History of ovens


Thanks to our ancestors for developing the oven due to which we are today able to eat bread,pies,buns,pizza and all that. Modern ovens are far more advanced than ever thought. Their temperature can be easily controlled and they do not produce smoke.We think that oven is a simple household machine but it has a great story behind its existence.

Ovens are basically an insulated structure in which heat is regulated and it is used for cooking purpose.
Earliest ovens were in the form of pits in ground in central Europe around 29,000 B.C.

Ovens were also used by cultures of Indus valley and pre-dynestic Egypt. 
Greeks created variety of doughs,loaf shapes,and style of serving bread with other foods.

The technology of ovens advanced over the years from just pits in the earth to microwave ovens. 

Following the Medivial period ovens underwent many changes over time from wood, iron, coal, gas, and even electric. The wood burning stoves saw improvement through the addition of fire chambers that allowed better containment and release of smoke. 
Another recognizable oven would be the cast-iron stove. These were first used around the early 1700s .
At the end of 18th century coal ovens were developed which were more efficient.

In 19th century gas and electric ovens were used which were easy to control and made baking better. The gas ovens were invented in 1820s and electric ovens came in late 19th century. Due to unavailability of gas to many households of the world it was not popular in many countries but in Europe it was used as gas was available there to households same condition was with electric ovens.

The microwave oven was invented by Percy Spencer in 1946. It uses microwaves to excite water molecules to produce heat .

  

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Origin of water on the Earth.

Our Earth the blue planet . The reason for it’s beauty is water which covers 71% of its surface . But from where did the water came from which fills the oceans of Earth?Many of the hypothesises have been given to explain origin of earth’s water , although none of them is clearly accepted.

 The Possible Source for origin of earth’s water can be – Extraplanetary sources  Or   internal sources.
Extraplanetary sources


The water may have come from the outer reaches of asteroid belt. Celestial bodies such as comets, water-rich- meteoroids(proto planets) may have collided to the Earth significantly over the years to fill oceans of earth. Previous measurement of the hydrogen isotopes’ concentrations in comets and trans-Neptunian objects correspond only slightly to water on Earth. 

Measurements of the isotope ratios of deuterium to protium (D/H ratio) in the four comets Halley, Hyakutake, Hale-Bopp , and 67P/Churyumov–Gerasimenko, by researchers such as David Jewitt, is approximately double that of oceanic water.

So comets and trans-Neptunian objects must haven’t brought lots of water on earth.

Measurements of the ratio of the hydrogen isotopes deuterium and protium point to asteroids, since similar percentage impurities in carbon-rich chondrites were found in oceanic water.

 

 Now the studies have shown that water with similar deuterium-to-hydrogen ratio was already available at the time of Earth’s formation, as evidenced in ancient “eucrites” meteorites originating from the asteroid Vesta. 

According to Alessandro Morbidelli, the largest part of today’s water comes from protoplanets formed in the outer asteroid belt as the D/H proportions of water in carbon-rich chondrites point to a similar D/H ratio as oceanic water. Nevertheless, mechanisms have been proposed which suggest D/H-ratio of oceanic water may have increased significantly throughout Earth’s history. Such a proposal is consistent with the possibility that a significant amount of the water on Earth was already present during the planet’s early evolution.

Measurements of the chemical composition of Moon rocks suggest that Earth was born with its water already present. Investigating lunar samples carried to Earth by the Apollo 15 and 17 missions found a deuterium-to-hydrogen ratio that matched the isotopic ratio in carbonaceous chondrites. The ratio is also similar to that found in water on Earth. The findings suggest a common source of water for both objects. This supports a theory that Jupiter temporarily migrated into the inner Solar System, destabilizing the orbits of water-rich carbonaceous chondrites. As a result, some of the bodies could have fallen inwards and become part of the raw material for making Earth and its neighbors. The discovery of water vapor out-gassing from Ceres provides related information on water-ice content of the asteroid belt.

Internal sources

Gradual “dehydration melting” — leakage of water stored in hydrate
minerals of Earth’s rocks — could have formed a portion of its water. 

Water may also have come from volcanism: water vapor in the atmosphere that originated in volcanic eruptions may have condensed to form rain, slowly filling Earth’s oceanic basins. 
A sizeable quantity of water would have been in the material that formed Earth. Water molecules would have escaped Earth’s gravity more easily when it was less massive during its formation. Hydrogen and helium are expected to leak from the atmosphere continually, but the lack of denser noble gases in the modern atmosphere suggests that something disastrous happened to the early atmosphere.

