scholarly journals XXVIII.—On the Computation of the Specific Heat of Liquid Water at various Temperatures, from the Experiments of M. Regnault

1853 ◽  
Vol 20 (3) ◽  
pp. 441-444
Author(s):  
William John Macquorn Rankine
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Low Temperature ◽  
Specific Heat ◽  
Liquid Water ◽  
Hot Water ◽  
Different Temperatures ◽  
Apparent Specific Heat ◽  
The Mean ◽  
Great Force

Correction of M. Regnault's Experiments for the Effect of Agitation.The discovery by Mr Joule of the fact, that mechanical power expended in the agitation of liquids is converted into heat as the visible agitation subsides, renders a certain correction necessary in calculating the results of experiments on specific heat in which such agitation has occurred.Of this kind are the experiments of M. Regnault on the apparent specific heat of liquid water at different temperatures. Water at a high temperature, T3, was emitted from a boiler into a calorimeter containing water at a low temperature, Tl, and the resulting intermediate temperature of the whole mass, T2, was used as the means of calculating the ratio of the mean specific heat of water between T3 and T2, to its mean specific heat between T2 and T1. Now, the upper part of the boiler contained steam at a high pressure, so that the hot water was expelled with great force.

scholarly journals 2. On the Computation of the Specific Heat of Liquid Water, at various Temperatures, from the experiments of M. Regnault.

1857 ◽  
Vol 3 ◽  
pp. 90
Author(s):  
W. J. Macquorn Rankine
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Specific Heat ◽  
Liquid Water ◽  
Low Temperatures ◽  
Fluid Friction ◽  
Made In

The experiments of M. Regnault having been made by introducing water at a high temperature from a boiler into a calorimeter, containing water at a low temperature, and power exercised by the steam in the boiler in expelling the water was converted into heat by fluid friction, thus producing a rise of temperature in the calorimeter, for which allowance ought to be made in calculating the specific heat of liquid water from each experiment. Mr Joule's determination of the dynamical value of the specific heat of liquid water at low temperatures affords the means of calculating the correction required in each case.

scholarly journals GERMINATION AND VIGOUR IN SEEDS OF THE COWPEA IN RESPONSE TO SALT AND HEAT STRESS

2019 ◽  
Vol 32 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Luma Rayane de Lima Nunes ◽  
Paloma Rayane Pinheiro ◽  
Charles Lobo Pinheiro ◽  
Kelly Andressa Peres Lima ◽  
Alek Sandro Dutra
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
High Temperature ◽  
Low Temperature ◽  
Vigna Unguiculata ◽  
Salt Concentration ◽  
Dry Weight ◽  
Germination Percentage ◽  
Different Types ◽  
Different Temperatures

ABSTRACT Salinity is prejudicial to plant development, causing different types of damage to species, or even between genotypes of the same species, with the effects being aggravated when combined with other types of stress, such as heat stress. The aim of this study was to evaluate the tolerance of cowpea genotypes (Vigna unguiculata L. Walp.) to salt stress at different temperatures. Seeds of the Pujante, Epace 10 and Marataoã genotypes were placed on paper rolls (Germitest®) moistened with different salt concentrations of 0.0 (control), 1.5, 3.0, 4.5 and 6.0 dS m-1, and placed in a germination chamber (BOD) at temperatures of 20, 25, 30 and 35°C. The experiment was conducted in a completely randomised design, in a 3 × 4 × 5 scheme of subdivided plots, with four replications per treatment. The variables under analysis were germination percentage, first germination count, shoot and root length, and total seedling dry weight. At temperatures of 30 and 35°C, increases in the salt concentration were more damaging to germination in the Epace 10 and Pujante genotypes, while for the Marataoã genotype, damage occurred at the temperature of 20°C. At 25°C, germination and vigour in the genotypes were higher, with the Pujante genotype proving to be more tolerant to salt stress, whereas Epace 10 and Marataoã were more tolerant to high temperatures. Germination in the cowpea genotypes was more sensitive to salt stress when subjected to heat stress caused by the low temperature of 20°C or high temperature of 35°C.

