bluuebunny/crossref_metadata_2025 huggingface dataset:
Cartographic ideals and geopolitical realities: international maps of the world from the 1890s to the present
Authors: Pearson Alastair , Taylor D. R. Fraser , Kline Karen D. , Heffernan Michael
Published: June 2006

This paper charts the attempts to construct an international map of the world using a standard projection and common conventions and symbols. The first part of the paper discusses the original incarnation of this idea, the International (1:1 Million) Map of the World (IMW), initially proposed by the German geographer Albrecht Penck in the early 1890s. The IMW was designed to challenge the idea that cartography was an inherently national science undertaken by, and for, specific nation states. Despite endless negotiations, delays and compromises, two world wars and the withdrawal of American support, the IMW project continued through the early and middle decades of the twentieth century, initially at the British Ordnance Survey and subsequently at the United Nations, only to fizzle out in the 1970s. The second part of the paper examines the Global Mapping Project (GMP), the latest manifestation of the same idea. Global Map, the first version of which was released in 2000, is an attempt to construct a single world map for the digital age. Like the IMW before it, Global Map is designed to facilitate a common, trans‐national understanding of global problems. However, the technical, institutional and application challenges facing the GMP are different from those that confronted the IMW. Whereas the primary purpose of the IMW was never consistently defined, Global Map has a clearer environmental and educational objective. But if Global Map is to become an effective tool for sustainable environmental management and development, its advocates will need to learn the lessons of the IMW's failure and secure renewed international commitment to the value of international mapping.
Requiem or rebirth? Internal labour markets and labour market restructuring in the Kitchener and Sault Ste. Marie regions
Authors: Rutherford Tod D.
Published: June 2006

Since the 1980s, social scientists and economic geographers have stressed that ‘standard’ forms of employment and internal labour markets (ILMs) which characterized Fordism have declined and have been displaced by post‐Fordist non‐standard and contingent employment arrangements. However, some researchers are critical of the assumptions of a universal decline in ILMs and stress that although ILMs have been significantly restructured, they remain an important part of firm employment strategies. On the basis of a postal survey and interviews conducted with ninety firms and institutions in Kitchener‐Waterloo and Sault Ste. Marie, Ontario, in 1995–1996, I assess the role of ILMs. Although shifts towards non‐standard arrangements are evident, employers are clearly aware of the need to maintain if not develop ILM structures. Finally, I argue that geographers need to reconceptualize the relationships between ILMs and external labour markets (ELMs) as integrated phenomena. Thus firms do not use contingent or ELMs and ILMs in exclusion to each other but as part of a continuum of strategies leading to increased blurring of the ILM and ELMs.
Effects of residential exposure to steel mills and coking works on birth weight and preterm births among residents of Sydney, Nova Scotia
Authors: Burra Tara A. , Elliott Susan J. , Eyles John D. , Kanaroglou Pavlos S. , Wainman Bruce C. , Muggah Henry
Published: June 2006

The Sydney Tar Ponds in Sydney, Nova Scotia, Canada, have been referred to as the most contaminated industrial site in the country. Area residents, aware of the contamination for close to 25 years, are very concerned about their health: past, present and future. In particular, they are concerned about cancer; this is followed closely by reproductive health concerns. The objective of this study was to assess the prevalence and determinants of birth weight and preterm birth among residents living in proximity to an industrial site contaminated with a mix of industrial wastes arising from a former steel mill and coking works (the Tar Ponds) in Sydney, Nova Scotia, Canada. A telephone survey was administered to 500 randomly selected women living in proximity to the site to document reproductive histories. The respondents reported 904 live birth pregnancies occurring in Sydney. The mean birth weight reported for live birth pregnancies was 3,391 g (standard deviation: 570). The reported prevalence of preterm births was 7 percent. Linear regression analyses showed a reduction in birth weight of approximately 85 g among residents in a zone estimated to have higher levels of deposition of airborne effluent from the site. Multivariate logistic regression analyses showed a decrease in the risk of preterm birth as residential distance from the site increased (odds ratio 0.65, 95 percent confidence interval 0.42, 0.98). These data suggest that community exposure to industrial contaminants had some, but little, impact on reported birth weights in this sample of respondents. The apparent increase in risk for preterm births suggests further investigation may be warranted, particularly in light of community concerns. Follow‐up investigations using validated birth records and more sensitive measures of environmental exposure could be used to confirm the findings and further explore the intra‐urban variation in health outcomes. These findings underscore the importance of ongoing clean‐up efforts in Sydney.
Localized cutaneous polyvinylpyrrolidone storage disease mimicking cheilitis granulomatosa
Authors: Chi Ching‐Chi , Wang Shu‐Hui , Kuo Tseng‐tong
Published: June 2006

Polyvinylpyrrolidone (PVP), a polymer of the monomer N‐vinylpyrrolidone with various molecular weights, was originally developed as a plasma expander. Currently, it is widely used in hair sprays, skin care products, fruit juices, and as a retarding agent in drugs such as procaine and hormones. PVP polymers with a molecular weight greater than 20,000 cannot be excreted by the kidneys and therefore are phagocytosed and permanently stored in the reticular endothelial system, leading to the so‐called PVP storage disease. We report a case of localized cutaneous PVP storage disease presenting with persistent upper lip swelling and mimicking cheilitis granulomatosa, which has never been reported before.
The protean spectrum of non‐Hodgkin lymphomas with prominent involvement of subcutaneous fat
Authors: Massone Cesare , Lozzi Gian Piero , Egberts Friederike , Fink‐Puches Regina , Cota Carlo , Kerl Helmut , Cerroni Lorenzo
Published: June 2006

Background:  Subcutaneous T‐cell lymphoma (STCL) represents a controversial entity and a confused concept in the field of cutaneous T‐cell lymphomas (CTCLs). Recently, α/β+/CD8+ STCL has been recognized by the new World Health Organization (WHO)–European Organization for Research and Treatment of Cancer (EORTC) classification of primary cutaneous lymphomas as a distinct entity in the group of CTCLs.

