bluuebunny/crossref_metadata_2025 huggingface dataset:
Dual-color ultraviolet metal-semiconductor-metal AlGaN photodetectors
Authors: Gökkavas Mutlu , Butun Serkan , Yu HongBo , Tut Turgut , Butun Bayram , Ozbay Ekmel
Published: October 2006

Backilluminated ultraviolet metal-semiconductor-metal photodetectors with different spectral responsivity bands were demonstrated on a single AlxGa1−xN heterostructure. This was accomplished by the incorporation of an epitaxial filter layer and the recess etching of the surface. The 11nm full width at half maximum (FWHM) responsivity peak of the detector that was fabricated on the as-grown surface was 0.12A∕W at 310nm with 10V bias, whereas the 22nm FWHM responsivity peak of the detector fabricated on the recess-etched surface was 0.1A∕W at 254nm with 25V bias. Both detectors exhibited excellent dark current characteristics with less than 10fA leakage current.
Phase-matched nondegenerate four-wave mixing in one-dimensional photonic crystals
Authors: Becker C. , Wegener M. , Wong S. , von Freymann G.
Published: October 2006

The authors report on nondegenerate four-wave mixing in the near infrared using a one-dimensional chalcogenide-glass based photonic crystal. For 76 lattice constants, they find a 3.5-fold enhancement of the mixing signal with respect to the optimum-thickness bulk chalcogenide film. The key is the ability to tailor the dispersion relation of light in the photonic crystal, allowing for phase matching. Numerical calculations agree well with the experiments.
Simple and controlled single electron transistor based on doping modulation in silicon nanowires
Authors: Hofheinz M. , Jehl X. , Sanquer M. , Molas G. , Vinet M. , Deleonibus S.
Published: October 2006

A simple and highly reproducible single electron transistor (SET) has been fabricated using gated silicon nanowires. The structure is a metal-oxide-semiconductor field-effect transistor made on silicon-on-insulator thin films. The channel of the transistor is the Coulomb island at low temperature. Two silicon nitride spacers deposited on each side of the gate create a modulation of doping along the nanowire that creates tunnel barriers. Such barriers are fixed and controlled, like in metallic SETs. The period of the Coulomb oscillations is set by the gate capacitance of the transistor and therefore controlled by lithography. The source and drain capacitances have also been characterized. This design could be used to build more complex SET devices.
Optically driven micropump produced by three-dimensional two-photon microfabrication
Authors: Maruo Shoji , Inoue Hiroyuki
Published: October 2006

An optically driven lobed micropump was developed using three-dimensional two-photon microfabrication. The two built-in rotors, 9μm in diameter, are cooperatively driven by means of time-divided scanning of a single laser beam. It was demonstrated that a tracer particle was moved by simultaneously rotating the two rotors. The velocity of the tracer particle was proportional to the rotation speed of the rotors in the range of 0.2–0.7μm∕s. The flow rate was estimated to be sub-pL/min level. This ultralow flow rate will be useful for further integration and miniaturization of micro-total-analysis systems.
Disrupted motor learning and long-term synaptic plasticity in mice lacking
NMDAR1
in the striatum
Authors: Dang Mai T. , Yokoi Fumiaki , Yin Henry H. , Lovinger David M. , Wang Yanyan , Li Yuqing
Published: October 2006

Much research has implicated the striatum in motor learning, but the underlying mechanisms have not been identified. Although NMDA receptor (NMDAR)-dependent long-term potentiation has been observed in the striatum, its involvement in motor learning remains unclear. To examine the role of striatal NMDAR in motor learning, we created striatum-specific NMDAR1 subunit knockout mice, analyzed the striatal anatomy and neuronal morphology of these mice, evaluated their performance on well established motor tasks, and performed electrophysiological recordings to assay striatal NMDAR function and long-term synaptic plasticity. Our results show that deleting the NMDAR1 subunit of the NMDAR specifically in the striatum, which virtually abolished NMDAR-mediated currents, resulted in only small changes in striatal neuronal morphology but severely impaired motor learning and disrupted dorsal striatal long-term potentiation and ventral striatal long-term depression.
Androgen receptor as a licensing factor for DNA replication in androgen-sensitive prostate cancer cells
Authors: Litvinov Ivan V. , Vander Griend Donald J. , Antony Lizamma , Dalrymple Susan , De Marzo Angelo M. , Drake Charles G. , Isaacs John T.
Published: October 2006

Androgen receptor (AR) protein expression and function are critical for survival and proliferation of androgen-sensitive (AS) prostate cancer cells. Besides its ability to function as a transcription factor, experimental observations suggest that AR becomes a licensing factor for DNA replication in AS prostate cancer cells and thus must be degraded during each cell cycle in these cells to allow reinitiation of DNA replication in the next cell cycle. This possibility was tested by using the AS human prostate cancer cell lines, LNCaP, CWR22Rv1, and LAPC-4. These studies demonstrated that AR levels fluctuate both within and between various phases of the cell cycle in each of these AS lines. Consistent with its licensing ability, AR is degraded during mitosis via a proteasome-dependent pathway in these AS prostate cancer cells. In contrast, proteasome-dependent degradation of AR during mitosis is not observed in AR-expressing but androgen-insensitive human prostate stromal cells, in which AR does not function as a licensing factor for DNA replication. To evaluate mitotic degradation of AR
in vivo
, the same series of human AS prostate cancers growing as xenografts in nude mice and malignant tissues obtained directly from prostate cancer patients were evaluated by dual Ki-67 and AR immunohistochemistry for AR expression in mitosis. These results document that AR is also down-regulated during mitosis
in vivo
. Thus, AS prostate cancer cells do not express AR protein during mitosis, either
in vitro
or
in vivo
, consistent with AR functioning as a licensing factor for DNA replication in AS prostate cancer cells.
Detecting emerging strains of tuberculosis by using spoligotypes
Authors: Tanaka Mark M. , Francis Andrew R.
Published: October 2006

