ALBERT

Notizen: Andalusite porphyroblasts are totally pseudomorphosed by margarite–paragonite aggregates in aluminous pelites containing the peak mineral assemblage andalusite, chlorite, chloritoid, margarite, paragonite, quartz ± garnet, in a NW Iberia contact area. Equilibria at low P–T are investigated using new KFMASH and (mainly) MnCNKFMASH grids constructed with Thermocalc 3.21. P–T and T–X pseudosections with phase modal volume isopleths are constructed for compositions relatively richer and poorer in andalusite to model the assemblages in an andalusite-bearing rock that contains a thin andalusite-rich band (ARB) during retrogression. Their compositions, prior to retrogression, are used in the modelling, and have been retrieved by restoring the pseudomorph-forming elements into the current-depleted matrix, except for Al2O3 which is assumed to be immobile. Compositional differences between the thin band and the rest of the rock have not resulted in differences in andalusite porphyroblast retrogression. The absence of chloritoid resorbtion implies either a pressure increase at constant reacting-system composition, or that its composition changed during retrogression at constant pressure, by becoming enriched in the progressively replaced andalusite porphyroblasts. T–X pseudosections at 1 kbar model this latter process using as end-members in X, first, the restored original rock and ARB compositions, and, then the same process, taking into account the change in composition of both as retrogression proceeded. The MnNCKFMASH pseudosections of rocks with different Al contents facilitate making further deductions on the rock-composition control of the resulting assemblages upon retrogression. Andalusite eventually disappears in relatively Al-poor rocks, resulting, as in this study, in a rock formed by chloritoid–chlorite as the only FM minerals, plus margarite–paragonite pseudomorphs of andalusite. In rocks richer in Al, chlorite would progressively disappear and a kyanite/andalusite–chloritoid assemblage would eventually be stable at retrograde conditions. The Al-silicate, stable during retrogression in Al-rich rocks, indicates pressure conditions and hence the tectonic context under which retrogression took place.

Notizen: In statistically optimised P–T estimation, the contributions to overall uncertainty from different sources are represented by ellipses. One source, for a diffusion-controlled reaction at non-equilibrium, is diffusion modelling of the reaction texture. This modelling is used to estimate ratios, Q, between free-energy differences, ΔG, of reactions among mineral end-members, to replace the equilibrium condition ΔG = 0. The associated uncertainty is compared with those already inherent in the equilibrium case (from end-member data, activity models and mineral compositions). A compact matrix formulation is introduced for activity coefficients, and their partial derivatives governing error propagation. The non-equilibrium example studied is a corona reaction with the assemblage Grt–Opx–Cpx–Pl–Qtz. Two garnet compositions are used, from opposite sides of the corona. In one of them, affected by post-reaction Fe, Mg exchange with pyroxene, the problem of reconstructing the original composition is overcome by direct use of ratios between chemical-potential differences, given by the diffusion modelling. The number of geothermobarometers in the optimisation is limited by near-degeneracies. Their weightings are affected by strong correlations among Q ratios. Uncertainty from diffusion modelling is not large in comparison with other sources. Overall precision is limited mainly by uncertainties in activity models. Hypothetical equilibrium P–T are also estimated for both garnet compositions. By this approach, departure from equilibrium can be measured, with statistical uncertainties. For the example, the result for difference from equilibrium pressure is 1.2 ± 0.7 kbar.

Notizen: This paper characterizes the metamorphic thermal structure of the Higo Metamorphic Complex (HMC) and presents the results of a numerical simulation of a geotherm with melt migration and solidification. Reconstruction of the geological and metamorphic structure shows that the HMC initially had a simple thermal structure where metamorphic temperatures and pressures increased towards apparent lower structural levels. Subsequently, this initial thermal structure has been collapsed by E–W and NNE–SSW trending high-angle faults. Pressure and temperature conditions using the analysis of mineral assemblages and thermobarometry define a metamorphic field P–T array that may be divided into two segments: the array at apparent higher structural levels has a low-dP/dT slope, whereas that at apparent lower structural levels has a high-dP/dT slope. This composite array cannot be explained by heat conduction in subsolidus rocks alone. Migmatite is exposed pervasively at apparent lower structural levels, but large syn-metamorphic plutons are absent at the levels exposed in the HMC. Transport and solidification of melt within migmatite is a potential mechanism to generate the composite array. Thermal modelling of a geotherm with melt migration and solidification shows that the composite thermal structure may be formed by a change of the dominant heat transfer from an advective regime to a conduction regime with decreasing depth. The model also predicts that strata beneath the crossing point will consist of high-grade solid metamorphic rocks and solidified melt products, such as migmatite. This prediction is consistent with the observation that migmatite was associated with the very high-dP/dT slope. The melt migration model is able to generate the very high-dP/dT segment due to the high rate of heat transfer by advection.

Notizen: Sapphirine, coexisting with quartz, is an indicator mineral for ultrahigh-temperature metamorphism in aluminous rock compositions. Here a new activity-composition model for sapphirine is combined with the internally consistent thermodynamic dataset used by THERMOCALC, for calculations primarily in K2O-FeO-MgO-Al2O3-SiO2-H2O (KFMASH). A discrepancy between published experimentally derived FMAS grids and our calculations is understood with reference to H2O. Published FMAS grids effectively represent constant aH2O sections, thereby limiting their detailed use for the interpretation of mineral reaction textures in compositions with differing H2O.For the calculated KFMASH univariant reaction grid, sapphirine + quartz assemblages occur at P–T in excess of 6–7 kbar and 1005 °C. Sapphirine compositions and composition ranges are consistent with natural examples. However, as many univariant equilibria are typically not ‘seen’ by a specific bulk composition, the univariant reaction grid may reveal little about the detailed topology of multi-variant equilibria, and therefore is of limited use for interpreting the P–T evolution of mineral assemblages and reaction sequences. Calculated pseudosections, which quantify bulk composition and multi-variant equilibria, predict experimentally determined KFMASH mineral assemblages with consistent topology, and also indicate that sapphirine stabilizes at increasingly higher pressure and temperature as XMg increases. Although coexisting sapphirine and quartz can occur in relatively iron-rich rocks if the bulk chemistry is sufficiently aluminous, the P–T window of stability shrinks with decreasing XMg. An array of mineral assemblages and mineral reaction sequences from natural sapphirine + quartz and other rocks from Enderby Land, Antarctica, are reproducible with calculated pseudosections. That consistent phase diagram calculations involving sapphirine can be performed allows for a more thorough assessment of the metamorphic evolution of high-temperature granulite facies terranes than was previously possible. The establishment of a a-x model for sapphirine provides the basis for expansion to larger, more geologically realistic chemical systems (e.g. involving Fe3+).

Notizen: Large garnet poikiloblasts hosted by leucosome in metapelitic gneiss from Broken Hill reflect complex mineral–melt relationships. The spatial relationship between the leucosomes and the garnet poikiloblasts implies that the growth of garnet was strongly linked to the production of melt. The apparent difficulty of garnet to nucleate a large number of grains during the prograde breakdown of coexisting biotite and sillimanite led to the spatial focussing of melting reactions around the few garnet nuclei that formed. Continued reaction of biotite and sillimanite required diffusion of elements from where minerals were reacting to sites of garnet growth. This diffusion was driven by chemical potential gradients between garnet-bearing and garnet-absent parts of the rock. As a consequence, melt and peritectic K-feldspar also preferentially formed around the garnet. The diffusion of elements led to the chemical partitioning of the rock within an overall context in which equilibrium may have been approached. Thus, the garnet-bearing leucosomes record in situ melt formation around garnet porphyroblasts rather than centimetre-scale physical melt migration and segregation. The near complete preservation of the high-grade assemblages in the mesosome and leucosome is consistent with substantial melt loss. Interconnected networks between garnet-rich leucosomes provide the most likely pathway for melt migration. Decimetre-scale, coarse-grained, garnet-poor leucosomes may represent areas of melt flux through a large-scale melt transfer network.

Notizen: The paper presents a straightforward method of calculating approximate orientation parameters (six degrees of freedom) of a known targeted object relative to a single calibrated camera. These can then initialise an optimised non-linear calculation of the same parameter values. The method uses the mathematics of a scaled parallel projection and is particularly suited to narrow angle images obtained using a telescope, telephoto or zoom lens. However, the method can also be used with cameras having wider fields of view provided the target group occupies a moderately small part of the image.

Notizen: This paper describes three mathematical modelling methods for high-resolution declassified CORONA KH-4B images. Since CORONA images are collected with a panoramic camera, several types of geometric distortions are involved. Two methods use the modified collinearity equations, and the third involves the terrain-dependent rational function model (RFM) which is considered to be a generic sensor model. Comparative analysis of the three mathematical modelling methods is undertaken. The results show that a ± 1·5 pixels level of horizontal and vertical accuracy can be obtained. A digital elevation model (DEM) of a test site is also created.

