bluuebunny/crossref_metadata_2025 huggingface dataset:
Wo lag das neutestamentliche Emmaus (Lukas 24,13)?
Authors: Riesner Rainer
Published: March 2008

The location of Emmaus named in the Gospel of Luke is discussed. The article argues against the hypothesis of C.P. Thiede who proposed that Emmaus should be identified with Moza-Kalonije. The mention of this place as Ammaous in the manuscript tradition of Flavius Josephus is only a secondary varia lectio. In the Early Christianity Moza-Kalonije was never connected with the tradition of the Gospel of Luke. The small city of Nikopolis/Amwas, however, was considered as the place named by the Gospel of Luke from the 3rd century onwards. Perhaps the mention in the fragments of the Chronographiae of Julius Africanus hints to the fact that this is an old tradition, belonging perhaps to the 1st century. That Emmaus is named κώμη in Luke 24,13.28 is not a strong classification (in opposition to town), but only a current title of a smaller settlement. For the distance between Jerusalem and Nikopolis/Amwas the varia lectio of 60 stadia could be the older one, later corrected to 160 stadia. In any case, it is possible to reach even Nikopolis/Amwas during one day by foot.
Diatessaron-Zitate bei Theodor von Mopsuestia?
Authors: Gerber Simon
Published: March 2008

This miscelle deals with the quotations from the gospels in the Syriac version of Theodore of Mopsuestia's catechetical homilies. Many of these quotations correspond with Syriac gospel texts that are earlier than Peshitta. In one passage of Homily 14 a mixed quotation from the gospels could also be infl uenced by the old Gospel Harmony “Diatessaron”.
Tätersysteme: Spuren und Strukturen
Authors: Lampe Ernst-Joachim
Published: March 2008

I. Täternormen und Täterlehren

1. Das deutsche Strafgesetzbuch gibt auf die für alle Tätersysteme grundlegende Frage „Wer ist Täter?“ keine systematisch befriedigende Antwort. Aus § 25 Abs. 1, 1. Alt. („Als Täter wird bestraft, wer die Straftat selbst … begeht.“) lässt sich entnehmen, dass das Gesetz Beherrschung bzw. Beherrschbarkeit, also Autonomie des eigenen Wollens und Handelns voraussetzt und dass ihm die Auffassung zugrunde liegt, nur eine solche Autonomie könne die Verantwortung „als Täter“ begründen. Wird Y von X gestoßen und verletzt er taumelnd den Z, dann ist nicht Y, sondern X Täter, weil mangels Autonomie des Y nur X „selbst“ handelt. Gleichwohl handelt X nicht etwa gemäß Abs. 1, 2. Alt. „durch einen anderen“. Denn die systematische Zusammenfassung beider Alternativen in einem Absatz lässt zwar vermuten, dass der Gesetzgeber mit der 2. ebenso wie mit der 1. Alt. einen Fall der Alleintäterschaft hat regeln wollen; trotzdem ergibt der historische Hintergrund, dem die 2. Alt. ihr Dasein verdankt, dass der andere, „durch“ den die Tat begangen wird, seinerseits soweit handlungsfähig sein muss, dass er sich nicht gleich einer Sache gebrauchen lässt. Allerdings bestand ursprünglich die Meinung, dass der andere auch nicht soweit willensfähig sein dürfe, dass er ebenfalls „als Täter“ in Anspruch genommen werden kann. Neuerdings jedoch erkennt die herrschende Lehre für Ausnahmefälle an, dass nicht nur ein in der Autonomie seines Wollens beschränktes menschliches „Werkzeug“, sondern auch ein vollverantwortlich handelnder Täter die Tatverantwortung an den Hintermann vermitteln kann. Lediglich eine Mindermeinung wahrt die Systemreinheit des § 25 Abs. 1, indem sie die vertikale („gestufte“) Gemeinsamkeit mehrerer Täter für einen Fall nicht der mittelbaren, sondern der Mittäterschaft hält.
Chirurgie für die Seele? Eine Fallstudie zu Gegenstand und Grenzen der Sittenwidrigkeitsklausel
Authors: Nitschmann Kathrin
Published: March 2008

I. Einleitung

Volenti non fit iniuria. Der traditionell im Umgang mit Persönlichkeitsrechten und insbesondere im Bereich der Körperverletzung auf Verlangen herangezogene Grundsatz der Digesten weist bereits die Richtung im Hinblick auf ein Thema, das hier unter den zugegebenermaßen provokativen Topos „Chirurgie für die Seele“ gestellt wird: das Phänomen der freiwilligen Amputation gesunder Körperglieder auf Wunsch. Es veranlasst wieder einmal der alten diskutierten Frage nach der Dimension, die eine Einwilligung in die Verletzung der körperlichen Unversehrtheit haben kann bzw. darf, nachzugehen. „Darf sich auf seine Autonomie berufen, wer diese radikal beschränken oder ein für alle Mal beenden will?“, so eine der – eher zynischen – Fragen, die in der öffentlichen Diskussion, die auch unter dem Aspekt „Recht auf vorsätzliche Behinderung“ geführt worden ist, aufgetaucht sind. Es geht um die rechtliche Dimension der Selbstbestimmung, die Verfügungsgewalt über den Körper, im moralphilosophischen Sinne aber auch um die Grenze des Ichs, das Selbstbild des Körpers, die neue Vermessung des Menschen. Der im Januar 2007 in die Schlagzeilen geratene Fall des an statischer Enzephalopathie erkrankten Mädchens Ashley in den USA, das auf Wunsch seiner Eltern unter anderem durch Hormonbehandlung an seiner körperlichen Entwicklung gehindert wird – in diesem Zusammenhang ist auch von vorsätzlicher „Verkrüppelung“ die Rede –, vermag der Debatte noch eine zusätzliche Dimension zu verleihen.
Zurück zur gesetzlichen Beweistheorie? Beobachtungen zu den Legitimationsanforderungen an ein künftiges Abspracheverfahren
Authors: Meyer Frank
Published: March 2008

