SEZINE is an annual magazine of Space Society of Mechanical Engineers (SSME),Published by SSME from Ahmedabad, Gujarat, INDIA. It's present chairman, is A R Srinivas, Scientist, Indian Space Research Organization, ISRO.

1. A PUBLICATION OF SPACE SOCIETY OF MECHANICAL ENGINEERS
Vol.9 No.1, 2011
GREENOVATION
Equipments Building 20 Tips Technologies Personal Train
have Ears First Time to Best that Flying: A your
Robust of FEA transform Reality Brain
Products our lives

2. CONTENTS Volume 9. No.1, 2011
Going Green: New Perspectives & Prospect of Green Engineering 1
Green Engineers try to lower the emissions of their products, develop devices
that consume less energy, creates viable renewable energy technologies and
better understands the global ecosystem
Interfering with Interference...!"DIDO” – A solution to the wireless problems 8
Data from a single satellite narrow position down to a large area of the earth's
surface a second satellite narrows position down to the region where two
spheres overlap and the third provides relatively accurate position
COTS in Space: An Up Coming Trend. 12
Converting a COTS product into a viable space product is not an easy
task but certainly not an impossible one either. Let's take a look on
how it can be done.
Non Linearity Simplified. 16
Non Linear FEA consumes lot of computing resources, adds to the cost of the product
and to time of realization. But if neglected and the applications demands the design
decisions made on the bases of Linear FEM could be catastrophic.
Equipments have “EARS”!!! 21
Micro vibrations based systems are widely used in health management. The
breakthrough technology called Micro Vibration Therapy cures swiftly and safely
without drugs and their side effect.
Building First Time Robust Products: A practical Viability! 24
20 Tips to extract best of FEA 25
Trends and Advances in Engineering 27
* Personal Flying Jet Pack Machine * Technologies that Transform our lives: * The Healing Power of Light: *
Nanogenerator Powers Up: * Tomorrow's Transistor, Built Atom by Atom
Train your Brain: Puzzles & Solutions. News & Views: * Cool Webs: * How to drill polygonal holes?: *
Does F really equal ma?: * A Few Facts about our planet: * Life is Echo!!!!. SSME news: Journal: Memoir: Honorary
Members: Website: New Members.
On the Lighter Side: *Poetry: *Jokes: * Proverbs at Work: *Engineering Clocks: *Laughtoons: *Neck Exercise: *

3. EDITORIAL
"Transformation" is the Key
Scientists & Engineers to make impact on Global Green Economy
A.R.Srinivas, Chairman, JME & Vision, SSME arsrinivasu@yahoo.com
The World Economic Forum was recently concluded in Davos. The theme of the year was "transformation". Global leaders
from government, business and civil society felt reshaping our global economy is a vital task and can be achieved through
strong, green global economy for the 21st century as climate change is integral to a robust and resilient economy.
A glance of the data alarms us. "Globally, 2010 was the warmest year on record, with 2001 to 2010 the warmest decade.”
2010 is the 34th consecutive year with global temperatures above the 20th-century average." With rising temperatures we
can expect to see more extreme weather events, including more frequent and intense droughts, floods and other natural
disasters. The environmental consequences translate readily into economic costs - as well as potential negative impacts on
water security, coastal development, infrastructure, agriculture, and health. The evidence of atmospheric warming is very
strong, and the potential for dangerous climate impacts is high. The scientific advice and dire need is to control 'carbon
pollution' .
pollution'
In the national interest, it is indisputable to say that the Government has a responsibility to play a leading and vital role,
nevertheless, as the adage goes" Small beginnings make great endings”. To have a successful pollution free and minimal
carbon foot print economy every individual should play a responsible role in the international efforts to tackle climate
change and reduce pollution. The world leaders have already planned to "pricing carbon” to ensure that the International
economy of the 21st century remains globally competitive. Therefore, Engineers and scientists worldwide have the unique
opportunity to make a bigger impact on the environment than any government policy.
bigger
Drawing cue from these strings, we made a little effort by devoting the kick off article in this new edition of SEZINE (Vol.9
No. 1 ) towards "Greengineering", a Cradle 2 Cradle approach and principles to implement it through and the role every
engineer has to play in reducing carbon footprints and in saving material, cost and time by reducing the energy
consumption of the products and processes we design and deal with.
With this launch, yet another issue of the transformed SSME’s magazine will be in your hand and on your screens. A
completely techno packed edition will take you through " How to interfere with interference ", "Handling Non linearity with
ease", " COTS into space", "Humans Flying high in air ", " Does F really equals 'ma', " Have guffaws, through laughtoons,
cracking your heads through puzzles and many more on poetry, jokes, proverbs exercises etc, contributed by young ,
budding and enthusuastic engineers. Hope so, these little efforts will help and motivate more engineers amongst us by
unraveling the latent talent and making the world a better place to live in such a way that a clean energy future delivers a
clean environment and sustainable prosperity.
So get "transformed" , keep reading and write to us on what you felt. Send us your suggestions, comments and your valuable
transformed"
ansformed
contributions through email or letters, which, we will be eager to read and publish.
Before, I sign off; I would like to "grignite" your thoughts to be ready for “Green Beds", Green Mouse, Green Cars, Clocks
running with compost and many more as Green Products knocking your doors before we come back with another issue..!
A.R.Srinivas
R.Srinivas

