Moderate Temperature Range Research Articles

Concentrations of some ionic species in Central Long Island, New York precipitation in relation to meteorological variables

Three years of hourly sequential precipitation data from central Long Island, New York were analyzed to determine the concentrations of major anions and cations and their relationships to each other and to meteorological conditions. Findings with respect to sulfate, nitrogen in nitrate plus nitrite, nitrogen in ammonium, chloride and sodium ions and selected ratios are reported here. Concentrations of each of the first three species were highly correlated with concentrations of the others and with hydrogen ions. Little correlation was found between these species and either sodium or chloride ions but the latter two were highly correlated with each other. Concentrations of the first three species are highest in summer and lowest in winter. High concentrations were also found with cold front and squall line precipitation and with rain showers and thundershowers. Concentrations of these species are high with both low and high precipitation rates. Concentrations are highest with west and northwest winds due to the presence of major source regions in those directions. They are high with both low and high temperatures but lower in the moderate temperature range. Concentrations are high with low (3.0 to 3.9) and with high (6.0 to 6.9) pH but less at intermediate levels. Thus, concentrations of these species in precipitation are determined by complex chemical and meteorological interactions and relationships. Chloride and sodium were found to be largely of marine origin. Highest concentrations occur in the fall and with hurricanes, strong winds, and onshore wind directions. Concentrations decrease with increasing precipitation rate. At low concentrations, the chloride/sodium ratio is above the seawater ratio and excess chloride is present. At high concentrations the ratio is below the seawater ratio and a chloride deficit exists.

Accuracy of temperature measurements in determining the thermal conductivity of substances by stationary methods in the range of moderate temperatures

An empirical comparison is made of the accuracy of platinum-rhodium-platinum and Chromel-Alumel thermocouples in determining the thermal conductivity of substances.

Some regularities in the variation of heat-resistant nickel alloy fatigue resistance under the combined action of alternating and static loading

1. Static tensile loading, characteristic for the operation of gas turbine rotor blades, leads to a reduction in fatigue resistance and endurance of heat-resistant EI867 and VZhL12U nickel alloys. The magnitude and intensity of the reduction in fatigue resistance under the influence of static tensile load depends on the temperature range (above and below 0.6TM) at which the load is applied. 2. The nature of the limiting condition for heat-resistant alloys under asymmetric loading conditions is expressed in the form of an ultimate stress diagramσ a −σm, and is also defined by the temperature level. A linear relationship between values ofσ a andσm is appropriate for the moderate-temperature range (below 0.6TM). In the high-temperature range (above 0.6TM) ultimate stress diagrams satisfactorily approximate two straight lines, characterizing the different intensity of the reduction in alternating failure stress amplitude with increasing mean stress. 3. Two basic forms of failure, fatigue and quasistatic, are possible during tests on heat-resistant alloys in the high-temperature range with different ratios of alternating and static loading and a smooth loading schedule. The level of material ductility realized, determined as the ratio of accumulated unilateral plastic strain ɛ∑(t) during cyclic loading to long-term ductility ɛf(t), can serve as a criterion of the failure type.

Nature of X phase in alloys of the YuNDKT type

1. The nature of X phase (“overheating phase”) in alloys of the YuNDKT type was investigated by metallographic and x-ray analysis. 2. The X phase is high-temperature γ phase supercooled to room temperature. 3. The type of lattice and lattice constants of the phase were determined, which we call γII phase. The γII phase has a fcc lattice witha=3.61 A. 4. The experimental data from this work and from [1] do not support the contention [4] that a new phase differing in principle from γ phase in the moderate temperature range is formed in YuNDKT alloys in the temperature range adjoining the solidus.