I. Einleitung

Die Absprache im Strafverfahren ist weder gesetzlich geregelt noch jemals richterrechtlich als zulässiges prozessuales Institut anerkannt worden. Dennoch hat sie der grundsätzlich vergleichsfeindlichen Ausgestaltung des deutschen Strafprozessrechts zum Trotz Eingang in die Rechtswirklichkeit deutscher Strafverfahren gefunden und gehört heute zum festen Bestand prozessualer Instrumentarien. Diese Entwicklung wird gemeinhin als irreversibel angesehen. Man nimmt die Realitäten – teils ernüchtert und ermattet – zur Kenntnis und widmet sich der Hegung der Absprache statt ihrer Bekämpfung. Diese Aufgabe fiel zunächst der Revisionsrechtsprechung zu. Die Grundsatzentscheidung BGHSt. 43, 195 darf als Höhepunkt der Bemühungen gelten, verfahrensbeendende Verständigungen mit den Prinzipien des reformierten Strafprozesses in Einklang zu bringen. Vergleichbare intellektuelle Kraft hat der Gesetzgeber lange Zeit nicht aufgebracht. Das sog. „Eckpunktepapier“ des Bundesjustizministeriums von 2001 sowie der spätere Diskussionsentwurf waren Scheinlösungen. Man wollte vor den Realitäten kapitulieren und die Faktizität der Absprachen lediglich in ein spiegelbildliches positiv-rechtliches Gewand hüllen. Mit dem rechtspolitischen Appell des Großen Senats an den Gesetzgeber aus dem Jahr 2005, die Zulässigkeit und, bejahendenfalls, die wesentlichen rechtlichen Voraussetzungen und Begrenzungen von Urteilsabsprachen gesetzlich zu regeln, ist jedoch Bewegung und Tiefe in die Debatte gekommen. Eine beachtliche Fülle von Vorschlägen, die auch prozessdogmatische Kernfragen nicht mehr aussparen, ist im Anschluss an die Senatsentscheidung formuliert worden. Dieser Beitrag widmet sich zunächst der gewählten Legitimationsgrundlage und dem Rationalitätsverständnis, auf denen die Vorschläge basieren. Vor diesem Hintergrund werden die Reformansätze sodann auf ihre Vereinbarkeit mit den verfassungsrechtlichen und rechtskulturellen Legitimationsanforderungen an ein Abspracheverfahren getestet, die im Schlussteil gerade vor dem Hintergrund der Interdependenzen zwischen den einzelnen Verfahrensabschnitten sowie dem materiellen Strafrecht verdeutlicht werden. Dieser Beitrag darf insofern auch als ein weiteres Plädoyer für ein ganzheitliches Systemverständnis verstanden werden.
Das Opfer vor dem Internationalen Strafgerichtshof
Authors: Bock Stefanie
Published: March 2008

I. Einleitung

Bereits die Präambel des Rom Statuts räumt den Opfern „unvorstellbarer Gräueltaten“ eine herausragende Stellung ein. Damit reiht sich das Rom Statut in eine internationale Bewegung ein, die das Opfer nicht mehr ausschließlich als Mittel zur Informationsbeschaffung, als Zeugen, ansieht. Vielmehr wird dem Opfer zunehmend die Möglichkeit gewährt, aktiv auf das Prozessgeschehen Einfluss zu nehmen. Die Vertreter der Justiz sollen den Interessen des Opfers Rechnung tragen und dieses vor prozessimmanenten Belastungen schützen. Vorläufiger Höhepunkt dieser Entwicklung ist zumindest aus europäischer Sicht die Entscheidung des EuGH vom 16.6.2005 zur Auslegung des Rahmenbeschlusses über die Stellung des Opfers im Strafverfahren. Vor diesem Hintergrund sollen die opferbezogenen Verfahrensvorschriften des IStGH unter Berücksichtigung viktimologischer Erkenntnisse dargestellt werden.
Die Reform des türkischen Strafrechts
Authors: Sözüer Adem
Published: March 2008

I. Einführung

In der Türkei wurde am 26. September 2004 ein neues Strafgesetzbuch verabschiedet, das am 1. Juni 2005 in Kraft getreten ist. Es löste das alte Strafgesetzbuch von 1926 ab, das auf dem italienischen Strafgesetzbuch „Codice Zanardelli“ von 1889 beruhte. Von Beginn an litt das erste StGB der türkischen Republik unter vielen Schwächen. Es reflektierte vor allem die Strafrechtsideen des 19. Jahrhunderts, deren Strafrechtstheorie sich entscheidend auf die Kausalität stützte. Dieses StGB wurde über 70 Mal seit seinem Inkrafttreten geändert; es verlor dabei seine logische Struktur und systematische Einheitlichkeit. Darüber hinaus wurden Regelungen in das Gesetz aufgenommen, die mit den allgemeinen Grundsätzen der Strafrechtstheorie und der Deliktslehre unvereinbar waren. Zudem gab es Widersprüche zwischen dem Kernstrafgesetzbuch und den Nebenstrafgesetzen. In jahrelangen Vorarbeiten einer Kommission aus Wissenschaftlern und Praktikern entstanden in den Jahren 1987, 1989, 1997, 2000 und 2003 Entwürfe, die alle als zu konservativ angesehen wurden und im übrigen dem Konzept des alten StGB im Kern treu blieben. Basierend auf dem Entwurf von 2003 brachte die türkische Regierung schließlich einen Entwurf ins Parlament ein, der allerdings weiterhin heftiger Kritik ausgesetzt war, die in erster Linie aus der Regierungspartei AKP selbst kam. Ferner schlugen akademische Berater, die dem Unterausschuss des Rechtsausschusses „Reform des türkischen Strafgesetzbuchs“ zur Seite standen, aus wissenschaftlicher Sicht umfassende Änderungen vor. Außerdem wollte die türkische Regierung das neue StGB als eines der Kernstücke ihrer Reformarbeit vor dem Hintergrund der Empfehlung der Europäischen Kommission über die Aufnahme der Beitrittsverhandlungen der Europäischen Union mit der Türkei am 6. Oktober 2004 präsentieren. Daher wurde im Unterausschuss des Rechtsausschusses ein fast vollständig neuer Entwurf vorbereitet, der kurze Zeit später mit einigen Änderungen und Ergänzungen vom Parlament mit großer Mehrheit verabschiedet wurde.
Crack path in an amorphous material in the quasi static limit
Authors: Thomson Robb
Published: March 2008

