1. Environmental Engineering is the integration of science andengineering principles to improve the natural environment, to provide healthy water, air, and land for human habitation and for other organisms, and to clean up pollution sites.

2.Branch of science concerned with the practical applications of fluids, primarily liquids, in motion. It is related to fluid mechanics, which in large part provides its theoretical foundation. Hydraulics deals with such matters as the flow of liquids in pipes, rivers, and channels and their confinement by dams and tanks. Some of its principles apply also to gases, usually when variations in density are relatively small. The scope of hydraulics extends to such mechanical devices as actuators and control systems. Bernoulli's principle, Pascal's law, pump.

3 Fluids includes gasses as well as liquids. Fluid mechanics will include both static and dynamic fluids of all types. Hydraulics involves only static and dynamic liquids, most commonly water , solutions and o Hydraulic Machine

Definition of Hydraulic MachineThe machine in which force is transmitted by liquids under pressure is known as hydraulic machine. Example: Hydraulic Brakes, Hydraulic Jack  1. (General Physics) the pressure exerted by the atmosphere at the earth's surface. It has an average value of 1 atmosphere

Collins English Dictionary – Complete and Unabridged © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003

Difference between gauge and absolute pressureDefinition:The absolute pressure pabs is the pressure compared with the zero pressure of empty space (i.e. a vacuum).

The gauge (relative) pressure prel is the pressure compared with atmospheric pressure pamb (surrounding air pressure).

Problem:The atmospheric pressure (in hPa) changes continually, according to the altitude or weather.According to the application, the pressure will need to be measured either as gauge (relative) pressure or a

Difference Between Gauge and Absolute Pressure Measurement

Pressure can be described as the force applied to an area. There are many different systems of pressure measurement, with absolute pressure and sealed gauge pressure

being two of the most common. There are many differences between these two measurements of pressure that have significant effects on their use and measurement.

Depending on why you are measuring pressure, determining whether you need gauge or absolute reference pressure is as important as selecting the pressure range itself,

particularly for low pressure. If you get it wrong it could create huge errors in your measurements.

The simplest way to explain the difference between the two is that absolute pressure uses absolute zero as its zero point, while gauge pressure uses atmospheric pressure as

its zero point. Due to varying atmospheric pressure, gauge pressure measurement is not precise, while absolute pressure is always definite.

Gauge PressureThe most common pressure reference is gauge pressure which is signified by a ‘g’ after the pressure unit e.g. 30 psig. Gauge pressure is measured in relation ambient

atmospheric pressure. Changes of the atmospheric pressure due to weather conditions

 or altitude directly influence the output of a gauge pressure sensor. A gauge pressure higher than ambient pressure is referred to as positive pressure. If the measured pressure is below atmospheric pressure it is called negative or vacuum gauge pressure.

Gauge pressure sensors only usually have one pressure port. The ambient air pressure is directed through a vent hole or a vent tube to the back of the sensing element. A

vented gauge pressure transmitter allows the outside air pressure to be exposed to the negative side of the pressure sensing diaphragm so that it always measures with

reference to the ambient barometric pressure. Therefore a vented gauge pressure sensor reads zero pressure when the process pressure connection is held open to

atmospheric air.

A sealed gauge reference is very similar except that atmospheric pressure is sealed on the negative side of the diaphragm. This is usually adopted on high pressure

applications such as measuring hydraulic pressures where atmospheric pressure changes will have only a slight effect on the accuracy of the senso. The definition of sealed-

gauge pressure is the pressure measured through a sealed device in which the zero point is set. This set point is whatever the pressure inside of the device was before sealing,

which the manufacturer of the sealed pressure gauge decides.

Absolute PressureThe definition of absolute pressure is the pressure of having no matter inside a space, or a perfect vacuum. Measurements taken in absolute pressure use this absolute zero as

their reference point. The best example of an absolute referenced pressure is the measurement of barometric pressure. In order to produce an absolute pressure sensor the

manufacturer will seal a high vacuum behind the sensing diaphragm. Therefore if you hold open the process pressure connection of an absolute pressure transmitter to the air it

will read the actual barometric pressure.

So how do you know when to measure absolute pressure or when to measure gauge pressure?

This is not always straightforward but generally if you want to measure or control a pressure that is influenced by changes in atmospheric pressure, like the level of liquid in an

open tank for example; you would choose vented gauge pressure as you are interested in the pressure reading minus the atmospheric pressure component.

If you want to measure pressures that are not influenced by changes in atmospheric pressure, e.g. leak testing a completely sealed non-flexible container, you would use an

absolute pressure sensor. If a gauge pressure sensor was used instead to measure the container pressure, and the barometric pressure changed, then the sensor’s reading

would change, despite the fact that the pressure in the container remains the same.

efinitionsfrom The American Heritage® Dictionary of the English Language, 4th Edition

n. The branch of mechanics that studies the motion of a body or a system of bodies without consideration given to its mass or the forces

acting on it.from Wiktionary, Creative Commons Attribution/Share-Alike License

n. The branch of mechanics concerned with objects in motion, but not with the forces involved.

from the GNU version of the Collaborative International Dictionary of English

n. The science which treats of motions considered in themselves, or apart from their causes; the comparison and relation of motions.

from The Century Dictionary and Cyclopedia

n. That part of the science of mechanics which treats of motion, its direction, velocity, acceleration, composition, etc., without reference to

mass or to constraints: opposed to dynamics.

n. The theory of mechanical contrivances for converting one kind of motion into another, as for example for making a piston-rod with a

reciprocating motion communicate to a wheel a uniform rotation. Also called applied kinematics.from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

n. the branch of mechanics concerned with motion without reference to force or mass

EtymologiesFrom Greek kīnēma, kīnēmat-, motion, from kīnein, to move; see kei-2 in Indo-European roots.

