes while also protecting innocent immigrant girls from the dangers posed by solitary travel. In 1903 the Immigration Bureau launched an experiment of placing women among the boarding teams at the port of New York. The experiment, however, was short-lived, as opponents of the placement of women in such visible positions campaigned against them. This episode reminds us that the ability to represent and exercise federal authority in the early twentieth century was profoundly gendered; and women's increased participation in government positions during the Progressive Era was deeply contested.
Heresy Is the Only True Religion: Richard Lynch Garner (1848–1920), A Southern Freethinker in Africa and America
Authors: Rich Jeremy
Published: January 2013

Atheists are not the first group that comes to mind when one commonly thinks of late nineteenth-century southern Appalachia. Richard Lynch Garner (1848–1920), a self-taught scientist from southwestern Virginia who moved to southern Gabon in 1892, sought to bind together conventional southern middle-class views on race and manhood with religious skepticism. Studies of unbelief in the United States have almost entirely ignored the South as well as the ways that freethinkers engaged with race, thereby leaving out men like Garner. Though Garner drew on northern and midwestern freethinkers like Robert Ingersoll for critiques of Christianity, he also saw himself as a defender of paternal southern views of race from northerners and from Christian missionaries. Still, he distanced himself from other southern agnostics, especially the race-baiting William Cowper Brann, by presenting himself as a fatherly protector of Africans and African Americans. Garner used his observations on Gabonese societies to critique colonialism and missionary work as denials of biological differences between the races. Interestingly, Garner contended that Gabonese spirituality was materialist and lacked a notion of divinity. Ultimately, Garner downplayed his freethinking and his anti-colonialism in his published work—probably to ensure his ability to continue his research in colonial Africa and perhaps to better market himself in the United States.
Coral and macroalgal exudates vary in neutral sugar composition and differentially enrich reef bacterioplankton lineages
Authors: Nelson Craig E , Goldberg Stuart J , Wegley Kelly Linda , Haas Andreas F , Smith Jennifer E , Rohwer Forest , Carlson Craig A
Published: January 2013

Increasing algal cover on tropical reefs worldwide may be maintained through feedbacks whereby algae outcompete coral by altering microbial activity. We hypothesized that algae and coral release compositionally distinct exudates that differentially alter bacterioplankton growth and community structure. We collected exudates from the dominant hermatypic coral holobiont Porites spp. and three dominant macroalgae (one each Ochrophyta, Rhodophyta and Chlorophyta) from reefs of Mo’orea, French Polynesia. We characterized exudates by measuring dissolved organic carbon (DOC) and fractional dissolved combined neutral sugars (DCNSs) and subsequently tracked bacterioplankton responses to each exudate over 48 h, assessing cellular growth, DOC/DCNS utilization and changes in taxonomic composition (via 16S rRNA amplicon pyrosequencing). Fleshy macroalgal exudates were enriched in the DCNS components fucose (Ochrophyta) and galactose (Rhodophyta); coral and calcareous algal exudates were enriched in total DCNS but in the same component proportions as ambient seawater. Rates of bacterioplankton growth and DOC utilization were significantly higher in algal exudate treatments than in coral exudate and control incubations with each community selectively removing different DCNS components. Coral exudates engendered the smallest shift in overall bacterioplankton community structure, maintained high diversity and enriched taxa from Alphaproteobacteria lineages containing cultured representatives with relatively few virulence factors (VFs) (Hyphomonadaceae and Erythrobacteraceae). In contrast, macroalgal exudates selected for less diverse communities heavily enriched in copiotrophic Gammaproteobacteria lineages containing cultured pathogens with increased VFs (Vibrionaceae and Pseudoalteromonadaceae). Our results demonstrate that algal exudates are enriched in DCNS components, foster rapid growth of bacterioplankton and select for bacterial populations with more potential VFs than coral exudates.
Ecology of marine Bacteroidetes: a comparative genomics approach
Authors: Fernández-Gómez Beatriz , Richter Michael , Schüler Margarete , Pinhassi Jarone , Acinas Silvia G , González José M , Pedrós-Alió Carlos
Published: January 2013