Crack path stability is discussed, and it is shown that the standard continuum mechanics-force on a crack is the correct driving force for a crack. In a glass, where all cleavage planes are possible, this criterion also implies a path where the local Mode II on the crack is nullified.
Study of enhanced phosphorus activity inn-type Si80Ge20as a function of the doping process
Authors: Han S. H. , Cook B. A.
Published: March 2008

The electrical activity of phosphorus in Si80Ge20alloys prepared by two nonconventional doping processes has been investigated over the temperature range 25–1250 °C. Both a solid state (mechanical alloying) and gaseous phase doping processes were found to extend the electrical activity of phosphorus in Si80Ge20alloys beyond the reported maximum equilibrium value (2.1 × 1020/cm3) to 2.5–2.9 × 1020/cm3within the temperature range 900 1200 °C. It is likely that this extended electrical activity of phosphorous is associated with a high density of defects. The enhanced electrical activity of phosphorus enabled Si80Ge20alloys to have 300 to 1000 °C integrated average electrical power factors in the range 30.1–35.7 μW/cm-°C2.
The infrared dielectric properties of η–Al2O3
Authors: Pecharromán Carlos , González-Carreño T. , Iglesias Juan E.
Published: March 2008

The infrared complex permittivity function of pseudo-cubic, disordered, spinel-type variety of alumina, η–Al2O3, obtained by spray pyrolysis, has been determined from its IR reflectance spectra, measured at near to normal incidence on pressed powder pellets. The optical constants obtained therefrom have been verified by using them in the simulation of the corresponding absorption spectra for KBr-diluted pellets of this material, and these are in excellent agreement with the experimental spectra. All calculations are based on a procedure for the estimation of the effective dielectric function of a mixture incorporating percolation features, which has been recently developed by the authors.
Interface structure of a YBa2Cu3O7−x/N/YBa2Cu3O7−x superconductor/normal metal/superconductor Josephson junction using YBa2Cu2.79Co0.21O7−x as the normal barrier N
Authors: Rozeveld S. , Merkle K. L. , Char K.
Published: March 2008

Superconductor-normal-superconductor (SNS) edge junctions consisting of YBa2Cu3O7/YBa2Cu2.79Co0.21O7−x/YBa2Cu3O7 were fabricated on (001) YSZ substrates using laser deposition. In contrast to other SNS junctions, e.g., with La0.5Sr0.5CoO3, CaRuO3, or SrRuO3 as the barrier layer, these devices do not display an excess normal-state resistance. High-resolution and conventional transmission electron microscopy (TEM) techniques were employed to investigate the SN interface structure and possible interface defects. Results are compared to recent TEM investigations of CaRuO3 SNS junctions.
Numerical calculation of the crystal rotation effect on YBa2Cu3O7−x single crystal growth by the pulling method
Authors: Namikawa Y. , Egami M. , Shiohara Y.
Published: March 2008

A series of numerical calculations of convection were performed for the YBa2Cu3O7−x (Y123) single crystal growth by the modified pulling method (Solute Rich Liquid Crystal Pulling method; SRL-CP method). The finite-difference method was used to calculate the steady state of the axisymmetric two-dimensional incompressible viscous fluid system. The effect of the crystal rotation on the flow pattern and the temperature distribution in the melt was studied. An increase of the crystal diameter and/or the crystal rotation rate increased the strength of the forced convection in the melt, and as a result, the temperature at the crystal growth interface increased. These results were consistent with the experimental results.
Surface and optical properties of porous silicon
Authors: Prokes S. M.
Published: March 2008

Although silicon is the material of choice in the semiconductor industry, it has one serious disadvantage: it is an extremely poor optoelectronic material. This is because it is an indirect gap semiconductor, in which radiative transition results in extremely weak light emission in the infrared part of the spectrum. Thus, the discovery of strong visible luminescence from a silicon-based material (porous silicon) has been quite surprising and has generated significant interest, both scientific and technological. This material differs from bulk silicon in one important way, in that it consists of interconnected silicon nanostructures with very large surface to volume ratios. Although the first mechanism proposed to explain this emission process involved carrier recombination within quantum size silicon particles, more recent work has shown that the surface chemistry appears to be the controlling factor in this light emission process. Thus, the aim of this work is to outline the data and arguments that have been presented to support the quantum confinement model, along with the shortcomings of such a model, and to examine more recent models in which the chemical and structural properties of the surface regions of the nanostructures have been incorporated.
Characterization of InGaAsP materials by ultrahigh intensity post-ionization mass spectrometry: Relative sensitivity factors for zinc versus bulk constituents
Authors: Wise M. L. , Downey S. W. , Emerson A. B.
Published: March 2008

