scholarly journals Unit of Specific Entropy

2020 ◽  
Author(s):  
Keyword(s):  
Specific Entropy

scholarly journals Study on a Quaternary Working Pair of CaCl2-LiNO3-KNO3/H2O for an Absorption Refrigeration Cycle

Entropy ◽  
2019 ◽  
Vol 21 (6) ◽  
pp. 546 ◽  
Author(s):  
Yiqun Li ◽  
Na Li ◽  
Chunhuan Luo ◽  
Qingquan Su
Keyword(s):  
Heat Capacity ◽  
Crystallization Temperature ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Specific Enthalpy ◽  
Refrigeration Cycle ◽  
Absorption Refrigeration ◽  
Evaporation Temperature ◽  
Corrosion Rates ◽  
Specific Entropy

When compared with LiBr/H2O, an absorption refrigeration cycle using CaCl2/H2O as the working pair needs a lower driving heat source temperature, that is, CaCl2/H2O has a better refrigeration characteristic. However, the crystallization temperature of CaCl2/H2O solution is too high and its absorption ability is not high enough to achieve an evaporation temperature of 5 °C or lower. CaCl2-LiNO3-KNO3(15.5:5:1)/H2O was proposed and its crystallization temperature, saturated vapor pressure, density, viscosity, specific heat capacity, specific entropy, and specific enthalpy were measured to retain the refrigeration characteristic of CaCl2/H2O and solve its problems. Under the same conditions, the generation temperature for an absorption refrigeration cycle with CaCl2-LiNO3-KNO3(15.5:5:1)/H2O was 7.0 °C lower than that with LiBr/H2O. Moreover, the cycle’s COP and exergy efficiency with CaCl2-LiNO3-KNO3(15.5:5:1)/H2O were approximately 0.04 and 0.06 higher than those with LiBr/H2O, respectively. The corrosion rates of carbon steel and copper for the proposed working pair were 14.31 μm∙y−1 and 2.04 μm∙y−1 at 80 °C and pH 9.7, respectively, which were low enough for engineering applications.

The steady two-dimensional reflexion of an oblique partly dispersed shock wave from a plane wall

1973 ◽  
Vol 61 (1) ◽  
pp. 159-172 ◽  
Author(s):  
H. Buggisch
Keyword(s):  
Shock Wave ◽  
Internal State ◽  
Plane Wall ◽  
Plane Shock ◽  
Two Dimensional ◽  
State Variables ◽  
Reflected Shock ◽  
Internal State Variables ◽  
Specific Entropy ◽  
Instantaneous Values

The steady two-dimensional problem of reflexion of an oblique partly dispersed plane shock wave from a plane wall is studied analytically. Viscosity, diffusion and heat conduction are neglected. The thermodynamic state of the gas is assumed to be determined by the instantaneous values of the specific entropy s, pressure p and a finite number of internal state variables. Results for the flow field behind the reflected shock are obtained by a perturbation method which is based on the assumption that the influence of relaxation is relatively weak.

ANALYSIS OF THE LASER PROCESS WITH THREE DIFFERENT INITIAL STATES

2014 ◽  
Vol 28 (08) ◽  
pp. 1450029 ◽  
Author(s):  
FUYI YOU ◽  
JUNHUA CHEN ◽  
HONGYI FAN
Keyword(s):  
Photon Number ◽  
Entangled State ◽  
State Representation ◽  
Evolution Law ◽  
Laser Process ◽  
Specific Entropy ◽  
Degree Of Coherence ◽  
The Common ◽  
The Mean ◽  
Initial States

We analyze the laser process with three different initial states using the entangled state representation, obtain the evolution law of the mean photon number, the entropy, the specific entropy, the second degree of coherence and the Wigner functions, and find out the common characteristics of these three processes.

