bluuebunny/crossref_metadata_2025_split huggingface dataset:
People's education and ‘nation building’ for a New South Africa
Authors: Randall Stephen 
Published: July 2007

My purpose in this article is to restate the continuing relevance of ‘people's education’ as a necessary mobilising dynamic in the project of social emancipation in South Africa today. The notion of ‘salvaging’ the concept of people's education implies that it is in process of being discarded, made over into something new having served its provisional utility. I want to suggest that this is indeed how people's education is now being viewed and that this perception is premature, even inappropriate.
My concerns are threefold: that the transformatory potential of education is being replaced with a ‘skills’ paradigm; that as a consequence of this and other factors, the mobilising element of people's education is in danger of being usurped by its converse — a demobilising or immobilising of the movement; and — related to this latter vis‐a‐vis the requirements of ‘nation‐building’ in a land despoiled by the ravages of apartheid — that this skills‐based notion of national development is misconstrued.
Identification of Consonants and Vowels Presented to Left and Right Ears*
Authors: Shankweiler Donald , Studdert-Kennedy Michael 
Published: July 2007

The results of earlier studies by several authors suggest that speech and nonspeech auditory patterns are processed primarily in different places in the brain and perhaps by different modes. The question arises in studies of speech perception whether all phonetic elements or all features of phonetic elements are processed in the same way. The technique of dichotic presentation was used to examine this question. The present study compared identifications of dichotically presented pairs of synthetic CV syllables and pairs of steady-state vowels. The results show a significant right-ear advantage for CV syllables but not for steady-state vowels. Evidence for analysis by feature in the perception of consonants is discussed.
Improvement, Learning and Retention of Skill at Visual Search
Authors: Rabbitt Patrick , Cumming Geoffry , Vyas Subhash 
Published: July 2007

Three experiments examined factors responsible for improvement in visual search. In Experiment I three groups of subjects were each trained for 3000 trials to search for a particular set of target letters among a particular set of background letters. After intervals of 2, 4, or 6 weeks without further practice they were re-tested, either with the same displays or on new displays which they searched for the same target items among new background items. Negative transfer suggested that memory for specific cue-systems distinguishing target from background letters is retained for as long as 4 weeks. Experiment II examined performance of three very highly practised subjects. After 25 days practice, variations in the size of the target set no longer affected search time. This could not be explained by learning of specific cue systems, since after this amount of practice subjects showed perfect transfer to displays which they searched for the same target items among new background items. Experiment III suggested that practised subjects achieve this high level of competence by learning to make two independent successive decisions, first to locate any member of the target set on the display and next to identify which particular member of the target set has been located.
Zur Kristallzüchtung von Cadmiumsulfid und anderen II—VI‐Verbindungen durch Sublimation in verschiedenen Gasgemischen. I. Chemische Technik zur Gewinnung plättchenförmiger Kristalle des Cadmium‐ und Zinksulfids
Authors: Flögel P. 
Published: July 2007

AbstractZur Gewinnung großer, glatter, plättchenförmiger CdS‐Einkristalle durch Sublimation in verschiedenen Trägergasen wird der Einfluß der Zusammensetzung und der Strömungsgeschwindigkeit des Gases sowie der Temperatur für eine feste experimentelle Anordnung mit gegebener Temperaturverteilung untersucht. Die günstigsten Bereiche für die gegebenen Bedingungen werden abgegrenzt. Einige entsprechende Erfahrungen bei der Sublimation von Zinksulfid werden mitgeteilt.
Electrical structure of the surface of crystalline substrates and its influence on nucleation and growth processes
Authors: Distler G. I. 
Published: July 2007

