bluuebunny/crossref_metadata_2025 huggingface dataset:
Histiocytic sarcoma with secondary involvement of the skin and expression of CD1a: evidence of indeterminate cell differentiation?
Authors: Frater John L. , Kling Christopher W. , Obadiah Joseph M. , Gardner Laura J. , Grosso Leonard E. , Resh Brooke , Hurley M. Yadira
Published: June 2006

Background:  Histiocytic sarcoma is an exceedingly rare malignant neoplasm composed of cells with a monocyte/macrophage phenotype. In the current nosology of histiocytic neoplasms, histiocytic sarcoma is separate from indeterminate cell histiocytosis, a generally benign disorder characterized by proliferation of a CD1a+ and S‐100+ population of cells lacking Birbeck granules usually limited to the skin.

Methods:  We present a case of histiocytic sarcoma in a 64‐year‐old man presenting as a peritonsillar mass and secondarily involving the skin.

Results:  The malignant cells in the extracutaneous foci of disease expressed macrophage‐associated antigens including S‐100 but were CD1a–. The malignant cells in the skin coexpressed CD1a and S‐100 but lacked ultrastructural features of Langerhans cells, findings indicative of indeterminate cells.

Conclusions:  We discuss the clinical and histopathologic differential diagnosis in association with prior reported cases of histiocytic sarcoma, particularly in cases involving the skin and cases expressing the Langerhans cell‐associated antigen CD1a.
Alternative male reproductive strategies in the peacock blenny
Authors: Ruchon F. , Laugier T. , Quignard J. P.
Published: June 2006

A 4‐year study (1989–1992) of a population of Lipophrys pavo living in a brackish lagoon (Maugio, France) revealed three types of male during the spawning season (April to September): (i) nest‐breeder males which are territorial, and have well‐developed secondary sexual characteristics; (ii) non‐functional males which were abundant only in 1991 when population density was very high and (iii) 1‐year‐old kleptogamic males with small body size which possess neither secondary sexual organs nor a testicular gland, although their testes are functional and hyperdeveloped (up to 10.5% of carcass weight). The percentage of kleptogamic males was fairly stable in the population (from 7.9 to 10.0%) and highly variable in their age class (from 8.5 to 51.3%). It is suggested that kleptogamy is a conditional strategy adopted by smaller males.
Absence of restriction site variation in the mitochondrial ND5 and ND6 genes of Atlantic salmon amplified by the polymerase chain reaction
Authors: O'Connell M. , Skibinski D. O. F. , Beardmore J. A.
Published: June 2006

There was no restriction site variation in Atlantic salmon mitochondrial DNA in an amplified DNA segment beginning in the ND5 gene and terminating in the ND6 gene, although seven haplotypes were observed when the complete molecule was restricted.
Enhanced growth and feeding rate in Atlantic salmon parr occupying a lacustrine habitat in the River Utsjoki, northern Scandinavia
Authors: Erkinaro J. , Shustov Yu. , Niemelä E.
Published: June 2006

The length, weight and stomach fullness index of salmon parr from a lake were higher than in a fluvial habitat on the same river in northern Finland, but no differences in diet composition were detected between the habitats in August. The most important food items of the parr in both habitats were insect pupae and adults. Some lake parr also fed on fish.
The evolving technology of DNA fingerprinting and its application to fisheries and aquaculture
Authors: O'Reilly P. , Wright J. M.
Published: June 2006

In 1985, Alec Jeffreys reported the development of multilocus DNA fingerprinting by Southern blot‐detection of hypervariable minisatellites or variable number of tandem repeat (VNTR) loci. This technology found immediate application to various forensic and scientific problems, including fisheries and aquaculture. By 1989, however, it was recognized by many researchers that inherent problems exist in the application of multilocus fingerprinting to large sample sizes as might occur in fisheries and aquaculture genetic studies. As such, individual VNTRs were cloned for single‐locus DNA fingerprinting. Although single‐locus fingerprinting ameliorates many of the problems associated with multilocus DNA fingerprinting, it suffers from the problem that electrophorectic anomalies of band migration within and between gels necessitates binning of alleles, thus underestimating genetic variability in a given population. Amplification of microsatellite loci by the polymerase chain reaction, however, solved many of the problems of Southern blot‐based DNA fingerprinting. Moreover, microsatellites exhibit attributes that make them particularly suitable as genetic markers for numerous applications in aquaculture and fisheries research: (1) they are abundant in the genome; (2) they display varying levels of polymorphism; (3) alleles exhibit codominant Mendelian inheritance; (4) minute amounts of tissue are required for assay (e.g., dried scales or otoliths); (5) loci are conserved in related species; (6) potential for automated assay. Recent innovations in DNA fingerprinting technology developed over the past 5 years are discussed with special emphasis on microsatellites and their application to fisheries and aquaculture, e.g., behavioural and population genetics of wild species, and selection and breeding programmes for aquaculture broodstock.
Effects of stocking on the genetic diversity of brown trout populations of the Adriatic and Danubian drainages in Switzerland
Authors: Largiadèr C. R. , Scholl A.
Published: June 2006