4. MESSAGE FROM THE PRESIDENT
Shri A. C Mathur, President, SSME. acmathur@sac.isro.gov.in
Space Society of Mechanical Engineers (SSME) is a society dedicated to disseminate the knowledge base in the field of
Mechanical Engineering and allied Sciences. There are challenging roles for Mechanical Engineers in the development of
the space payloads as well conducting research in the fundamental materials, processes and new manufacturing
technologies. Today’s Mechanical Engineers are more towards handling multi-disciplinary tasks and projects interacting
with RF, Optics, chemical, metallurgy and Computer science disciplines and hence they play a vital role in the building the
engineering base which can be used for the betterment of the society.
The society has been quiet successfully in all its past endeavors in fulfilling many of its objectives with support of many
engineers around the country. I take this opportunity to acknowledge all your efforts in building this society of national
repute and welcome many budding new engineers to come and join us in taking the onus of carrying the baton further
ahead and take the society to new heights of success.
On the occasion of release of the SEZINE ( Vol.9. No.1) the InnoVision of SSME. I am indeed happy to find that SSME has
advanced further in abundance in bringing you a new piece of fully packed information completely in an e-format. The
contents of the magazine are very relevant to current challenges faced by many mechanical engineers and hope that it will
serve as a useful tool to all SSME members and even other engineers in general.
I congratulate Editorial Board, Chairman and his team for their excellent and stupendous work done in bringing out the
new version of the Vision in electronic format called se-zine. I wish them all success and encourage them to bring many
such issues of the magazine in the future.
Anil Chand Mathur

5. Tech. Articles
"Green Engineering" by using highly essential for us to
Going Green: New innovative design, "Remake the way we make
perspectives and manufacturing, measurement the things", introduce
prospects of Green and control techniques to "Cradle to Cradle" products
Engineering
Engineers and scientists around the world who have
Mind boggling pollution Numbers, the unique opportunity to make a wider impact on the
Depletion of natural resources and society and environment are now looking at one of the
ozone layers, Rising Carbon largest challenges society faces. They are leading an
Footprints are burning issues....! effort called "Green Engineering"
Wake up Call for Scientists & develop, and improve and evolve at sustainable
Engineers. products, technologies, and solutions for enabling
processes resulting in ourselves to have biogenic life
environmental and economic on earth. While green
R ecent past has witnessed
benefits. Green engineering
provides the tools, techniques,
and technologies to foster this
revolution in engineering
design has already wrung its
tentacles in almost all of the
dramatic changes in the global
environment on many innovation. For example, worldly affairs, it is a high time
important issues. 'Going advanced manufacturing that we take a peep into the
Green' is the most important techniques like desktop digital green philosophy and embed
amongst all. New priorities and product building, advanced the culture into our day to day
expectations are rising on the multi-domain-physics engineering life. Let's start
concerns of global climate simulations, graphical system introducing it.
change, soaring energy prices, design, high-speed and high-
and increased government resolution measurements,
Green Engineering Defined
legislation. Right from fast advanced analysis and signal
moving consumer products to processing, environmental
emissions monitoring Green
to engineering is a
corporate responsibility and
advanced engine simulators mechanism or a means used
sustainability plans industries,
to
for next-generation hydrogen- design, develop, and
big and small, around the
improve products,
world are scrambling
to not only create Green Engineers try to lower the emissions of their products,
products and develop devices that consume less energy, create viable
technologies that
address these concerns
renewable energy technologies and better understand the global
but also to change the ecosystem.
procedures and
based vehicles , high-speed technologies, and processes
processes they adopt to meet
and sophisticated control, and that result in environmental
the herculean tasks. Engineers
embedded system technology and economic benefits.
and scientists around the
world who have the unique provide a wide range of
opportunity to make a wider enabling technologies which Green Engineering can also be
impact on the society and have already penetrated in the defined as developing
environment are now looking industry. They are environmental caring
at one of the largest demonstrating the positives of attitudes, values and principles
challenges society faces. They sustainable and green which bind science, technology
are leading an effort called engineering initiatives. It is and, engineering practice, all
"Innovation distinguishes between a leader and a follower." Steve jobs

6. directed towards improving the next generation of "Cradle-to-Cradle" (C2C)
local and global environments. products and technologies with system powered by renewable
improved efficiency and energy, in which materials
Well, performing green flow in safe, regenerative,
reduced environmental impact.
engineering is fundamentally closed-loop cycles.
Some industries enable green
no different than any other
engineering by eliminating
conventional engineering
practice. First, you need to metal cutting and resort to
measure the variables with only metal building layer by
which you are concerned, and layer to form the product and
then you can begin the saving not only material being
process of designing or fixing cut, but also the power, effort
products and processes that and the environmental
achieve your desired goals.
damage in the process
Green engineering
encompasses common
measurements such as power "Green Engineering" A cradle -
quality & consumption; to- Cradle approach: Contrary to the historical
emissions from vehicles and approach of industrial problem
factories, such as mercury and solving, which often involves
One simple and straight
nitrogen oxides; and fine-tuning a fundamentally
forward procedure to adapt
environmental data, including flawed system, the C2C
green engineering philosophy
carbon, temperature, and framework articulates this
is, “Doing the right things
water quality. Green conceptual shift. The C2C
right”. Well...! It's not as easy
engineering also involves framework is a science and
as it sounds. Working smart
minimizing material and values based vision of
may be easy, but working
process wastage in sustainability that enunciates a
smart without perspective or
manufacturing, minimizing
/eliminating product testing for One simple and straight forward procedure to adapt green
evaluation etc.
engineering philosophy is, “Doing the right things right” with a
fundamental conceptual paradigm shift away from the current
Engineers, who want to lower
the emissions of their system of Cradle-to Grave to Cradle-to-Cradle system.
products, develop devices that
consume less energy, create guiding principles can positive, long-term goal for
viable renewable energy ultimately become an efficient engineers. C2C propels the
technologies, or better pursuit of the wrong goals. design of a commercially
understand the global productive, socially beneficial
ecosystem need green and ecologically intelligent
So, one should have right industrial system.
engineering.
goals, and the right tools. If
we approach sustainability (a
For instance, some industries life cycle assessment of C2C in perspective:
implement green engineering product and process) from a
by providing measurement, design perspective, we can see A simple text book definition
automation, and design tools the need for a fundamental & does not enable “The C2C”
that empower engineers and conceptual paradigm shift framework to reach for
away from the design of the sustainability. From an
scientists to first quantify and
current system, which engineering perspective,
understand real-world data generates toxic, one-way, conventional sustainability too
and, second, correct problems "Cradle-to-Grave" (C2G) often suggests retrofitting the
by designing and developing material flows, toward a machines of industry with
“First they ignore you, then laugh at you, then they threaten you , then you win” Mahatma Gandhi

