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An I/P transducer is a device that converts an electrical signal into a pneumatic signal for use with pneumatic equipment or valve actuators. You’ll find these devices used in industrial settings. A manufacturing production line that uses liquids, pneumatics or a cooling system during its manufacturing process will have an IP transducer used with other equipment to control the opening and closing of flow valves.
The bearing pressure of a soil is the maximum load that it can bear before its fails by shearing or liquefaction. This value is the primary consideration in the design of foundations. The standard penetration test is a simple method for estimating the mechanical properties of a soil at a potential construction site. Geotechnical engineers have accumulated data over several decades to provide a very empirical relation between SPT results and a soil’s bearing pressure.
Carbon is an essential chemical element for the maintenance of life on Earth. All known life forms are based on organic carbon compounds. The human body is composed of over 18 percent carbon, more than any element besides oxygen. If aliens exist, they may also be carbon-based, as the element is the fourth most abundant in the universe.
If you've ever seen mud flying off of a spinning tire or used a salad spinner, you've seen centrifugal force at work. Centrifugal means to fly away from the center and this rotational force (imagine gravity turned on its side) has been adapted for uses in many fields of science and industry.
A rapid sand filter typically employs three or more layers containing different types of filter materials, which helps filter out multiple types of contaminants. This type of filter is "rapid" because water can flow through it up to 40 times faster than through a slow sand filter. The larger velocity results in larger head loss as well -- head loss measures the decrease in pressure as water flows through a system. You must take head loss into account when designing the filter bed for a rapid sand filter.
Many industries constantly measure the fluid flow of various liquids. It can make a major difference in the profit/loss reports. The flow rate is determined by the liquid's velocity. That, in turn, depends on the pressure differential that forces the liquid through a pipe and the diameter of the pipe itself. The viscosity, drag, friction and density are all factors that exert an influence on the flow rate.
A nib pen is dipped into an inkwell and used to write in calligraphy or to draw pen-and-ink drawings. You can add a reservoir to the nib so you don't need to dip the pen as often. The reservoir will hold a portion of ink at the ready as you draw or write. The problem with using a reservoir is the pen's tendency to drop too much ink when it touches the paper.
From Sherlock Holmes to J.R.R. Tolkien to college professors the world over, pipe smoking is a past time associated with learned men. The pipe itself is considered by pipe smokers to be a thing of beauty, on par with an expensive watch or fountain pen. There are good pipes and bad pipes on the market. Knowing what to look for is key to selecting a proper tobacco pipe. The characteristics of a good wooden pipe are solid construction, pleasing aesthetics and fair price.
In a world full of cheap, throwaway ballpoints, many people still choose to use a fountain pen. Dating back to the 10th century, the design of a fountain pen allows the user to write with far less pressure than a ballpoint or pencil, affording greater comfort. The key component of every fountain pen is its nib. Should it become uneven, the pen may be difficult to use. Even a tiny misalignment of the tines of the nib, not noticeable to the naked eye, can still have a dramatic effect on the pen.
Pneumatic transport is a very common method of moving solid bulk materials from one location to another. The gas velocity in a pneumatic transport system is a critical design component since certain bulk materials have different requirements for suspension. The required flow rate is considered in gas conveying as it relates to the velocity and the conveying pipeline size. Minimum flow rate and velocity values are based on the density of the material to be transported and the pipeline size must be adequate to support the minimum rates.
The standard scientific unit for pressure is the Pascal. One Pascal is the pressure when a force of one Newton acts of a square meter of area. Psia, pounds per square inch, also describes a magnitude of force acting on a specific area. The "a" in the unit stands for "absolute," which means it takes into account atmospheric pressure. This distinguishes it from psig, gauge pressure, which excludes this background pressure.
SCFM stands for standard cubic feet per minute and is a standard volumetric flow rate used in sizing compressible fluid pipelines such as in compressor air systems. For all gas systems, the velocity of the flow and the flow rate are related to the pipeline's internal diameter. If two of the three variables are known, then the third variable is easily calculated.
