bluuebunny/crossref_metadata_2025_split huggingface dataset:
From structure topology to chemical composition. XII. Titanium silicates: the crystal chemistry of rinkite, Na2Ca4REETi(Si2O7)2OF3
Authors: Cámara F. , Sokolova E. , Hawthorne F. C. 
Published: December 2011

AbstractRinkite, ideallyNa2Ca4REETi(Si2O7)2OF3, is a common mineral in alkaline and peralkaline rocks. The crystal structures of five rinkite crystals from three alkaline massifs: Ilimaussaq, Greenland; Khibiny, Kola Peninsula, Russia and Mont Saint-Hilaire, Canada, have been refined as two components related by the TWIN matrix (–1 0 0, 0 –1 0, 1 0 1)(Mo-αaradiation). The crystals,a =7.4132-7.4414,b =5.6595-5.6816,c =18.8181-18.9431 Å, β = 101.353-101.424(2)°,V=776.1-786.7 Å3, space groupP21lc, Z =2,Dcalc= 3.376—3.502 g cm–3, were analysed using an electron microprobe subsequent to collection of the X-ray intensity data. Transmission electron microscopy confirmed the presence of pseudomerohedral twinning in rinkite crystals. The crystal structure of rinkite is a framework of TS (titanium silicate) blocks. The TS block consists of HOH sheets (H-heteropolyhedral, O-octahedral). The TS block in rinkite exhibits linkage and stereochemistry typical for Group I (Ti = 1 a.p.f.u.) of Ti disilicate minerals: two H sheets connect to the O sheet such that two (Si2O7) groups link to thetransedges of a Na polyhedron of the O sheet. The crystal chemistry of rinkite and nacareniobsite-(Ce) is discussed.
Jarosite–butlerite intergrowths in non-stoichiometric jarosites: crystal chemistry of monoclinic natrojarosite–hydroniumjarosite phases
Authors: Grey I. E. , Scarlett N. V. Y. , Bordet P. , Brand H. E. A. 
Published: December 2011

AbstractMonoclinic, non-stoichiometric natrojarosite—hydroniumjarosite solid solution phases have been synthesized hydrothermally over a range of temperatures, starting compositions and reaction times, and have been characterized using Rietveld refinement of synchrotron X-ray diffraction data, and chemical and thermal analyses. The H atom locations have been obtained from refinement of neutron diffraction data on a deuterated sample. The results confirm a direct relationship between the monoclinic distortion and the ordering of iron site vacancies in one of two independent iron sites. Ordering of iron vacancies gives rise to domains containing butlerite-like 7 Å chains of corner-connected octahedra and tetrahedra. The formation of these chains within (100) planes results in an expansion of the monoclinic a lattice parameter and a contraction of the c parameter relative to stoichiometric jarosites. The results support a recent model for iron deficiency, whereby an iron vacancy is compensated by the replacement of four coordinated OH– ions by H2O molecules, with one of the H2O molecules coming from deprotonation of H3O+. The general formula, based on intergrowth of stoichiometric jarosite and non-stoichiometric, butlerite-like regions, is [(Na,H3O)Fe3(SO4)2(OH)6]1–y[(H2O)Fe2(SO4)2(OH)2(H2O)4]y.
The crystal structure of gatehouseite
Authors: Elliott P. , Pring A. 
Published: December 2011

AbstractThe crystal structure of the manganese phosphate mineral gatehouseite, ideally Mn52+(PO4)2(OH)4, space groupP212121,a =17.9733(18),b =5.6916(11),c =9.130(4) Å,V=933.9(4) Å3,Z =4, has been solved by direct methods and refined from single-crystal X-ray diffraction data(T =293 K) to anRindex of 3.76%. Gatehouseite is isostructural with arsenoclasite and with synthetic Mn52+(PO4)2(OH)4. The structure contains five octahedrally coordinated Mn sites, occupied by Mn plus very minor Mg with observed <Mn—O> distances from 2.163 to 2.239 Å. Two tetrahedrally coordinated P sites, occupied by P, Si and As, have <P—O> distances of 1.559 and 1.558 Å. The structure comprises two types of building unit. A strip of edge-sharing Mn(O,OH)6octahedra, alternately one and two octahedra wide, extends along [010]. Chains of edge- and corner-shared Mn(O,OH)6octahedra coupled by PO4tetrahedra extend along [010]. By sharing octahedron and tetrahedron corners, these two units form a dense three-dimensional framework, which is further strengthened by weak hydrogen bonding. Chemical analyses by electron microprobe gave a unit formula of (Mn4.99Mg0.02)Σ5.01(P1.76Si0.07(As0.07)Σ2.03O8(OH)3.97.
Cossaite, (Mg0.5,☐)Al6(SO4)6(HSO4)F6·36H2O, a new mineral from La Fossa crater, Vulcano, Aeolian Islands, Italy
Authors: Demartin F. , Gramaccioli C. M. , Campostrini I. , Castellano C. 
Published: December 2011