The W-Beijing strain of tuberculosis has been identified in many molecular epidemiological studies as being particularly prevalent. This identification has been made possible through the development of a number of genotyping technologies including spoligotyping. Highly prevalent genotypes associated with outbreaks, such as the W-Beijing strain, are implicitly regarded as fast spreading. Here we present a quantitative method to identify “emerging” strains, those that are spreading faster than the background rate inferred from spoligotype data. The approach uses information about the mutation process specific to spoligotypes, combined with a model of both transmission and mutation. The core principle is that if two comparable strains have the same number of isolates, then the strain with fewer inferred mutation events must have spread faster if the mutation process is common. Applying this method to four different data sets, we find not only the W-Beijing strain, but also a number of other strains, to be emerging in this sense. Importantly, the strains that are identified as emerging are not simply those with the largest number of cases. The use of this method should facilitate the targeting of individual genotypes in intervention programs.
TEL-AML1
transgenic zebrafish model of precursor B cell acute lymphoblastic leukemia
Authors: Sabaawy Hatem E. , Azuma Mizuki , Embree Lisa J. , Tsai Huai-Jen , Starost Matthew F. , Hickstein Dennis D.
Published: October 2006

Acute lymphoblastic leukemia (ALL) is a clonal disease that evolves through the accrual of genetic rearrangements and/or mutations within the dominant clone. The
TEL-AML1
(
ETV6-RUNX1
) fusion in precursor-B (pre-B) ALL is the most common genetic rearrangement in childhood cancer; however, the cellular origin and the molecular pathogenesis of
TEL-AML1
-induced leukemia have not been identified. To study the origin of
TEL-AML1
-induced ALL, we generated transgenic zebrafish expressing
TEL-AML1
either ubiquitously or in lymphoid progenitors.
TEL-AML1
expression in all lineages, but not lymphoid-restricted expression, led to progenitor cell expansion that evolved into oligoclonal B-lineage ALL in 3% of the transgenic zebrafish. This leukemia was transplantable to conditioned wild-type recipients. We demonstrate that
TEL-AML1
induces a B cell differentiation arrest, and that leukemia development is associated with loss of
TEL
expression and elevated
Bcl2
/
Bax
ratio. The
TEL-AML1
transgenic zebrafish models human pre-B ALL, identifies the molecular pathways associated with leukemia development, and serves as the foundation for subsequent genetic screens to identify modifiers and leukemia therapeutic targets.
A nucleobase lesion remodels the interaction of its normal neighbor in a DNA glycosylase complex
Authors: Banerjee Anirban , Verdine Gregory L.
Published: October 2006

How DNA glycosylases search through millions of base pairs and discriminate between rare sites of damage and otherwise undamaged bases is poorly understood. Even less understood are the details of the structural states arising from DNA glycosylases interacting with undamaged DNA. Recognizing the mutagenic lesion 7,8-dihydro-8-oxoguanine (8-oxoguanine, oxoG) represents an especially formidable challenge, because this oxidized nucleobase differs by only two atoms from its normal counterpart, guanine (G), and buried in the structure of naked B-form DNA, oxoG and G are practically indistinguishable from each other. We have used disulfide cross-linking technology to capture a human oxoG repair protein, 8-oxoguanine DNA glycosylase I (hOGG1) sampling an undamaged G:C base pair located adjacent to an oxoG:C base pair in DNA. The x-ray structure of the trapped complex reveals that the presence of the 8-oxoG drastically changes the local conformation of the extruded G. The extruded but intrahelical state of the G in this structure offers a view of an early intermediate in the base-extrusion pathway.
Variation at the ratCrhr1locus and sensitivity to relapse into alcohol seeking induced by environmental stress
Authors: Hansson A. C. , Cippitelli A. , Sommer W. H. , Fedeli A. , Björk K. , Soverchia L. , Terasmaa A. , Massi M. , Heilig M. , Ciccocioppo R.
Published: October 2006

Alcoholism is a chronic relapsing disorder with substantial heritability. Uncovering gene–environment interactions underlying this disease process can aid identification of novel treatment targets. Here, we found a lowered threshold for stress-induced reinstatement of alcohol seeking in Marchigian–Sardinian Preferring (msP) rats genetically selected for high alcohol preference.In situhybridization for a panel of 20 stress-related genes in 16 brain regions was used to screen for differential gene expression that may underlie this behavioral phenotype. An innate up-regulation of theCrhr1transcript, encoding the corticotropin-releasing hormone receptor 1 (CRH-R1), was found in several limbic brain areas of msP rats genetically selected for high alcohol preference, was associated with genetic polymorphism of theCrhr1promoter, and was accompanied by increased CRH-R1 density. A selective CRH-R1 antagonist (antalarmin, 10–20 mg/kg) was devoid of effects on operant alcohol self-administration in unselected Wistar rats but significantly suppressed this behavior in the msP line. Stress-induced reinstatement of alcohol seeking was not significantly affected by antalarmin in Wistar rats but was fully blocked in msP animals. These data demonstrate thatCrhr1genotype and expression interact with environmental stress to reinstate alcohol-seeking behavior.
A role for WRN in telomere-based DNA damage responses
Authors: Eller Mark S. , Liao Xiaodong , Liu SuiYang , Hanna Kendra , Bäckvall Helena , Opresko Patricia L. , Bohr Vilhelm A. , Gilchrest Barbara A.
Published: October 2006