Pneumatic transport refers to a system to convey bulk solid materials using gas as the conveying medium. Air is commonly used as the conveying gas but other options may be used with reactive or explosive materials. For any given material, there is a minimum volumetric flow rate to transport the material and keep it in suspension. This volumetric flow rate depends on the velocity of the air as well as the pipe size.
A vapor is different from a gas in that it can be condensed to a liquid or solid with an increase in pressure while maintaining the same temperature. Industrial processes often employ the use of vapors such as distillation and gas chromatography. The velocity of these vapors in a pipeline is important to the efficiency, especially if a goal of vapor phase reactions is to condense the vapor back to a liquid. If the velocity is too fast or too slow, condensation may not be efficient. Velocity is calculated in units of feet per second.
Velocity is the speed of a material that can be measured in units such as feet per second. It is how many feet a volume of gas travels in one second. Recommended velocities of gases such as air are typically 90-120 feet per second. The calculation of velocity in a pipeline requires the volumetric flow rate and the pipe's internal diameter.
The space shuttle mainly uses liquid oxygen and liquid hydrogen for fuel. These ingredients are stored in large tanks of more than 850,000 gallons in size on the shuttle launch pad. When the shuttle arrives on the launch pad, the liquids are pumped into the craft and allow it to take off. Liquid hydrogen, although formed from an extremely common element, is not naturally found on Earth. Instead, it produced industrially. The process is extremely complex and requires high-tech equipment.
A blowtorch uses a gas-fed flame for heating the work piece to create a weld. The fuel used in a blowtorch can be either straight gas or a mixture of fuel gas and oxygen. The fuel gases used include acetylene, propane and hydrogen. A blowtorch controls the ratio of fuel gas and oxygen in order to control the flame and its temperature. Welding can be difficult and potentially dangerous, which is why many potential welders enroll in a course to gain certification and training before starting welding projects on their own.
Thermal mass is a measure of how a material absorbs heat. Thermal mass is a specification used most commonly in building construction as an indicator of how easily the temperature of an area is protected from fluctuations by the mass of the materials around the area. Materials with a large thermal mass act as "thermal cushions" that accept or give off heat from an outside environment without requiring a large transfer of heat into or out of a contained environment.
You may well find the total flow rate of water through a pipe a more useful measure than the water's velocity. The volumetric flow rate, measured in gallons per minute, describes the actual quantity of water. It describes the pipe's output, and this value also helps you calculate the water's pressure. The velocity, on the other hand, just states the speed at which the water travels, which reveals little about the pipe's operation.
Quartzite is the rock form of the mineral quartz. It is a hard stone, registering 6.5 to 7 on the Mohs scale. Other attributes that make it a good stone for crafting projects are its density, strength, weather resistance and low porosity. The stone was first used by primitive humans during the Lower Paleolithic period. It has been a stone of choice in many human industries and arts ever since.
Air and other gases are typically measured for volumetric flow rate in cubic feet per minute (cfm), and the volumetric flow of air depends on the temperature and pressure of the system. Air is sometimes considered as an ideal gas which has very predictable physical properties. Temperature, volume and pressure are all interdependent and the system operating conditions are paramount to determining the volumetric flow rate. Converting a volume of air to a pipeline velocity such as feet per minute (fpm) requires the internal diameter of the pipeline. This converts a standard volumetric flow rate of cubic feet per minute…
Air exapnds when it is heated, and it condenses when it is cooled. It rises and sinks, and its motion creates and dissipates storms. The thermodynamic properties of air are the primary reasons air moves, and when air moves in a specific manner, turbulence occurs. Geography, friction and weather patterns all affect the potential for turbulence.
Quartzite is a metamorphic rock that is created when quartz sandstone undergoes metamorphism. Metamorphism involves extreme heat and pressure, which causes quartz grains to compact and weave tightly together creating dense quartzite. Its density makes quartzite mostly resistant to erosion and volatile weather. Quartzite has a myriad of uses from ground rock in road work to glassy decorative beads.
