2. Matter from the outside

2014 ◽  
pp. 22-37
Author(s):  
Peter Atkins
Keyword(s):  
Physical Chemistry ◽  
Free Energy ◽  
Gibbs Energy ◽  
Absolute Zero ◽  
Second Law ◽  
Conservation Of Energy ◽  
The Third ◽  
Laws Of Thermodynamics ◽  
Third Law

‘Matter from the outside’ focuses on the applications of thermodynamics in physical chemistry. Thermodynamics is the science of energy and the transformations that it can undergo. It plays a central role in understanding chemical reactions. There are four laws of thermodynamics: the Zeroth Law establishes the concept of temperature; the First Law concerns the conservation of energy; the Second Law deals with entropy (a measure of the quality of energy); and the Third Law concerns the absolute zero of temperature. The property enthalpy is explained along with Gibbs energy and free energy. Physical chemists can deploy the laws of thermodynamics, laws relating to matter from the outside, to establish relations between properties and to make important connections.

First and second laws of thermodynamics: relationship, “inconsistency”, hidden effects

2020 ◽  
pp. 63-73
Author(s):  
A. M. Savchenko ◽  
Yu. V. Konovalov ◽  
A. V. Laushkin
Keyword(s):  
Free Energy ◽  
Internal Energy ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Entropy Of Mixing ◽  
Ideal Mixing ◽  
Laws Of Thermodynamics ◽  
Relationship Of ◽  
The Relationship

The relationship of the first and second laws of thermodynamics based on their energy nature is considered. It is noted that the processes described by the second law of thermodynamics often take place hidden within the system, which makes it difficult to detect them. Nevertheless, even with ideal mixing, an increase in the internal energy of the system occurs, numerically equal to an increase in free energy. The largest contribution to the change in the value of free energy is made by the entropy of mixing, which has energy significance. The entropy of mixing can do the job, which is confirmed in particular by osmotic processes.

The Third Law of Thermodynamics

2018 ◽  
Author(s):  
Dennis Sherwood ◽  
Paul Dalby
Keyword(s):  
Absolute Zero ◽  
The Third ◽  
Third Law Of Thermodynamics ◽  
Third Law ◽  
The Absolute

The Third Law was introduced in Chapter 9; this chapter develops the Third Law more fully, introducing absolute entropies, and examining how adiabatic demagnetisation can be used to approach the absolute zero of temperature.

scholarly journals XVI. Some applications of dynamical principles to physical phenomena.—Part II

1887 ◽  
Vol 178 ◽  
pp. 471-526 ◽  
Keyword(s):  
Direct Application ◽  
Second Law ◽  
Conservation Of Energy ◽  
Laws Of Thermodynamics ◽  
William Thomson ◽  
Physical Phenomena ◽  
Dynamical Principle

1. The two laws of Thermodynamics have proved by far the most powerful, indeed almost the only, means we possess of connecting the phenomena in one branch of Physics with those in another. Though the two laws are usually grouped together, it should not be forgotten that they differ essentially in character. The First Law is a direct application to Physics of one of the most important dynamical principles, that of the Conservation of Energy; while the Second Law, which for the purpose of connecting various physical phenomena is even more important than the first, is not, strictly speaking, a dynamical principle at all, since its statement involves a reference to quantities which never occur in abstract Dynamics. Clausius and Sir William Thomson, the two physicists to whom the Second Law owes its importance, have connected it with other principles which seem more axiomatic.

On the Three Laws of Gearing

2002 ◽  
Vol 124 (4) ◽  
pp. 733-744 ◽  
Author(s):  
David B. Dooner
Keyword(s):  
Direct Contact ◽  
Angular Displacement ◽  
Geometric Theory ◽  
Gear Ratio ◽  
Second Law ◽  
The Third ◽  
Kinematic Geometry ◽  
Third Law ◽  
Conjugate Surfaces ◽  
Contact Mechanism

Three laws of gearing are presented in terms of a three link 1-dof spatial direct contact mechanism. The first law of gearing defines the instantaneous relationship between an infinitesimal displacement of an output body to an infinitesimal angular displacement of an input body for a specified tooth contact normal. A system of cylindroidal coordinates are introduced to facilitate a universal methodology to parameterize the kinematic geometry of generalized motion transmission between skew axes. The second law of gearing establishes a relation between the instantaneous gear ratio and the apparent radii of the hyperboloidal pitch surface in contact as parameterized using a system of cylindroidal coordinates. The third law of gearing establishes an instantaneous relationship for the relative curvature of two conjugate surfaces in direct contact and shows that this relation is independent of the tooth profile geometry. These three laws of gearing along with the system of cylindroidal coordinates establish, in part, a generalized geometric theory comparable to the existing theory for planar kinematics.

The Lex Agraria of 111 B.C. and Procedure in Legislative Assemblies

Antichthon ◽  
1978 ◽  
Vol 12 ◽  
pp. 45-50
Author(s):  
R. Develin
Keyword(s):  
Second Law ◽  
Land Distribution ◽  
The Third ◽  
The Poor ◽  
The Subject ◽  
Third Law ◽  
The Law ◽  
Land Holdings ◽  
Point Of Reference

Agrarian legislation in the immediate aftermath of the Gracchi is the subject of continuing debate. Appian (BC i 27) records three laws, the last two of which are specified as being tribunician: the first removed the inalienability of land holdings; the second was perhaps the measure of Sp. Thorius, mentioned also by Cicero, which stopped land distribution, confirmed possession rights on the land and imposed a rent, the proceeds of which were to help the poor; the third abolished this rent. Appian provides chronological clues of a sort: the first measure came ‘not long after’ the death of C. Gracchus, the third ‘not long after’ Thorius’ law, and the whole business was perhaps finished within fifteen years άπò τῆς Γράκχου νομοϑεσίας. I say ‘perhaps’ because it remains arguable whether the point of reference for these fifteen years is Tiberius or Gaius Gracchus. I intend to argue elsewhere that Tiberius is meant, but as such an argument cannot be regarded as conclusive, there is still a point in this respect in examining the lex agraria which is the inscription CIL i2 585. The law is naturally important in its own right. It is dated internally to 111 B.C. and attempts have been made to equate it with either the second or third of Appian’s laws. If it was the second, this allows a retention of the fifteen years and the placing of the third law in 109 or 108. But if Appian has accurately reported the second law, it imposed a rent, while the first part of the inscriptional law talks of removing rent.

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