Telomeres cap the ends of eukaryotic chromosomes and prevent them from being recognized as DNA breaks. We have shown that certain DNA damage responses induced during senescence and, at times of telomere uncapping, also can be induced by treatment of cells with small DNA oligonucleotides homologous to the telomere 3′ single-strand overhang (T-oligos), implicating this overhang in generation of these telomere-based damage responses. Here, we show that T-oligo-treated fibroblasts contain γH2AX foci and that these foci colocalize with telomeres. T-oligos with nuclease-resistant 3′ ends are inactive, suggesting that a nuclease initiates T-oligo responses. We therefore examined WRN, a 3′ → 5′ exonuclease and helicase mutated in Werner syndrome, a disorder characterized by aberrant telomere maintenance, premature aging, chromosomal rearrangements, and predisposition to malignancy. Normal fibroblasts and U20S osteosarcoma cells rendered deficient in WRN showed reduced phosphorylation of p53 and histone H2AX in response to T-oligo treatment. Together, these data demonstrate a role for WRN in processing of telomeric DNA and subsequent activation of DNA damage responses. The T-oligo model helps define the role of WRN in telomere maintenance and initiation of DNA damage responses after telomere disruption.
Regulation of myogenic progenitor proliferation in human fetal skeletal muscle by BMP4 and its antagonist Gremlin
Authors: Frank Natasha Y. , Kho Alvin T. , Schatton Tobias , Murphy George F. , Molloy Michael J. , Zhan Qian , Ramoni Marco F. , Frank Markus H. , Kohane Isaac S. , Gussoni Emanuela
Published: October 2006

Skeletal muscle side population (SP) cells are thought to be “stem”-like cells. Despite reports confirming the ability of muscle SP cells to give rise to differentiated progeny in vitro and in vivo, the molecular mechanisms defining their phenotype remain unclear. In this study, gene expression analyses of human fetal skeletal muscle demonstrate that bone morphogenetic protein 4 (BMP4) is highly expressed in SP cells but not in main population (MP) mononuclear muscle-derived cells. Functional studies revealed that BMP4 specifically induces proliferation of BMP receptor 1a–positive MP cells but has no effect on SP cells, which are BMPR1a-negative. In contrast, the BMP4 antagonist Gremlin, specifically up-regulated in MP cells, counteracts the stimulatory effects of BMP4 and inhibits proliferation of BMPR1a-positive muscle cells. In vivo, BMP4-positive cells can be found in the proximity of BMPR1a-positive cells in the interstitial spaces between myofibers. Gremlin is expressed by mature myofibers and interstitial cells, which are separate from BMP4-expressing cells. Together, these studies propose that BMP4 and Gremlin, which are highly expressed by human fetal skeletal muscle SP and MP cells, respectively, are regulators of myogenic progenitor proliferation.
Role of FIP200 in cardiac and liver development and its regulation of TNFα and TSC–mTOR signaling pathways
Authors: Gan Boyi , Peng Xu , Nagy Tamas , Alcaraz Ana , Gu Hua , Guan Jun-Lin
Published: October 2006

Focal adhesion kinase family interacting protein of 200 kD (FIP200) has been shown to regulate diverse cellular functions such as cell size, proliferation, and migration in vitro. However, the function of FIP200 in vivo has not been investigated. We show that targeted deletion of FIP200 in the mouse led to embryonic death at mid/late gestation associated with heart failure and liver degeneration. We found that FIP200 knockout (KO) embryos show reduced S6 kinase activation and cell size as a result of increased tuberous sclerosis complex function. Furthermore, FIP200 KO embryos exhibited significant apoptosis in heart and liver. Consistent with this, FIP200 KO mouse embryo fibroblasts and liver cells showed increased apoptosis and reduced c-Jun N-terminal kinase phosphorylation in response to tumor necrosis factor (TNF) α stimulation, which might be mediated by FIP200 interaction with apoptosis signal–regulating kinase 1 (ASK1) and TNF receptor–associated factor 2 (TRAF2), regulation of TRAF2–ASK1 interaction, and ASK1 phosphorylation. Together, our results reveal that FIP200 functions as a regulatory node to couple two important signaling pathways to regulate cell growth and survival during mouse embryogenesis.
Cdc42 GEF Tuba regulates the junctional configuration of simple epithelial cells
Authors: Otani Tetsuhisa , Ichii Tetsuo , Aono Shinya , Takeichi Masatoshi
Published: October 2006

Epithelial cells are typically arranged in a honeycomb-like pattern, minimizing their cell–cell contact areas, which suggests that some tension operates for shaping of the cell boundaries. However, the molecular mechanisms that generate such tension remain unknown. We found that Tuba, which is a Cdc42-specific GEF, was concentrated at the apical-most region of cell junctions in simple epithelia via its interaction with ZO-1. RNAi–mediated depletion of Tuba altered the geometrical configuration of cell junctions, resulting in a curved and slack appearance. At the subcellular level, Tuba inactivation modified the assembly pattern of junctional F-actin and E-cadherin. Tuba RNAi also retarded cell junction formation in calcium-switch experiments. Suppression of Cdc42 activity or depletion of N-WASP, which is an effector of Cdc42, mimicked the effects of Tuba depletion. Conversely, overexpression of dominant-active Cdc42 or N-WASP enhanced the junction formation of Tuba-depleted cells. These results suggest that Tuba controls the shaping of cell junctions through the local activation of Cdc42 and its effectors.
BMP1 controls TGFβ1 activation via cleavage of latent TGFβ-binding protein
Authors: Ge Gaoxiang , Greenspan Daniel S.
Published: October 2006

