Review of heat and water movement in field soils
... in the Davis experimental ®eld derived from the energy balance ®eld observations (solid line) is presented for one day (Cahill and Parlange, 1998). In addition the change in moisture content due to vapor ¯ux obtained with the Philip and de Vries diffusion formulation (short dashed) and the change du ...
... in the Davis experimental ®eld derived from the energy balance ®eld observations (solid line) is presented for one day (Cahill and Parlange, 1998). In addition the change in moisture content due to vapor ¯ux obtained with the Philip and de Vries diffusion formulation (short dashed) and the change du ...
Density and surface tension of liquid iron oxides
... expected from the oxygen pressure above the drop at the temperature T of the liquid. However, we have already remarked that the drop should present temperature gradients, particularly when the lasers are heating it. This point is easily revealed if we transform the beginning of the cooling curve of ...
... expected from the oxygen pressure above the drop at the temperature T of the liquid. However, we have already remarked that the drop should present temperature gradients, particularly when the lasers are heating it. This point is easily revealed if we transform the beginning of the cooling curve of ...
A new device for characterisation of the drainage kinetics of fibrous
... Another modified Schopper–Riegler device is Dynamic Filtration System (Roschy et al., 2003) which has only one central outflow cone. This apparatus is an important step towards adapting the Schopper– Riegler device for determination of gravity drainage kinetics of fibrous suspensions. In this appara ...
... Another modified Schopper–Riegler device is Dynamic Filtration System (Roschy et al., 2003) which has only one central outflow cone. This apparatus is an important step towards adapting the Schopper– Riegler device for determination of gravity drainage kinetics of fibrous suspensions. In this appara ...
Fundamentals of Chemical Engineering Thermodynamics
... Chapter 6 goes into applications of thermodynamics to chemical processes. The range of applications is limited to systems involving pure fluids, namely power plants and refrigeration/liquefaction systems. This is the part of the course that most directly relates to processes discussed in capstone des ...
... Chapter 6 goes into applications of thermodynamics to chemical processes. The range of applications is limited to systems involving pure fluids, namely power plants and refrigeration/liquefaction systems. This is the part of the course that most directly relates to processes discussed in capstone des ...
Second Law of Thermodynamics
... it limits the types of final states of the system that naturally evolve from a given initial state. The second law has many practical applications. For example it explains the limits of efficiency for heat engines and refrigerators. To develop a better understanding of this law, try these conceptual ...
... it limits the types of final states of the system that naturally evolve from a given initial state. The second law has many practical applications. For example it explains the limits of efficiency for heat engines and refrigerators. To develop a better understanding of this law, try these conceptual ...
Thermal Stresses - Rick Bradford Home Page
... [5] Convective boundary condition: In this case we do not know in advance either the temperature or the heat flux at the boundary. Instead the temperature of a fluid in contact with the boundary is specified. The heat flux into the surface of the solid is then specified via a heat transfer coefficie ...
... [5] Convective boundary condition: In this case we do not know in advance either the temperature or the heat flux at the boundary. Instead the temperature of a fluid in contact with the boundary is specified. The heat flux into the surface of the solid is then specified via a heat transfer coefficie ...
Temperature
... Hold the beaker in your hands. Explain what you observe. 4. Thermal Expansion of solids - bimetallic strip Heat the strip using the hairdryer or hot air gun. What happens to the strip, and why? Can you think of a use for such a strip? C. Quantitative Questions: 1. Aluminium rivets used in aeroplane ...
... Hold the beaker in your hands. Explain what you observe. 4. Thermal Expansion of solids - bimetallic strip Heat the strip using the hairdryer or hot air gun. What happens to the strip, and why? Can you think of a use for such a strip? C. Quantitative Questions: 1. Aluminium rivets used in aeroplane ...
effects of concentration and solvent composition on the electrical
... volume. The density is decreased with the increase of alcohol content for the ethanol-water mixed solvent system. This behaviour has been found to be similar in the literatures [15, 16, 17]. As a liquid becomes warmer, the molecules spread out more. When the molecules are more spread out, the substa ...