Notizen: Professor F. Ackermann was specially invited to contribute an article to mark the 50th issue of The Photogrammetric Record. As the only photogrammetrist to have received both the Brock and von Gruber awards of the International Society for Photogrammetry, he is particularly well qualified to express his views on the past and future development of photogrammetry.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméLe professeur Ackermann a été invitéàécrire un article pour fêter la sortie du 50ème numéro. Seul photogrammètre cumulant médaille de Brock et médaille de von Gruber, il était particulièrement qualifié pour juger du passé et préjuger de l'avenir de la photogrammétrie.〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Professor Ackermann wurde gezielt eingeladen, um einen Beitrag anlässlich des Erscheinens der 50. Ausgabe des Photogrammetric Record beizusteuern. Als einziger Photogrammeter, der sowohl den Brock- als auch v. Gruber-Preis der ISP erhalten hat, ist er besonders qualifiziert, seine Ansichten über Vergangenheit und Zukunft der Photogrammetrie zu äussern.

Notizen: The author describes his experiences of working with Professor E. H. Thompson on the design and construction of the Thompson-Watts plotter and he relates several anecdotes of incidents which took place at the Hilger and Watts factory.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOù on décrit l'expérience d'années passées à travailler avec le professeur Thompson sur le projet du restituteur Thompson- Watts avec de nombreuses anecdotes sur la vie à l'usine Hilger and Watts.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDer Autor schreibt über seine Erfahrungen, die er bei der Zusammenarbeit mit Professor E. H. Thompson beim Entwurf und der Konstruktion des Thompson–Watts-Plotters sammelte. Er erwähnt dabei einige Anekdoten über Vorfälle, die sich bei der Firma Hilger und Watts ereigneten.

Notizen: A history and analysis of stereoplotting instrument design and construction in the United Kingdom is given, beginning with the earliest instruments of F. V. Thompson dating from 1907 and 1908 and covering all known designs up till the late 1960s. In the first part of the paper, the instruments built in the 1920s and 1930s are described, much new information having come to light recently in the archives of Ban and Stroud Ltd. and in the papers of the late Professor E. H. Thompson. In the second part of the paper, the instruments which were produced during and after the Second World War are discussed in detail, with an emphasis on those designs which are less well known rather than those which were produced in quantity. The ideas and designs of Deville, F. V. Thompson, Fourcade and E. H. Thompson have been the dominating influences throughout the period and a strong thread of continuity can be established between them.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn fait l'histoire du restituteur analogique en Grande Bretagne, depuis ses balbutiements (F. V. Thompson 1907–1908), jusq'aux années 60. On décrit en particulier les appareils conçus dans les années 20 et 30, en tenant compte d'une masse d'informations inconnues à ce jour tirées des archives de M. Barr et Stroud, et de celles de feu le professeur Thompson. Puis on passe à ceux qui ont été produits pendant et après la guerre, en s'attachant surtout à ceux qui sont moins connus parce que n'ayant pas été produits en série. Ce sont les idées et projets de Deville, F. V. Thompson, Fourcade et E. H. Thompson qui ont dominé cette période, et le fil qui les relie reste très perceptible.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungEs wird ein Überblick und eine Analyse über den Entwurf und die Konstruktion von Stereoauswertegeräten im Vereinigten Königreich gegeben, wobei der Autor, beginnend mit den ersten Geräten von F. V. Thompson aus den Jahren 1907 und 1908 alle bekannten Entwürfe bis Ende der 60iger Jahre behandelt. Im 1. Teil werden die Geräte der 20iger und 30iger Jahre beschrieben, wobei viel neue Informationen aus dem Archiv der Firma Barr und Stroud und den Beiträgen des verstorbenen Professor E. H. Thompson entstammen. Im 2. Teil werden die während des 2. Weltkrieges und danach produzierten Geräte diskutiert, wobeisolche hervorgehoben werden, die weniger bekannt wurden als die in grossen Stückzahlen produzierten. Die Ideen und Entwürfe von Deville, F. V. Thompson, Fourcade, E. H. Thompson hatten einen bedeutenden Einfluss während dieser Zeit, und es kann eine starke kontinuierliche Verbindung zwischen ihnen aufgezeigt werden.

Notizen: The development of remote sensing techniques for land use studies is briefly reviewed and some problems of interpretation of aerial and satellite photography considered. The need for a ground based data collection system is indicated and a prototype system developed at the University of Bristol is described. Some preliminary results obtained with this system are presented.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn passe en revue les progrès des techniques de télédétection en matière d'étude des sols et on examine certains problèmes d'interprétation des photographies aériennes et satellitaires. On insiste sur la nécessite d'établir une banque de données pour l'interprétation; on décrit le prototype qu'on met au point à l'université de Bristol, et certains résultats qu'il a déjà permis d'obtenir.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDie Entwicklung der Fernerkundungsverfahren für Landnutzungsstudien wird kurz eingeschätzt und einige Probleme der Interpretation von Luftbildern und Satellitenphotos werden analysiert. Dabei wird die Notwendigkeit zur Schaffung eines Datenerfassungssystems im Gelände aufgezeigt und ein Prototyp eines solchen Systems, das an der Universität Bristol entwickelt wurde, beschrieben. Einige hiermit erhaltene vorläufige Ergebnisse werden angegeben.

Notizen: The Photogrammetric Society was formed in 1952. The Council of the Society considered that the twentieth anniversary was a good point at which to record the events which led to its formation and the significant occasions and decisions which have taken place since 1952. Consequently, Paul Lamboit was invited to compile this History. He has placed the birth and development of the Society within the national and international photogrammetric context and his record of the deliberations which took place between 1947 and 1952 will be of particular interest to historians of our subject.This account was first published in a limited edition in 1971. Sufficient interest has since been expressed to prompt a wider circulation through publication in the Photogrammetric Record.The author served the Society continuously in several official capacities from 1953 to 1969 and he was elected to Honorary Membership in 1969.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméLa Photogrammetric Society a été fondée en 1952. Excellente occasion pour faire le point qu'un vingtiéme anniversaire, a estimé le Conseil de la Société; pour rappeler les circonstances de sa naissance, les étapes de sa croissance et les décisions importantes prises depuis 1952. Ce qu'on invita Paul Lamboit à faire. Son exposé resitue la naissance et le développement de la Société dans le contexte national et international de la photogrammétrie; la relation qu'il fait des décisions prises entre 1947 et 1952 intéressera particulièrement ceux qui s'occupent d'histoire de la photogrammétrie.Ce rapport d'abord publié en édition limitée en 1971, a suscité un intérêt suffisant pour que l'on se presse en le publiant dans le Photogrammetric Record de le porter à la connaissance d'un plus large public.L'auteur a exercé différentes fonctions de 1953 à 1969 dans l'appareil de la Société. Il a étéélu membre honoraire en 1969.〈section xml:id="abs1-3"〉〈title type="main"〉Zusummenfussung1952 wurde die Britische Gesellschaft für Photogrammetrie gegründet. Der Rat der Gesellschaft erwog, dass der zwanzigste Jahrestag eine günstige Gelegenheit sei, um die Ereignisse, die zur Gründung der Gesellschaft führten sowie die bedeutenden Veranstaltungen, die stattfanden und die Entscheidungen, die getroffen wurden, darzustellen. Aus diesem Grunde wurde Paul Lamboit eingeladen, diesen historischen Rückblick zu schreiben. Er hat dabei die Gründung und die Entwicklung der Gesellschaft in den nationalen und internationalen photogrammetrischen Zusammenhang gestellt nd sein Bericht über die zwischen 1947 und 1972 erfolgten Beratungen wird für an unserer Sache interessierte Historiker sehr aufschlussreich sein.Diese Zusammenstellung wurde erstmals in einer begrenzten Auflage im Jahre 1971 veröffentlicht. Genügend Interesse wurde inzwischen bekundet, um eine weitergehende Verteilung mit Hilfe des Photogrammetric Record zu veranlassen.Der Autor diente der Gesellschaft kontinuierlich in verschiedenen Ämtern von 1953 bis 1969, wo er aum Ehrenmitglied gewählt wurde.