This study focuses on genetic variation of brown trout Salmo trutta populations of the Adriatic and Danubian drainages in Switzerland. The allozyme and other protein loci data show a major replacement of native stocks from the Adriatic drainages by introduced hatchery trout of Atlantic basin origin. In most samples, diagnostic alleles for the Adriatic form of Salmo trutta f. fario and for the marbled trout Salmo trutta marmoratus are found at very low frequencies (f<0.15). Taking into account previous genetic studies on brown trout of this basin, the Danubian samples are not heavily contaminated with foreign alleles. The results are consistent with records of local stocking activities which account in part for the high introgression rates of Atlantic alleles into local populations of the Adriatic drainages. In addition, introgression is enhanced by a decrease of natural reproduction which is caused by a deterioration of trout habitats through human activities. Furthermore, a third mechanism is proposed that may contribute to the high introgression rates observed: if Atlantic trout are introduced, the reproductive barriers between the two native forms, marbled trout and Adriatic fario respectively, break down. Atlantic trout apparently hybridize with both native forms and generate gene flow between them. In some parts of Adriatic drainages in Switzerland, the patterns of introgression and hybridization are further complicated by introduction of trout from the Danubian system. Alleles of the marbled trout are also found in the samples of the Danubian drainage system. These are due to stocking activities across the watershed.
Aluminum Nitride, a Refractory for Aluminum to 2000°C.
Authors: LONG GEORGE , FOSTER L. M.
Published: June 2006

In commercial practice, where temperatures are low, a number of commercially available materials are satisfactory as a container for molten aluminum. None of these, however, resists attack by aluminum in the temperature range 1800° to 2000°C. An investigation was conducted to find a material completely inert to aluminum at these high temperatures. Aluminum nitride emerged as the material that was inert to aluminum and showed satisfactory properties as a ceramic material. A method of preparing high‐purity AIN by striking a d.‐c. arc between two high‐purity aluminum electrodes in a nitrogen atmosphere is described. A refractory having excellent strength and low porosity was achieved by hydrostatic pressing and firing at high temperatures. The mechanical, electrical, thermal, and chemical properties of the refractory are discussed.
Recrystallization of Cerium Oxide in Porcelain Enamels
Authors: JOHNSON ELWIN L. , FRIEDBERG A. L.
Published: June 2006

The effect of cerium oxide incorporated as the principal opacifying agent in the frit batch on the properties of white cover‐coat porcelain enamels was studied. The effect of several variables on the opacity of the enamel was investigated as a function of firing temperature. Variables studied included (a) the amount of cerium oxide added, (b) the manner in which cerium oxide was incorporated into the enamel, i.e., mill addition, frit addition, or combination of both, (c) composition of the base glass, (d) weight of application, and (e) type of mill addition. Porcelain enamels were produced which had good acid resistance, high gloss, and a reflectance of 80% or more. Mill‐added cerium oxide seemed to be less effective than that which was incorporated in the porcelain enamel as a component of the frit. The spectrophotometric analysis indicated good color stability of cerium oxide enamels.
A New High‐pressure Form of B2O3 and Inferences on Cation Coordination from Infrared Spectroscopy
Authors: DACHILLE FRANK , ROY RUSTUM
Published: June 2006

A new crystalline variety of B2O3 has been prepared at pressures above 22,000 atmospheres and above 400°C. The properties are listed. These moderate pressures also are sufficient to catalyze the crystallization of the more common hexagonal form from B2O3 glass. Pressures, however, of up to 50,000 atmospheres will not convert GeO2 quartz to GeO2 rutile at room temperature. From the infrared absorption patterns of appropriate phases it can be shown that in coesite the tetrahedral coordination of Si4+ (or Be2+ in the model BeF2‐coesite phase) must be unchanged. In the new form of B2O3, however, the coordination number must be substantially different from that in the common hexagonal B2O3.
Fundamentals of Glass‐to‐Metal Bonding: IV, Wettability of Gold and Platinum by Molten Sodium DisiIicate
Authors: VOLPE MILTON L. , FULRATH RICHARD M. , PASK JOSEPH A.
Published: June 2006

Further studies were made on the effect of the nature of the atmosphere on the wetting of gold and platinum by sodium disilicate at 1000°C. The gases were oxygen, nitrogen, carbon dioxide, helium, argon, water vapor, carbon monoxide, hydrogen, and several mixtures of some of these gases. Data reported were obtained in the pressure range 10 ‐5 mm. of Hg to approximately 1 mm. of Hg. A special experimental apparatus was constructed for this purpose. In this pressure range the results showed that the wetting of gold was unaffected by these atmospheres. The platinum‐sodium disilicate contact angle, on the other hand, depended on the nature and pressure of the gas. This angle was affected most by atmospheres of water vapor, carbon monoxide, hydrogen, and oxygen. Water vapor was found to be easily displaced from the metal by oxygen. The results were interpreted on the basis of selective adsorption of the gases at the various metal interfaces and of absorption of oxygen and hydrogen by platinum.
Phase Equilibria in the Systems UF4‐ThF4 and Li F‐UF4‐ThF4
Authors: WEAVER C. F. , THOMA R. E. , INSLEY H. , FRIEDMAN H. A.
Published: June 2006

As part of a study of materials potentially useful as fluid fuels for high‐temperature reactors, equilibrium diagrams for the condensed systems UF4–ThF4 and LiF‐UF4–ThF4 have been determined. Both thermal analysis and quenching techniques were used with phase identification accomplished by microscopic and X‐ray dsraction analyses. A complete series of solid solutions without maximum or minimum is formed by UF4 and ThF4. Within the system LiF‐UF4–ThF, there occur three invariant points and seven primary phases of which four are ternary solid solutions. Optical properties for all the solid solutions, fractionation paths for the ternary solid solutions, and compatibility triangles for the ternary invariant points have been determined.
Influence of Cold‐Reduction Practice on Hydrogen Behavior in Enameling Steels
Authors: HUDSON R. M. , KOTYK M. , STRAGAND G. L.
Published: June 2006