AbstractCossaite, ideally (Mg0.5,☐)Al6(SO4)6(HSO4)F6·36H20, was found in the altered pyroclastic breccia of an active fumarole (T about 350°C) located at the rim of the La Fossa crater, Vulcano Island, Aeolian archipelago, Sicily, Italy. Cossaite is trigonal, space group R3̄, with a = 22.010(2), c = 9.238(1) Å, V = 3875.6(6) Å3, Z = 3. It forms stout prismatic hexagonal crystals up to 100 μm in size, terminated by rhombohedral faces, and is associated with thermessaite, vlodavetsite, sassolite and salammoniac. Cossaite is colourless to white, the streak is white and the lustre vitreous. It is not fluorescent in either long-wave or short-wave ultraviolet radiation. The calculated density is 2.075 g cm–3. The mean refractive index nobs is 1.49(1) (589 nm). Chemical analysis gave MgO 1.4, A12O3 19.5, SO3 34.7, F 5.7, (H2O 40.85, from structure refinement), O=F –2.4, total 99.75 wt.%, corresponding to the empirical formula Mg0.56Al6.19S7.01H73.37F4.85O65.15 calculated on the basis of 70 oxygen plus fluorine atoms. The strongest six lines in the X-ray powder diffraction pattern [dobs(Å) (I) (hkl)] are: 4.15 (100) (140), 3.87 (70) (32̄2), 11.00 (50) (110), 4.58 (25) (131), 2.770 (20) (3̄33), 2.166 (20) (1̄8̄1). The crystal structure was refined to a final R index of 0.0349. It contains octahedral [A1(H2O)5F]2+ cations and sulphate anions interacting via hydrogen bonds to form channels running along [001], where disordered [Mg(H2O)6]2+ cations and hydrogensulphate anions are hosted.
Anorpiment, As2S3, the triclinic dimorph of orpiment
Authors: Kampf A. R. , Downs R. T. , Housley R. M. , Jenkins R. A. , Hyršl J. 
Published: December 2011

AbstractThe new mineral anorpiment, As2S3, the triclinic dimorph of orpiment, has space group PI and cell parameters a = 5.7577(2), b = 8.7169(3), c = 10.2682(7) Å, α = 78.152(7), β = 75.817(7), γ = 89.861(6)°, V = 488.38(4) Å3 and Z = 4. It occurs at the Palomo mine, Castrovirreyna Province. Huancavelica Department, Peru. It is a low-temperature hydrothermal mineral associated with dufrenoysite, muscovite, orpiment, pyrite and realgar. It occurs in drusy crusts of wedge-shaped, transparent, greenish yellow crystals. The streak is yellow. The lustre is resinous on crystal faces, but pearly on cleavage surfaces. The Mohs hardness is about VA. The mineral is sectile with an irregular fracture and one perfect and easy cleavage on ﹛001﹜. The measured and calculated densities are 3.33 and 3.321 g cm–3, respectively. All indices of refraction are greater than 2. The mineral is optically biaxial (—) with 2V = 35—40° and no observed dispersion. The acute bisectrix (X) is approximately perpendicular to the ﹛001﹜ cleavage. Electron microprobe analyses yielded the averages and ranges in wt.%: As 58.21 (57.74–59.03), S 38.72 (38.33–39.00), total 96.94 (96.07–97.75), providing the empirical formula (based on 5 atoms) As1.96S3.04. The strongest powder X-ray diffraction lines are [d (hkl) I] 4.867(002) 97, 4.519 (110,11̄1) 77, 3.702 (1̄1̄1) 46, 3.609 (022,11̄2) 82, 2.880(201,02̄2,1̄2̄1,023) 75, 2.552 (1̄13,1̄31,132) 100, 2.469 (114,130,13̄1) 96. The structure of anorpiment [R1 = 0.021 for 1484 reflections with F0 > 4σ(F)] consists of layers of covalently bonded As and S atoms. Each S atom bonds to two As atoms at As—S—As angles between 100.45 and 104.15°. Each As atom is strongly bonded to three S atoms at S—As—S angles between 91.28 and 103.59°, forming an AsS3 pyramid with As at its apex. The As—S linkages within the layers form rings of six AsS3 pyramids. Interlayer bonding forces are interpreted as van der Waals. The structure of anorpiment is similar to that of orpiment in that it is composed of layers of As2S3 macromolecules, but arranged in a different stacking sequence.
Occurrence, composition and paragenesis of the zeolites and associated minerals in the alkaline basalt of a maar-type volcano at Haláp Hill, Balaton Highland, Hungary
Authors: Kónya P. , Szakáll S. 
Published: December 2011