Notizen: The fourth biennial symposium of the Photogrammetric Society was held at the University of Birmingham on 22nd to 24th April and was dedicated to the memory of the late Professor E. H. Thompson. Nine papers were delivered. The first three were concerned with the life and work of Professor Thompson. Other speakers dealt, in turn, with future instrumentation in photogrammetry; aerial triangulation and film stability; photomaps and tests related to the perception of map users; map revision; and the recording of archaeological information. The majority of the papers are published in this issue of The Photogrammetric Record.〈section xml:id="abs1-2"〉〈title type="main"〉Résumé Le quatrième symposium biannuel de la Photogrammetric Society s'est tenu à l'université de Birmingham du 22 au 24 avril et était dédiéà la mémoire de feu le professeur Thompson. Il y eut neuf exposés, dont les trois premiers portaient sur la vie et l'oeuvre du défunt. D'autres orateurs traitèrent: de l'évolution prévisible des appareillages en photogrammétrie; de l'aérotriangulation et de la stabilité des films; des photoplans et de la manière dont Us sont accueillis par les utilisateurs de cartes; de la révision; et des cartes archéologiques. On trouvera ici la plupart de ces exposés.〈section xml:id="abs1-3"〉〈title type="main"〉ZusammenfassungDas 4. alle zwei Jahre stattfindende Symposium der Britischen Photogrammetrischen Gesellschaft wurde vom 22. bis 24. April an der Universität Birmingham durchgeführt und war dem Gedenken an Professor E. H. Thompson gewidmet. Insgesamt wurden 9 Vorträge gehalten. Die ersten 3 befassten sich mit dem Leben und Wirken von Professor Thompson. Andere Referenten behandelten: künftige photogrammetrische Geräte, Aerotriangulation und Filmstabilität, Kartenergänzung, Bildkarten und Tests über die Auffassung der Kartennutzer, Aufzeichnung archäologischer Informationen. Die Mehrzahl der Beiträge wird im vorliegenden Heft veröffentlicht.

Notizen: A scholarly account of the formative discussions, the founding and the first 20 years of the Photogrammetric Society was published in 1971 and republished in 1974. This present review concentrates on the latter years of the life of the Photogrammetric Society prior to its merger with the Remote Sensing Society in 2001.The authors joined the Photogrammetric Society in 1960 and were conspicuous in its affairs for many years. Although both occupied the Society's presidential chair, they also fulfilled several other roles in its efficient management. Atkinson's first contribution to the Photogrammetric Record was published in 1968 and Newton's in 1971.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn a publié en 1971 un compte-rendu détaillé des 20 premières années de la “Photogrammetric Society”, à commencer par les discussions qui présidèrent è sa fondation. Ce récit fut republié en 1974. On se focalise dans cet article sur les dernières années d'activité de la “Photogrammetric Society” qui aboutirent à sa fusion avec la “Remote Sensing Society” en 2001.Les deux auteurs adhérèrent à la “Photogrammetric Society” en 1960 et y furent d‘éminents animateurs pendant de nombreuses années. Tous deux occupèrent le poste de président de cette Association mais remplirent égulement plusieurs autres fonctions qui contribuèrent à une gestion efficace. La première intervention d'Atkinson dans le Photogrummetric Record remonte à 1968, et celle de Newton à 1971.〈section xml:id="abs1-3"〉〈title type="main"〉ZusummenfussungEine wissenschaftliche Abhandlung über die Diskussionen zur Gründung, die Gründung selbst und die ersten 20 Jahre der Photogrammetrischen Gesellschaft wurde in 1971 publiziert und in 1974 wiederholt. Dieser aktulle Rückblick konzentriert sich auf die darauffolgenden Jahre der Photogrammetrischen Gesellschaft bis hin zur Vereinigung mit der Gesellschaft für Fernerkundung in Jahre 2001.Die Autoren wurden 1960 Mitglieder in der Photogrammetrischen Gesellschaft und trugen viele Jahre massgeblich zu deren Aktivitäsidenten der Gesellschaft auch verschiedene andere Aufgaben im Management wahrgenommen. Der erste Beitrag von Atkinson im Photogrammetric Record erschien 1968, der erste von Newton in 1971.

Notizen: The determination of the attitude, the position and the intrinsic geometric characteristics of the camera is recognised as the fundamental photogrammetric problem. It can be summarised as the determination of camera interior and exterior orientation parameters, as well as the determination of 3D coordinates of object points. The term “exterior orientation” of an image refers to its position and orientation related to an exterior (object space) coordinate system. Several methods can be applied to determine the parameters of the orientation of one, two or more photos. The orientation can be processed in steps (as relative and absolute orientation) but simultaneous methods (such as bundle adjustments) are now available in many software packages. Several methods have also been developed for the orientation of single images. They are based in general on geometric and topological characteristics of imaged objects.This paper presents a survey of classical and modern methods for the determination of the exterior parameters in photogrammetry, some of which are available as software packages (with practical examples) on the Internet. The methods presented are classified in three principal groups. In the first. a selection of approximate methods for applications that do not require great accuracy is presented. Such methods are also used to calculate values required for iterative processes. In the second group, standard point-bused methods derived from collinearity, coplanarity or coangularity conditions are briefly reviewed, followed by line-based approaches. The third group represents orientation methods based on constraints and on concepts of projective geometry, which are becoming of increasing interest for photogrammetrists. In the last section, the paper gives a summary of existing strategies for automatic exterior orientation in aerial photogrammetry.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméLa détermination de l'attitude, de la position et des caractéristiques intrinsèques de la chambre photographique constitue un problème fondamental en photogrammétrie. Il se résume à la détermination des paramètres de l'orientation de la chambre de prise de vue (paramètres des orientations externe et interne), ainsi qu'à la détermination des coordonnées 30 des points de l'objet. L'orientation externe se rapporte à la détermination de la position et de l'orientation d'une chambre par rapport à un système externe de coordonnées. Différentes méthodes peuvent être utilisées pour calculer les éléments dorientation externe d'une photo, d'un couple ou de plusieurs photos. Le calcul de l'orientation peut être réalisé par étapes (par exemple les orientations relative et absolue) mais les méthodes simultanées (la compensation par faisceaux par exemple) sont actuellement proposées dans la plupart des logiciels. Plusieurs méthodes ont aussi été développées pour l'orientation d'images isolées. Ells sont basées en général sur les caactéristiques géométriques et topologiques des objets photographiés.Dans cet article on présente un ensemble de méthodes classiques et modernes pour la détermination des paramètres de l'orientation externe, certaines d'entre elles étant téléchargeables sous la forme d'applications sur Internet. Les méthodes présentées sont classées en trois groupes principaux. Le premier groupe contient une sélection de méthodes approximatives utilisées d'habitude quand une grande précision n'est pas exigée, ou encore pour calculer des vuleurs approchées des paramètres extrinsèques requises pour les méthodes itératives rigoureuses. Dans le deuxième groupe, on rappelle brièvement les jondements des méthodes basées sur les conditions photogrammétriques fondamentales (la colinéarité, la coplanéité et la coangularité). Dans ce groupe, les méthodes basées sur l'extraction des points ou des lignes sont également abordées. Le troisième groupe traite des méthodes d'orientation basées sur les contraintes et les concepts de la géométrie projective, de plus en plus utilisées par les photogrammètres. Le dernier paragraphe se rapporte aux méthodes destinées à automatiser le calcul de l'orientation externe en photogrammétrie aérienne.〈section xml:id="abs1-3"〉〈title type="main"〉ZusummenfussungDie Bestimmung der Neigung, der Position und den geometrischen parametern der Kamera wird als das fundamentale Problem der Photogrammetrie angesehen. Es kann zusammenfassend sowohl als die Bestimmung der Parameter der inneren und äusseren Orientierung der Kamera angesehen werden, als auch als die Bestimmung von 3D Koordinaten von Objektpunkten. Der Ausdruck “äussere Orientierung” eines Bildes bezieht sich auf die Lage und Orientierung bezogen auf ein äusseres (Objektraum-) Koordinatensystem. Es können verschiedene Methoden angewandt werden, um die Parameter von einem, zwei oder mehreren Bildern zu bestimmen. Die orientierung kann in Schritten erfolgen, was als Relative und Absolute Orientierung bezeichnet wird, aber auch simultane Methoden, wie die Bündelausgleichung, sind in vielen Softwarepaketen implementiert. Es wurden auch Methoden für die Orientierung von Einzelbildern entwickelt, die geometrische und topologische Eigenschaften der abgebildeten Objekte nutzen. In diesem Beitrag wird Beitrag wird eine Studie klassischer und moderner Methoden der Photogrammetrie zur Bestimmung der Parameter der äßeren Orientierung vorgestellt, wovon einige in Softwarepaketen zur Verfügung stehen, die von praktischen Beispielen im Internet ergänzt werden. Die untersuchten Methoden werden in drei Hauptgruppen eingeteilt. In einer ersten Gruppe werden Näherungslösungen vorgestellt, die für Anwendungen mit geringen Genauigkeitsanforderungen geeignet sind. Diese Methoden werden ansonsten für die Näherngswertberechunggen für iterative Prozesse verwendet. IN der zweiten Gruppe werden zuerst die punktbasierten Standardmethoden vorgestellt, die von Bedingungen zur Kollinearität. Koplanarität und Kowinkligkeit abgeletet sind. Danach folgen linienbasierte Ansätze. Die dritte Gruppe umfasst Orientierungsmethoden, die auf Zwangsbedingungen und auf Konzepte der projektiven Geometrie aufbauen, die für Photogrammeter von zunehmendem Interesse sind, Im letzten Abschnitt wird eine Zusammenfassung existierender Strategien für eine automatische äussere orientierung in der Luftbildphotogrammetrie gegeben.