7. cleaner, more efficient tree to use for growth. textiles and packaging made
"engines" to secure ongoing Precisely, the nature's systems from natural fibers, can
economic growth. is built in a way that one biodegrade safely and restore
Sustainability can be obtained organism's waste, is food for soil after use. Materials
by developing strategies of another so that the nutrients designed as technical
“doing more with less" or flow indefinitely in C2C cycles nutrients, such as carpet yarns
"reducing the human footprint" of birth, decay and rebirth. In made from synthetics that can
to minimize troubling other words, waste equals be repeatedly depolymerized
symptoms of environmental food. and repolymerized, are
providing high quality, high-
Like the fact that, waste does not exist in the tech ingredients for generation
ecosystem, engineers and designers have to after generation of synthetic
recognize that all materials can be designed as products.
nutrients that flow through natural or designed
metabolisms. Tapping Solar Income:
decline. Another viable way of
Like the fact, that waste does
embedding Green Engineering
not exist in the ecosystem,
is by use of solar income. We
Therefore, C2C framework is a engineers and designers have
appreciate the fact that, living
means of providing the natural to recognize that all materials
world, a model for "Human
Designs". Recall that, the Designers and engineers can use scientific assessments
natural systems largely to select safe materials and optimize products and
operate on the free energy of services, creating closed-loop material flows that are
the sun, which interacts with inherently benign and sustaining.
the geochemistry of the
earth's surface to sustain can be designed as nutrients
things thrives on the energy of
productive, regenerative that flow through natural or
the sun. Trees and plants
biological systems. Human designed metabolisms. While
manufacture food from
systems designed to operate nature's nutrient cycles
sunlight, an elegant, effective
by the same rules that govern comprise the biological
system that uses the earth's
the natural world can approach metabolism, the technical
unrivalled and continuous
the effectiveness of the earth's metabolism should be
source of energy income.
diverse living systems, in designed to mirror them in a
Human energy systems can be
which the waste almost closed-loop system in which
nearly as effective as natural
approaches zero. valuable, high-tech synthetics
systems. C2C systems from
and mineral resources
buildings to manufacturing
Implementing a C2C system: circulate in cycles of
processes tap into current
"production, use, recovery and
solar income using direct solar
remanufacture".
To quote a natural energy collection or passive
regenerative ecosystem, let's solar processes, such as day
Designers and engineers lighting, which makes effective
discuss simple examples. A
should use scientific use of natural light. Wind
fruit tree's blossoms fall to the
assessments to select safe power-thermal flows fueled by
ground and decompose into
materials and optimize sunlight also are tapped.
food for other living things.
products and services,
Bacteria and fungi feed on the
creating closed-loop material
organic waste of both the If you are yet, not clear on
flows that are inherently
trees and the animals that eat how to implement the Green
benign and sustaining.
its fruit, depositing nutrients in engineering? Principles of
Materials designed as
the soil in a form ready for the Green Engineering proposed
biological nutrients, such as
“Leadership and learning are indispensable to each other." John F. Kennedy

8. by William McDonough, M. Green Engineering, Technology Engineering yields can be
Braungart, Paul Anastas, Julie viability and Business appreciated by looking at the
Zimmerman, provide guidance following case studies.
Opportunities.
to tap the benefits in the
design of engineering products Success Stories of Green
using C2C approaches Industry has witnessed many
successful implementations in Engineering
real world problems. Green
Principles of Green Engineering: Engineering has now become a Nucor Steel (a steel major in
viable technology reaping U.S) recycled more than 22
• Ensure that all materials and profits for many industries. million tons of steel, including
energy inputs and outputs are Green engineering applications 9 million cars.
span almost every industry www.nucor.com.
inherently non-hazardous.
• Prevent waste rather than treat / and range from monitoring the
health of forests, graphical
clean up waste.
software to measure and fix,
• Separation and purification High-speed and high-
operations designed to minimize resolution measurements,
energy & materials use. Domain-specific analysis
• Products, processes and systems libraries, FPGAs for advanced
designed to maximize mass, control to building engineering
energy, space and time products, All contributing
efficiency. further to our day to day lives. In Europe, the End-of-Life
• Use catalysts, not stoichiometric Vehicle Directive, made the
reagents. The technology components manufacturers responsible for
required for green engineering automotive materials, is
• Products, processes and systems
are not only accessible but encouraging companies to
should ‘output pulled’ rather than
also easier to use and consider design for
‘input pushed’ through the use of disassembly and effective
energy and materials. available at a lower price than
ever before. There is a huge resource recovery more
• Recycle the materials.
• Targeted durability, not
immortality, should be a design There is a huge opportunity for profit and savings in
goal. green products. With oil prices surging to all-time highs,
• Design for unnecessary capacity demand continues to be strong for technologies and
or capability solutions should be products that help companies use less oil in their
considered a design flaw. machines and processes while achieving the same output.
• Material diversity in multi
component products should be opportunity for profit and seriously. Cradle-to-cradle
minimized to promote savings in green products. systems, in which materials
With oil prices surging to all- either go back to industry or
disassembly and value retention.
time highs, demand continues safely back to the soil, are
• Design of products, processes
to be strong for technologies built for effective resource
and systems must include recovery. In such a system,
integration and interconnectivity and products that help
companies use less oil in their each part of every car is either
with available energy and returned to the soil or
machines and processes while
material flows. recovered and reused in the
achieving the same output.
• Products, processes & systems to assembly of new cars,
Other companies, looking to
be designed for performance in a avoid steep fines for non generating extraordinary
commercial “afterlife”. adherence to environmental productivity and consistent
• Material and energy inputs should regulations, are buying employment.
be renewable rather than monitoring and reporting tools.
depleting. The penetration of the Green
“Be courteous to all, but intimate with few, and let those few be well tried before you give them your confidence.” George Washington

