A hydraulic device is a device that uses liquids to transmit pressure equally from one point to another.

Hydraulic machines are machinery and tools that use liquid fluid power to do simple work. Heavy equipment is a common example.
In this type of machine, hydraulic fluid is transmitted throughout the machine to various hydraulic motors and hydraulic cylinders and becomes pressurised according to the resistance present. The fluid is controlled directly or automatically by control valves and distributed through hoses and tubes.

NOTE: Hydraulic machinery is operated by the use of hydraulics, where a liquid is the powering medium.

It is important that a hydraulic system contains no air bubbles. You may have heard about the need to “bleed the air out of the brake lines” of you car. If there is an air bubble in the system, then the force applied to the first piston gets used compressing the air in the bubble rather than moving the second piston, which has a big effect on the efficiency of the system.

Some examples of hydraulic devices include:
Jaws of life,
Metal shears,
Car crushers,
Automobile brakes,
Garbage compactors,
Log splitters,
Zero radius lawn tractors,
Bobcat tractors.

The Penalty for Ignorance is Lack


A gear or cogwheel is a rotating machine part having cut teeth, or cogs , which mesh with another toothed part to transmit torque , in most cases with teeth on the one gear being of identical shape, and often also with that shape on the other gear.
Nearly all mechanical devices rely on some form of gearing, and the key to a reliable gear is a good and appropriate design taking into account such factors as strength, wear resistance, noise, and fatigue resistance.


               Meshing Gears

Two or more gears working in a sequence (train) are called a gear train or, in many cases, a transmission ; such gear arrangements can produce a
mechanical advantage through a gear ratio and thus may be considered a
simple machine. Geared devices can change the speed, torque, and direction of a power source. The most common situation is for a gear to mesh with another gear; however, a gear can also mesh with a non-rotating toothed part, called a rack, thereby producing
translation instead of rotation.

1-Bevel gear:
These gears have teeth cut on a cone instead of a cylinder blank. They are used in pairs to transmit rotary motion and torque where the bevel gear shafts are at right angles (90 degree) to each other.
2-Crossed helical gear
These gears also transmit rotary motion and torque through a right angle. The teeth of a helical gear are inclined at an angle to the axis of rotation of the gear.
3-Worm and worm wheel
A gear which has one tooth is called worm. The tooth is in the form of a screw thread. A worm wheel meshes with the worm. The worm wheel is a helical gear with teeth inclined to that they can engage with the tread like worm. Like the cross helical gears, the worm and the worm wheel transmit torque and rotary motion through a right angle. The worm always drives the worm wheel and never the other way round. The mechanism locks if the worm wheel tries to drive the worm. Worm mechanism is very quiet running.
4-Helical gear
The gear is used for application that requires very quite and smooth running, at high rotational velocities. Parallel helical gears have their teeth inclined at a small angle to their axis of rotation. Each tooth is part of a spiral or helix. The helical gears have splines cut in their center holes. The gear can move along a splined shaft, although they rotate with the shaft. Double helical gears give an efficient transfer of torque and smooth motion at very high rotational velocities.
5-Spiral bevel gears
When it is necessary to transmit quietly and smoothly a large torque through a right angle at high velocities, spiral bevel gears can be used. Spiral bevel gears have teeth cut in helix spiral form on the surface of a cone. They are quieter running than straight bevel gears and have a longer life. Spiral bevel gears are used in motorcar axle gearboxes.
6-Internal gears
It is possible to cut gear teeth on the face of a gear wheel. Also, gear teeth can be cut the inclined of a gear ring. Internal gears have better load carrying capacity than external spur gear. They are safer in use because the teeth are guarded.
         Reference: Wikipedia , http://www.enggpedia.com.

The Penalty for Ignorance is Lack


INTRODUCTION: Your digestive tract stretches from your mouth to your anus. It includes the organs necessary to digest food and process waste.

The human gastrointestinal tract, or GI tract, or GIT is an organ system responsible for consuming and digesting foodstuffs, absorbing nutrients, and expelling waste.
The tract consists of the stomach and intestines, and is divided into the upper and lower gastrointestinal tracts.

Do you know that The whole digestive tract is about nine metres (30 feet) long?

The GI tract releases hormones from
enzymes to help regulate the digestive process. These hormones, including
gastrin, secretin, cholecystokinin , and
ghrelin, are mediated through either
intracrine or autocrine mechanisms, indicating that the cells releasing these hormones are conserved structures throughout evolution .


Nutrients from the GI tract are not processed on-site; they are taken to the liver to be broken down further, stored, or distributed.

The Penalty for Ignorance is Lack


A career is an individual’s journey through learning, work and other aspects of life. There are
a number of ways to define a career and the term is used in a variety of ways.

Definitions and etymology
Career is defined by the Oxford English Dictionary as a person ‘s “course or progress through life (or a distinct portion of life)”. In this definition career is understood to relate to a range of aspects of an individual’s life, learning and work. Career is also frequently understood to relate to the working
aspects of an individuals life e.g. as in career vwoman . A third way in which the term career is
used to describe an occupation or a profession that usually involves special training or formal
education, and is considered to be a person’s lifework. In this case “a career” is seen as a
sequence of related jobs usually pursued within a single industry or sector e.g. “a career in law” or
“a career in the building trade”. The etymology of the term comes from the French word carriere (“road, racecourse”) which, in turn, comes from the Latin word “(via)
cararia” (track for wheeled vehicles) which originated from the Latin word carrus” which means “wagon”.
By the late 20th century, a wide range of choices (especially in the range of potential professions )
and more widespread education had allowed it to become possible to plan (or design) a career: in
this respect the careers of the career counselor and of the career advisor have grown up. It is also not
uncommon for adults in the late 20th/early 21st centuries to have dual or multiple careers, either
sequentially or concurrently. Thus, professional identities have become hyphenated or hybridized
to reflect this shift in work ethic. Economist Richard Florida notes this trend generally and more
specifically among the ” creative class “.

Career choice
According to Behling and others, an individual’s decision to join a firm may depend on any of the three factors viz. objective factor, subjective factor and critical contact.
Objective factor theory assumes that the applicants are rational. The choice, therefore, is exercised after an objective assessment of the tangible benefits of the job. Factors may include the salary, other benefits, location, opportunities for career advancement, etc.
Subjective factor theory suggests that decisionmaking is dominated by social and psychological factors. The status of the job, reputation of the organization and other similarfactors plays an important role.
Critical contact theory advances the idea that a candidate’s observations while interacting with
the organization plays a vital role in decision making. For example, how the recruiter keeps in
touch with the candidate, the promptness of response and similar factors are important. This
theory is more valid with experienced professionals.

These theories assume that candidates have a free choice of employers and careers. In reality the
scarcity of jobs and strong competition for desirable jobs severely skews the decision making
process. In many markets employees work particular careers simply because they were forced
to accept whatever work was available to them.
Additionally, Ott-Holland and colleagues found that culture can have a major influence on career
choice, depending on the type of culture.
When choosing a career that’s best for you, according to US News, there are multiple things to
consider. Some of those include: natural talents, work style, social interaction, work-life balance,
whether or not you are looking to give back,whether you are comfortable in the public eye,
dealing with stress or not, and finally, how much money you want to make. If choosing a career
feels like too much pressure, here’s another option: pick a path that feels right today by making the best decision you can, and know that you can change your mind in the future. In today’s
workplace, choosing a career doesn’t necessarily mean you have to stick with that line of work for
your entire life. Make a smart decision, and plan to re-evaluate down the line based on your long-term objectives.

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