AbstractThe electrical structure of crystalline substrates has been studied by a new technique based on selective crystallization of decorating material and selective deposition of charged colloidal particles. Silver chloride was found to be a very effective indicator of the electrical relief of crystal surfaces. At early stages of thermal condensation, it crystallizes orientedly on negatively charged regions of the surface and randomly on those charged positively. The method has been applied to the study of triglycine sulphate, LiF, and NaCl crystals. It has been found that the surface of real crystals consists as a rule of positive and negative regions, representing assemblies of charged point defects. Near the cleavage steps certain “dead zones” arise, in which a local compensation of charges takes place. Nucleation occurs mainly at charged point defects and oriented coalescence of islands proceeds with different velocity on surface local regions of different signs. The selectivity of crystallization depends on the relation of the sign and magnitude of potential between different smooth areas of the surfaces of crystalline substrates, on the one hand, and between steps and smooth areas, on the other. The charged point defects and their assemblies which are present on the surface of crystalline substrates induce polarization structures of the electret type in amorphous interfacial layers. These structures are “frozen” in interfacial layers in so stable a manner that the layers turn out to be electrical copies of crystal surfaces, thus reflecting the distribution of potential of the surface. Such copies preserve the “electrical memory” even after they are detached from the surfaces of crystals and can hence be used as active substrates for various heterogeneous processes, in particular, for epitaxy.
Elektronenmikroskopische Untersuchung zur Struktur aufgedampfter Nickel/Chrom‐Schichten
Authors: Schippel E. 
Published: July 2007

AbstractZur elektronenmikroskopischen Untersuchung von auf Glas und keramischen Substraten aufgedampften Ni/Cr‐Schichten wurde Zellin als wasserlösliche Abdruckmatrize verwendet.Zur Erkennung der Schichtstruktur war eine Anätzung der Oberfläche erforderlich, die aufgrund der Passivierung des vorliegenden Schichtmaterials besonders schwierig ist. Die getemperte Legierungsschicht zeigt im Elektronenmikroskop zwei verschiedene Phasen. Die Ni‐reiche, kubisch kristalline Phase mit ausgeprägten idiomorphen Kristallen ist eingelagert in einer “schotterartigen” Cr‐reichen Phase.
Nucleation and crystal growth during sulphidation and oxidation of thin zinc and cadmium films
Authors: Weissmantel Chr. , Hecht G. , Herberger J. , Glauche R. , Wagner I. 
Published: July 2007

AbstractThe kinetics of sulphidation and oxidation of evaporated zinc and cadmium films in pure sulphur vapour and oxygen has been investigated. In the temperature range from 100 to 250°C a rapid gas sorption occurs which may be described by logarithmic expressions such as a = const · log (t – t0). Subsequently a slow reaction is observed the time laws of which can also be represented by logarithmic expressions or by a general power law of the type a = const · t1/n.Electron‐optical and X‐ray studies taken at various stages of the reaction reveal a substantial effect of nucleation and recrystallization processes on the kinetics of layer growth. In detail the following phases of layer growth could be confirmed:

Coating of the metal with a very fine (d ≈ 50 Å) nonoriented layer.
Growth of oriented sulphide or oxide nuclei with diameters of 102–103 Å.
Coalescence of these nuclei and formation of a coherent layer (in the case of CdS and CdO formation of medium‐size oriented crystallites).
Formation of whiskers at slightly higher temperatures.
The results show that nucleation and recrystallization processes strongly affect the kinetics of the formation of surface films on metals. Therefore it can be concluded that it is necessary considerably to modify the theoretical attempts for a quantitative description of layer growth which in most cases are based on a homogeneous layer structure.
Untersuchungen an Systemen aus Salzen und gemischten Lösungsmitteln (XII) Kristallographische Eigenschaften und Zersetzung der Methanolsolvate des MgSO4
Authors: Emons H.‐H. , Seyfarth H.‐H. , Winkler F. 
Published: July 2007

AbstractEs werden die mikroskopischen und IR‐spektroskopischen Eigenschaften von MgSO4 · 2 CH3OH und MgSO4 · 2 CH3OH · 2 H2O, der strukturelle Aufbau und die mikroskopische Verfolgung der thermischen Zersetzung beschrieben sowie einige kinetische Daten mitgeteilt.
Isomorphiebeziehungen bei den Heptahydratsulfaten von einigen zweiwertigen Metallen (Mg2+, Zn2+, Ni2+, Fe2+, Co2+)
Authors: Balarew Chr. , Karaivanova V. , Aslanian S. 
Published: July 2007

