Puricare Industrial Enterprises: February 2021

Friday, February 26, 2021

FREE ENERGY DEFINED - Is It Possible and How Would It Work? - Free energy exists, although it’s not free to convert into a form we can use. Renewable energy, much cleaner than energy from fossil fuel, is as close to free energy as things get today, with solar, wind, water and geothermal among the most effective. The beauty of such free energy sources is that they exist in nature. There is no need to mine, ignite, dredge or frack. The key to tapping into these sources is finding ways to convert free energy into a form that meets power needs. A majority of scientists agree that burning fossils fuels contributes to global warming. The resulting climate change helps create more severe weather, such as powerful hurricanes and higher sea levels. And even for those who don’t think climate change is caused in part by humans, there is no doubt that fossil fuel is a finite resource. Oil, natural gas – it’s going to run out, one day. And long before that day, prices for the reduced supply will make gas a niche item bought only by those with a lot of cash. Better alternatives are needed. Here are some of the most used renewable sources. All are provided free by nature. The most amazing source of energy sits at the center of our solar system. The sun generates so much energy that it would take exploding 100 billion tons of dynamite every second to match what it produces. Converting what the sun produces into usable energy is an ongoing process, but more homes use continue to add solar panels.

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Free Energy Defined

Is It Possible and How Would It Work?

by Matthew Speer

Free energy exists, although it’s not free to convert into a form we can use.

Renewable energy, much cleaner than energy from fossil fuel, is as close to free energy as things get today, with solar, wind, water and geothermal among the most effective.

The beauty of such free energy sources is that they exist in nature. There is no need to mine, ignite, dredge or frack.

The key to tapping into these sources is finding ways to convert free energy into a form that meets power needs.

The need for better energy is clear.

A majority of scientists agree that burning fossils fuels contributes to global warming. The resulting climate change helps create more severe weather, such as powerful hurricanes and higher sea levels.

And even for those who don’t think climate change is caused in part by humans, there is no doubt that fossil fuel is a finite resource.

Oil, natural gas – it’s going to run out, one day. And long before that day, prices for the reduced supply will make gas a niche item bought only by those with a lot of cash.

Better alternatives are needed. Here are some of the most used renewable sources. All are provided free by nature.

Solar

The most amazing source of energy sits at the center of our solar system.

The sun generates so much energy that it would take exploding 100 billion tons of dynamite every second to match what it produces.

Converting what the sun produces into usable energy is an ongoing process, but more homes use continue to add solar panels.

And the sun is not expected to run out of energy for about 5 billion years.

Maybe by then, we can know how to tap into the energy from the other 100 billion stars in the Milky Way.

Wind

You may notice entire hillsides covered with wind turbines, especially if you drive through West Texas or parts of California.

Wind is generated by the Earth’s rotation and differences in air pressure.

As with all sources of free energy provided by nature, the trick is in converting the wind’s energy into something that can be used by humans. Wind turbines accomplish that task.

Water

Hydroelectric dams have been in use for decades. They take the energy created by rushing water and convert it into electricity that can be used in homes.

Typically, the dam traps water in a reservoir. When released, the rushing water spins a turbine that activates a generator that produces electricity.

Wave energy is another means of producing power from water. Generators placed on the surface of the ocean are powered by waves that flow through them.

Geothermal

Inside the Earth is a core of geothermal energy. Just consider the power of a volcano, a dramatic example of geothermal matter bursting to the surface.

Power plants on the surface tap into geothermal energy by accessing steam or water reserves inside of the Earth. The resulting heat drives electricity generators.

These are some of the major free, renewable energy sources provided by the Earth itself.

Because they produce energy at lower rates than combusting fossil fuel, using them may require changes in society.

But they certainly help the planet’s overall health and provide much more sustainable energy.

