bluuebunny/crossref_metadata_2025 huggingface dataset:
Cloning and sequencing of the cDNA encoding the pituitary gonadotropin II β‐subunit of yellowfin porgy (Acanthopagrus latus)
Authors: Tsai Huai‐Jen , Yang Liang‐Tung
Published: June 2006

The complementary DNA (cDNA) encoding the gonadotropic hormone (GTH) II pre‐β‐subunit of yellowfin porgy (Acanthopagrus latus) was isolated from a pituitary gland cDNA phage library. The cDNA insert, 598 base pairs (bp), contained a 411 bp open reading frame with 35 bp and 152 bp flanking regions at the 5′‐ and 3′‐ends, respectively. The deduced amino acid sequence revealed a putative signal peptide of 24 amino acid residues and a 113 amino acid mature β‐subunit of GTH polypeptide. This pre‐β‐subunit polypeptide of the yellowfin porgy GTH II showed 86% sequence identity with that of bonito GTH II‐β 73% with killifish GTH II‐β, 63% with African catfish GTH II‐β 61% with pike eel GTH‐β, 60% with silver carp GTH‐β, 59% with chum salmon GTH 11‐β, 58% with common carp GTH‐β 57% with chinook Pacific salmon GTH‐β, and 53% with European eel GTH II‐β.
The effect of gradual transfer to sea water on muscle carbohydrate metabolism of rainbow trout
Authors: Soengas J. L. , Fuentes J. , Andrés M. D. , Aldegunde M.
Published: June 2006

An assessment of the levels of glycogen and glucose, as well as of the activity of several key enzymes of glycogenolysis, glycolysis, gluconeogenesis and the pentose phosphate shunt were performed in white and red muscle of rainbow trout (Oncorhynchus mykiss) of two different sizes, 97.03 ± 3.03 g (small, n=67) and 165.69 ± 5.01 g (large, n= 68) during gradual transfer to sea water using salinities of 0, 9, 18 and 28 ppt. The results indicate the existence of changes in carbohydrate metabolism in both white and red muscle. Glycogenolysis was observed for both types of muscle associated with increased salinity. The glucose obtained from glycogen breakdown appears to be used in situ in the white muscle of both sizes of animal through increased glycolysis, this is also the case for the red muscle but only for small animals. In neither white or red muscle, were major changes detected in gluconeogenesis, the pentose phosphate shunt or in the use of exogenous glucose. The metabolic changes described are indirectly related to the increased energetic demand occurring during adaptation of rainbow trout to sea water. No main differences were observed between size for the parameters studied except in red muscle probably reflecting a better adaptation of large animals to sea water.
Electron microscopic studies on the retinal photoreceptors of the spotted snakehead, Channa punctatus
Authors: Narayanan K. , Khan A. A.
Published: June 2006

The retinal photoreceptors of Channa punctatus include rods, single cones and the double cones. The double cones have the outer segments having lamellae which are distorted into tubules and vesicles, and the inner segments with hypertrophied mitochondria.
Exploratory deep‐sea fishing in the Falkland Islands, south‐western Atlantic
Authors: Coggan R. A. , Nolan C. P. , George M. J. A.
Published: June 2006

Records of demersal deep‐sea fish assemblages in waters around the Falkland Islands (Patagonian shelf area) are rare. Twenty deep‐water stations to the east and south of the Falkland Islands were sampled by commercial bottom trawl deployed in upper, middle and lower benthopelagic zones (depth range of approximately 500‐1000 m). Forty‐one species (22 families) of teleost fish were recorded, 10 species (two families) of elasmobranch and one species of agnathan. Different assemblages of fish were found to characterize each depth zone (e.g. Moridae in deeper waters, Bothidae and Rajidae in shallower waters), with diversity being greatest in the mid‐zone and biomass greatest in the upper and lower zones. Some species occurred in all zones but showed depth‐related abundance. Four species, namely the grenadiers Macrourus carinutus and Coelorhynchus fasciatus, the southern blue whiting Micromesistius australis, and the Patagonian toothfish Dissostichus eleginoides, accounted for 85% by weight of all fish caught. Quantitative sampling of selected species revealed depth‐related variations in their population structure. Length‐frequency analyses are presented for M. carinatus and D. eleginoides and show a tendency for larger individuals to inhabit deeper water. Discard rates from the commercial catch were sometimes high, particularly for the smaller species, raising concerns about the impact of a fishery on by‐catch species. The potential for deep‐sea fisheries in Falkland waters is discussed and further studies are suggested in the light of developing oil, gas and fishing industries. The presence of some invertebrate taxa is recorded.
From the biology of the individual to the dynamics of the population: bridging the gap in fish early life studies
Authors: Heath M. , Gallego A.
Published: June 2006

The mean properties of larval fish populations do not necessarily reflect the properties of the mean individual. For example, the change in mean length in a population with time may not reflect the average individual growth rate, since individual growth rates and survival probability are linked so that slow growing individuals suffer higher mortality. Hence, mean growth rate indicated from population data could be biased upwards. Factors which influence the magnitude and variability of individual growth rates can exert nonlinear effects on population survival. Two categories of process must be considered: first, the variability in exposure of the average individual as a consequence of individual variability in dispersal through a patchy environment; and second, the intrinsic variability between individuals expressed even under equal exposure conditions. These two aspects have been addressed independently, the first by lagrangian modelling of individual fish larvae linked to spatially resolved hydrodynamic models, and the second by strategic biological modelling. In this paper, progress towards the goal of individually based larval fish ecosystem models is reviewed, highlighting the space and time scales which may be important in such systems, and identifying the gaps in current knowledge of larval biology.
Does the western Irish Sea gyre influence the distribution of pelagic juvenile fish?
Authors: Dickey‐Collas M. , Brown J. , Fernand L. , Hill A. E. , Horsburgh K. J. , Garvine R. W.
Published: June 2006

