bluuebunny/crossref_metadata_2025 huggingface dataset:
Usability of virtual‐reality simulation training in obstetric ultrasonography: a prospective cohort study
Authors: Burden C. , Preshaw J. , White P. , Draycott T. J. , Grant S. , Fox R.
Published: January 2013

Objective

To assess the usability of virtual‐reality (VR) simulation for obstetric ultrasound trainees.

Methods

Twenty‐six participants were recruited: 18 obstetric ultrasound trainees (with little formal ultrasonography training) and eight certified experts. All performed five sequential VR‐simulated crown–rump length (CRL) scans in a single session and three repetitions of biparietal diameter (BPD), occipitofrontal diameter (OFD) and femur length (FL) measurements. Outcome measures included mean percentage deviation from target for all measurements. Time taken to perform each type of scan was recorded.

Results

The mean percentage difference for the first scan was significantly greater for the trainee group than for the expert group for BPD (P = 0.035), OFD (P = 0.010) and FL (P = 0.008) and for time taken for the first CRL (P < 0.001) and fetal biometry (including BPD, OFD and FL measurements) scan (P < 0.001), demonstrating that trainees were initially significantly less accurate and less efficient. Over subsequent scans, the trainees became more accurate for all measurements with a significant improvement shown for OFD and FL (P < 0.05). The time taken for trainees to complete CRL and fetal biometry scans decreased significantly (all P < 0.05) with repetition, to near‐expert efficiency.

Conclusions

All participants were able to use the simulator and produce clinically meaningful biometry results. With repetition, beginners quickly approached near‐expert levels of accuracy and speed. These data demonstrate that obstetricians with minimal experience can improve their ultrasonographic skills with short‐phase VR‐simulation training. The speed of improvement suggests that VR simulation might be useful as a warm‐up exercise before clinical training sessions in order to reduce their impact on clinical service. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.
Understanding palladium complexes structures and reactivities: beyond classical point of view
Authors: Derat Etienne , Maestri Giovanni
Published: January 2013

Palladium catalyzed cross‐coupling reactions are one of the most widely used class of transformation as shown by the Nobel prize awarded in 2010 to Heck, Negishi, and Suzuki. Computational chemistry has a long‐standing partnership with organometallics catalysis, especially with palladium. But even in a largely explored field, novelties can emerge from interplay between experiments and theory. Recent advances grounded on computational chemistry have shown that cooperative effect can explain reactivities; that despite the large number of well‐known Pd(0)/Pd(II) catalytic cycle, Pd(IV) is also a realistic intermediate in some cases; that noncovalent interactions can regulate selectivities. So, despite its wide use and recognition, palladium complexes are still full of surprises! WIREs Comput Mol Sci 2013, 3:529–541. doi: 10.1002/wcms.1137

This article is categorized under:

Electronic Structure Theory > Ab Initio Electronic Structure Methods
Two-loop RGEs with Dirac gaugino masses
Authors: Goodsell Mark D.
Published: January 2013

Abstract

The set of renormalisation group equations to two-loop order for general supersymmetric theories broken by soft and supersoft operators is completed. As an example, the explicit expressions for the RGEs in a Dirac gaugino extension of the (N)MSSM are presented.
Antioxidant Activity of Sesamin in Canola Oil
Authors: Si Wenhui , Xie Phil Fei , Ma Ka Ying , Liang Yintong , Wang Xiao Bo , Chung Hau Yin , Chen Zhen‐Yu
Published: January 2013

The present study presents the antioxidant activity of sesamin in canola oil compared with that of butylated hydroxytoluene (BHT) by monitoring the oxygen consumption and the decrease in linoleic acid and α‐linolenic acid. The oxidation of canola oil was conducted at 35, 60, 90, 120 and 180 °C with addition of 50–400 ppm sesamin. Results from the oxygen consumption test showed that sesamin dose‐dependently inhibited the oxidation of canola oil at concentrations of 50–200 ppm at temperatures of 60–180 °C, however, sesamin lost its antioxidant activity at a low temperature of 35 °C. The fatty acid analysis also demonstrated that sesamin at 50, 100 and 200 ppm dose‐dependently prevented the oxidation of linoleic acid and α‐linolenic acid in canola oil. Both the oxygen consumption and the fatty acid analysis demonstrated sesamin was less effective than BHT as an antioxidant at temperatures of 60–180 °C. It was therefore concluded that sesamin could prevent the lipid oxidation of frying fats and oil, however, its antioxidant activity was not as potent as that of BHT.
Current concepts in the treatment of adolescent femoroacetabular impingement
Authors: Ramachandran Manoj , Azegami Shin , Hosalkar Harish S.
Published: January 2013

There is growing evidence that symptomatic femoroacetabular impingement leads to intra-articular damage and the development of early-onset osteoarthritis. Symptoms of femoroacetabular impingement often do not manifest until adulthood, but have been increasingly recognised in the paediatric and adolescent population. The surgical treatment of femoroacetabular impingement is aimed at restoring a more normal femoral head–neck offset in order to increase the clearance and prevent femoral abutment against the acetabular edge. Current methods include open and arthroscopic techniques. The latter has been combined with an open approach to gain access to the head–neck junction for osteochondroplasty. Proximal femoral and/or periacetabular osteotomies are used to treat femoroacetabular impingement associated with deformity secondary to childhood hip conditions, such as slipped capital femoral epiphysis and Legg–Calvé–Perthes disease. Some adolescents have severe degenerative joint disease at the time of presentation and may require arthroplasty or arthrodesis. The aim of this review is to identify the major trends and advancements in the management of femoroacetabular impingement in adolescents, including the outcome of studies of the surgical treatment modalities used.
The role of stimulation parameters on the conditioned pain modulation response
Authors: Nahman-Averbuch Hadas , Yarnitsky David , Granovsky Yelena , Gerber Ezra , Dagul Pnina , Granot Michal
Published: January 2013

Background and purpose

Conditioned pain modulation (CPM) is a testing paradigm representing features of diffuse noxious inhibitory control. There is large diversity in the paradigms applied to induce CPM, and the consistency in CPM responses assessed by different paradigms is largely unknown. We aimed to characterize and explore the associations between the CPM responses assessed by different paradigms in the same cohort.

