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Few people know that Thomas Edison was the inventor of the process of building a precast concrete house

Of all inventions of the inventor Thomas Alva Edison, which is known all over the world, there is an invention that, although not very successful, has an important meaning to the construction industry today, which is precast concrete.

By the end of the 19th century, Edison, like many businessmen and builders at the time, greatly appreciated the performance of cement. Edison believes that cement or precast concrete can be the answer to all housing problems. So he decided to improve and turn cement into an even better material.

Thomas Edison demonstrates a model of a concrete house.

Edison coming to the cement business was a coincidence. For 10 years, Edison failed to crush iron ore and sold all the iron ore waste to cement factories. At the time, Edison tried to maintain the factory’s business using stock from General Electric.

This approach, although quite successful, cannot last long. Edison realized that he was wasting effort in vain. In the end, Edison decided to switch to cement production instead of selling iron ore waste to competitors.

In 1899, Edison founded the Edison Portland Cement Company and built a large-scale factory in western New Jersey, including a huge and almost largest rotary kiln in the world at the time. Within 10 years, Edison and his company became the 5th largest cement manufacturer in the world. Edion’s research team is constantly improving the cement manufacturing process better and Edison holds the patent for those innovations. So far, Edison holds 49 patents related to the cement production process.

His dream is to one day produce a series of cheap concrete houses. He patented a process of building a house with prefabricated concrete blocks instead of pouring one floor at a time. Accordingly, concrete will be poured into large wooden molds for forming. Even outside of walls and floors, he wanted every structure and interior in the house like bathrooms, toilets, sinks, cabinets, beds and even refrigerators and pianos to be made of concrete.

Edison’s patent states: “The goal of my patent is how to build a cement mixed building with a single concrete block molding operation. All parts of It consists of facades, roofs, partitions, bathtubs, floors, … can be made from an inseparable concrete block.

This invention can be applied to any type of building but I plan to use it for housing construction, including stairs, decorative ceilings, furniture, etc. formed by a precast concrete block and attached to the main house. Such a house is certainly very hard to demolish. “

Although Edison’s ambition is considered by many to be crazy. However, to prove to the world that such ambition was possible, he tried to shed two experimental buildings at the home of a gardener and a garage in Glenmont mansion in New Jersey in 1910.

The house is being built with prefabricated concrete blocks.

He even announced that he would donate all of this patent information to architects and construction contractors, regardless of profit.

Edison’s statement then caught the attention of philanthropist Henry Phipps. He also suggested using concrete houses to solve housing problems in the city. New York Phipps even announced it would build a city for working-class families using Edison’s concrete casting technique. However, when building, Edison was unable to provide enough volume as planned.

It was then that Edison realized the unreality of his dream. One of the main technical problems of such one-off houses is the complexity of the molds. Each house needs more than two thousand precast concrete molds and they must be accurately and carefully disassembled to build the next house.

The process is actually quite cumbersome and complicated. Another problem is how to pour concrete the most smoothly. The challenge for the engineers was to create a mixture that was liquid enough to flow into every corner of the mold. But it also needs to be thick enough to condense the aggregate in the cement mixture and not let them settle to the bottom due to gravity.

Despite numerous problems, Edison managed to build a few houses in Union and Montclair, New Jersey, and they still exist today.

Why are the letters on the computer keyboard not in alphabetical order?

About 150 years ago, all papers and letters were handwritten with a pen and ink, and about one or two words had to be put in the ink bottle, making writing very slow and easy to get dirty. .

Then a typewriter was born. The first typewriter was made of metal so it was heavy and had a mechanism that worked a bit like a piano, meaning that when you pressed a key, a lever bounced, causing the hammer at the top to type into the string. and make sounds.


Similarly, at the tip of the typewriter keys are hammers that print the letters. When you press the key with the letter A, the hammer’s hammer heads on the paper and prints the letter A, and the paper inches a little to the left so that the second hammer will type in the space immediately to the right of the A. so you can type a whole word, and if you type a lot, you will get the whole book.

The first typewriter had the same alphabetical order as in the alphabet. The problem is that if you type quickly, two keys side by side are very susceptible, especially if those keys are next to each other. Rearranging the keys reduces the chance that the keys will get stuck.

The American inventor named Christopher Sholes was the most successful when it came to reducing typewriter keys. He tried many arrangements and the best one was similar to the keyboard in the QWERTY order we use today.

Mr. Sholes sold the invention to Remington Company in the US. In the 1870s, the Remington Company produced and sold the first typewriters for commercial purposes. These machines have a QWERTY keyboard.

About 100 years later, so many people typed in the text that it became a professional profession around the world. They use the QWERTY keyboard so familiar that people can hardly change the habit of using the keyboard in a different arrangement.