The western Irish Sea is an important spawning and nursery ground for many commercially exploited fish. Spawning begins in the Irish coastal regions in early spring, and moves offshore as the season develops. As a result of the onset of seasonal heating in spring, stratification isolates a dome of cold bottom winter water in the deep (>100 m) basin of the western Irish Sea. The resultant density fields drive a cyclonic gyre which dominates the circulation of the region during late spring and summer and is characterized by anticlockwise current speeds which exceed 0.2 ms–1, after removal of tides. Surveys of pelagic juvenile (0‐group) fish in 1994, 1995 and 1996, showed that they were coincident with the centre of the gyre. Physical data from 1994 and 1995, were used to describe the horizontal and vertical structure of the water column and the associated circulation regime. The behaviour and swimming speeds of pelagic juvenile fish were insufficient to explain their apparent shift in abundance away from the coast to the central western Irish Sea. Drifter and current data suggested that their entrainment into the gyre could provide both the transport and retention mechanisms.
Nucleic acids in ichthyoplankton ecology: a review, with emphasis on recent advances for new perspectives
Authors: Bergeron J.‐P.
Published: June 2006

Nucleic acid assessments and especially the RNA/DNA ratio are used widely as indices of growth rate or nutritional condition of larval fish. Methodological aspects are considered with the aim of defining a most reliable analytical procedure. Laboratory calibrations can give conflicting results, but general and common features may be drawn from a global examination. A high variability of RNA content, and thus RNA/DNA ratio, was revealed by estimates at the individual level and seems to be more related to feeding condition in late larval or juvenile stages than in yolk‐sac and first‐feeding larvae. An alternative is suggested, based on the relative DNA content which appears more stable and sensitive to starvation during these early stages. The consistency of such a pattern is strongly supported by findings about regulation of ribosomal RNA content of tissues, and especially white muscle, by nutrition. Determination of a threshold founded on a simple observation of morphological development stages is proposed as a base to define the best way to assess the larval nutritional condition. Some field applications are reviewed briefly. Finally an appraisal of the advantages and drawbacks of the different nucleic acid‐based indices is attempted, which permits delineation of some prospects for future research.
Seasonal and long‐term changes in biometrics of eel larvae: a possible relationship between recruitment variation and North Atlantic ecosystem productivity
Authors: Desaunay Y. , Guerault D.
Published: June 2006

The European eel larval life has two stages: the oceanic leptocephalus, in which growth is dependent on food supply, and the metamorphosis glass eel stage, in which feeding and growth are stopped until immigration in estuarine waters. Data from fisheries and experimental surveys in European estuaries at different periods between the 1930s and the 1990s showed a simultaneous decrease of mean length and abundance level. A monthly survey at the Vilaine estuary (Bay of Biscay) during 2 years provided a periodical model of seasonal variation in length and weight of newly recruited glass eels. Otolith microstructure was used to back‐calculate larval stage durations and the timing of transatlantic migration. Glass eels entering the estuary in autumn are longer and more numerous than those arriving in summer. They migrated across the ocean during spring and summer, seasons when plankton production is likely to reach maximum levels. The proposed hypothesis regarding the determinism of recruitment in the eel, on the seasonal and on the yearly range, is that leptocephalus growth and glass eel survival are partly dependent on the plankton production at the oceanic scale. Eel recruitment dynamics could provide an integrated figure of large‐scale environment fluctuations.
Ontogenic migration of Pleuronectes flesus larvae in the eastern English Channel
Authors: Grioche A. , Koubbi P. , Sautour B.
Published: June 2006

Along the French coast of the eastern English Channel there is a strong separation in the hydrology, zooplankton community and ichthyoplankton assemblages, between a coastal ecosystem of continental influence and an offshore ecosystem of Atlantic influence. During April and May 1995, two surveys (60 stations) were conducted to describe the early life history of fishes in this area, and especially the influence of hydrodynamics on Pleuronectes flesus larval transfer from the spawning grounds to the nurseries. Ontogenic changes in larval distributions were described by variograms and path analysis. P. flesus eggs and young larvae were found in the southern offshore area. Their distributions were mainly influenced by sediment and cold temperature found in the central part of the Channel. Older larvae were found at more northern stations, showing a clumped distribution near estuaries, in areas of low salinity. Apparently, young stages of this species were transported from the south central spawning area to coastal waters by residual currents. Behavioural changes in older larvae facilitate the move to nurseries along the French coast.
‘A Place of Our Own'? Teenage Mothers’ Views on Housing Needs and Support Models
Authors: Cooke Jo , Owen Jenny
Published: June 2006