AbstractHaláp Hill is an eroded remnant of young (∼3 Ma) alkaline basalt in the western part of the Bakony–Balaton Highland Volcanic Field, Tapolca, Hungary. Cavities in the basalt contain miarolitic minerals (augite, apatite, magnetite, plagioclase and sanidine), zeolites (analcime, chabazite-Ca, chabazite-Na, garronite, gismondine, gmelinite-Ca, gmelinite-Na, gobbinsite, gonnardite-Na, natrolite, mesolite, phillipsite-Ca, phillipsite-K, phillipsite-Na and scolecite) and other secondary minerals (calcite, smectite-group minerals, goethite and Mn-oxides). Chabazite-Na, gmelinite-Ca, gonnardite-Na, phillipsite-Na and phillipsite-K are reported from Haláp Hill for the first time. The Ca-rich and Na-rich zeolites and abundant calcite were produced by hydrothermal alteration. Mineral assemblages were characterized by X-ray diffraction, differential thermal analysis, energy-dispersive spectrometry and wavelength-dispersive spectrometry. The secondary mineral assemblages were probably formed as a result of low-temperature hydrothermal activity at 50—100°C. Miarolitic minerals crystallized first in cavities in the basalt; they were followed by zeolite-group minerals and calcite. Analcime and phillipsite with or without chabazite/gmelinite/garronite or gobbinsite were the first zeolite-group minerals to crystallize; gonnardite-Na and natrolite crystallized later from Na-rich fluids. Calcite and smectite-group minerals crystallized continually. This paragenetic sequence is similar to others which have been reported in basalt from other localities in the Balaton Highland, Iceland and Northern Ireland.
Fatigue Crack Closure at Near-Threshold Growth Rates in Steels, Effects of Microstructure, Load Sequence and Environment
Authors: Schaper Michael K. 
Published: December 2011

Abstract
This paper summarizes long-term research on fatigue crack closure in several labs of the author. Various experimental techniques were used in different combinations. Primarily, a sophisticated dynamic compliance technique based on highly sensitive resonance vibration measurements and crack tip diffracted ultrasonic wave analysis is applied. Whereas the first method reflects the global through thickness behavior, the second method enables spatial resolution, which is achieved with a reduction of sensitivity yet has the advantage that the signal generation is independent on the stress state ahead of the crack tip. The results allow a coherent view into the effects of the stress state, material plasticity, fracture surface roughness, and oxidation tendency on the closure behavior and, therefore, on both the threshold stress intensity and near-threshold crack propagation. Specifically, the different load ratio, load sequence, and the environmental effects on the threshold values of ferritic, martensitic, and austenitic steels are addressed.
Wear of Mobile Bearing Knees: Is It Necessarily Less?
Authors: Haider Hani , Kaddick Christian 
Published: December 2011

Abstract
Some well-known mobile bearing designs have had truly excellent long-term clinical results. Their lower constraint and ability for some self-alignment might have helped reduce the shear forces and torques transmitted to the prosthesis–bone interface, thereby lowering the risk of loosening. However, the most commonly assumed benefit of mobile bearings is the reduction in wear due to less contact stress and reduced cross shear. In a rotating platform, wear can be reduced because the rolling/sliding motion is separated from the transverse rotational motion, which reduces cross-shear. Although it has not been categorically proven clinically, such lower wear expectations with mobile bearings might have influenced the thinking of some total knee replacement (TKR) designers and test engineers. This paper amalgamates invitro TKR wear results from two separate laboratories (in Nebraska and Germany) to present the largest data set ever published on wear, across the widest variety of fixed and mobile bearing TKR designs. Many hundreds of TKR samples were tested with largely similar methodologies using the ISO 14243-1 force-control method. These tests covered 133 different fixed and mobile bearing designs and materials, in total (bicondylar) and unicompartmental forms, and of a wide range of sizes. Clear differences in wear resulted with known superior bearing materials. This illustrates how sensitive and capable of discriminating between low and high wearing implants the force-control wear testing methodology is. However, between both labs, and across all tests, no statistically significant differences were found in wear overall between fixed and mobile bearings. Therefore, the wear of mobile bearing knees is not necessarily less than that of fixed bearings. In both, it depends on the detailed design and materials of the TKR. Testing appears to be necessary with all implant designs, regardless of the history of clinically successful predicates of seemingly similar generic design.
Inconsistencies in Guidelines for Visual Health Surveillance of VDT Workers
Authors: SeguÍ María del Mar , Ronda Elena , Wimpenny Peter 
Published: December 2011