Methods

Thirty-three healthy middle-aged subjects underwent six CPM paradigms. The ‘test-stimuli’, consisted of thermal and mechanical modalities, using pain thresholds, suprathreshold pain and temporal summation types of measurements. The ‘conditioning-stimulus’ consisted of a contact heat stimulus applied to the thener of the left hand for 60s at an intensity of 46.5°C.

Results

Large variability was observed among the responses to the different CPM paradigms. Surprisingly, no correlations were found between the various CPM responses.

Conclusions

The variability in the CPM responses may suggest that the capacity of pain modulation is a multifaceted trait, whose expression varies with the application of different CPM paradigms.

Implications

Considering that CPM responses may represent different processes when assessed by different paradigms, we encourage the use of more than one CPM paradigm.
A salmon peptide diet alleviates experimental colitis as compared with fish oil
Authors: Grimstad Tore , Bjørndal Bodil , Cacabelos Daniel , Aasprong Ole G. , Omdal Roald , Svardal Asbjørn , Bohov Pavol , Pamplona Reinald , Portero-Otin Manuel , Berge Rolf K. , Hausken Trygve
Published: January 2013

Fish oil (FO) has been shown to have anti-inflammatory properties in animal models of inflammatory bowel disease, but how fish peptides (FP) influence intestinal inflammation has been less studied. Male Wistar rats, divided into five groups, were included in a 4-week dietary intervention study. Of the groups, four were exposed in the fourth week to 5 % dextran sulfate sodium (DSS) to induce colitis, while one group was unexposed. The diets were: (1) control, (2) control + DSS, (3) FO (5 %) + DSS, (4) FP (3·5 %) + DSS, (5) FO + FP + DSS. Following DSS intake, weight and disease activity index (DAI) were assessed, and histological combined score (HCS), selected colonic PG, cytokines, oxidative damage markers and mRNA levels were measured. FP reduced HCS, tended to lower DAI (P = 0·07) and reduced keratinocyte chemoattractant/growth-regulated oncogene levels, as compared with the FO diet. FP also reduced mRNA levels of Il-6 and Cxcl1, although not significantly. FO intake increased the DAI as compared with DSS alone. PGE3 levels increased after the FO diet, and even more following FO + FP intake. The FP diet seems to have a protective effect in DSS-induced colitis as compared with FO. A number of beneficial, but non-significant, changes also occurred after FP v. DSS. A combined FO + FP diet may influence PG synthesis, as PGE3 levels were higher after the combined diet than after FO alone.
The Martens Clause and the Laws of Armed Conflict
Authors: Ticehurst Rupert
Published: January 2013

The Martens Clause has formed a part of the laws of armed conflict since its first appearance in the preamble to the 1899 Hague Convention (II) with respect to the laws and customs of war on land:

“Until a more complete code of the laws of war is issued, the High Contracting Parties think it right to declare that in cases not included in the Regulations adopted by them, populations and belligerents remain under the protection and empire of the principles of international law, as they result from the usages established between civilized nations, from the laws of humanity and the requirements of the public conscience.”
The Haemogregarines of Mammals and Reptiles
Authors: Patton W. S.
Published: January 2013

In two recent papersm Sambon and Seligmann (1907, 1908) have recorded some observations on the intracellular parasites of snakes, and have described no less than ten new species. The authors, in discussing the life histories of these parasites, have made the startling discovery that, “the life history of the haemogregarines like that of the haemoprotozoa is divided into two cycles: a schizogonic or ‘vegetative’ cycle spent in the blood of vertebrates and characterised by asexual multiplication, and a sporogonic or sexual cycle spent in the digestive organs of blood-sucking invertebrates and characterised by sexual reproduction.” The authors then go on to speak quite familiarly of young merozoites, adult schizonts, adult sporonts, and so on.
XXIII.—On Problems connected with Item Selection and Test Construction
Authors: Lawley D. N.
Published: January 2013

9. A formula is adopted which gives the probability of an individual of given ability passing a test item in terms of two quantities constant for that item. A method of estimating these two constants is given. Making certain assumptions concerning the items composing a test, formula? are then derived giving the expected value and the standard error of the test score of any person. It is shown that there is a certain reciprocity between persons and items, and corresponding formula? are given for the item scores. Finally, the results are applied to actual data obtained on a Moray House intelligence test, an estimate being made of the reliability of the test.

In conclusion I should like to thank Professor Godfrey H. Thomson for his help and valuable criticism in connection with this paper. I should also like to take this opportunity of thanking the Carnegie Trust for the Universities of Scotland for grants to cover the cost of the setting and printing of mathematical formula? in two papers previously published in the Society's Proceedings.
Older women's reduced contact with food in the Changes Around Food Experience (CAFE) study: choices, adaptations and dynamism
Authors: LANE KATHLEEN , POLAND FIONA , FLEMING SHEILA , LAMBERT NIGEL , MACDONALD HILARY , POTTER JOHN , RAATS MONIQUE , SKIDMORE PAULA , VINCE CAROL , WELLINGS AMANDER , HOOPER LEE
Published: January 2013

Many older women reduce the amount of cooking and food preparation they do in later life. While cooking may be seen as traditionally associated with women's family roles, little is known about the impact of such reduced engagement with food on their lives. This paper presents the findings from a one-year qualitative study (Changes Around Food Experience, CAFE) of the impact of reduced contact with preparing and cooking meals from scratch for 40 women, aged 65–95 years, living in Norfolk, United Kingdom. Data were collected through semi-structured interviews, focus groups and observations. Women's reasons for reducing food-related activities included changes in health, loss of a partner or a caring role, and new patterns of socialising. Disengagement from cooking and shopping was not found to entail predominantly negative feelings, passive acceptance or searching for forms of support to re-enable more cooking from scratch. Accounts evidenced the dynamic adaptability of older women in actively managing changed relationships with food. In exploring new meal options, older women were not simply disengaging from their environments. CAFE findings linked women's engagement with their environments to how they were using formal services and, even more, to the value they placed on social engagement and being out and about. Through the connections they fostered with friends, family and community, older women actively enabled their continued involvement in their social, public and family spheres. Reduced contact with preparing and cooking meals from scratch, therefore, did not induce or imply passivity or debility in the CAFE cohort. By contrast, it involved their exploring new means of retaining what was important to them about food in the context of their lived situation and social connections with friends, family, the community and public spheres.
La influencia del ferrocarril en el desarrollo urbano español (1860-1910)
Authors: Barquín Rafael , Pérez Pedro , Sanz Basilio
Published: January 2013