Since 2003, government policy has required local authorities to provide support when they house lone teenage parents seeking accommodation. This qualitative study addresses young mothers’ routes into housing need and their experiences of housing access and support, drawing on interview and focus group data collected in 2003. The findings emphasise mothers’ preferences for forms of support which facilitate moves towards increased choice and independence. Reinforcing messages from other research, these findings also show a gap between concepts of ‘support’ embodied in government policy and those which inform practice, within agencies and among young people. © 2006 The Author(s). Journal compilation Copyright © 2006 National Children's Bureau.
HUMIDITY SYSTEM OF DRYING TERRA COTTA1
Authors: Ortman F. B. , Davis H. E.
Published: June 2006

A brief discussion of the theory of humidity drying is followed by a description of the construction and operation of a five room dryer installed above a tunnel kiln and supplied with automatic temp. and humidity control and air circulation. As compared with the older system having controlled air circulation only, the new dryer has been found to have the following advantages: (1) Reduced steam consumption; (2) 50% reduction in floor space; (3) 50% reduction in drying time; (4) Reduction in labor costs owing to elimination of a second handling of incompletely dried pieces; (5) Reduced losses from cracking and warping.
VARIATION IN HEAT TREATMENT OF A SILICA BRICK IN THE CROWN OF A TUNNEL KILN1
Authors: Klein A. A. , Ramsdell L. S.
Published: June 2006

It is possible through microscopic investigation of a silica brick to ascertain approximately the heat treatment to which it has been subjected. In this way the temperature difference between the inner and outer ends of a silica brick which had seen service in the arch of a Dressler tunnel kiln was estimated to be at least 200°.
THE APPLICATION OF HEAT IN CERAMICS
Authors: Pitz‐Gerald Gerald
Published: June 2006

After discussing the relation of draft to heat transfer and kiln dimensions the conclusion is reached that the higher the flame temperature in the kiln the more economical will be the firing operation, and that a combination of natural and mechanical draft makes an ideal installation.
THE PRODUCTION OF SOME WHITE ENAMELS FOR COPPER1
Authors: Danielson R. R. , Reinecker H. P.
Published: June 2006

The investigation deals with the development of some white enamels for copper watch dials, thermometer scale plates, and signs. The effect of varying Na2O, PbO, cryolite, SiO2 and B2O3 on the properties of the enamels was studied in twenty enamel compositions. The following conclusions were reached: (1) Correct melting is extremely important in the preparation of copper enamels; (a) Slow air cooling of the frit is preferable to quenching in water. (b) Repeated melting tends to promote opacity and to eliminate dissolved gases. (2) A somewhat reducing atmosphere during firing avoids oxidation of the copper. (3) Slight changes in enamel composition have a decided effect on the resultant properties. (4) Sodium oxide promotes gloss but reduces opacity very decidedly. (5) Lead oxide promotes fusibility without materially reducing opacity, except by dilution. (6) Cryolite is not a desirable flux or opacifier as it tends to develop a matt finish. (7) It is desirable to keep the boric oxide content low and good enamels may be produced without it. (8) By using “white arsenic” as an opacifier tin oxide is unnecessary. (9) The following were the best enamels obtained and these appear to be equal to a number of watch dial enamels examined: C‐19 and C‐20. 20. (10) A second group of compositions which appear to promote results equal to those in use for thermometer scales, advertising letters, etc., are C‐10. 10. C‐21, C‐22, and C‐24. In selecting these compositions, all factors such as opacity, gloss, texture, fit and resistance to attack of copper have been considered.
AN OXYGEN‐ACETYLENE HIGH‐TEMPERATURE FURNACE1
Authors: Wilson Hewitt
Published: June 2006

A detailed description, with drawing, is given to show the use of oxy‐acetylene gas in a small furnace for using refractory cones. The advantages claimed, are (1) simplicity of construction, operation and repair; (2) ease of control; (3) high temperatures obtainable; (4) oxidizing atmosphere; (5) comfortable working conditions, owing to the small volume of hot combustion gases; and (6) portable character of the furnace, fuel and firing apparatus, permitting its use in localities where gas or electricity can not be obtained, such as in the field or at the mine. The following change is suggested in the Ceramic Society's specified rate of heating for cone fusion tests. “The rate of heating shall not exceed that corresponding to one‐half a cone (approximately 10 degrees C) per minute within a range of ten cones below that of the final fusion cone and this rate shall preferably be decreased to one cone per five minutes within two cones of the final cone of fusion.”
POSSIBILITIES OF TERRA COTTA CASTING
Authors: Geller R. F.
Published: June 2006

Experimental method.—The casting properties, viscosity, specific gravity and drying behavior of three kaolins, two ball clays, one fire‐clay and four representative commercial bodies, together with terra cotta clays, were studied. The clays and bodies were treated with varying amounts of salts and cast in the form of small ashlars.

Conclusions.—Kaolins have an open structure but do not develop strength on drying. Bonding properties are furnished by ball clays which, however, tend to seal against the mold. Commercial terra cotta bodies tested do not possess good casting properties but can be modified through a study of the component clays. Mechanical difficulties attending the casting of terra cotta render the feasibility of the process doubtful at the present time.
NOTE ON THE HARDNESS OF GLAZES1
Authors: Blumenthal George
Published: June 2006

Method of measurement.—The apparatus used (figure 1) consisted of a hardened tungsten‐steel point which was allowed to bear on the glaze surface for 3 min. under a pressure of 50 lbs. The hardness was then computed from the dimensions of the resulting indentation. Results were reproducible to about 5 per cent. (See table III.) The presence of ridges and bubbles in the glaze was the principal cause of discordant readings.