Matthew Speer is a Marketing and Advertising Executive that has worked with companies like AOL and U.S. News University Connection. He also has a passion for sustainability and keeping the Earth a beautiful place for our future generations which is why he helped create iSustainableEarth.com. Inspired by his own family and taking strides to go green he strives to live a sustainable lifestyle through research and action.

http://www.isustainableearth.com/energyefficiency/free-energy-defined-how-it-works

You might also like:

Wind Farms

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2019/08/wind-farms-wind-farms-are-areas-where.html

Solar Energy

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2020/05/solar-energy-solar-energy-is-major.html

Heat From The Earth

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2019/07/heat-from-earth-about-geothermal-energy.html

Hydroelectricity From Waterfalls

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2019/05/hydroelectricity-from-waterfalls-type.html

Environmental Costs of Hydroelectricity

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2018/08/hydroelectricity-hydropower-is-when.html

It’s Time To Switch To Solar

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2021/02/why-its-time-to-switch-to-solar.html

Electric Power Generation

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2019/05/generating-electric-power-key-part-of.html

Dams and Reservoirs

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2019/02/dams-and-reservoirs-dams-are-primarily.html

Thursday, February 25, 2021

ROMAN CONCRETE - Was Roman Concrete Better? - The largest unreinforced concrete dome in world is on the Pantheon. It’s not a modern marvel, but rather an ancient Roman temple built almost two thousand years ago. So, if concrete structures from the western Roman Empire can last for thousands of years, why does modern infrastructure look like this after only a couple of decades? We’ve talked about how concrete’s made, why it often needs reinforcement, and how that reinforcement can sometimes lead to deterioration. Concrete reinforced with steel bars is the foundation of our modern society. The reinforcement is required to give the concrete strength against tensile stress. We use steel as reinforcement because of its strength, its similar thermal behavior, its availability, and low cost. But steel has an important weakness: it rusts. Not only does this corrosion reduce the strength of the reinforcement itself, but its by-product, iron oxide, expands. This expansion creates stresses in the concrete that lead to cracking, spalling, and eventually the complete loss of serviceability - i.e. failure. Corrosion of embedded steel reinforcement is the most common form of concrete deterioration. Romans didn’t put steel in their concrete. One of those clever tricks was just making their structures massive, because the simplest way to keep concrete in compression is to put heavy stuff on top of it, for example, more concrete.

Roman Concrete

Was Roman Concrete Better?

Grady Hillhouse

The largest unreinforced concrete dome in world is on the Pantheon.

It’s not a modern marvel, but rather an ancient Roman temple built almost two thousand years ago.

So, if concrete structures from the western Roman Empire can last for thousands of years, why does modern infrastructure look like this after only a couple of decades?

Hey I’m Grady and this is Practical Engineering. In today’s episode, we’re taking a look at the factors that affect the design life of concrete.

If you haven’t seen the previous videos in this series about concrete, here’s a quick synopsis.

We’ve talked about how concrete’s made, why it often needs reinforcement, and how that reinforcement can sometimes lead to deterioration.

Concrete reinforced with steel bars is the foundation of our modern society. The reinforcement is required to give the concrete strength against tensile stress.

We use steel as reinforcement because of its strength, its similar thermal behavior, its availability, and low cost.

But steel has an important weakness: it rusts. Not only does this corrosion reduce the strength of the reinforcement itself, but its by-product, iron oxide, expands.

This expansion creates stresses in the concrete that lead to cracking, spalling, and eventually the complete loss of serviceability - i.e. failure.

In fact, corrosion of embedded steel reinforcement is the most common form of concrete deterioration. But it hasn’t always been that way.

The Romans got around this problem in a very clever way: they didn’t put steel in their concrete.

Simple enough, right? They harnessed the power of a few clever structural engineering tricks like the arch and the dome to make sure sure that their concrete was always resisting compression and never tension, minimizing the need for reinforcement.

One of those clever tricks was just making their structures massive, and I mean that literally, because the simplest way to keep concrete in compression is to put heavy stuff on top of it, for example, more concrete.

We use this trick in the modern age as well. Most large concrete dams are gravity or arch structures that rely on their own weight and geometry for stability.

In both gravity and arch dams, the shape of the structures are carefully designed to withstand the water pressure using their own weight.

You can see how they get larger, the deeper you go.

So, even with the tremendous pressure of the water behind the structure, there are no tensile stresses in the concrete, and thus no need for reinforcement.