As part of a continuing study intended to relate enameling characteristics to measurable physicochemical properties, experiments were performed in which the behavior of acid‐charged hydrogen in enameling steel and the enamel‐ability of enameling steel were compared for as‐cold‐reduced and normalized lots of steel produced from hot‐rolled specimens given various degrees of cold reduction in the laboratory. Concurrent with increased cold reduction of the steel in the range 0 to about 75% was an increase in hydrogen solubility in the steel and a general decrease both in the intensity of hydrogen‐caused ground‐coat reboiling and in the tendency of the steel to develop delayed defects in direct‐white enamel coats. The influence of cold reduction on hydrogen‐caused defects in enamel coats was diminished by previous normalizing of the cold‐reduced sheet and by the heat‐treatment given the steel during the enamel‐firing process. The influence of cold reduction on hydrogen solubility in steel was only partly overcome by heat‐treatment. For as‐cold‐reduced specimens, increased cold work increased the hydrogen‐desorption rate to a maximum below 20% reduction and a further increase in reduction decreased the de‐sorption rate. For normalized specimens there was a trend for the desorption rate to decrease with an increase in the amount of previous cold reduction of the steel.
Relative Acidities of Glasses Containing Al2O3 and TiO2 as Determined by the Oxygen Electrode
Authors: RINDONE GUY E. , DAY DELBERT E. , CAPORALI RONALD
Published: June 2006

The oxygen electrode has been utilized to determine the relative acidities of sodium and potassium silicate glasses containing alumina and titania in the temperature range 300° to 500° C. The acidity of a potassium or sodium silicate glass is increased by substituting alumina or titania for the soda or potassia. The first additions of alumina tend to increase the acidity of both glasses by forming A1O4 tetrahedra which utilize a portion of the nonbridging oxygen ions to fulfill the coordination requirements. The results indicate further that the Ti4+ ion is in both fourfold and sixfold coordination in the sodium and potassium glasses. Titania increases the acidity when it is in sixfold coordination but tends to decrease it when in fourfold coordination. Both titania and alumina increase the acidity of the potassium glasses more than that of the sodium glasses. This is interpreted on the basis that the oxygen network of the potassium glass, being initially the looser, is tightened more than that of the sodium glass. However, the polymerization of the A1O4 tetrahedra at the higher alumina concentrations causes a loosening of the oxygen network. Previous assumptions that the oxygen electrode reaction is independent of the metal used for the electrodes have been verified by reproducing the data using platinum foil as the electrode material in place of silver foil.
Factorial Design of Experiments in Ceramics, II
Authors: DEAN GEORGE , JONES P. R.
Published: June 2006

This series of experiments illustrates the application of factorial design to the study of the unit operations of a semivitreous body formed by extrusion. The first two experiments were concerned with body preparation and forming; the first identified the factors responsible for variance in the system and the second (the present experiment) was designed to locate the optimum value of these factors that would maximize the fired modulus of rupture more accurately. The factors responsible for the variance were (1) particlesize distribution, (2) water of plasticity, and (3) entrapped air. In the second experiment two factors were used to represent the particle‐size distribution, (1) the Ajax clays which are classified on the basis of amount below 2 p and (2) the kaolin to ball clay ratio. Entrapped air was eliminated in the second experiment. The center of the second experiment as represented by the Ajax clays was moved to the finer sizes. The center as represented by the kaolin to ball clay ratio was moved to the coarser sizes. The levels of the water of plasticity remained at 22 and 28%. It was found that the maximum modulus of rupture fell outside the limits of water of plasticity and the particle‐size distribution as represented by the Ajax clays whereas a ratio of 39.5% Ajax clay to 10.5% ball clay would maximize the fired modulus of rupture.
Nonuniform Toughening of a Glass Disk
Authors: KALMAN P. G.
Published: June 2006

A general theory for the calculation of the stresses in quenched glass was given by the writer in an earlier paper. The method evolved is applied in the present paper to the particular case of a nonuniformly quenched disk. It is shown that it is possible to stipulate initial conditions and the manner of quenching in such a way that the intensity of toughening varies in the disk as a function of the radius without inducing a secondary radial stress system. The quenching parameter C, introduced in another paper by the writer is used in characterizing the manner of thermal solidification of the disk.
Microstructure of Silica in the Presence of Iron Oxide
Authors: VAN VLACK LAWRENCE H.
Published: June 2006

The microstructures that are developed when iron oxide reacts with excess silica at elevated temperatures are described. Compacts of powdered quartz and iron oxide were heated to various temperatures and under selected conditions of oxidation to determine the effect of these parameters on microstructure. The results show that temperature has a small but measurable effect on the geometry of the silica and liquid phases. The oxidation level does not have an effect on the geometry of the phases in this system other than to reduce the liquid content by introducing magnetite as a secondary phase. The strength of silica brick in the presence of high liquid contents probably arises from the interfacial‐energy relations which maintain considerable solid‐to‐solid contact at elevated temperatures.
Phase Diagram of the System BaO‐Fe2O3
Authors: GOTO YASUMASA , TAKADA TOSHIO
Published: June 2006

The phase diagram of the system BaO‐Fe203 was determined by X‐ray diffraction, melting‐point measurement, and microscopic methods. Since the reduction of Fe3+ to Fe2+ was observed by chemical analysis in the samples heated at high temperature, especially in molten samples, the samples were heated at 1 atmosphere pressure of oxygen in the temperature region in which the liquid was in equilibrium; 1 atmosphere pressure of oxygen was su5cient to restrain the reduction of Fe3+. In the temperature region of solid‐solid equilibrium, the dissociation was not observed even when the samples were heated in air. BaO ‐ 6Fe2O3 formed a solid solution with BaO.Fe203. The BaO:Fe203 ratio of the solid solution was BaO.4.5Fe203 at 1350°C. and BaO. 5.0Fe20a at 800°C. The precipitation micro‐structures of each primary solid solution were observed.
Effect of Impurities and Heat‐Treatment on Ductility of MgO
Authors: GORUM A. E. , LUHMAN W. J. , PASK J. A.
Published: June 2006