Notizen: The aim of this paper is to offer regional evidence from Spain on alcohol abuse among adolescents. Specifically, we identify the determinants of the decision to abuse alcohol with respect to the five most important regions of Spain, as well as for the country as a whole. To this end, we estimate Probit specifications using data drawn from the Spanish Surveys on Drug Use in the School Population corresponding to 1994, 1996 and 1998. The results first reveal patterns that are qualitatively similar, but quantitatively different. Similarly, it would appear that economic policies aimed at reducing the access of adolescents to alcohol may have a positive effect on reducing abuse. Finally, the results suggest that encouragement be given to healthy habits among young people, as well as to the fight against education failure and the launching of information campaigns that accurately portray the current lifestyle of adolescents.

Notizen: The aim of this study was to determine the knowledge and acceptability of soymilk (defined as consumption pattern/usage and taste) by adult consumers, residing in different socio-economic areas (low vs. high) in Cape Town. The study population of 214 participants were selected using convenience sampling. A questionnaire was developed in order to obtain demographic data (four items); basic general knowledge of soymilk (four items); and acceptability of the tested products (consumption patterns and taste) (eight items). There was a significant difference between the two groups (P = 0.000) regarding basic knowledge of soymilk, with significantly more in the high socio-economic area (HSEA) having a score of at least 75%. Gender (P = 0.082) and age (P = 0.122) did not have a significant impact on the consumption patterns of soymilk. There was no significant difference between the two groups with respect to current usage (P = 0.228) and frequency of use (P = 0.213) of soymilk. However, a significantly smaller group (P = 0.000) of participants in the low socio-economic area had previously tasted soymilk compared with those in the HSEA (16.7% vs. 41.5%; P = 0.000). In conclusion, socio-economic status appeared to be associated with knowledge of soymilk. No significant differences with regard to gender, age or current usage in the two groups studied were noted.

Notizen: SYNOPSIS. Cortical ultrastructure of the scuticociliates Dexiotricha media and Dexiotricha colpidiopsis was investigated. The following elements of the somatic cortex were studied: the cell membrane, alveolar membranes and the epiplasm, kinetodesmal fibers, postciliary and transverse microtubular ribbons, and transverse fibers associated with single and paired kinetosomes; mitochondria and single microtubules located in interkinetal ridges; mature and early extrusion stages of mucocysts: the expulsion vacuole pore and tube, the nephridioplasm and the cytoproct. In the buccal cortex, the paroral kinety-ribbed wall complex, the 3 polykineties, and the cytostome-cytopharynx were investigated.Comparative survey of ciliate ultrastructure indicates 2 principal orientation patterns for kinetodesmal and postciliary fibers, recognition of which leads to reevaluation of the theory of paroral kinety formation and the ideas of homology based on this theory. Ultrastructurally, the scuticociliates are not distinct from tetrahymenines and peniculines; the 3 groups appear to be 1 assemblage.

Notizen: SYNOPSIS. In this study the characteristics of the synthesis of DNA and RNA in the nuclei of Loxodes were investigated. Loxodes striatus is a primitive ciliate with 2 pairs of structurally differentiated diploid nuclei, the macro- and micronuclei. The macronuclei are differentiated morphologically into a clearly recognizable central core and an outer zone.To determine DNA and RNA synthesis, individual organisms were analyzed by autoradiography after incubating groups of cells with a 3H-labeled precursor ([3H]thymidine for DNA and [3H]uridine for RNA).The following observations were made: (A) All portions of macro- and micronuclei appeared to contain DNA as judged by the localizations of incorporated [3H]thymidine. (B) The macro- and micronuclei did not synthesize DNA at the same time; moreover, the duration of DNA synthesis in the former was much longer than of the latter nucleus. (C) Replication of DNA in the inner core and outer zone of the macronucleus occurred at separate times with little if any overlap. (D) All of the detectable [3H]uridine incorporation was found in the macronucleus and none in the micronucleus. Within the macro-nucleus the central core was more heavily labeled. (E) The quantitative differences in the label of the different components of the nuclear complex were investigated. (F) Contrary to the previously reported information our results suggest that DNA synthesis can occur in adult macronuclei.The possible explanation of these results is discussed in the context of the nuclear evolution of ciliates and of recent information on nuclear differentiation.

Notizen: SYNOPSIS. Eimeria dispersa (turkey strain) and Eimeria gallopavonis sporozoites were inoculated into primary cultures of chicken kidney (CK) and turkey kidney (TK) cells. Eimeria dispersa sporozoites were more infective in either cell type than those of E. gallopavonis: at 4 hr, the percentage of infection was 67-98 for E. dispersa but only 23-56 for E. gallopavonis. E. dispersa also survived better in culture: at 2 days, losses of E. dispersa in both cell types were only 4-19%, whereas losses of E. gallopavonis were 35-47% in TK cells and 60–95% in CK cells. However, E. gallopavonis developed further than E. dispersa. Location and increase in numbers of intracellular stages at 4 days indicated that E. dispersa proceeded through 2 schizogonic generations before development stopped.

Notizen: Book reviewed in this article:Cuatrecasas, P. & Greaves, M. F., eds. 1976, Receptors and Recognition, Vol. I, Series A.

Notizen: SYNOPSIS. A mating type analysis was performed on 231 isolates of the cellular slime mold, Polysphondylium pallidum found in 61 samples collected in eastern North America between northern Florida and southern Canada. Seventy-eight percent of the isolates belonged to one of 2 mating types; 18% were incapable of mating with any partner; 3% were homothallic; and 1%, consisting of 2 isolates from a Florida sample, belonged to a separate breeding group. It is suggested that the majority of isolates represent a species capable of local genetic adaptation to a niche, the parameters of which undergo considerable variation over space and time.

Notizen: Book reviewed in this article:Avakyan, A. A. 1976. Atlas Anatomii Prosteishikh, Patogen-nykh dlya Cheloveka i Zhivotnykh.

Notizen: SYNOPSIS. Cell size, macromolecular composition, carbohydrate utilization patterns, and O2 concentrations were measured throughout the growth stages of Naegleria gruberi in agitated cultures in a complex medium. Biphasic logarithmic growth occurred during the initial 83 hr of growth and the mean generation time was 7.0 hr and 19 hr during initial and secondary log growth stages, respectively. The maximum yield was 5 × 10* amebaeJml. The pH rose rapidly (1 pH unit) during the secondary log growth phase (52-83 hr) and continued into the stationary growth phase (83-120 hr). Dry weight, total protein, carbohydrate, and RNA per ameba increased just before the secondary log growth phase. RNA increased 31% to 35% per ameba at the end of each phase of log growth. DNA increased ∼ 2-fold throughout the different growth phases. Average cell size increased 90% during biphasic log growth then decreased during stationary phase. O2 tension decreased from 100% to 18% of saturation during the biphasic growth phase, then increased during stationary growth to near 100% saturation. Glucose and total carbohydrate assays showed little utilization of those substrates throughout the growth stages. Naegleria gruberi presumably has a predominantly aerobic metabolism, also its metabolism may change during the different growth phases.