The aim of this paper is to measure the influence of the railroad in the urbanization of Spain between 1860 and 1910. Our sources are from quantitative information –censuses of population– and qualitative one –coastal condition, existence of mining industry or industry, administrative capital and date of the railway connection–. We have estimated a first model of data panel in differences. Based on this model we have employed different estimation techniques in order to address omitted variables and/or endogeneity of the train variable. Results from all estimations give us clear evidence of the positive influence of the railroad on the urban growth. In addition a quasi-experiment design reinforces this conclusion. In short, although moderate, our paper shows strong evidence of the influence of the railroad on Spanish urbanization. This conclusion is coherent with other research.
The U.S. Church, the Secular World and the Temptation to “Integrism”
Authors: Lakeland Paul
Published: January 2013

Recent activity among the American Catholic bishops in the social and political arena shows in some cases at least a tendency towards the “heresy” of integrism as defined by Karl Rahner, namely, the inclination to see the ethical teaching of the Church as a blueprint or template for secular society. This article surveys some examples of this tendency. It argues for a vision of the secular world as independent and grace-filled. The constructive proposal towards which this article moves, which is an effort to place the Church's ethical outlook on the secular world in the space between integrism and esotericism, is worked out in dialogue with Rahner, Archbishop Charles Chaput, Archbishop Rowan Williams and Professor James Davison Hunter.
Christianity or Nihilism? The Apocalyptic Discourses of Johann Baptist Metz and Friedrich Nietzsche
Authors: Eggemeier Matthew
Published: January 2013

This paper explores the apocalyptic discourses of Johann Baptist Metz and Friedrich Nietzsche, examining in particular Metz's juxtaposition of Nietzsche's approach to time as eternal recurrence with biblical apocalyptic's approach to time with an end. While framing his criticism of Nietzsche in terms of these differing approaches to time, Metz's opposition focuses on Nietzsche's affirmation of even the most brutal experiences of suffering in the world as mere moments in the innocence of becoming. In contrast to attempts in Western thought to either justify (Leibniz, Hegel) or affirm (Nietzsche) suffering as a necessary byproduct of the creation of the best possible world (Leibniz), historical progress (Hegel), or the innocence of becoming (Nietzsche), Metz retrieves the biblical apocalyptic spirituality of protest, resistance, and political compassion as the authentic response to innocent suffering.
X-ray-diffraction study of solid C70
Authors: Narasimha Rao G. V. , Sastry V. S. , Premila M. , Bharathi A. , Sundar C. S. , Hariharan Y. , Seshagiri V. , Radhakrishnan T. S.
Published: January 2013

Precision X-ray powder-diffraction data of pure solid C70 is reported. C70 prepared by slow evaporation of C70-in-toluene solution adopts an hcp structure (space group P63/mmc) with lattice parameters a=10.5934(10)Å and c=17.262(2)Å.
Powder-diffraction solutions of the crystal structure of [Pd(NH4)3]C2O4
Authors: Solovyov L. A. , Blochina M. L. , Kirik S. D. , Blochin A. I. , Derikova M. G.
Published: January 2013

The crystal structure of [Pd(NH3)4]C2O4 was determined from X-ray powder data. The crystals are triclinic with unit-cell parameters: a=7.0807(7) Å, b=7.0806(7) Å, c=3.8011(5) Å, α=91.910(1)°, β=98.665(1)°, γ=97.283(1)°, S.G.=P−1, Z=1, V=187.11 Å3. All non-hydrogen atoms were located from the Patterson map. The structure was refined by the Rietveld technique: Rp−b=6.88, Rwp=6.51, RB=2.66. The crystal structure of [Pd(NH3)4]C2O4 is built from two types of elements: [Pd(NH3)4]2+ and C2O2−4. Cations [Pd(NH3)4]2+ form columns along c with distances (Pd–Pd)=3.8011 Å. C2O2−4 anions occupy places in the middle of the unit cell between layers of [Pd(NH3)4]2+. The compound is stable up to 200 °C and then decomposes, giving Pd powder.
New X-ray powder diffraction data for indium vanadium oxide InVO4-III
Authors: Touboul M. , Melghit K. , Denis S.
Published: January 2013

A precise X-ray powder diffraction pattern of the orthorhombic form of InVO4, InVO4-III, was obtained using a Huber camera with CuKα1 radiation (λ=1.5406 Å) and Si as internal standard (a= 5.4308 Å). Refinements of indexed reflections led to the following parameters: a=5.7531(3)Å, b=8.5201(4)Å, c=6.5781(3)Å, space group Cmcm, Z =4, Dx=4.733 g/cm3, Dm=4.65 g/cm3. The Smith–Snyder figure-of-merit is F30=201.4 (0.004, 34).
Crystalline structure of Ba2YCu0.25W0.75O6: A member of the new set of Ba2YzCuxW1−xO6 solid solutions
Authors: Bokhimi  , Morales A. , Garci´a-Ruiz A.
Published: January 2013

A model for the crystalline structure of Ba2YCu0.25W0.75O6 solid solution is given. The model proposed a perovskite ordered structure, with a cubic unit cell made from eight perovskite-like units and having a symmetry described by the space group Fm3m. The crystalline structure was refined by the Rietveld technique, giving RF=0.048 for 82 reflections. The solid solution was characterized by the following parameters: Z=4, Mr=613.2, a=8.43630(8) Å, V=600.42(1) Å3, Dx=6.78 g cm−3, μ=209.04 mm−1, and F(000)=1047. The model assumed that copper and tungsten atoms, which were ordered with Y atoms, had the same local environment. Therefore, it was only a first approximation to the crystalline structure.
A study of X-ray reflectivity data analysis methods for thin film thickness determination
Authors: Brower D. T. , Revay R. E. , Huang T. C.
Published: January 2013