Stress‐strain curves were obtained in flexure and in tension on single crystals of MgO. A decrease in iron content and high‐temperature heating and rapid cooling caused a decrease in strength and increase in ductility. Heat‐treatment of previously deformed specimens increased their strength. The slip band structures resulting from deformation were brought out by chemical etching, and their significant features are discussed.
Dielectric Properties of Alumina at High Temperatures
Authors: FLORIO JOHN V.
Published: June 2006

The dielectric constant and dissipation factor of both single‐crystal and polycrystalline alumina were measured in air over the frequency range lo2 to 3 × 105 cycles per second, in the temperature interval 900° to 1300° C. The three‐electrode guard‐ring method was used. The observed dielectric losses were due predominately to free‐electron conduction mechanisms. The volume conductivity of single‐crystal and polycrystalline alumina was calculated from the high‐frequency data. The temperature dependences of the volume conductivity for two single crystals of different thicknesses were similar. The large thermal activation energy indicated intrinsic conductivity; the energy band gap of alumina was calculated to be approximately 7.3 electron volts. The bulk conductivities of the polycrystalline alumina were considerably higher than the single‐crystal values, presumably because of impurities in the polycrystalline material. The results were compared with values previously reported in the literature.
Formation and Properties of Low‐Melting Glasses in the Ternary Systems As—TI—S, As‐TI‐Se, and As—Se—S
Authors: FLASCHEN STEWARD S. , PEARSON A. DAVID , NORTHOVER WILLIAM R.
Published: June 2006

Glass formation has been found to be extensive in the systems As‐TI‐S, As‐Tl‐Se, and As‐Se‐S. Glasses in these systems exhibit unique low‐melting properties; some are highly fluid as low as 185OC. The marked effect of thallium in lowering the viscosity of binary As‐S melts was found to be unique among all the metallic additives studied. The glasses are stable, covalent, chemically durable, and dielectric. They exhibit good wetting properties with respect to most metals, and the permeability of the seals formed as well as the volume permeability of the glasses themselves appears to be extremely low. Linear thermal expansion coefficients of some compositions are high, but associated thermal cracking problems are minimized to some extent by the low softening temperatures. The glasses can be evaporated and directly condensed (in uacuo) to form continuous, grain‐free glassy films. The glasses are of considerable interest in the study of the nature of the vitreous state. In addition, their over‐all properties make them potentially useful for hermetic sealing of semiconductor and other moisture‐sensitive electronic components which might be damaged by high‐temperature sealing processes.
Analysis of Boron in Borosilicate Glasses by Neutron Transmission
Authors: SEGATTO PETER R.
Published: June 2006

A rapid method for the determination of boron in borosilicate glasses by neutron transmission has been developed. The glass sample is dissolved in 48% HF, placed in a polyethylene cell which is located near a Ra‐Be neutron source. The neutron source and sample cell are embedded in a parafEn moderator. The attenuation of the neutron flux, which can be related to the boron concentration in the cell, is monitored with a BF3 enriched B10 proportional counter. Boron determinations can be made in approximately 40 minutes with an accuracy of ±%. Owing to the low sensitivity (approximately 1 mg.) the major disadvantage of the method is the large sample size necessary. The method, however, is well suited for use as a quality control procedure.
Production of Hollow Lightweight Aggregate by Controlled Preheating
Authors: STAMBOLIEV HRISTO
Published: June 2006

A study was made of the bloating mechanism in two clays which contained large amounts of organic carbon, alkalis, and sulfates. Controlled preheating of spherical pellets at about 550oto 600° C. for relatively short times caused the loss of organic carbon and other gas‐forming constituents from the outer rim of the specimens. A second flash firing at about 1250oC. produced a partly liquefied rim, which trapped gas formed in the central portion. The pellets thus formed were characterized by a large central cavity and a strong porous wall. Variation of firing times, temperature, pellet sizes, and composition allowed considerable control of the nature of the final bloated pellets. It was concluded that bloating was caused by the formation of SO2and CO. The specific gravity of such pellets was between 0.45 and 0.60. They could be produced in all sizes and fell within the A.S.T.M. specifications C 130‐42 (Lightweight Aggregates for Concrete).
Behavior of Chromite Spinel as Related to Microstructure
Authors: TREFFNER WALTER S.
Published: June 2006

The microstructure of massive, sugary, and mylonitic varieties of raw chrome ores has been examined with the aid of polished sections and the difference in the surface area and homogeneity of the natural chromite spinels has been noted. The behavior of the chromite spinels on oxidation, reduction, and with and without the additions of magnesia is illustrated in a series of photomicrographs; the complex reactions occurring are discussed briefly and their significance in the behavior of chrome ore‐containing refractories in slag‐free environments is indicated. The usefulness of reflected‐light techniques in studying diffusion phenomena is shown for several solid‐state reactions, including the formation of synthetic spinels, artificial modifications of a natural spinel, and iron oxide bursting.
Stability of Inorganic Fluorine‐Bearing Compounds: I, Binary Metallic Fluorides
Authors: DEADMORE D. L. , MACHIN J. S. , ALLEN A. W.
Published: June 2006