Notizen: RESUME. L' étude ultrastructurale de la grégarine Gregarina blaberae a été entreprise après mise au point d'un protocole d'infestation expérimentale de larves vierges de Blattes, Blaberus craniifer. Les observations en microscopie électronique, effectuées en fonction du temps, ont permis de suivre le développement du sporozoïte, ainsi que la croissance et l' évolution du trophozoïte.La croissance est spectaculaire puisqu'en 18 jours elle entraîne la transformation du germe infectieux ou sporozoïte (L = 15 μm, φ=1 μm) en un céphalin—trophozoïte fixéà l' épithélium intestinal—de 250 μm de longueur pour un diamètre de 65 μm. L'organisation ultrastructurale du sporozoïte ne diffère pas de celle de la plupart des sporozoïtes des autres sporozoaires étudiés jusqu' à présent, le conoïde et les corps denses sont présents. La paroi est trimembranaire. toutefois le complexe membranaire interne présente quelques interruptions. Les premiers dictyosomes s' élaborent à partir de l'enveloppe nucléaire. La migration du noyau et des corps denses, puis la régression de toutes les formations caractéristiques du sporozoïte et l' établissement d'une zone corticale venant coiffer l' épimérite, ont lieu dans les 48 heures suivant l'infestation et marquent la transformation sporozoïte-céphalin.L' évolution du céphalin, se poursuit par la formation des ébauches des plis épicytaires qui s'effectue à partir du 3éme jour du développement à la base du deutomérite. Un système régulier de plis longitudinaux ou épicyte s' établit ainsi sur toute la partie extra-cellulaire de la grégarine. Dès les 4éme-5éme jours de développement, un réseau vacuolaire et un chondriome important se différencient dans l' épimérite, tandis qu'un septum de nature fibrillaire isole le protomérite du deutomérite. Le stade suivant—à partir du 6éme jour—est marqué par une ségrégation du matériel glucidique au niveau de ces 2 segments.Le modèle étudié permet de préciser le rôle de l' épimérite dansla nutrition du parasite, l' évolution du chondriome et des membranes corticales au cours de la phase de croissance végétative des grégarines polycystidées.

Notizen: SYNOPSIS. Stomatogenesis was studied in the heterotrich ciliate Blepharisma japonicum stained with protargol. During binary fission not only is a new oral apparatus made for the posterior daughter, but the already existing oral apparatus of the parent cell is reorganized, i.e. partially disassembled and then subsequently reassembled to provide a functional feeding apparatus for the anterior daughter cell. These morphogenetic events, requiring 21/2 to 3 hr, are complete by the time the anterior and posterior daughters separate.In preparation for division, an oral anlage is formed by the rapid proliferation of kinetosomes along 4–5 stomatogenic kinetics directly subtending the cytostome. This field of randomly oriented kinetosomes ultimately gives rise to the feeding apparatus of the posterior daughter cell. Early in division, the oral anlage separates into 2 longitudinal fields of kinetosomes: one is destined to give rise to the undulating membrane and the other forms the adoral zone of membranelles. Shortly after the anlage is established posterior to the cytostome, reorganization of the existing functional mouth is initiated. The morphologic changes associated with this dedifferentiation-redifferentiation sequence lead to the formation of an oral apparatus for the anterior daughter and cannot be distinguished from those characteristically seen during physiologic reorganization.

Notizen: SYNOPSIS. The effects of age and sex of the cat on oocyst shedding, multiplication of Toxoplasma gondii in tissues of cats, and acquisition of immunity were investigated after oral inoculation of cats with Toxoplasma cysts. Twenty-five cats varying in age from 1 week to 39 months were killed 7-97 days after inoculation with T. gondii. Homogenates of brain, heart, mesenteric lymph nodes, retina, and blood from these cats were inoculated into mice to test for Toxoplasma infectivity. Toxoplasma was isolated more frequently and in higher titers in mice receiving inocula from cats of the youngest age group (1 week old). Toxoplasma gondii was isolated from tissues of only 2 of 21 cats older than 2 months (at the time of inoculation), although all of the animals shed oocysts within 1 week after ingesting the parasites.The number of oocysts shed varied among littermates of the same sex and between sexes. Generally, cats younger than 12 months shed more oocysts than older cats. The number of oocysts shed by older cats varied considerably; males generally shed more oocysts than the females. However, the numbers of cats examined were too small for statistical comparison. Nevertheless, the observations suggest that cats older than 12 months should not be used in experiments where numbers of oocysts shed is critical.

Notizen: SYNOPSIS. Changes in the metabolism of Crithidia fasciculata ATCC 11745 when grown in the presence of ethidium bromide were studied. Ethidium bromide-grown cells had decreased respiratory activity as measured by oxygen consumption. More than 50% of the organisms cultivated in a defined medium containing 1.0 mg/liter of ethidium bromide became dyskine-toplastic and had decreased activities of particulate succinate and NADH-linked dehydrogenases as well as of soluble isocitrate dehydrogenase. These cells also had increased activities of particulate α-glycerophosphate dehydrogenase, soluble α-glycerophosphate dehydrogenase, malic enzyme, hexokinase, and malate dehydrogenase. Ethidium bromide-grown cells had a lower level of ATP and contained less DNA than cells grown in its absence.

Notizen: SYNOPSIS. Phenol is the major organic constituent of coal-conversion scrub water and is therefore a potential environmental contaminant. After Tetrahymena pyriformis strain GL-C, syngen 1 was exposed to phenol, its behavior, cytology, respiration, and growth rates were examined. Concentrations ≥ 75 mg/liter alter cell motility, shape, and contractile vacuole activity. O2 uptake was abruptly reduced within 3 min of exposure to phenol in concentrations as low as 10 mg/liter. Concomitantly there was an increase in the electron density of the mitochondrial matrix. Recovery to normal rates of O2 consumption was paralleled by a return to normal matrix density. Alterations of mucocysts, pellicle, and glycogen were also observed. The length of lag phase growth curves increased generally in proportion to concentration of toxicant. Phenol, however, did not affect the rate of cell multiplication during the exponential growth phase. The potential use of this system to examine the effects of other possible organic pollutants is discussed.

Notizen: SYNOPSIS. Sporulated oocysts of Eimeria nieschulzi Dieben, a rat coccidium, were exposed for 1 hr to Cobalt-60 γ-radiation (15, 30. or 60 k-rads), to heat (35, 40, or 45 C). or to both concurrently (15, 30, or 60 k-rads at 35 C) to compare the excystation capabilities of treated vs nontreated parasites. Intact, treated oocysts appeared structurally unaltered when viewed with the light microscope. Excystation of sporozoites occurred in all treated groups when their sporocysts were exposed to a trypsin-sodium taurocholate (TST) fluid, but after 150 min in TST the excystation rate was significantly lower than in non-treated sporocysts. Sporozoites which excysted from treated sporocysts were abnormal both in the excystation process and in their form and movement once outside the sporocyst.

Notizen: SYNOPSIS. Mitochondria were isolated from Euglena gracilis strain Z by pressure-breakage of the cells and sucrose-cushion centrifugation. Multiple peaks (2-4) were observed in the rate of phosphorylation with Mg-ADP-phosphate concentration curves. The phosphorylative and oxidative activities were highest with NADH as the substrate, moderate with succinate, and lowest with glutamate. Inhibition of phosphorylation with 2,4-dinitrophenol and carbonyl cyanide, m-chlorophenylhydrazone gave sigmoidal concentration curves, with the extent of inhibition by DNP depending on the substrate used. Inhibition of phosphorylation by valinomycin, atractyloside, or carboxyatractyloside was only ∼ 60%. Oligomycin inhibited phosphorylation in 2 phases at low and high concentrations; it inhibited Mg-ATPase in a sigmoidal fashion. Both phosphorylation and oxidation had discontinuities in Arrhenius plots at 34 C and 18 C.The relative Mg2+-dependent nucleoside triphosphatase activity was: 1 for ATP and GTP, 0.6 for ITP, 0.15 for CTP and and UTP; with Ca2+ in place of Mg2+ this activity was 0.35. Both DNP and CCCP stimulated the Mg-ATPase 50-200%. The optimal pH for the stimulation was ∼ 7 regardless of the uncoupler used, and ∼ 8 without the uncouplers.The few differences observed between mitochondria from Euglena and those from other sources are probably due to the fragmentation of the reticular mitochondrial structure during isolation and not to unique characteristics of these mitochondria.

Notizen: Book reviewed in this article:Jennings, D. H., Lee, D. L., eds. 1975. Symbiosis (Symposia of the Society for Experimental Biology Number XXIX).

Notizen: Book reviewed in this article:Stanier, R. Y., Adelberg, E. A. & Ingraham, J. L. 1975. The Microbial World, 4th ed.

Notizen: SYNOPSIS. Discotricha papillifera Tuffrau, a marine interstitial ciliate, is redescribed with the aid of light, scanning, and transmission electron microscopy from cells collected at a New Hampshire beach. Presence of primitive membranelles as well an an advanced stomatogenesis is demonstrated. The ultrastructure, including a unique membrane-bounded septate structure, is described. The cell is tentatively placed in the nassulid suborder Microthoracina, but affinities with other groups are discussed.

Notizen: Book reviewed in this article:Noble, E. R., Noble, G. A. 1976. Parasitology. The Biology of Animal Parasites. 4th Ed.