But lack of steel reinforcement isn’t the potential only reason Roman concrete structures have lasted for so long.

One of the other commonly-cited suggestions for the supremacy of Roman concrete is its chemistry.

Maybe they just had a better recipe for their concrete that somehow got lost over time, and now those of us in the modern era are fated to live with substandard infrastructure.

In fact, in 2017, scientists found that indeed the combination of seawater and volcanic ash used in ancient roman concrete structures can create extremely durable minerals that aren’t normally found in modern concrete.

But that’s not to say that we can’t make resilient concrete in this modern age. In fact, the science of concrete recipes, also known as mix design, has advanced to levels a Roman engineer could only dream of.

One of most basic, but also most important factors in concrete’s chemistry is the ratio of water to cement.

I did an experiment in a previous video that showed how concrete’s strength goes down as you add more water.

Extra water dilutes the cement paste in the mix and weakens the concrete as it cures. The Romans knew about the importance of this water to cement ratio.

In historical manuscripts, Roman architects described their process of mixing concrete to have as little water as possible, then pounding it into place using special tamping tools.

Interestingly enough, we have a modern process that closely mimics that of the ancient Romans.

Roller Compacted Concrete uses similar ingredients to conventional concrete, but with much less water, creating a very dry mix.

Rather than flowing into place like a liquid, RCC is handled using earth moving equipment, then compacted into place using vibratory rollers like pavement.

RCC mixes also usually include ash, another similarity to Roman concrete. It’s a very common construction material for large gravity and arch dams because of its high strength and low cost.

Again, these are usually unreinforced structures that rely on their weight and geometry for strength.

But, not everything can be so massive that it doesn’t experience any tensile stress.

Modern structures like highway overpasses and skyscrapers would be impossible without reinforced concrete.

So, generally we like our concrete to be more viscous or soupy. It’s easier to work with. It flows through pumps and into the complex formwork and around the reinforcement so much more easily.

So, one way we get around this water content problem in the modern age is through chemical admixtures, special substances that can be added to a concrete mix to affect its properties.

Water reducing admixtures, sometimes called superplasticizers, decrease the viscosity of the concrete mix. This allows concrete to remain workable with much lower water content, avoiding dilution of the cement so that the concrete can cure much stronger.

I mixed up three batches of concrete to demonstrate how this works.

In this first one, I’m using the recommended amount of water for a standard mix. Notice how the concrete flows nicely into the mold without the need for much agitation or compaction.

After a week of curing, I put the sample under the hydraulic press to see how much pressure it can withstand before breaking.

This is a fairly standard test for concrete strength, but I’m not running a testing lab in my garage so take these numbers with a grain of salt.

The sample breaks at around 2000 psi or 14 MPa, a relatively average compressive strength for 7-day-old concrete.

For the next batch, I added a lot less water. You can see that this mix is much less workable. It doesn’t flow at all. It takes a lot of work to compact it into the mold.

However, after a week of curing, the sample is much stronger than the first mix. It didn’t break until I had almost maxed out my press at 3000 psi or 21 MPa.

For this final batch, I used the exact same amount of water as the previous mix. You can see that it doesn’t flow at all.

It would be impossible to use this in any complicated formwork or around reinforcement.

But watch what happens when I add the superplasticizer. Just a tiny amount of this powder is all it takes, and all of a sudden, the concrete flows easily in my hand.

In many cases, you can get a workable concrete mix with 25% less water using chemical admixtures.

But most importantly, under the press, this sample held just as much force as batch 2 despite being just as viscous as batch 1.

The miracle of modern chemistry has given us a wide variety of admixtures like superplasticizers to improve the characteristics of concrete beyond a Roman engineer’s wildest dreams.

So why does it seem that our concrete doesn’t last nearly as long as it should. It’s a complicated question, but one answer is economics.

There’s a famous quote that says “Anyone can design a bridge that stands. It takes an engineer to build one that barely stands.”

Just like the sculptors job is to chip away all the parts of the marble that don’t look like the subject, a structural engineer’s job is to take away all the extraneous parts of a structure that aren’t necessary to meet the design requirements.

