LINEAR THERMAL EXPANSION OF “BETA-ALUMINA”*

An attempt to determine the linear thermal expansion coefficient of a sample of “beta-alumina” containing 4.47% K₂O and 1.03% Na₂O was unsuccessful because the expansion was irregular and not reproducible. On successive heatings, the expansion approached more and more closely that of alpha-alumina (corundum). This observation, together with the fact that the fused-silica parts of the expansion apparatus were badly etched during the measurements, apparently by alkali given off by the sample, gives further support to the view that “beta-alumina” is not an allotropic form of pure alumina but is an alkali aluminate.     

SUBJECT INDEX OF PLATING & FINISHING 1994

SUBJECT……………………………………AUTHOR（S）NUMBERPAGEIE16ctroplating互-INickelP！a！lugTheQualityofAdditivesAllowofnoNeglect·”……·”··’·’…··’··”……··’··”’·WangweicaiNickelElectroplatingofPerfOratedSteelTape…………·’…………”……··’··Dongshiyuan1-2ChromiumP！邑！lugManuf8ctureandUtilizationofAnodeinChromiumPlating…………………………LIHanElectroplatingHardChomiumCoatingwithMulti比notion…··’·’·’“”’””””“…·’·”……·”……     

SUBJECT INDEX OF PLATING & FINISHING 1995

SUBJECT…………………………………AUThOR侣）NUMBERPAGEIElectroplatingl-ICopperplatingAdditivesforPCBAcidicBrishtCopperPlating··’··”’……·’·’··’·‘…·’……·’DengWenetal39l-2NickelPlatingTheDevelopmentofProtectionMaterialforNickelCoatingonSteelSubstrate……………………………………………………………ZhansBaogenetal13互-3ChromlumP！aling0e81回na＊dApp！1＊UIOnO门一OforChroffi山mPI8tin区OnInnerwallofHoles…………………………………………………………XlanDongsh…     

METHOD OF CORRELATING CHEMICAL COMPOSITION RELATIVE AMOUNTS OF GLASSY BOND AND PROPERTÍES OF CERAMIC BODIES*

A method is given for correlating the chemical composition, relative amounts of glassy bond, and properties of fired ceramic bodies. The procedure consists of (1) plotting the compositions expressed in simplified terms on a reference diagram and (2) plotting data on the physical properties vertically from the plane of the reference diagram. Because the reference diagram contains the appropriate equilibrium diagram, the quantities of liquid and crystalline phases calculated for preparations of pure raw materials heated to equilibrium at a given temperature are useful (1) in estimating the relative quantities of glassy bond in fired bodies and (2) in differentiating fired bodies with respect to phase constituents. Data on fired whiteware are used to illustrate the relation of composition to the following properties: porosity, shrinkage, dielectric strength, and specific gravity.     

FUNDAMENTAL STUDY OF CLAY: VI,FLOW PROPERTIES OF KAOLINITE-WATER SUSPÉNSIONS*

The flow properties of six monodisperse kaolinite fractions were studied over a large range of concentration. From these results, it has been possible to set up an equation relating viscosity to concentration which holds over a very wide range. Equations relating concentration to thixotropy and to the yield point which have general application could also be established. The viscosity of a suspension is obtained from the sum of three quantities, namely, those contributed by (1) the liquid, (2) the individual particle, and (3) the collisions of the particles. Thixotropy is found to be due to the sum of two quantities, namely, the contribution of (1) the individual particle and (2) the interference of the particles. The yield point in these fractions was found to be proportional to the cube of the concentration. With these relations, it is possible to calculate the viscosity of a casting slip for any change in specific gravity.     

THE “MOISTURE EXPANSION” OF GLASSES1

Changes in the overall length of bars, about 4 by 3/4 by 1/8 inches in dimensions, made of plate glass, Pyrex glass, and various glasses such as constitute bonding agents in vitrified grinding wheels, were studied by means of a Zeiss optimeter that could be read to hundred thousandths of an inch. The bars were measured, then heated for one hour in (a) saturated steam at 150 lb. per sq. in., or (b) air oven at 184°C, and then allowed to cool to room temperature and remeasured. No increases in length of any of the bars were found within the experimental accuracy of the results (about 0.0015%).     

INFLUENCE OF VARIABLE AMOUNTS OF NEW YORK TALC,FLINT, AND CALCINED CLAY ON SERVICEABILITY OF GLAZÉD COOKING-WARE BODIES*

The effect of composition on the ability of glazed dishes to withstand thermal-shock treatments ordinarily received in cooking was studied. Bodies which gave best results contained approximately 10% of New York talc and also a small amount of calcined clay substituted for potters' flint. Bodies which had sufficiently high thermal expansion to throw the glaze into moderate or strong compression gave the best results. A terra sigillata finish applied to talc-free bodies was found to withstand autoclave treatment without crazing, and ware so made stood up very well in service tests.     

DRYING CHARACTERISTICS OF OSMOTICALLY PRETREATED CRANBERRIES—ENERGY AND QUALITY ASPECTS*

ABSTRACT

This study reports on finish drying of osmotically pretreated (dehydrated and sugar-infused) cranberries. The halved fresh berries pretreated in a standard osmotic solution (67.5 Brix at 50°C for 5 h) were then freeze-dried, vacuum-dried and air-dried in various dryers (cabinet-air-through, fluid bed, pulsed fluid bed, and vibrated fluid bed dryers) in order to identify the best drying technology. Energy consumption and product quality were chosen as the comparison criteria. The best product quality, quantified by the anthocyanins content, rehydration ratio, color and taste, was noted for freeze-dried berries. As all other drying methods gave similar, albeit slightly lower quality products than freeze-drying, the selection of a drying method could be based on the unit heat consumption. The vibrated fluid bed and the pulsed fluid bed should be favored because of the highest energy efficiency. Even though sugar infused into cranberries during osmotic pretreatment reduces drying rates during the second drying period as compared to untreated berries, osmotic dehydration reduces the total energy consumption on top of the preferential sensory characteristics of the final product.