Notizen: RESUME. L' étude détaillée du cortex et des organelles buccaux adoraux d' Espejoia montre que ce Cilié possède une organisation ultrastructurale comparable à celle des Tétrahyméniens. Tout en restant conforme au plan général d'organisation de ces derniers, des variations spécifiques décelées tant au niveau du cortex d'une part, que des membranelles, d'autre part, font ressortir des affinités trés marquées pour le genre Glaucoma et autres Ciliés voisins. En conséquence, en nous appuyant en outre sur les données récentes de la morphogenèse, nous confirmons la position d' E. mucicola parmi les Tetrahymenina, dans la famille des Glaucomidae.

Notizen: SYNOPSIS. Budding and metamorphosis in the suctorian ciliate, Discophrya collini, have been investigated by scanning electron microscopy. The adult body form, tentacles, stalk, and attachment disk are described. A field of depressions or small pits was observed in the pellicle of adult suctorians in the early stages of bud formation. These pits deepen and coalesce until one large pore, the birth pore, remains. Cilia protrude through the pore, and as eversion of the bud proceeds the meridional arrangement of the larval ciliation is evident. After eversion is completed, a pronounced division furrow is found between the adult and soon-to-be-released swarmer. The stalk-forming region is seen on swarmers. Metamorphosing swarmers produce tentacles upon settling before any indication of ciliary resorption. Resorption of cilia and change in body form occur progressively with the production of the attachment disk and stalk.

Notizen: Book reviewed in this article:Cohen, S., & Sadun, E. H., eds. 1976. Immunology of Parasitic Infections.

Notizen: Book reviewed in this article:Herman, C. M., Greiner, E. C., Bennett, G. F. and Laird, M. 1976. Bibliography of the Avian Blood-Inhabiting Protozoa.

Notizen: SYNOPSIS. Marine, sediment-dwelling ciliates were examined for cytochrome oxidase activity by a cytochemical method and for fine structural details. Species of Plagiopylidae (Trichostomatida), i.e. Plagiopyla frontata, Sonderia vorax and Sonderia sp., and of Heterotrichida, i.e., Parablepharisma pellitum, Parablepharisma sp., Metopus contortus, Metopus vestitus and Caenomorpha capucina; previously considered to be obligate anaerobes because of their sulfide-containing habitat, do not have cytochrome oxidase activity or mitochondria with cristae or tubuli. The evolutionary origin and significance of anaerobic ciliates is discussed. Most of the anaerobic ciliates harbor a flora of ecto- and endosymbiotic bacteria as demonstrated by transmission and scanning electron micrographs. It is speculated that the bacteria may utilize the metabolic end products of the protozoa for growth and energy yielding processes. These associations are also compared with other, previously described cases of symbiosis involving prokaryotes and protozoa.

Notizen: . Microtubule dynamics in Paramecium caudatum were investigated with an anti-α-tubulin antibody and a microinjection technique to determine the function of microtubules on micronuclear behavior during conjugation. After meiosis, all four haploid micronuclei were connected by microtubular filaments to the paroral region and moved close to this region. This nuclear movement was micronucleus-specific, because some small macronuclear fragments transplanted from exconjugants never moved to the region. Only one of the four germ nuclei moved into the paroral cone and was covered by microtubule assembly (the so-called first assembly of microtubules, AM-I). This nucleus survived there, while the other three not in this region degenerated. The movement of germ nucleus was inhibited by the injection of the anti-α-tubulin antibody. The surviving germ nucleus divided once and produced a migratory pronucleus and a stationary pronucleus. Prior to the reciprocal exchange of the migratory nuclei, microtubules assembled around the migratory pronuclei again (the so-called second assembly of microtubules, AM-II). Then, the migratory pronucleus moved into the partner cell and fused with the stationary pronucleus. Thus, microtubules appear to be indispensable for nuclear behavior: they enable migration of postmeiotic nuclei to the paroral region and they permit the survival of the nucleus at the paroral cone.

Notizen: . This work reports the characterization of an arginine kinase in the unicellular parasitic flagellate Trypanosoma brucei, the etiological agent of human sleeping sickness and Nagana in livestock. The arginine kinase activity, detected in the soluble fraction obtained from procyclic forms, had a specific activity similar to that observed in Trypanosoma cruzi, about 0.2 μmol min−1mg−1. Western blot analysis of T. brucei extracts revealed two bands of 40 and 45 kDa. The putative gene sequence of this enzyme had an open reading frame for a 356-amino acid polypeptide, one less than the equivalent enzyme of T. cruzi. The deduced amino acid sequence has an 82% identity with the arginine kinase of T. cruzi, and highest amino acid identities of both trypanosomatids sequences, about 70%, were with arginine kinases from the phylum Arthropoda. In addition, the amino acid sequence possesses the five arginine residues critical for interaction with ATP as well as two glutamic acids and one cysteine required for arginine binding. The finding in trypanosomatids of a new phosphagen biosynthetic pathway, which is not present in mammalian host tissues, suggests this enzyme as a possible target for chemotherapy.

Notizen: The changes in porosity and elastic moduli of YSZ-containing nickel-based anode materials for solid oxide fuel cells were studied as a function of the fraction of reduced NiO. Anode samples were reduced in a gas mixture of 4% hydrogen and 96% argon for different periods of time at 800°C and their Young's and shear moduli were determined afterward at room temperature using resonant ultrasound spectroscopy and impulse excitation. It was found that the magnitude of Young's and shear moduli decreased significantly with increasing fraction of reduced NiO and that the magnitude of the elastic moduli of a fully reduced Ni–YSZ anode was ∼45% lower than that of unreduced NiO–YSZ. Because the elastic moduli of NiO are close to those of Ni, the observed decrease in the magnitude of the elastic moduli was found to be caused mainly by the significant increase in the porosity of the sample as a result of NiO reduction. Expressions are presented for the amount of porosity and the magnitude of the elastic moduli as a function of the fraction of reduced NiO.

Notizen: Two- and three-dimensional SiCr/SiC composites have been prepared starting from Tyranno SA(tm) fiber preforms. Preform densification has been performed by a modified preceramic polymer impregnation and pyrolysis (PIP) process consisting of filling the preform large interbundle voids with SiC powder before the PIP process. This step was accomplished by low-pressure infiltration of a SiC powder dilute slurry through the preform thickness. Specimens were further processed with polymer impregnation and pyrolysis to determine the effects on structural, thermal, and mechanical properties of the obtained composites. High-temperature pyrolysis treatment, which promoted polymer derived SiC matrix crystallization, markedly increased thermal diffusivity.

Notizen: Carbon is commonly added to sulfate-fined silicate-glass batches to enhance the fining process. Reactions between carbon and Na2SO4 modify the SOx emissions from Na2SO4 decomposition. Fourier-transform infrared (FTIR) spectrometry is used to analyze the emission of air pollutants from the isothermal decomposition of Na2SO4 + C undertaken using thermogravimetric analysis (TGA). The FTIR spectrometer is calibrated using standard gas mixtures containing CO, CO2, SO2, NO, and NO2. The collected spectra are quantified using the classical least-squares (CLS) approximation. The TGA-FTIR system provides SOx, and COx, concentrations versus time data from the isothermal decomposition of Na2SO4, in the presence of a carbon black. Mass spectrometry (MS) complements FTIR by being able to detect SO(g).

Notizen: Different ratios of the precursor phases of SrFeO3–x (SFO) and SrMoO4 (SMO) were used to prepare Sr2FeMoO6 (SFMO) by a solid-state reaction. X-ray diffraction was used to identify the phases. A residual SMO was observed to exist in the sample with an SFO/SMO ratio of 0.9:1. The sample with a residual SMO phase had higher resistivity, lower magnetization, but higher low-field magnetoresistance (LFMR). High-resolution transmission electron microscopy was used to identify the compositions and phases. Nanometer-sized amorphous-like clusters of SMO phase were located inside the grains rather than at grain boundaries; however, some boundaries were rich in the strontium ion. The possible mechanisms for the conduction and the increase of LFMR of SFMO are discussed.

Notizen: Submicro- and nano-sized liquid-phase-sintered SiC ceramics were mechanically tested by nanoindentation in the peak load range 5–400 mN. The submicro-sized sample showed a marked indentation size effect which the nano-sized samples did not exhibit. The relevance of indentation depth with respect to the microstructural scale has been outlined. In the investigated grain-size range, the hardness dependence on the grain size could be described by a load-dependent inverse Hall–Petch relation. Young's modulus was less microstructure- and load-dependent. Because of the very fine microstructure, the nano-sized SiC materials gave lower elastic values than the submicro-sized SiC ceramic.

Notizen: Samples of composition Ba1−xLaxTi1−x/4O3, x= 0, 0.003, 0.03, and 0.10, were prepared by an alkoxide sol–gel route with final firing of ceramics at 1100°C, 2 h in air. All samples showed bulk insulating behavior with no evidence of semiconductivity caused by either direct donor doping or oxygen loss.

