scholarly journals Computing the Absolute Temperature and Entropy from the Integral of Heat: -- The Development of Characteristic Coordinates for Thermodynamics --

2006 ◽  
Vol 115 (4) ◽  
pp. 673-682
Author(s):  
T. Sugai
Keyword(s):  
Absolute Temperature ◽  
The Absolute ◽  
Characteristic Coordinates

The specific heats of three paramagnetic salts at very low temperatures

1956 ◽  
Vol 237 (1210) ◽  
pp. 395-403 ◽  
Keyword(s):  
Specific Heat ◽  
Absolute Temperature ◽  
Magnesium Nitrate ◽  
Paramagnetic Resonance ◽  
Specific Heats ◽  
Ammonium Alum ◽  
Relaxation Measurements ◽  
Ferric Ammonium ◽  
The Absolute ◽  
Measured Specific Heat

The specific heats of three paramagnetic salts, neodymium magnesium nitrate, manganous ammonium sulphate and ferric ammonium alum, have been measured at temperatures below 1°K using the method of γ -ray heating. The temperature measurements were made in the first instance in terms of the magnetic susceptibilities of the salts, the relation of the susceptibility to the absolute temperature having been determined for each salt in earlier experiments. The γ -ray heatings gave the specific heat in arbitrary units. The absolute values of the specific heats were found by extrapolating the results of paramagnetic relaxation measurements at higher temperatures. The measured specific heat of neodymium magnesium nitrate is compared with the value calculated from paramagnetic resonance data, and good agreement is found.

A Fluidity-Temperature Relationship for Liquids

1973 ◽  
Vol 95 (2) ◽  
pp. 236-241
Author(s):  
T. F. Ford ◽  
C. R. Singleterry
Keyword(s):  
Interpolation Formula ◽  
Absolute Temperature ◽  
Temperature Relationship ◽  
Organic Liquids ◽  
Low Viscosity ◽  
Linear Relationships ◽  
Temperature Ranges ◽  
The Absolute ◽  
The Relationship

Many relationships between viscosity or its reciprocal, fluidity, and temperature have been proposed for liquids. None except the empirically modified ASTM chart have proven satisfactory over extended temperature ranges. We here note that by plotting the kinematic fluidity (φkin) against the square of the absolute temperature (deg K2) we obtain linear relationships for a wide variety of organic liquids at kinematic viscosities less than about 1.67 centistokes (or fluidities above about 0.60 reciprocal centistokes). The generality of the relationship appears to justify the use of the equation, φkin=a+bT2, as an interpolation formula for organic liquids in the low viscosity region.

scholarly journals Absolute temperature directly from plank’s profile: A simulation

2021 ◽  
Vol 33 (2) ◽  
pp. 9-19
Author(s):  
V. VIJAYAKUMAR ◽  
Keyword(s):  
Thermal Radiation ◽  
Response Function ◽  
Wave Length ◽  
Absolute Temperature ◽  
Scale Factor ◽  
Material Surface ◽  
Measured Spectrum ◽  
The Absolute

The measured thermal radiation from a material surface will, in general, have a wave length (\lambda) dependent scale-factor to the Planck profile (PT) from the contributions of the emissivity (Є\lambda) of the surface, the response function (A\lambda) of the measurement setup, and the emission via non-Plank processes. For obtaining the absolute temperature from such a profile, a procedure that take care of these dependencies and which relay on a temperature grid searchis proposed. In the procedure, the deviation between the Plank profiles at various temperatures and the measured spectrum that is made equal to it at a selected wavelength, by scaling, is used. The response function (A\lambda) is eliminated at the measurement stage and the polynomial dependence of the remnant scale factor mostly dominated by Є\lambda) i s extracted from the measured spectrum by identifying its optimal \lambda dependence. It is shown that when such a computation is carried out over a temperature grid, the absolute temperature can be identified from the minimum of the above deviation. Here, search for T and Є\lambda) d elinked, unlike in the leastsquare approaches that are normally employed. Code that implements the procedure is tested with simulated Planck profile to which different viable values of Є\lambda) a nd noise is incorporated. It shown that if the \lambda dependence of scale-factor is not too high, the absolute temperature can be recovered. A large \lambda dependent scale-factor and the consequent possible error in the temperature obtained can also be identified.

scholarly journals The basic characteristics of the Belgrade’s heat island

2003 ◽  
Vol 83 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Goran Andjelkovic
Keyword(s):  
Air Temperature ◽  
Space Structure ◽  
Absolute Temperature ◽  
Heat Island ◽  
Temperature Minimum ◽  
City Center ◽  
Climatic Period ◽  
Average Annual Temperature ◽  
The Absolute ◽  
The City