(American Heritage® Dictionary of the English Language, Fourth Edition)

From Ancient Greek κίνημα (kínēma, "motion") + -ics. (Wiktionary)

Examples

They then made complex comparisons of the characteristics of movement, known as kinematics, between dogs with different limbs missing and also with

the 'normal' movement of four-legged dogs.

The Earth Times Online Newspaper

They then made complex comparisons of the characteristics of movement, known as kinematics, between dogs with different limbs missing and also with

the "normal" movement of four-legged dogs.

Daily News & Analysis

56 ALBERT EINSTEIN logical reconciliation by making a change in kinematics, that is to say, in the doctrine of the physical laws of space and time.

Out Of My Later Years

But even less recognized is the theoretical system of machine design notation known as "kinematics" that paved the way for complex machines.

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This car's kinematics are more unsorted than my sock drawer.

A Nissan at CrossPurposes With Competence

This issue was recently addressed by David Viano and colleagues, who work at ProBiomechanics LLC, a Michigan firm specializing in occupant kinematics

and injury causation, published last month in Traffic Injury Prevention.

Dr. Sharma’s Obesity Notes » Blog Archive » Weighing in on In-Car Traffic Injuries

Mr. Dennis sees McLaren as "technology flying doctor" service, offering bespoke solutions to companies with urgent problems in complex areas such as

electronics, pneumatics, fluid dynamics, kinematics and material sciences.

McLaren's New Formula

"The researchers point out that the computer evolves these laws without any prior knowledge of physics, kinematics or geometry."

Crunching Out Natural Laws?

Yellowstone hotspot and mantle plume: Seismic and GPS imaging, kinematics, and mantle flow, J. Volcanol.

Scientific Articles on Yellowstone

If you thought Hipparcos satellite which was also ESA of 1991 was good, this one will provide the dynamical knowledge of our part of the Milky Way, and

the information of the kinematics of the whole galaxy!

Obama to Unveil "Ambitous" Plan for NASA | Universe Today

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1. mechanics reverse dictionary (11)Words that contain this word in their definition 

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2. cinematics

3. kinematic

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5. gram

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Word visualization 

Definition of HYDROSTATIC

:  of or relating to fluids at rest or to the pressures they exert or transmit — compare HYDROKINETIC

Uniform and Non-uniform Flows

Uniform Flow

The flow is defined as uniform flow when in the flow field the velocity and other hydrodynamic parameters do not change from point to point at any instant of time.

For a uniform flow, the velocity is a function of time only, which can be expressed in Eulerian description as

         Implication:

1. For a uniform flow, there will be no spatial distribution of hydrodynamic and other parameters.

2. Any hydrodynamic parameter will have a unique value in the entire field, irrespective of whether it 

             changes with time − unsteady uniform flow   OR

             does not change with time − steady uniform flow.

3. Thus ,steadiness of flow and uniformity of flow does not necessarily go together.

 

 Non-Uniform Flow

           When the velocity and other hydrodynamic parameters changes from one point to another the flow is defined as non-uniform.

           Important points:

           1. For a non-uniform flow, the changes with position may be found either in the direction of flow or in directions perpendicular to it.

           2.Non-uniformity in a direction perpendicular to the flow is always encountered near solid boundaries past which the fluid flows.

Reason: All fluids possess viscosity which reduces the relative velocity (of the fluid w.r.t. to the wall) to zero at a solid boundary. This is known as no-slip condition.

Four possible combinations

Type Example1. Steady Uniform flow

Flow at constant rate through a duct of uniform cross-section (The region close to the walls of the duct is disregarded)

2. Steady non-uniform flow Flow at constant rate through a duct of non-uniform cross-section (tapering pipe)

3. Unsteady Uniform flow Flow at varying rates through a long straight pipe of uniform cross-section. (Again the region close to the walls is ignored.)

4. Unsteady non-uniform flow Flow at varying rates through a duct of non-uniform cross-section.

Full Definition of STEADY FLOW

:  a flow in which the velocity of the fluid at a particular fixed point does not change with time —called also stationary flow— compare UNIFORM FLOW

Uniform flow

A truly uniform flow is one in which the velocity is same at a given instant at every point in the fluid.

This definition holds for the ideal case. Whereas in real fluids velocity varies across the section.

But when the size and shape of cross section are constant along the length of channels under consideration, the flow is said to be uniform.

Non-uniform flow

A non-uniform flow is one in which velocity is not constant at a given instant.STEADY FLOW Steady flow is defined as the type of flow in which fluid characteristics like velocity,pressure,density...etc at a point do not change in time. 

UNSTEADY FLOW it is defined as the type of flow in which fluid characteristics like velocity,pressure,density...etc at a point changes with time.