Bacteroidetes are commonly assumed to be specialized in degrading high molecular weight (HMW) compounds and to have a preference for growth attached to particles, surfaces or algal cells. The first sequenced genomes of marine Bacteroidetes seemed to confirm this assumption. Many more genomes have been sequenced recently. Here, a comparative analysis of marine Bacteroidetes genomes revealed a life strategy different from those of other important phyla of marine bacterioplankton such as Cyanobacteria and Proteobacteria. Bacteroidetes have many adaptations to grow attached to particles, have the capacity to degrade polymers, including a large number of peptidases, glycoside hydrolases (GHs), glycosyl transferases, adhesion proteins, as well as the genes for gliding motility. Several of the polymer degradation genes are located in close association with genes for TonB-dependent receptors and transducers, suggesting an integrated regulation of adhesion and degradation of polymers. This confirmed the role of this abundant group of marine bacteria as degraders of particulate matter. Marine Bacteroidetes had a significantly larger number of proteases than GHs, while non-marine Bacteroidetes had equal numbers of both. Proteorhodopsin containing Bacteroidetes shared two characteristics: small genome size and a higher number of genes involved in CO2 fixation per Mb. The latter may be important in order to survive when floating freely in the illuminated, but nutrient-poor, ocean surface.
Microdiversity of extracellular enzyme genes among sequenced prokaryotic genomes
Authors: Zimmerman Amy E , Martiny Adam C , Allison Steven D
Published: January 2013

Understanding the relationship between prokaryotic traits and phylogeny is important for predicting and modeling ecological processes. Microbial extracellular enzymes have a pivotal role in nutrient cycling and the decomposition of organic matter, yet little is known about the phylogenetic distribution of genes encoding these enzymes. In this study, we analyzed 3058 annotated prokaryotic genomes to determine which taxa have the genetic potential to produce alkaline phosphatase, chitinase and β-N-acetyl-glucosaminidase enzymes. We then evaluated the relationship between the genetic potential for enzyme production and 16S rRNA phylogeny using the consenTRAIT algorithm, which calculated the phylogenetic depth and corresponding 16S rRNA sequence identity of clades of potential enzyme producers. Nearly half (49.2%) of the genomes analyzed were found to be capable of extracellular enzyme production, and these were non-randomly distributed across most prokaryotic phyla. On average, clades of potential enzyme-producing organisms had a maximum phylogenetic depth of 0.008004–0.009780, though individual clades varied broadly in both size and depth. These values correspond to a minimum 16S rRNA sequence identity of 98.04–98.40%. The distribution pattern we found is an indication of microdiversity, the occurrence of ecologically or physiologically distinct populations within phylogenetically related groups. Additionally, we found positive correlations among the genes encoding different extracellular enzymes. Our results suggest that the capacity to produce extracellular enzymes varies at relatively fine-scale phylogenetic resolution. This variation is consistent with other traits that require a small number of genes and provides insight into the relationship between taxonomy and traits that may be useful for predicting ecological function.
Residue mutations and their impact on protein structure and function: detecting beneficial and pathogenic changes
Authors: Studer Romain A. , Dessailly Benoit H. , Orengo Christine A.
Published: January 2013

The present review focuses on the evolution of proteins and the impact of amino acid mutations on function from a structural perspective. Proteins evolve under the law of natural selection and undergo alternating periods of conservative evolution and of relatively rapid change. The likelihood of mutations being fixed in the genome depends on various factors, such as the fitness of the phenotype or the position of the residues in the three-dimensional structure. For example, co-evolution of residues located close together in three-dimensional space can occur to preserve global stability. Whereas point mutations can fine-tune the protein function, residue insertions and deletions (‘decorations’ at the structural level) can sometimes modify functional sites and protein interactions more dramatically. We discuss recent developments and tools to identify such episodic mutations, and examine their applications in medical research. Such tools have been tested on simulated data and applied to real data such as viruses or animal sequences. Traditionally, there has been little if any cross-talk between the fields of protein biophysics, protein structure–function and molecular evolution. However, the last several years have seen some exciting developments in combining these approaches to obtain an in-depth understanding of how proteins evolve. For example, a better understanding of how structural constraints affect protein evolution will greatly help us to optimize our models of sequence evolution. The present review explores this new synthesis of perspectives.
Organizing the genome with H2A histone variants
Authors: Millar Catherine B.
Published: January 2013

Chromatin acts as an organizer and indexer of genomic DNA and is a highly dynamic and regulated structure with properties directly related to its constituent parts. Histone variants are abundant components of chromatin that replace canonical histones in a subset of nucleosomes, thereby altering nucleosomal characteristics. The present review focuses on the H2A variant histones, summarizing current knowledge of how H2A variants can introduce chemical and functional heterogeneity into chromatin, the positions that nucleosomes containing H2A variants occupy in eukaryotic genomes, and the regulation of these localization patterns.
Vocabulary Use Across Genres: Implications for Students With Complex Communication Needs
Authors: Clendon Sally A. , Sturm Janet M. , Cali Kathleen S.
Published: January 2013

Purpose

This study examined the vocabulary words and multiword sequences used by 124 typically developing kindergarten and 1st-grade students when they wrote about self-selected topics. The study extends previous research by examining the vocabulary used in different genres.