AbstractDie Isomorphiebeziehungen bei den Heptahydratsulfaten von Mg2+, Zn2+, Ni2+, Fe2+ und Co2+ werden untersucht. Es wurde festgestellt, daß wenn die Endglieder der betrachteten isomorphen Reihen in gleichen Strukturen kristallisieren, eine lückenlose Reihe der Mischkristalle existiert. Wenn die Endglieder der untersuchten isomorphen Reihen in verschiedenen Strukturen kristallisieren, bildet sich eine Lücke in der Reihe der Mischkristalle. Auf Grund der Kristallfeld‐Theorie wird eine qualitative Erklärung der Unterschiede in den Kristallstrukturen von MgSO4 · 7H2O, ZnSO4 · 7H2O und NiSO4 · 7H2O einerseits und von FeSO4 · 7H2O und CoSO4 · 7H2O anderseits zu geben versucht.
Preparation and X‐ray study of single crystals of solid solutions of γ‐tungsten oxide with germanium and silicon
Authors: Horyń R. 
Published: July 2007

AbstractSingle crystals of two solid solutions of γ‐tungsten oxide with germanium and silicon have been obtained with HCl as transport reagent. Improved values of lattice constants of the γ‐tungsten oxide phase have also been determined.
Studies of Dislocations in Single Crystals of Alumo‐Yttrium Garnet (YAG)
Authors: Arsenev P. A. , Baranov B. A. , Klinchikov S. A. 
Published: July 2007

AbstractStudies of dislocations in single crystals of Aluminium–Yttrium Garnet (YAG). Description is given to the distribution of the average density of dislocations in YAG crystals grown by Czochralski'S method. Effect of various growth factors on the structural perfection of crystals is determined. Certain methods of improving crystal quality are discussed.
The Thermal Etching of GaP
Authors: Kocsis S. , Lendvay E. 
Published: July 2007

AbstractThe thermal decomposition and etching of GaP have been investigated. The {111} GaP surfaces were treated in 10−2—10−5 torr vacuum, and in hydrogen and argon atmosphere, in a temperature range of 900—1300 K. Under the different experimental conditions the etched surfaces show different morphological characteristics and polar properties, from which the suitable range for thermal etching or polishing can be choosen. All experiments show that the evaporation mechanism in vacuum and argon is similar, but in hydrogen the process is different.
Quality evaluation of crystals of mixed oxides of elements of the third group of the periodic system
Authors: Arsenev P. A. , Kamensky E. I. , Potyemkin A. V. 
Published: July 2007

AbstractMathematical modelling methods are considered for the evaluation of perspective use of various materials, dielectric crystals as matrices for laser elements of a certain application. Garnet structure crystals and perovskite structure crystals on the basis of mixed oxides of elements of the Third Group of the Periodic System are considered in detail. The determining influence of crystal‐chemical aspects on the crystal quality and its further application is defined. On the basis of calculations a certain advantage of perovskite structure crystals (aluminate and scandates of rare earths) of garnets during their application as matrices for active elements of optical quantum generators is deduced. A possibility of creating laser elements on the basis of solid solutions of perovskite structure combinations is emphasized.
Mechanische Eigenschaften von Si‐Whiskern aus der Gasphase
Authors: Seidowski E. , Bleeck P. 
Published: July 2007

AbstractEs wird die Zugfestigkeit aus der Gasphase erhaltener und mit Platin dotierter Si‐Whisker untersucht. Der Bruchmechanismus der Whisker wird untersucht, verschiedenen Modelle werden betrachtet und in Abhängigkeit vom Dotierungsgrad ihre Anwendbarkeit diskutiert.
Studies on the microscopic condition of switching channels and on the number of switching cycles of bistable Cu2O devices
Authors: Bäther K.‐H. , Brückner W. 
Published: July 2007

AbstractThe distribution of Cu and Ag concentration in the conductive channel of bistable AgCu2OAg switching devices was investigated with the electron beam micro‐probe. A quasi‐metallic channel centre (Cu content >92 weight‐%) can be distinguished from the remaining channel (Cu deficiency, CuxO, x < 2). A precipitation of electrode material was established in the switching channel. The switching devices are withstanding up to maximum of 104 switching cycles. The reasons for this limited “life” are given.
Oberflächenstörungen und Hohlwachstum bei der Züchtung von β‐Kupferphthalocyanin‐Einkristallen aus der Gasphase
Authors: Hamann C. , Przyborowski F. , Kersten F. 
Published: July 2007