Inconsistencies in Guidelines for Visual Health Surveillance of VDT Workers: María del Mar SEGUÍ, et al. Optic, Pharmacology and Anatomy Department, Public Health Research Group, University of Alicante, Spain—ObjectivesIn Europe, 25% of workers use video display terminals (VDTs). Occupational health surveillance has been considered a key element in the protection of these workers. Nevertheless, it is unclear if guidelines available for this purpose, based on EU standards and available evidence, meet currently Accepted quality criteria. The aim of this study was to appraise three sets of European VDT guidelines (UK, France, Spain) in which regulatory and evidence based approaches for visual health have been formulated and recommendations for practice made.MethodsThree independent appraisers used an adapted AGREE instrument with seven domains to appraise the guidelines. A modified nominal group technique approach was used in two consecutive phases: first, individual evaluation of the three guidelines simultaneously, and second, a face‐to‐face meeting of appraisers to discuss scoring. Analysis of ratings obtained in each domain and variability among appraisers was undertaken (correlation and kappa coefficients).ResultsAll guidelines had low domain scores. The domain evaluated most highly was Scope and purpose, while Applicability was scored minimally. The UK guidelines had the highest overall score, and the Spanish ones had the lowest. The analysis of reliability and differences between scores in each domain showed a high level of agreement.ConclusionsThese results suggest current guidelines used in these countries need an update. The formulation of evidence‐base European guidelines on VDT could help to reduce the significant variation of national guidelines, which may have an impact on practical application.
Advances of Polymer Flood in Heavy Oil Recovery
Authors: Gao Chang Hong 
Published: December 2011

Abstract
The heavy oil resources worldwide are estimated at 3396 billion barrels. With depletion of light oil, we have to face the technical and economical challenges of developing heavy oil fields. The recovery of heavy oil reservoirs is often less than 20%, or even below 10%. Even though thermal methods have been successfully applied to many heavy oil fields, thin pay zones are not suitable for thermal recovery.
Based on past experiences, polymer flood is not recommended for oil viscosity over 100 centipoises. In recent years, polymer flood becomes a promising technology for heavy oil recovery thanks to the widespread use of horizontal wells. This paper highlights the research advances in polymer enhanced heavy oil recovery since 1977. Based on laboratory tests, polymer can achieve tertiary recovery of more than 20% for heavy oil. A few field cases in China, Canada, Turkey, Suriname and Oman are reviewed and analysed. Some field pilots have shown positive results.
Economic Decision-Making in Poverty Depletes Behavioral Control
Authors: Spears Dean 
Published: December 2011

Abstract
Economic theory and conventional wisdom suggest that time preference can cause or perpetuate poverty. Might poverty also or instead cause impatient or impulsive behavior? This paper reports a randomized lab experiment and a partially randomized field experiment, both in India, and analysis of the American Time Use Survey. In all three studies, poverty is associated with diminished behavioral control. The primary contribution of this empirical paper is to isolate the direction of causality from poverty to behavior. Three similar possible theoretical mechanisms, found in the psychology and behavioral economics literatures, cannot be definitively separated. One supported theoretical explanation is that poverty, by making economic decision-making more difficult, depletes cognitive control.
Information Precision and Manipulation Incentives
Authors: Drymiotes George C. 
Published: December 2011

ABSTRACT
Recent corporate governance failures have prompted regulators and legislators to introduce new rules and legislation aimed at improving corporate governance. In this paper, I highlight a potential unintended consequence of such actions by showing that increasing oversight may sometimes be the catalyst for more manipulation. The key behind this result is the managers' potential ability to undermine oversight through manipulation choices. Absent an interaction between manipulation choices and oversight efficacy, increasing oversight results in less manipulation.
JEL Classifications: D80; G34; M40.
A Social Network Analysis of the Literature on Management Control
Authors: Euske Kenneth J. , Hesford James W. , Malina Mary A. 
Published: December 2011