The determination of thin film thickness by four X-ray reflectivity methods (namely, the peak separation, the Fourier transform, the modified Bragg equation, and the curve-fitting methods) has been studied. An analysis of SrS and BaF2 thin films showed thickness values determined by the methods agreed to within 4%. The curve-fitting method had the highest accuracy but was time-consuming. The peak separation, the Fourier transform, and the modified Bragg equation methods are considerably faster and, on average, gave 2.8%, 0.9%, and 0.2% larger thicknesses than those of the curve-fitting method.
An improved method for quantitative analysis of sedimentary minerals by X-ray diffraction
Authors: Chao Wang , Chunde Pan , Daqing Wang , Aixia Song , Jihong Nie , Shuhua Li
Published: January 2013

An improved backloading method to determine the reference intensity ratios of sedimentary minerals is presented. More than 50 reference intensity ratios of more than ten types of minerals formed in typical sedimentary environments were measured. Quantitative tests were performed on those minerals. Comparison of the results show that this method minimizes preferred orientation and improves quantitative precision (absolute deviation is less than 3%) so that it is an acceptable specimen loading method.
X-ray powder diffraction data of hauyne with incommensurate modulated structure from volcanic rocks of Laacher Lake, Germany
Authors: Sapozhnikov A. N. , Ivanov V. G. , Piskunova L. F. , Vasil'ev E. K.
Published: January 2013

Methods of the structure analysis were used to determine the incommensurate structure modulation in a sample of hauyne from Laacher Lake, Germany. The modulation parameter n=0.145, determined using single-crystal patterns, was refined using powder data. An indexing technique for additional reflections (satellites) using a parameter subcell and Miller index main reflections was suggested. Crystallographic characteristics of the hauyne of Laacher Lake are compared with that of hauyne from Sacrafano (Italy) and with lazurtes from Baikal, Pamir, and Afghanistan. We found that the crystal structure modulation can serve as a source of paragenesis information on sulphate bearing sodalte group minerals.
Experimental and calculated X-ray powder diffraction data for cesium titanium silicate, CsTiSi2O6.5: A new zeolite
Authors: McCready David E. , Balmer M. Lou , Keefer Keith D.
Published: January 2013

Standardized experimental and calculated X-ray powder diffraction data for a new synthetic zeolite, cesium titanium silicate, CsTiSi2O6.5, are reported. In addition, a structure model in space groupIa3d(230), which is isomorphous with the mineral pollucite (CsAlSi2O6·xH2O), is proposed for CsTiSi2O6.5. This structure model is the basis of the reported calculated X-ray powder diffraction data for CsTiSi2O6.5. The experimental pattern for CsTiSi2O6.5shows this compound crystallizes in a body-centered cubic (BCC) unit cell witha=13.8423 (1) Å. The measured value of the reference intensity ratio (I/Ic) of CsTiSi2O6.5is 2.37, while the contrasting calculated value ofI/Icis 4.45. The experimental density (Dm) of CsTiSi2O6.5is 3.48±0.09 g/cm3, in agreement with the calculated density (Dx) of 3.42 g/cm3. Chemical analysis of CsTiSi2O6.5by atomic absorption spectroscopy gives its composition as 54±2 wt% Cs; 23±2 wt% Ti; 23±2 wt% Si, which compares favorably with the theoretical composition of 56 wt% Cs; 20 wt% Ti; 24 wt% Si.
X-ray diffraction data for two new calcium uranium (VI) hydrates
Authors: Skakle J. M. S. , Moroni L. P. , Glasser F. P.
Published: January 2013

The X-ray powder diffraction patterns for two new synthetic calcium uranium (VI) silicate hydrate phases are reported. Ca1.5U6(OH)7O16·7H2O is orthorhombic, space groupP*a*, with unit cella=13.8949(14),b=12.0776(12),c=15.228(3) Å. The structure appears to be related to that of becquerelite. Ca2(UO2)2(Si2O5)3·10H2O was also indexed on an orthorhombic unit cell,a=12.075(3),b=15.406(6),c=26.043(6) Å. The Powder Diffraction File coverage of uranium-containing minerals which could, on the basis of their chemical formula, form in U-containing cements is also reviewed.
Powder diffraction data and Rietveld refinement of metastable t-ZrO2 at low temperature
Authors: Málek J. , Beneš L. , Mitsuhashi T.
Published: January 2013

Indexed X-ray powder diffraction data are reported for the low temperature tetragonal ZrO2 obtained by crystallization of zirconia gel. The structure was refined by the Rietveld technique on the basis of space group P42/nmc. Refined unit cell dimensions are a = 3.5984(5) Å, c = 5.152(1) Å, V = 66.71 Å3, Dx=6.135 g/cm3, F18=62 (0.012, 24), RP=8.99, Rwp=11.48, RB=3.13.
Improved powder X-ray data for Cancrinites III: Davyne
Authors: Ballirano Paolo , Maras Adriana , Buseck Peter R. , Yates Ann M.
Published: January 2013

New powder X-ray diffraction data of davyne, a member of the cancrinite group of minerals, were collected using a rotating anode diffractometer: the hexagonal cell parameters are a=12.6711(3) Å, c=5.3278(2) Å, volume 740.82(4) Å3 (space group P63). The strongest lines are: 3.658(100), 4.790(73), 3.272(70), 2.112(48), 2.438(22), 2.663(19), 1.781(19), and 4.147(17). The new data provide quantitative intensities improved precision in d-spacings and cover an increased 2θ angular range with respect to PDF 20-379. Measured intensities and a simulated pattern are reported together with crystal-chemical considerations.
Crystal and X-ray powder diffraction data for orthorhombic BaNd2Mn2O7 phase
Authors: Ueno Shunkichi , Kamegashira Naoki
Published: January 2013