The first relative sensitivity factors (RSF) for detecting the major and dopant elements of optical materials by ultrahigh intensity post-ionization (UHIPI) mass spectrometry are determined. The post-ionization is performed using a single laser wavelength with intensities greater than 1014 W/cm2. Zn-implanted InP and In0.4Ga0.1As0.3P0.2 are used to investigate the photoionization of sputtered atoms and molecules. Under optimal conditions, the UHIPI RSF's for atomic singly charged In, Ga, and Zn are nearly equal; that is, the ratio of UHIPI signals is equal to the concentration ratio. In principle, no standards are needed for quantitative analysis. Arsenic and P, with higher ionization potentials, are not detected as efficiently as other elements. The detected mass balance is usually group III rich. An entire mass spectrum is necessary for complete characterization of all elements and adjustment of their RSF's because many sputtered molecules are detected containing the group V elements. Multiply charged species compose about 10% of the detected ions.
X-ray diffraction and x-ray photoelectron spectroscopy study of the Ru–Cu/SiO2 system prepared by low temperature reduction: Occurrence of a metastable amorphous or nanocrystalline phase
Authors: Lenarda Maurizio , Ganzerla Renzo , Storaro Loretta , Frattini Romana , Enzo Stefano , Zanoni Roberto
Published: March 2008

Bimetallic copper-ruthenium catalysts supported on silica were prepared by the reduction of the metallic salts in aqueous solution at room temperature. The concentration of the two metal components was selected to span the entire range of composition. In spite of the known immiscibility for the copper-ruthenium equilibrium phase diagram, X-Ray Diffraction (XRD) measurements combined with X-ray Photoelectron Spectroscopy (XPS) data indicate that this method of preparation is able to produce nanocrystalline extended solid solutions and/or amorphous metastable phases. In the case of ruthenium-rich compositions, the hexagonal close-packed (hcp) ruthenium crystallites are covered by copper atoms which grow with the same hcp sequence of the ruthenium core. For intermediate compositions a nanocrystalline and/or amorphous phase is observed, while in the case of copper-rich samples a single-phase fcc extended solid solution is found. The surface composition of the samples appears systematically enriched with Cu, as obtained from XPS semiquantitative results. The phenomena of phase separation and growth induced by thermal annealing at 870 K are also presented and discussed.
Sintering kinetics of silica-titania sol-gel films on silicon wafers
Authors: Du Xin Min , Almeida Rui M.
Published: March 2008

The sintering behavior of 80SiO2–20TiO2 sol-gel thin films on Si wafers, prepared by spin coating, was studied by the calculation of density as a function of temperature, from refractive index measurements and the Lorenz–Lorentz relationship. The sintering kinetics of the films were fit to the Mackenzie and Shuttleworth model, over the temperature range of 700 °C–850 °C. Using this model, the viscosity was determined as a function of temperature. These gel films sintered to full density at 850 °C.
Artificial dielectrics of conductive fibers in polymers: Effects of viscosity and matrix composition on permittivity and loss
Authors: Ho Yung-Shou , Schoen P.
Published: March 2008

We report the microwave dielectric properties of composites made of nickel-coated graphite fibers in two different types of silicone polymers. The influence of matrix viscosity on the fiber alignment, fiber filamentation in the composites, and how those affect the permittivity and loss tangent of the composite are discussed. The dependence of the permittivity and loss of the composites on the permittivity and loss of the matrix will also be compared.
Synthesis of α–Fe2O3 particle/oligomer hybrid material
Authors: Yogo Toshinobu , Nakamura Tomoyuki , Kikuta Ko-ichi , Sakamoto Wataru , Hirano Shin-ichi
Published: March 2008

A nanocrystalline α–Fe2O3 particle/oligomer hybrid can be synthesized by polymerization of iron (III) 3-allylacetylacetonate (IAA) followed by in situ hydrolysis. The polymerization of IAA was dependent upon the polymerization temperature and solvent. GPC measurement showed that the polymerization degree of the IAA oligomer ranged from ∼3 to ∼6. The magnetic particle/oligomer hybrid was synthesized by hydrolysis of the IAA oligomer under a neutral or alkaline condition. Crystalline particles from 10 to 40 nm were finely dispersed in the oligomeric matrix, depending upon the hydrolysis conditions. The nanocrystalline particles below 10 nm in diameter were identified to be α−Fe2O3 by electron diffraction. The nanosized α−Fe2O3/oligomer hybrid was found to show superparamagnetic behavior.
The dynamic compressive behavior of beryllium bearing bulk metallic glasses
Authors: Bruck H. A. , Rosakis A. J. , Johnson W. L.
Published: March 2008

In 1993, a new beryllium bearing bulk metallic glass with the nominal composition Zr41.25Ti13.75Cu12.5Ni10Be22.5 was discovered at Caltech. This metallic glass can be cast as cylindrical rods as large as 16 mm in diameter, which permitted specimens to be fabricated with geometries suitable for dynamic testing. For the first time, the dynamic compressive yield behavior of a metallic glass was characterized at strain rates of 102 to 104/s by using the split Hopkinson pressure bar. A high-speed infrared thermal detector was also used to determine if adiabatic heating occurred during dynamic deformation of the metallic glass. From these tests it appears that the yield stress of the metallic glass is insensitive to strain rate and no adiabatic heating occurs before yielding.
How to tailor the porous structure of alumina and aluminosilicate gels and glasses
Authors: Vendange V. , Colomban Ph.
Published: March 2008