Observations:  We reviewed a series of 53 biopsies from 26 patients (F : M = 19:7; median age: 48; range 18–87) of cutaneous B‐ and T‐cell lymphomas characterized by prominent involvement of the subcutaneous tissue. We could classify our cases according to the following seven categories – (i) STCL: n = 16; (ii) extranodal NK/T‐cell lymphoma, nasal type: n = 2; (iii) cutaneous γ/δ T‐cell lymphoma: n = 2; (iv) anaplastic CD30+ large T‐cell lymphoma: n = 1; (v) diffuse large B‐cell lymphoma, secondary cutaneous: n = 3; (vi) lymphoplasmacytic lymphoma, secondary cutaneous: n = 1; (vii) specific cutaneous manifestations of myelogenous leukemia: n = 1.

Conclusions:  We demonstrated the protean nature of lymphomas with prominent involvement of the subcutaneous fat tissues. The term STCL should be restricted to a homogeneous group of cases characterized morphologically by an exclusive involvement of subcutaneous tissues, immunohistochemically by a T‐cytotoxic α/β phenotype, and biologically by a relatively good prognosis.
How does acantholysis occur in pemphigus vulgaris: a critical review
Authors: Lanza Alessandro , Cirillo Nicola , Femiano Felice , Gombos Fernando
Published: June 2006

Background: Pemphigus vulgaris is a life‐threatening autoimmune blistering disease targeting skin and mucous membranes, characterized by disruption of keratinocytes' adhesion termed acantholysis. Today multiple classes of targets are considered to play a role in the genesis of the acantholysis; of these, the classical pemphigus antigens, desmosomal cadherins (desmoglein 1 and 3) are the best characterized and considered as the most important. Additional antigens include the novel epithelial acetylcholine receptors (α9 and pemphaxin). Thus, acantholysis in pemphigus seems to result from a cooperative action of antibodies to different keratinocyte self‐antigens, but the mechanisms by which epithelial cleft occurs are not yet clearly understood. In fact, the binding of the autoantibodies to these targets generates a plethora of biological effects due, on one hand, to their direct interference with adhesive function and, on the other, to more complex events involving intracellular pathways that modify proteases activity or calcium metabolism, leading to loss of cell–cell adhesion.
Life cycle, growth and diet of Balston's pygmy perch in its natural habitat of acidic pools in south‐western Australia
Authors: Morgan D. L. , Gill H. S. , Potter I. C.
Published: June 2006

Nannatherina balstoni is found in a few acidic pools (pH 3.9–6.0) in the extreme south‐western corner of Australia. Although many of these pools become dry during summer and early autumn, they are recolonized by fish from nearby pools that overflow during winter floods. N. balstoni spawns at the end of its first year of life, when, on average, the males and females have reached 60 and 63 mm t.l., respectively, and then usually die within the next few months. The largest fish, which was one of only three in its third year of life, measured 90 mm and weighed 7.3 g. The von Bertalanffy growth curve parameters for L0, K and t0 were 71.2 mm, 1.69 and – 0.078 for males and 82.6 mm, 1.31 and – 0.095 for females. Fecundity ranged from 550 to 1600. N. balstoni. spawns during the middle of winter, after heavy flooding and when water temperatures are at, or close to, their annual minima. This enables the larvae and young juveniles to capitalize on those aquatic organisms, especially Cladocera, which are very abundant amongst the flooded riparian vegetation that surrounds the pools in winter and spring. Hence, the fish grow rapidly and attain an appreciable size before summer, when the increases that occur in the densities of the larger carnivorous fish species, as a result of marked declines in water levels, increases the chances of predation. By spring, when most N. balstoni exceed 25 mm t.l., the diet changes markedly to one that consists almost exclusively of terrestrial fauna. In contrast, three of the six co‐occurring native species of teleost feed on aquatic and terrestrial fauna throughout the year, while a further two feed only within the water column and the sixth feeds on benthic invertebrates. The pronounced shift in diet exhibited by N. balstoni as it increases in size, allied to dietary differences amongst the other six co‐occurring species, reduces any potential for interspecific competition for food resources during the summer and autumn, when such resources are declining.
Diel vertical and offshore‐inshore movements of anchovies off the central Baja California coast
Authors: Robinson C. J. , Arenas F. V. , Gomez G. J.
Published: June 2006

During the night anchovies were observed in the deep offshore oceanic and intermediate slope zones off the Baja California coast, Mexico, in high abundance. Anchovies moved towards the shallow inshore neritic zone in low density groups, returning at dawn to deeper depth strata. During the day, abundances were reduced drastically and those observed were forming compact and discrete schools at deeper depth strata. Anchovy and euphausiid abundance, as recorded by the echosounder, Were positively correlated.
Natural variation in elemental composition of sagittae from red drum
Authors: Fuiman L. A. , Hoff G. R.
Published: June 2006