Because of the practical importance in connection with the loss of fluorine from slags and enamels, the stabilities of NaF, KF, MgF2, CaF2, and ZnF2 in dry and moist atmospheres at elevated temperatures were studied by following the loss in weight of 0.25‐ to 2.0‐gm. samples. The principal reaction was shown to be hydrolysis of the salts in moist atmospheres. The activation energies for the hydrolysis were calculated. NaF and KF were hydrolyzed little or not at all below 1000°C., MgF2 was hydrolyzed readily in the range 1050° to 1150°C., CaF2 was hydrolyzed slowly in the range 1200° to 1350°C., and ZnF2was completely hydrolyzed in the range 680° to 750°C.
Grain Growth and Phase Transformation of Titanium Oxide During Calcination
Authors: IIDA YOSHIO , OZAKI SHUNRO
Published: June 2006

Additions of NiO, CoO, MnO2, Fe2O3, and CuO promote the anatase‐rutile transformation and grain growth of TiO2. Additions of Na2O and WO3 retard the transformation and have no effect on the grain growth. The addition of MoO3 strongly promotes the grain growth but has only a slight effect on the phase transformation. Both the grain growth and transformation are promoted slightly by Cr2O3. The transformation is significantly affected by the method of preparing TiO2. The grain size of TiO2 heated in H2 exceeds that of TiO2 heated in O2, in air, in argon, and in vacuum. The rate of transformation decreases with an increase in the partial pressure of oxygen of the atmosphere.
Particle Size of Feldspar and Flint as a Factor in Slip Behavior
Authors: PHELPS G. W. , DENNIS JOHN S.
Published: June 2006

Although the greater portion of ground. feldspar and flint particles is in the noncolloidal range, the results of experiments conducted on commercially available flint and feldspars show conclusively that variations in the specific surface of these materials, stemming from differences in particle‐size distribution, can be a major factor in variable slip behavior.
Reaction Studies of Ceramic‐Coated Tungsten
Authors: BERGERON C. G. , TENNERY V. J. , FRIEDBERG A. L.
Published: June 2006

A coating consisting essentially of zircon and glass was fired in vacuum on tungsten wires. Coated wires were tested up to 10 hours at 3000°F. in an air atmosphere. Microstructural and X‐ray diffraction analyses indicated that the coating on the tested specimens consisted of glass and monoclinic zirconia and that certain tungsten oxides were present in the coating. These analyses also indicated that the probable mechanism of degradation in this type of coating may be attributed to the gradual migration of oxygen through the coating, with the resultant formation of tungsten oxides which then migrate to the coating surface and volatilize.
Melting Relations of Magnesium Oxide‐Iron Oxide Mixtures in Air
Authors: PHILLIPS BERT , SÕMIYA SHIGEYUKI , MUAN ARNULF
Published: June 2006

The quenching technique has been used to investigate phase relations in the liquidus temperature region of a part of the system magnesium oxide‐iron oxide. The study concerns primarily the nature of the melting behavior of the spinel phase magnesioferrite, “MgO‐Fe2O3.” This phase is shown to decompose at 1713°± 5°C. to a magnesiowüstite solid solution phase and liquid, under equilibrium conditions in air.
High‐Pressure‐High‐Temperature Polymorphism of the Oxides of Lead
Authors: WHITE W. B. , DACHILLE FRANK , ROY RUSTUM
Published: June 2006

The common oxides of lead, PbO, PbO2, and Pb3O4, were examined at pressures of 0 to 60,000 atmospheres and temperatures of 100° to 600° C. The pressure‐temperature curve for the litharge‐massicot transition was measured, giving a ΔH of transition of 57 cal. per mole. Unusual meta‐stability and inversion characteristics of the massicot phase were examined in detail. PbO2 (rutile) transformed at pressures in excess of 13,000 atmospheres at 300°C. to an ortho‐rhombic form. The univariant equilibrium curve for the transition gave a ΔH of 11 cal. per mole. Pb3O4 underwent a disproportionation reaction yielding PbO and “Pb2O3.” The equilibrium curve for this reaction was measured, and ΔH was determined to be 4500 cal. per mole.
Nucleation and Growth of Sodium Disilicate Crystals in Sodium Disilicate Glass
Authors: SCOTT WILLIAM D. , PASK JOSEPH A.
Published: June 2006

A high‐temperature microscope for use with transmitted or reflected light up to × 400 magnification and up to 1400°C. was constructed. Nucleation and crystal growth in sodium disilicate glass was studied with this microscope. Heterogeneous nucleation occurred at the interface between the glass and the platinum heating element from 450° to 870° C. with a maximum at 600° C. Heterogeneous nucleation also occurred at the glass‐atmosphere interface from 25° to 375° C. as a result of surface reactions with water vapor. No homogeneous nucleation was observed. Linear growth rates of α and β sodium disilicate crystals were measured from 600° to 870° C. in two sodium disilicate glasses. Metastable growth of both α and β was observed, and growth rates of α and β were the same at a given temperature for a given glass. An equation relating fluidity and undercooling to growth rate was applied.
Effect of Boron on Square‐Loop Cadmium Manganese Ferrites
Authors: EICHBAUM B. R.
Published: June 2006

In semiconductor fabrication it is common practice to use a grain‐growth promoter with pure germanium or silicon with very small quantities (parts per million) of a promoting agent (such as boron or phosphorus) to obtain the desired semiconducting properties. Several materials such as antimony, boron, lead, lithium, potassium, and sodium were investigated as possible agents for the promotion of grain growth in cadmium manganese ferrites. It was noted that the characteristics of ferrites could be affected by treating with these agents before sintering. The boron additions to these ferrites accelerated the reaction rates (catalytic action) and affected the characteristics during sintering. The methods of preparation and the observed results are discussed.
Spontaneous Cracking in Unfired Magnesia Compacts Upon Standing in Air
Authors: DAVIES MYRON O. , GRIMES HUBERT H. , MAY CHARLES E.
Published: June 2006