Method

A total of 457 writing samples were analyzed. The samples were classified according to 9 genres and were analyzed using the Child Language Analysis (MacWhinney, 2006) software program.

Results

The authors found that 140 words represented 70% of the vocabulary produced. The most common genre types were narrative recounts and opinions. The patterns of frequency for words and multiword sequences varied across genres. The degree of variation was greater for particular vocabulary words. For instance, the word
going
was used predominantly in 1 genre. In contrast, the word
mom
was used in every genre except 3. The structure words tended to be used with high frequency across genres.

Conclusion

The word lists generated can be used to inform vocabulary selection, organization, and instruction for students with complex communication needs who are beginning writers.

Supplemental Material

https://doi.org/10.23641/asha.6170273
Morphological Analysis in Context Versus Isolation: Use of a Dynamic Assessment Task With School-Age Children
Authors: Ram Gayatri , Marinellie Sally A. , Benigno Joann , McCarthy John
Published: January 2013

Purpose

The current study investigated the ability of typically developing children in Grades 3 and 5 to use morphological analysis to determine the meanings of derived words with and without context clues. Also of interest was the relation between children’s reading practices and their performance in determining the meanings of derived words.

Method

Children provided definitions for 20 low-frequency derived words that were presented to them in isolation and in context. Responses were scored on a scale of 0 to 5 based on the children’s performance on the Dynamic Assessment of Morphological Analysis—Modified (DATMA–M), which was created by the authors.

Results

Results indicated a large variability in the children’s performance on the DATMA–M. Children in Grade 5 achieved significantly higher scores as compared to children in Grade 3. Overall, children performed better in the context condition than the isolation condition. Significant correlations were found for reading frequency and DATMA–M scores. There was no significant difference in performance between the isolation and context conditions after controlling for reading frequency.

Conclusion

The findings of this study emphasize the need for continued research to enable speech-language pathologists to use assessments such as the DATMA–M to obtain insights into the morphological analytical skills of school-age children.
Readability of Questionnaires Assessing Listening Difficulties Associated With (Central) Auditory Processing Disorders
Authors: Atcherson Samuel R. , Richburg Cynthia M. , Zraick Richard I. , George Cassandra M.
Published: January 2013

Purpose

Eight English-language, student- or parent proxy-administered questionnaires for (central) auditory processing disorders, or (C)APD, were analyzed for readability. For student questionnaires, readability levels were checked against the approximate reading grade levels by intended administration age per the questionnaires' developers. For proxy questionnaires, results were compared to the reading grade level for the average U.S. adult and the minimum 5th- to 6th-grade reading level for health materials as recommended by adult health literacy experts.

Method

This was a descriptive study that was based on the results of a commercially available readability calculations software package. Text-based files of the 8 questionnaires were analyzed using 3 readability formulas: FORCAST (Caylor & Sticht, 1973), Flesch Reading Ease (FRE; Flesch, 1948), and Gunning’s Fog index (FOG; Gunning, 1952).

Results

The FORCAST formula, the most appropriate for nonnarrative-type materials, indicated that all 8 questionnaires were written at reading levels between the 8th and 10th grades. The FRE and FOG formulas, designed for narrative-type materials, were generally in good agreement with one another but varied widely between the upper 4th- and 12th-grade levels.

Conclusion

In an effort to decrease respondent burden, developers should consider readability as another testable psychometric construct. Clinicians should take into account the functional health literacy skills of adult proxy respondents when giving self-administered questionnaires.
Differentiating Children With and Without Language Impairment Based on Grammaticality
Authors: Eisenberg Sarita L. , Guo Ling-Yu
Published: January 2013

Purpose

This study compared the diagnostic accuracy of a general grammaticality measure (i.e., percentage grammatical utterance; PGU) to 2 less comprehensive measures of grammaticality—a measure that excluded utterances without a subject and/or main verb (i.e., percentage sentence point; PSP) and a measure that looked only at verb tense errors (i.e., percentage verb tense usage; PVT)—in differentiating children with and without language impairment.

