Thermodynamic Properties of Liquid Alkali Metals Using a Charged Hard, Sphere Reference System

this journal now available and free download able at Chinese journal of physics, written by P. B. Thakor, V. N. Patel, P. N. Gajjar, and A. R. Jani from Department of Physics, Sardar Patel University, Gujarat, India, introduce The Gibbs-Bogoliubov (GB) inequality, the experiment results : Structure of liquid metals,Thermodynamic properties,Pseudopotential method.

abstraction

The Gibbs-Bogoliubov (GB) inequality is used to evaluate the Helmholtz free energy of
liquid alkali metals as a function of temperature. The structural contribution to the Helmholtz free energy is investigated by adopting a charged hard sphere fluid model. A well established single parametric local pseudopotential is applied to describe the electron-ion interaction along with five different local field correction functions viz; Hartree, Taylor, Ichimaru and Utsumi, Farid et al., and Sarkar et al., 6.2% to 51.15% of the influence on the Helmholtz free energy is concluded to be due to these local field correction functions with respect to the static Hartree dielectric function. Very good agreement with experimental results is achieved.
PACS. 61.25.M – Structure of liquid metals.
PACS. 65.50.+m – Thermodynamic properties.
PACS. 71.15.Hx – Pseudopotential method.

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engineering thermodynamic steam and gas turbine power plant

The gas-turbine operates on the principle of the Brayton cycle, where compressed air is mixed with fuel, and burned under constant pressure conditions. The resulting hot gas is allowed to expand through a turbine to perform work. In a 33% efficient gas-turbine approximately two / thirds of this work is spent compressing the air, the rest is available for other work

download more at
http://www.freestudy.co.uk/thermodynamics/t9109.pdf

at this link you will also can see some thermodynamic calculation for steam and gas turbine.

System and Boundary in thermodynamic

A thermodynamic system is defined as a quantity of matter or a region in space chosen for analysis,

surrounding or environment
is can defined as the mass or region outside the system or everything external to the system

boundary

The closed surface that separates the system from its surroundings, through which energy and mass may enter or leave the system.
Boundaries can be fixed or movable Boundaries can be real (cylinder walls and piston surfaces in an internal combustion engine) , In many cases, a thermodynamic analysis must be made of a device, such as a heat exchanger, that involves a flow of mass into and/or out of the device.
Boundaries can also be imaginary (cross sections of pipes at the entrance and exit of turbines)
It is possible to subdivide a system into subsystems, or to group several systems together into a larger system



Thermodynamic System Types
There are three kinds of systems depending on the kinds of exchanges taking place between a thermodynamic system and its environment : isolated, closed and open system

isolated systems: is one with rigid walls that has no communication (i.e., no heat, mass,or work transfer) with its surroundings. An example of an isolated system would be an insulated container, such as an insulated gas cylinder

closed systems: system is one in which the system mass cannot cross the boundary, but energy
can (heat or work). A greenhouse is an example of a closed system exchanging heat but not work with its environment. Whether a system exchanges heat, work or both is usually thought of as a property of its boundary, which can be
adiabatic boundary: not allowing heat exchange;
rigid boundary: not allowing exchange of work
so we can get conclusion the important point of closed system are :

• Consists of a fixed amount of mass
  
• No mass can cross its boundary
  
• No mass can enter or leave a closed system Volume does not have to be fixed
  
• But energy, in the form of heat or work can cross the boundary
  
• when the piston rises, the boundary of the system moves Heat and work crosses the boundary of the system during this process but not mass
  

open systems:system is one in which mass can cross the system boundary in addition to energy. A boundary allowing matter exchange is called permeable. The ocean would be an example of an open system
so we can get conclusion the important point of closed system are :

• The procedure in such an analysis is to specify control volume that surrounds the device under consideration
  
• The boundaries of a control volume are called a control surface
  
• Mass as well as heat and work can flow across the control surface
  

from picture below we can see open system and closed system, where even energy is not
allowed to cross the boundary in closed system, that system is called an isolated system.