Transforming growth factor β1 (TGFβ1), an important regulator of cell behavior, is secreted as a large latent complex (LLC) in which it is bound to its cleaved prodomain (latency-associated peptide [LAP]) and, via LAP, to latent TGFβ-binding proteins (LTBPs). The latter target LLCs to the extracellular matrix (ECM). Bone morphogenetic protein 1 (BMP1)–like metalloproteinases play key roles in ECM formation, by converting precursors into mature functional proteins, and in morphogenetic patterning, by cleaving the antagonist Chordin to activate BMP2/4. We provide in vitro and in vivo evidence that BMP1 cleaves LTBP1 at two specific sites, thus liberating LLC from ECM and resulting in consequent activation of TGFβ1 via cleavage of LAP by non–BMP1-like proteinases. In mouse embryo fibroblasts, LAP cleavage is shown to be predominantly matrix metalloproteinase 2 dependent. TGFβ1 is a potent inducer of ECM formation and of BMP1 expression. Thus, a role for BMP1-like proteinases in TGFβ1 activation completes a novel fast-forward loop in vertebrate tissue remodeling.
The bHLH-PAS protein Spineless is necessary for the diversification of dendrite morphology of Drosophila dendritic arborization neurons
Authors: Kim Michael D. , Jan Lily Yeh , Jan Yuh Nung
Published: October 2006

Dendrites exhibit a wide range of morphological diversity, and their arborization patterns are critical determinants of proper neural connectivity. How different neurons acquire their distinct dendritic branching patterns during development is not well understood. Here we report that Spineless (Ss), the Drosophila homolog of the mammalian aryl hydrocarbon (dioxin) receptor (Ahr), regulates dendrite diversity in the dendritic arborization (da) sensory neurons. In loss-of-function ss mutants, class I and II da neurons, which are normally characterized by their simple dendrite morphologies, elaborate more complex arbors, whereas the normally complex class III and IV da neurons develop simpler dendritic arbors. Consequently, different classes of da neurons elaborate dendrites with similar morphologies. In its control of dendritic diversity among da neurons, ss likely acts independently of its known cofactor tango and through a regulatory program distinct from those involving cut and abrupt. These findings suggest that one evolutionarily conserved role for Ahr in neuronal development concerns the diversification of dendrite morphology.
Telomerase RNA level limits telomere maintenance in X-linked dyskeratosis congenita
Authors: Wong Judy M.Y. , Collins Kathleen
Published: October 2006

Dyskeratosis congenita (DC) patients suffer a progressive and ultimately fatal loss of hematopoietic renewal correlating with critically short telomeres. The predominant X-linked form of DC results from substitutions in dyskerin, a protein required both for ribosomal RNA (rRNA) pseudouridine modification and for cellular accumulation of telomerase RNA (TER). Accordingly, alternative models have posited that the exhaustion of cellular renewal in X-linked DC arises as a primary consequence of ribosome deficiency or telomerase deficiency. Here we test, for the first time, whether X-linked DC patient cells are compromised for telomerase function at telomeres. We show that telomerase activation in family-matched control cells allows telomere elongation and telomere length maintenance, while telomerase activation in X-linked DC patient cells fails to prevent telomere erosion with proliferation. Furthermore, we demonstrate by phenotypic rescue that telomere defects in X-linked DC patient cells arise solely from reduced accumulation of TER. We also show that X-linked DC patient cells averted from premature senescence support normal levels of rRNA pseudouridine modification and normal kinetics of rRNA precursor processing, in contrast with phenotypes reported for a proposed mouse model of the human disease. These findings support the significance of telomerase deficiency in the pathology of X-linked DC.
NOTES ON CONE 10 SAGGER BODIES WITH TALC AS A COMPONENT*
Authors: THIEMECKE H.
Published: October 2006

The effect of introducing talc in amounts not exceeding 25% on some of the properties of a sagger body was investigated. The results obtained show improved working properties of the body in the plastic state, increased dry and fired mechanical strength, decreased absorption, lower thermal expansion, increased heat‐shock resistance, decreased total shrinkage, decreased sag tendency, smoother fired surface, and darkening of fired color. Talc in amounts greater than 15% shows no appreciable increased benefits, indicating this content to be the practical limit for a commercial cone 10 sagger composition.
THE EFFECT OF GLAZE COMPOSITION UPON THE COLORS PRODUCED BY SODIUM URANATE*
Authors: KAUTZ KARL
Published: October 2006

A study was made of the effect of glaze composition upon the colors produced by sodium uranate at cones 6 to 7 in which hundreds of trials were made. Typical compositions of glazes are given which react with sodium uranate to produce green, yellow, ivory, orange, and red colors. Notes on the effect the different glaze constituents have upon the color are also given.
FACTORS INVOLVED IN THE PRODUCTION OF GLAZED BRICK BY THE DRY‐PRESS PROCESS*
Authors: RUECKEL W. C.
Published: October 2006

Brick were made by the dry‐press process from two fire clays with varying grain size, moisture content, and forming pressure. The effect of de‐airing the mold box prior to compression was also studied. Glazed brick made in this investigation were compared with stiff‐mud glazed brick and the properties of the former were found to equal those of the stiff‐mud glazed brick when the forming variables were closely controlled.
APPROXIMATE COMPOSITION OF THE LOWEST FUSING MIXTURE OF BARIUM OXIDE, MAGNESIUM OXIDE, AND SILICA*
Authors: TURNER CECIL H.
Published: October 2006