ABSTRACT
This paper investigates the literature on management control published in accounting and management journals. Social network analysis of citation data from the 25-year period 1981–2005 enables us to examine topics and ties among researchers. Social ties have important consequences for the development of the literature, shaping topics, research methods, and the diffusion of knowledge. We observe minimal communication between the two disciplines, appearing as two distinct communities despite similar interests. This lack of communication includes citations and authoring across the two disciplines. When citations across disciplines occur, it is almost exclusively accounting authors citing management authors, not vice versa. There is virtually no joining of accounting and management scholars within social networks. Within the two broader communities, there also exist smaller research clusters. While we cannot determine the impact this has on our understanding of management control, we discuss possible reasons for this phenomenon and its potential implications for management control research.
Data Availability: Data were gathered from publicly available sources.
DISCUSSION OF: Examining Shareholder Value Creation over CEO Tenure: A New Approach to Testing Effectiveness of Executive Compensation
Authors: Weiss Dan 
Published: December 2011

ABSTRACT
The executive compensation literature has explored the executive pay-for-performance relation in various contexts and reported mixed findings. As a result, the question of whether executive incentives, and particularly stock options, are effective continues to pose a puzzle to researchers. Gong (2011) uses a long window to examine effectiveness of executive compensation. This note discusses several broad aspects of pay-for-performance studies and their potential manifestation in this line of research and in Gong's study. Specifically, I elaborate on measurement issues and on each of the following aspects: (1) the underlying paradigm: arm's-length contracting versus managerial power; (2) the distinction between the pay-for-performance relationship and CEO overpay; (3) market efficiency; and (4) the settling-up problem.
Managing Planning and Production Moral Hazard
Authors: Lin Haijin H. , Sappington David E. M. 
Published: December 2011

ABSTRACT
We characterize the optimal policy to induce a manager to assess the merits of a potential investment project, decide whether to implement the project, and enhance the performance of the project if it is implemented. We find that the initial planning moral hazard problem often is more constraining than the subsequent production moral hazard problem. To mitigate the planning moral hazard problem, under-investment is optimally induced when the project is initially thought to be profitable, whereas over-investment is induced when the project is initially thought to be unprofitable.
Transcendence degree of zero-cycles and the structure of Chow motives
Authors: Gorchinskiy Sergey , Guletskiĭ Vladimir 
Published: December 2011

Abstract
In the paper we introduce a transcendence degree of a zero-cycle on a smooth projective variety X and relate it to the structure of the motive of X. In particular, we show that in order to prove Bloch’s conjecture for a smooth projective complex surface X of general type with p
g = 0 it suffices to prove that one single point of a transcendence degree 2 in X(ℂ), over the minimal subfield of definition k ⊂ ℂ of X, is rationally equivalent to another single point of a transcendence degree zero over k. This can be of particular interest in the context of Bloch’s conjecture for those surfaces which admit a concrete presentation, such as Mumford’s fake surface, see [Mumford D., An algebraic surface with K ample, (K
2) = 9, p
g = q = 0, Amer. J. Math., 1979, 101(1), 233–244].
Interaction between plant polyphenols and the erythrocyte membrane
Authors: Cyboran Sylwia , Oszmiański Jan , Kleszczyńska Halina 
Published: December 2011

AbstractThe purpose of these studies was to determine the effect of polyphenols contained in extracts from apple, strawberry and blackcurrant on the properties of the erythrocyte membrane, treated as a model of the biological membrane. To this end, the effect of the substances used on hemolysis, osmotic resistance and shape of erythrocytes, and on packing order in the hydrophilic region of the erythrocyte membrane was studied. The investigation was performed with spectrophotometric and fluorimetric methods, and using the optical microscope. The hemolytic studies have shown that the extracts do not induce hemolysis at the concentrations used. The results obtained from the spectrophotometric measurements of osmotic resistance of erythrocytes showed that the polyphenols contained in the extracts cause an increase in the resistance, rendering them less prone to hemolysis in hypotonic solutions of sodium chloride. The fluorimetric studies indicate that the used substances cause a decrease of packing order in the hydrophilic area of membrane lipids. The observations of erythrocyte shapes in a biological optical microscope have shown that, as a result of the substances’ action, the erythrocytes become mostly echinocytes, which means that the polyphenols of the extracts localize in the outer lipid monolayer of the erythrocyte membrane. The results obtained indicate that, in the concentration range used, the plant extracts are incorporated into the hydrophilic area of the membrane, modifying its properties.