Part of the young planet is theorized to have been disrupted by the impact which created the Moon, which should have caused melting of one or two large areas. Present composition does not match complete melting and it is hard to melt and mix huge rock masses completely. However, a fair fraction of material should have been vaporized by this impact, creating a rock-vapor atmosphere around the young planet. The rock-vapor would have condensed within two thousand years, leaving behind hot volatiles which probably resulted in a heavy

carbon dioxide atmosphere with hydrogen and water vapor. Liquid water oceans existed despite the surface temperature of 230°C because of the atmospheric pressure of the heavy CO2 atmosphere. As cooling continued, subduction and dissolving in ocean water removed most CO2 from the atmosphere but levels oscillated wildly as new surface and mantle cycles appeared. 

Study of zircons has found that liquid water must have existed as long ago as 4.404 ± 0.008 Ga , very soon after the formation of Earth. [17][18][19][20] This requires the presence of an atmosphere. The Cool Early Earth theory covers a range from about 4.4 Ga to 4.0 Ga.

In fact, recent studies of zircons (in the fall of 2008) found in Australian Hadean rock hold minerals that point to the existence of plate tectonics as early as 4 billion years ago. If this holds true, the previous beliefs about the Hadean period are far from correct. That is, rather than a hot, molten surface and atmosphere full of carbon dioxide, Earth’s surface would be very much like it is today. The action of plate tectonics traps vast amounts of carbon dioxide, thereby eliminating greenhouse effects, and leading to a much cooler surface temperature, and the formation of solid rock, and possibly even life. 

Role of organisms

Some terrestrial water may have had a biochemical origin, during the Great Oxygenation Event , via redox reactions and photosynthesis . 

In the early 1930s, Cornelis Van Niel discovered that sulfide-dependent chemoautotrophic bacteria ( purple sulfur bacteria ) fix carbon and synthesize water as a byproduct of a photosynthetic pathway using

hydrogen sulfide and carbon dioxide: 

CO2 + 2H 2S → CH 2O + H 2O + 2S

Few modern organisms use this method of photosynthesis, making their water contribution negligible. But on the hydrogen-sulfide-rich and oxygen-poor early Earth, a small but significant portion of Earth’s water may have been synthesized biochemically through this pathway. 

                    CC BY-SA 3.0

Sustainable Education for aHealthier Future

By Ogadi mma Mbadiwe

Education gives knowledge
which as Bacon rightly puts,
is a “source of power to man”.
However, it is crucial we note
that this power can function
either as one employed to
build a better future or as
one that destroys.

Our
masters, the likes of Galileo,
after much philosophizing and
experimentation, discovered
truths and initiated
beneficial principles now
observed in our educational
system. Their great
philosophies are perfect for
numerous situations, but our
system does not show scholars
the path to think and
understand the proper
situations to apply them. This
is chiefly because the
concentration of teachings
nowadays is not to make people
think, which ought to be the
primary goal, but chiefly to
uphold existing laws,
reasoning in the confinement
of principles, and empowering
indirectly an unsustainable
world.

Acquiring
Knowledge of established
principles is good. But our
educational system is leaving
out an essential goal of
growing our thinking faculty,
by not grounding scholars with
the understanding that the
established principles are
simply discoveries employed to
help and should not be taken
as final. Such limits our
sense of discovery needed to
address the diverse problems
growing in our world.Time or situation can
transform valid principles to
invalid; the superseded
scientific laws or theories we
had and will still have are
examples. “To be yourself in a
world that is constantly
trying to make you something
else is the greatest
accomplishment” (Ralph Waldo).
A good quote it is; however,
students are not grounded to
understand its context and
scope: Sadly, one can now see
a sadist employing similar
quote to justify actions,
causing mayhem.

At a
tender age, it was like a law
according to my parents and
remarks from people that rain
starts and ends in certain
months. I remember asking:
“What if it rains in January?”
their answer was: “It cannot”.
The reply came with some air
of finality because the
principle had been valid
historically and probably
because they had never
experienced otherwise. The
principle was true. To them it
was irrevocable. But time has
invalidated that principle
through climate change. Now
the months they had known to
bring heavy downpours
sometimes turn to be the
driest.

Life gets more
complex every day, luckily we
have principles intended to
help, not to mold or limit our
future. Sadly, our recognized
principles cannot fit in every
situation, and sticking on
them will only bring about
chaos. For a sustainable
world, we need a kind of
education where principles are
acknowledged as a stimulus and
not a decree. We need
Education where people have
enough grounds to express
themselves beyond established
principles, laws or
philosophies; one that
develops our reasoning and
thinking faculty without
constraints.

Pitiably,
the knowledge we now gain from
education does not train one
in the part of wisdom which
grows when one begins to
think. It only exposes some
people’s wise thoughts or
principles. Our system of
education now yields educated
fanatics: people that have
acquired better knowledge on
how to present and manage
their fanaticism, planting
chaos by training advanced
erroneous people.

Due to
life’s growing complexities,
education that develops our
discerning ability to avoid
further knowledge
misappropriation is needed.
Adoption of fine principles
helps, but we should avoid
settling in a period where
�scholars are chiefly
concerned with following of
principles, so we can elude a
future of people that reason
more with citations than their
heads, like robots.