The urban heat island, as a phenomenon due to the higher air temperature in the cities as compared to their immediate surroundings, represents the most important consequence of the urbanization influence on the topoclimate. As compared to the smaller cities in its surroundings, Belgrade's average annual temperature is from 0,4 to 1,0 ?C higher (period 1961-1990). A very liable index of the Belgrade's heat island is the air temperature measured at the airport in Surcin. In the period from 1971-1990. average annual air temperature at the airport was 11,2 ?C, and in the city center it was 0,7 ?C higher. Belgrade has a higher absolute minimal temperature than its surroundings during every month. In the last climatic period the absolute temperature minimum in Belgrade was even 5,4 ?C higher than the highest value measured within this parameter in its wider surroundings (Veliko Gradiste -26,4 ?C). In the above mentioned twenty years period the absolute air temperature minimum in Surcin was -26,0 ?C, and in the city center only -18,2 ?C. The number of the frosty days at the airport was 77,8, and in Belgrade 58,2. Although the heat island of Belgrade was formed together with formation of the city, it was more evident at the beginning of the 20th century (0,4 ?C). During the next five to six decades a faster intensity growth was recorded (up to 0,9 ?C). This coincides with the period of the population growth as well as with development of the city activities, industry above all. During one year the intensity of the Belgrade's heat island reached its maximum in winter. In January the city, as compared to Surcin, was warmer for about 1,0 ?C, and in September for only 0,1 ?C. The daily variations of the heat island are such that it reaches its highest intensity during the evening hours (at 9 p.m. 0,9 ?C). If the average values of the extreme daily temperatures are being examined, one can see a distinct difference: average city minimums are 1,5 ?C higher than the airport minimums, while the maximums are only 0,2 ?C higher. During winter, in concrete anticyclonic conditions, it can be 10 ?C warmer in the city than in the immediate surroundings. Together with the perennial growth of heat island intensity, its "space range" also expands. The space structure of the heat island is very distinct. Exceptions in the temperature values between certain points of measurements in the winter morning hours can go up to 6-8 ?C.

scholarly journals The CBR frequency spectrum below 1 GHz recent results and new observations

1992 ◽  
Vol 9 ◽  
pp. 297-298
Author(s):  
G. Sironi ◽  
G. Bonelli ◽  
M. Gervasi
Keyword(s):  
Frequency Spectrum ◽  
Absolute Temperature ◽  
History Of ◽  
The Absolute ◽  
The Universe

AbstractWe are carrying on measurements of the absolute temperature of the CBR at various frequencies near and below 1 GHz, looking for so far undetected deviations from a planckian spectrum. The amplitude and frequency of those distortions can give precious information about the history of the Universe.

The nuclear specific heat in paramagnetic cupric salts at temperatures below 1° K I. Thermodynamic measurements made from a study of the field-dependence of the adiabatic susceptibility

1950 ◽  
Vol 203 (1074) ◽  
pp. 375-391 ◽  
Keyword(s):  
Magnetic Susceptibility ◽  
Specific Heat ◽  
Field Dependence ◽  
Absolute Temperature ◽  
Potassium Sulphate ◽  
Specific Heats ◽  
Magnetic Cooling ◽  
Thermodynamic Measurements ◽  
Small Fields ◽  
The Absolute

Thermodynamic measurements have been made at temperatures below 1°K, obtained by the method of magnetic cooling, on copper potassium sulphate and on a diluted copper Tutton salt. A study has been made of the field- dependence (for small fields) of the adiabatic susceptibility of the cooled and thermally isolated salt, the measurements covering the range of temperature from 1°K down to 0.05°K for copper potassium sulphate, and to 0.025° K for the dilute salt. From these measurements the entropy and magnetic susceptibility are determined as functions of the absolute temperature. It is concluded that for both salts the susceptibility follows a Curie-Weiss law, the values of ∆ being 0.034 and 0.0048º K respectively; the specific heats are of the form ∆ / T 2 , the values found for A being 6.1x10 -4 R for copper potassium sulphate and 1.98x10 -4 R for the dilute salt.Deviations from this behaviour in a ferromagnetic direction are found for copper potassium sulphate below 0.07° K.

scholarly journals Absolute Calibration of Stellar Temperatures

1973 ◽  
Vol 54 ◽  
pp. 153-155
Author(s):  
H. Kienle ◽  
D. Labs
Keyword(s):  
Spectral Energy Distribution ◽  
Black Body ◽  
Absolute Temperature ◽  
Spectral Energy ◽  
Absolute Calibration ◽  
Standard Star ◽  
The Absolute ◽  
Stellar Temperatures ◽  
Image Position ◽  
Radiation Laboratory

