Sintering Mixture

The early history of the cement is obscure. Dreschfeld (1907) and Sanderson (1908) attributed its invention to Fletcher. Fletcher (1878,1879) certainly described cements formed from concentrated orthophosphoric acid solutions and sintered mixtures of oxides which included SiOj, AljOj, CaO and ZnO. One was reported by Fletcher (1879) as being slightly translucent. These cements were not successful in clinical use. 

Thermistor basedflow-through calorimetric sensors. Enzyme thermistors make the most widely developed type of heat measurement-based sensors. The thermistors are normally used as temperature transducers in these devices. Thermistors are resistors with a very high negative temperature coefficient of resistance. They are ceramic semiconductors made by sintering mixtures of metal (manganese, nickel, cobalt, copper, iron) oxides. Like the two previous groups, thermistor sensors do not comply strictly with the definition of "sensor" as they do not consist of transducers surrounded by an immobilized enzyme rather, they use a thermistor at the end of a small... 

In the case of cast iron enamelling, premelted frit is often replaced by a sintered mixture of raw materials which is then ground with the necessary ingredients. The application and the other subsequent operations are similar to those used with steel sheet products. 

Derivation (1) Sintering mixtures of metal powder and boron at 2000C (2) reduction of mixture of the metal oxide and boric oxide with aluminum, silicon, or carbon (3) fused-salt electrolysis (4) vapor-phase deposition. 

The instrumentation for fabrication of the ET normally employs a thermistor as a temperature transducer. Thermistors are resistors with a very high negative temperature coefficient of resistance. These resistors are ceramic semiconductors, made by sintering mixtures of metal oxides from manganese, nickel, cobalt, copper, iron and uranium. They can be obtained from the manufacturers in many different configurations, sizes (down to 0.1-0.3 mm beads) and with varying resistance values The best empirical expression to date describing the resistance-temperature relationship is the Steinhart-Hart equation ... 

Samples of various stoichiometries were prepared by sintering mixtures of the hydrides and graphite in the appropriate ratios under vacuum ca. 10 bar) at 1673 K. Determination of carbon (combustion), oxygen and nitrogen (reducing fusion under He), as well as phase analysis (X-ray diffraction and metallography) are mentioned, but no details were given. Elementary analysis indicated metallic impurities in amoimts smaller than 300 parts per million. 

The development of the dental silicate cement in its final, satisfactory form occurred slightly later than the development of the zinc phosphate, though it, too, traces its earliest history back to the later 1870s. The pioneering woik on this material was reported in 1878 and 1879 by Fletcher [15,16], and involved canents prepared from concentrated solutions of orthophosphoric acid and sintered mixtures of oxides, including silica and alumina, with inclusions of calcium oxide and zinc oxide. One of these cements showed slight translucency when set [16], but overall the cements were not a success clinically [7]. 

Yb2Fc3Si5 crystallizes with the ScjFejSij-type of structure [P4/mnc, a = 10.36(1) and c= 5.385(8)] Braun (1980) by means of X-ray powder diffraction. Arc melted samples were said to contain 20 vol% of impurity phases. No homogeneous sample could be obtained from sintered mixtures of Yb and FejSij at 900°C in an evacuated silica tube. For low temperature heat capacity data, see Vining and Shelton (1983) antiferromagnetic ordering was reported at T j = 1.70 K. 

In the case of the sintered mixture of dendritic copper and Cu/ZnO catalyst powder [35] forming the reactor walls, the final reactor design included vaporization, CAR of methanol and selective CO oxidation for CO reduction in the presence of hydrogen (Figure 25.6). For the vaporization and selective CO oxidation, the sintered metal was additionally coated with platinum. The outlet flow of the reactor consisted of 40% hydrogen, 20% CO2, 0.1% CO and residues of 1.2% methanol (dry basis, balance N2) at a steam to carbon ratio of 1. 

Figure 25.6 Cross-section, top and bottom views of a sintered mixture of dendritic copper and Cu/ZnO catalyst (35).

Crystalline Single-crystal membranes (e.g. LaFg), and pressed or sintered mixtures of Ag2S with AgX or MS (X = halide, M = Pb, Cu or Cd) to give electrodes sensitive to F, S, X or M ions respectively. 

Hafnium Silicate. A compound analogous to zircon, hence the suggested name hafnon. It can be synthesized from the oxides at 1550°C. Thermal expansion (150-1300°C), 3.6 x 10-6. Hafnium Titanate. Special refractory compositions have been made by sintering mixtures of Hf02 and Ti02 in various proportions. The m.p. of these... 

Nemst Body. A sintered mixture of thoria, zirconia and yttria together with small amounts of other rare-earth oxides. After it has been preheated to about 2000 C this body becomes... 

Semiconductor thermometers can be built in many shapes. Frequently they are very small beads, so that their heat capacity and thermal lag are small. They may also be made in form of large disks, so that they can average the temperature over a larger object. Typical materials which are used in thermistor thermometers are iron oxide, magnesium chromate, magnesium aluminate or sintered mixtures of nickel oxide, manganese oxide and cobalt oxide. 

E Mousa et al., Effect of Nut Coke-Sinter Mixture on the Blast Furnace... 

Composite agglomeration process (CAP) is an iimovative method for preparing blast furnace burden[2-5]. Its principle can be summed up as 1) firstly, fine grained resources obtained from varied process are pelletized, 2) pellets are mixed into traditional sintering mixture, 3) and then the mixture is fired in sintering machine. 

The search for effective electrocatalysts led to investigations of the corrosive resistance and of the reactivity for the O2 reduction of compounds of metals with other elements like boron, carbon, nitrogen, oxygen, etc. The cathode [78] of the Bacon cell represents the classical example. The porous cathodes were made by pressing and sintering mixtures of carbonyl nickel and ammonium bicarbonate. Subsequently, they were coated with a layer of lithiated nickel oxide. 

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