Abstract A convergent-divergent (CD) nozzle is the key component in an rocket propulsion system. The relations of the processes inside a CD nozzle and chamber furnish the mathematical tools needed to calculate the performance and determine several of the key design parameters of propulsion systems. They are useful as a means of evaluating and comparing the performance of various rocket systems; they permit the prediction of the operating performance of any rocket unit that uses the thermodynamic expansion of a gas, and the determination of several necessary design parameters, such as nozzle size and generic shape, for any given performance requirement. This theory applies to chemical rocket propulsion systems (both liquid and solid propellant
Chapter 11: Particulate Model of Matter 11.1 Particulate Model of Matter Particulate Model of Matter suggests that: * All matter is made up of small discrete particles. * The small discrete particles in matter are in constant random motion. It is easier to explain the Particulate model of matter using models. A variety of objects can be used to represent the small discrete particles in matter. 11.2 Particulate Model for Solids, Liquids and Gases A block of ice Solid molecules have a restricted motion = Solid A beaker of boiling water Gas molecules are able to move at extremely high speed = Gas A beaker of warm water liquid molecules have greater mobility = Liquid States of Matter Solid * In solids, the molecules are arranged close together in a regular pattern * Strong attractive intermolecular forces hold the molecules in position so they have definite shape and volume * They can only vibrate in their fixed positions Liquid * In liquids, the molecules are not arranged in a regular pattern and are slightly further apart then those in solids * The attractive intermolecular forces are not very strong.
An optimised imaging modality would result from a combination of these properties. One such emerging technique that achieves this is Cherenkov Luminescence Imaging (CLI). CLI harnesses Cherenkov radiation to image radionuclides using OI instruments2. Cherenkov radiation is a well known phenomenon that arises when charged particles, such as β- or β+ travel through an optically transparent material with a velocity that exceeds the speed of light in the material. As the particle travels through the medium it loses kinetic energy by polarizing the electrons of the given material.
Heat flows from the warmer to the cooler object until they are both at the same temperature. Conduction is the movement of heat through a substance by the collision of molecules. At the place where the two object touch, the faster-moving molecules of the warmer object collide with the slower moving molecules of the cooler object. As they collide, the faster molecules give up some of their energy to the slower molecules. The slower molecules gain more thermal energy and collide with other molecules in the cooler object.
A. Heat travels fastest by convection through a gas. B. Heat increases the temperature of a subtance. C. Heat can travel through solids, liquids and gases.
Diffusion, Osmosis and Active transport. Diffusion: Seeing that substances have kinetic energy (energy of motion), they are continuously moving around, colliding with one another, and moving in various directions. The random mixing of ions and molecules due to their kinetic energy is called diffusion. If a particular ion or molecule is present in an area where there is a lot of that particular molecule, it would be in a high concentration area of itself. All the molecules would then collide with each other due to their kinetic energy, eventually forcing themselves away from each other, where there is more space.
Longitudinal wave The vibrations of the object set particles in the surrounding medium in vibrational motion, thus transporting energy through the medium. For a sound wave traveling through air, the vibrations of the particles are best described as longitudinal. Longitudinal waves are waves in which the motion of the individual particles of the medium is in a direction that is parallel to the direction of energy transport. Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves. As the vibrating string moves in the forward direction, it begins to push upon surrounding air molecules, moving them to the right towards their nearest neighbor.
Heat Capacity... The Heat Capacity itself is extensive (scales with the size of system), but we can think of making this quantity intensive (making it an intrinsic property of the material) by defining related quantities: the Molar Heat Capacity is defined as the Heat Capacity of a homogeneous pure compound (or element) divided by the the number of moles of that compound (or element) the Specific Heat is defined as the Heat Cpacity of a homogeneous sample divided by its mass. The Heat Capacity of any substance is positive. The Heat Capacity is discontinuous at phase transitions. For a gas, the Heat capacity depends on how one does the heating.
(Hence its utility to solution-phase chemists, including biochemists.) The Helmholtz free energy has a special theoretical importance since it is proportional to the logarithm of the partition function for the canonical ensemble in statistical mechanics. (Hence its utility to physicists; and to gas-phase chemists and engineers, who do not want to ignore pdV work.) The historically earlier
The effect of heat on the expansion of gases is stated in Charles' Law. A gas occupies 1/273.15 more space for each 1° C. rise in temperature and, conversely, 1/273.15 less space for each 1° C. drop in temperature. This fact enabled scientists to determine absolute zero (-273.15° C.), the temperature at which all molecules theoretically stop moving. A gas can be made to expand without the addition of outside heat if the pressure confining the gas is reduced. This principle is stated in Boyle's Law.