A Rietveld refinement of X-ray powder diffraction data for orthorhombic BaNd2Mn2O7 is reported. The refined lattice parameters were a=0.5517(5), b=0.5482(3), and c=2.0585(7) nm with space group Fmmm (No. 69).
A series of “chemically twinned rutile” oxides, SrM2n+1O4n+5 (M=Ti, Nb; n=3→9)
Authors: Loezos J. M. , Vanderah T. A. , Drews A. R. , Roth R. S.
Published: January 2013

X-ray powder diffraction data and refined unit cell parameters for SrTi3Nb4O17, SrTi5Nb4O21, SrTi7Nb4O25, SrTi9Nb4O29, SrTi11Nb4O33, SrTi13Nb4O37, and SrTi15Nb4O41 are reported here. The powder patterns for these oxides suggest that they form a homologous series SrM2n+1O4n+5 (M=Ti, Nb; n=3→9), which is isostructural with the orthorhombic “chemically twinned rutile” series found previously in the K2O-TiO2-Ta2O5 and BaO-TiO2-Nb2O5 systems. The structures are built of corner-sharing slabs of the rutile structure; successive members are generated by adding 2TiO2 to the slab thickness of the previous member. The series crystallizes in space group Cmcm (No. 63), with members exhibiting similar a-, b-dimensions (∼6.6, ∼8.9 Å; respectively), and c-dimensions that linearly increase (by ∼4.4 Å per member) from 20.8 Å for n=3 to 47.1 Å for n=9.
Crystallographic data for BaMnSiO4: A new phase in the system BaO-MnO-SiO2
Authors: Nihtianova D. D. , Ivanov I. T. , Macicek J. J. , Georgieva I. K.
Published: January 2013

A new phase in the system BaO-MnO-SiO2 obtained by a pyrosynthetic method has been investigated using selected area electron diffraction (SAED), electron probe microanalysis (EPMA), and X-ray powder diffraction. The lattice parameters and a possible space group of the phase with a general composition BaMnSiO4 were determined as follows: a=5.370(2), b=18.447(7), c=8.498(5) Å, Z=8, Space Group Pmc21.
Initial Rietveld characterisation of biological calcifications
Authors: Rogers K. D.
Published: January 2013

X-ray diffraction data has been collected from biological calcific mineral associated with human bone, breast tissue, ureteric calculi, heart valve, and aorta. All the materials are shown to have a nominal calcium hydroxyapatite structure and Rietveld analysis has been performed to extract microstructural information. All refinements achieved a final Rwp value of <10%. The lattice parameter ranges are a=9.375(3)(breast)−9.4316(8)(heartvalve), c=6.866(1)(uretericcalculi) −6.899(1)(rib), and crystallite size range from 40 Å (breast) to 99 Å (ureteric calculi). A correlation between crystallite size estimates from this Rietveld analysis and line profile methods is demonstrated. The results are supported by an infrared study and previous data from alternative techniques. Thus, it is demonstrated that the microstructure of these materials may be characterised by application of the Rietveld method.
Powder diffraction data of SmBa4Cu3O8.5+δ
Authors: Zhu Y. T. , Baldonado P. S. , Peterson E. J. , Peterson D. E. , Mueller F. M.
Published: January 2013

Rietveld analysis of X-ray powder diffraction data was performed on SmBa4Cu3O8.5+δ, which was synthesized from precursors Sm2O3, BaO2, and CuO at 1000 °C in an oxygen atmosphere. SmBa4Cu3O8.5+δ has a cubic perovskite-related structure that is isostructural with YBa4Cu3O8.5+δ, and a doubled perovskite unit cell parameter of 8.177 90±0.000 04 Å.
Characterisation of K-doped Bi4V2O11 by combined XRD and EPMA: A cautionary tale
Authors: Lee C. K. , Coats A. M. , West A. R.
Published: January 2013

A comparison of X-ray powder diffraction and electron probe microanalyses on samples of Na- and K-doped Bi4V2O11 (BIMEVOX) solid electrolytes indicates some of the problems associated with using XRD to assess phase purity, especially in materials of variable composition such as BIMEVOXes. In this study both the Na- and K-doped materials appeared phase pure by XRD. EPMA indicated the Na-doped materials to be single phase with their expected compositions while the K-containing materials were not phase pure with very little K present in the main BIMEVOX phase.
New ternary compounds in the BaO:Fe2O3:TiO2 system: Ba2Fe2Ti4O13 (“2:1:4”), Ba3Fe10TiO20 (“3:5:1”), and Ba4Fe2Ti10O27 (“4:1:10”)
Authors: Loezos J. M. , Vanderah T. A. , Cline J. P.
Published: January 2013

X-ray powder diffraction data and refined unit cell parameters for three compounds found during experimental determination of the BaO:Fe2O3:TiO2 phase diagram are reported here. All three phases crystallize in space group C2/m (No. 12). Ba2Fe2Ti4O13 (“2:1:4”) is isostructural with K2Ti6O13 and Ba2ZnTi5O13: a=15.1939(9), b=3.8912(3), c=9.1244(5) Å, β=98.456(5)°; Z=2, ρcalc=4.890 g/cc. Ba3Fe10TiO20 (“3:5:1”) is structurally analogous to its aluminum congener Ba3Al10TiO20: a=15.336(1), b=11.7986(9), c=5.1700(4) Å, β=91.220(6)° (I2/m setting); Z=2, ρcalc=4.750 g/cc. Ba4Fe2Ti10O27 (“4:1:10”) is also isostructural with its aluminum analog Ba4Al2Ti10O27: a=19.799(1), b=11.4324(6), c=9.8936(6) Å, β=109.146(4)° (C2/m); Z=4, ρcalc=4.934 g/cc. The 2:1:4 and 3:5:1 compounds adopt open-framework type structures while the 4:1:10 phase exhibits an eight-layer close-packed arrangement.
Determining the crystal structure ofSr5(PO4)3Br, a new compound in the apatite series, by powder diffraction modeling
Authors: Nötzold Dagmar , Wulff Harm
Published: January 2013