Varying mixtures of BaO, MgO, and SiO2 were made into cones and fired to determine the temperature at which they would fuse. The direction of falling temperature as determined by their relative fusion temperatures converged to an area whose center represented a mixture, the composition of which was approximately 46.0% by weight of BaO, 8.0% by weight of MgO, and 46.0% by weight of SiO2. The first signs of fusion occurred in this mixture at standard pyrometric cone 1 (3 o'clock).
A STUDY OF THE MINERALOGICAL AND PHYSICAL CHARACTERISTICS OF TWO LITHIA‐ZIRCONIA BODIES*
Authors: BARLETT HELEN BLAIR , THOMAS R. R.
Published: October 2006

Two bodies differing in composition by a small percentage only of Li2O were found to show marked differences in physical properties, particularly in thermal expansion Petrographic examinations were made of the electric‐furnace products used as the nonplastics and of the fired porcelain to determine what structural or mineralogical differences might be responsible for these variations. The properties of a feldspar body, tested under similar conditions, are given for comparative purposes.
METHODS OF DETERMINING THE CONSTITUTION OF GLASSES*
Authors: PRESTON ERIC , TURNER W. E. S.
Published: October 2006

Methods of determining the constitution of glasses are discussed rather than the presentation of data on glass constitution. The equilibrium diagram method involves the destruction of the glassy condition but indicates the compounds which may be formed. The meaning of the change in state at a temperature some 40° below its softening point is still obscure. Light‐absorption studies indicate solvation. Data on five different physical properties are interpreted in the light of equilibrium diagram data as follows: (1) specific volume, (2) thermal expansion, (3) refractive index, (4) electrical resistance, and (5) vapor tension and volatilization, the first three of which are not decisive. Electrical resistance data indicate presence of Na2O.2SiO2. Volatilization data indicate presence of Na2O.2SiO2 and K2O.4SiO2.
EFFECT OF TEMPERATURE TREATMENT ON ABRASIVES AND ABRASIVE PRODUCTS*
Authors: PURDY ROSS C.
Published: October 2006

The thermal effect on properties of the abrasive grains and on the combination of grains with bonds is discussed and its importance on the properties of the completed product are set forth.
THE PHYSICAL PROCESSES OCCURRING IN THE MELTING AND COOLING OF GLASS
Authors: LITTLETON J. T.
Published: October 2006

The thermal treatment of glass is followed from the melting and refining stage downward through the annealing zone. The fusion of the batch constituents is shown to be completed in a short time and the greater portion of the time required to obtain glass of good quality is used in freeing the glass from gas bubbles and in improving the homogeneity. It is postulated that melting is similar to a diffusion process, the constituents being mixed by diffusion aided by convection currents. A review of the evidence for silicate compounds in glasses shows that only electrical conductivity data indicate the existence of such compounds. Dissolved gases probably assist fining by diffusing into the bubbles and increasing their size. This offers one explanation of the action of fining agents. Devitrification is shown to be avoidable by a knowledge of the devitrification emperature and staying above this temperature during melting and fining. Any subsequent cooling through the devitrification zone should be rapid. The earlier annealing equations are based on the experimental observation that rate of release of stress in glass is proportional to the square of the stress. This fact is difficult to explain on a physical basis when it is assumed that viscosity is constant with temperature. However, data are cited which show that viscosity changes with time and when the instantaneous values of viscosity are used it is shown that the rate of release of stress is proportional to the stress divided by the viscosity. The constant of proportionality has the dimensions of the shear modulus of glass and is equal to one‐fourth the value of the shear modulus in glass at room temperature.
THE MEASUREMENT OF REACTION RATES AT HIGH TEMPERATURES*
Authors: CEESTERS J. H. , PARMELEE C. W.
Published: October 2006

Cylindrical test pieces, rammed under a pressure of 10,000 pounds per square inch, were heated to temperatures varying between 1300°C and 1500°C. The rate of inversion of quartz to cristobalite and the rate of spinel formation in mixtures of electrically fused magnesia and alumina were determined from the slope of the expansion curve at constant temperature. The amount of cristobalite or spinel formed was calculated from the density determinations before and after firing. The products were identified by X‐ray and microscopic investigation.

Unfired silica brick showed almost complete inversion to cristobalite after two hours at 15OO°C, the corresponding vertical expansion being about 6%. The addition of 2% CaO to unfired quartzite was found to increase the rate of inversion to cristobalite quite appreciably. A further addition of 1.5% Na2O + 1.5% Fe2O8 so increased the rate of inversion at 1400° that after two hours only cristobalite appeared to be present.

A mixture of electrically fused magnesia (0.15 to 0.06 millimeter grain size) and alumina (3.59 to 0.15 millimeter grain size) was found to contain about 25% spinel after two hours at 1500°C. The addition of 2% B2O3 increased the amount of spinel formed under similar conditions to 75%. Test pieces made solely from magnesia and alumina of one grain size (0.06 millimeter) showed complete conversion to spinel after only ten minutes at 1450° C. The sensitivity of this method of studying reaction rates is such that an expansion of one scale division is equivalent to the formation of 0.1% of spinel.
A SIMPLE METHOD FOR OBTAINING PHOTOGRAPHIC RECORDS OF TIME‐SETTLE CURVES WITH ELUTRIATION*
Authors: GOLLNOW G.
Published: October 2006

An “elutriator” is described which does not elutriate but gives the opportunity to obtain a photographic record of the rate of settle of different sized particles. The apparatus and its operation are briefly given.
APPLICATION OF STOKES' LAW IN THE DETERMINATION OF THE ABSOLUTE VISCOSITY OF GLASS*
Authors: HUNTER R. G.
Published: October 2006

Stokes' law, with a modified form of Ladenburg's wall‐correction factor, has been applied to determine the viscosity of glass from the velocity of a freely falling platinum sphere. The apparatus is described in full, a special feature being the radio equipment used to measure the velocity of the falling sphere.