Study of high-pressure air jet controlled compression ignition with compound thermodynamic cycle for combustion and emission formation process

2020 ◽  
pp. 146808742096933
Author(s):  
Xiangyu Meng ◽  
Sicheng Liu ◽  
Jingchen Cui ◽  
Jiangping Tian ◽  
Wuqiang Long ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Low Temperature ◽  
Formation Process ◽  
Combustion Process ◽  
Thermodynamic Cycle ◽  
Compression Ignition ◽  
Temperature Reaction ◽  
Air Jet ◽  
High Temperature Reaction

A novel method called high-pressure air (HPA) jet controlled compression ignition (JCCI) based on the compound thermodynamic cycle was investigated in this work. The combustion process of premixed mixture can be controlled flexibly by the high-pressure air jet compression, and it characterizes the intensified low-temperature reaction and two-stage high-temperature reaction. The three-dimensional (3D) computational fluid dynamics (CFD) numerical simulation was employed to study the emission formation process and mechanism, and the effects of high-pressure air jet temperature and duration on emissions were also investigated. The simulation results showed that the NOx formation is mainly affected by the first-stage high-temperature reaction due to the higher reaction temperature. Overall, this combustion mode can obtain ultra-low NOx emission. The second-stage high-temperature reaction plays an important role in the CO and THC formation caused by the mixing effect of the high-pressure air and original in-cylinder mixture. The increasing air jet temperature leads to a larger high-temperature in-cylinder region and more fuel in the first-stage reaction, and therefore resulting in higher NOx emission. However, the increasing air jet temperature can significantly reduce the CO and THC emissions. For the air jet duration comparisons, both too short and too long air jet durations could induce higher NOx emission. A higher air jet duration would result in higher CO emission due to the more high-pressure air jet with relatively low temperature.

A Method for Predicting the Behavior of Plastics at Different Temperatures

2014 ◽  
Vol 1039 ◽  
pp. 107-111
Author(s):  
Yang Chen ◽  
Gui Qin Li ◽  
Bin Ruan ◽  
Xiao Yuan ◽  
Hong Bo Li
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Constitutive Model ◽  
Research And Development ◽  
Mechanical Behavior ◽  
Plastic Material ◽  
Different Temperatures ◽  
Plastic Parts

The mechanical behavior of plastic material is dramatically sensitive to temperature. An method is proposed to predict the mechanical behavior of plastics for cars, ranging from low-temperature low temperature ≤-40°C to high temperature ≥80°C. It dominates the behavior of plastic material based on improved constitutive model in which the parameters adjusted by a series of tests under different temperatures. The method is validated with test and establishes the basis for research and development of plastic parts for automobile as well.

4. On the Mechanical Action of Heat. Note as to the Dynamical Equivalent of Temperature in Liquid Water, and the Specific Heat of Atmospheric Air and Steam.

1857 ◽  
Vol 3 ◽  
pp. 5-8
Author(s):  
W. J. Macquorn Rankine
Keyword(s):  
Specific Heat ◽  
Liquid Water ◽  
Constant Pressure ◽  
Mechanical Action ◽  
Atmospheric Air ◽  
Apparent Specific Heat

In the author's paper on the Mechanical Action of Heat (Trans. Roy. Soc. Edin., Vol. XX., Part I), the calculations depending on the dynamical equivalent of temperature in liquid water were founded on the experiments of De la Roche and Bérard on the ratio of the apparent specific heat of atmospheric air under constant pressure to that of water. The equivalent thus obtained was about one-tenth part less than Mr Joule's. Since then, the author, having become acquainted with the details of Mr Joule's experiments, has come to the conclusion that Mr Joule's equivalent is correct to aboutof its amount, and that the discrepancy in question originates chiefly in the experiments of De la Roche and Bérard.