Method

Two groups of 3-year-olds, 17 with language impairment and 17 with typical language, participated in a picture description task. PGU, PSP, and PVT were computed. Receiver operating characteristic curve analyses were conducted to determine the best cutoff value for each measure.

Results

All 3 measures demonstrated a sensitivity of 100%. PGU showed a specificity of 88%, and both PSP and PVT showed a specificity of 82%. In addition, PGU showed a larger positive likelihood ratio than the other 2 measures.

Conclusion

PGU, PSP, and PVT were all sensitive to language impairment. However, PGU was less likely than PSP and PVT to misclassify children with typical language. The resultant diagnostic accuracy makes PGU an appropriate measure to use to screen for language impairment.
Stoichiometry dependence of resistance drift phenomena in amorphous GeSnTe phase-change alloys
Authors: Luckas J. , Piarristeguy A. , Bruns G. , Jost P. , Grothe S. , Schmidt R. M. , Longeaud C. , Wuttig M.
Published: January 2013

In phase-change materials, the amorphous state resistivity increases with time following a power law ρ ∝ (t/t0)αRD. This drift in resistivity seriously hampers the potential of multilevel-storage to achieve an increased capacity in phase-change memories. This paper presents the stoichiometric dependence of drift phenomena in amorphous GeSnTe systems (a-GeSnTe) and other known phase-change alloys with the objective to identify low drift materials. The substitution of Ge by Sn results in a systematic decrease of the drift parameter from a-GeTe (αRD = 0.129) to a-Ge2Sn2Te4 (αRD = 0.053). Furthermore, with increasing Sn content a decrease in crystallization temperature, trap state density, optical band gap, and activation energy for electronic conduction is observed. In a-GeSnTe, a-GeSbTe, and a-AgInSbTe alloys as well, the drift parameter αRD correlates to the activation energy for electronic conduction. This study indicates that low drift materials are characterized by low activation energies of electronic conduction. The correlation found between drift and activation energy of electronic conduction manifests a useful criterion for material optimization.
Asymmetric criticality of the osmotic compressibility in binary mixtures
Authors: Yin Tianxiang , Liu Shixia , Xie Jingjing , Shen Weiguo
Published: January 2013

Heat capacities in the critical and the non-critical regions for {benzonitrile + tridecane} and {benzonitrile + pentadecane}, and light scattering for {benzonitrile + undecane}, {benzonitrile + dodecane}, {benzonitrile + tridecane}, {benzonitrile + tetradecane}, {benzonitrile + pentadecane}, and {benzonitrile + hexadecane} in the critical two-phase region were measured. Light scattering measurements confirmed the existence of the asymmetry for the osmotic compressibility while no such asymmetry was observed for the correlation length. An analysis of the osmotic compressibility asymmetry suggested the dominance of the singular term $| {\Delta \hat T} |^\beta$|ΔT̂|β, which supports the complete scaling theory. The consistency of the complete scaling theory in descriptions of different asymmetry behaviors was also discussed. Moreover, it was found that the contribution of the heat capacity-related term is also important in describing the asymmetry of the osmotic compressibility as it was observed in studies of the diameters of the coexistence curves.
Study of the formation of 3-D titania nanofibrous structure by MHz femtosecond laser in ambient air
Authors: Tavangar Amirhossein , Tan Bo , Venkatakrishnan K.
Published: January 2013

In this study, we describe the formation mechanism of web-like three-dimensional (3-D) titania nanofibrous structures during femtosecond laser ablation of titanium (Ti) targets in the presence of background air. First, we demonstrate the mechanism of ablation of Ti targets by multiple femtosecond laser pulses at ambient air in an explicit analytical form. The formulas for evaporation rates and the number of ablated particles, which is analogous to the deposition rate of the synthesized nanofibers, for the ablation by a single pulse and multiple pulses as a function of laser parameters, background gas, and material properties are predicted and compared to experimental results. Afterwards, the formation of nanofibrous structures is demonstrated by applying an existing simplified kinetic model to Ti targets and ambient conditions. The predicted theory provides nanofiber diameter dependency with the combination of laser parameters, target properties, and ambient gas characteristics. Experimental studies are then performed on titania nanofibrous structures synthesized by laser ablation of Ti targets using MHz repletion-rate femtosecond laser at ambient air. The models' predictions are then compared with the experimental results, where nanostructures with different morphologies are manufactured by altering laser parameters. Our results indicate that femtosecond laser ablation of Ti targets at air background yields crystalline titania nanostructures. The formation of crystalline titania nanostructures is preceded by thermal mechanism of nucleation and growth. The results point out that laser pulse repetition and dwell time can control the density, size, and pore size of the engineered nanofibrous structure. As the deposition rate of nanostructures is analogous to the ablation rate of the target, higher density of nanofibrous structure is seen at greater laser fluences. The predicted theory can be applied to predict ablation mechanism and nanofiber formation of different materials.
On the existence and multiplicity of one-dimensional solid particle attractors in time-dependent Rayleigh-Bénard convection
Authors: Lappa Marcello
Published: January 2013