Besides the QWERTY keyboard, a number of other keyboards were invented and considered easier to learn than the QWERTY keyboard. However, none of them is strong enough to defeat QWERTY.

QWERTY was invented to use the English alphabet. Other languages ​​use other keyboards, such as AZERTY for French, QWERTZ for German, or QZERTY for Italian. You can also see a keyboard used for Indian, Thai, Japanese, Korean or Chinese.

Those who sacrifice for the success of the Apollo program

The Apollo program of putting people on the moon is the result of the efforts and silent sacrifices of hundreds of thousands of people.

July 20, 1969 marked in the history of mankind when the Apollo 11 landed on the Moon. For Neil Armstrong to place the American flag on the surface of the Moon, making the first footprint on it, a well-researched plan, operated by thousands of people. This special program also has many memorable numbers.

Neil Armstrong planted an American flag on the surface of the Moon. (Photo: NASA).

400,000 people support one person
Neil Armstrong is one of NASA’s outstanding pilots. When he landed on the lunar surface on July 20, 1969, the first successful or failed landing all depended on the man’s skill, reaction ability and proficiency. With the gravel fields ahead, the alarm ringing and the fuel running out, Armstrong drove the spacecraft to the ground.

But in a number of conversations and interviews about the landing, Armstrong has always been modest when it comes to this historic achievement. Instead, he emphasized that hundreds of thousands of people contributed to the success of the program.

NASA estimates that a total of 400,000 men and women across the US participate in the Apollo program, from astronauts, flight control specialists, contractors to food suppliers, engineers, and scientists. learn, doctor, nurse, mathematician and programmer.

Flight control specialists follow the journey of Apollo 11.

Viewed from Apollo 11 flight – a flight to help people land on the Moon. Not only did Armstrong receive Buzz Aldrin’s support aboard the ship, there was also a room filled with flight control specialists. In each shift, in addition to the core team of about 20-30 people, there are hundreds of engineers in Houston and experts at Massachusetts Institute of Technology in Boston are on call for advice whenever the computer issues an alarm.

The flight control center is supported by ground communication stations around the world, a team of engineers who make the landing craft at Grumman Group and all subcontractors. Besides, there is a support team from senior managers to coffee sellers, the number has reached thousands. Multiply that number by every other part of the project (rocket, astronaut suit, communications, fuel, design, training, from launching to returning to Earth …). 400,000 people still seem modest. All of these have supported the single man’s action.

Average age of Apollo astronauts: 38
Armstrong was not a specially selected pilot for his first moon landing, his crew was the next option in the rotation. If the Apollo 11 can not land, it is likely that Pete Conrad, commander of the Apollo 12, will be the first man to land on the Moon. In fact, despite representing the entire human race, the Apollo astronauts have the same age, biography, competence, and training.

“In my opinion it is important that we remember how unique and carefully selected the Apollo project team is,” said Teasel Muir-Harmony, who is in charge of displaying the Apollo spacecraft in Bao. Smithsonian National Aerospace Museum in Washington DC, shared. Each member of the Apollo 11 crew was born in 1930, they used to be in the army, were pilots.

At that time Armstrong was 38, the youngest co-commander on the Apollo ship (along with Tom Stafford and Gene Cernan). Charlie Duke, the 36-year-old pilot of the Apollo 16 landing craft, is the youngest man to land on the Moon. The oldest person to walk on the Moon was astronaut Alan Shepard, flying aboard Apollo 14 in 1971. Shepard was 47 years old.

12 astronauts once set foot and drove on the Moon

There are 33 astronauts on flights during the Apollo Moon landing program. Among them, 27 people fly to the Moon, 24 people orbit the Moon but only 12 people set foot on the surface. They represent “humanity” and face the challenge of transmitting that experience to a global audience.

8 NASA astronauts died during the Apollo program
Before the first three crew of the Apollo 7 mission departed in October 1968, eight astronauts on the Apollo program were killed. The first man who died in 1964 was Theodore Freeman when his plane, the T-38 trainer, hit a bird, broke the cockpit cover and the engine stopped working. Despite his escape, Freeman was too close to the ground and died due to the impact.

On February 28, 1966, the main crew for the mission Gemini 9, Elliot See and Charles Bassett prepared to land the T-38 aircraft on St Louis. Due to cloudiness obscuring the runway, See misplaced a turn and crashed into the building where their spacecraft was being built. Two pilots were killed instantly.

In 1967, NASA prepared to launch the first Apollo. But the spacecraft is constantly broken and commander Gus Grissom knows it. In an uncomfortable mood, he hung a lemon outside the Apollo ship simulator in Cape Canaveral base.

On January 27, 1967, the crew, including Grissom, Ed White (the first American to walk in space) and Roger Chaffee, lay in the seats on the launch pad to test the entire spacecraft. The test has failed. Within seconds, flames burned up the crew.