Concentrations of calcium, strontium, sodium, and potassium were measured along chronological transects of sectioned sagittae from adult red drum (Sciaenops ocellatus), using a wavelength‐dispersive electron microprobe. Coarse sampling involved triplicate measurements at the centre of each opaque (winter) and translucent (summer) zone. Fine sampling was performed in duplicate at equidistant points (15 μm apart) spanning four opaque zones (3 years of life). Concentrations of strontium generally increased with distance from the core (age). Other elements showed no consistent long‐term trends. Sodium and potassium showed consistent differences between winter and summer otolith zones for ages 6 to 15, but calcium and strontium did not show this seasonal difference. Sampling through these zones on a finer spatial scale confirmed the winter/summer differences as cyclic trends. There was general concordance between annual variation in sodium and potassium concentrations in otoliths and concurrent trends in sea temperature, but significant departures in agreement suggested that temperature was not the immediate determinant of sodium and potassium incorporation. It is suggested that the roughly seasonal patterns of variation in otolith sodium and potassium concentrations may be a result of reproductive activity.
Electrophoretic changes in olfactory system proteins in masu salmon during parr‐smolt transformation
Authors: Shimizu M. , Ueda H. , Kawamura H. , Shimazaki K. , Yamauchi K.
Published: June 2006

Changes in cytosolic proteins of the olfactory system (olfactory epithelium, olfactory nerve and olfactory bulb) and the telencephalon of masu salmon Oncorhynchus masou were analysed by two‐dimensional polyacrylamide gel electrophoresis during parr‐smolt transformation; parr, pre‐smolt and full‐smolt stages. In the olfactory system, several protein spots appeared and disappeared in the course of smolting. One protein spot in particular with an estimated molecular weight of 27 kDa and isoelectric point of 5.6 (M27) disappeared in common with the olfactory system during smolting. The disappearance of M27 was also observed in the telencephalon. These proteins, which appeared and disappeared, may reflect the changes in olfactory function during smolting. Simultaneously, the present study confirmed a salmonid olfactory specific protein of 24 kDa (N24), which existed in the olfactory system but not in the telencephalon, as a single neutral protein spot in masu salmon.
Female 15‐spined sticklebacks detect males with empty nests by non‐visual cues
Authors: ÖStlund Sara
Published: June 2006

Reproductive female 15‐spined sticklebacks Spinachia spinachia chose water flowing from an unmated nesting male rather than water flowing from no male. Since the female could see neither the male nor his nest, this result suggests that she received non‐visual signals.
ZIRCONIUM OXIDE AND THORIUM OXIDE IN CERAMICS*
Authors: Kreidl Norbert J.
Published: June 2006

The properties of the most important zirconium compounds are correlated to the main ceramic applications of these compounds, namely, refractories, ceramic bodies, binders, cements, glazes, glasses, and enamels. A brief survey of the information available on the systems MgO‐ZrO2, TiO2‐ZrO2, SiO2‐Na2O‐ZrO2, and several other systems is included. The more specific ceramic properties are summarized in short descriptions of the applications to each single ceramic field. The ceramic uses of thorium oxide are listed.
VARIABLE FACTORS IN ACCELERATED AUTOCLAVE CHEMICAL DURABILITY TESTS*
Authors: OWENS J. S. , EMANUEL E. C.
Published: June 2006

An investigation was conducted of certain factors which influence the reproducibility of autoclave chemical durability tests. These factors include the method of preparation and the purity of the water used, the rinsing procedure, the volume of solution used, and variations in the test temperature and in the duration of the different periods of the heat cycle. The effect of the internal area of the container on the test results was determined, and suggestions are presented for increasing the reliability of the tests.
The Binary System Anorthite (CaAl2Si2O8)—Åkermanite (Ca2MgSi2O7)
Authors: de WYS E. CHRISTIAAN , FOSTER WILFRID R.
Published: June 2006

A study of the equilibrium relations in the system anorthite‐åkermanite has been made as a part of an investigation of the ternary system diopside‐anorthite‐åkermanite. The technique employed was the well‐known quenching method. The liquidus relations indicate that anorthite and åkermanite form a simple binary system, with a eutectic located at a composition 46 anorthite, 54 åkermanite (by weight) and at a temperature of 1234°± 2°C. There is strong reason to believe that pure åkermanite, rather than an aluminous melilite, crystallizes with anorthite from intermediate compositions. No evidence to support the alleged decomposition of åkermanite at or below 1325°C. was obtained, since åkermanite gave no indication of instability in the liquidus range of temperatures. The study sheds no light on the relations between anorthite and its hexagonal and orthorhombic polymorphs.
Physical Properties of an Illitic Clay Due to Specific Base‐Exchange Cations
Authors: ESCHENBURG R. L. , STONE R. L. , WEISS E. J.
Published: June 2006

An illitic clay from Grundy County, Illinois, was fractionated at 5μ. The base‐exchange cations of the < 5μ fraction were exchanged for Ca++, Mg++, Na+, and NH4+ cations to study the changes in physical properties due to specific base‐exchange cations. Studies on water of hydration, bulk density of dry‐pressed clay, viscosity, and fired properties showed that the base‐exchange cation had a definite effect on the physical properties of the clays studied.
Strength and Static Fatigue of Abraded Glass Under Controlled Ambient Conditions: II, Effect of Various Abrasions and the Universal Fatigue Curve
Authors: MOULD R. E. , SOUTHWICK R. D.
Published: June 2006