9. Efficiency of modern large materials. Possibly remotely
internal combustion engines controlled space vehicles
has been tremendously which can capture the debris
improved using green serve as refueling depot to
principles. A simulator was charge and replace the
developed for this purpose hardware in the present
which is used for both the satellites to extend the life and
development and validation of missions of the onboard
controllers by simulating the payloads.
inputs from the engine and
Space mechanical engineers have complicated
Green Car
challenges in containing the space debris and
developing reusable, satellites, launch vehicles and
materials. Possibly remotely controlled space vehicles
which can capture the debris serve as refueling depot to
charge and replace the hardware in the present
satellites to extend the life and missions of the onboard
payloads.
Have a visual glimpse of the
acquiring the output data from some of products already
the controller. benefiting the human race.
Green Bed
Digital Desktop Manufacturing Be a part of It.!
is another successful example
of green engineering
Are you ready for these
eliminating significant amount
challenges..!
of wastage in materials, time
and cost of manufacturing.
Green engineering has as well
pervaded into many other
products. A green car, Green Green Mouse
Bed, A growing Chair, Green
Mouse are some of the
examples.
The Green clock, powered by a Super Futuristic Green Car Design
safe chemical reaction
between mud and metal
electrodes, displays the time
without the need for additional
power sources. (Designers:
Francesco Castiglione Morelli & Growing Green Chair
Tommaso Ceschi)
Space mechanical engineers
have complicated challenges in
containing the space debris Organic Self Growing House Design
and developing reusable, Contributed by: Vikas Sinha &
satellites, launch vehicles and A.R.Srinivas
"Those who think ahead of their times are sure to be misunderstood.” Swami Vivekananda

10. GREENOVATION
Sustainable Living Walled Skyscraper
Stackable Futuristic Public Transit Cars
Origamic Emergency Relief Shelter
Designs
Green Clock
Beautiful Natural Green Research Complex
Super Vegitated Sustainable Community
Design
Green Roof House
High Tech Luxury Green Resort
Portable Prefab Stadium Performance
Space
Green Knuckles
Eco-Friendly Lakeside Housing Complex
Rapid Prototyping

11. NATURAL C2C SYSTEM
ATMOSPHERE
WATER CYCLE
OCEAN
CARBON CYCLE
SUN LAND

12. introduced the problem of
Interfering interference grew exponentially
with with large number of users
simultaneously receiving and
Interference...! transmitting independent
communications. There also
"DIDO” – A solution to the
existed the interference
wireless problems.
problem. This problem was
solved by the concept of cells
A re you annoyed with call with a mile or less in diameters
at different frequencies that did
Nevertheless, a given cell has
limited data rate capacity . Once
drops, slow and/or unreliable
internet on your mobile? Read not interfere with each the data rate of the cell is
these paragraphs ahead to other. reached the users would not get
understand who the culprit is the required data rate capacity
and how to get rid of it. they needed. This is why you
see that, your call is dropped
Interference is felt whenever
and may be your connection is
there is more than one wireless
lost.
transmission in the range of
another. This is what you mostly Again to fomulate solutions and
feel while driving and give the service to their
approaching/leaving the ranges Then came rapid technological
customers the service providers
advancements in
resorted to capacity building
Whenever there is more than one the mobile and
measures by adding new towers.
wireless transmission within the internet industry
To their utter surprise the
range of another, there is a potential which resulted in
demand for the higher rates
for interference between them the cost and sizing
grew much faster as wireless
of mobile phones
video has become a majority in
of AM/FM radio transmissions. where the service providers
the data traffic. These together
This is ensured placing the coming up with number of
ultimately resulted into
commercial stations far apart schemes that enabled more and unreliable , low quality web,
with limited transmission powers more
and each transmitting one signal customer MIMO is an advanced digital transmission
to many users. So the problems s to the techniques using multiple antennae at both the
were solved in the yester years join the transmission and receive ends to improve the
by the broadcasters limiting the band performance of the communication
power to control the wireless wagon of
video or videogame experiences.
interference. cellular community. The
interference problem was again
Looking for the reason?
an issue. MIMO (Multiple Input
and Multiple Output) using Shannon’s law look’s to be the
multiple antennae at the input one restircting us. The
and output to improve the multiuser spectrum capacity
performance of the using conventional wireless
communication came to the techniques is due to shannon's
When cellular phones were rescue. law which defines the maximum
“The quality of a person’s life is directly proportional to their commitment to excellence, regardless of their chosen field of endeavor.” Vince Lombardi

13. amount of error free data rate Shannon’s law. The reared
group president who holds a
Shannon’s law defines the maximum amount of error
patent for this technology claims
free data that can be transmitted through a single
that though there could be a
communication channel for a given amount of spectrum
theoretical limit to how many
and noise level called spectrum capacity users could be added to the new
system , but presently
that can be transmitted through
a single communication channel DIDO is a wireless technology, a novel approach to multiuser
for a given amount of spectrum
wireless, allows the number and density of users in the same
and noise level which is usually
area to be steadily increased without additional users
referred to as “Spectrum
reducing the data rate of other users.
Capacity”. That is a cellular
sector say spanning a kilometer,
whose maximum data rate is nowhere close to the limit. They
limited by the shannon’s law claim that, when the Shannon
will be sharing the data capacity The next generation Solution: limit is 10X, they have already
of the this sector only. Users in demonstrated 100X and are
DIDO (Distributed input confident of reaching 1000X.
Wi-Fi netwroks at the same
distributed output) network was
frequency are also limited by
rolled out to supplement today's This is How a DIDO works:
shannon’s limited data capacity
cellular network, so as to, break
law.
the barriers of limited Assume that there is a User1
downloading speeds. DIDO and wishes to reach a position,
Even somebody may argue that a website through an access
technologies like beamforming involves intentionally combining
point, AP1. When the user1
and advanced MIMO’s can lead signals from multiple clicks on a website 1 to
to 3X, 4X data rates. As transmitters, exploiting request a video stream , the
witnessed in the last decade has interference to create a bubble video data from the website 1
exponential growth of very high of crystal-clear reception around is not sent directly to AP1. It
every user. Each signal that first reaches a DIDO data
data rate users and a huge
leaves an individual transmitter center that supports the
is incomprehensible until it
A Conventional System encounters, and interferes with, The DIDO System
other DIDO signals bubble near
a device connected to the
network. The size and shape of
the bubbles varies depending on
the number of antennas
broadcasting to a device. DIDO
is multi-user wireless technology
that allows the number and
density of users in the same website AP1 and the user1.
demand by consumers made The DIDO data center then
area to be steadily increased
existing mode of communication processes the data ,
without additional users
virtually blocked and prone to modulates it into a radio signal
reducing the data rate of others.
problems. waveform and sends the
DIDO bid’s a goodbye to
“An investment in knowledge pays the best interest.” Benjamin Franklin