The Effect of Low Versus Moderate Rearing Temperature on Broiler Performance

Rearing commercial broilers from 4 to 8 weeks of age in constant temperatures of 10° and 21.1° C. resulted in the same body weight gain at both 6 and 8 weeks of age. When a comparison is made between broilers reared under constant versus cyclic temperatures that were cycled in the moderate and low temperature range, more average body weight gain was obtained at 8 weeks of age for birds reared in the cyclic temperature regime. The amount of feed required to produce a unit of body weight was higher for the birds reared in the lower temperatures.

The Characteristic of Gold and Aquadag Contacts with Single Crystal Nickel Oxide Surfaces

The electrical characteristic of gold and Aquadag contact with single crystal nickel oxide surfaces is determined within a moderate temperature range around 273 K. The current-voltage characteristic of these contacts is linear, but the contact resistance is found not to be negligible when compared to the resistance of NiO samples of ordinary size.

A Nonlinear Spectral Model of Convection in a Fluid Unevenly Heated from Below

Abstract A two-dimensional form of the Boussinesq equations is integrated numerically for the case of a rectangular channel with a temperature gradient maintained along the bottom. The side walls are insulating, the top wall has a constant temperature, and the velocity obeys free boundary conditions on all four walls. The fields of stream function and temperature departure are represented by truncated double Fourier series, and integration of the initial-value problem for the spectral amplitudes results in steady states which agree qualitatively with those of previous experimental and theoretical investigations. Calculations are presented at two levels of truncation (wave numbers 2 and 3) for a wide range of Prandtl numbers and a moderate range of horizontal Rayleigh numbers and top temperatures. For sufficiently large gravitational stability, a single asymmetric convection cell develops. Its intensity and asymmetry increase markedly with increasing horizontal Rayleigh number, decrease with increasing top...

Effect of abrupt temperature shift on the growth of mesophilic and psychrophilic yeasts.

Exponentially growing cultures of mesophilic and psychrophilic yeasts were subjected to abrupt changes in temperature. Temperature shifts made within the range in which the temperature characteristic, mu, is relatively constant (moderate temperatures) immediately induced growth at the normal exponential rate for the new temperature. Prior incubation at temperatures defined as moderate enabled some yeasts to grow for a few generations at temperatures higher than their normal maximal temperature for growth. Shifts made to or from temperatures above or below those in the moderate temperature range resulted in growth rates that were intermediate between the normal steady-state rates for the initial and final temperatures. A period of transient growth rate at the new temperature outside the moderate temperature range seems to be required before normal steady-state growth rates can be attained after such temperature shifts. The psychrophiles gave transient growth rates only below 10 C, whereas the mesophiles gave transient rates below 20 C. However, the psychrophiles cannot be distinguished from the mesophiles on the basis of the temperature characteristic, mu, which was found to be about 12,000 cal/mole for both types.

Comment on "Viscosity of Air"

T points are to be made here with regard to Fiore's note. One is that there are no u ... experimental data . . . of Bromley-Wilke, and the other is that there exists a single equation to fit the viscosity of air from the lowest to the highest temperature to which data have so far been obtained. The Bromley-Wilke results are charts . . . for prediction of the effect of temperature at low pressures based on the refined kinetic theory of Chapman and Cowling as developed by Hircshfelder, Bird, and Spotz. The equation, proposed by Keyes, fits the Bromley-Wilke charts in the low to moderate temperature range, and fits available experimental data at the highest temperatures better than do the Bromley-Wilke values.

Measurements of the Viscosity of Krypton

The viscosity of krypton has been measured over the temperature range 297° to 666°K by the oscillating disk method using helium for calibration. The viscosities obtained were used to get the parameters for a Lennard-Jones 12–6 potential function and they were found to be ε/k=162°K and σ=3.734 Å. Calculation of the viscosity, thermal conductivity, self-diffusion coefficient, second virial coefficients in the moderate temperature range, and the heat of sublimation at 0°K from the L. J. 12–6 function gives very good agreement with experimental values. Calculated values for the second virial coefficient at low temperatures, the reduced thermal diffusion factor, and the lattice spacing at 0°K are in fair agreement with experiment.