Exergy Analysis for the Performance Evaluation of Different Setups of the Secondary Air System of Aircraft Gas Turbines

2007 ◽  
Author(s):  
Philipp W. Zeller ◽  
Stephan Staudacher
Keyword(s):  
Performance Evaluation ◽  
Gas Turbines ◽  
Exergy Analysis ◽  
Entropy Increase ◽  
Engine Efficiency ◽  
Specific Entropy ◽  
Air System ◽  
Exergy Method ◽  
Secondary Air ◽  
Careful Design

Secondary Air System related losses in aircraft gas turbines cannot be directly assessed and quantified as possible for other sub-systems of the engine. If a particular setup is to be evaluated and compared to other, competing designs, it is required to have a distinct understanding of the loss mechanisms and the way these losses appear in the cycle. The relevant loss phenomena are therefore discussed in detail and are quantified with regard to the respective specific entropy increase. The exergy method is found to be the method of choice, since it holds some important advantages compared to other loss accounting methods like gas horsepower or thrust work potential. An exergy analysis is carried out for a high TET, two shaft engine of the medium thrust range. A comparison of setups with different compressor offtake positions is performed. It is found that the contribution of Air System related losses to overall engine efficiency deficits is significant, but may be reduced by careful design.

Specific entropy and the sign of the energy

1982 ◽  
Vol 26 (4) ◽  
pp. 950-953 ◽  
Author(s):  
Jacob D. Bekenstein
Keyword(s):  
Specific Entropy

Entropy Approach in the Analysis of Anisotropy of Digital Images

2002 ◽  
Vol 09 (03) ◽  
pp. 239-250 ◽  
Author(s):  
Eugenia N. Kirsanova ◽  
Michael G. Sadovsky
Keyword(s):  
Test Object ◽  
Digital Images ◽  
Arithmetic Mean ◽  
Information Capacity ◽  
Specific Entropy ◽  
Different Dimensions ◽  
The Difference

Anisotropy is assumed to be the difference of a plane object observed in different dimensions. For digital images, anisotropy is determined in two ways. The first one is based on the comparison of mosaics bearing rectangular smalts developed in different (perpendicular, to be exact) directions. The comparison is provided through an intermediate mosaic called palette, that is the mosaic with the frequency of smalts equal to arithmetic mean of the frequency of smalts of compared mosaics. The latter is based on the calculation of the information capacity of the mosaics developed in different directions. The information capacity is the specific entropy of real mosaic calculated against the reconstructed one bearing the most probable expansions of smaller smalts. The problem of test object is discussed.

scholarly journals Applying N-gram Alignment Entropy to Improve Feature Decay Algorithms

2017 ◽  
Vol 108 (1) ◽  
pp. 245-256 ◽  
Author(s):  
Alberto Poncelas ◽  
Gideon Maillette de Buy Wenniger ◽  
Andy Way
Keyword(s):  
Machine Translation ◽  
English Translation ◽  
Data Selection ◽  
Test Set ◽  
Specific Entropy ◽  
Decay Factor ◽  
N Gram ◽  
Training Examples ◽  
Linear Decay

AbstractData Selection is a popular step in Machine Translation pipelines. Feature Decay Algorithms (FDA) is a technique for data selection that has shown a good performance in several tasks. FDA aims to maximize the coverage of n-grams in the test set. However, intuitively, more ambiguous n-grams require more training examples in order to adequately estimate their translation probabilities. This ambiguity can be measured by alignment entropy. In this paper we propose two methods for calculating the alignment entropies for n-grams of any size, which can be used for improving the performance of FDA. We evaluate the substitution of the n-gram-specific entropy values computed by these methods to the parameters of both the exponential and linear decay factor of FDA. The experiments conducted on German-to-English and Czech-to-English translation demonstrate that the use of alignment entropies can lead to an increase in the quality of the results of FDA.

Rotating fluid masses in general relativity. II

1966 ◽  
Vol 62 (3) ◽  
pp. 495-501 ◽  
Author(s):  
R. H. Boyer
Keyword(s):  
General Relativity ◽  
Variational Principle ◽  
First Integrals ◽  
Constant Angular Velocity ◽  
Hydrodynamic Equations ◽  
Rotating Fluid ◽  
Axially Symmetric ◽  
Field Equations ◽  
Full Field ◽  
Specific Entropy

AbstractWe describe some properties of a stationary, isolated, axially symmetric, rotating body of perfect fluid, according to general relativity. We first specialize to the case of constant specific entropy and constant angular velocity. The latter condition is equivalent to rigidity in the Born sense; both conditions are consequences of a simple variational principle. The hydrodynamic equations can then be integrated completely. Analogous first integrals are given also for the case of differential rotation. No use is made of the full field equations.

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