Results and conclusions.—The enamels show the lowest and the porcelain glazes the greatest hardness, while the whiteware glazes occupy an intermediate position. The difference in hardness between the enamels and the whiteware glazes is quite marked. There is also a rather well defined difference between the whiteware and the porcelain glazes, but not a sharp separation between the lower and the higher fired porcelain glazes. Enough evidence has been accumulated to show that increased firing of the same glaze will increase the hardness. It appears also that increase in the alumina content brings about greater hardness.
A STUDY OF SOME BOND CLAY MIXTURES1
Authors: Fuller D. H.
Published: June 2006

In order to determine whether as good results could be obtained from mixtures of American clays as from the Gross Almerode clay in glass pot bodies, two American ball clays were combined in various proportions with two silicious American bond clays and compared with the Gross Almerode clay in bodies containing 50% grog. Physical properties and resistance to glass batch corrosion were determined. It was not found possible to duplicate the physical properties, especially the low water of plasticity and low drying shrinkage of the Gross Almerode body but several of the bodies gave better results as regards resistance to corrosion than the one containing the Gross Almerode clay. In general it was concluded that it is possible by blending American clays to produce a body equal or superior to the Gross Almerode body. More thorough heat treatment of pots or tank blocks in the arches and greater uniformity in temperature during the burning is required.
A STUDY OF THE HEATING AND COOLING CURVES OF JAPANESE KAOLINITE
Authors: Satoh S.
Published: June 2006

Effect of heating Japanese kaolinite at 100° to 1400° C for 3 to 4 hours.—Ignition loss of weight Was found to occur chiefly between 400° and 600°C, the rate of increase per degree reaching a maximum at about 460 °C. Changes of microstructure were observed at 600°, 900–1000°, 1250–1300° and at 1400 °C, when sillimanite began to develop.

Heating and cooling curves for Japanese kaolinite, to 1400°C.—A differential method was used with quartz sand as the comparison substance. In addition to the known reactions: (1) an endothermic from 450° to 700°, and (2) an exothermic near 950°, (3) an exothermic change between 1200° and 1300° was discovered, and it was observed that the endothermic reaction seems to include two periods of heat absorption, (1a) 450° to 650° and (1b) 650° to 700°. In explanation, the author suggests that 1a is due to dehydration, 1b to dissociation of kaolinite into free alumina and free silica, 2 to a polymerization of the alumia and 3 to the formation of amorphous sillimanite. In the discussion, E. W. Washburn calls attention to the fact that the author has neglected the endothermic reaction of quartz at 575 °C and suggests that some of his conclusions are therefore erroneous.

Heating and cooling curves for alumina obtained from the nitrate, hydroxide and sulfate by calcination are given in figure 6. Exothermic reactions which are ascribed by the author to polymerization of alumia occur at 800° to 900° and at 1100° to 1200° instead of at 950° and at 1250° as in the case of kaolinite.
TESTS OF FIRE‐BRICK MADE FROM GANISTER, FLINT CLAY, AND PLASTIC CLAY MIXTURES, WITH SPECIAL REFERENCE TO SPALLING1
Authors: Howe Raymond M. , Sheppard Mark
Published: June 2006

Influence of the alumina‐silica ratio on properties of fire‐brick.—Five experimental batches of fire‐brick were made by mixing various proportions of ganister, flint clay and plastic clay in such a way as to vary the silica content from 53 to 77 per cent and the alumina content from 43 to 20 per cent. (1) The fusion points were found only slightly lower than those of corresponding pure silica‐alumina mixtures. (2) Load tests at high temperature showed that the behavior under compression does not depend on chemical composition so much as on other factors such as the temperature of burning. (3) The resistance to spalling, as tested by alternate heating and dipping in cold water, was found to decrease as the temperature of burning was increased from 1300° to 1400 °C. The higher silica bricks were relatively more resistant at the lower temperature but not so at 1400 °C. Therefore the substitution of ganister for flint clay increases the resistance to spalling at moderate operating temperatures but is of no advantage at 1400° or above.
THE METALLOGRAPHY OF THE OXY‐ACETYLENE WELD AS AFFECTED BY ENAMELING1
Authors: Poste E. P.
Published: June 2006

Metallography of Low Carbon Steel.—A discussion of the cooling of steel through the critical range is followed by a consideration of the general structure of low carbon material. A brief discussion of mechanical and thermal treatments follows including the statement of the essential conditions for annealing.

Investigation of Oxy‐Acetylene Welds.—The temperature reached by the steel in the enameling operation is discussed with reference to the annealing temperature. An examination of plates and welds before and after enameling shows that a thorough annealing of the weld has been accomplished.
THE SEPARATION OF LIME FROM DOLOMITE1
Authors: Schurecht H. G.
Published: June 2006

Calcination.—Magne ium carbonate in dolomite is decomposed by calcining for one hour at 800°C. Calcium carbonate is not completely decomposed until after calcination at 960°‐1040°C for one hour.

Treatment with sulphuric acid.—By adding sufficient H2SO4 to milk of dolomite to react with the lime present, a bulky precipitate of Mg(OH)2 is formed which may be partially separated from the finer CaSO4 by screening through a 120 mesh sieve. The residue on the screen contains about 68.3 per cent MgO and represents over 50 per cent of the original CaMgO.