When calculating the velocity of a gas or liquid through an object, scientists use a simple equation in which the volumetric flow rate is divided by the cross-sectional flow area. In some instances, however, the object that the gas or liquid moves through has some obstructions in it, which makes it more difficult to calculate the actual velocity. In these instances, a superficial velocity is often calculated in which the velocity is measure as if the the obstruction were not there.
A propane torch can be a convenient and useful tool for welding, but it is also a very dangerous tool if damaged or used incorrectly. Propane gas is a highly volatile compound that requires caution by the user. Knowledge of the dangers of using propane gas and a propane gas torch can help you to avoid accidents.
Pressure-reducing valves are typically installed in residences, hospitals and schools where it is important to control water pressure and hence the amount of vibration, and noise, produced by water pipes.
Although black iron pipe has iron in its name, it's actually made of low-grade, mild steel. Mild steel is a soft steel that can be easily welded and cut with a torch. Dealers and industry professionals in America will simply refer to schedule 40 steel pipes when talking about black iron pipe. Mild steel is used because it can bend; it can be cut with a torch and is much easier to work with overall. Knowing what black iron is made of is important because the iron's thermal properties are different from those of mild steel.
Most steel cutting used to be done with an oxyacetelene torch. Today, cutting is also done with plasma cutters which are similar to a cutting torch. Whether gas or plasma, if you need to cut a straight line or any precise line, you're probably going to need a guide of some kind. There are several available.
Air, or pneumatic, motors use compressed air to produce continuous rotary motion. They are typically much less efficient than electric motors, but, being of equal size, they are more powerful than electric motors.
Hydraulic pumps move fluids. To do so efficiently, they must have sufficient power to keep the motor running at peak flow. The power requirements are affected by the speed at which the pump must operate, the volume of fluid that must be pumped and the pressure that develops in the pipes or hoses through which the fluid is pumped. Over the useful lifetime of a hydraulic pump, the cost of fuel to run it will vastly exceed the equipment cost, so you want a pump that will provide enough power without using more fuel than necessary to run it efficiently.
Fluid dynamics is concerned with the motion of fluids (such as liquids and gases). One of the most important (and mysterious) concepts is fluid dynamics is turbulent flow, which is flow that becomes chaotic and difficult to predict. Cigarette smoke which begins to curls as it leaves the cigarette is an example of turbulent flow. Generally, objects which surpass a certain velocity will undergo turbulent flow (depending on other fluid properties). Calculating the velocity of a fluid undergoing turbulent flow within a pipe (or similar structure) is possible using this equation: velocity = (Reynolds number x kinematic viscosity) / (diameter…
A centrifugal pump works by converting the energy of a spinning impeller to increase the velocity of a liquid. The impeller is the device that rotates in the liquid and is usually contained inside a volute, or casing. The impeller is typically connected to an electric motor which provides the energy to be transferred to the liquid. The pump must be designed to carry the desired flow rate, using the most efficient and properly sized motor.
Laboratory chemicals often require storage in locations that keep them isolated from the laboratory environment. The chemicals may also give off fumes that are noxious or dangerous. When these chemicals are used or stored, they must remain in a fume hood. An important specification for a fume hood is its capture velocity. Fume hood capture velocity is the speed at which fumes must be moving at a specific distance in front of the hood opening in order for the fumes to move to the hood and exhaust out of the room. This ensures that no other air currents in the…
Fire hoses use tremendous pressure to shoot out jets of water at high speeds. The amount of water the hose shoots out in a given time is called its flow rate. Fire hoses of different diameter can have varying flow rates and the rates can change quickly as the pressure of the water increases or decreases. Firefighters need to know the flow rate of hoses to determine how effective they will be in fighting fires of different magnitudes.
The purpose of a compressed air dryer is to remove water vapor from compressed air. This, in turn, lowers the temperature to which the air can be cooled before water vapor condenses into liquid water and protects pneumatic components from corrosion.
Valves are used to start, stop and regulate the flow of liquid in a variety of domestic, commercial and industrial applications. Valve selection requires knowledge of the characteristics of the valve and the liquid being regulated.