14. waveform to AP1 which simply located or which users owns Sounds Amazing isn’t!
sends the waveform to its what. Each user get the data
antenna Looks like we
and have lot more
transmits The Multiple User DIDO System entertainment
it as a
on the Web for
radio
signal. the years to
User1 come , no
computer concerns of
receives loosing
the radio connections
signal , and call
demodula
dropping, A big
tes the
waveform boon for us it
into data yet to dawn.
and plays
back the Interested
from the website they are
video. more in the topic and would like
connected to through an
to have answers to,
Similarly, when the second independent wireless channel.
User2 is added for another AP2, How is DIDO able to create
Not only the 100% data rate the
the DIDO combines process waveform that summed
DIDI offers clear signal quality
both the inputs and together at each user still result
and the reliability much higher
simultaneously through DIDO in a clean waveform?
than the Wi-Fi or cellular
and get the radio signals back
system. Also for a given range,
to the respective users without With Many users sharing the
less wireless power is needed to
loss of any data or the same spectrum why doesn’t
operate and maintain a DIDO
bandwidth sharing and most Shannon’s law limit the data
system.
important without any rate?
interference from the other
DIDO also ensure that both the
sources or with each other. How to visualize the DIDO
channel and at what frequencies
DIDO communication uses a DIDO data center which it operates?
process the data, modulates it into a radio signal
waveform and sends the waveform to respective access How is DIDO with respect to the
points, which further sends the waveforms to its antenna conventional channels in latency
and lag?
and transmits it as a radio signal which will be received
by the user. Do log into rearden’s website
and quench your thirst.
Similarly even if we add up five
AP’s and the radio of the user
users and five AP’s, There is no
devices (mobile, tablet, laptop
interference among the 5 users
etc) are much simpler than a
and all the five users get the
conventional Wi-Fi or cellular
benefit of 100% of the data rate
radios.
of the channel and doesn’t Contributed by: Piyush Shukla
matter where the APS’s are & A. R.Srinivas
“Failure comes only when we forget out ideals, objectives and principles.” Jawaharlal Nehru

15. DHAVAL ELECTROMECH INDUSTRIES
5, DHANLAXMI INDUSTRIAL ESTATE, NEAR POLICE COMM. OFFICE, SHAHIBAUG
AHMEDBAD 380004 (GUJARAT-INDIA)
Ph: 079-25628851 Fax: 079-25633437 Mob: 9825484343
Email:info@dhavalelectromech.com website: www.dhavalelectromech.com

16. own satellites". Satellites are and amenable novel
COTS in Space: shedding volume and mass but technologies to space.
An Up Coming they are growing in number.
Cost in aerospace segment is Commercial hardware in
Trend. being questioned in today’s ever space
Are the costs spent on
development of space products
Space has been a specialty domain for many years
worth enough? Are we going now. This always demanded highest reliability at all
to sustain them in the future? levels, rendering every space endeavor a costly affair.
Are these questions disturbing
competitive economic scenario. Space is a completely different
you....? Read ahead...!
The specialty domian of space, place as compared to the
exclusively controlled by state, atmosphere of our planet.
S pace has been a specialty is now slowly drifting towards an
enterprise with more private
However, as a matter of fact,
if a commercial system is
domain for many years now. participation, moving up the designed for a specific
This always asked for the hierarchy. function, it principally also
highest reliability at all levels, works in space most of the
rendering any space endeavor a Space was marked by reliable times. A camera designed to
costly affair. A system cannot products. This reliability comes take pictures in earth’s
inherit reliability. It has to be at an exorbitant cost to the atmosphere will take pictures
built in from its very roots to the national exchequer. Gone are in space as well. However, it
final form. In other words, the days...! It has to now has to be evaluated for
almost every space hardware is compete against the cost factor. following aspects before it can
exclusively designed, fabricated Use of commercial off-the-shelf fly. There are five major evils
and tested for its very purpose (COTS) hardware in space which restrict commercial
products to space use
A paradigm shift is in the happening. A common man is
1. Launch loads: A
now seeking access to space as a tourist, Undergraduate
commercial system is
student, opting to build satellites on their own. The
generally designed to take
upswing is on.
loads that may come during its
to inbreed reliability. This takes performance and during
dramatically brings down the
time, calls for specialized and logistics transport. Space
realization cost and time. This
skilled manpower and demands transport generates much
looks more appealing when
high budget. higher dynamic loads. Using
critical and rare launch windows
commercial hardware as it is
are targeted. The transfer of
As nothing is constant and can lead to catastrophic failure
new technological developments
change is supposed to happen, during launch itself.
to space segment is sluggish.
this trend, however, is going
There are five major evils which restrict commercial products to
through a change, a paradigm
space use. Launch loads, Thermal Management, Contamination,
shift is in the happening. We
have already come across facts
Interfaces & specifications and Radiation.
such as, "a common man is now 2. Thermal management:
Use of commercial components
seeking access to space as a Space hardware invariably
gives the advantage of viable
tourist", students, building their
“In order to succeed, your desire for success should be greater than your fear of failure." Bill Cosby

