A sad tale to TEL

You may have heard an elder asking for unleaded petrol at a pump. Do you know why lead was once added to petrol? And why it was discontinued later?

The problem of ‘knocking’ in engines
In the early days of automobiles, ‘knocking’ was a major problem. In a car’s engine, the petrol is injected into a ‘fuel chamber’, where it mixes with air. A spark plug then creates an electric spark, which causes the fuel-air mixture to burn and produce heat. This causes the air to expand and push a piston, which drives the wheel.

However, one problem was that the fuel would catch fire even when the spark was not provided. This often led to engine problems; sometimes it even exploded!

The search for an anti-knock
Many people tried to find a solution. One way was to find a chemical that could be added to petrol, so that it would not combust until the spark was provided. In 1921, Thomas Midgley discovered that a compound called tetra-ethyl lead (TEL) prevented knocking when added to fuel. Midgley is also famous as the discoverer of CFCs.

TEL was soon adopted by fuel companies around the world as an additive to fuels. However, it soon proved to be one of the world’s biggest chemical disasters.

TEL and Lead poisoning
Lead is very dangerous to human beings. It causes anaemia, memory loss, abdominal pain, bone weakening, depression and finally death. It can be identified by ‘lead hue’, i.e. pale colouration of the skin. As the use of TEL spread around the world, it led to lead poisoning among petrol pump workers as well as users.

Lead also poisons the ‘catalytic converters’ that all modern car engines must be fitted with. This is a small device that removes dangerous substances like carbon monoxide and nitrogen oxides. However, even tiny amounts of lead can damage the converter.

Sadly, TEL continued to be used for a very long time as there was no other alternative available. However, many improvements were made to engine design over the years, reducing or eliminating ‘knocking’. With the need for leaded fuel slowly decreased. Lead poisoning causes anaemia, memory loss, abdominal pain, bone weakening, depression and finally death.

A lesson learnt
TEL
has since been banned in many countries around the world. India banned the use of it in 2000. Alongside, the government introduced rules called the Bharat Stage standards. These rules require car manufacturers to implement technologies that reduce or eliminate the need for unleaded fuels.

The story of TEL highlights the nature of chemistry. What seems like a reasonable solution to a problem can unfortunately create terrible problems. Luckily, scientists today have adopted many methods to make science safer. In chemistry, such methods are called Green Chemistry.

Facts About Plasma

Like fish in the ocean, we humans too, live in a giant ocean. We spend all our lives in a gigantic ocean of plasma, but we’re barely aware what it is! Physicist Max Babi explains all about plasma – the fourth state of matter.

Just what is plasma?
‘Plasma’ is a Greek word meaning ‘that which is diffuse’ i.e. unclear, or semi-
transparent. It is also defined by physicists as ‘ionized matter’. This is the plasma of physics. Don’t confuse it with ‘biological plasma’ which is a colourless jellylike liquid in our blood.

All matter is composed of atoms which are ‘neutral’. That means they do not carry any electrical charge. Sometimes a flash of high voltage, or heating to extreme temperature will cause the ‘outermost’ electrons to get knocked off. These electrons will then knock off electrons from neighbouring atoms. This creates a mass of ionized matter, which is called plasma. Plasma is considered the 4th state of matter.

The other three states of matter are solids, liquids and gases, all of which are neutral in normal conditions. The plasma state is similar to the gaseous state, and yet it is very different. How?

Gases are electrically neutral, but plasmas contain both positive and negative charges. Gases cannot conduct electricity, plasmas can. Gases are not influenced by electromagnetic fields; plasmas can be deflected, focused or diverged by such fields.

The uses of plasmas
Micro-plasma welding is a method used to join paper thin sheets of metals. The
joint becomes invisible after polishing. Stainless steel water storage tanks and other kitchen implements are made this way.

Plasma spray process is a most magical use of thermal plasmas it is the only coating process that can apply any material on to any material.

Non-metal on to non-metal: Teflon on to magnesia (ceramic, also called as Magnesium oxide). Some chemicals like hydrofluoric acid can corrode the ceramic vessels they are kept in; coating them with Teflon prevents corrosion.

Metal on to metal: Titanium on to mild steel, to prevent corrosion of steel.
Non-metal on to metal: alumina on to stainless steel. Alumina reduces the wear and
tear on the stainless steel vessel due to industrial processes.

Metal on to non-metal: copper on to porcelain used in capacitors. Plasma-spraying copper onto the porcelain makes it ‘solderable’, so that electric wires can be attached to it.

Lithium:The Oil Of The 21st Century

Today, most of our vehicles and electric power plants run on fuels that come from petroleum. The supply of these fuels will end a few decades from now. So what would power our cars and homes? The answer may be lithium.