Pentastrontium bromidephosphate,Sr5(PO4)3Br, was prepared by solid state reaction. The crystal structure of polycrystallineSr5(PO4)3Brwas refined from X-ray powder diffraction data by the Rietveld method using the structure model ofSr5(PO4)3Clsingle crystals.Sr5(PO4)3Bris isostructural withSr5(PO4)3Cl. The space group isP63/m. The cell parameters area0=9.9641(1) Å,c0=7.2070(1) Å, α=β=90°, γ=120°,Z=2,d(calc)=4.27g/cm3, andd(expt)=4.10g/cm3. Atomic parameters are given. Final values areRp=10.9%,Rwp=14.3%, andS=1.28. The figure of merit isF30=58 (0.013, 39).
Powder diffraction data for niobium IV hexafluorides: VNbF6 and CrNbF6
Authors: Goubard Fabrice , Bizot Daniel , Chassaing Jean
Published: January 2013

New hexafluoroniobates IV, VNbF6 and the high-temperature form of CrNbF6 have been synthesized by solid-state reaction. The former is isostructural with rhombohedral LiSbF6, space group R3¯, and the latter crystallizes with tetragonal symmetry, space group I/4mmm. Unit-cell parameters were determined: a=5.520(1) Å, c=13.987(5) Å, V=369.0(1) Å3, Z=3 for VNbF6, and a=5.5403(5) Å, c=8.453(1) Å, V=259.5(1) Å3, Z=2 for the “HT” form of CrNbF6. Powder diffraction data are reported.
Crystal data and X-ray powder diffraction data of two derivatives of 4-chloro-2,2′-iminodibenzoic acid: diethyl 4-chloro-2,2′-iminodibenzoate, C18H18ClNO4, and dimethyl 4-chloro-2,2′-iminodibenzoate, C16H14ClNO4
Authors: de Armas Héctor Novoa , Quevedo Armando Paneque , Martínez José Antonio Henao
Published: January 2013

Two derivatives of 4-chloro-2,2′-iminodibenzoic acid: diethyl 4-chloro-2,2′-iminodibenzoate, C18H18ClNO4, and dimethyl 4-chloro-2,2′-iminodibenzoate C16H14ClNO4, have been investigated by means of X-ray powder diffraction. The unit cell dimensions were determined from diffractometer methods, using monochromatic CuKα1 radiation, and evaluated by indexing programs. The monoclinic cell found for diethyl 4-chloro-2,2′-iminodibenzoate was a=21.332(3) Å, b=7.889(2) Å, c=10.156(2) Å, β=91.43(1)°, Z=4, space group P2 (No. 3), Pm (No. 6), or P2/m (No. 10), Dx=1.351 mg/m3. The cell found for this compound is in good agreement with the one obtained from single crystal X-ray diffractometry. The monoclinic cell found for dimethyl 4-chloro-2,2′-iminodibenzoate has the dimensions a=15.962(2) Å, b=5.151(2) Å, c=12.590(2) Å, β=98.35(1)°. Z=4, space group P2 (No. 3), Pm (No. 6), or P2/m (No. 10), Dx=2.073 mg/m3.
X-ray powder diffraction data and structural study of Fe2GeSe4
Authors: Henao J. A. , Delgado J. M. , Quintero M.
Published: January 2013

The room temperature X-ray powder diffraction pattern of Fe2GeSe4, a II2 □ IV VI4 semiconducting compound, has been recorded and evaluated. This material was found to be orthorhombic, a=13.069(1), b=7.559(1), c=6.2037(6) Å, V=612.83(9) Å3, Z=4, Dx=5.42 gcm−3. The structure refinement carried out using the Rietveld method indicated that this material crystallizes in space group Pnma (No. 62) with an olivine type of structure. The refinement of 33 parameters led to RWP=15.3%, RP=10.2% for 5251 step intensities and RB=9.44% and RF=9.36% for 913 reflections.
X-ray powder diffraction data and structural study of Cd4GeSe6
Authors: Henao J. A. , Delgado J. M. , Quintero M.
Published: January 2013

The X-ray powder diffraction pattern of the room temperature phase of Cd4GeSe6, a II4 □ IV VI6 semiconducting material, has been recorded and evaluated. This material crystallizes in the monoclinic space group Cc [No. 9] with a=12.847(3), b=7.407(2), c=12.854(2) Å, β=109.82(1)°, and Z=4. The powder diffraction pattern was also used to refine the crystal structure of this material employing the Rietveld method. The refinement of 56 parameters led to RWP=13.2%, RP=9.95% for 3751 step intensities and RB=7.05% and RF=5.20% for 833 reflections. Cd4GeSe6 can be considered a defect “adamantane-structure” material with a sphalerite-related superstructure.
Use of a high X-ray flux instrument for a mineral: X-ray powder diffraction pattern of CaMg(CO3)2
Authors: Suzuki Yoshikazu , Morgan Peter E. D. , Niihara Koichi
Published: January 2013

The usefulness of a high X-ray flux instrument to improve the accuracy of a powder diffraction pattern is demonstrated. In this case, very weak reflections of a well-characterized and well-known natural mineral can be detected by an often-used X-ray rotating anode diffractometer. High purity natural dolomite, CaMg(CO3)2, for example, was used to produce a slightly more comprehensive indexed X-ray powder diffraction. The powder pattern obtained in this study was compared with that of the reported high quality PDF pattern (36-426, with “*” mark) and that of a calculated pattern derived from single crystal structure data. A very weak 003 reflection at low angle and many weak reflections at high angles, not reported in the PDF pattern, were successfully identified using this high-power X-ray instrument. Unit cell parameters were determined to be a=4.8090±0.0001 Å and c=16.0182±0.0003 Å, which were in good agreement with the extant PDF pattern. Accuracy of the relative intensities between the measured and calculated patterns was apparently somewhat improved in this study, probably also attained through less preferred orientation and the higher purity of the sample used.
Synthesis and powder X-ray diffraction data of a new iron phosphate Fe(PO4)·0.5H2O
Authors: Ishizawa Nubuo , Saiki Atsushi , Ohdan Kyoji , Ai Mamoru
Published: January 2013