For the first time evidence is provided that one-dimensional objects formed by the accumulation of tracer particles can emerge in flows of thermogravitational nature (in the region of the space of parameters, in which the so-called OS (oscillatory solution) flow of the Busse balloon represents the dominant secondary mode of convection). Such structures appear as seemingly rigid filaments, rotating without changing their shape. The most interesting (heretofore unseen) feature of such a class of physical attractors is their variety. Indeed, distinct shapes are found for a fixed value of the Rayleigh number depending on parameters accounting for particle inertia and viscous drag. The fascinating “sea” of existing potential paths, their multiplicity and tortuosity are explained according to the granularity of the loci in the physical space where conditions for phase locking between the traveling thermofluid-dynamic disturbance and the “turnover time” of particles in the basic toroidal flow are satisfied. It is shown, in particular, how the observed wealth of geometric objects and related topological features can be linked to a general overarching attractor representing an intrinsic (particle-independent) property of the base velocity field.
Criticality in conserved dynamical systems: Experimental observation vs. exact properties
Authors: Marković Dimitrije , Gros Claudius , Schuelein André
Published: January 2013

Conserved dynamical systems are generally considered to be critical. We study a class of critical routing models, equivalent to random maps, which can be solved rigorously in the thermodynamic limit. The information flow is conserved for these routing models and governed by cyclic attractors. We consider two classes of information flow, Markovian routing without memory and vertex routing involving a one-step routing memory. Investigating the respective cycle length distributions for complete graphs, we find log corrections to power-law scaling for the mean cycle length, as a function of the number of vertices, and a sub-polynomial growth for the overall number of cycles. When observing experimentally a real-world dynamical system one normally samples stochastically its phase space. The number and the length of the attractors are then weighted by the size of their respective basins of attraction. This situation is equivalent, for theory studies, to “on the fly” generation of the dynamical transition probabilities. For the case of vertex routing models, we find in this case power law scaling for the weighted average length of attractors, for both conserved routing models. These results show that the critical dynamical systems are generically not scale-invariant but may show power-law scaling when sampled stochastically. It is hence important to distinguish between intrinsic properties of a critical dynamical system and its behavior that one would observe when randomly probing its phase space.
Effects of hydrodynamic interaction on the equivalent conductivity minimum of electrolyte solutions in solvents of low dielectric constant
Authors: Yamaguchi T. , Shimoda Y. , Koda S.
Published: January 2013

Brownian dynamics simulation on model electrolyte solutions in our previous work [T. Yamaguchi et al., J. Chem. Phys. 134, 244506 (2011)]10.1063/1.3604532 is extended to include the hydrodynamic interaction between ions, in order to examine its effects on ionic mobility in solvents of low dielectric constant. The effects of the hydrodynamic interaction are rather small as a whole, and the equivalent conductivity minimum is observed in systems with the hydrodynamic interaction. The hydrodynamic interaction increases the self-diffusion coefficient while decreases the equivalent conductivity, thereby increases the deviation from the Nernst-Einstein relationship. Based on the analysis of the time-dependent ionic mobilities, these changes are elucidated in terms of the electrophoretic and relaxation effects. It is also demonstrated that the concentration dependence of the ionic mobilities with the hydrodynamic interaction is reproduced fairly well by a theoretical calculation.
Theoretical prediction of new carbon allotropes
Authors: Yang L. , He H. Y. , Pan B. C.
Published: January 2013

Novel carbon allotropes are predicted by optionally substituting carbon atoms in diamond with carbon tetrahedrons. All these allotropes exhibit semiconducting properties, with bandgaps ranging from 3.2 to 4.7 eV. The calculated cohesive energy, mass density, and the bulk modulus are essentially related with the component of the tetrahedron units in these allotropes. In particular, we reveal the evolution of mechanical and electronic properties with the component of tetrahedrons for this family of crystalline carbon allotropes. This sheds a new light of tuning electronic and elastic properties of new allotropes by controlling the composition of carbon tetrahedrons. In addition, the calculated Raman spectra for these allotropes exhibit different features, and Raman characteristic modes for the tetrahedron units are addressed, which are available for identifying these allotropes in experiment.
Development of a single-shot-imaging thin film for an online Thomson parabola spectrometer
Authors: Sakaki H. , Kanasaki M. , Fukuda Y. , Nishiuchi M. , Hori T. , Yogo A. , Jinno S. , Niita K.
Published: January 2013