A controlled grit blast was found to be a reproducible method of producing standardized damage to a glass surface. The effects of grit size, blast pressure, and amount of grit on the strength of the resulting specimens are reported. Static fatigue curves (strength vs. load duration) were obtained for specimens immersed in room‐temperature distilled water and in liquid nitrogen (77°K.) after the specimens had been subjected to various abrasion treatments. The low‐temperature strength was independent of load duration, and for surface damage of simple geometry it was inversely proportional to the square root of the initial crack depth, consistent with the Griffith theory. Abrasions of different geometry produced differing static fatigue curves at room temperature, and in one case curves actually crossed. If, however, the strength values for each abrasion were divided by the low‐temperature strength for that abrasion and plotted vs. a reduced time coordinate, all the data could be fitted to a single “universal fatigue curve.” This analysis led to a clear distinction between “linear” and “point” flaws, the former being flaws (such as emery scratches) which have an extension in a direction perpendicular to the applied stress and the latter being of a more localized character. Linear flaws fatigue more rapidly than point flaws by a factor of fifty and for each type of damage the fatigue rate is inversely proportional to the exponential of the initial flaw depth. A detailed analysis of the data in terms of several static fatigue theories from the literature shows that none of them provides a complete and adequate explanation of these results.
Mixing and Flow in Glass Tanks
Authors: COOPER ALFRED R.
Published: June 2006

Mixing influences that are effective during the flow of glass through continuous tanks are classified. Common experimental techniques for evaluating these influences are compared. A multi cell model is used to describe flow behavior in the absence of miring from transfer flow. Laminar transfer flow in a glass tank is evaluated by considering flow through an open channel with a vertical viscosity gradient. Recently published results describing flow through a container glass tank at relatively high pulls are best explained by secondary flows modifying the mixing effects from the variable velocity of laminar transfer flow through the tank.
High‐Temperature Centrifuge for Fused Salt Studies: The Invariant Point Between LiF and Li2BeF4
Authors: WITTENBERG LAYTON J.
Published: June 2006

A high‐temperature centrifugal‐filtration apparatus is described for separating the liquid phase from the solid phase in a fused salt system. The filtrate can be observed as it is obtained while the sample is maintained in a controlled atmosphere. The application of this apparatus to a phase rule study is demonstrated by locating the invariant point between the compounds LiF and Li2BeF4 in the binary system LiF‐BeF2 at 66.7 ± 0.8 mole % lithium fluoride and 456°± 2°C.
Fusion of Quartz and Cristobalite
Authors: MACKENZIE J. D.
Published: June 2006

The melting point of quartz is established to be below 1450°C. and possibly above 1400°C. The product of fusion is a liquid of high viscosity which undergoes slow transformation to give the commonly encountered vitreous silica. At temperatures between 1450deg; and 1700°C., both cristobalite and glass are formed when quartz is heated in air for periods in excess of 15 minutes. The quartz‐cristobalite transformation is sensitive to the ambient atmosphere. After heating to temperatures above 1730°C., inhomogeneities are still present in both fused quartz and fused cristobalite in the form of unmelted microcrystals. Their presence is indicated by X‐ray diffraction, metallographic, infrared, and hardness measurements.
Initial Sintering Kinetics of Beryllium Oxide
Authors: AITKEN E. A.
Published: June 2006

The initial sintering kinetics of beryllium oxide are examined, including the effects of calcining temperature, purity, and water‐vapor content of the sintering atmosphere. Sintering occurs by a diffusion mechanism in dry‐air atmospheres. Small additions of MgO to BeO increase the sintering rate markedly. The diffusion constant calculated from sintering data for pure BeO is three orders of magnitude lower than the measured diffusion of Be in BeO. Water vapor in the sintering atmosphere slows the shrinkage rate of pure BeO.
Activation Energy for Diffusion of 133 Xe Through MgO‐Ni Cermet Compacts
Authors: MOODY W. E. , WHITEHEAD W. D. , KRIEGEL W. W.
Published: June 2006

The 133 Xe was produced by irradiation of UO2 which formed the central or core portion of small disks made from a 66% Ni and 34% MgO cermet material. Diffusion rates through this material were determined in the temperature range 800° to 1100°C. The activation energy for diffusion was determined to be 4.4 e.v. with the diffusion coefficient given by the equation D= 1.85 × 107× sq. cm. per second. The mechanism of diffusion appeared to be of the atom‐vacancy interchange type.
Internal Friction of Simple Alkali Silicate Glasses Containing Alkaline‐Earth Oxides: I, Experimental Results
Authors: RYDER ROBERT J. , RINDONE GUY E.
Published: June 2006

The internal friction of simple alkali silicate glasses to which systematic alkaline‐earth oxide additions were made was investigated. These additions produced two significant results: (1) The two peaks previously reported in alkali silicate glasses were shifted to higher temperatures and decreased in height and (2) a third peak was found in some glasses which became more pronounced with increasing alkaline‐earth oxide content. Internal friction measurements of alkali‐free silicate and phosphate glasses also are described. In these glasses, peaks were present which closely resembled those found in glasses containing alkali.
Crystallization of Silica on Polished Glass Surfaces
Authors: de la CIERVA PIEDAD , de ANDRÉS FRANCISCA
Published: June 2006