Centrifugal pumps are the most common type of pump used in water treatment facilities. They convert energy of an electric motor or turbine into kinetic energy, via a rotating part (impeller), and then into pressure energy via a stationary part (diffuser).
Propane torches are categorized as air-fuel torches because they use a mixture of propane gas and oxygen. This mixture, when lit, produces a clean-burning flame suitable for heating or welding purposes. If you do not weld often or are concerned with the environmental impact of your practice, propane torches can serve you well as they are inexpensive, clean-burning and recyclable.
A hydraulic ram uses the power of gravity to direct stream flow to an elevation significantly above the level of the stream itself. A ram consists of several chambers designed to force water uphill by collecting the downward flow and putting it under air pressure. The result is a constant lifting of the water to a collection tank, a process that requires no power source other than the kinetic energy of the moving stream.
Water flowing downhill carries kinetic energy that can be used to pump water to an elevation higher than the collection point. This is accomplished by capturing the power of the moving stream through the operation of a hydraulic ram pump, a specialized instrument that collects the water flow, compresses it with air and forces it uphill. Water falling no more than five feet can be delivered through a ram to an elevation more than 20 feet above the stream level. No electricity or other outside power source is required; the water actually pumps itself.
Most water pumps work by spinning an impeller through water, which generates momentum and then suction. However, if even a small amount of air is pulled into the chamber that houses the impeller, it cannot properly impart momentum, and the pump stops.
You can deadhead a centrifugal pump if you operate it full of liquid with the inlet and outlet valves closed, so there is no flow through the pump. In this case, the rotating component of the pump (impeller) will continue to agitate the same volume of liquid.
A centrifugal pump consists of rotating component, known as an impeller, and a stationary component, known as a volute or diffuser. The impeller converts energy from an electric motor or turbine into kinetic energy; the volute or diffuser converts the kinetic energy into pressure energy, or head.
Pressure drop (over a given length of pipe) and pipe size (inside diameter) are only two of the variables that need to be known to calculate the flow in a pipe. The third is the friction factor. The friction factor is usually found from a Moody resistance diagram. However using the diagram requires knowing the Reynolds number of the flow which takes knowing the kinematic viscosity and velocity, and the roughness of the pipe interior. The way out of this dilemma is to assume the flow is in the turbulent linear portion of the Moody diagram.
Firefighters, rescue workers and others who enter an area with an atmosphere that endangers life and health need a self-contained breathing apparatus (SBCA) to protect them from gases, smoke, sprays and vapors. Manufacturers must test SCBAs before selling them, and safety officers must test and maintain them regularly to ensure they operate correctly. SBCAs that don't meet test bench requirements should be repaired or discarded immediately.
Fume hoods are a type of ventilation device often used in laboratories to limit scientists' exposure to harmful fumes or vapors. While nearly all fume hoods undergo factory testing before installation, when dealing with potentially poisonous gases, it's always a smart idea to periodically test fume hoods to make sure they are still functioning properly.
Pumps are essential to hydraulic systems -- systems operated by water or other liquids in motion -- because they convert mechanical energy into pressure energy, or head. The pressure applied to the liquid causes it to flow at the required rate.
Air -- which is a mixture of nitrogen, oxygen and other gases -- is stable under normal conditions and nonflammable, so it is not, in itself, considered a dangerous substance. However, compressed air cylinders are typically heavy, highly pressurized metal containers, so they need to be handled with care.
Hoses typically consist of an inner rubber tube, reinforcement of some kind and an outer rubber cover, all stuck together with adhesive. If you mention a hose, most people naturally think of a garden hose. However, water-carrying hoses are used in all manner of applications, including in automobiles, industry and even computers.
Modern aircraft have hundreds of hydraulic pipes, lines and other components that actuate movable surfaces. The hydraulic fluid that fills this plumbing is a hazardous material and must be kept pressurized, so proper pipe identification is crucial to aircraft safety.