Flotation.—The best results by flotation were obtained by removing the fine material from the raw dolomite and then calcining at 920°C. Wood creosote flotation oil number 400 was found best suited for this separation. The concentrates removed by flotation, however, represent only 25 per cent of the dolomite originally treated.

Leaching and screening.—By a leaching and screening treatment it is possible to obtain a product containing about 80 per cent MgO. This is superior to Canadian magnesite in MgO content.

Elutriation.—By an elutriation treatment it is possible to obtain a residue containing over 85 per cent MgO and representing about 30 per cent of the, original dolomite.
DESIGN OF A FURNACE FOR ANNEALING OPTICAL GLASS1
Authors: Sharp Donald E.
Published: June 2006

Design of a natural‐gas furnace for annealing optical glass.—Most of the furnaces built for annealing regular glassware are unsuitable for optical glass due to irregularity and inequality of temperatures. Working drawings are given for a successful optical glass annealing furnace operated by natural gas. The design is novel in the placing of the flues and burners in such a manner as to supply the heat and remove it in a symmetrical manner, thus obtaining uniformity of temperature.
THE TRANSVERSE STRENGTH OF FIRE‐CLAY TILES AT FURNACE TEMPERATURES1
Authors: Geller R. F.
Published: June 2006

Commercial fire‐clay tiles, were tested at furnace temperatures, for transverse strength. This was supplemented by tests of tiles of known composition made in the laboratory. Moduli of rupture obtained varied from 245.5 pounds per square inch at 1275°C, to 28.9 pounds per square inch at 1350°C but the data collected do not warrant definite conclusions.
THE CAUSES AND CONTROL OF FISH SCALING OF ENAMELS FOR SHEET IRON AND STEEL1
Authors: Danielson R. R. , Souder W. H.
Published: June 2006

Data obtained.—This paper presents measurements of the following factors and properties and their influences upon fish scaling in the case of typical single and three‐coat enamels: time and temp. during melting of the frit; fusibility of the enamel; coeff. of expansion of the enamel, and of a variety of representative irons and steels up to 500°C (accuracy about 0.1%); annealing the enamel coat after firing; chem. comp. of the steels and irons; mechanical treatment (rolling, spinning, drawing, and so forth of the stock; microscopic surface structure of the stock; effect of chem. comp. upon thermal expansion of enamel.

Incidentally it was found that the formulas of Mayer and Havas for computing the thermal expansion of enamel from its chem. comp. can not be relied upon:

Conclusions.—On the basis of these exhaustive tests, the following conclusions have been drawn as to the causes and the control of fish scaling.

(A) Causes.—1. The cause of fish scaling lies in the difference of the coefficients of expansion of the enamel and the stock, that for steel being higher than for enamels so that the latter are under a compressive stress. The factors influencing this phenomenon are as follows: (a) Composition of the enamel as affecting the coefficient of expansion of the enamel; (b) Overfiring—thus volatilizing those substances which tend to keep the coefficient high; (c) Lack of annealing enameled ware, the enamel coating of which is a glass and should logically be treated as such.

2. Fish scaling is due secondarily to a number of factors which may affect the strength of the enamel or its adherence to the metal. (a) The physical condition of the surface of the metal as influenced by drawing, spinning, cold rolling or other mechanical treatment; (b) Composition of the glass as affecting its elastic strength; (c) Underfiring, enamel not fused to metals; (d) Cleanliness of the surface as regards removal of drawing compounds, grease, etc.

(B) Remedies.—1. (a) Adjusting the composition of the enamel so as to increase its coefficient, e. g., by decreasing the boric acid content; (b) Correct firing of the enamel to avoid unnecessary volatilization of such fluxes as soda and cryolite; 2. (a) Adjusting enamel composition to increase its strength; (b) Correct firing to give proper adherence. 3. Treatment of metal to give best adhesion by (a) cold rolling or other suitable mechanical treatment of the untreated steel; (b) thorough cleaning.

(C) Summary.—Broadly stated, then, fish scaling can be absolutely controlled by one or all of the following methods: (1) By the development of an enamel with an expansion fitting the metal; (2) by annealing the enameled ware; (3) by treatment of the metal as cold rolling or some other method of working: (4) by developing an enamel with a wide range of compressional elasticity and applying this enamel to metal treated as indicated above.
CONTINUOUS TUNNEL KILNS AT THE PLANT OF MOUNT CLEMENS POTTERY COMPANY1,2
Authors: Harrop C. B.
Published: June 2006

These two direct‐fired kilns (bisque and glost) are placed end to end in a specially constructed kiln building 825 feet long. Both kilns are fired with soft coal, hand stoked. Three motors are required, aggregating 8/14 horsepower on each kiln. Hydraulic car pushers are employed. A pressure of 8100 lbs. is required to move the 44 cars thru the bisque kiln. The bisque kiln cars hold 278 dozen ware each and at a 55‐minute car schedule, deliver over 7200 dozen ware per 24 hours at a fuel saving of more than 85% over the former periodic kiln operating at this plant. This bisque capacity is equivalent to that of thirteen 16/12 ft. diameter periodic kilns which would cost more to build than the bisque tunnel kiln.
A TERRA COTTA INDUSTRY FOR OHIO1
Authors: Watts Arthur S.
Published: June 2006

Two terra cotta industries using Ohio clays existed in Ohio prior to 1860. Today no terra cotta industries exist within the State, although Ohio has the clay, fuel and skilled labor. One Ohio clay, the Tionesta or No. 3 B, is especially adapted for terra cotta. It crosses the state through Vinton, Hocking, Perry, Muskingum, Coshocton, Tuscrawas and Stark Counties.