Polished surfaces of different optical glasses leached with diluted nitric acid exhibited (1) fine lines showing against the uniform background of a thin colored film, (2) macroscopic cracking with or without the production of flakes, (3) holes or grooves of Werent forms and sizes, and (4) numerous crystals of different forms of silica on the inside of lines and grooves and spread over the glass surface. The interpretation of such observations may help in the understanding of the nature of polished glass surfaces.
Colorimetric Determination of Boron in Porcelain Enamel Frits
Authors: MclNTOSH JOHN J. , COX JOHN E.
Published: June 2006

A procedure is presented for the modification of the current method of developing the boron‐curcumin color complex for a quantitative determination of boron in glass. Instead of evaporating an aliquot of the solution to be tested and baking the residue at 55°± 3°C. for a specified time with curcumin indicator solution, the color complex is developed by dissolving a measured volume of test solution in glacial acetic acid with sulfuric acid.
Dysprosium Oxide Ceramics
Authors: PLOETZ G. I. , MUCCIGROSSO A. I. , OSIKA L. M. , JACOBY W. R.
Published: June 2006

Ceramic compositions within the systems Dy2O3‐A1203, Dy2O3‐CeO2, Dy203‐Nb205, Dy2O3‐UO2, and Dy203 ‐Zr02 are described. Compound formation was observed in the dysprosia‐alumina and dysprosianiobia systems whereas solid solutions were observed in the other three systems investigated. The properties that are reported include lattice parameters, density, shrinkage, thermal expansion, water‐corrosion resistance, and compound melting points. Dysprosia was found to stabilize zirconia in amounts as low as 10 volume %.
Reaction Kinetics of Porcelain Enamel‐Metal Systems
Authors: SPRIGGS R. M. , FRIEDBERG A. I.
Published: June 2006

The reaction kinetics of the elevated‐temperature fusion reactions between various powdered metals and finely divided sodium borosilicate porcelain enamel frits were studied. The powdered metals employed were nickel, cobalt, iron, and magnesium; the metallic ions were copper, nickel, cobalt, and iron. These reaction studies were made as a function of time, temperature, and concentration of the metallic ion in the frit. Quantitative X‐ray diffraction was used to determine the amount of metallic ion in each reaction which had been reduced to the metallic state by the added metal. Specific reaction rates were calculated, their temperature dependence was demonstrated by use of the Arrhenius equation, and activation energies were determined from the slope of these curves. The over‐all results were in accordance with the general theory of chemical kinetics, with increases in time, temperature, and metallic‐ion content resulting in increases in the amount of metallic ion reduced, except for those frits containing the iron ion, which, when coupled with cobalt or nickel metal, resulted in probable reduction of the iron ion to a lower valence, but not to the metallic state. Inversions in the order of magnitude of reaction rates for two different metals with the same metallic ion frequently occurred at certain times and temperatures. Reactions such as Fe + COO (NiO) = FeO + Co (Ni), which might take place at an enamel‐metal interface, were strongly favored to the right and very little tendency existed for the reverse to occur.
Constitution of Mixed‐Alkali Phosphate Glasses: I, Constitution of Constant Lithium Variable Sodium‐Potassium Phosphate Glasses
Authors: MURTHY M. KRISHNA , SMITH M. JOYCE , WESTMAN A. E. R.
Published: June 2006

By the use of a mixture of alkali cations, Li, Na, and K, it has been possible to prepare phosphate glasses with higher M2O/P2O5, ratio than was possible by the use of a single alkali cation. Variation of the Na:K ratio over a wide range has no effect on the distribution of polyphosphates in the composition range studied (Li: Na: K = 1:5:1 to 1:1:5). Glasses with × values of 2 or less contain an appreciable amount of orthophosphate ion. The significance of these results is discussed.
Internal Friction of Progressively Crystallized Glasses
Authors: DAY DELBERT E. , RINDONE GUY E.
Published: June 2006

The internal friction of partly crystallized Li2O.‐2.75 SiO2 glass fibers, containing a maximum of 78% lithium disilicate crystals, was measured by the torsion pendulum technique. The following changes in the internal friction were observed with increasing crystallization: (1) The low‐temperature peak, generally attributed to the stress‐induced diffusion of alkali ions, decreased continuously in height and shifted to higher temperatures at the higher crystal contents, (2) the intermediate‐temperature peak decreased continuously in height, and (3) a new relaxation, which first appeared as an inflection in the background of the glasses which had been nucleated at 500° C. without any crystallization, became a well‐defined peak in the partly crystallized fibers. It is suggested that this new relaxation may be an indication of the early stages of nucleation. Possible explanations are given for the high‐temperature relaxation observed in the partly crystallized glasses.
Semiconducting Bodies in the Family of Barium Titanates
Authors: SABURI OSAMU
Published: June 2006

The anomalous resistivity‐temperature characteristics found in semiconducting barium titanates were studied in relation to their composition. The resistivity and impedance characteristics and the crystal structures were investigated for different compositions in the systems (Ba, ‐Sr) (Ti, Sn)O3, (Ba, Ca, Sr)TiO3) (Ba, Pb)TiO3, Ba‐(Ti, Zr)O3, and Ba(Ti, Si)O3 doped with 0.1 mole % of Ce and also in the system (Ba, Mg, Ce) TiO3. Bodies whose compositions were quite different from BaTiO3 could not be semiconducting. The resistivity anomaly in each semiconducting body showed a good correlation with the crystal transition.
Compaction Effects in Glass Fibers
Authors: OTTO WILLIAM H.
Published: June 2006