The British thermal unit (Btu) is an energy measurement unit typically used to describe the energy content of fuels. More specifically, it is the amount of heat required to raise the temperature of 1 lb. of liquid water by 1 degree Fahrenheit when the liquid is at its maximum density (which occurs at about 39 degrees Fahrenheit).
All hydraulic systems use pressure to move components, including automotive brake systems. Pump types vary, so it can be difficult to identify and locate hydraulic pumps if you are unfamiliar with a particular hydraulic system or unfamiliar with hydraulics, in general. But there are a few basic similarities between all hydraulic pumps.
The J75 is a high-thrust turbojet engine commissioned by the United States Air Force in 1955 for use in fighter jets. This turbojet engine was designed by Pratt and Whitney, an engine manufacturing company founded in 1925 by Frederick Brant Rentschler, who had previously supervised aircraft engine production for the U.S. Army during World War I. The J75 turbojet engine remained in production from 1956 to 1967, outfitting fighter jets and, later, commercial aircraft.
A centrifugal pump is a simple type of pump used to impart kinetic energy to a fluid. These pumps require that power be supplied to rotate an impeller to move fluid.
Signet manufactures flow meters to analyze and monitor the rate of water flow through a system. When setting up digital flow monitors you need to input flow factors based on your system's valves, pipe material and pipe diameter. There is not room in this article to provide more than a general overview of these factors, but reference books and flow sensor manuals give in-depth detail regarding flow factor settings.
Earl Scott founded Scott Health and Safety in 1932. At that time the company was called Uniloy Accessories Corporation and it provided the first pivoting tailwheel for airplanes. Scott has grown since that time and it now provides health and safety products, such as supplied air, respirators and compressors. As of 2010, it was making three types of SCBA cylinders: aluminum, carbon and ST7 Tough.
Gas welding is an effective way to attach two pieces of metal together, but it is not an art for the careless. Without caution, you can end up with a serious injury. Gas welding uses highly flammable substances to bond two pieces of metal. Careless handling of the gas-welding torch can result in severe burns and other serious injuries. With the proper knowledge and skill, though, welding is a moderately safe and simple process.
A pump diffuser is part of a centrifugal pump designed to make the pump more efficient by optimizing the flow of the liquid being pumped. This makes the flow more controlled and increases the liquid pressure, increasing the effect of the centrifugal pump's motion.
While not as efficient as comparable electric motors, hydraulic motors are far superior for many applications. The hydraulic motor is a simple kinetic transfer device, taking motion from the power-generation pump and transmitting it to the hydraulic motor without any energy conversion. This means that the hydraulic motor can generate an enormous amount of power for its size, and a pressurized gas reservoir or spring-pressure piston can quickly pressurize the pump for a massive and instantaneous boost in power that no battery or capacitor can match.
The setup for oxyacetylene welding is less complicated than metal inert gas (MIG) or tungsten inert gas welding (TIG) because it does not require a computer control or electronic welding torch. However, oxyacetylene welding still has complications that arise and if unresolved could impact the quality of your weld or even pose a safety hazard. You can create more successful and professional looking oxyacetylene welds by following these practices.
A siphon is used to transfer liquid from a higher elevation to a lower elevation. This simple pump consists of a pipe or tube that extends upward from liquid in one container and then bends downward into a second container that sits at a lower level than the first one. Siphons can be used for a variety of tasks, from emptying a gasoline tank to filling a lake.
Hydraulic systems function using air or water pressure. By transferring and focusing force through this pressure, the user can move objects that are heavier than he could move on his own, that are far away or both. Hydraulic systems are present in a wide variety of contexts, from farms to automobile brakes to simple things such as syringes. The underlying theme, though, of transferred force through pressure, is the same.
The primary function of an air or pneumatic cylinder is to utilize compressed air and air pressure to move things. An air cylinder converts the energy of the compressed air into motion. The two types of air cylinders, single-acting or double-acting, have slight variations in their internal parts, function and design. However, all air cylinders have a cylinder body, a piston, packing glands, packing and a piston rod and head for internal parts. Some cylinders may also have a spring and cushion assembly.