Oil in the 20th century
Let’s understand the role of oil better in our times. In 1885, Gottlieb Daimler & Wilhelm Maybach invented a car engine that ran efficiently on petrol. This made it cheaper to own and use cars. Soon people around the world were buying cars, trucks. Diesel-run buses and trains ferried thousands of people across hundreds of kilometres. Since everyone needed petrol and diesel, drilling oil wells and extracting petrol became a very big business, employing millions of people. Today, there is no country that can do without oil.

An electronic world
But oil is a limited resource, and it also contributes to global climate change. Hence, countries are looking for other means to produce electricity and run vehicles, which are cheap, eco-friendly and plentiful. Sunlight is one of them, wind another. Hydrogen can be used as a fuel to make electricity. But a new source of energy scientists are thinking of is lithium.

It is already used in lithium ion batteries, the kind that powers your laptops and mobile phones. These batteries are rechargeable, so even a small amount of lithium will go a long way. In the future, you may be driving electric cars powered by lithium ion batteries. The chemical also has special uses in nuclear power plants. As we add more electronic devices in our lives, and reduce oil-burning ones, we’re going to need hundreds of tonnes of it every year.

Getting rich with lithium
In the 20th century, countries that produced oil, like Saudi Arabia, UAE and Russia became very rich, as other countries depended on them for supplies. Similarly, China is getting rich by supplying rare earth minerals to many countries. So in the coming century, countries that have big deposits of lithium can hope to get rich too.

Bolivia holds about half of the world’s potential its supply. Next come Chile, Argentina and China. The Bolivian government has signed deals with countries including Japan, Korea and France to mine and export lithium. It plans to use this money to build hospitals, schools and battery-making factories, helping many millions of Bolivians escape poverty, malnutrition and ill-health. A big source of the metal has also been found in Afghanistan.

And we hope that this year – the international year of chemistry – we’ll come to know of more sources of this important element!

How do smoke detectors work?

As the saying goes, “Where there’s smoke, there’s fire.” Smoke detectors are amazing: They’re pretty inexpensive, but they save thousands of lives each year. All smoke detectors consist of two basic parts: a sensor to sense the smoke and a very loud electronic horn to wake people up. Smoke detectors can run off of a 9-volt battery or 120-volt house current. There are two most common types of smoke detectors used today: photoelectric detectors and ionization detectors.

Photoelectric Detectors
You may have noticed sometimes when you walk into a mall or store , a bell goes off as you cross the threshold. If you look, you will often notice that a photo beam detector is being used. Near the door on one side of the store is a light (either a white light and a lens or a low-power laser), and on the other side is a photodetector that can “see” the light.

When you cross the beam of light, you block it. The photodetector senses the lack of light and triggers a bell. You can imagine how this same type of sensor could act as a smoke detector. If it ever got smoky enough in the store to block the light beam sufficiently, the bell would go off. But there are two problems here:

1.It’s a pretty big smoke detector.

2.It is not very sensitive.

There would have to be a LOT of smoke before the alarm would go off — the smoke would have to be thick enough to completely block out the light. It takes quite a bit of smoke to do that.

Photoelectric smoke detectors therefore use light in a different way. Inside the smoke detector there is a light and a sensor, but they are positioned at 90-degree angles to one another.

In the normal case, the light from the light source on the left shoots straight across and misses the sensor. When smoke enters the chamber, however, the smoke particles scatter the light and some amount of light hits the sensor: The sensor then sets off the horn in the smoke detector.Photoelectric detectors are better at sensing smoky fires, such as a smoldering mattress.

Ionization Detectors
Ionization smoke detectors use an ionization chamber and a source of ionizing radiation to detect smoke. Inside the ionization detector is a small amount (perhaps 1/5000th of a gram) of americium-241(CAS number is 7440-35-9), a radio active material.

This type of smoke detector is more common because it is inexpensive and better at detecting the smaller amounts of smoke produced by flaming fires.

Polyacrylamide: Just The Uses

Soil hydration has been an agricultural challenge for thousands of years. If you’ve had anything to do with irrigated agriculture in the past couple years, you’ve probably heard about Polyacrylamide(PAM). The next couple pages highlight some of the important points about this new “miracle product” for erosion control and water management.

Polyacrylamide is a polymer that is formed from units of acrylamide, a known neurotoxin. However, Polyacrylamide itself is not considered to be toxic, but is a controversial ingredient because of its potential ability to secrete Acrylamide, according to Wikipedia.

In Agriculture
To date, the primary market for this compound has been municipal wastewater treatment facilities. PAM seeks out and binds to the broken edges of clay particles, which carry a negative charge. By increasing the cohesiveness of soil particles on the soil surface of a field, PAM makes soil more resistant to the highly erosive shear forces exerted by water flowing over it. It makes the fine solids in treated water adhere to one another until they become big enough to settle out or be captured by filters to make sewage sludge, and because of this feature, its use in agriculture is growing.

