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BEFORE EARNING a doctorate in music composition and becoming a university music professor, I spent many years playing keyboards and singing in CCM and praise and worship bands, and before [...]

Presents the short story "The Fifth Son of Roidah," by Marilyn R. Mumford.

Discusses judicial activism in the United States. Definition of judicial activism and judicial constraint; Power of judicial review of the American Supreme Court; Comparison of the Australian and American Constitution; Judicial activism in Canada; Decision based on a judge's preferred ideological or philosophical view.

Background: Calcipotriol is an effective treatment of chronic plaque psoriasis. We have previously demonstrated that it has a small effect on systemic calcium homeostasis even at recommended doses. Objective: We attempted to determine the mechanism of the effect of calcipotriol on sytemic calcium homeostasis so we could assess the possible consequences of long-term use. Methods: Sixteen patients with extensive chronic plaque psoriasis were hospitalized and treated with high-dose topical calcipotriol. Up to 360 gm of calcipotriol (50 @mg/gm) ointment was applied per week for 2 weeks under controlled conditions. Results: There was a dose-dependent rise in intestinal absorption of calcium. No effect on bone turnover was demonstrated over this short period. Five patients became hypercalcemic, and there was a dose-dependent rise in serum total adjusted calcium, serum ionized calcium, serum phosphate, urine calcium, and urine phosphate. There was a dose-dependent fall in serum parathyroid hormone and serum 1,25 dihydroxyvitamin D"3. Conclusion: Calcipotriol exerts its effects on systemic calcium homeostasis by increasing intestinal absorption of calcium and probably phosphate. This results in suppression of parathyroid hormone and 1,25 dihydroxyvitamin D"3. (J Am Acad Dermatol 1997;37:929-34.)

Seven ββ-dialkyl-α-aminopropionic acids, including five new compounds, have been synthesised as potential antiviral and antibacterial agents. None showed any significant activity against the Newcastle Disease virus in vitro.Several methods of preparation of the compounds have been investigated, and theories are advanced to explain the failure of some of these methods.

Seven new dialkylaminobutyric acids have been synthesised as potential antiviral and antibacterial agents. None showed any significant activity against the Newcastle disease virus in vitro.

This paper covers the first comprehensive study of the distribution of heat absorption in a natural-gas-fired, water-cooled, steam-boiler furnace. The use of a fuel free of incombustible residue revealed factors in furnace performance because ash was not present to mask the influence of such factors. The tube-surface temperatures on the furnace walls were essentially constant at any given rating and excess air, and were completely reproducible. After a lapse of more than a week a check test was made, and it was found that the indicated tube-surface temperatures were within a degree or two of their previous values. The obvious conclusion is that the shape of the “flame” envelope (invisible with natural gas) was independent of load, at least with fixed burner position and at fixed mixing-vane angles. There is no reason to suppose that the flame envelope and gas path in a furnace fired with pulverized coal would not also be the same at the same rating and excess air and with fixed positions of burners and mixing devices. This factor has not been apparent on previous tests because of the masking effect of variable ash deposits on the furnace tube surfaces. The test boiler, in normal service, was used at high load factor and high capacity. The mixing vanes and flows in the burners had been adjusted properly for this load condition after extended experience. Readjustment for each test load would have been time-consuming so vane adjustment was not attempted. When isotherms were drawn on plots of the furnace walls it was strikingly apparent that the pattern was similar at all loads with eight burners and with four burners. The gradient, or space between isotherms, varied with rating but the pattern was constant. This constancy of pattern indicated that as long as burners and mixing devices were not readjusted, the hot gases would impinge on the walls at the same spots at all ratings and, therefore, that the path of gases through a furnace is determined by the burner position and the geometry of the furnace and not significantly by rating or excess air. This factor was not apparent from the results of the previous pulverized-coal-fired tests because of the masking action of ash deposits on the surface of the furnace tubes. The usual flame, as observed in coal and oil-fired furnaces, was completely invisible in this natural-gas-fired furnace. Computations of radiant transfer indicate that about 80 per cent of the heat absorbed by the furnace was transferred by radiation. Estimates for luminous flames indicated that from 95 to 100 per cent of the heat absorbed in the furnace is transferred by radiation. In the first attempts to measure the furnace gas temperature at the burner level several impressive occurrences indicated that we were dealing with much higher temperatures than were expected. The porcelain shields, used to reduce radiation loss, shattered upon reaching the hot gases. The platinum and even the platinum-rhodium wires of the thermocouple melted. The analysis of the data indicated, by extrapolation, that temperatures of 3400 F were common within 10 ft of the burner. Such temperatures indicated effective mixing of fuel and air and very rapid combustion. Conservative estimates of heat release indicated values of 160,000 Btu per cu ft of space utilized for the completion of combustion. When the velocities of gas and air were lowered, for testing at lower loads, temperature measurements indicated that the mixing action was not as effective because the burner vanes were not readjusted to compensate for the reduced velocities. At partial loads studies of the gas temperature indicated that the impingement of the hot gases on the rear or target wall produced sufficient mixing to complete combustion at the burner level. No unburned products were found in the gas samples taken above the burner level at any load. It can be concluded, therefore, that with sufficient hot-air pressure and with a well-designed mixing burner, natural gas can be burned rapidly and completely at high heat-release rates. The temperatures of the gases leaving the furnace at constant steamload decreased with increase in excess air but the heat content of the mixture increased. The patterns of the isotherms of gas temperature at the furnace outlet vary markedly with the load. The addition of a widely spaced screen of tubes in front of the rear wall reduced the gas temperatures leaving the furnace from 50 to 100 F but also changed the pattern of isotherms so that the pattern was essentially the same at all loads. Probably the furnace-wall screen not only absorbed additional heat but also aided in the mixing action of the gases impinging on the wall and thus made the isotherms more uniform.