A single-shot-imaging thin scintillator film was developed for an online Thomson parabola (TP) spectrometer and the first analysis of laser accelerated ions, using the online TP spectrometer, was demonstrated at the JAEA-Kansai Advanced Relativistic Engineering Laser System (J-KAREN). An energy spectrum of ∼4.0 MeV protons is obtained using only this imaging film without the need of a microchannel plate that is typically utilized in online ion analyses. A general-purpose Monte Carlo particle and heavy ion-transport code system, which consists of various quantum dynamics models, was used for the prediction of the luminescent properties of the scintillator. The simulation can reasonably predict not only the ion trajectories detected by the spectrometer, but also luminescence properties.
Hydrogenated K4 carbon: A new stable cubic gauche structure of carbon hydride
Authors: Lian Chao-Sheng , Wang Xin-Quan , Wang Jian-Tao
Published: January 2013

The structural and electronic properties of hydrogenated K4 carbon as a new cubic gauche structure in I213 symmetry are investigated using first-principles calculations. The total energy for this carbon hydride (labeled by K4-CH) is 0.47 eV per CH unit lower than that of solid molecular cubane, suggesting its energetic stability. Based on the calculated phonon dispersion curves and electronic band structure obtained by hybrid density functional method, we find that K4-CH is dynamically stable and exhibits as an insulator with an indirect band gap of 6.07 eV, which is close to 6.10 eV of cubic gauche nitrogen (cg-N). To study the doping effect of nitrogen, we have also investigated N-doped K4-CH with a composition of C4H4N4 in P213 symmetry. The phonon and electronic band structures show that it is dynamically stable and behaves as an insulator with an indirect band gap of 5.39 eV, smaller than that of both K4-CH and cg-N. These results broaden our understanding of the cubic gauche structure.
Exciton polaritons in semiconductor waveguides
Authors: Walker P. M. , Tinkler L. , Durska M. , Whittaker D. M. , Luxmoore I. J. , Royall B. , Krizhanovskii D. N. , Skolnick M. S. , Farrer I. , Ritchie D. A.
Published: January 2013

We report the observation of strong coupling between quantum well excitons and a guided mode of a semiconductor planar waveguide by observation of anticrossing in the dispersion. Strong spatial confinement of the optical mode allows a splitting between the two polariton modes of 5–6 meV for a single quantum well. Polaritons on resonance are shown to propagate with a characteristic decay length of 280 μm and a group velocity of 26 μm ps−1. This is a promising first step towards developing an alternative to microcavities for the study of rapidly propagating polaritons, which is particularly well suited to prospective on-chip polaritonic circuit applications.
Effect of filler auto-assembly on percolation transition in carbon nanotube/polymer composites
Authors: Combessis Anthony , Bayon Lorrène , Flandin Lionel
Published: January 2013

A series of composites with various content of multi-walled carbon nanotubes dispersed in polymer was tested for electrical properties. During isothermal annealing in the melt, dynamic percolation transition induced a tremendous increase in conductivity. The unstable structure also experienced a more than one order of magnitude reduction in percolation threshold. The insulator to conductor transition concurrently became softer, as revealed by a monotonous increase in the critical exponent, gradually departing from the universal value. These large and concomitant changes in percolation transition with annealing time were ascribed to the self-organization of the filler that favors the completion of the conductive network.
Ultrafast manipulation of near field coupling between bright and dark modes in terahertz metamaterial
Authors: Roy Chowdhury Dibakar , Singh Ranjan , Taylor Antoinette J. , Chen Hou-Tong , Azad Abul K.
Published: January 2013

We demonstrate ultrafast optical control of near field coupling between bright and dark mode resonances in metamaterials. The meta-molecule design consists of two orthogonally twisted resonators tightly coupled through near fields. We place ion implanted silicon patch with ultrafast carrier lifetime inside dark resonator split gap to achieve active control of its fundamental resonance that determines the near field coupling in the meta-molecule. Upon near infrared photoexcitation, we observed ultrafast dynamical transition of near field coupling between bright and dark resonators allowing the meta-molecule to change its state from coupled to decoupled and eventually back to the coupled state.