The greater infiltration associated with PAM-treated furrows can boost crop yields in sloping areas such that it’s almost like giving the farmer the added yield equivalent of another irrigation during the growing season. Studies have shown that because Polyacrylamide holds the top soil in place, it also keeps phosphorus, nitrogen, pesticides, weed seeds, and microorganism out of waste water.

In Cosmetics
It is also used in cosmetics and beauty products in two different forms, either as a soft gel in its cross-linked form, which has highly water-absorbent properties, or in its straight-chain form, as a thickener and suspending agent. It has also been used recently as an active ingredient in the subdermal wrinkle filler, Aquamid.

PAM is an ingredient in a variety of cosmetic and beauty products. Small beads may also be used in skin cleansing products as an abrasive. It dries to form a thin coating on the skin, hair, or nails; in hair care products, it helps hair hold its style by inhibiting the hair’s ability to absorb moisture; in makeup, it holds together the ingredients of a compressed tablet or cake; in sunscreen products, it aids in retaining sunscreen on the skin after immersion in water. 

Light-activated Reversal of Anesthesia

In a new study, a light-sensitive moiety has been added to propofol, a commonly used anesthetic, allowing its narcotic effect to be controlled by light. The compound also offers a possible route to the treatment of certain eye diseases.

Dirk Trauner, Professor of Chemical Biology and Genetics at LMU and a member of the Excellence Cluster CIPSM, is a specialist in the art of conferring on “blind” nerve cells the ability to react to light. Working with colleagues based in Switzerland and the US, he has now developed a derivative of propofol that allows the action of the GABA receptor to be regulated by light. “By attaching a molecular switch to propofol, we have obtained a light-sensitive molecule that is a more potent anesthetic than propofol itself, in the dark,” Trauner explains.

Inhibitory neurotransmitters dampen the activity of neurons. For example, propofol, a common anesthetic, interacts with receptors on neural cell membranes that normally bind the inhibitory neurotransmitter gamma-amino butyric acid (GABA). Binding of GABA opens protein channels through which negatively charged chloride ions stream into the cell. By raising the resting electrical potential across the membrane, this makes the cell less likely to fire in response to an incoming stimulus. Propofol magnifies this effect and this functions as an anesthetic.

In this case, light serves to largely inactivate the anesthetic effect of the compound, as the researchers were able to demonstrate in experiments on tadpoles. When exposed to a low concentration of the propofol derivative, the animals were anesthetized, as expected. However, when irradiated with violet light, they promptly revived, but remained active only as long as the light was on. In the dark, they were immobilized once again. The light-dependent effect is completely reversible, as the tadpoles recovered fully upon transfer to their normal aquarium.

The new agent could be used to treat certain forms of blindness, such as retinitis pigmentosa, which leads to loss of vision owing to progressive destruction of photoreceptors. However, neurons deeper in the retina are unaffected, and are accessible to ambient light. “The inner cells also bear GABA receptors on their surfaces, and in principle they could be turned into light-responsive cells with the help of the new compound, which would allow us to bypass the defective photoreceptors,” says Trauner. He and his research group are now actively exploring this possibility. 

The Paraffin Market In China Is Dramatical On July

The paraffin market on July can be described as a dramatic change. From concentrating on insured price in northeast regions early to increased price in this week’s, and only within 10 days, the market mentality has also been greatly driven.

The price increase this time is mainly driven by three reasons:

First, the recent rally of international oil prices driven business mentality. At present paraffin(also called as Hydrocarbon oils,C12H4Cl6) price is the lowest price range in the three-year period,  profits are very substantial in the downstream products. The second half is the production season of those downstream manufacturers, a phenomenon of advancing stocking began to appear; Second, in the case of the low limit of refinery stocks, drivening by the mental of buying up not or, so providing further impetus to the enthusiasm of traders getting goods and then the market speculation factor will increase. Third, Tension refinery resources.

Domestic economic growth slowed down significantly, the domestic paraffin exports continued to decline due to the European debt crisis. On May, the export volume recorded the lowest level in nearly three years, only 24,500 tons. Overall, the shrinking demand has become an indisputable fact. Furthermore the rapid digestion of the refinery inventory is not the real improvement of demand. Though the ownstream merchants have a certain amount of inventory in the future, the situation of market adjourned flat should not be ruled out. Therefore, short-term operation should be dominated, and the long term need to cautious.

Molybdenum In Stainless & Alloy Steel

Molybdenum is an essential trace element for virtually all life forms. In industry, it ia applied in many vital fields. In human body, it functions as a cofactor for a number of enzymes that catalyze important chemical transformations in the global carbon, nitrogen, and sulfur cycles.