AbstractBei der Züchtung von Kupferphthalocyanin‐Einkristallen aus der Gasphase bilden sich häufig Hohlformen. Diese Erscheinung erschwert bzw. verhindert vorgesehene experimentelle Studien. Untersuchungen zur Überwindung dieser Schwierigkeiten werden beschrieben. Ursachen des Hohlwachstums sind, wie aus den Beobachtungen von Oberflächenstörungen und aus zielgerichteten Züchtungsexperimenten hervorgeht, Wachstumsinstabilitäten, hervorgerufen durch diffusionsbedingte Inhomogenität der Überschreitung über der Wachstumsfront. Durch die Einführung besonderer Verfahrensweisen der Züchtung und Wahl bestimmter Parameter gelang es, volle Kristalle größerer Abmessungen, bis zu einem Millimeter in Querrichtung, zu erhalten. Veröffentlichungen zum Hohlwachstum anderer Substanzen aus der Gasphase werden referiert.
Role of microcrystals in the growth and development of prism faces of cultured quartz (II.) Detached microcrystals
Authors: Joshi M. S. , Kotru P. N. 
Published: July 2007

AbstractResults of microtopographical investigations on prism faces of cultured quartz crystals grown by hydrothermal crystallization techniques, undertaken with a view to determine the influence of microcrystals which get attached to the growing host prism face and then get detached, at some stage of growth, from or still remain attached to the host face, with special reference to the role played by them in the growth and development of host prism faces in particular and the quartz crystals in general, are discussed. The study is an extension of, and obviously to be dealt in continuation with, the earlier one (Part‐I, see JOSHI, KOTRU). Polygonal cavities of various shapes and structures observed on the prism faces are described. Mechanism of formation of the polygonal cavities is explained. Also described are pyramidal depressions, striations, growth hillocks, and etch pits within the cavities on the growing host prism faces. Some of the observed structures within the cavities are attributed to the imprints of the surface structures on the faces of detached microcrystals of quartz. Evidence of growth within the cavities is offered and the implications of such a growth are discussed. Evidence of micro‐etching in the cavities is suggestive of the possibilities of some of the grown cultured quartz crystals to get etched in the autoclave. Two different suggestions are made for the interpretation of the origin of etch pits within the cavities, and there is support for the view that they are as a result of etching, only at a time when the supply quartz gets exhausted, of some of the grown crystals where the growing chamber is the hottest.
Etching of GaP surfaces in Aqua regia and in the Bromine‐methanol‐water system
Authors: Somogyi M. , Schiller V. 
Published: July 2007

AbstractThe etchants aqua regia and bromine in methanol in water and in methanol water mixtures were tested on GaP. Aqua regia acted as nonpreferential etchant on (111) B and on {100} planes, the (111) A plane proved to be more resistent to chemical attack. Indications to the formation of a protecting layer was found. Bromine in methanol proved to be preferential etchant for the {100} plane producing a surface geometry characteristic to kinetically determined processes. Increasing the amount of water the (111) B plane could be dissolved also and etch figures characteristic to nonpreferential dissolution began to appear on the {100} and (111) B planes as well. The preferential effect for the {100} plane seems to be related to the water content of the solvent.
Determination of orientation distribution function from pole figures with reflection coincidences
Authors: Jura J. , Pospiech J. , Mazur J. H. 
Published: July 2007

AbstractThree‐dimensional texture analysis is now an efficient tool for examining polycrystalline materials. Owing to its widespread application, the possibilities and restrictions of determining the orientation distribution function on the basis of various kinds of experimental data should be recognized. With this in mind, the paper considers pole figures featuring reflection coincidence.
Laserverluste in Y3Al5O12‐Kristallen
Authors: Feldner E. , Orlamünder R. 
Published: July 2007

AbstractEs wird der Einfluß der Laserresonatorlänge auf Verlustkoeffizient und Energieoutput von YAG‐Kristallen untersucht. Es zeigt sich, daß durch die Angabe zweier Verlustkoeffizienten und der Änderung des Laserwirkungsgrades, ermittelt bei verschiedenen Resonatorlängen, eine verbesserte Charakterisierung von YAG‐Stäben möglich ist.
Changes of properties of zeolite T crystals during gradual treatment with hydrochloric acid
Authors: Cichocki A. 
Published: July 2007

AbstractThe samples of synthetic zeolite of erionite‐offretite type, modificated with hydrochlorid acid, were tested with the methods of chemical analysis, sorption, X‐ray diffraction and electron microscopy. Theoretically calculated and experimental sorptive capacities of modificated samples were compared. A sharp decrease of zeolite sorptive capacity above 28% of dealumination was observed. This phenomenon was explained by blocking some part of the pores entrances (especially of additional spaces) by the amorphous material.
Crystallographic investigation of single crystals of the mesogen compound 4′‐nitrophenyl‐4‐n‐octyloxybenzoate
Authors: Lemke G. 
Published: July 2007

