The normal and pathological movement of water in tissues and its relation to the colligative properties of solutions and to inflammation.
A series of studies, each suggested by those that preceded, were first concerned with the movement of water in parenchymatous cells of liver, kidney, submaxillary glands, and other glandular organs. Evidenee was soon obtained showing that these cells were isotonic as determined by the osmotic pressure they maintained, not with physiological salt solution (0.15 M), as at that time popularly assumed, but with sodium chloride in approximately twice this concentration. Cells of the liver or of the kidney acted as osmometers and measured the osmotic pressure which they maintained. When various eleetrolytes were tested, it was found that their osmotic pressures varied with the valence of the basic ions of the salts that were used, being, for example; I for monovalent sodium salts, 2 for calcium salt, 3 for lanthanum salts. Solutions of the salts of eleetrolytes manifest properties so bound together that they are designated colligative. These properties include osmotic pressure, depression of the freezing point, vapor tension, and boiling point of solutions. It is well established that any one of them provides data from which the others can be dedueed by appropriate calculation.1 The changes which oceurred in liver or in kidney were found to be in aecord with tables which record changes in the freezing point of graded solutions of salts of electrolytes, on the one hand, or of boiling points on the other. Visible necrosis of the skin of laboratory animals was produeed by injeetion into the dermis, and the molar strength of solutions of various electrolytes needed to cause it was determined. This varied with the valence of the basic ions of the salts that were tested and followed a sequence which was the same as that of the isotonicity of liver or of kidney cortex immersed in corresponding solutions. The molar concentration of amino acids that produced necrosis followed the same order as osmotic pressure of liver in the same solutions. The relation of necrosis to the colligative properties of electrolytes suggested a study of the relation of inflammatory reactions to the moleeular constitution of agents that cause them. Injection of injurious substances into the large serous cavities of the body, peritoneal and pleural, offered a method by which exudation of fluid, leucocytes, and plasma protein could be measured with considerable accuracy. The numerical results thus obtained give an adequate measure of the inflammatory reactions. The relations cited emphasize the dependence of normal and pathological changes upon the colligative properties of electrolytes and of organic compounds which direet the movement of water and of the compounds it may contain. With these relations in mind, it has seemed desirable to review the sequence of studies which were undertaken to measure the movement of water in cells and interstitial tissue under normal and under pathological conditions.
AN OSMOTIC SYSTEM WITHIN THE CYTOPLASM OF CELLS
The cytoplasm of cells of the liver and of the kidney is in large part occupied by bodies which respond to the water content of these cells and are modified by dissolved substances in the surrounding fluid or by physical change such as freezing. These bodies, in part mitochondria but designated more broadly cytochondria, constitute an osmotic system within the cytoplasm of cells. When the specific gravity of liver or kidney tissue is used as an index of changes in the water content of tissue, swelling of cytochondria in general follows the intake of water but this relation may be modified by a variety of conditions. When liver that has been frozen and thawed is immersed in water, cytochondria become swollen though the containing cells diminish in size. Solutions of sodium and of potassium chloride isotonic with blood plasma cause delayed swelling of cells and cytochondria, greater with the potassium salt; solutions of calcium chloride of equal molar concentration cause immediate swelling of cells and cytochondria. The basophile material of the cytoplasm (ribonucleic acid and related substances) and the material that gives to mitochondria their characteristic stain are removed by immersion in water but their disappearance is retarded by isotonic solutions of sodium or of potassium chloride and further delayed by hypertonic solutions. When the intensity of staining reactions is diminished by the partial loss of basophile substance or of the distinctive mitochondrial material, these are found at the surfaces of the cytoplasmic bodies, held perhaps by adsorption. When water, isotonic solutions of sodium chloride, or Ringer's solution comes into contact with immersed liver, they remove basophile and mitochondrial material from a superficial zone and substances with similar staining reactions appear in the cytoplasm of cells at a deeper level. Osmotic changes in the cytoplasmic bodies may be reversible. When liver tissue which has been for a short time immersed in water is transferred to a solution that is approximately isotonic in relation to blood plasma, swollen cytochondria return in part or completely to their former size; but with continued immersion in water, this reversibility becomes increasingly less complete.
Effect of spray nozzle design on liquid-solid contact in fluidized beds
Abstract In industrial fluid cokers the feedstock, consisting of heavy bituminous hydrocarbons, is atomized with steam and injected into a hot fluidized bed of coke. Good and uniform contact of the liquid droplets with the solid particles is required to provide heat for the cracking reactions while minimizing mass transfer effects. Experiments in a pilot plant coker have suggested that the initial particle/liquid mixing, in the spray jet, is rather poor. Experiments in a X-ray scanner showed that liquid droplets and entrained particles accumulate just below the tip of the jet plume to form agglomerates. An experimental technique was used to quantitatively determine the quality of mixing with a variety of nozzle configurations including several novel designs. By improving spray stability, redistributing liquid droplets to the solids-rich region of the jet and increasing the surface area of the gas–liquid jet-fluidized bed interface, liquid/solid contact is improved.