Enameled Iron Research Articles

Method for Qualitative and Quantitative Analysis of Ancient Lead Enamel Using Laser Inducted Breakdown Spectroscopy

The method of laser induced breakdown spectroscopy (LIBS) was used in analysis of the archaeological enamel samples from the ancient settlement of Jochi Khan (XIV century). During the qualitative analysis, it was found that the elements of the enamel matrix are Si, Pb, K, Na, Mg, Ca, Al. The glaze color is due to the presence of copper and iron. Clustering by the k-means method revealed two groups of samples similar in composition of enamel, but differing in place of origin within the settlement. For the studied samples the semi-quantitative composition of glazes was established from the spectra of LIBS using a method based on the hypothesis of local thermodynamic equilibrium (LTE) and a chemometric approach (Projection to Latent Structures, PLS). Probabilistic deterministic design of experiment was used to search for pairs of element lines that are not subject to changes when the conditions for spectra registration vary, and to determine the coefficients in the equations based on LTR. Calculations using the PLC method were carried out in the “R” programming environment. The following content of the matrix elements was obtained in terms of the most stable oxides, %: SiO2 — 49–61, PbO — 23–31, MgO — 1.7–2.3, CaO — 4.6–6.9, Na2O — 4.1–5.3, K2O — 5.1–6.4, Al2O3 — 0.8–1.7, CuO — 0.32–0.4, Fe2O3 — 0.09–0.16. The results of both methods are generally consistent with each other. The inaccuracy between 4 parallel determinations were 15-24 % for LTE, and 9–14 % for PLS. Taking into account the data of semi-quantitative analysis, it was concluded that the division into two groups is based on a different ratio of copper and iron in enamel.

The Power of Inclusion in Donald Judd’s Art: Observations by an Artist

Donald Judd, Untitled, 1962, cadmium red light oil on wood with black enameled iron pipe, 481⁄16 x 331⁄16 x 21½ in. (121.5 x 83.5 x 55.5 cm), exhibition view, Sculpture on the Move 1946–2016, Kunst...

Thermal Natural Convection Analysis of Olive Oil in Different Cookware Materials for Induction Stoves

Abstract This manuscript describes the analysis of temperature and the distribution of natural convection flow of three different cookware materials composed of stainless steel, aluminum and enameled iron, when heating olive oil. A Computational Fluid Dynamic (CFD) software, called COMSOL Multiphysics©, has been used to analyze the heat transfer process for this study. In addition, a thermographic camera and a particle tracer were employed to compare the measurements of temperature, heat transfer and flow velocity, obtained from the CFD analysis. The results demonstrated that the enameled iron was the best choice of cookware material for induction stoves, as with the increment of oil temperature, this material had the biggest contrails and oil velocity convection flow in the center of the cookware.

Electrochemical behaviour of iron in molten enamel by means of cyclic, square wave and hydrodynamic voltammetry

The electrochemical behaviour of iron present in molten enamel is studied at a platinum disc electrode with cyclic and square wave voltammetry and at a platinum rotating disc electrode using chronoamperometry. Fe(III) is reduced in two steps to a Pt–Fe alloy, which disturbs the oxidation behaviour of Fe(II) considerably. Proof is shown for the formation of the alloy. Indications were found that the chemical equilibrium between Fe(III) and Fe(II) in homogeneous solution is attained slowly, which means that Fe(III) actual concentrations are measured instead of analytical concentrations. A consequence is that the diffusion coefficients determined with cyclic and/or square wave voltammetry and reported in the literature must be corrected. This was shown by using rotating disc chronoamperometry.

Elemental composition of teeth with and without odontoclastic resorption lesions in cats.