Reproducibility of results is excellent and good agreement has been obtained using spheres of different diameters, vindicating the use of the revised wall‐correction factor. Results on a few typical glasses are discussed.
THE EFFECT OF MECHANICAL PRESSURE ON THE DRYING AND FIRING PROPERTIES OF TYPICAL CERAMIC BODIES*
Authors: WESTMAN A. E. R.
Published: October 2006

The drying and firing properties of hand‐molded and permeable‐pressed disks, 2 3/4 inches in diameter and 11/2 inches thick, were determined for sanitary ware, semivitreous ware, electrical porcelain, glass pot, sewer pipe, and chemical stoneware. Permeable pressing at 8280 lb./sq. in. eliminated drying shrinkage, reduced firing shrinkage by nearly one‐half, and the combined shrinkage by from one‐half to two‐thirds. The majority of the disks were dried and fired successfully, but some cracked on drying, probably from thermal shock, and some pressed disks were insufficiently oxidized or reduced due to their dense structure. Studies of pressing times showed great differences between bodies and, for any one body, that the pressing time depended roughly on the square of the initial thickness of the disk.
A RAPID METHOD FOR THE ANALYSIS OF SILICEOUS REFRACTORIES*
Authors: COLE SANDFORD S. , SCHOLES S. R.
Published: October 2006

Evaporation with HF and H2SO4 removes silica. Ignition of residue at 800 to 900 °C yields a mixture of R2O3 and sulfates, which is weighed. The residue is brought into solution and R2O3O, CaO3 and MgO are determined by standard methods. CaO and MgO are calculated back to sulfates and alkali is calculated from weight of ignited residue. Silica is found by difference. A summary of previous investigations of the behavior of sulfates at elevated temperatures is presented, as well as the results of similar experiments by the authors.
OBSERVATIONS ON SPALLING*
Authors: PRESTON F. W. , WHITE H. E.
Published: October 2006

If a sphere of clay at room temperature be immersed suddenly in a red hot furnace, spalls fly off its surface. These spalls are more or less circular disks, of somewhat definite thickness. They do not form instantly, but a finite time elapses between immersion and spalling. This time interval also is consistent and definite.

The hotter the furnace, the shorter the time interval and the thinner the spall.

According to the experiments, the thickness of the spall is proportional to the square root of the time interval; it is also inversely proportional to the fourth power of the absolute temperature. The first relation implies, apparently, that the controlling factor in the clay is the thermal diffusivity; the second relation implies that the connection between the clay and the furnace is radiant heat. Both implications seem entirely sensible.

The addition of an inert material of relatively high diffusivity accentuates the rôle that this factor plays in the resistance to spalling of clayware. These experiments were carried out by adding Sic flour in increasing amounts to the clay batch.

The views of the Refractories Division are sought before extending the work to geological problems.
A FURTHER PROGRESS REPORT ON THE STUDY OF GASES IN ENAMELING IRON*
Authors: LUCIAN A. N. , KAUT KARL
Published: October 2006

Spectrographic analyses were made of the gases evolved when enameling iron, ground‐coat enamel, and iron enameled in ground coat were heated in vacuo at various temperatures. Below 1200°F the gases from enameling iron contained hydrogen, water vapor, carbon monoxide, carbon dioxide, and nitrogen. Between 1200°F and 1600°F. the gases from enameling iron contained carbon monoxide, carbon dioxide, and nitrogen. The gases from dried ground‐coat enamel slip at temperatures not exceeding 1600 F consisted principally of water vapor. The gases from ground‐coat enameled iron (reboiling gases) contained hydrogen, water vapor, carbon monoxide, carbon dioxide, and nitrogen.
VITRIFIABLE COLORS FOR DECORATING GLASSWARE*
Authors: DOUGHERTY W. E.
Published: October 2006

The use of vitrifiable colors to be applied and fused on glassware is discussed. A brief history of the art is given, together with a discussion of the chemical composition and manufacture of the various types of colors.
BLISTERING AND CRAWLING OF GLAZES CAUSED BY UNDERSLIPS*
Authors: SCHURECHT H. G.
Published: October 2006

Blistering of glazes during spraying and crawling during firing may be caused by the use of improper underslips. Blistering may be reduced by increasing the amount of clay in the underslip and reducing the more nonplastic ingredients. Crawling may be prevented by reducing the shrinkage and increasing the dry strength of the underslips.
THE INFLUENCE OF COMPOSITION OF THE FELDSPAR CONSTITUENT ON THE PROPERTIES OF A PORCELAIN BODY*
Authors: CHILCOTE JOSEPH H.
Published: October 2006

An investigation is presented covering industrial application of potash soda, lime‐soda feldspars as represented by commercial microcline, albite, and andesine, respectively, and various mixtures of these feldspars were chosen on the basis of a study of the potash, soda, lime‐soda feldspar system. These feldspars and mixtures were incorporated in a typical porcelain body and were prepared and formed according to normal practice for a plastic body.
QUANTITATIVE DETERMINATION OF AIR CONTENT IN PLASTIC CLAY OR POROUS BODIES*
Authors: LAPP G. W.
Published: October 2006