AbstractX‐ray investigations of single crystals of 4′‐nitrophenyl‐4‐n‐octyloxybenzoate (NPOB) have been performed for the determination of the space group P21/c and the lattice constants (a0 = 16.77 ± 0.02 Å, b0 = 9.207 ± 0.005 Å, c0 = 16.72 ± 0.01 Å, β = 128.0 ± 0.5°). Furthermore powder patterns after Debye‐Scherrer method have been taken to estimate the d‐values together with the indexing. On the basis of small Miller indices the crystal angles yielded a discrepancy between axis ratios determined from optical measurements and X‐ray methods. It can be shown that these differences appear with many molecular crystals.
Erosivität und Mechanolumineszenz
Authors: Sodomka L. 
Published: July 2007

AbstractEine der komplizierten Eigenschaften von Festkörpern ist ihre Erosivität. Eine exakte und einfache Definition ermöglicht es, die Erosivität leicht zu messen. Die Erosion, die die Erosivität verursacht, kann zwei Aspekte haben: 1. technologische, als eine Operation für die Materialbearbeitung; 2. methodische, als eine Methode zur Auswertung der Bearbeitungseigenschaften des Materials. Da bei Erosion zwei interagierende Objekte, Verschleißpartikel und Unterlage der Deformation unterworfen werden, kann in einigen Fällen die Mechanolumineszenz (Tribolumineszenz) bei Erosionsverfahren zur Regulierung, wie auch zur Meßdatenauswertung und zur Erklärung des Erosivitätsmechanismus benutzt werden.
Temperature dependence of doping element incorporation with the chemical vapour deposition of epitaxial silicon (IV). Incorporation of phosphorus in the Si‐H‐Cl‐lP system
Authors: Kühne H. 
Published: July 2007

AbstractThe lower temperature dependence of the phosphorus incorporation with the use of phosphine together with chlorosilanes (ΔH = −13 to −15 kcal/ mole) instead of silane (ΔH = −43 kcal/mole) is explained by introducing a special incorporation equilibrium of phosphine bound to the silicon surface. The source materials phosphorus trichloride and phosphorus pentachloride may be incorporated with this equilibrium.
Interaction between an edge dislocation and a surface‐near precipitate
Authors: Michel B. 
Published: July 2007

AbstractThe paper deals with the influence of the surface of a solid on the elastic interaction energy between an edge dislocation and volume defects such as precipitations. The interaction with point defects is also considered. Analytic expressions for the interaction energy are derived due to the size effect between defect and matrix. An approximation formula for the binding energy between an edge dislocation and a spherical point defect near the surface is presented.
Collinearity and forecasting
Authors: Belsley David A. 
Published: July 2007

AbstractOld saw: Collinearity will not harm forecasts as long as it continues into the forecast period. If, however, collinearity is unlikely to continue but has already harmed estimation, then corrective action (introduction of prior information) to improve estimates should improve forecasts. This paper marshals the diagnostic information needed to assess collinearity's continuance and, when required, to direct meaningful corrective action. The process is illustrated by an example involving forecasts using energy prices.
A preference‐based method for forecast combination
Authors: Wall Kent D. , Correia Charles 
Published: July 2007

AbstractDeterming the best combination of competing forecasts is a problem that has been approached primarily from a statistical viewpoint. An alternative method is presented which is based on two behavioral considerations. First, the major consumers of forecasts, decision makers and managers exhibit a form of risk/regret whereby they assign different costs to different types of forecast error and prefer forecasts that are biased in favour of avoiding ‘high‐cost’ errors. Second, the models from which forecasts are obtained are more often employed in a multi‐step prediction mode even though their parameters have been chosen to minimize only one‐step prediction error variance. The first consideration leads us to a finite state representation of error‐type propagation. Then this is used in concert with the second consideration to formulate a quadratic program whose solution yields the error‐type distribution most preferred by the decision maker. Finally, this vital information permits us to determine the optimal forecast combination. We illustrate the resulting methodology using several time series from the compilation of 1001 series used in Makridakis et al. (1982) and from the NBER forecast databank compiled by Zarnowitz (1984).