To determine elemental composition of teeth with and without odontoclastic resorption lesions (ORL) in cats. Normal teeth from 22 cadaver cats and ORLaffected teeth from 21 cats admitted to the veterinary hospital for dental treatment. An electron microprobe was used to analyze weight percentages of calcium, phosphorus, fluorine, sodium, magnesium, sulfur, potassium, and iron in enamel, dentin, and cementum. Calcium and phosphorus were the most abundant elements. Fluorine, sodium, and magnesium combined were < 5% and sulfur, potassium, and iron combined were < 0.1% of total elemental composition. In enamel of normal teeth, a significant sex-by-jaw location interaction was seen in mean (+/- SD) phosphorus content, which was higher in mandibular teeth of females (1764+/-0.41%) but lower in mandibular teeth of males (16.71+/-0.83%). Mean iron content in dentin of normal teeth was significantly lower in mandibular teeth than maxillary teeth (0.014+/-0.005% vs 0.023+/-0.019%). Mean enamel sodium content was significantly higher (0.77+/-0.046% vs 0.74+/-0.025) and mean enamel iron content was significantly lower (0.017+/-0.008% vs 0.021+/-0.005%) in ORLaffected teeth, compared with normal teeth. In cementum, mean fluorine content was significantly lower (2.98%+/-0.27 vs 2.99+/-0.20%) and mean magnesium content was significantly lower (0.54+/-0.13% vs 0.60+/-0.13%) in ORL affected teeth, compared with normal teeth. Results of our study establish baseline mineral content of enamel, dentin, and cementum for normal teeth in cats. Minimal differences in mineral content of enamel and cementum of normal and ORL-affected teeth were detected.

Absorption of iron by dentin: its role in discoloration.

This study investigated the effect of iron-containing mordants on the discoloration of human dentin. Dentin wafers with intact enamel borders were treated with one of several acid solutions containing iron. After exposure to aqueous sodium sulfide, color change was evaluated colorimetrically. X-ray photoelectron spectroscopy (XPS) and energy dispersive x-ray spectrometry (EDS) were used to probe surfaces for the presence of iron. Changes in surface morphology were evaluated by scanning electron microscopy (SEM). The results indicated that dentin treated by iron-containing solutions always discolored when the sodium-sulfide concentration exceeded 9.7 mM; variability in discoloration occurred below this level. XPS detected iron in enamel but not in dentin, while EDS detected iron in both enamel and dentin. Since XPS probes the upper atomic layers, these results indicate that acid-demineralized dentin absorbs iron; however, a water wash removes iron from the uppermost dentin surface, suggesting that the iron is physically absorbed. When exposed to sodium sulfide, at least some of the iron remaining in the bulk region is able to migrate to the surface to form iron-sulfide compounds. Based on SEM findings, discoloration is associated with the formation of a surface film on dentin.

The technology of casting enameled iron lids

The technology of casting enameled iron lids

Incorporation of iron in rat incisor enamel

ABSTRACT – The electron microprobe technique was used to study the accumulation of iron in rat incisor ameloblasts as well as the subsequent release of iron from the cells and deposition into the outer layer of the enamel. Starting about 3 mm from the developing end, a gradual accumulation of iron occurred in the ameloblasts. At a stage where the iron content of the cells had reached a maximal level, and the calcium content of the adjacent hard tissue had reached the level of mature enamel, the initial incorporation of iron in the enamel was seen. In the iron incorporation zone the iron content of the enamel increased from less than 0.1 % to about 9 % and the iron content of the ameloblasts was gradually reduced. Concomitant with the increase of iron in the enamel, a decrease of the calcium content was observed in the same region, indicating a withdrawal of calcium from the enamel. Since the incorporation of iron occurs at a stage where the enamel is highly mineralized, the processes involved can hardly be explained as an interaction with the organic matrix. The key to the understanding of these processes should therefore be sought in the adjacent cell layer.