And, lifespan is just one of the many criteria engineers must consider when designing concrete structures.

Most infrastructure is paid for by taxes, and the cost of building to Roman standards is rarely impossible, but often beyond what the public would consider reasonable.

But, as we discussed, the technology of concrete continues to advance. Maybe today’s concrete will outlast that of the Romans.

We’ll have to wait 2000 years before we know for sure. Thank you for watching, and let me know what you think!

https://youtu.be/qL0BB2PRY7k

Hey, I’m Grady Hillhouse and this is Practical Engineering! I am a husband, a professional civil engineer, and educational video producer in San Antonio, Texas.

Randall Munroe said, "You can look at practically any part of anything manmade around you and think, 'Some engineer was frustrated while designing this.' It's a little human connection." My goal for Practical Engineering is simple: to increase exposure and interest in the field of engineering.

Of course, as a civil engineer, much of my content is geared towards infrastructure and the stories behind the humanmade world we live in. I like to help people make a connection between themselves and their constructed environment. In order for people to care about infrastructure, they need to be interested in the engineering behind it and see people who are passionate about finding innovative ways to meet humanity’s basic needs. I really believe this and it’s important to me. I hope that my videos are helpful to you and encourage you to take opportunities to be an advocate for civil engineering.

https://practical.engineering/blog/2019/3/9/was-roman-concrete-better

You might also like:

Roman
Concrete

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2020/01/roman-concrete-how-volcanic-material.html

Roman Engineering Tricks

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2018/09/roman-engineering-tricks-romes.html

Cement and
Concrete

CLICK HERE . . . to view . . .

https://puricarechronicles.blogspot.com/2017/12/cement-and-concrete-many-people-talk.html

Water supply system

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2019/12/water-supply-system-water-was-important.html

Volcanic Ash

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2019/11/volcanic-ash-term-is-used-for-material.html

History of drinking water treatment

CLICK HERE . . . to view . . .

https://puricare.blogspot.com/2016/10/water-treatment-history-romans-built.html

Tuesday, February 23, 2021

TIDES - Tides are another kind of wave motion in the ocean. Tides are a change in the ocean water level, typically reaching a high and low level twice a day usually occurring about six hours apart. The term for the change from low to high tide is called the "flood tide". The change from high tide to low tide is called the "ebb tide". Tides result from the pull of gravity; on the earth alone, between the earth and moon and between the earth and the sun. The gravitational pull of the sun on the earth is about 178 times stronger than the gravitational pull on the earth from the moon. However, because of the close proximity of the moon, when compared to the sun, the tidal pull by the moon is over twice that of the sun. The result of this tidal pull is a bulge in the ocean water almost in line with the position of the moon; one bulge toward the moon and one on the opposite side of the earth, away from the moon. When we observe the tides what we are actually seeing is the result of the earth rotating under this bulge. It is easy to understand why there should be a bulge of water, producing a high tide, on the side of the earth facing of the moon. But why is there a bulge on the opposite side as well? It is obviously not gravity that is doing it but rather, it is the difference in gravitational force across the earth that causes the bulge. This difference in gravitational force comes from the moon's pull at various points on the earth.

Tides

JetStream, the National Weather Service Online Weather School

Tides are another kind of wave motion in the ocean.

Tides are a change in the ocean water level, typically reaching a high and low level twice a day usually occurring about six hours apart.

The term for the change from low to high tide is called the "flood tide".

The change from high tide to low tide is called the "ebb tide".

Tides result from the pull of gravity; on the earth alone, between the earth and moon and between the earth and the sun.

The gravitational pull of the sun on the earth is about 178 times stronger than the gravitational pull on the earth from the moon.

However, because of the close proximity of the moon, when compared to the sun, the tidal pull by the moon is over twice that of the sun.

The result of this tidal pull is a bulge in the ocean water almost in line with the position of the moon; one bulge toward the moon and one on the opposite side of the earth, away from the moon.

When we observe the tides what we are actually seeing is the result of the earth rotating under this bulge.

It is easy to understand why there should be a bulge of water, producing a high tide, on the side of the earth facing of the moon. But why is there a bulge on the opposite side as well?