A centrifugal pump is a basic pump that is used to move liquid from one place to another. It is excellent for high-volume situations, but it is not particularly efficient. This means that water pumping forward always has some water flowing backward at the same time, thus detracting from the total output.
Hydrogen is a stable gas comprising two hydrogen molecules. At 0 degrees Celsius and one atmosphere of pressure---otherwise known as standard temperature and pressure---hydrogen is a colorless, odorless, tasteless, nonmetallic but highly combustible gas. Hydrogen is the most abundant element in the universe, comprising about 75 percent of its known mass.
The flow rate is the speed with which a liquid goes through a pipe; the pressure is the amount of liquid in relation to the pipe's size. This means that both of these affect one another--high pressure creates a high flow rate, and a high flow rate creates high pressure. Changing your flow rate and pressure can be either easy or difficult, depending on the way your pipes work. Generally, though, it is easy, as pipes often come with valves designed to adjust both of these things.
Whether you own a motorcycle to zoom through the busy city streets or to cruise the quiet back roads, you want your bike to work the way it was designed to. A clean fuel injector is a necessity for a motorcycle to run smoothly and to preserve its lifespan. Cleaning a motorcycle injector is considered basic maintenance and is moderately easy for any bike enthusiast to do in her own driveway.
Pressure flow characteristics of a fluid flowing through a pipe include several components. A fluid at a certain temperature and pressure traveling through a straight pipe will lose pressure (pressure drop) due to friction between the fluid and the pipe wall. If there are bends, fittings (valves, instruments, for example) or rough pipe, that pressure drop will increase and can be measured and predicted.
Jatropha is a tropical plant whose seeds contain a large amount of oil. This oil, while inedible, may be used as a fuel for lighting, cooking and heating. It may also be processed into biodiesel to power diesel engines for transportation, farming, industry and electricity generation. The primary advantages of jatropha over other oil-producing plants are that it is tolerant of poor soil, and in fact improves it by fixing nitrogen in the soil. A manual or engine-powered press can be used to extract the oil from the seeds.
When your kidneys filter your blood to remove waste products, they initially pass the blood through a membrane that removes large molecules like proteins but permits waste products, salts, water molecules, amino acids and sugars like glucose to pass through. In order to ensure that valuable molecules like glucose and amino acids aren't excreted together with the waste products, the kidney must reabsorb them, a process that takes place in the proximal tubule.
Centrifugal pumps are vital to the operation of most processing plants. It converts energy from a motor into pressure energy in order to pump fluid. When centrifugal pumps break down, the operation of the plant may come to a halt. In order to properly troubleshoot non-working pumps, engineers must understand the physics behind the proper operation of the pump.
Quartzite is a hard, metamorphic rock composed mostly of sandstone. The sandstone is converted to quartzite through heating and pressure that is usually caused by tectonic compression. Since this metamorphism has no specific tectonic association, quartzite can form just about anywhere that sandstone exists. Quartzite has certain defining characteristics.
Reverse osmosis is a process for removing salt and other dissolved solids (contaminates) from water. The process involves a semi-permeable membrane that only lets relatively pure water pass through. On one side of this membrane is the unprocessed water. Pressure applied to the unprocessed water makes it flow through the membrane. The membrane traps contaminants, and purified drinking water flows out of the membrane. A more technical description of reverse osmosis first requires an understanding of osmosis.
A hydraulic motor is a type of motor that converts the flow of a liquid under pressure into rotational motion. In essence, a hydraulic motor is simply a hydraulic pump working backward: Instead of mechanical parts moving fluid by pushing on it, high-pressure fluid pushes on the mechanical parts, causing them to move. Broadly speaking, there are three kinds of hydraulic motor: gear, vane and piston.
Jet engines power most modern aircraft. When you look into a jet engine, you can see the blades of the compressor face, but the engine actually starts at the inlet. The first part of a jet engine is the diffuser, which most people call the inlet. This part of the engine increases the pressure in the airflow by expanding it. As air expands from a smaller cross-sectional area at the beginning of the diffuser to a larger cross-sectional area at the compressor face, the flow velocity decreases. This decrease in velocity causes an increase in pressure.