Optically clear monolithic (OCM) gels of mesoporous aluminosilicates (average pore diameter 3.6 nm) and alumina (6 nm) have been prepared by slow hydrolysis-polycondensation of alkoxides and converted into OCM mesoporous glasses by heating. In order to change the properties, different ways of modifying the pore size and structure are proposed. We show that addition of boron oxide reduces the average pore diameter. A higher effect can be obtained by addition of a surfactant. In this case the mesoporous matrix becomes microporous (d < 2 nm). Another way of modifying the pore structure consists of introducing nanoprecipitates inside the porosity by an impregnation process. Modifications of the porous structure are different in alumina and aluminosilicates.
Formation of BaTiO3 and PbTiO3 thin films under mild hydrothermal conditions
Authors: Xu W-ping , Zheng Lirong , Xin Huoping , Lin Chenglu , Okuyama Masanori
Published: March 2008

Well-crystallized polycrystalline thin films of cubic barium titanate (BaTiO3) have been synthesized on Ti-covered Si substrates by exposing the substrates to a Ba(OH)2 aqueous solution at 160 °C and a low pressure less than 1 MPa. It was presumed that the film formation of BaTiO3 involved a dissolution-crystallization mechanism, which provides an attractive approach to produce other titanate films and powders. Also, we have used for the first time this hydrothermal technique to deposit epitaxial (001)-textured PbTiO3 thin films on SrTiO3(100) substrates.
Modeling the effect of gas transport on the formation of defects during thermolysis of powder moldings
Authors: Song J. H. , Edirisinghe M. J. , Evans J. R. G. , Twizell E. H.
Published: March 2008

The removal of binder from ceramic or metal moldings by thermolysis involves the transport of degradation products through the parent organic phase and the vacated porous body. A numerical model has been developed to combine an equation which takes into account different gas-flow regimes with an equation for the transport of organic molecules in molten polymers. Computer modeling reveals the critical heating rate above which defects occur due to boiling of the polymer-monomer solution at the center of the molding. The situation in which a porous outer layer of the molding develops, offering resistance to flow of the evolved monomer gas, is then treated. This gives rise to a moving boundary with a variable concentration of diffusant which is dependent on the surface flux, gas transport coefficient, and thickness of the porous layer. The contributions of diffusion and viscous flow to gas transport are considered.
A mechanism for reactive diffusion between Si single crystal and NbC powder compact
Authors: Kao C. R. , Woodford J. , Chang Y. A.
Published: March 2008

Based on our recent experimental observations, a growth mechanism for the reactive diffusion between Si single crystal and NbC powder compact is proposed. In Si–NbC diffusion couples annealed at 1300 °C, a two-phase NbSi2 + SiC reaction layer formed with NbSi2 as the matrix and SiC as discontinuous particles. The NbSi2 grain sizes and SiC particle sizes are both in the μm range. We propose that the SiC particles nucleated at the void surfaces in the NbC powder compact. This proposed nucleation mechanism offers a potential way of controlling the SiC particle size by changing the void size and void density of the NbC powder compact. It is also pointed out that this microstructure requires Si to be the dominant diffusing species. Si must diffuse through the reaction layer, while C only has to undergo local rearrangement, and Nb need not diffuse at all.
Effect of palladium on the hydrogen embrittlement of B-doped Ni3Al
Authors: Yang Liu , McLellan Rex B.
Published: March 2008

A discussion of the embrittlement of B-doped and B-free Ni3Al is given. Tensile test data and SEM fractography have been evaluated to show that additions of Pd to polycrystalline Ni3Al (B) essentially eliminate the embrittlement concomitant to charging Ni3Al (B) to the level of ∼5 wt. ppm of hydrogen.
Porous Ca–P–O bio-glassceramics by loose-powder-sintering
Authors: Chin T. S. , Wu D. C. , Hung M. P. , Wang C. P.
Published: March 2008

Porous resorbable Ca–P–O glassceramic tooth roots based on calcium biphosphate were prepared by loose-powder-sintering then crystallization-annealing. The glass composition is, by weight, CaO/(CaO + P2O5) = 0.33. The sintering behavior of the glass can be described by a conventional viscous flow model. The resultant glassceramic has a pore size of 6 to 36 μm, depending on starting particle size and sintering temperature, while the pore size distribution is independent of sintering time. The flexural strength is 33 to 150 MPa depending mostly on crystallization-annealing treatment. The crystalline phases are β−Ca2P2O7 and CaP2O6. After being implanted into rabbits, these porous implants show remarkable biocompatibility and induce the ingrowth of new bone within 30 days. They are partly resorbed after 90 days and replaced by new bone. In spite of the original small porosity, the ingrowth of blood vessels and bone cells is abundantly seen after 90 days, due to enlarged pores produced by progressive resorption. This glassceramic is a good candidate for resorbable tooth and bone implants. The loose-powder-sintering technique resulting in intricate bulk shapes with controllable pore size distribution and good machinability as well as adjustable mechanical strength hence is a powerful technique for the preparation of porous glassceramics.
Praseodymium and high-temperature superconductivity: Thermodynamic, structural, and critical correlations
Authors: Lamberti V. E. , Rodriguez M. A. , Trybulski J. D. , Navrotsky A.
Published: March 2008