The scale of effective temperatures Teff is based on observed absolute radiation temperatures Tr, which are defined by Planck's radiation law where TAu designs the absolute temperature of the gold point. A relative scale of radiation temperatures can be derived from spectrophotometric comparisons with a standard star. The absolute calibration of the standard star (α Lyr or Sun) demands a careful comparison with a standard radiation source of well known spectral energy distribution (Black Body or Synchrotron). With ground-based observations atmospheric extinction is to be taken into account; with extraterrestrial observations detectors may be used which are absolutely calibrated in a radiation laboratory under space conditions.

scholarly journals The time course of the heat effects in rapid chemical changes. Part I. - Apparatus and methods. Part II. - Some reactions of acids, bases, amino-acids and proteins

1930 ◽  
Vol 106 (743) ◽  
pp. 251-252 ◽  
Keyword(s):  
Amino Acids ◽  
Chemical Reactions ◽  
Time Course ◽  
Absolute Temperature ◽  
Chemical Changes ◽  
Sources Of Error ◽  
Heat Effects ◽  
Extensive Test ◽  
The Absolute

(1) The method of Hartridge and Roughton for following the velocity of rapid chemical reactions has been extended to the measurement of the amount of heat liberated in rapid reactions within periods of 0.01 second or less from the commencement of such reactions. For this purpose it has been necessary to carry out an extensive test of the physical sources of error involved in the measurement of temperature of rapidly moving fluids by means of thermojunctions. As the result of numerous controls and computations it is concluded that with the apparatus described in the text it is possible to measure the absolute temperature of the fluid travelling down the observation tube of the Hartridge-Roughton apparatus to an accuracy of 0.001° C. This claim is confirmed by experiments on the heat evolved in numerous rapid reactions, the values obtained agreeing very closely with the standard accepted values of the heat of such reactions.

The elements of the thermodynamic structure of the tropical atmosphere

2020 ◽  
Author(s):  
Jiawei Bao ◽  
Bjorn Stevens
Keyword(s):  
Gravity Waves ◽  
Large Scale ◽  
Vertical Structure ◽  
Absolute Temperature ◽  
Adiabatic Process ◽  
Tropical Atmosphere ◽  
Large Scale Circulation ◽  
Thermodynamic Structure ◽  
The Absolute ◽  
Virtual Temperature

<p>Deep convection plays an important role in driving the large-scale circulation and the complex interaction between moist convection and the large-scale circulation regulates the thermodynamic structure of the tropical atmosphere.<span> </span></p><p>The convectional thoughts of the thermodynamic structure of the tropical atmosphere are that the horizontal temperature in the free troposphere is homogeneous, which is referred to as weak temperature gradient (WTG), while the vertical structure follows a moist-adiabatic lapse rate. However, it is not known how accurate WTG holds and which moist- adiabatic process the tropical atmosphere indeed experiences. This study centers around the horizontal and vertical structure of the tropical atmosphere and uses the global storm resolving simulations (GSRMs) from ICON at 2.5 km to investigate them</p><p>The virtual effect or the vapor buoyancy effect arises from that the molecular weight of water vapor is much smaller than that of dry air. With the same pressure and temperature, this virtual effect makes moist air lighter than dry air. As the horizontal buoyancy differences are eliminated by convection gravity waves, virtual temperature, a temperature variable including the moisture conditions, is expected to be homogeneous. Then, to obtain a homogeneous virtual temperature horizontally, the absolute temperature has to change to accommodate the horizontal moisture difference. The model results show that virtual temperature is relatively homogeneous at mid- and lower troposphere. Therefore, the virtual effect plays a very important role in the horizontal temperature structure, making the absolute temperature colder in moist regions and warmer in dry regions. However, in the upper troposphere, both the absolute temperature and the virtual temperature are not homogeneous, and vary as a function of moisture, indicating a weakening influence of convection gravity waves there.</p><p>We use saturation equivalent potential temperature (theta-es) to explore the vertical structure of the tropical atmosphere. Theta-es is expected to be conserved above the lifting condensation level (LCL) if calculated following the exact moist-adiabatic process that tropical atmosphere undergoes. The pseudo-adiabat and the reversible-adiabat with the effect of condensate loading are compared. To minimize the horizontal differences in theta-es due to moisture, we also define theta-es to account for the virtual effect and the condensate loading effect. The model results suggest that the actual moist-adiabatic process that tropical atmosphere experiences is between the pseudo-adiabat and the reversible-adiabat with the effect of condensate loading assuming air parcels originating from 972 hPa.<span> </span></p><p>The above results are broadly consistent with the results from ERA5 reanalysis.</p>

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