Analytical‐grade magnesium oxide powder without binder was compressed hydrostatically to 50,000 lb. per sq. in. to form compacts. When exposed to moist air immediately after pressing, these compacts developed irregularly shaped cracks. Controlled tests, in which these compacts were exposed for various lengths of time to various atmospheres, indicated that in general water vapor, carbon dioxide, and residual stresses had to be present if cracking was to occur. The probable cause of the cracking was the formation of a less dense and mechanically weak basic carbonate of magnesium at crystallite surface points of high stress concentration which developed during the compacting. The adsorption of dry CO2 at such sites prevented subsequent delayed fracture.
Studies in Lithium Oxide Systems: XI, Li2O–B2O3–P2O5
Authors: TIEN T. Y. , HUMMEL F. A.
Published: June 2006

The glassforming region in the system was roughly outlined and liquidus data were obtained for the three joins LiPO3‐BPO4, Li4P2O7‐BPO4, and Li3PO4‐Li2B4O7. Compatibility relations for the ternary subsystems Li4P2O7‐BPO4‐P2O5 and Li2O‐Li3PO4‐Li2B8O13 were established. Two ternary compounds with the probable compositions 22Li2O ‐ 11B2O3 ‐ 13P2O5 and 2Li2O 3B2O3 P2O5 were detected.
Effect of Additives on Properties of Lead Titanate
Authors: TIEN T.‐Y. , CARLSON W. G.
Published: June 2006

The effect of additives on the properties of lead titanate was investigated. The additives employed were selected on the basis of potential solid solution or liquid formation with PbTiO3 during sintering. Most of these additives aided sintering and produced dense polycrystalline specimens of PbTiO3 with densities in the range 89 to 95% of theoretical. The dielectric constant and dissipation factor were found to vary considerably, depending on the additive employed. Some poled specimens exhibited a piezoelectric coefficient, d33, as high as 130 × 10−12 coulombs per newton with a dielectric constant of about 160 at room temperature. The microstructure of some of the specimens was also studied and a texture similar to that of barium titanate was observed for those specimens which gave the higher piezoelectric response.
Hot‐Pressing Magnesium Fluoride
Authors: BUCKNER DEAN A. , HAFNER HAROLD C. , KREIDL NORBERT J.
Published: June 2006

Hot‐pressing powdered magnesium fluoride resulted in a polycrystalline compact with essentially the density and transmittance of a single crystal. Compacted powdered MgF2 was heated to 650°C and held under a pressure of 30,000 psi for 15 minutes. The starting material had to be free from impurities which would form a second phase, and the presence of water and bound hydroxyl groups had to be minimized. Overheating caused the starting material to resist hot‐pressing. It is postulated that mechanical bulk decrease was followed by plastic deformation during pressing and that both solid and surface diffusion of material took place to complete the coalescence of the grains.
Ceramic Nuclear Fuels in the System UO2‐ZrO2‐CaO
Authors: HANDWERK J. H. , WHITE G. D. , HILL D. C.
Published: June 2006

Potential nuclear fuels in the system UO2‐ZrO2‐CaO were investigated. Cubic fluorite‐type solid solutions, as indicated by X‐ray diffraction patterns, were formed by sintering U3O8‐CaO‐stabilized ZrO2 compacts in either air or hydrogen. A continuous solid solution was found between urania and stabilized zirconia after sintering in hydrogen at 1750°C. Sintering in air produced a limited solid‐solution region in the stabilized zirconia portion of the system at 1450°C. Results on phase identification, oxidation behavior, and water corrosion are presented.
Phase Equilibria in the System NaF‐ThF4‐UF4
Authors: THOMA R. E. , INSLEY HERBERT , HEBERT G. M. , FRIEDMAN H. A. , WEAVER C. F.
Published: June 2006

Phase equilibria in the condensed system NaF‐ThF4‐UF4 were determined by cooling‐curve and thermal‐gradient quenching experiments from the liquidus to ∼450°C. A phase diagram of the ternary system was constructed, showing three singular points and eleven invariant points, including two eutectics, occurring in association with the primary phases of ten solid solutions and two pure solids. The eutectic mixture having the composition 75.5NaF‐10.5ThF4‐14UF4 (mole %) melts at 575°C, the lowest liquidus temperature in the system. Except for NaF, NaF‐ThF4, and ThF4‐UF4 solid solutions, phases crystallizing from molten NaF‐ThF4‐UF4 mixtures are solid solutions formed by interchange of U4+ and Th4+ ions in NaF‐ThF4 and NaF‐UF4 compounds. No ternary compounds were found. Phase diagrams of the systems NaF‐ThF4 and NaF‐UF4, revised in the course of this study to include the newly identified phases, 7NaF.2ThF4 and 7NaF.2UF4, are presented. X‐ray diffraction and optical data are given for the pure crystal phases, 4NaF.ThF4, 7NaF.2ThF4, 7NaF.2UF4, 3NaF.UF4, and for 3NaF.2ThF4‐5NaF.3UF4 solid solutions. The system is unique among the fluoride systems reported in containing so wide a variety of substitutional solid solutions and in containing a continuous solid solution formed of binary compound pairs 3NaF.2ThF4 and 5NaF.3UF4 which are isomorphous but of different stoichiometry.
Aluminum Oxide‐Titanium Oxide Solid Solution
Authors: DEAN McKEE WILLIAM , ALESHIN EUGENE
Published: June 2006