Glass fibers as commercially produced have physical and mechanical properties which differ from those of the massive form of the same glass. When these fibers are subjected to subsequent heat‐treatments, the values of the measured properties tend to return to those of the massive glass. This phenomenon is called compaction because in the process density increases. The effect of compaction on the physical properties of fibers is discussed and the mechanism of this phenomenon is described briefly.
Hot‐Pressing of Alumina Powders at Low Temperatures
Authors: FELTEN E. J.
Published: June 2006

A better insight into the initial stages of densification during the hot‐pressing of ceramics can be obtained by performing the experiments at low temperatures. The parameters which have been examined are pressure, temperature, and the particle size of the alumina used. The results obtained preclude plastic flow as the predominant mechanism responsible for the large increases in density observed initially. Particle rearrangement by boundary sliding is suggested as the process responsible for the initial increase in compact density.
Microstructural Features and Dislocations on Thermally Etched Sapphire Surfaces
Authors: III HAYNE PALMOUR , DuPLESSIS JOHN J. , KRIEGEL W. WURTH
Published: June 2006

Basal‐, prism‐, and rhombohedral‐plane specimens cut and polished from flame‐grown sapphire boules developed fine surface textures during heat‐treatment in the range 1700° to 1900°C. Microscopic examinations of such surfaces revealed low‐angle grain boundaries, dislocations, and other crystal imperfections. Thermally etched textures apparently were generated by three overlapping processes, namely annealing, etching, and decoration. Thermal etching gave evidence of high‐temperature relaxation of residual strain energy introduced at low temperature (analogous to cold work in metals), including that introduced by fracture, microindentation, and cutting and polishing during surface preparation.
Re‐Examination of the Polymorphism of Dicalcium Silicate
Authors: SMITH DEANE K. , MAJUMDAR A. J. , ORDWAY FRED
Published: June 2006

Samples of Ca2SiO4 were prepared by three different methods. These samples were examined by differential thermal analysis, high‐temperature X‐ray diffraction, and air quenching of pellets. It was found that the β modification, during cooling, converted completely and rapidly to the γ modification and “dusted” only if it had been heated above 1420†± 10† C. If the sample was not heated above this critical temperature, a mixture of the β and γ forms always resulted at room temperature. The addition of 0.5 weight % of CaO, SiO2, Al203, Fe203, or MgO had no effect on the sequence of phases for samples cooled from above the critical temperature. When, however, these same samples were cooled from below 1410†C, the final room‐temperature product was not the same for all samples. On the other hand, the additional 0.5% of Na20, K2O, Cr2O3, or B203 prevented the formation of the β modification regardless of the temperature from which the sample was cooled. The critical heating temperature correlated with the transformation temperature for the α‐α inversion. A theory relating this inversion to the completeness of the β→γ transformation is presented.
Purification, Growth of Single Crystals, and Selected Properties of MgF2
Authors: SCOTT WILLIAM D.
Published: June 2006

A modified Bridgman‐Stockbarger method was used to grow single crystals of MgF2 weighing about 200 g. The purity of the charge material was critical. Purification was achieved by first drying technical‐grade MgF2 and then vaporizing in vacuum. Spectral transmission of the single crystals was measured; in comparison with CaF2, MgF2 was slightly less transparent in the infrared region and had about the same transparency in the ultraviolet region. Modulus‐of‐rupture values were also obtained in several orientations. No plastic flow was observed.
Mechanical Behavior of Sodium Chloride Single Crystals in Flexure
Authors: ROTHWELL W. S. , GREENLER ROBERT G.
Published: June 2006

Evidence is presented to show that plastic deformation of NaCl single crystals by transverse bending arbitrarily takes place in one of two distinct ways which result in quite different stress‐strain behavior. The crystals deform initially by glide either along the {110} slip planes normal to the bending plane or along the {110} planes normal to the neutral plane. A higher rate of work hardening is observed when bending activates slip on the {110} planes normal to the neutral plane. Reliable studies of work hardening and related effects in NaCl single crystals therefore cannot be made in flexure unless careful attention is given to this orientation effect.
Hydrothermal Crystallization of Yttrium‐Iron Garnet on a Seed
Authors: LAUDISE R. A. , KOLB E. D.
Published: June 2006

Yttrium‐iron garnet has been shown to be the stable solid phase, congruently saturating, and not subject to reduction in 50 wt% NaOH between 350° and 425°C at pressures from 200 to 1350 atm. Substantial diffusivity of hydrogen through platinum and gold has been shown to lead to the formation of Fe3O4 in garnet syntheses attempted in platinum or gold capsules where water was the pressure‐transmitting fluid. Yttrium‐iron garnet has been grown on a seed crystal under the following conditions: crystallization temperature, 370°C; dissolving temperature, 420°C; pressure, 200 atm; and solvent, 50 wt% NaOH. The rate of crystallization was 0.08 mm per day in the (111) direction.
Growth Sequence of Gadolinium‐Iron Garnet Crystals in Molten PbO‐B2O3, Solutions
Authors: GIESS EDWARD A.
Published: June 2006