X-ray powder-diffraction data were collected for a new iron phosphate, Fe(PO4)·0.5H2O, obtained by reducing FePO4 with oxalic acid at 220 °C in the presence of water vapor and oxygen. The crystal system was determined to be orthorhombic with unit-cell parameters a=15.991(6) Å, b=20.156(7) Å, and c=7.223(2) Å.
X-ray powder diffraction study of K3H(SO4)2
Authors: Narasimha Rao G. V. , Sakuntala T.
Published: January 2013

The structure of K3H(SO4)2 is found to be monoclinic with space group C2/c based on analogy of the powder X-ray diffraction pattern with that of the Rb3H(SO4)2. The lattice parameters are a=14.6984(7), b=5.6840(2), c=9.7834(5) Å, and β=103.004(5)°, Vol=796.39(5); Dx=2.589 gcm−3, Z=4, and I/Icor=1.30.
Application of XRD in a rapid quality control system of cement
Authors: Goswami G. , Panda J. D.
Published: January 2013

The present paper establishes that the ratio between the XRD pulse counts of cement clinkers at d=0.278 and 0.274 nm bears a distinct relationship with the degree of sintering of the clinker, which is one of the factors that determine the cement quality. The paper also presents a rapid and accurate method for predicting both 3- and 28-day compressive strength (CCS) of cement mortar cubes based on XRD of the cement clinkers. The method is based on an index Xn derived from the XRD pulse counts at d=0.2959 and 0.287 nm corresponding to alite (hkl=202) and belite (hkl=102) phases of the clinker, respectively. The regression equation derived for a particular plant is (1) 3 day CCS=Xn×240 kg/cm2, when Xn<1 and 240+26 (Xn−1) kg/cm2, when Xn>1, where Xnmaximum=5.5. (2) 28 day CCS=C+C×In/100, where C=3 days CCS estimated by XRD (1), In=90−10Xn, where Xnmax=5.5. Calculated CCS values, in average, vary from the conventional test values by +5.9% to −5.4% and +3.8% to −3.5% in cases of 3- and 28-day CCS, respectively.
High temperature X-ray diffraction study of phase decomposition in rapidly quenched Al–Ge–Si
Authors: Mattern N. , Teresiak A. , Schubert T. , Löser W. , Doyle S.
Published: January 2013

The phase decomposition occurring during the heating of rapidly quenched Al–Ge–Si alloys has been investigated in situ by means of synchrotron radiation X-ray diffraction. The metastable Al–Ge phases formed in the as-quenched state transform during heating to Al and Ge. The addition of silicon decreases the transformation temperature. A Ge(Si) solid solution is indicated by a systematic change in the lattice constant of Ge as a result of the diffusion of Si from the Al matrix into the phase-separated Ge matrix.
Positional ordering in the light RE–Ga systems (RE=rare earth element)
Authors: Gur D. , Kimmel G.
Published: January 2013

Crystal data and results of structure refinement, using powder X-ray diffraction and Rietveld analysis, for ε-ordered structures near 75 at. % Ga are reported. The structures are based on the AlB2-type with deviation from stoichiometry due to pairwise substitution of rare earth (RE) atoms by gallium. Weak reflections which are forbidden in the AlB2-type structure were observed and indicate the existence of positional ordering of Ga2 pairs located in the basal planes preserving the hexagonal symmetry (S.G. P6/mmm). This ordering results in a new unit cell with parameters a′, c′, in which a′=a√3 and c′=c. The experimental data of the cells parameters are: a=7.467(2)Å, c=4.276(3)Å for Nd1−xGa2−x (x=0.18), and a=7.400(3)Å, c=4.184(2)Å for Gd1−xGa2+2x (x=0.165).
Powder diffraction data and Rietveld refinement of Hägg-carbide, χ-Fe5C2
Authors: Retief Johannes J.
Published: January 2013

The structure and powder diffraction data of Hägg-carbide (χ-Fe5C2) have been redetermined and improved by X-ray diffraction. Experimental values of 2θ, corrected for systematic errors, relative peak intensities, lattice spacings, and the Miller indices of 27 observed reflections up to 100° 2θ are reported. The unit cell is monoclinic (space groupC2/c,Z=4) witha=11.588 Å,b=4.579 Å,c=5.059 Å, and β=97.75°. The crystal structure has been refined by Rietveld analysis, resulting inRwp=0.073.
Crystal structure of 3-methoxybenzanthrone from X-ray powder diffraction
Authors: Yatsenko A. V. , Chernyshev V. V. , Zhukov S. G. , Sonneveld E. J. , Schenk H.
Published: January 2013

In the framework of the study of the relationship between crystal packing of solid dyes and their visible reflectance spectra, the crystal structure of 3-methoxy-7H-benz[de]anthracen-7-one (Disperse Yellow 13, C18H12O2) has been determined using a combined set of Bragg–Brentano diffractometer and Guinier–Johannson photographic data with the grid search procedure. Parameters of the orthorhombic cell (P212121, No.19, Z=4) at 295 K are a=15.265(9) Å, b=20.524(9) Å, c=3.990(2) Å. Rietveld refinement gave Rp=0.085, Rb=0.135. The molecules form stacks along [001] with an interplanar spacing of 3.46 Å.
Investigation of (Sr4−δCaδ)PtO6 using X-ray Rietveld refinement
Authors: Wong-Ng W. , Kaduk J. A. , Young R. A. , Jiang F. , Swartzendruber L. J. , Brown H. J.
Published: January 2013