This paper is a report on studies of heat transfer and pressure drops in steam-generating tubes at pressures from 500 to 3300 psi and under exposure to furnace heat in large steam-generating units. Most of the test surfaces were in the form of flat spirally coiled tubes, but for comparison one straight tube 50 ft long was tested. Specific problems investigated include the influence of variations of the steam-water ratio and of variations in tube dimensions (scale factor) on tube-metal temperatures and on pressure drops. Some data relate to tubes operating under conditions approaching those often associated with operating failures. The test conditions were extended in several instances to include water below the saturation temperature. Some of the possible engineering analyses of the data have been made. Such an analysis of the relation of metal temperature to heat absorption and internal fluid conditions led to the proposal of a function ϕ which seems to offer some possibilities of development as a function correlating the factors influencing an abnormal rise in metal temperature. Similarly an analysis of the pressure drop has led to the proposal of a modification of the usual pressure-drop correlation to include the thermodynamic effect of transverse-momentum changes during evaporation. Supplementary investigations reported upon include pressure drop of water at saturation temperature for the pressure range 250 to 2500 psi, through flow-distributing equipment designed for forced-circulation boilers, and heat-transfer coefficients for the specific auxiliary equipment used.

The determination of heat-transfer rates by differential measurements of static pressure and by inlet velocity resulted in lower values and less consistent values than the rates determined by measurement of the surface temperature of the tube. The difference between the two methods can be attributed to a difference in the velocity of steam and water within the tube generally resulting in indications of higher density, as measured at the cold side of the tube, then as computed from the hot-surface temperature measurement and the water velocity entering the tube. Because the effect of rate of heat transfer, total heat absorption, relative rates of absorption along the length of the tube, and velocity of water entering the tube could not be easily segregated the relative velocities of steam and water could not be correlated with the other factors, and further field work on density, as determined differentially from static pressures, is not recommended. Laboratory work in which separate control of the variables is more practical may provide valuable data on bubble slip and circulation factors.

In this part of the symposium the three preceding sections of the report are compared, and satisfactory coordination is accomplished for the first two sections. The tube-surface temperature measurements show furnace heat absorptions which can be co-ordinated with the absorptions indicated by the surveys of the gas conditions at the furnace outlet by applying a correction to the gas-temperature measurement, or by varying the tube-to-water film conductance. A method of evaluating furnace cleanliness is developed and applied. A suggested basis of comparing furnaces is discussed.

This paper deals with the installation, operation, and maintenance of cloth filters for handling vented air from pulverized-coal mills. The experiences of the authors in solving problems in connection with the cloth-bag filter system, as used at the Kips Bay Station of the New York Steam Corporation, are the basis on which the subject is developed. Complete performance tests on a 40-ton-mill installation are cited.

In this paper the author gives particulars of studies made in an attempt to reduce or eliminate the moisture in steam from boilers operated at the high evaporative rate of 25 lb. per sq. ft. of boiler and furnace surface, using 90 per cent make-up and full chemical treatment in the boiler for scale elimination. From these studies he concludes that: 1 The concentration of the hydroxyl radical is a factor in the production of wet steam which acts independently of the rate of evaporation, or of the concentration of other solid or dissolved chemical substances, and which has a critical value varying with the boiler design. 2 The production of dry steam at high rates of evaporation is partly a problem of reentrainment of the separated water due to inadequate drainage. 3 If it is assumed that the physical condition of the water-steam mixture on any boiler heating surface varies only with the rate at which heat is being absorbed by that surface, then the problem of moisture elimination is reduced to one of steam-path design applicable to boilers in general.

Presents letters to the editor referencing articles and topics discussed in previous issues. "An American Darkness," which described the bombing of the federal building in Oklahoma City as a political act; "Sleazy Genius," which claimed that U.S. Commerce Secretary Ron Brown succumbed to a corrupt legal and lobbying culture; "Altar Ego," which recognizes the significance of the use of the song "You'll Never Walk Alone" in the motion picture "Priest."