17. entails some electronics that great concern for ground presence of each part in the
dissipate heat as systems are systems while every extra product. May be at times, you
not hundred percent efficient. gram on space pinches the need to dismantle the parts
Remember convection one of launch cost. and get back to it. If so, it's a
the dominant mode of heat good practice to document all
transfer is absent in space 5. Radiation: Earth action by photographs and
thus resulting in hot spots, environment shields all high videos. Also note that special
high working temperatures or energy radiation from entering tools for dismantling and
total burn out. the atmosphere and hence this solvents can also act as aid in
deleterious effect of radiation dismantling process, and may
3. Contamination: hardware is not a point of consideration need to be designed and
used for commercial in the design of a commercial fabricated for this purpose.
applications is always under hardware. While in space, high
atmospheric pressure, which energy particles start Strip the hardware to
keeps check on out-gassing (a impinging the electronics, reducing mass and power:
phenomenon of mass loss and deteriorating its performance Eliminate all the parts which
condensation in vacuum.) and may result in "run away". may not be useful to you
Contamination is not prime Polymers materials mainly without hampering the
factor affecting performance dominant in commercial use functionality. This could shed
for the ground hardware as it lose integrity and start to most of the unwanted mass in
is manned and maintenance decay under the shower of the product. For example if
activities can take care. In high energy particles. you are working on a
space, vaporization of volatile commercial camera, the focus
materials can play havoc. Up gradation for space ring can be discarded after
Vapors can get deposited on worthiness setting lens on infinite focus.
functional surfaces like lens
and mirror of imaging systems Contact conductance of interfaces increases drastically as
or detectors. It may affect
the molecules of air, which acts as thermal bridge between
other special sensors like mass
the voids of interfacing surfaces is completely removed.
spectrometers and can ruin
their very function. The multi-leaf mechanism of
Converting a COTS product
aperture control can be
4. Interfaces and into a viable space product is
replaced with compact disc
secondary specifications: A not an easy task but certainly
with fixed aperture hole. Other
commercial hardware will have not an impossible one. Let's
areas which help you in
its own unique foot-print with take a look on how it can be
shedding mass could be
specific mechanical and done. First, identify the
switches, potentiometers and
electrical interfaces. It may product you need to ruggedize
other control items replaced
not be feasible to adopt them to a space use, and then
with jumpers, resistor pairs
in as is forms for a spacecraft thoroughly understand its
etc. Extra length of harness,
bus. Moreover, Mass is not a characteristics and functional
internal connectors etc can be
Converting a COTS product into a viable space product replaced with direct harness.
is not an easy task but certainly not an impossible one Power conditioning circuits
either. Let's take a look on how it can be done. may prove redundant if
satellite bus can provide
“There are no great people in this world, only great challenges which ordinary people rise to meet." William Frederick Halsy, Jr.

18. regulated power output. gradients produced. There are compounds can undergo decay
Cooling fans can be replaced. various ways to dissipate heat if they see adequate humidity.
Caps and dust covers, parts from the components to the Some optical filters carry
for aesthetics, logos, supports chassis. Addition of thermal organic dies which can even
etc can be discarded or control materials like, grease develop fungus on it.
replaced with light weight or indium sheet as thermal Thorough ultrasonic cleaning
parts. Sparsely located parts interface material, high in isopropyl alcohol or acetone
can be densely packed. The conductivity potting and of all hardware gets rid of
chassis of the system could be graphite thermal shunts can major contaminants. In
optimized for structural improve contact conductance addition, such systems have to
stiffness, thermal stability and to bring down the peak be kept under observation and
intended functionality. temperature of the devices. controlled climate.
Meeting Environmental Testing of the Hardware Interface design: Mechanical
Specifications: The existing Testing of the products interface can be developed
commercial system should be created from commercial items either as an external
modeled as conventional space is very essential to reveal any component or by replacing the
product design to look for untoward and lateral chassis with a new design.
vulnerabilities in the design properties of the materials and Electrical interface can be
and validate the design the processes used in the accommodated by appropriate
parameters for complete set of product development. selection of the hardware
environmental loads and Therefore subjecting them to specification in first place. If
specification in which the rigorous space qualified tests that is not feasible, suitable
product is suppose to operate. would be highly advisable to conversion has to be designed
develop a ruggedized product. at the tail end of data chain.
Thermal Design and Thermal cycling, vacuum and
Control: Thermal design of vibration, shock, humidity and Protection against
the product and the correction storage tests will be of radiation: The greatest
the commercial product has to immense help. Note, reliability challenge for
undergo, needs to be given commercial devices have lower systems in space is the
special emphasis to keep away allowable temperature as constant bombardment by
surprises later in the compared to mil grade radiation. Designing for
ruggedized products. Contact components. radiation tolerance is fast
conductance of interfaces
increases drastically as the Commercial products use many oils for lubricating the
molecules of air (which acts as joints which in space environments can degrade the
thermal bridge) between the functional performance. Organic compounds can
voids of interfacing surfaces is undergo decay if they see adequate humidity.
completely removed. Use of a Contamination control: becoming an art which system
thermal scanner could be a Remember, commercial engineers must undertake far
wise decision to critically products use many oils for in advance during the design
understand and evaluate the lubricating the joints which in process. Severity of the
hot spots and the conduction space environments can radiation depends on the
paths. A rationale can then be degrade the functional space mission objectives. Low
established correlating the performance. Organic earth orbit mission do not see
heat dissipated and the much of the radiation. Those
“The definition of insanity is doing same thing again and again and expecting a different results." James Robbins