The enthalpies of formation and the partial molar enthalpies of oxidation of polycrystalline LnBa2Cu3Oy (Ln = Pr, Nd, Eu, Gd, Dy, Ho, Tm) and Y1−xPrxBa2Cu3Oy (x = 0.0, 0.1, 0.2, 0.5, 0.8, 0.9, 1.0) have been determined at 298 K by drop-solution calorimetry. The thermodynamic characteristics of Pr123 follow the trends of the trivalent-ion-based Ln123 compounds. The thermodynamic data for the (Y,Pr)123 solid solutions show nonideal solution behavior, but no x-dependent valence instability. The superconducting critical temperatures and the enthalpies of oxidation of the (Y,Pr)123 solid solutions are linearly related.
Fabrication and characteristics of weak links between â- and ĉ-axis normal grains of Y1Ba2Cu3O7−x
Authors: Mahajan S. , Buchholz D. B. , Lei J. , Chang R. P. H. , Hogan T. , Kannewurf C. R. , Song S. N. , Ketterson J. B. , Hinds B. , Marks T. J. , Eckstein J.
Published: March 2008

We have used pulsed organometallic beam epitaxy (POMBE) to simultaneously deposit â- and ĉ-axis oriented Y1Ba2Cu3O7−x (YBCO) thin films at arbitrary locations on LaAlO3(100) substrates. Using photolithography and ion milling, several types of â-ĉ weak links have been fabricated at the boundary between the two films. The current-voltage (I-V) characteristics show a flux flow type behavior. The resistive transitions are broad and the critical current density is low, indicating weak coupling across these boundaries. With magnetic field applied parallel to the grain boundary plane, nonhysteretic I-V curves are obtained and the critical current goes to zero at an applied magnetic field of ∼7500 G.
Biaxial alignment of high-Tc superconductor polycrystals VIII: Phi-circle scan analysis of EuBa2Cu3O7−δ (Eu-123)
Authors: Wang Sheng-Qi , Bigelow Roberta A. , Zhang Jian-Zhong , Bonetto Carlos , Maheswaran Bala , Markiewicz Robert S. , Williams Mary G. , Giessen Bill C.
Published: March 2008

To reduce grain boundary weak links due to large-angle grain orientation mismatch, bulk (thick film) EuBa2Cu3O7−δ high-Tc superconductor specimens were biaxially aligned by a mechanical force such that their [001] axes were perpendicular to the specimen surfaces and by a magnetic force so as to orient their [010] axes to lie parallel to the magnetic field direction in the specimen plane. We describe here the characterization of such EuBa2Cu3O7−δ thick films by φ-circle XRD scans of (013) reflections, demonstrating a high degree (33%) of c-axis alignment with FWHM of <5° and approximately Gaussian distributions of a, b-axis alignment with a FWHM of 47°. The formation of “granular single crystals”, toward which this work is a further advance, can be seen as establishing a new paradigm in ceramics science.
Synthesis, characterization, and properties of lead-based relaxor ferroelectrics
Authors: Sekar Michael M. A. , Halliyal Arvind , Patil K. C.
Published: March 2008

Lead-based relaxor ferroelectrics such as Pb(Mg1/3Nb2/3)O3 (PMN), Pb(Zn1/3Nb2/3)O3 (PZN), and their solid solutions with BaTiO3 and PbTiO3 have been prepared by a solution combustion process which involves metal nitrates/oxalate and tetraformal trisazine (TFTA) at 350 °C. Thermal evolution of perovskite relaxors has been investigated at different temperatures of calcination using the powder x-ray diffraction method. Particles are fine and sinter-active at low temperature (1050 °C). Both particulate and dielectric properties are compared.
Mechanisms of Al and titania hydrogel complex formation via a mechanical route
Authors: Kojima Yuumi , Isobe Tetsuhiko , Senna Mamoru , Shinohara Takeshi , Ono Sakai , Sumiyama Kenji , Suzuki Kenji
Published: March 2008

The process of complex formation has been studied during milling a powder mixture of metallic Al and titania hydrogel, TiO2 · H2O. Solid state 27Al NMR and ESR are employed together with conventional x-ray diffractometry and thermal analyses. Al atoms partly changed from metallic to oxide state. 27Al NMR analyses indicate that two metallic Al states are allotted to distorted and undistorted lattices, while the other to AlOx units in the oxide state, where x is 4, 5, or 6. As detected by ESR, Ti4+ was partly reduced to Ti31, suggesting a redox reaction during milling. A vigorous thermit reaction was detected during subsequent heating of the mixture after prolonged milling. These results indicate the formation of Al–O–Ti bonds during milling, leading to Al2TiO5 on subsequent heating.
High-temperature plasticity of cubic bismuth oxide
Authors: Vilette Anne , Kampe S. L.
Published: March 2008

Cubic (δ) bismuth oxide (Bi2O3) has been subjected to high temperature deformation over a wide range of temperatures and strain rates. Results indicate that bismuth oxide is essentially incapable of plastic deformation at temperatures below the monoclithic to cubic phase transformation which occurs at approximately 730 °C. Above the transformation temperature, however, Bi2O3 is extensively deformable. The variability of flow stress to temperature and strain rate has been quantified through the determination of phenomenological-based constitutive equations to describe its behavior at these high temperatures. Analysis of the so-determined deformation constants indicate an extremely strong sensitivity to strain rate and temperature, with values of the strain-rate sensitivity approaching values commonly cited as indicative of superplastic behavior.
The effects of particle size distribution and induced unpinning during grain growth
Authors: Thompson G. S. , Rickman J. M. , Harmer M. P. , Holm E. A.
Published: March 2008