An oxide of titanium, apparently Ti2O3, showed solid solubility in Al2O3 of 1.0, 1.8, and 2.5 mole % at 1400°, 1600°, and 1700°C, respectively, when heated in hydrogen with a dew point of about ‐50°C. At the same temperatures in air, however, no indication of solid solubility (of TiO2, presumably) was found by X‐ray diffraction. It is concluded, therefore, that titania effects densification and grain growth of alumina by grain‐boundary action rather than by a defect mechanism in the corundum lattice resulting from the substitutional solution of Ti4+ ions.
Role of Solute Segregation at Grain Boundaries During Final–Stage Sintering of Alumina
Authors: JORGENSEN P. J. , WESTBROOK J. H.
Published: June 2006

The addition of minor amounts of MgO or NiO to Al2O3 inhibits grain growth during sintering and allows the sintering process to proceed to theoretical density by maintaining a high diffusion flux of vacancies from the pores to the grain boundaries. The inhibition of grain growth is accomplished by the segregation of solute at the grain boundaries, causing a decrease in the grain–boundary mobility. The segregation of MgO or NiO at the grain boundaries can be inferred from the results of the microhardness studies presented and is substantiated by autoradiographic experiments and also by lattice parameter determinations as a function of grain size.
Solubility of Carbon Dioxide and Variation of Oxygen Ion Activity in Soda‐Silica Melts
Authors: PEARCE M. L.
Published: June 2006

The solubility of carbon dioxide in 25, 35, 43, and 56 wt% soda‐silica melts was investigated. Anomalous results obtained by other workers are explained on the basis of the large viscosity and viscosity‐temperature relationships which prevail for high‐silica melts. The results are related to the variation of oxygen ion activity with composition and are examined in the light of the data of other workers and current theories of the structure of molten silicates.
Chemical Mechanisms Contributing to Wear of Single‐Crystal Sapphire on Steel
Authors: BROWN W. R. , EISS N. S. , McADAMS H. T.
Published: June 2006

Chemical mechanisms which could be active in the wear process are reviewed. Identification of mechanisms present in the wear of single‐crystal sapphire spheres on steel has been attempted by examining worn surfaces and wear debris with the electron microscope. The reaction of iron oxide with aluminum oxide is confirmed by electron and X‐ray diffraction of the debris removed from the steel. The variation of instantaneous interface temperatures as detected by radiation pyrometry was correlated with the location of the wear debris on the wear track.
Relation Between Molecular Force Calculations and Observed Strengths of Enamel‐Metal Interfaces
Authors: O'BRIEN WILLIAM J. , RYGE GUNNAR
Published: June 2006

Thermodynamic works of adhesion between a porcelain enamel and gold, platinum, palladium, graphite, and a gold‐base metal alloy were determined from surface‐tension and contact‐angle measurements. Theoretical shear strengths in the order of 80,000 psi were calculated from these data. Mechanical strength tests indicated values, however, of only 3000 to 10,000 psi for these interfaces. Wetting forces were therefore strong enough to account for the observed interface strengths. The strengthening effect of metal oxides on the bond strength is discussed in terms of the polarization and dislocation theories.
Dislocation Structures in Single‐Crystal Al2O3
Authors: STEPHENS D. L. , ALFORD W. J.
Published: June 2006

Chemical polishing and etching techniques were used to reveal the dislocation structures of sapphire and ruby crystals grown by the flame‐fusion and flux techniques. The average density of edge dislocations lying in prism planes was 3.0 × 105 per cm2, which could be changed only slightly by chromium additions and annealing at 2000°C. An average basal dislocation density of 2 × 105 per cm2 decreased 35 to 80% on annealing. Crystal orientation (i.e., angle between the c axis and the growth axis) showed no effect on dislocation density but a pronounced effect on subboundary arrangement and density. The substructure of 0° crystals was more complex than that of 90° crystals; 60° crystals possessed a structure intermediate between 0° and 90°. Principal observations included (1) prismatic and basal slip on all as‐grown crystals; (2) profuse basal slip, readily polygonized on annealing; (3) dislocation densities of flux crystals lower than those of Verneuil crystals; and (4) a rare form of basal twinning, composition plane , on all flux crystals.
Rare‐Earth Niobates and TantaIates of Defect Fluorite‐ and Weberite‐Type Structures
Authors: ROOKSBY H. P. , WHITE E. A. D.
Published: June 2006

By firing 3/1 mixtures of rare‐earth oxide (A23+O3) and niobia or tantala (B26+O5) at high temperatures, compounds of composition A33+‐B5+O7 may be prepared. The crystal structures of such compounds have been examined and two related types have been found. These are identified as a cubic defect fluorite or pyrochlore‐like type and one analogous to orthorhombic weberite. Lanthanum and neodymium oxides form compounds with the orthorhombic structure, whereas with samarium, gadolinium, dysprosium, yttrium, and scandium oxides the compounds are cubic. For a given rare earth the lattice parameters of compounds prepared with either niobia or tantala are substantially the same. The division between the weberite‐type and defect fluorite‐type structures appears to depend primarily on the radius of the rare‐earth cation, the cations of largest radii producing the deformed orthorhombic structure. The results are consistent with suggestions made by Aleshin and Roy in a recent discussion of the crystal chemistry of pyrochlore.
Thermal Conductivity of Uranium Dioxide from ‐57° to 1100°C by a Radial Heat Flow Technique
Authors: GODFREY T. G. , FULKERSON W. , KOLLIE T. G. , MOORE J. P. , McELROY D. L.
Published: June 2006