19. crossing Van Allen belt or errors. Figure shows the existence by the end of 2012,
going far distances see a good mechanism of neutron strikes. when a tiny satellite the shape
amount of radiation. Figure of a compact disc rack will be
below explains the severity of blasted into space on top of a
altitude. converted intercontinental
ballistic missile. The boxy
shape of the UK‘s first official
‘cubesat’ is a testament to an
approach that is all about
These changes, or upsets, may using COTS parts and concepts
occur in digital, analog and to open space up to a wider
optical components or may variety of users. There are
have effects in surrounding many such upcoming tales of
Memory devices are most
circuitry. Devices can be the utilization of COTS in the
vulnerable to radiation attack
shielded with materials like design, development and
and should be checked for
tantalum or strategically realization of space payloads.
their sustainability limits by
placed in spacecraft for The expected reliability with
exposing them to radiation
maximum resistance. Using commercial system is on a rise
source. The solution chosen
and the pressure to reduce the
The greatest reliability challenge for systems in space is cost on space mission is also
the constant bombardment by radiation. Designing for building. Mechanical Engineers
radiation tolerance is fast becoming an art which have to play a greater role in
system engineers must undertake far in advance during “ruggedization” of COTS
the design process. products for space use.
anti fuse and flash based So be a part of the mission
should offer very high and participate in national
devices can be used to get rid
reliability against radiation development.
of SEU's. A newly designed
that can cause single-event
FPGA based anti fuse
upsets (SEUs), or changes of
developed by ACTEL (RTAX-S)
state in a device induced by an
family provides a good
ionizing particle such as a
solution for SEU's by
cosmic ray or proton. When
enhancing the gate counts
neutrons strike silicon atoms Contributed by Anurag Verma
forming successful
in devices heavy ions are & A.R.Srinivas
replacement in space payload
The biggest success of the applications.
COTS developed space payload
will come into existence by the
end of 2012, with launch of
tiny satellite, CUBESAT.
ejected causing momentary
current pulses in IC's which in The biggest success of the
turn can affect the quality of COTS developed space
the data amounting to soft bit payload will come into
“A picture is worth a thousand words…a good prototype is worth a thousand pictures." Tom Kelley

20. and the applications demands often yielding is not the only
Non Linearity the design decisions made on mode of failure, it is also
the bases of LFEM could be necessary to consider
Simplified. catastrophic. displacements to ensure the
part or assembly does not
If you believe that linear deform too much. Another
analysis of engineering
systems is enough or you are The critical Buckling load for any structure is
much fearful about non-linear calculated by performing a linear buckling analysis to
analysis, these paragraphs are predict a Buckling Load Factor. The BLF value of the
for you...! structure is then multiplied by present load value to get
the critical buckling load of the structure.
M any a time we, the design In conventional design
practice, engineers resort to
important aspect is buckling
which more often belongs to a
engineers limit ourselves to calculate the factor of safety forgotten lot. But remember
performing linear finite- (FOS) to ensure that the buckling poses a catastrophic
element analysis (LFEM). LFEM design will withstand the mode of design failure as
does not provide enough expected loadings. The risk buckling happens suddenly,
information about the involved is correctly without little, if any, prior
structures to make correct recognizing the mechanisms of warning. So there is almost no
design decisions, especially failure and is most important & chance for corrective action.
when designing lightweight difficult task. The following table shows
most prominent modes of
Non Linear FEA consumes lot of computing failure and their attributes.
resources, adds to the cost of the product and to time
of realization. But if neglected and the applications
In order to highlight the
demands the design decisions made on the bases of importance and effect of the
Linear FEM could be catastrophic. linearity and non-linearity in
the design of components, we
components. For example a In the conventional practice, it take a simple case study of a
buckling analysis shows is customary to associate all cantilevered beam with a free
contradictory results for linear the structural failures only to end axial load to perform a
and non-linear linear buckling
cases. It is analysis or modal
important and analysis and non
imperative to linear buckling
consider the effect analysis. Before
of non linearity that, is essential
(NL) in the design. that we clear up
To demonstrate the our fundamentals
role and impact of on linear and non-
the NL, buckling of linear analyses
beam is used as an using FEM.
example. It is clear
that NLFEA
consumes lot of Linear Analysis:
computing Linear Finite
resources, adds to the cost of yielding. The designers are Element Analysis though
the product and to time of then content with sufficient extensively used for analyzing
realization. But if neglected FOS related to yield. Most displacement and stresses of
mechanical components, it is
“You will never be a leader unless you first learn to follow and be led." Tiorio

21. not a fool-proof way to analysis, which doesn’t take over-predicts buckling load,
validate the design of the the factor of elasticity into nonlinear buckling analysis is
component. This is because account. The values of recommended. Please not that
Static, Nonlinear with P-Delta
and large displacement is the
Non-Linear Buckling requires a model with model with
load case type for non
some initial imperfections. They must be added to control buckling analysis.
the onset of buckling. A simple notch in the beam could
serve as an imperfection to introduce non-linearity. Non-Linear Buckling
Considering an elastic perfectly plastic material is another Analysis:
way to introduce non-linearity
Nonlinear buckling analysis is
a more accurate method which
during analysis linear finite displacement, stresses, loads,
incrementally increases
element analysis does not take and boundary conditions
applied loading until a
the elastic instability of the acquired from this analysis are
structure becomes unstable.
component into consideration fed into a bucking solver, a
This condition of instability is
which is a major reason for means to carry the bucking
indicated by a small increase
bucking of any mechanical analysis. Buckling solver thus
in load level causing a very
component. provides us with different
large change in deflection.
possible buckling failure
Nonlinear buckling analysis is
modes and respective failure
Buckling is often termed as a static method which
safety for each.
potential failure accounts for material and
mechanism which leads to geometric nonlinearities (P-δ
sudden failure of a structural Eigen Value Analysis: and P-∆), load perturbations,
component. Buckling analysis geometric imperfections, and
helps to correctly recognize gaps. Either a small
Eigenvalue buckling analysis
the mechanisms of failure and destabilizing load or an initial
predicts the theoretical
ensure that the design would imperfection is necessary to
buckling strength of a
withstand the expected initiate the desired buckling
structure idealized as elastic.
loading conditions. mode.
In the classic Eigenvalue
Magnitude of buckling loads, Non-Linear Buckling Analysis incrementally increases
material strength and applied loading until a structure becomes unstable. This
component design are the condition of instability is indicated by a small increase in
three main things analyzed by
load level causing a very large change in deflection.
the buckling analysis.
The critical buckling load for
any structure should be method, structural eigenvalues Introducing non linearity in
calculated to know the are computed from the loading the Simulation:
strength of the structure. This and constraint conditions of a
is done by using buckling given system. Each load has When a nonlinear-buckling
analysis to find the buckling an associated buckled mode analysis is run on an idealized
load factor (BLF) value of the shape which represents the structure assuming a perfectly
component. The BLF value of shape a structure assumes round and perfectly straight
the structure is then multiplied when buckled. For real column under a perfectly
by present load value to get structures, imperfections and aligned compressive load,
the critical buckling load of the nonlinear behavior keep theoretically, buckling will
structure. Technically, bucking systems from achieving this never happen, but in practice,
analysis is an extended theoretical buckling strength. buckling may take place
analysis of linear-elastic Since eigenvalue analysis because of imperfections in
"A good objective of leadership is to help those who are doing poorly to do well and to help those who are doing well to do even better." Jim Rohn