Notizen: We have studied the rheological property evolution and hydration behavior of white and ordinary portland cement (type I) pastes and concentrated cement–polyelectrolyte suspensions. Cement composition had a marked effect on the elastic property evolution (G′(t)) and hydration behavior of these suspensions in the presence of poly(acrylic acid)/poly(ethylene oxide) copolymer (PAA/PEO), even though their affinity to adsorb such species was nearly identical. Both white and ordinary portland cement pastes exhibited G′0 values of ∼104 Pa and fully reversible G′(t) behavior until the onset of the acceleratory period (t= 2 h), where the pastes stiffened irreversibly. In contrast, cement–PAA/PEO suspensions exhibited G′0 values of ∼1 Pa and G′(t) behavior comprised of both reversible and irreversible features. Interestingly, ordinary portland cement–PAA/PEO suspensions experienced a gel-to-fluid transition on high shear mixing at short hydration times (〈1 h), and the particle network did not rebuild until ∼24 h of hydration. In sharp contrast, white portland cement–PAA/PEO suspensions remained weakly gelled throughout the initial stage of hydration even after high shear mixing. At longer hydration times (〉1 h), both cement–PAA/PEO suspensions exhibited G′i(t) ∼ exp(t/τc) with τc values of 5.6 and 1.3 h for ordinary and white portland cement, respectively. Our observations suggest that hydration phenomena impact interparticle forces during early stage hydration and, ultimately, lead to initial setting through the formation of solid bridges at the contact points between particles within the gelled network.

Notizen: A new ceramic freeze-casting technique capable of manufacturing near room temperature with a sublimable vehicle was accomplished. Fluid-concentrated slurries of Al2O3 powder in molten camphene (C10H16) were prepared at 55°C. These slurries were quickly solidified (frozen) at room temperature to yield rigid solid green bodies, followed by frozen camphene removal by sublimation (freeze-drying) with negligible shrinkage. Sintering without any special binder burnout process yielded sintered bodies with over 98% theoretical density. The proposed advantages include (1) elimination of extremely cold temperatures, (2) elimination of troublesome binder burnout process, and (3) fast manufacturing cycle due to quick solidification.

Notizen: Dense composites in the Ti-B-N system have been produced by reactive hot pressing of titanium and BN powders. The effect of the addition of a small amount of nickel (1–3 wt%) on the reaction kinetics and densification of TiN–TiB2 (40 vol%) composite has been studied. Composites of ∼99% of theoretical density have been produced at 1600°C under 40 MPa for 30 min with 1% nickel. The hardness and fracture toughness of these composites are 24.5 ± 0.97 GPa and 6.53 ± 0.27 MPa·m1/2, respectively. The microstructural studies on samples produced at lower temperatures indicate the formation of a transient liquid phase, which enhances the kinetics of the reaction and densification of the composite.

Notizen: This paper presents new findings on ultrasonic spray pyrolysis of zirconium hydroxyl acetate precursor drops whose sizes were precisely measured using laser light diffraction technique. Precursor concentration plays a predominant role in determination of product particle size. At 0.01 wt% precursor concentration, conventional spray pyrolysis at 750°C using precursor drops 5–8 μm in diameter, generated by an ultrasonic nebulizer at 2.66 MHz, yielded uniform spherical yttria-stabilized zirconia (YSZ) particles 73 nm in diameter measured by scanning electron microscopy. The YSZ particle diameters were much smaller than those predicted by the one-particle-per-drop mechanism. Under similar reaction conditions, the high-throughput ultrasound-modulated two-fluid (UMTF) spray pyrolysis of larger precursor drops (28-μm peak diameter) also yielded spherical dense particles; they were significantly smaller in size than those produced by the low-throughput conventional ultrasonic spray pyrolysis of smaller drops (6.8-μm peak diameter).

Notizen: Thermoelectric elements consisting of the layered polycrystalline materials of Al-doped ZnO and NaCo2O4 were prepared using the pulse electric-current sintering (PECS) method at 900°C for 3 min. Direct contact between the polycrystalline Al-doped ZnO and the NaCo2O4 was obtained in a single-step process for the stacked powders. The electrical conductivities of the polycrystalline materials prepared by PECS were higher than those of materials prepared by conventional sintering, despite their porous structure. The thermoelectric voltage of the 1-mol%-Al-doped ZnO and NaCo2O4 polycrystalline element (measuring ∼6 mm × 3 mm × 15 mm) was 83 mV at dT= 500 K, when the junction of the elements was at 800°C.

Notizen: Pb(Zr,Ti)O3–Pb(Mn1/3 Nb2/3)O3 (PZT–PMnN) system has been studied for high-power piezoelectric applications. This study investigates this system to find out the composition with high-power density piezoelectric characteristics and low tem-perature coefficient of resonance frequency (TCF). It was found that the composition 0.9PZT–0.1PMnN (Zr/Ti = 0.51/0.49) modified with 6 mol% Sr exhibits a TCF of −8 ppm/°C (−20 to +80°C). Further, the dielectric and piezoelectric properties of this composition are as follows: kp= 0.53; Qm= 800; d33= 274; ε33/ε0= 1290 and tan δ=1.1%, which shows the suitability of this composition for ultrasonic devices used under fluctuating thermal environment.

Notizen: Beam bending is an excellent method for measuring low permeabilities (≤10−18 m2) in homogeneous materials, because it is fast, requires no high pressure, and provides a concurrent measurement of the modulus of the material. The method was previously analyzed and substantiated for cylindrical or square beams. Recently, the analysis was extended to include isotropic and transversely isotropic rectangular beams. In this paper, the analysis is applied to measurements performed on cement paste, and it is shown that the solution for isotropic rectangular beams accounts for changes in the hydrodynamic behavior caused by changing the aspect ratio of the sample. The permeability and elastic modulus results are verified through comparison to previous measurements on cylindrical beams.

Notizen: The deformation behavior of boron- and carbon-doped β-silicon carbide (B,C-SiC) with an average grain size of 260 ± 18 nm containing 1 wt% boron was investigated by compression testing at elevated temperatures. Extensive grain growth during deformation was observed. The stress–strain curves were compensated for grain growth by assuming power-law type of dependence on grain size and strain rate. The stress exponent n was ∼1.3 and the grain size exponent p was ∼2.7 at temperatures ranging from 1593° to 1758°C. The apparent activation energy of deformation Qd was ∼760 kJ/mol, which was lower than the activation energy for lattice diffusion of silicon and carbon in SiC and higher than that for grain-boundary diffusion of carbon in SiC. These results suggest that the deformation mechanism of the fine-grained B,C-SiC is grain-boundary sliding accommodated by the grain-boundary diffusion.

Notizen: Chromium-containing stainless steel (SS) is a prospective material for use as an interconnect in solid oxide fuel cells (SOFCs). However, during operations at high temperatures, the growth of oxide scales causes the performance of the interconnect and SOFC as a whole to deteriorate. The coating of SS 446 with a conducting perovskite is a potential method of slowing the growth of oxide scale and, therefore, improving overall SOFC performance. In the present research, the structural characterization of a pure LaCrO3 thin film on the SS 446 substrates has been performed as a model material that can be used as a barrier coating for the metallic interconnect. The deposition of an amorphous La-Cr-O thin film on SS 446 was performed using radio-frequency (rf) magnetron sputtering. The deposited amorphous film was annealed in air to form the desired perovskite phase. The film underwent an amorphous to LaCrO4 phase transition during annealing at 500°C with further transformation to LaCrO3 orthorhombic phase during annealing at 700°C. A self-organized dendritic structure was reported as a result of the perovskite-phase formation. Although formation of various oxides, such as Fe2O3 and Fe3O4, was observed during the annealing of uncoated SS 446 in air, the coating of SS 446 surface with LaCrO3 film prevented formation of various oxide phases at the interconnect surface. The structural characterization of the films and SS 446 surfaces was accomplished using scanning electron microscopy with energy-dispersive X-ray analysis, X-ray diffractometry, micro-Raman spectroscopy, and nanoindentation.

Notizen: The density, surface tension, and viscosity of the melts from the PbO-B2O3-SiO2 system have been measured at temperatures in the range 1073–1473 K. The effect of composition on these properties was also investigated. The density of the melt was found to increase linearly with increasing PbO content. Molar volume was derived from the density data, and its deviation from the additivity of partial molar volumes was calculated. These deviations in molar volume from those obtained from additivity rules have been used along with the ratio of various coordination numbers of boron (as reported by Bray) to discuss the structure of the melts. The surface tension was found to decrease with decreasing SiO2/B2O3 ratio, and to increase in the range of the PbO content between 30 and 60 mol%, showing a maximum at ∼60 mol% PbO, and then decreased with further additions. This result suggested that the surface tension would be affected primarily by the B2O3 content in the range of the PbO content between 30–60 mol%, and mainly by the PbO content in the range of the PbO content 〉60 mol%, respectively. The viscosity of the melt was found to decrease linearly with increasing PbO content. The results obtained indicate that the increase in viscosity with B2O3 was half that of SiO2 (on a molar basis), and an empirical equation has been proposed for the viscosity as a function of mole fraction.