An instrument mentioned in a previous paper1 is more fully described with operating notes on it use. The voids in clay or porous material are eliminated by compression in a bomb having an operating piston with leak‐proof packing. Air content is compressed into solution in the liquid present. By this means minute quantities of air or other data can be determined in a few minutes by direct reading. The test is made without change in state and is free from the errors of disintegration‐by‐heating methods.
MECHANICS OF ENAMEL ADHERENCE. IX*
Authors: SPENCER‐STRONG G. H. , KING R. M.
Published: October 2006

The crystal phases separating at the enamel‐iron interface under conditions approaching equilibrium between the various components of the system have been determined and are discussed.
CORRELATION OF VISCOSITY MEASUREMENTS WITH FLOW OF GLASS*
Authors: RICHARDSON H. K.
Published: October 2006

The following paper describes the transformation from the rule‐of‐thumb state to a scientifically controlled process of the filling of the glass insulation into the brass shells for incandescent lamp bases. It is divided into three parts: (a) the development of the platinum alloy dies or orifices, (b) determination of the flow of glass through the platinum dies or orifices, and (c) automatic control of glass‐stream temperature by means of radiation pyrometers.

For three decades or more this process has been in operation. Wonderful strides have taken place in the development of the machinery needed until at present the medium screw base (No. 102) for general home lighting is filled with glass and the glass is shaped at the rate of 220 per minute. Actually 12,000 bases are processed per hour by this machine, which is known as a glass base machine.

In brief, the process consists of indexing a brass shell and eyelet held in a proper holder under a flowing stream of glass, cutting the stream, pressing the glass into shape, cleaning the glass from the eyelet holes, and blowing the hot base off into an annealer for cooling.

Control of the glass stream lagged woefully behind the development of the machines and represented a strictly rule‐of‐thumb handling. The crux of the difficulty was the constantly varying size of the orifice through which the glass is delivered to the glass base machine. A porcelain die was used for this purpose and quickly enlarged due to erosion.

The development of a platinum alloy‐lined refractory die solved the problem of the varying size of the orifice. While this development was being carried on, the field of automatic control for the oil‐fired tank was kept continually in mind and various promising installations were experimented with. Thus when the unvarying orifice was developed, the whole process of control was immediately available.

The present status of this work as here described does not represent a perfect solution but only the present situation which is subject to further improvement.
PYROMETRIC CONE‐EQUIVALENT VALUES FOR THE CaO‐Al2OrSiO2 SYSTEM*
Authors: ZVANUT FRANK , WILSON HEWITT
Published: October 2006

A diagram and table were prepared showing the cone‐equivalent values of the principal compositions in the lime‐alumina—silica system for use in refractories, Portland cement, and metallurgical operations.
QUANTITATIVE MICROSCOPIC DETERMINATION OF THE QUARTZ CONTENT OF COMMERCIAL GROUND FELDSPARS*
Authors: THOMPSON C. L.
Published: October 2006

The literature on quantitative microscopic analyses is briefly reviewed. A variation in technique applied to fused feldspar samples is described. The results are compared with values obtained by calculation from the chemical compositions of the samples. The reproducibility of the results is demonstrated.
THE DURABILITY OF TABLEWARE DECORATIONS*
Authors: KOENIG C. J. , WATTS A. S.
Published: October 2006

(1) A survey is given of European research on over‐glaze decorated tableware tested with various solutions, which are indicated as simulating practical service. (2) A study has been made of some typical European and American tableware with overglaze decorations tested in commercial dishwashing solutions and also in various other solutions which may be encountered in service. Results indicate that acids are harmful on cobalt blues in practically all cases. Alkalis are harmful to practically all decorations, apparently through the destruction of the flux used in preparing the colors. Some commercial cleaning solutions are much more destructive than others.
NOTES ON CASTING SLIP*
Authors: SCHRAMM EDWARD , HALL F. P.
Published: October 2006

Casting behavior depends on the properties of the mold, the slip, and the casting formed. The water retention of the casting is of especial significance, and experiments reveal how this depends on the nature and condition of the slip. Tannic and gallic acids as deflocculents are more effective when used in the form of sodium salts. These organic agents serve as protective colloids to reduce attack on molds.
NOTES ON SOME EFFECTS OF THE VARIETY OF FLINT USED ON THE PROPERTIES OF A HOTEL CHINA BODY*
Authors: THOMPSON C. L.
Published: October 2006

Pebble, sand, rock, and tripoli flint were used in a hotel china composition. The variety of flint was found to have little effect on the water absorption of the body fired to cone 10, on its linear thermal expansion to 300°C, or on its impact strength. The pebble‐flint body crazed most easily in a water‐dip test, while the sand‐flint body was most resistant to crazing. The body containing rock flint was superior in translucency, the sand flint next, the tripoli flint third, while the pebble‐flint body was practically opaque.
ELECTRICAL LUBRICATION OF STIFF‐MUD DIES*
Authors: EVERHART J. O.
Published: October 2006

The history of the lubrication of dies and of electro‐lubrication is presented, and plant and laboratory tests are given in detail. The electrolytes used, potassium hydroxide, hydrochloric acid, and ferric sulfate, are discussed. Electrical lubrication of dies is recommended with certain precautions cited in its adaptation.
FURTHER STUDIES OF THE TUNNEL KILN*
Authors: RICHARDSON W. D.
Published: October 2006

Reasons are given as to why the tunnel kiln seems to be the best type of kiln for structural clay products. The downdraft tunnel kiln is the most efficient and most practical form of kiln for most clay products.

The improvements made in the Richardson downdraft tunnel kiln are described. Recent improvements in the flat suspened arch are described and illustrated and improvements in car frame, car platform, and baffle are given.