The occurrences and chemical composition as determined by the Ohio Geol. Survey are given by the author.

This clay burns with a shrinkage of about 6 per cent and a porosity of about 8 per cent from cone 2 to cone 5 with practically no color variation. It will carry its own weight of non‐plastic without serious loss of mechanical strength.

Successful combinations and working directions for body, engobe, glaze and vitreous slip are given.
A STUDY OF THE OPERATION OF A DRESSLER TUNNEL KILN1
Authors: Hudson Charles J.
Published: June 2006

Before installing a Dressler tunnel kiln, Norton Company made a study of an existing kiln. At Steubenville, Ohio, the kiln was found to be working well; repairs were small, economy in fuel, labor and firing time had resulted. The heat distribution was found to be variable but subject to control. The amount of rejected ware was very small and in no case could it be charged definitely to the kiln.
REFRACTORIES UNDER LOAD CONDITIONS1
Authors: Knollman H. J.
Published: June 2006

Life factors.—The life of fire clay slabs, rings and saggers is influenced by a number of factors, both mechanical and chemical. The chief factors controlling the life of the slabs are (1) proper selections of clays and grog, (2) medium absorption or porosity, (3) strength in the unburned state, (4) proper and thorough blending and preparation of the mix, (5) proper pressing so as to insure freedom from flaws, (6) proper drying, (7) proper setting in the kilns and especially (8) initial burn. These factors are briefly discussed.

Setting.—The manner of setting grinding wheels, using large slabs is described. This manner of setting causes transverse bending stress to be set up in the slab and shear stresses to develop. This shearing force, in connection with the large size and the high temperature (cones 11 to 12), make severe conditions for the slab to withstand.

Shape and size.—The rate of heating and the size and shape of the slabs are additional factors. Round slabs, up to about 20° in diameter have a decidedly longer life when made in two half sections as compared with the solid shape. Larger slabs have longest life when split up into four sections, while if solid they will fail in one burn. Warping of the slabs, as well as cracking, causes failure. In general, if the width of area of the load is held constant, and length of span of the slab is increased, deformation and cracking is slightly increased. If the span is held constant, and the width or load area is increased warpage is greatly increased, especially as the number of burns under load increases. Cracking also increases in direct proportion to increase in width. These features are more pronounced the longer the span.

Ultimate failure at high temperatures.—When not due to structural defects, failure is brought about by a gradual decrease in mechanical strength from burn to burn, so that fire‐clay slabs under transverse load at such temperatures have decided limitations
A COMPARATIVE STUDY OF AMERICAN AND GERMAN QUARTZITES AS RAW MATERIALS FOR THE SILICA BRICK INDUSTRY1
Authors: Endell K.
Published: June 2006

Properties determined.—Chemical composition, cone fusion temperatures, micro‐structure in the raw state and after successive firings, and velocity of inversion on successive firings.

Comparative burning behaviors.—After a single firing to 1435°C the German erratic block quartzites of the tertiary age show a much greater expansion than the American quartzites. Hessian quartzite resembles the American.

Advantages of the German quartzites.—The use of the German erratic block quartzites for the manufacturing of silica brick of the highest quality is the more economical, both in preparation and burning costs, as compared with the American quartzites.
POROSITY: III. WATER AS AN ABSORPTION LIQUID
Authors: Washburn Edward W. , Fooyitt Frank F.
Published: June 2006

Classes of absorption method.—The ordinary immersion method has been shown by previous investigators to be unreliable. Simple immersion in low vacuo without boiling is also shown theoretically to be unreliable. An analysis of the results of previous investigators indicates the presence of unsuspected sources of error.

Effect of adsorbed gases upon dry weights of test pieces.—Dry air is shown to be without appreciable influence. Depending upon the humidity of the atmosphere, adsorbed water vapor may cause errors up to 2 per cent in the porosity value. Perfectly dry fired clay will remove water from conc. H2SO4, and from fused CaCl2.

Saturation by boiling at atmospheric pressure.—A one hour's (and in one instance a 5 hours') boiling failed to saturate completely. On continued boiling the saturated weight increases linearly with the time and this in spite of the fact that appreciable quantities of dissolved materials are removed from the test piece by the hot water. This result is shown to be due to a gradual and continuous rehydration of the clay by the hot water. The error from this factor may amount to as much as 3% and the error from dissolved materials to as much as 2%, during a 3 hours' boiling. The nature of the dissolved material was determined.

Method of cooling the test piece.—It is recommended that the test piece be kept in a closed vessel over 95% sulphuric acid for several hours before its dry weight is taken.

Saturation procedure.—A vacuum method is described in which water may be employed as the saturation liquid under conditions where the above sources of error are reduced to a minimum. The method is not however recommended as a primary standard.

Necessity of a soaking period.—It is shown from theoretical considerations that a soaking period is necessary and methods are given for calculating and for measuring the minimum soaking period required for a given test piece and a given liquid of known penetrativity.
POROSITY IV: THE USE OF PETROLEUM PRODUCTS AS ABSORPTION LIQUIDS
Authors: Washburn Edward W. , Bunting Elmer N.
Published: June 2006

Advantages of petroleum products.—‐Avoidance of: slaking, chemical reaction, adsorption, and solvent action; but longer soaking time is required.