A radial heat flow technique was used to measure the thermal conductivity, k, of polycrystalline UO2in the range ‐57° to 1100°C. The technique yielded results with a probable accuracy of ±1.5% and a precision of ±0.1% in the range 50° to 1100°C. Meaningful measurements were limited to 1100°C by Pt‐90 Pt10Rh thermocouple instability, although the apparatus was structurally sound to 1400°C. The thermal conductivity data up to 1000°C could be explained on the basis of heat transport by phonons. The thermal resistance, l/k, exhibits a linear temperature dependence from 200° to 100°C, which is expected for an insulator well above the Debye temperature. The slope of the l/k‐temperature plot is 0.0223 cm w−1 which is independent of impurity content and is associated with three phonon umklapp processes. The intercept is sensitive to impurity content as indicated by the fact that it was decreased by a decrease in the oxygen/uranium ratio. Between 1000° and 1100°C, there is a slight departure of l/k from linearity which may be due to the onset of an electronic contribution. Near room temperature, UO2 has a maximum in k which is apparently caused by the rapid decrease in specific heat below this temperature.
Mechanical Failure Phenomena in Pyrolytic Graphite at Room Temperature
Authors: BERRY J. M. , GEBHARDT J. J.
Published: June 2006

The mechanical behavior of pyrolytic graphite was investigated: (1) to develop an understand ing of the phenomena of failure and to apply it to the interpretation of mechanical properties data, and (2) to explore techniques for increasing room temperature strength. Pyrolytic graphite is ex ceedingly anisotropic and brittle. The condi tions of deposition determine the degree of ani sotropy and this, in turn, has a marked effect on the relations among specimen‐test configuration, nominal strength, and fracture mode. Further more, the “notch sensitivity” is orientation de pendent and thus related to the degree of ani sotropy. The mechanical test results and studies of the fracture modes suggest that results from testing conventional laboratory specimens are not necessarily representative of those which would be obtained by testing free‐standing structures.
Reinvestigation of the Phase Diagram for the System Titanium–Oxygen
Authors: WAHLBECK PHILLIP G. , GILLES PAUL W.
Published: June 2006

Samples of the titanium oxides with O/Ti ratios between 0.5 and 1.67 were prepared by heating mixtures of Ti and TiO2 in high vacuum to 1500°C and annealing them in silica ampuls at 900° to 1100°C. Results of chemical and X‐ray analyses are combined with previously published data to form a complete phase diagram. The melting points of Ti2O3 and Ti3O5 were 1839°° 10°C and 1774°° 10°C, respectively.
Effect of Metal Oxide Additions on the High‐Temperature Electrical Conductivity of Alumina
Authors: VERNETTI R. A. , COOK R. L.
Published: June 2006

Several metal oxide additions were made to typical 99 and 96% alumina compositions to study their effect on the electrical conductivity of alumina from 500° to 1400°C. The metal oxide additions investigated were CO2O3, Cr2O3, CuO, Fe2O3, MnO2, NiO, and TiO2. Using a guarded two‐probe technique, dc resistivities were measured on nonporous ceramic specimens. Additions of 0.5 to 2 mole % Co2O3, 2 mole % CuO, 1 mole % Fe2O3, or 2 mole % NiO to either a 96 or a 99% alumina composition increased the electrical resistivity. The addition of 1 mole % Cr2O3 to either a 96 or a 99% alumina showed practically no change in the resistivity. All changes in resistivity seemed to be structure dependent.
Chemical and Mechanical Mechanisms in Wear of Sapphire on Steel
Authors: EISS NORMAN S. , FABINIAK RICHARD C.
Published: June 2006

Further evidence of chemical and mechanical mechanisms contributing to the wear process was obtained. Single‐crystal sapphire spheres were worn by a rotating steel plate, unlubricated, at sliding speeds from 1000 to 2000 fpm and loads of 2 and 4 lb. Electron microprobe analysis, Becke line analysis, and electron photomicrographs confirmed the gradual buildup of the FeO.Al2O3 spinel on the wear surface. Wear rate anisotropy as a function of sliding direction on a plane 12° to the basal plane correlated with the presence or absence of plastic flow as evidenced by slip bands. Fracture of the sapphire during wear was a function of crystal perfection and sliding direction on the basal plane.
Reactions of Glasses with Aqueous Solutions
Authors: DOUGLAS R. W. , EL‐SHAMY T. M. M.
Published: June 2006

The kinetics of the reactions of various glasses with water and aqueous solutions with pH from 1 to 13 was studied. Simple binary alkali oxide‐silica glasses were examined as well as some ternary glasses derived from the binary compositions by substituting alkaline‐earth oxides for silica. All components of the glass were determined in the extract; the glasses varied from those very easily decomposed by water to those having durability comparable to that of commercial glasses. The equilibrium conditions of the system glass‐water are distinguished from the approach to that equilibrium normally observed in such experiments. The rates of removal of various glass constituents under varied experimental conditions are reported and potential mechanisms for these reactions are discussed.
Chemical Processes During Hydrogen Reduction of Barium Titanate Crystals
Authors: AREND H. , COUFOVÁ P. , NOVÁK J.
Published: June 2006

BaTiO3 crystals prepared from fused KF contain about 0.1 wt% fluoride ions in the oxygen sites of the lattice which lead to formation of TiF4, HF, and TiF3 in addition to the formation of H2O during isothermal hydrogen reduction at high temperatures. All processes influence the number of electrons released by reduction as well as the defect structure of reduced barium titanate.