... volume. The density is decreased with the increase of alcohol content for the ethanol-water mixed solvent system. This behaviour has been found to be similar in the literatures [15, 16, 17]. As a liquid becomes warmer, the molecules spread out more. When the molecules are more spread out, the substa ...
Simulation of large capacity MSF brine circulation plants
... Vapor condensation results in the increase of the temperature of the brine stream flowing inside the tubes. This is a very important design feature, where most of the thermal energy provided by the heating steam is recovered by the brine stream before entering the brine heater. Non-condensable gases ...
... Vapor condensation results in the increase of the temperature of the brine stream flowing inside the tubes. This is a very important design feature, where most of the thermal energy provided by the heating steam is recovered by the brine stream before entering the brine heater. Non-condensable gases ...
detailed lecture outline
... behave as distinct entities. The presence of a cell membrane and active transport at the membrane surface enable cells to maintain internal environments with a composition that differs from their surroundings. Figure 27-2 The principal ions in the ECF are sodium, chloride, and bicarbonate. The ICF ...
... behave as distinct entities. The presence of a cell membrane and active transport at the membrane surface enable cells to maintain internal environments with a composition that differs from their surroundings. Figure 27-2 The principal ions in the ECF are sodium, chloride, and bicarbonate. The ICF ...
Laboratory Exercises in Physical Chemistry
... In this experiment a thermos bottle is used as a calorimeter. The thermos bottle is closed with a lid. Determination of the calorimeter constant, C: 1) fill the thermos bottle with 300 ml of distilled water, put a stirrer into it and take temperature-time readings at 10-second intervals until the di ...
... In this experiment a thermos bottle is used as a calorimeter. The thermos bottle is closed with a lid. Determination of the calorimeter constant, C: 1) fill the thermos bottle with 300 ml of distilled water, put a stirrer into it and take temperature-time readings at 10-second intervals until the di ...
Countercurrent exchange
Countercurrent exchange is a mechanism occurring in nature and mimicked in industry and engineering, in which there is a crossover of some property, usually heat or some component, between two flowing bodies flowing in opposite directions to each other. The flowing bodies can be liquids, gases, or even solid powders, or any combination of those. For example, in a distillation column, the vapors bubble up through the downward flowing liquid while exchanging both heat and mass.The maximum amount of heat or mass transfer that can be obtained is higher with countercurrent than co-current (parallel) exchange because countercurrent maintains a slowly declining difference or gradient (usually temperature or concentration difference). In cocurrent exchange the initial gradient is higher but falls off quickly, leading to wasted potential. For example, in the diagram at the right, the fluid being heated (exiting top) has a higher exiting temperature than the cooled fluid (exiting bottom) that was used for heating. With cocurrent or parallel exchange the heated and cooled fluids can only approach one another. The result is that countercurrent exchange can achieve a greater amount of heat or mass transfer than parallel under otherwise similar conditions. See: flow arrangement.Countercurrent exchange when set up in a circuit or loop can be used for building up concentrations, heat, or other properties of flowing liquids. Specifically when set up in a loop with a buffering liquid between the incoming and outgoing fluid running in a circuit, and with active transport pumps on the outgoing fluid's tubes, the system is called a Countercurrent multiplier, enabling a multiplied effect of many small pumps to gradually build up a large concentration in the buffer liquid.Other countercurrent exchange circuits where the incoming and outgoing fluids touch each other are used for retaining a high concentration of a dissolved substance or for retaining heat, or for allowing the external buildup of the heat or concentration at one point in the system.Countercurrent exchange circuits or loops are found extensively in nature, specifically in biologic systems. In vertebrates, they are called a Rete mirabile, originally the name of an organ in fish gills for absorbing oxygen from the water. It is mimicked in industrial systems. Countercurrent exchange is a key concept in chemical engineering thermodynamics and manufacturing processes, for example in extracting sucrose from sugar beet roots.Countercurrent multiplication is a similar but different concept where liquid moves in a loop followed by a long length of movement in opposite directions with an intermediate zone. The tube leading to the loop passively building up a gradient of heat (or cooling) or solvent concentration while the returning tube has a constant small pumping action all along it, so that a gradual intensification of the heat or concentration is created towards the loop. Countercurrent multiplication has been found in the kidneys as well as in many other biological organs.