The effect of a second-phase particle size distribution on grain boundary pinning was studied using a Monte Carlo simulation technique. Simulations were run using a constant number density of both whisker and rhombohedral particles, and the effect of size distribution was studied by varying the standard deviation of the distribution around a constant mean particle size. The results of present simulations indicate that, in accordance with the stereological assumption of the topological pinning model, changes in distribution width had no effect on the pinned grain size. The effect of induced unpinning of particles on microstructure was also studied. In contrast to predictions of the topological pinning model, a power law dependence of pinned grain size on particle size was observed at T = 0.0. Based on this, a systematic deviation to the stereological predictions of the topological pinning model is observed. The results of simulations at higher temperatures indicate an increasing power law dependence of pinned grain size on particle size, with the slopes of the power law dependencies fitting an Arrhenius relation. The effect of induced unpinning of particles was also studied in order to obtain a correlation between particle/boundary concentration and equilibrium grain size. The results of simulations containing a constant number density of monosized rhombohedral particles suggest a strong power law correlation between the two parameters.
Plasma treatment of polyaniline films: Effect on the intrinsic oxidation states
Authors: Kang E. T. , Kato K. , Uyama Y. , Ikada Y.
Published: March 2008

Surface modification of emeraldine (EM) and nigraniline (NA) base films by argon plasma treatment was investigated by x-ray photoelectron spectroscopy (XPS). Argon plasma treatment, followed by atmospheric exposure, results in the oxidation of some carbon atoms, first to C–O species and then to C = O and COOH species for samples with extended plasma treatment time. Most important of all, Ar plasma treatment and the accompanied carbon oxidation readily cause a decrease in the intrinsic oxidation state ([=N— ]/[—NH—] ratio) of the aniline polymers.
Ball-milling of Fe–Zn intermetallics
Authors: Liu Z. T. , Uwakweh O. N. C.
Published: March 2008

The ball-milling of pure Fe and Zn elemental powders corresponding to the Г-(Fe3Zn10), Г1-(Fe5Zn21), δ-(FeZn7), and ζ-(FeZn13) compositions yields metastable crystalline phases. This is demonstrated by the peaks observed in the DSC measurements of the different phases. These crystalline phases evolve differently with distinct or characteristic stages with heat treatments. Cold-welding and powder agglomeration are extensive, while the milled materials are completely homogeneous.
A quantitative analysis of cavitation in Al–Cu–Mg metal matrix composites exhibiting high strain rate superplasticity
Authors: Wada Shuichi , Mabuchi Mamoru , Higashi Kenji , Langdon Terence G.
Published: March 2008

Specimens of two Al–Cu–Mg (2124) composites, reinforced with 20 vol% of either Si3N4 particulates or Si3N4 whiskers, were tested under experimental conditions close to those for optimum high strain rate superplasticity. Both composites developed extensive internal cavitation during testing, but quantitative measurements show that significant cavity growth occurs throughout the test in the whisker-reinforced composite, but only at strains ≥1.0 in the particulate-reinforced composite. This difference in behavior is attributed to differences in the extent of a discontinuous liquid phase at the grain boundaries and at the matrix/reinforcement interfaces. It is concluded that the presence of an extensive liquid phase in the particulate-reinforced composite is beneficial for attaining high ductility because it relieves the stress concentrations from grain boundary sliding and thereby limits the growth of cavities.
Comparative measurement of residual stress in diamond coatings by low-incident-beam-angle-diffraction and micro-Raman spectroscopy
Authors: Mohrbacher H. , Acker K. Van , Blanpain B. , Houtte P. Van , Celis J-P.
Published: March 2008

Two experimental techniques for the quantitative measurement of residual stress in thin polycrystalline diamond coatings have been developed. The x-ray low-incident-beam-angle-diffraction (LIBAD) allows one to measure the lattice strain with well-defined in-depth information, while micro-Raman spectroscopy permits one to accurately measure the frequencies of the zone-center optical phonons of diamond which are related to the lattice strain. The interpretation of the measured information in terms of residual stress is outlined for both techniques. The residual stress data obtained by either method in thin CVD diamond coatings were found to be in excellent agreement. The sign and magnitude of the balanced biaxial stress in the coating plane depend mainly on the substrate material used for the diamond deposition. Compressive stress was present in diamond coatings deposited on WC-Co substrates, whereas tensile stress was found in those on SiAlON substrates.
Simultaneous combustion synthesis and consolidation of intermetallics MoSi2
Authors: Subrahmanyam J. , Mohan Rao R. , Subba Rao S. , Somaraju K.
Published: March 2008

A novel technique has been developed for simultaneous combustion synthesis and consolidation of intermetallics in a single step from elemental powders. The method has been applied for the synthesis and consolidation of MoSi2. A temperature profile of the combusted compact provides the temperature-time regime for consolidation. The products were characterized for density, phase formation, and microstructure.
An investigation of grain boundaries in submicrometer-grained Al-Mg solid solution alloys using high-resolution electron microscopy
Authors: Horita Zenji , Smith David J. , Furukawa Minoru , Nemoto Minoru , Valiev Ruslan Z. , Langdon Terence G.
Published: March 2008

High-resolution electron microscopy was used to examine the structural features of grain boundaries in Al–1.5% Mg and Al–3% Mg solid solution alloys produced with submicrometer grain sizes using an intense plastic straining technique. The grain boundaries were mostly curved or wavy along their length, and some portions were corrugated with regular or irregular arrangements of facets and steps. During exposure to high-energy electrons, grain boundary migration occurred to reduce the number of facets and thus to reduce the total boundary energy. The observed features demonstrate conclusively that the grain boundaries in these submicrometer-grained materials are in a high-energy nonequilibrium configuration.
The spreading kinetics of Ag–28Cu(L)on nickel(S): Part I. Area of spread tests on nickel foil
Authors: Weirauch Douglas A. , Krafick William J.
Published: March 2008