Paraffine and vaseline.—‐Materials having high fluidity when hot, and comparatively low fluidity when cold, permit surface of saturated test piece to be brought to definite and reproducible condition with all surface pores full. Paraffine may be used but vaseline is preferable because it undergoes no change of phase on cooling.

Procedure and results.—‐A saturation procedure is described and comparative results given.

Density and penetrativity of vaseline.—‐Sp. gr.23°/4° 0.8730, 32°/4° 0.8684, 42°/4° 0.8624. Penetrativity between 100° and 200°C = 0.063 (t— 30)2 cms./sec. A penetratimeter for determining the penetrativity of liquids is described
EARTHENWARE BODIES AND GLAZES1
Authors: Sortwell H. H.
Published: June 2006

Effect of body composition on crazing.—‐Six bodies of each of 2 standard clay compositions were prepared with variable clay and flint content and after biscuiting at cone 8 were glazed with 21 earthenware glazes and glost fired at cones 4 and 6. The results indicated that the variability of the silica content of clays would not be great enough to produce crazing in a well‐balanced glaze.

Effect of proportion and composition of frit.—‐A standard whiteware glaze was compounded in 6 different ways and several other glazes in 2 ways. It was found that the method of compounding had no effect on crazing but it affected the gloss and fusibility. Increase in the percentage of material fritted increased the gloss and fusibility. With the same percentage of frit the best glost and highest fusibility were obtained when the flint and part of the clay were included in the frit.

Effect of some variations in glaze composition.—‐Substitution of CaO by Na2O, pound for pound, as well as direct addition of Na2O, increased crazing, improved gloss and increased the fusibility. Direct addition of feldspar increased crazing slightly and diminished gloss, but did not noticeably affect the fusibility. Substitution of 1½1/2 parts of feldspar for one part of flint to maintain the same fusibility increased crazing and diminished gloss. Direct addition of CaO improved gloss, increased fusibility and slightly reduced crazing.
THE MANUFACTURE AND TREATMENT OF GLASS MELTING POTS*
Authors: Brownlee W. K. , Gorton A. F.
Published: June 2006

Manufacture of glass melting pots.—The raw materials used, the methods of grinding and mixing the raw clay and grog, and the way in which pots are built and dried are briefly described for the purpose of impressing glass makers with the amount of labor and care involved. At present only one grade of pot is made; but the difficulty of getting a pot suitable for all kinds of glass suggests the desirability of making special grades of pot for use with specified kinds of glass.

Proper treatment of pots by the glass maker.—The authors emphasize the importance of gently handling pots and of storing them in a warm and dry place. The precautions to be taken in preheating pots in arches are discussed at length for this is the critical period in the life of the pot. The batch should be properly crushed and mixed and should either be preheated or loaded in gradually; and the furnace temperature should be carefully regulated. It is particularly urged that the technical treatment of pots in the glass be entrusted to a man trained in ceramics and physical chemistry.

Arches for heating glass melting pots.—After discussing the usual design the authors suggest improvements as to fire box locations, construction of walls and door, etc.
THE “WHY” OF AGEING CLAY1
Authors: Spurrier H.
Published: June 2006

Ageing of clay.—(1) Evolution of CO2 was found to continue for over 34 days after pugging and, like the change of plasticity, to proceed more rapidly between 80° and 90° F than below 60°. (2) Effect of replacing water by non‐aqueous liquids was to inhibit the development of plasticity altogether. (3) Effect of a dilute solution of H2O2 was to produce a pronounced increase of viscosity and also to stimulate the growth of filaments algae and the consequent evolution of both CO and CO2. It seems probable, therefore, that the change of plasticity of clays with time is due, in some way, to the growth of such algae. (4) This algae theory would explain all the effects found.

New chemical measure of the plasticity of clays.—The ratio of the amounts of Al2O3 and SiO2 dissolved by caustic potash was found, for the three clays tested (Cooley Ball, Edgar Plastic Kaolin and Harris Spruce Pine), to decrease rapidly with diminishing plasticity and therefore might well be used as a quantitative measure of plasticity.
EXPERIMENTS IN DEAD‐BURNING DOLOMITE AND MAGNESITE1
Authors: Schurecht H. G.
Published: June 2006

Stability of calcined dolomite; effect of fineness of raw material, nature of flux and temperature of burning.—Dolomite is difficult to dead‐burn because the absorption of moisture from the air produces a gradual slacking due, probably, to the hydration of lime and various lime compounds, and this tends to cause disintegration. With all the fluxes tried, 100 mesh raw material gave greater resistance to slacking than 8 mesh size. This resistance decreased, however, with increasing temperature of calcining, by an amount which seems to depend on the silica and alumina content of the flux, being greatest for basic open hearth slag and kaolin, less for flue dust, and iron ore, and least for roll scale. The stability also varied with the proportions of flux used, being greater, as a rule, for smaller proportions.

Shrinkage, porosity and vitrification of calcined dolomite; effect of flux and burning temperature.—The shrinkage and porosity curves for mixtures containing flue dust, iron ore or roll scale are very similar. The higher the proportion of flux, the lower the temperature required to get maximum shrinkage and minimum porosity. Kaolin and basic open hearth slag behaved peculiarly in that vitrification depended more on the burning temperature than on the proportion of flux used.