A new tunnel kiln, the Richardson muffle‐car, double‐track tunnel kiln, is also described and illustrated. This kiln is thought to be well adapted for floor and wall tile and some pottery, saving in handling and breakage of saggers.
EFFECT OF DELAY IN ENAMELING PICKLED SHEET IRON*
Authors: PORST E. G. , WOLFRAM H. G.
Published: October 2006

The effect of delay in enameling pickled sheet iron is shown as promoting copperheads in the ground coat. This is especially true of the old type of viscous single‐glass ground coat. The modern two‐glass ground coat was not affected by the pickling procedure.
THE GRAPHICAL COMPUTATION OF OPACITY OF PORCELAIN ENAMELS*
Authors: MCINTYRE G. H.
Published: October 2006

The use and calculation of reflectivity data in connection with opacity is discussed.
STRESSES IN WIRE GLASS ARISING FROM THE WIRE*
Authors: PRESTON FRANK W.
Published: October 2006

This paper deals with the polariscopic appearance of certain types of wire glass having the wire set eccentrically in the thickness. The glass, being wholly in compression, appears at first sight to be out of equilibrium, but when the stress in the wire is taken account of, the distribution is seen to be normal.
ELECTRICAL LUBRICATION OF HAND‐MOLDED REFRACTORY SHAPES*
Authors: EVERHART J. OTIS
Published: October 2006

It is possible to release hand‐molded shapes from metal molds by use of direct current without the use of oil, sand, or grog on the interior of the mold. A discussion of the principles involved is presented with observations made while conducting practical tests in an Ohio refractories plant.
FURTHER DATA ON REBOILING OF SHEET‐IRON GROUND‐COAT ENAMELS*
Authors: ANDREWS A. I. , MULLADY R. E.
Published: October 2006

The reported characteristics of the reboiling phenomenon have been checked and additional data which influence reboiling have been obtained.
A STUDY OF WHITE GROUND COATS*
Authors: TETRICK JAMES D.
Published: October 2006

Strong and uniform adherence in white ground‐coat enamels can be promoted through special preparation of the enameling stock either through a plating operation or by deep etching the surface. The results obtained depend upon uniformity of the preparation of the base metal and the composition of the ground‐coat enamels used.

It is necessary to compound the white ground‐coat enamel with considerable amounts of the accessory opacifiers in order to build up satisfactory opacity. Additions of opacifiers to the mill are also necessary. Fluidity of the enamel is important and should be high to decrease reboiling and to produce a smooth finish coat on etched stock. Addition of antimony trioxide to the raw batch of the enamel promotes adherence but develops reboiling.
AN UNDESCRIBED VARIETY OF FLINT CLAY*
Authors: GALPIN S. L. , NOLTING J. P.
Published: October 2006

The location, physical and working properties, chemical composition, and microscopic character of this flint, which has not hitherto been described, are presented.
NOTES ON CONE 10 RAW CRYSTAL GLAZE*
Authors: THIEMECKE H.
Published: October 2006

A typical composition of a cone 10 raw glaze that possesses pronounced devitrification characteristics of commercial possibilities is given. The percentage limits of the components of the glaze, the rates of cooling and heating up, as well as the temperature range in which crystals are producible were determined. The effects of adding various types and amounts of colorants on the color and the color intensities of the crystals and the glass matrix are discussed. Optical data indicate the crystals to be members of the pyroxene group.
AN APPARATUS FOR MEASURING THE THERMAL CONDUCTIVITY OF REFRACTORIES AT HIGH TEMPERATURES*
Authors: Finck J. L.
Published: October 2006

An‘apparatus is described for measuring the thermal conductivity of refractories at temperatures up to about 2000°F. The theory and method of test are discussed in detail and results are given on a light refractory insulating brick and also on a silica fire brick and dense clay fire brick.
INSULATING REFRACTORIES*
Authors: Hepburn W. M.
Published: October 2006

Insulating materials of various types are discussed and their installation in air heaters, carbottom, walking‐beam bright annealing, standard, bell‐type, and wire patenting furnaces, and glass leers is described. Data on the savings involved in the use of insulating refractories are given. The characteristics of the materials are uniformity of product, shrinkage and spalling properties, physical strength, insulating value, and thermal capacity.
PHYSICAL PROPERTIES OF SOME INSULATING BRICK*
Authors: Rueckel Walter C.
Published: October 2006

An investigation of eleven types of insulating brick was made. Physical properties determined included bulk density, porosity, transverse and crushing strength, pyrometric cone equivalent, volume shrinkage at 2300°F, 2500°F, and 2700°F, load deformation at elevated temperatures, and resistance to spalling. A study of the relation between permeability and pressure differential through the various insulating brick is included in the report.

Suggestions for classifying the various types of insulating brick into groups and a critical discussion of formulas for permeability are also given.
EFFECT OF VARIATIONS IN THE ALUMINA‐SILICA RATIO IN FUSED REFRACTORY MATERIALS UPON RESISTANCE TO METAL OXIDES*
Authors: Mcmullen Charles , Turner A. A. , Easter G. J.
Published: October 2006

Solid pieces of electrically fused material, varying in composition from 630%, alumina 37%, silica to 100% alumina, of the ordinary abrasive grade were heated in contact with cast iron and brass which were allowed to oxidize and attack the refractory. The least attack was found in the case of the iron with 80% alumina 20% silica, and in the case of the brass with straight alumina, although the 80% alumina 20% silica was not greatly inferior.

Bonds were developed for the materials thus selected and confirmatory tests were made on crucible fusions. Arc and powdered‐coal furnaces lined with the bonded materials have proved successful.