Kill Plastic Before It Kills Us

Plastic!!!! Yes it is one that has taken different forms to cater human needs since decades. It's uses got so deep rooted that it became a necessary evil to live with. It is a well known fact by now that though plastic has many uses, it has dreadful consequences in-terms of its disposal due to its non-degradable nature.

India alone  generates more than 5.6 billion  toxic plastic waste every year. As it is non-degradable, stays for years and when consumed causes serious health issues. As humans we know this and we just throw them off out of our premises without consuming. But do we really care about our environment? If not, at-least other creatures -animals like Cows, Dogs, Pigs etc that live in our surroundings that are highly prone to consume such disposed plastics. In earlier days, left out food and kitchen waste was thrown out which served as food source for some of the stray animals. Later with notion of becoming civilized, people started disposing waste by properly filling in plastics, tied and disposed.  Due to this many animals roaming around in our surroundings not knowing the effects of plastic, even eat plastic disposed openly on roads expecting to be filled with some food content. Years passed and in the name of "Swatch Bharat" in most of the cases directly the municipal sanitary workers come and collect garbage from home -to -home or firm to firm basis. On one side it is appreciable as it looks clean and tidy and minimizes growth and spread of undesired diseases through bacteria, mosquitoes etc. in residential areas. But there is other side of this novel idea of waste management that with this effort stray animals are completely snatched off their daily bread and many die out of hunger due to lack of food sources and lack of people who are sensitive to hunger of  roadside/stray animals. Anyhow this is another topic to be discussed.

Tale of Ramesh Gholap (IAS)

Ramesh Gholap (Ramu) from Mahagoan in Barshi Taluk, Solapur district of Maharashtra, had a difficult childhood. Make it further worse his leg was effected by polio. The family owned a cycle repair shop but the meager income that was just sufficient to sustain family of four, soon dried up as Ramu's father became a slave for habit of drinking. 

Ramu's mother then started selling bangles for the family to meet day to day needs. Despite being affected by polio, he and his brother lent a helping hand to their mother. When he was in class 12, his father passed away. 

His elder brother Umesh started working as safety manager in a private company. The family was rehabilitated at another place after their village was declared project-affected. After completing his graduation in arts, he joined as a primary teacher in a school. As he got more and more involved in social activities, he thought of joining the administrative services to improve the system. With this determination, Ramu first appeared for UPSC exams in 2010 after quitting his job but failed to get through. With persistence, he finally aced it two years later topping the Maharashtra Public Service Commission exam, scoring the highest ever marks of 1,244 out of 1,800. He cleared even UPSC examinations with a 287 AIR.

"Whenever I cancel the licence of a PDS shop owner who has been black marketing kerosene, I remember my days when I had to turn off lantern for lack of kerosene. Whenever I help a widow, I remember my mother begging for a house or for her pension. Whenever I inspect the government hospital, I remember my father's words when he had left drinking and just wanted better treatment. He would ask me to become a big man and take him to a private hospital. Whenever I helped a poor child, I remember myself, I remember Ramu," says Ramesh Gholap, IAS.

Tricky GATE/PSU Questions Part-2

Keeping GATE and PSU aspirants in view, few tricky/logical questions are being posted in the video:


Questions in the video are:

• The stress strain diagram for an aluminium alloy is shown below. If the specimen of the material is stressed to 600 Mpa and the the load is released , then the elastic recovery (in mm/mm) of the specimen is ____________
  

• Starting from rest, a particle moves along a circular path of radius 'r' so that the distance traveled is given by the expression 
  
   where c is constant and t is time in seconds. The radial component of acceleration of the particle is _______________

• Consider the following stress state imposed on a material -

If the material responds elastically with a volumetric strain , What is the bulk modulus???

For solution please watch the video below on youtube:

Tricky GATE Questions- Part 1

Keeping GATE and PSU aspirants in view, few tricky/logical questions are being posted in the video:


Questions in the video are:

• For an Ideal Gas undergoing a throttling process 1-2, which of the following relation holds good?

• Air is contained in one half of the insulated tank as shown in the figure below while the otehr half is evacuated completely. The membrane is punctured and the air quickly fills the entire volume. Calculate the specific entropy change of this insulated system.