Quantitative High‐Temperature Oxidation of Porcelain Enameled Iron

A continuous gain‐in‐weight method was used to measure quantitatively the oxidation taking place at elevated temperatures for long periods of time on enameled and unenameled iron. The oxidation was studied as a function of time and temperature on both bare and enameled iron. Specimens were subjected to variations in (1) enamel thickness, (2) thickness of electroplated‐nickel deposit, and (3) metal surface preparation of the iron. The rate of oxidation of enameled iron was lower than that of bare specimens at all temperatures. This effect was most significant at lower temperatures; it decreased in extent as the test temperature was increased to 1850°F. An increase in enamel thickness was very effective in reducing the rate of oxidation. To a lesser extent, an increase in nickel‐plate thickness on both enameled and unenameled specimens, and the use of sandblasting instead of mechanical abrasion and chemical cleaning as a method of metal preparation before enameling, also reduced the rate of oxidation. After the initial oxidation had proceeded at a linear rate, the oxidation rate of enameled and unenameled specimens followed a parabolic relation.

Effect of Firing Schedules on Stress‐Temperature Relations in Enamel‐Metal Systems

The effect of box and continuous enameling furnace firing schedules on the thermal deflection of enameled iron strips was studied. Effective coefficient of thermal expansion values were calculated from coefficient of thermal deflection data. Results indicate that the effective thermal expansion values for annealed and unannealed enameled iron agree with the expansion data obtained by an interferometer study of the same enamels. Variation in the cooling rate of the enameling furnaces studied is sufficient to produce a marked change in the development of thermal stress in the enameled iron. Residual compressive stresses in the enamel are increased by rapid cooling from firing temperatures. Tensile stress developed in the enamel during reheating is reduced by previous annealing.

A Study of Hairlining

A test for the hairlining tendencies of enamels is presented. A curved 4‐ by 8‐in. piece of 18‐gauge enameling iron is used as a test piece in which a simulated service condition of strain is produced by a 2‐ by 2‐in. piece of 16‐gauge enameling iron placed on the top center of the test piece. Before enamel application the specimen is curved lengthwise in a mold of 1 1/2‐ft. radius of curvature with a resulting permanent distortion of approximately 1/8 in.; the strain condition is obtained by an unattached straining piece. These two conditions enable good reproducibility of the direction and magnitude of the distortion due to uneven heating during firing, and the resulting pattern of hairlines varies only as influenced by enameling variables. The stepwise process of hairline formation is described with the aid of photographs and photomicrographs of enamel surfaces and cross sections. The effects of ground‐coat and cover‐coat variables and the significance of proper firing schedules are presented and discussed.

A Radioisotope Study of Cobalt in Porcelain Enamel

A typical porcelain enamel ground coat containing a small amount of radioactive cobalt as oxide was prepared, applied to sandblasted enameling iron blanks, and fired under conditions selected to give underfired, normally fired, and overfired coatings, respectively. Examination of these specimens revealed that a cobalt‐bearing metallic deposit had been formed at the enamel‐metal interface during firing, and that the enamel layer was depleted in cobalt oxide near the interface. The amounts of such deposit and depletion were found to vary directly with the severity of the firing treatment. The amount of metallic deposit was extremely small, on the order of 0.01 μ thick if computed as a continuous layer of metallic cobalt in the case of the normally fired specimens.

X‐Ray Study of the Reactions at the Steel Surface When Titania Enamel Is Applied Directly