22. Non Linear Buckling can be performed by a Load Control
the geometry, loads, and
supports. Method (LCM) or an Arc length Control Method (ACM).
LCM could lead to numerical instabilities and hence it is
easier to use and apply ACM by evenly spacing the points
When real-world imperfections
are absent in the FEA model, on load displacement curve.
buckling will still happen, if
imperfections are introduced the applied load must be The results of the analysis
by discretization errors. multiplied by (or divided, show that in the Linear
Therefore, nonlinear buckling depending on the FEA package buckling, free end figure, the
requires a model with some used) to obtain the buckling- beam buckled in a direction
initial imperfection. When no load magnitude. opposite to the notch and not
such imperfections are toward the side of the notch as
present, they must be added the linear-buckling analysis
to control the onset of The buckling mode displays only predicts the buckled
buckling. We use notch in the the shape, the structure shape and not the direction of
beam as an imperfection to assumes when it buckles in a buckling.
introduce the onset of particular mode, but gives no
buckling. information about the accurate
numerical values of the The Linear buckling, for beam
displacements or stresses. with notch direction relocated
Linear-buckling on the opposite side
analysis of the beam, figure
shows the beam
To illustrate the issues buckling in the correct
involved in the linear and direction, but this is
non-linear buckling, two purely coincidental.
cases are chosen, one Linear buckling beam bending away from notch The color legends with
with a beam fixed at one displacement
end, applied with an axial magnitudes in both
load at the free end and figures point out their
another, beam with a meaninglessness.
fixed and other end with They show that linear
axial load but with prop buckling analysis
Linear buckling beam bending towards notch (same
supports at the free end. cannot provide
case)
One can use any quantitative results
commercial software, like for displacements or stresses.
This is in close analogy to
ANSYS, Solid Works modal analysis, which
Simulation etc to perform this calculates the natural In addition, linear-buckling
analysis. A notch is frequency and provides analysis does not show what
intentionally introduced in the qualitative information on the happens to a structure after
beam to initiate the onset of
the buckling. Linear-buckling Linear Buckling analysis does not show what happens to a
analysis calculates buckling
structure after buckling. Does the structure collapse? Will
load magnitudes that cause
buckling and associated it retain the load-bearing ability in the buckled shape? Or
buckling modes. FEA programs how much will it deform when it buckles?
provide calculations of a large
number of buckling modes and modes of vibration (modal buckling. Does the structure
the associated buckling-load shapes), but not on the actual collapse, or will it retain the
factors (BLF). The BLF is magnitude of displacements. load-bearing ability in the
expressed by a number which buckled shape? How much will
"One of the true tests of leadership is the ability to recognize a problem before it becomes an emergency." Arnold Glasow

23. it deform when it buckles? To are evenly spaced along the To model these events, it is
obtain more information than load-displacement curve, necessary to account for
the BLF and the qualitative which itself is constructed another source of nonlinearity
buckled shape, it is necessary during load application. beside the already considered
to enter the domain of geometric nonlinearity called
nonlinear buckling analysis. yielding. This is done by
Nonlinear analysis calculates using an elastic perfectly
actual displacements and plastic material, the
Nonlinear-buckling analysis stresses. Consider what simplest type of nonlinear
happens in a nonlinear material models.
A load control method of Non- buckling analysis of the
linear analysis is the most notched beam. Note that in
prevalent method of analyzing the figure Nonlinear buckling, However, when the load stays
non-linear cases (Load control free end, the result shows the same, as is most often the
method: The load is applied that buckling takes places in case, the end of the vertical
gradually in multiple steps the right direction and also portion of the curve marks the
rather than in one step as in a close to what the linear- beam’s structural collapse.
linear analysis. Each load buckling analysis predicted. Here, the beam is totally
increment plasticized and
changes can no longer
the support the load.
structure’s If you examined
shape, and the deformed
this, in shape you would
turn, have noted that
changes most of the
the deformation
structure’s Non-Linear buckling beam bending towards notch, predicting stresses & takes place at
stiffness. displacements the support
Therefore, where the plastic
the “hinge” develops.
structure stiffness must be The beam buckles towards the
updated at each increment.) notched side as it should.
Then, the displacement grows Modal & Buckling Analysis:
at an almost constant load. An Analogy.
In Nonlinear-buckling analysis,
the load steps are defined The result implies that the
beam is capable of balancing Linear-buckling analysis is also
either by the user or
the given load acting at an called eigen value buckling or
automatically by the software
increasing load offset, but this Euler buckling analysis
so the difference in
is clearly unrealistic because because it predicts the
displacement between the two
the buckling of the notched theoretical buckling strength of
consecutive steps is not too
beam initiates a chain of an elastic structure. Eigen
large. But implementing the
events leading to structural values are values of load at
load control method in a
collapse as shown in the which buckling takes place.
buckling problem could lead
graphs below. Eigenvectors are buckling
to numerical instabilities due
shapes associated with the
to the fact the onset of the
corresponding eigen values.
buckling results in momentary
According to eigenvalue-
loss of stiffness. Therefore, it
buckling analysis, buckling
is advisable to use the arc
takes place by subtracting the
length control method where
stress stiffness induced by a
the points corresponding to
compressive load from the
consecutive load increments
elastic stiffness. The instability
"Do not follow where the path may lead. Go instead where there is no path and leave a trail." Muriel Strode