• If a pure substance contained in a rigid vessel passes through the critical state of heating , its initial state should should be...     

a) Subcooled  Water                                             b) Saturated water

c) Wet Steam                                                        d) Saturated steam

• An ideal otto cycle (O) and an ideal diesel cycle (D) have the same maximum temperature and reject equal amount of heat. Also, the working fluid enters at the same state before compression. Which one of the following statements regarding their thermal efficiencies is always true?

For solutions please watch video below-

Basic Definitions and Concepts

The introductory concepts to Theory of machines are:

1. Defining Mechanism and machines
2. Types of Constrained Motion
3. Kinematic Pair and it's types
4. Link and it's types
5. Degrees of Freedom (DOF)
6. Kinematic vs Redundant Chain
7. Spatial and Planar Mechanisms with Grubler's Criterion
8. Equivalent Mechanisms 
9. Design of Kinetic Mechanisms ( introduction)
10. Mechanical Advantage
11. Transmission angle
12. Inversions of Slider Crank Mechanism (Introduction)

For above concepts please click the two links below:
Basic Concepts and Definitions Part-1
Basic Concepts and Definitions Part-2

Why Theory of Machines? What will you get from the course?

About the Course

Theory of Machines is an extension of Engineering Mechanics and preliminary for Machine Design. Those who are aspiring to work in the fields of Mechanical Design/Robotics etc. must have a basic understanding of the concepts of this subject.

In this course, few basic topics of Theory of Machines will be taught in GATE perspective with limited numerical (previous GATE Questions). Hence, this will be helpful for GATE aspirants.

The course study takes reference from GATE lecture notes and "Theory of Machines" textbook by SS RATAN

Postponing the Catastrophe (Part-1: Power Sector Issues)

There is no doubt that the advent of power and energy sector has transformed lives of humans by lot many folds. The mass generation of electricity has been started by thermal power plants (which are technically based on Brayton /Rankine cycles -Thermodynamic cycles). The heat source for these massive energy generation plants is fossil fuels such as coal which are hydrocarbon rich substances. When burnt for heat the fossil fuels react with oxygen to produce Carbon-Monoxide or Carbon Dioxide. Direct release of former into atmosphere harms Ozone layer while the latter leads to Global Warming. Damage of Ozone leads to direct aggression of UV radiation of Sun, the effects of which are known to every literate. On the other hand Global warming is main cause for forming a blanket at a height all around the earth which is capable of taking in the sun's heat energy but do not allow it back that easily. This leads to increase of Earth's surface temperature which inturn effects life and habitat of not just human but also other beings on the earth on one hand and melting of glaciers and ice caps at poles on the other. Again, the former effect is showing its form by snatching away the right to live for few species leading to their extinction. The latter effect leads to increase of sea levels  and drowning of a portion of low lying land at minimal or may even engulf few low lying countries. The waste steam (in Rankine cycle)or gases (in Brayton cycle) involved are at very high temperatures and these after expansion in turbines for power generation if let into nearby river bodies, adversely effect the river Eco-system.

Engineers' World

It is true that every work and profession has its own importance, uniqueness and contribution in maintenance of this Human World. But it's never will be a prejudice to appreciate the contribution of engineers.

Though GOD is one but depending on the need, we are able to see different manifestations of him. Similarly, though basic purpose of engineering is to make this world a better place to live, depending on the type of need it has leashed its different forms.

It all started in the form of Civil Engineering when man started living in colonies instead of woods and started stagnant life at one place instead of leading a nomadic life. Then Mechanical Engineering said Hi! with invention of wheel. Fire was invented leading to Thermal Engineering form. Slowly Chemical Engineering took its form in optimization of materials and substance use. We have to be grateful to GOD for giving us such beautiful brains. Human brain has consistently worked to make our lives better and easier. To make mechanical machines work without human effort Electrical Engineering has descended. Then man started thinking why to work all by himself when there can be a way to make machines work all by themselves. So Automation concept in the form of Computer science and electronics engineering came into existence and made our lives much much easier.