Later that year, Clifton Williams died in another T-38 crash and Edward Givens died in a traffic accident. All eight astronauts and six Soviet astronauts were commemorated with a stele left by the Apollo 15 crew on the Moon.

Only one woman was present in the control room of the Apollo 11 launch
The equipment control specialist, JoAnn Morgan, is the only woman in the control room of the Apollo 11 launch at Cape Canaveral base. As an engineer, a 21-channel guest lady as well as the stability of all Saturn missile tracking systems 5. “Launching is a controlled explosion. You are always a little scared but you still have to watch it, “Morgan said.

As one of the few women in senior positions, Morgan regularly faced gender discrimination, especially when she started the job. “I received obscene calls, some rude comments in the elevator and the touches in the dining area. After a while, most of those actions were gone because people realized I worked really hard. serious, “recounted Morgan.

What is digestion only? Some targets self-consumed in surgery? How long does it take to spend?

Self-draining threads are the only commonly used type of medicine in suturing wounds. There are many types of indigestion, each of which will fit a different type of wound. Today, let us learn about some types of self-consumption targets and how much time will be spent on self-discharge !!!

What is digestion only?

Self-draining threads are mainly made from organic synthetic fibers. After a period of using this thread to suture the mouth of the wound, they will dissolve by performing hydrolysis. There are many types of indigestion that are used during surgery, depending on the characteristics and location of the wounds.

Sew the wound with self-draining thread.

Wounds on the surface of the skin usually use the normal thread to sew and then it will be cut later. This thread trimming can be carried out at home or to health facilities to ensure safety. With wounds in internal organs, cutting is not possible. At this time, people will resort to self-consumption. Wounds that heal long, need a long time for the mouth to heal properly, they will use the type of self-target that has long hydrolysis time.

In surgery, self-consumption is very convenient, because it will reduce the pain that patients suffer.

Some types of digestion time and their respective digestion time
In surgery, a number of commonly used targets are polyglactin 910, polydioxanone, polyglecaprone, simple catgut, chromite catgut, etc. Let’s take a closer look at these threads!

Surgical polyglactin 910 only

Polyglactin 910 will dissolve by hydrolysis.

This thread is synthesized from glycotic, lactic acid, copolymer acid, outside is covered with a layer of polyglactin 370 and calcium stearate. When performing oral sutures of wounds, polyglactin 910 will be softened when penetrating the tissues and limiting tissue irritation, keeping the mouth sutures quite well.

Polyglactin 910 will dissolve by hydrolysis. It takes up to 90 days for this type of thread to be fully absorbed and dissolved by the body.

Self-consumed polydioxanone only

Polydioxanone is synthesized from polimer. This component only surgery has a higher stage, easier to control in the mouth of the wound. Polydioxanone is indicated for tissue-related wounds and tissues that require long term support. Heart-related surgeries, micro-neurosurgery should never use polydioxanone.

Compared to the toughness of this thread, it is so high that it takes up to 90 days for polydioxanone to completely dissolve into the body.

Self-target polyglecaprone only

The ingredients that make up this thread are glycolic acid and caprolactone. Use polyglecaprone for suturing of soft tissues, short support time as well as rapid recovery. This type of thread is easy to use, when performing oral sutures wounds will not cause pain to the patient, the risk of infection is very low.

Like other types of surgery, polyglecaprone will also be self-absorbed, dissolve into the body through hydrolysis. Usually this process lasts for 20 days.

Self-target only simple catgut

Simple catgut is derived from all natural sources when it is made from sheep’s mucus and serum in cow intestines. Their composition contains 97 to 98% of collagen that can be absorbed, twisted or single-stranded, making them extremely durable.

This type of surgery is absorbed very quickly by the body through the enzyme reaction process. Typically, the length of the thread lasts for about 10 days and the thread will completely dissolve within 70 days afterwards. Patients with cancer or malnutrition should consider using this thread because the process of enzyme reactions takes place faster than usual.

Only catgut chromite surgery

This thread is synthesized from the mucus of sheep’s intestines and the serum in cow’s intestines.

Like simple catgut, chromite catgut is also synthesized from the mucus of sheep’s intestines and the serum found in cow intestines. Collagen content accounts for 97 to 98%. However, the difference between these two types is that chromite catgut is treated with chromic salt. This salt works to slow down the reaction of enzymatic decomposition, making the ability to hold stitches better. Types that are only naturally derived will usually increase the ability of tissue to react more than types that are only naturally derived. However, this type of thread is also considered to be very safe in handling surgical incisions.

Chromite catgut is suitable for incisions with short recovery time. Self-sufficiency time is within 14 to 21 days.