The structures of the solid solution series (Sr4−δCaδ)PtO6, with δ=0, 0.85(1), 2, and 3, have been investigated using the Rietveld refinement technique with laboratory X-ray powder diffraction data. A complete solid solution between Sr and Ca was confirmed to exist. These compounds crystallize in the rhombohedral space group R3¯c. The cell parameters of the series range from a of 9.4780(3) to 9.7477(1) Å, and c from 11.3301(4) to 11.8791(1) Å for δ from 3 to 0, respectively. The structure consists of chains of alternating trigonal prismatic (Sr, Ca)O6 and octahedral PtO6 units running parallel to the c axis. These chains are connected to each other via a second type of (Sr, Ca) ions, which are surrounded by eight oxygens, in a distorted square antiprismatic geometry. As Ca replaced Sr in Sr4PtO6, it was found to substitute preferentially in the smaller octahedral (Sr, Ca)1 site (6a) rather than at the eight-coordinate (Sr, Ca)2 site (18e). There appears to be an anomaly of cell parameters a and c at the compound Sr3.15Ca0.85PtO6. Their dependence on Ca content changes at δ≈1.00, where the Ca has fully replaced Sr in the 6a site. The substitution of Sr by Ca reduced the average (Sr, Ca)1–O length from 2.411 to 2.311 Å and (Sr, Ca)2–O from 2.659 to 2.570 Å as the composition varied from Sr4PtO6 to SrCa3PtO6. Reference X-ray powder diffraction patterns were prepared from the Rietveld refinement results for these members of the solid solution series. Magnetic susceptibility measurements of three of the samples (δ=0, 0.85, 2) show electronic transitions at low temperatures.
Powder X-ray diffraction study of disilver(1+) pentacyanonitrosylferrate(2−)
Authors: Venegas V. , Gómez A. , Reguera E.
Published: January 2013

The crystal structure of disilver(1+) pentacyanonitrosylferrate(2−) was studied by X-ray powder diffraction. IR and Mössbauer spectroscopies, thermogravimetric analysis and density measurements were also carried out. This compound is monoclinic, and its lattice parameters are: a=10.986(3) Å, b=6.4080(10) Å, c=7.4545(19) Å, α=δ=90°, β=102.54°(2).
Crystal structure of an unusual corrosion deposit, bis(ethylammonium) tetrachloroiron(II)
Authors: Kaduk J. A. , Harper J. J.
Published: January 2013

An Fe-containing deposit isolated from a commercial plant was identified by indexing its powder diffraction pattern, using the NIST Crystal Data Identification File to locate an isostructural Mn compound, and carrying out a successful Rietveld refinement. The principal phase in the deposit was confirmed to be bis(ethylammonium) tetrachloroiron(II). This compound crystallizes in the orthorhombic space group Pbca, with a=7.3291(6), b=7.2603(6), c=21.7544(8) Å, V=1157.59(14) Å, and Z=4. The structure consists of single perovskitelike layers of corner-sharing FeCl6 octahedra parallel to the ab plane, separated by bilayers of ethylammonium cations. The octahedra are tilted 4.4° with respect to the c-axis, and the layers are ruffled. The compound was apparently formed by reaction of the ethylamine corrosion inhibitor with Fe from the steel process vessel and chloride in the process stream.
X-ray powder diffraction studies of fibrillar zinc trimolybdates ZnMo3O10·nH2O (n=3.75,5,10)
Authors: Łasocha Wiesław , Surga Wiesław , Rafalska-Łasocha Alicja
Published: January 2013

The X-ray powder diffraction data of polycrystalline fibrillar zinc trimolybdates ZnMo3O10·3.75H2O, ZnMo3O10·5H2O, and ZnMo3O10·10H2O, are reported. An uncommon diffraction pattern was recorded in the case of the “wet fibers” of ZnMo3O10·10H2O, which could be indexed assuming a model of parallel fibers with translation disorder along the fiber axis. The powder diffraction patterns, lattice parameters, space groups, and other data describing these compounds are presented in this paper.© 1999 International Centre for Diffraction Data.
Crystal and molecular structure of 1-amino-4-methoxycarbonyl-3-methyl-8-oxopyrazolo[1,5-a]pyrimidine monohydrate from laboratory powder data
Authors: Chernyshev V. V. , Yatsenko A. V. , Tafeenko V. A. , Sonneveld E. J. , Schenk H. , Makarov V. A.
Published: January 2013

The crystal structure of 1-amino-4-methoxycarbonyl-3-methyl-8-oxopyrazolo[1,5-a]pyrimidine monohydrate,C9H10N4O3·H2O, from the family of pyrazolo[1,5-a]pyrimidines which demonstrate an activity against the influenzavirusAand coxsackievirusB3, has been determined from laboratory (Guinier-Johannson photograph) powder diffraction data using a grid search procedure. Parameters of the monoclinic cell (P21/a, No. 14,Z=4) at 295 K area=11.599(7) Å,b=11.550(7) Å,c=8.575(5) Å, β=110.76(4)°. Rietveld refinement (full-pattern-decomposition) gave χ2=4.8(4.5),Rp=0.048(0.043),Rwp=0.065(0.062). The observed microstrain-induced anisotropy of diffraction line broadening was approximated by a quartic form inh,k,l. The obtained results allowed to distinguish between several isomers which were indistinguishable by others methods.
Wavelet denoising of powder diffraction patterns
Authors: Smrčok Ľubomír , Ďurík Marián , Jorík Vladimír
Published: January 2013

Four powder diffraction patterns taken under different experimental conditions were denoised by a new method, i.e., thresholding of wavelet coefficients. The patterns were transformed by discrete wavelet transform applying Coiflet4 wavelet function. WLS refinements of peaks’ positions, FWHM, and intensity showed that wavelet denoising, in contrast to previously used polynomial smoothing, did not shift the maxima and preserved peak and integrated intensities. This method may therefore represent an useful alternative to polynomial filters or filters based on Fourier transform.
Lattice metric singularities and their impact on the indexing of powder patterns
Authors: Mighell Alan D.
Published: January 2013

A lattice metric singularity occurs when unit cells defining two (or more) lattices yield the identical set of unique calculated d-spacings. The existence of such singularities, therefore, has a practical impact on the indexing of powder patterns. For example, when experimental data from ζ-LiBO2 were indexed, two solutions (a rhombohedral and a monoclinic lattice) with approximately the same figure of merit were found. These two lattices yield the same set of unique d-spacings even though they are characterized by different reduced cells with cell volumes in the ratio 2 to 1. From the indexing point of view, both answers are correct. A singularity of this type is common and not a mathematical rarity. In fact, any rhombohedral cell of this kind has a derivative monoclinic subcell, each of which gives the same set of unique calculated d-spacings. In actual cases like this, one can run into a trap. Due to experimental error and input parameters, an indexing program may determine only one of the cells with a high figure of merit. When this happens, it is critical to recognize that another solution exists, especially if one has determined the lower symmetry lattice.