High Temperature and High Pressure ESP Performance Testing System Design

2013 ◽  
Vol 457-458 ◽  
pp. 423-427
Author(s):  
Xiao Qing Li ◽  
Xiao Yan Liu
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Heat Exchange ◽  
Liquid State ◽  
Constant Pressure ◽  
Hot Water ◽  
Testing System ◽  
Friction Resistance ◽  
High Temperature And Pressure ◽  
Temperature And Pressure

With the development of oilfield exploration, the performance of electric submersible pump (ESP) has been enhanced very fast. It requires testing techniques develop at the same time. The most outstanding question is the testing of high temperature and pressure ESP. A testing well was drilled in Daqing in 1992. It keeps the water liquid state on 150 centigrade by high pressure. This system can simulate operational mode 3000 meters under the ground. But many new ESPs have been produced these years. The quondam testing system couldnt meet the testing requirement. A new testing system is desiderated eagerly. This paper developed a high temperature and pressure ESP testing experimentation system. Hydraulic/thermodynamic analysis calculation has been carried on. Friction resistance from constant pressure point to the suction inlet of hot water pump and the ESP in heating-forced cycle and experimentation primary cycle are calculated respectively. Keeping the water liquid state on 180 centigrade, constant pressure value was fixed on 2.5 MPa. The heat load is calculated including the heat that the water in the system and the equipment need and the heat loss. In order to protect ESP from emanating too much heat to keep the temperature and pressure of the system steady, heat exchange system has been designed. Cold load and heat exchange square have been calculated. Friction resistance and the size of the cold water cistern have been calculated. These provide necessary academic foundation for the testing experimentation of high temperature and pressure ESP.

Fermi–Dirac Statistics

2019 ◽  
pp. 386-403
Author(s):  
Robert H. Swendsen
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Specific Heat ◽  
Fermi Energy ◽  
Fermi Gas ◽  
Main Application ◽  
Densities Of States ◽  
Low Temperature Specific Heat ◽  
Very High ◽  
The Ideal

The main application of Fermi–Dirac Statistics is to calculate the properties of electrons. This chapter explains how the properties of fermions account for the behavior of metals. The Fermi energy is introduced and shown to correspond to a very high temperature, so that most properties can be obtained from low-temperature expansions. Both discrete and continuous densities of states are discussed. The Sommerfeld expansion is derived explicitly. The low-temperature specific heat and compressibility are derived. The most important fermions are electrons, and understanding the properties of electrons is central to understanding the properties of all materials. In this chapter we will study the ideal Fermi gas, which turns out to explain many of the properties of electrons in metals.

scholarly journals VIII.—Note as to the Dynamical Equivalent of Temperature in Liquid Water, and the Specific Heat of Atmospheric Air and Steam, being a Supplement to a Paper On the Mechanical Action of Heat

1853 ◽  
Vol 20 (2) ◽  
pp. 191-193
Author(s):  
William John Macquorn Rankine
Keyword(s):  
Cast Iron ◽  
Specific Heat ◽  
Liquid Water ◽  
Royal Society ◽  
Constant Pressure ◽  
Mechanical Action ◽  
Numerical Results ◽  
Detailed Account ◽  
Atmospheric Air ◽  
Apparent Specific Heat

(33*.) In my paper on the Mechanical Action of Heat, published in the 1st Part of the 20th Volume of the Transactions of the Royal Society of Edinburgh, some of the numerical results depend upon the dynamical equivalent of a degree of temperature in liquid water. The value of that quantity which I then used, was calculated from the experiments of De la Roche and Bérard on the apparent specific heat of atmospheric air under constant pressure, as compared with liquid water.The experiments of Mr Joule on the production of heat by friction, give, for the specific heat of liquid water, an equivalent about one-ninth part greater than that which is determined from those of De la Roche and Bérard. I was formerly disposed to ascribe this discrepancy in a great measure to the smallness of the differences of temperature measured by Mr Joule, and to unknown causes of loss of power in his apparatus, such as the production of sound and of electricity; but, subsequently to the publication of my paper, I have seen the detailed account of Mr Joule's last experiments in the Philosophical Transactions for 1850, which has convinced me, that the uncertainty arising from the smallness of the elevations of temperature, is removed by the multitude of experiments (being forty on water, fifty on mercury, and twenty on cast iron); that the agreement amongst the results from substances so different, shews that the error by unknown losses of power is insensible, or nearly so; and that the necessary conclusion is, that the dynamical value assigned by Mr Joule to the specific heat of liquid water, viz.:—772 feet per degree of Fahrenheit, does not err by more than two or at the utmost, three feet; and therefore, that the discrepancy originates chiefly in the experiments of De la Roche and Bérard.

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