Experiments in making dolomite brick.—It was found that ageing of the wet calcined material was necessary to prevent cracking of the bricks upon drying. With 5 per cent MgCl2 as binder, comparatively strong brick were obtained. High shrinkage on firing caused excessive cracking, but the bricks were extremely dense and did not disintegrate until after four to six months. Unfired tar‐bonded brick were made with sufficient strength to stand shipping and with a storage life of about four months. Fired tar‐bonded brick showed less shrinkage and cracking than similar brick made with water. If dipped in tar to protect them from moisture, such brick will last five or six months before disintegration. It is possible, then to make dolomite brick with a storage life long enough to allow shipping and placing in furnaces.

Stability, shrinkage and porosity of calcined magnesite; effect of flux and temperature of burning.—Unlike dolomite, magnesite showed less slacking effect the higher the temperature of burning. Roll scale gave greater stability than iron ore, probably because of its lower silica content. The product was comparatively porous and with low shrinkage, even with high proportions of roll scale.
NOTE ON SAGGER CLAY PREPARATION1
Authors: Pence F. K.
Published: June 2006

Better mixture of ingredients.—Saggers can be improved in quality by installing a mixing machine immediately following the dry pan. The soaking pit may then be eliminated and the clay and water fed directly to the pug mill. This process permits of large tonnage and is of course also applicable to other bodies.
THE ABSORPTION OF SODIUM HYDROXIDE BY KAOLINS1
Authors: Geller R. F. , Caldwell D. R.
Published: June 2006

Amounts of NaOH absorbed by kaolins.—The amounts of sodium hydroxide completely absorbed by North Carolina, Georgia and Florida kaolins, without showing the presence of free alkali sufficient to color phenolphthalein are, respectively: 0.125%; between 0.100% and 0.125%; and between 0.225% and 0.250% of the dry weight of the clay.

Effect of time and temperature on absorption.—The absorption appears to be largely independent of time but increases with temperature.

Nature of the absorption process.—The experimental data can be expressed by the Freundlich adsorption isotherm thus indicating that the adsorption process belongs to the category of adsorption phenomena.
TYPES OF GLAZES SUITABLE FOR DECORATIVE INLAY PROCESSES
Authors: Rhead Frederick H.
Published: June 2006

A definition of the inlay process is given. Type of outlines and method of application are discussed. Glaze formulas in present use are noted, and general conditions necessary for the successful execution of this process are outlined.
THE EVOLUTION AND DEVELOPMENT OF GLASS HOUSE EQUIPMENT
Authors: Herzog J. S.
Published: June 2006

This paper is an account of the evolution of machinery used in glass‐making in which the modern methods are contrasted with the old. Gas producers, gas burners and oil burners are discussed. In burning gas a greater efficiency obtains when the air entirely surrounds the gas stream as it enters the fire box. In burning oil the high pressure costs more for installation but is more efficient. The tendency is towards automatic machinery for all glass‐making operations. Many machines are well nigh perfect but improvements are being made constantly. Mention is made of the need of a better alloy for metal molds. In the glass industry labor represents on the average 40 per cent of the cost of the product. In this respect the glass industry ranks thirteenth.
A NEW TYPE OF GAS‐FIRED VITREOUS ENAMELING FURNACE
Authors: Clark H. H.
Published: June 2006

The furnace described in this article has a working chamber 4 feet wide by 3 feet high by 10 feet long, and is heated by ten gas burners, five on each side. Other proportions are made to suit the nature of the work to be enameled. City gas is most desirable, although any gas above the grade of producer gas may be used.

A furnace of this type can be brought to a working temperature in less than an hour, and will turn out from 12 to 24 loads of work an hour, depending on the kind of work being enameled.

The average gas consumption is about 1800 cubic feet of 500 B.t.u. gas per hour when firing about 600 square feet of flat ware totaling 690 pounds, representing 240 pieces, at an average temperature of 1700°F. The furnace runs without attention other than that given by the men who load and unload the fork.

Furnaces of the intermittent type have various features which arc covered by patents issued and applied for. In addition to fuel economy, this type of furnace has the added advantage of producing ware of a very high gloss.

The first cost is low and no foundations other than the ordinary cement floor are necessary, as the entire furnace is above the floor level. Maintenance is practically nothing, as there is no muffle or combustion chamber.
SOME PROPERTIES OF ZINC OXIDE BODIES1
Authors: Libman Earl E.
Published: June 2006

Melting Point of ZnO.—The melting point of ZnO is above 1800° C and may be above its normal sublimation point.

Volume Shrinkage and Porosity of ZnO Bodies.—A very hard and dense body composed of pure ZnO can be prepared. At high temperatures it exhibits the unusual phenomenon of volume shrinkage accompanied by an increasing porosity.

Zinc Retort Bodies.—In the discussion the possible advantages of incorporating zinc oxide in a zinc retort body are mentioned.
THE CONTROL OF GLAZE‐FIT BY MEANS OF TENSILE TEST SPECIMENS1
Authors: Riddle F. H. , Laird J. S.
Published: June 2006

The selection of a suitable glaze for a particular body by usual inspection of a field of glaze trials is not sufficiently precise, and gives no indication of slow crazing tendencies.

A new method of selecting glazes depends on the effect of a glaze on the strength of a porcelain tensile test specimen. The best fitting glazes increase the strength while poorer ones decrease it. Glazes which craze weaken the specimens very markedly. Results obtained with various glazes on one fire porcelain are given.