Dynamic hot-stage microscopy and sessile drop experiments have identified three stages in the spreading of Ag–28 wt. % Cu liquid on the surface of high-purity Ni foil: (I) nonreactive flow, (II) secondary spreading, and (III) breakout flow. The first stage is deGennes-type spreading driven by capillary forces and resisted by viscous drag. A (Cu, Ni) reaction layer forms quickly at temperature along the liquid-solid interface. Stage I ends when the liquid braze attains a quasistatic contact angle on the reacted surface. Stage II spreading involves a complex advance of a thin liquid sheet outward from the triple line as a result of differences in wetting between Ni grain surfaces and grain boundaries. The advancing liquid meniscus is distorted as the liquid moves ahead along the better wetted grain boundary regions and is held back (pinned) on those surfaces that are poorly wet, resulting in a stick-slip motion of the triple line. The change in contact area with time is linear during this stage, and the rate of spreading is independent of temperature in the range of 780–870 °C. Although the diffusion of Cu into Ni grain boundaries likely drives the capillary flow, it is not the controlling process since an activation energy is not observed. The final stage of spreading, breakout flow, involves the flooding of the liquid braze over previously wetted surfaces due to a change in the balance of interfacial energies. Spreading ends during stage II or III either by isothermal solidification which stems from interdiffusion between the braze filler and the substrate or by curtailment of the liquid supply when it pulls back on the (Cu, Ni) reaction layer. Hold time, peak temperature, and heating rate all have an effect on both the terminal area of spread and the spreading kinetics of braze flow on polycrystalline Ni. The heating rate effect has not been emphasized in previously published literature for soldering and brazing and, if overlooked could easily impair one's ability to apply test results to other studies or practical situations. Roughness-enhanced spreading was not observed with the Ni foil surfaces used in this study. There was, however, a localized effect on the shape of the triple line that did not affect spreading kinetics or terminal area of spread in a systematic fashion.
Mathematical modeling of cement paste microstructure by mosaic pattern: Part I. Formulation
Authors: Xi Yunping , Tennis Paul D. , Jennings Hamlin M.
Published: March 2008

This paper develops a mathematical model using mosaic patterns to characterize structural features of complex, multiphase, and multidimensional microstructures, such as those for cement paste. A multiphase microstructure can be characterized by m independent parameters; the first m– 1 parameters are equivalent to the volume fractions of the phases, while the final parameter describes the grain size, and thus, the spatial arrangement of the microstructure. An evaluation procedure for the parameters is given; they can be evaluated based on a 2D image, and then the 3D microstructure can be simulated by the present model. The relationship among the model parameters and material parameters, such as water-to-cement ratio and particle size distribution, are also established.
Kinetic and structural studies of oxygen availability of the mixed oxides Pr1–xMxOy (M = Ce, Zr)
Authors: Sinev M. Yu. , Graham G. W. , Haack L. P. , Shelef M.
Published: March 2008

One composition of Pr–Ce mixed oxide and a range of compositions of Pr–Zr mixed oxide were prepared by coprecipitation methods and characterized by x-ray powder diffraction, thermogravimetric analysis, and x-ray photoelectron spectroscopy. Based on phases formed, the PrOy—ZrO2 system in an oxygen-containing atmosphere at moderate temperatures (up to 800–1000 °C) is analogous to that of CeO2–ZrO2. Addition of either Ce or Zr to pure Pr oxide affects both the total amount of oxygen that can be reversibly exchanged between oxide and gas phase and the kinetics of the redox processes. Ce dramatically increases the amount (per Pr atom) and lowers the temperature of exchange, Zr slightly decreases the amount and also lowers the temperature of exchange, and both modifiers speed up the rate. These observations are rationalized in terms of bulk and surface structural features of the mixed oxides.
High-temperature creep of low-dielectric-constant glass composites
Authors: Jean Jau-Ho
Published: March 2008

The constant-stress compressive creep behavior of a low-dielectric constant (low-k) glass composite, containing a low-softening-point borosilicate glass (BSG) and a high-softening-point high silica glass (HSG), has been investigated at 800–950 °C. For all stages of creep, the deformation behavior exhibits linear viscoelasticity, and is controlled by viscous flow of the low-softening-point borosilicate glass. An analytical expression is proposed to describe mathematically the creep behavior of the glass composite, and the results show a fairly good agreement with experimental observations.
Factors Affecting Articulation Skills in Children with Velocardiofacial Syndrome and Children with Cleft Palate or Velopharyngeal Dysfunction: A Preliminary Report
Authors: Baylis Adriane L. , Munson Benjamin , Moller Karlind T.
Published: March 2008

Objective:

To examine the influence of speech perception, cognition, and implicit phonological learning on articulation skills of children with velocardiofacial syndrome (VCFS) and children with cleft palate or velopharyngeal dysfunction (VPD).

Design:

Cross-sectional group experimental design.

Participants:

Eight children with VCFS and five children with nonsyndromic cleft palate or VPD.

Methods and Measures:

All children participated in a phonetic inventory task, speech perception task, implicit priming nonword repetition task, conversational sample, nonverbal intelligence test, and hearing screening. Speech tasks were scored for percentage of phonemes correctly produced. Group differences and relations among measures were examined using nonparametric statistics.

Results:

Children in the VCFS group demonstrated significantly poorer articulation skills and lower standard scores of nonverbal intelligence compared with the children with cleft palate or VPD. There were no significant group differences in speech perception skills. For the implicit priming task, both groups of children were more accurate in producing primed nonwords than unprimed nonwords. Nonverbal intelligence and severity of velopharyngeal inadequacy for speech were correlated with articulation skills.

Conclusions:

In this study, children with VCFS had poorer articulation skills compared with children with cleft palate or VPD. Articulation difficulties seen in the children with VCFS did not appear to be associated with speech perception skills or the ability to learn new phonological representations. Future research should continue to examine relationships between articulation, cognition, and velopharyngeal dysfunction in a larger sample of children with cleft palate and VCFS.