For
a peaceful and sustainable
future, we should stop the
degrading practice of
following principles
thoughtlessly in our
educational system, and
welcome fresh educational
scheme that stimulates our
thinking faculty. That will
enable all to understand the
fact that time or situation
can change anything. So, one
would not be quick to conclude
because of knowledge from
recognized scholars or
universal principles.

I
believe in the future of
education where people do not
just copy principles or laws,
but where people also
philosophize on situations to
know where the principles are
usable. This will free our
world from the problematic
chains of principles. Some of
our masters foresaw this ugly
future of ‘scholaroids’;
Socrates addressed it: “I
cannot teach anybody anything,
I can only make them think.”

Article Source: http://
EzineArticles.com/expert/
Ogadimma_Mbadiwe/1879612

http://
EzineArticles.com/?Sustainable-
Education-for-a-Healthier-
Future&id=9698205

7 Ways to Increase Traffic Using Social Media

By Renee Barnes-Orozco

Social media is huge and
growing. There are groups,
fanpages, company pages and
your own personal page that
you can use to engage with
your target audience. The
following 7 tricks, tips and
techniques have been proven to
increase the amount of traffic
you get from large social
sites and more: Facebook,
Pinterest, Twitter, Instagram,
Tumblr, LinkedIn and other
social media sites are just a
few of the popular sites and
should be considered when
producing material for
publication.

1 –
Automate the Process

Automated social media
engagement is possible through
free websites like Buffer
(free and paid), HootSuite
(free and paid) and IFTTT.
They put your marketing on
autopilot, and when you are
consistently in the face of
your audience, your traffic
tends to improve. There are
other paid software options
that you can use to expand
your reach that you may or may
not find of benefit.

2 – Ask for the Share,
Like, Retweet

Give
your followers a call to
action. If someone enjoys some
content you share on Facebook
or Twitter, etc, they will be
very receptive to sharing that
content. Tell them exactly
what to do, and you enjoy a
greater possibility of
improved traffic from Shares,
Likes, Retweets, Repins, etc.
This has been known to expand
your reach to people you might
not be able to reach
otherwise.

3 – Make
Social Media Sharing Simple

If you have a blog or
website should provide a
simple means of sharing your
content. This means adding
social media sharing buttons
and plug-ins to all of your
web properties, guaranteeing
it is simple and quick for
your readers to spread the
word when they find a post of
benefit or interest.

4 – Fill Out Your
Profiles Completely

This may seem like common
sense. However, many online
business owners and
entrepreneurs have incomplete
social media profiles.
Wherever you have the chance,
tell people about yourself and
your business, providing
plenty of links back to your
website or blog. Look in the
profile or other setting
section of the social site to
go into more detail of who,
what, when, where, etc. People
do look at it if they are
interested. Take your business
seriously.

5 – Run a
Contest or Giveaway

KingSumo is one of many
companies that will help you
create and manage a successful
giveaway or contest on social
media websites. This single
traffic driving strategy can
result in significantly higher
numbers of visitors to your
site. Polls can sometimes help
in a similar fashion.

6 – Be Creative And
Share Again The Same Message/
Article/Other Content!

Just because you share a
blog post or new piece of
content on Facebook doesn’t
mean you can’t share it again
later. Your prospects and
followers on social media are
not always logged in at the
same time. This means that
your content should be shared
on all of the social media
websites multiple times. Do it
in such a way that it does not
look exactly the same on your
social media timeline. You can
use a different picture, text
only, and be sure to add other
business related posts in
between your duplicate posts.
I have visited pages where the
same post shows up 5 times in
a row and it does not look
good. Tends to make me think
the poster is not creative and
makes me not to want to do
business with them.

7
– Be Everywhere, and Be
Consistent

Sign up
for all of the largest social
media sites, and those most
relevant to your niche or
market. Be everywhere, instead
of just concentrating on
Facebook and Twitter. There
are other sites that might get
you more eyeballs to your
content because there might
not be as much competition for
your market.

Remember to
be consistent with your
engagement and content. There
are a lot of competitors out
there, so you need prospects
and followers to see you
regularly providing
information and engagement.

Again, be
consistent and prolific in
putting out your content.

As someone told me once –

If you are not
putting your content out there
to be seen, you and your
business do not exist!

Think about it.

This excellent training
system includes tools to use
for multiple streams of income
has helped many people who
have never made money online
make their first money online
ever! There are also great
social media tips and
strategies covered from the
owner as well as actual
members themselves! Go check
it out here – http://
empowerelite.net
You will
see some free training and
have a chance to become a
member so that you too can
earn money online with more
ease and understanding of how
to approach your business..

Article Source: http://
EzineArticles.com/expert/
Renee_Barnes-Orozco/492837

http://
EzineArticles.com/?7-Ways-to-
Increase-Traffic-Using-Social-
Media&id=9730377