Gadolinium‐iron garnet crystals grown from low‐volatility molten PbO‐B2O3 solutions exhibit macroscopic dendritic growth patterns indicative of their growth sequence and mechanism. There exists a growth anisotropy preferring the [001] direction from which (100) and (010) axial‐plane dendrites radiate. The equilibrium {211} and {110} faces grow from intermediate branch dendrites which are attached to the (100) and (010) dendrites.
Phase Equilibria in the Ternary Fused‐Salt System LiF‐BeF2,‐UF4
Authors: JONES L. V. , ETTER D. E. , HUDGENS C. R. , HUFFMAN A. A. , RHINEHAMMER T. B. , ROGERS N. E. , TUCKER P. A. , WITTENBERG L. J.
Published: June 2006

The phase diagram for the ternary fused‐salt system LiF‐BeF2‐UF4 was determined from 300°C to the liquidus by differential thermal analysis, thermal‐gradient quenching studies, and high‐temperature filtration techniques. The samples prepared by quenching were examined by polarized‐light microscopy and X‐ray diffraction techniques. The experimental methods are described. The primary‐phase fields for the compounds LiF, 7LiF·6UF4, LiF·4UF4, and UF4 covered most of the liquidus surface. Small areas of the liquidus surface were covered by the compounds BeF2, 2LiF·BeF2, and 4LiF·UF4. The compound 4LiF·UF4, which was stable at the binary liquidus temperature, decomposed in the ternary system when the liquidus temperature decreased below 480°C. No ternary compounds or solid solutions were observed. Two ternary eutectics were found. The first, containing 48 mole % LiF, 51.5 mole % BeF2, and 0.5 mole % UF4, melted at 350°C. The second, containing 69.5 mole % LiF, 22.5 mole % BeF2, and 8 mole % UF4, melted at 427°C.
The System SiO2–P2O5
Authors: TIEN T.‐Y. , HUMMEL F. A.
Published: June 2006

Phase relations in the binary system between SiO2‐P2O5 and SiO2 were investigated by the quenching method using sealed platinum tubes to prevent the loss of P2O5. The compound Si02‐P2O5 exists in two forms, the low‐temperature β form inverting sluggishly but reversibly to the high‐temperature β form at 1030°C. The β form melts congruently at 1290°C. The compound 2SiO2‐P2O5 melts incongruently at 1120°C to a silica‐rich liquid and SiOa‐P2O5. In the region between 5 and 25 mole % PO2, reactions were so sluggish that no data could be obtained by quenching.
Growth of Beryllia Single Crystals
Authors: AUSTERMAN STANLEY B.
Published: June 2006

Single crystals of beryllia have been grown by two methods. One method exploits the high‐temperature reversible reaction BeO + H2O.Be(OH)2. The other is a flux method, in which BeO is dissolved and precipitated as single crystals in a lithium molybdate flux. Characteristics and remaining problems of the two methods are discussed, and the crystals produced are described.
Electrical Conduction Anomaly in Samarium‐Doped Barium Titanate
Authors: GOODMAN G.
Published: June 2006

Studies of both single crystals and ceramics of samarium‐doped BaTiO3 having identical compositions show that the positive temperature coefficient (PTC) electrical resistivity anomaly originates at the grain boundaries of the ceramic. The grain‐boundary region is visualized as an electron exhaustion layer, 102 to 104 A thick, of much higher electrical resistivity than the interior of the grain. These findings are compatible with Heywang's barrier layer model, with possible tunneling or electron wave scattering models, and with elements of Saburi's local fields mechanism. Sufficient information to point to any one model is, however, not yet available.
High‐Temperature Thermal Expansion Behavior of Refractory Materials: I, Selected Monocarbides and Binary Carbides
Authors: MICCIOLI BRUNO R. , SHAFFER PETER T. B.
Published: June 2006

An apparatus for absolute thermal expansion measurements has been developed and operated to 2843°C. Thermal expansion characteristics have been measured for niobium carbide, zirconium carbide, tantalum carbide, and the carbide solutions 8TaC·ZrC, 4TaC·ZrC, TaC·ZrC, and TaC·4ZrC. Supporting evidence for a high temperature inversion in the monocarbides of zirconium and tantalum has been observed. Evidence of analogous behavior for other carbides is also reported.
Changes in Relation Between Refractive Index and Young's Modulus as the Result of Successive Heat Treatments
Authors: HAMILTON EDGAR H.
Published: June 2006

The relation between refractive index and elastic modulus is found to be a sensitive indicator of the nucleation and separation of submicroscopic phases in glass. In a study of the changes in properties with heat treatments of a wide variety of glasses containing SOa, B20s, and ZnO as major constituents, it was observed that large decreases in Young's moduli were not accompanied by decreases in refractive indices of the magnitude usually observed. The abnormal changes in properties resulted from a sequence of two heat treatments. The results indicate that during the first heat treatment an immiscible phase is nucleated which, on subsequent heat treatment at a higher temperature, develops into heterogeneous regions producing changes in the relation between the refractive index and the elastic modulus.
Effect of Various Atmospheres on Thermal Con ductance of Refractories
Authors: YOUNG R. C. , HARTWIG F. J. , NORTON C. L.
Published: June 2006

The thermal conductance of insulating firebrick was measured in gas atmospheres other than air. The effect of using insulating firebrick in gases of thermal conductivity higher or lower than that of air was correlated with porosity. Curves are presented that permit direct computation of the thermal conductance of these brick in any gas atmosphere of known thermal conductivity. An equation is given for estimating the thermal conductance of a clay‐based brick using only its porosity and thermal conductance in air.
Thermal Conditioning of Polycrystalline Alumina Ceramics
Authors: INSLEY R. H. , BARCZAK V. J.
Published: June 2006