Notizen: Core/shell structures have been prepared via a mechanofusion system by employing several kinds of spherical polymers as a core material and Al2O3 powder or a mixture of Al2O3 and SiO2 powders as a shell material. The effect of the kind of core polymers on the quality of the resulting hollow alumina microspheres has been discussed on the basis of the thermal decomposition behavior of spherical polymers used as a core material. A large fraction of hollow alumina microspheres reflecting the shape and the particle size distribution of the core polymer could be fabricated after sintering at 1600°3C for 3 h, when highly cross-linked poly(methyl methacrylate) (PMMA) microspheres with a gel fraction of 99.03% were used as a core polymer, and abrupt firing at temperatures higher than 500°3C was adopted to remove the PMMA microspheres. The addition of 5 mass% SiO2 to the Al2O3 shell layer was found to be useful for maintaining the spherical shell structure during the firing process and for fabricating a large fraction of hollow alumina microspheres after the sintering.

Notizen: Well-defined and stoichiometric spherical particles of BaTiO3 of narrow size distribution were produced at 82° and 92°3C by precipitation from chloride solutions in a strong alkaline environment. The size of the particles can be tailored in the range from ≅103 to 70–80 nm by increasing the barium concentration from ≅0.07 to 0.7 mol/L. The particles are composed of tight aggregates resulting from the assembly of several nanocrystals. The size of the nanocrystals decreases from 200–300 to 30–40 nm by increasing reactant concentration. At low barium concentration (≤0.07 mol/L at 82°3C, ≤0.06 mol/L at 92°3C), formation of BaTiO3 is strongly slowed down and nonstoichiometric, Ti-rich powders are produced. Under these conditions, the particles have the tendency to develop a dendritic-like morphology.

Notizen: Crystals of δ-Y2Si2O7 (space group P121/c1) were examined using high-temperature powder X-ray diffractometry to determine their unit-cell dimensions from 296 to 1473 K. The lattice deformation induced by thermal expansion was investigated using matrix algebra analysis to determine the directions and magnitudes of the principal distortions (Λi, i= 1,2, and 3). The directions of Λ1 and Λ3 were defined by the acute angle Λ1c, which linearly decreased from 5(2)° to —5.5(3)° with increased temperature from 504 to 1473 K. The Λ2-axis invariably coincided with the crystallographic b-axis. The magnitudes of Λ1 and Λ2 steadily increased to, respectively, 1.0061(1) and 1.0068(1) during heating to 1473 K, while Λ3 remained almost constant for the entire temperature range. The mean principal distortion, Λm (= (Λ1+Λ2+Λ3)/3), steadily increased to 1.0044(1) with increased temperature to 1473 K. The coefficient of mean linear thermal expansion (α) was derived from the mean principal strain (Λm - 1) as α= (Λm - 1)/ΔT. The temperature dependence was determined to be α= 2.03 times 103+ 1.36(T - 296) (10-9 K-1). Provided that the rule-of-mixtures holds for the Y2Si2O7/Y2SiO5 composites as protective coating on SiC substrates, the volume fractions of 0.72-0.77 (70–75 mass%) would be necessary for the Y2Si2O7 component to match the α-values of both materials.

Notizen: Microcellular silicon oxycarbide open cell ceramic foams were fabricated from a silicone resin. Microcellular foams, with a cell size ranging from ∼1–80 μm, were fabricated using poly(methyl methacrylate) microbeads as sacrificial templates. The compression strength of the foams decreased with increasing cell size.

Notizen: Electroconductive zirconia-toughened mullite (TiN/ZTM) intragranular nanocomposite was fabricated by hot-pressing a powder mixture of nano-sized TiN, ZrO2(2Y), and mullite gel. The material showed a good sinterability and could be highly densified at a low temperature of 1300°3C. Sintering temperature strongly influenced the microstructure and electrical resistivity of the material. The electrical resistivity increased monotonously from 20 Ω-cm to 1.5 times 106°3Cm, as the sintering temperature was increased from 1300° to 1500°3C. TEM results indicated that such a phenomenon could be ascribed to the changes in the microstructure of the material, which led to a decrease in the connectivity of the TiN network in the sample as the sintering temperature was increased.

Notizen: Effects of fluids on material removal rate, chipping damage, and surface roughness in the simulated clinical-dental machining of a dental-type glass ceramic were investigated. Significant differences in removal rate were obtained among the fluids investigated, but only a 4 wt% boric acid solution gave a higher removal rate than conventionally used water. Chipping damage was substantially lower for the boric acid and an oil-emulsion coolant compared with other fluids tested. Surface roughness was independent of the fluids used. The results indicate that improvement can be achieved in both material removal rate and machining damage by the appropriate selection of coolant chemistry.

Notizen: This paper reviews the structures and properties of 10 binary, ternary, and quaternary crystals within the equilibrium phase diagram of the SiO2–Y2O3–Si3N4 system. They are binary compounds SiO2, Y2O3, Si3N4; ternary compounds Si2N2O, Y2Si2O7, and YSi2O5; and quaternary crystals Y2Si3N4O3 (M-melilite), Y4Si2O7N2, (N-YAM), YSiO2N (wallastonite), and Y10(SiO4)6N2 (N-apatite, N-APT). Although the binary compounds are well-known and extensively studied, the ternary and the quaternary crystals are not. Most of the ternary and the quaternary crystals simply have been referenced as secondary phases in the processing of nitrogen ceramics. Their crystal structures are complex and not precisely determined. In the quaternary crystals, there exists O/N disorder in that the exact atomic positions of the anions cannot be uniquely determined. It is envisioned that a variety of cation–anion bonding configurations exist in these complex crystals. The electronic structure and bonding in these crystals are, therefore, of great interest and are indispensable for a fundamental understanding of structural ceramics. We have used ab initio methods to study the structure and bonding properties of these 10 crystals. For crystals with unknown or incomplete structural information, we use an accurate total energy relaxation scheme to obtain the most likely atomic positions. Based on the theoretically modeled structures, the electronic structure and bonding in these crystals are investigated and related to various local cation–anion bonding configurations. These results are presented in the form of atom-resolved partial density of states, Mulliken effective charges, and bond order values. It is shown that Y–O and Y–N bonding are not negligible and should be a part of the discussion of the overall bonding schemes in these crystals. Spectroscopic properties in the form of complex, frequency-dependent dielectric functions, X-ray absorption near-edge structure (XANES), and the electron energy-loss near-edge structure (ELNES) spectra in these crystals also are calculated and compared. These results are discussed in the context of specific bonding configurations between cations (silicon and yttrium) and anions (oxygen and nitrogen) and their implications on intergranular thin films in polycrystalline Si3N4 containing rare-earth elements.

Notizen: Simultaneous synthesis and sintering of hexagonal α-Ti1−x-Alx(N) (0 ≤x≤ 0.08) solid solutions, which contain a small amount of nitrogen, have been performed by a self-propagating high-temperature combustion method under a nitrogen pressure of 4 MPa. Dense materials (∼99% of theoretical) prepared directly from a mixture of elemental (Ti and Al) powders reveal homogeneous microstructure composed of fine grains (12–16 μm). α-Ti1−xAlx(N) (x= 0.02; Ti0.98Al0.02N0.26) exhibits a three-point bending strength σb of 390 MPa, a Vickers hardness Hv of 9.24 GPa, and a fracture toughness KIC of 4.89 MPa·m1/2; their mechanical properties are much improved by doping Al into α-Ti(N), in comparison with those (σb= 245 MPa, Hv= 9.02 GPa, and KIC= 3.77 MPa·m1/2) of α-Ti(N) fabricated under the same conditions.

Notizen: Electrophoretic deposition has been used to synthesize nickel–alumina, functionally graded materials from NiO and alumina suspensions in ethanol. Suspension stability and the kinetics of deposition were studied to determine optimum conditions. Deposition starts with an alumina suspension into which a stream of NiO suspension is injected at various flow rates to obtain the desired profiles. The latter were controlled by varying the deposition current density and component flow rate. The green bodies obtained were sintered in Ar/H2 atmosphere to reduce the NiO to nickel. Various gradation profiles were obtained illustrating the facility of EPD to synthesize continuously graded materials. NiO was used as the precursor for nickel to alleviate settling and rough columnar deposit problems.