It is obviously not gravity that is doing it but rather, it is the difference in gravitational force across the earth that causes the bulge. This difference in gravitational force comes from the moon's pull at various points on the earth.

Because the pull of gravity becomes stronger as the distance decreases between to object, the moon pulls a little harder at point "C" (closest point to the moon) than it does at point "O" (in the center of the earth), and the pull is weaker still at point "F" (farthest point from the moon).

Figure 2

If it were not for the earth's gravity, the planet would be pulled apart (figure 2).

Yet also because of the earth's gravity which pulls us toward the center of the planet we can, mathematically subtract the moon's pull at the center of the earth from the moon's pull at both point "C" and "F".

Figure 3

When this vector-based subtraction occurs, we are left with two smaller forces; one toward the moon and one on the opposite side point away from the moon (figure 3) producing two bulges.

As the earth makes one rotation in 24 hours, we pass under these areas where the tidal force pulls water away from the earth's surface and experience high tides.

Also, since the difference in gravitation force is constant across the earth, the bulge on both side of the earth is essentially the same.

Which explains why consecutive high tides are nearly the same height each time regardless whether the moon is overhead or on the opposite side of the earth.

The change in the water level with the daily tides from location to location results from many factors.

The oceans and shorelines have complex shapes and the depth, and configuration, of the sea floor varies considerably.

As a result, some locations only experience one high and low tide each day, called a diurnal tide.

Other locations experience two high and low tides daily, called a semi-diurnal tide.

Still, other sites have mixed tides, where the difference in successive high-water and low-water marks differ appreciably.

Another factor in the variation of tides is based on the orbit of the moon around the earth and the earth around the sun. Both orbits are not circles but ellipses.

The distance between the earth and moon can vary by up to 13,000 miles (31,000 km).

Since the tidal force increase with decreasing distance then tides will be higher than normal when the moon is at its closest point (called perigee) to the earth, approximately every 28 days.

Likewise, the earth's elliptical orbit also causes variations in the sun's pull on the tides as we move from the closest point to the farthest point (called apogee) over the course of a year.

And just to complicate things even more, the moon's orbit is inclined 5° to the earth's rotation.

So, the north/south orientations of the bulge also varies between the northern and southern hemisphere over this same 28-day orbital period.

Earth-Moon-Sun configuration for Spring tide

As the moon completes one orbit around the earth (about every 28 days), there are two times in each orbit when the earth, moon and sun are in line with each other and two times when the earth, moon and sun are at right angles.

When all three are in line (around full and new moons), the combined effect of the moon's and sun's pull on the earth's water is at its greatest resulting in the greatest ranges between high and low tide.

This called a "spring" tide (from the water springing or rising up).

Seven days after either full or new moon, the earth, moon and sun are at right angles to each other.

Earth-Moon-Sun configuration for Neap tide

At this time the pull of the moon and the pull of the sun partially cancel each other out. The resulting tide, called a "neap" tide, has the smallest range between high and low tide.

This graph indicates how the ocean level changes in height daily for May 2019 in Santa Barbara, CA. For this location there are two high and low tides daily with one ebb and flow greater than the other.

Example of the daily tide and differences between Spring and Neap tides at Santa Barbara, CA from May 2019.

The difference in sea-level height between each high and low tide changes daily depending upon the position of the Moon.

The greatest difference in height occurs around new and full moons; 6.27 ft. (1.91 m) and 7.18 ft. (2.19 m) respectively.

The least difference in height occurs at both first- and last-quarter moon phases; 4.72 ft. (1.44 m) and 3.16 ft. (0.96 m) respectively.

Local influences effect the actual timing of spring and neap tides and therefore they may not necessarily align precisely with the phases of the moon.

Also, this graph represents this location for this month and year only. High and low tides, and their timing, for every location world-wide are different day-by-day, month-by-month, and year-by-year.

Welcome to JetStream, the National Weather Service Online Weather School. This site is designed to help educators, emergency managers, or anyone interested in learning about weather and weather safety.

https://www.weather.gov/jetstream/tides

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