A detailed X‐ray diffraction study has been made of the reactions which occur at the enamel‐steel interface during the firing of a titania enamel directly on steel. The following crystalline compounds have been found near the interface under various conditions: (1) Fe3O4, (2) FeO, (3) FeTiO3, (4) anatase, (5) rutile, (6) nickel‐iron alloy, and (7) an unidentified compound designated “unknown X.” The Fe3O4 and FeO make up the initial oxide layer which forms on the steel before the enamel fuses. The FeTiO3 is formed by reaction between dissolving FeO and dissolved TiO2 in the enamel. Anatase is the primary opacifying crystal which precipitates because of supersaturation of the frit, but it is drawn back into solution as FeTiO3 precipitates. Rutile is a secondary opacifier which forms relatively slowly and apparently causes the re‐solution of the FeTiO3. The nickel‐iron alloy appears only as a trace and probably comes from reaction between FeO and a small amount of nickel oxide formed on the nickel‐flashed samples. The most important observable effect of nickel pickling is its drastic reduction of the amount of oxide initially formed. Increasing the firing temperature increases the rates of all the reactions, but most particularly the precipitation of rutile and the disappearance of FeTiO3. The adherence development of this enamel on Ti‐Namel steel is dependent to a great extent on the weight of nickel deposit and the firing temperature and time. The theory that adherence depends on the presence of an oxidizing agent in the enamel adjacent to the steel has been applied to this system, and a correlation has been obtained on the assumption that dissolved TiO2 is the adherence‐promoting oxidizing agent. The titania enamel does not develop adherence on a regular enameling iron under conditions where good adherence is developed on Ti‐Namel steel, although the reactions in the enamel are essentially the same. This may result from observed differences in crystal orientation or texture, behavior of the nickel deposit, or effects of hydrogen.

X‐ray Diffraction Study of the Oxidation Characteristics of Nickel‐Pickled Sheet Iron as Related to Enamel Adherence

A systematic X‐ray diffraction study was made of the effect of nickel pickling on (1) the oxidation of bare enameling iron and (2) the reactions taking place under ground‐coat enamels. Nickel pickling reduces the amount of oxide formed during the heat‐up part of the firing cycle and favors the formation of Fe3O4, rather than of FeO. Since less oxide is formed on nickel pickled steel, the enamel can completely dissolve the initial oxide layer in a shorter time or at a lower temperature. With a typical high‐temperature ground coat, the time and temperature conditions required for adherence development can be correlated with the conditions required for removal of the oxide layer. With a low‐temperature ground coat, however, complete solution of the initial oxide layer does not insure adherence unless nickel pickling is used. Possible explanations for this latter effect exerted by nickel pickling are discussed. Metallic precipitates have been found in normal ground coats regardless of whether adherence is good or poor.

Some Ceramic Manufacturing Developments of the Western Electric Company

A general picture is given of the development work involved in the introduction of manufacturing processes for vitreous enameled resistances, vitreous enameled iron and copper base number plates, pressed glass lenses, extruded and pressed porcelain parts, and close tolerance ceramic insulators for use in telephone apparatus. The reasons for undertaking the manufacture of these products, some of the major problems encountered in developing suitable processes, and the work done in overcoming these difficulties including several major contributions to commercial methods of manufacturing similar parts are described.

Observations of the action of sulfide waters and muds of the Chistopol region

Fikovskaya water. For a long time the local population has been using Fikovskaya water with success for the treatment of various rheumatic diseases. The fame of Fik's sources spread to all neighboring regions. The number of patients who come here is quite significant. The local population treats the sick with water in tin baths, heating the water in enameled cast iron. In the warm season, this village turns into a primitive resort, where patients undergo treatment without medical supervision.

A FURTHER PROGRESS REPORT ON THE STUDY OF GASES IN ENAMELING IRON*

ABSTRACTSpectrographic 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.

VITREOUS ENAMEL AND ITS DEFECTS1

ABSTRACTCauses for various defects in enameled cast iron ware are traced in the enamel Photographs show the iron defects.

Combined Instrument and Sponge Stand and Sterilizing Apparatus.

The accompanying photographs show two satisfactory additions to the operating-room. The first is a combined instrument and sponge-tray stand. It consists of an enameled-iron leaf or table on one side for the instruments, and on the opposite of two rings which support two porcelain basins of large size. One of these is used for small sponges, the other for large ones. At the bottom of the stand is another ring supporting a deep basin, which is also of enameled iron. To the surgeon, who operates with little or no assistance, this table will be of especial advantage; the basin at the bottom is a receptacle for soiled sponges. In my work I handle all instruments, sponges, in fact everything, using no assistant. I place my instruments either in trays on the solid leaf or on a sterilized towel spread over the leaf—the table standing at my right —with the small