5. On the Thermoelectric Properties of Iron

1889 ◽  
Vol 15 ◽  
pp. 127-129
Author(s):  
Tait

For some time Signor Battelli has been engaged, with remarkable success, in measuring directly the amount of the ‘Thomson effect’ in various metals.With the exception of iron, the common metals have given him results coinciding as closely as could be expected with those I found in 1872 by an indirect method. Among other particularly satisfactory things, he has directly verified the first of the two changes of sign of the Thomson effect in nickel. And I think it will be allowed that what I introduced long ago as a mere working hypothesis,–that the Thomson effect is directly proportional to the absolute temperature,–if it was not completely established as a fact by my own experiments, has been made absolutely certain by the recent work of Campbell and of Battelli.

Author(s):  
Sarah E. Murray

This book gives a compositional, truth‐conditional, crosslinguistic semantics for evidentials set in a theory of the semantics for sentential mood. Central to this semantics is a proposal about a distinction between what propositional content is at‐issue, roughly primary or proffered, and what content is not‐at‐issue. Evidentials contribute not‐at‐issue content, more specifically what I will call a not‐at‐issue restriction. In addition, evidentials can affect the level of commitment a sentence makes to the main proposition, contributed by sentential mood. Building on recent work in the formal semantics of evidentials and related phenomena, the proposed semantics does not appeal to separate dimensions of illocutionary meaning. Instead, I argue that all sentences make three contributions: at‐issue content, not‐at‐issue content, and an illocutionary relation. At‐issue content is presented, made available for subsequent anaphora, but is not directly added to the common ground. Not‐at‐issue content directly updates the common ground. The illocutionary relation uses the at‐issue content to impose structure on the common ground, which, depending on the clause type (e.g., declarative, interrogative), can trigger further updates. Empirical support for this proposal comes from Cheyenne (Algonquian, primary data from the author’s fieldwork), English, and a wide variety of languages that have been discussed in the literature on evidentials.


1967 ◽  
Vol 1 ◽  
pp. 14-22

‘The best poem of the best poet’, said Dryden. And Spence (a generation or so later): ‘The most beautiful and most correct poem that ever was wrote in the Roman language.’ It is not hard to see why the Georgics had such a powerful appeal to the English Augustans, nor why the English Georgic became a poetic genre in its own right in the eighteenth century. The absolute control of the medium, the perfection of finish such as we do not find uniformly in the unrevised Aeneid, put it alongside Horace’s Odes as an example of artistic excellence of the highest degree. The elaborate diction, with its elevation of the ordinary and the common into ornate and cultivated paraphrase, naturally pleased those whose ears were attuned to listen for elegance, dignity, and propriety.


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.


1973 ◽  
Vol 95 (2) ◽  
pp. 236-241
Author(s):  
T. F. Ford ◽  
C. R. Singleterry

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.


2021 ◽  
Vol 33 (2) ◽  
pp. 9-19
Author(s):  
V. VIJAYAKUMAR ◽  

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.


2003 ◽  
Vol 83 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Goran Andjelkovic

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.


1992 ◽  
Vol 9 ◽  
pp. 297-298
Author(s):  
G. Sironi ◽  
G. Bonelli ◽  
M. Gervasi

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.


Geosciences ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 286
Author(s):  
Paolo Galli

The Italian seismic compilations are among the most complete and back-in time extended worldwide, with earthquakes on record even before the Common Era. However, we have surely lost the memory of dozen strong events of the historical period, mostly in the first millennium CE. Given the lack of certain or conclusive written sources, besides paleoseismological investigations, a complementary way to infer the occurrence of lost earthquakes is to cross-check archaeoseismic evidence from ancient settlements. This usually happens by investigating collapses/restorations/reconstructions of buildings, the general re-organization of the urban texture, or even the abrupt abandonment of the settlement. Exceptionally, epigraphs mentioning more or less explicitly the effects of the earthquake strengthened the field working hypothesis. Here, I deal with both paleoseismological clues from the Monte Marzano Fault System (the structure responsible for the catastrophic, Mw 6.9 1980 earthquake) and archaeoseismological evidence of settlements founded in its surroundings to cast light on two poorly known earthquakes that occurred at the onset and at the end of the first millennium CE, likely in 62 and in 989 CE. Both should share the same seismogenic structure and the size of the 1980 event (Mw 6.9).


2013 ◽  
Vol 1490 ◽  
pp. 179-184
Author(s):  
Tse-Hsiao Li ◽  
Jenn-Dong Hwang ◽  
Hsu-Shen Chu ◽  
Chun-Mu Chen ◽  
Chia-Chan Hsu ◽  
...  

ABSTRACTOwing to energy conservation of waste heat, Lead telluride, PbTe, based materials have promising good thermoelectric properties around a range of middle temperature (Fig. 1, from 300 to 600°C), due to their high melting point, fine chemical stability, and the high figure of merit Z. The general physical properties and factors affecting the figure of merit have been reviewed. This research is focused on the n-type of PbTe materials and collocated with analysis of densities, hardness, elastic modulus, and thermoelectric properties thermoelectric figure of merit ZT=GS2T/κ (where G is electrical conductivity, S is Seebeck coefficient , T is absolute temperature, and κ is thermal conductivity). Room temperature hardness and Young’s modulus are measured by nano-indentation. In this study, the hot-press compacts under the pressure of 4 ton/cm2 can reach the maximum density about 8.2 g/cm3, and hardness and elastic modulus are 0.6 GPa and 70 GPa, respectively. The figure of merit value (ZT) of PbTe in low temperature (around 340°C) was found about 1 with carrier concentration above 1019 cm−3. These results also indicate that the powder metallurgy parameters provide potentialities for further increase of the high efficiency of energy conversion in PbTe materials.


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.


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