High‐alumina ceramics, thermally conditioned by reheating to a temperature near the normal maturing temperature and cooling rapidly in forced air, showed significant increases in physical and dielectric strengths over as‐fired specimens. A mechanism for the strength increase is proposed as the prevention of exsolution of components soluble in either a major or minor crystalline phase. Experimental evidence is presented to support this theory. Reheating a polycrystalline, polyphase alumina ceramic relieves internal stresses caused by volume changes associated with exsolution that occurs during slow kiln cooling. Rapid cooling, following the reheating, inhibits exsolution. Spinel cell size and strength of an alumina ceramic containing spinel are correlated. Evidence is presented to show that the dominant thermal‐conditioning mechanism is a volume effect and not the surface effect present in tempered glass.
Hydrothermal Growth of Large Sound Crystals of Zinc Oxide
Authors: LAUDISE R. A. , KOLB E. D. , CAPORASO A. J.
Published: June 2006

Large (10 to 20 g) macroscopically sound ZnO crystals suitable for preliminary transducer and other studies have been grown hydrothermally at rates of from 10 to 15 mils per day. The factors found to be important in achieving good growth were (1) base concentration of growth solution, (2) temperature difference between dissolving and growth regions, (3) presaturation of growth solution, (4) warm‐up procedure, (5) addition of Li+ to the growth solution to suppress dendrite formation, (6) etching to remove seed damage, and (7) nutrient size. Each of the foregoing factors was studied and is discussed.
Properties of Soda Aluminosilicate Glasses IV, Relative Acidities and Some Thermodynamic Properties
Authors: GRAHAM PAUL W. L. , RINDONE GUY E.
Published: June 2006

Electrochemical cells using the oxygen electrode reactions of Förland and Tashiro were constructed from soda aluminosilicate glasses (containing up to 34.8 wt% alumina) and sodium silicate glasses. The emf developed by these cells was measured as a function of temperature. The relative acidities of the glasses, as indicated by the activities of the soda, increased with increasing alumina content, the rate of change increasing when the Al/Na ratio reached 1. The entropy change for the cell reaction went through a maximum. These properties are correlated with the measurements of, and the structural model used in, the previous three parts of this series. Measurements were made to show that the emf values obey an additive relation.
Surface Nucleation and Crystal Orientation in Lithium Silicate Glass Fibers
Authors: BOOTH CHARLES L. , RINDONE GUY E.
Published: June 2006

The effect of inorganic surface treatments on the orientation of lithium disilicate crystals formed in Li2O·2.75SiO2 glass fibers was studied. Glass fibers 0.5 mm and 9μ in diameter were subjected to various surface treatments at room temperature and then heated between 550O and 800°C. It was observed that metal salt solutions applied to the fiber surfaces at room temperature decreased the degree of orientation during heating only if the metal entered the glass and formed nucleation sites within the fibers. Orientation could also be decreased by removing lithium from the glass surfaces. Comparison of the crystallization characteristics of untreated and AgNO3‐treated fibers indicated that the crystallization behavior was controlled by either a growth process or a nucleation process, depending on whether the temperature was below or above 625°, respectively.
Dissolution in Ceramic Systems: I, Molecular Diffusion, Natural Convection, and Forced Convection Studies of Sapphire Dissolution in Calcium Aluminum Silicate
Authors: COOPER A. R. , KINGERY W. D.
Published: June 2006

Measurements of the rate of dissolution of single crystals of sapphire in molten CaO‐A12O3‐SiO2 slag from 1340° to 1550°C under conditions of molecular diffusion, free convection, and forced convection reveal that the rate of dissolution was controlled by transport in the molten silicate. The results were self‐consistent in that the independently calculated apparent binary diffusion coefficient agreed well for all three cases. This binary diffusion coefficient at temperatures above 1450°C coincided remarkably well with that of the tracer diffusion coefficient for the silicon ion. For a number of reasons the significance of this agreement should not be overestimated.
Preparation and Properties of the Boron Phosphides
Authors: PERET JAMES L.
Published: June 2006

The reactions between boron and phosphorus to form the boron phosphides are described. The elements were compacted into pellets and dropped into a preheated reaction zone. The reaction between zinc phosphide and boron also resulted in the formation of the boron phosphides and the complete removal of zinc in the vapor phase. Cubic BP formed initially and decomposed into the rhombohedral B13P2 above 1130°C. The formation of B13P2 by decomposition of BP was rapid and complete at 1600°C. Some properties of BP and B13P2 are summarized. The B13P2 formed by decomposition was a very fine powder and large crystals were grown in metallic melts.
High‐Temperature Transitions in Rare‐Earth Niobates and TantaIates
Authors: STUBIČAN V. S.
Published: June 2006

The high‐temperature transition monoclinic tetragonal in the rare‐earth tantalates and niobates with the formula AB04 was investigated using a high‐temperature X‐ray diffractometer. The transition was reversible and proceeded by a gradual change in symmetry. The temperature of the first appearance of the tetragonal phase increased as the ionic size of the rare‐earth ions decreased and was considerably higher for the rare‐earth tantalates than for the rare‐earth niobates. The mechanism of the change is discussed.