Gas welding is a welding process that uses a torch with a gas-fed flame to heat the work piece to create a weld. The fuel is either a straight gas or a mixture of fuel gas and oxygen. A variety of fuel gases can be used, including acetylene, propane or even hydrogen. Gas welding uses a torch that controls the ratio of fuel gas and oxygen, either from the atmosphere or from a second fuel tank, to control the flame and its temperature.
Automobiles are complex machines that use many different phenomena defined in the study of physics to move people from place to place. The operation of a car can be broken down into dozens or hundreds of physics processes.
Fountain pens often are associated with the academic and professional world. A person must have great care and concern for the condition of his writing utensils to own a fountain pen. These delicate instruments are meant to be refilled and can last a lifetime with proper care and maintenance. The nibs, or tips, of these pens are particularly susceptible to damage; if the nib is not working correctly, ink flow can be ruined. With some care and precision, you can make basic repairs to the nib of your fountain pen.
Many people take aircraft for granted. The plane simply flies, simple as that. However, when you peel back the aircraft's metal skin, you find a complex network of systems, including hydraulics and pneumatics.
Beer taps installed in a home bar or on a keg usually function properly but can have problems from time to time. To fix a problem with your beer tap, it is important to determine what type of problem is occurring. Beer that comes out too slowly or drains from the lines when pouring a glass can indicate a problem with the line.
The term water currents means sections of water moving in a single direction. The only force necessary to create a water current is a force that moves the water down a gradient. A difference in the level of something, be it gravity, pressure or temperature, causes a gradient. This difference between two areas facilitates the flow of water, creating a current. All currents develop in the direction of the steepest gradient possible. This phenomenon accounts for the fact that water always moves where it's easiest to move.
Compressed gases are gases that have compacted down into a smaller space than they usually inhabit. This causes the molecules of the gas to move close together, vibrating and bouncing off each other more quickly and creating more energy. People use this stored energy for a variety of tasks, from moving heat to move large pieces of machinery.
Ground effects is an aerodynamic phenomenon that happens when aircraft are flying close to the ground. The effect is quite noticeable in many aircraft and is a fun experience for beginning pilots. Experienced pilots must be aware of how ground effects will change the flying characteristics of their aircraft and be ready to use or counteract ground effects when they occur.
Condensing units are familiar temperature-control devices in refrigerators, air conditioners, heat pumps and chillers. They move energy in the form of heat by compressing a gas known as a "refrigerant," then pumping it through a system of coils and using the air around the coils to heat and cool spaces. Electronic controls, fans, pumps and coils manage the condenser's work.
People working with hazardous chemicals use a fume hood. A fume hood is a partially enclosed workspace where lower pressure inside keeps fumes away from people. An exhaust fan and filter safely remove and treat the air inside the hood.
Hydraulic motors use a fluid--usually oil--to create motion. Hydraulic fluid is first pumped from a reservoir into pressurized tubes by a hydraulic pump, which is driven by an internal combustion engine. Those tubes take the fluid to the hydraulic motor or motors. The pressure turns the motors by flowing through them, then flows back into the reservoir where the whole process begins again.
Hydraulic motors are driven by hydraulic pumps, which provide pressurized oil to create motion. Usually, the pump is driven by a gas or diesel engine. The simplest hydraulic pump is the gear pump. Two meshed gears rotate in a box, pushing oil in front of them. The oil is pushed from an inlet valve into an outlet valve. There are also pumps that use rotating screws or turning vanes to push oil. The oil then flows through tubes into the hydraulic motors, and back into the pump.
The first component of a jet engine is a diffuser. This is the space between the mouth of the engine and the first set of blades on the compressor. The cross-sectional area increases as the space gets close to the compressor, so the velocity of the flow is decreased and the pressure is increased. This aids the compressor and begins the process of adding energy to the flow.