Description
Discovered in 1778 by Swedish Chemist Carl Wilhelm Scheele and isolated in 1781 by Peter Jacob Hjelm, molybdenum is used mainly as a component of alloyed steel. Because of its softness, color, and greasy feel, it was originally mistaken as a lead compound. A silvery white metal with an atomic number of 42, it is solid at room temperature, has an atomic mass of 95.94, and appears in the periodic table of elements under the chemical symbol of “Mo.” In fact, compared to other pure elements, it has one of the highest melting points. One most unique and therefore useful qualities is its extremely high melting point: 4753 degrees F (2623 degrees C, or 2896 K).

Uses
The most significant of the uses is as an additive in steel and iron alloys. Because of its ability to withstand extremely high temperatures, it is used in the manufacture of missiles, aircrafts, spacecrafts, rifle barrels, light bulb filaments, and furnace components. In the early 21st century, about half of all mined molybdenum was used for iron and steel alloys in construction, tools, auto parts and steam turbines.

One of the important energy-related uses of molybdenum is as a catalyst in the refining of fuel. It can be used as a chemical catalyst. Its versatile chemical structure and the ease with which it transitions between oxidation states makes it an attractive catalyst for scientists creating chemical reactions and syntheses in laboratories.

Production

The chemical can be mined directly, gleaned from ore sources such as molybdenite or molybdenum sulfide (MoS2), obtained as a by-product of copper mining, and recovered from the mineral wulfenite (PbMoO4). Molybdenum hexacarbonyl (also called molybdenum carbonyl) is the chemical compound with the formula Mo(CO)6. The United States is a significant source of Mo in the world, drawing from mines in Colorado, New Mexico, and Idaho. Other prolific producers worldwide include China, Canada, Peru, and Russia.

In Life
As an essential trace element in plants, animals and humans, the element plays an important role in the conversion of atmospheric nitrogen to ammonia. That fact makes the use in fertilizers a common occurrence. Trace amounts of dietary molybdenum is also necessary to promote growth in animals; excessive amounts however is toxic.

Diethylene glycol Maintains Vulnerable

It is reported on Monday, the London Brent futures for $ 99.77 per barrel in August, it will fall down $ 0.91.

Some experts are still concerned about the Persian Gulf situation, but the Iranian nuclear issue has been included in the international oil price factors, even if Iran selectively interrupted the tanker traffic through the Strait of Hormuz, the other countries in Persian Gulf region will avoid the Hall wood strait through the pipeline. A series of measures havn’t show apparent effect yet, while the high crude oil inventories making the closed lower yesterday, and the openning continues falling down today.

Yesterday, the diethylene glycol market of China declined, the industry was lack of confidence. However, taking the market and pull up after some profit taking, the market center of gravity down. Today the market still has no significant positive profit support, current bid should remain cautious, to the weakness of discuss disadvantaged keep steady.

Today the opening evaluate: the mainstream price of diethylene glycol in Jiangsu region   is about 6500 yuan / ton and 6450-6500 yuan / ton; the mainstream of the cans offers 6300-6400 yuan / ton in South China market; prices in North China Northeast market is about 6300-6450 yuan / ton and 7040-8040 yuan / ton.

Dabigatran Etexilate & Dabigatran

Dabigatran etexilate is a drug that acts on the body to reduce the risk of clots in the circulatory system under certain conditions. Dabigatran is a medication used to prevent dangerous blood clots in patients with atrial fibrillation. Like other drugs in its class, it makes the blood thinner and interferes with the body’s ability to produce thrombin. People should not garble the two drugs and figure out the difference between them.

Dabigatran etexilate is an enzyme inhibitor, so it blocks the action of one particular enzyme, called thrombin, on processes inside the circulatory system. In a healthy person, thrombin causes blood to clot, which is useful for open wounds and other injuries to the body that cause bleeding. In the case of people who have abnormal heartbeats, thrombin can produce dangerous clots inside the body. Dabigatran etexilate blocks thrombin from performing one step in the clotting process — turning a substance called fibrinogen into another substance called fibrin, which helps the clot to form.

Nonvalvular atrial fibrillation is a condition in which a person’s heart does not beat in a normal rhythm. Patients who have this illness are at risk of their blood clotting in the blood vessels, with these clots potentially being fatal or capable of causing strokes. To manage the risk of this happening, a doctor might prescribe dabigatran etexilate to the patient.

An anticoagulant, dabigatran prevents stroke and systemic embolism by keeping blood clots from forming. Anticoagulants interfere with the enzyme thrombin, which releases a substance that helps platelets in the blood stick together. This interference can prevent thrombin from forming, prevent it from functioning, or both.

Dabigatran is in a class of anticoagulant (”blood thinner”) medications called direct thrombin inhibitors. It works by preventing blood clots from forming in the body. Dabigatran is used to help prevent strokes or serious blood clots in people who have atrial fibrillation (a condition in which the heart beats irregularly, increasing the chance of clots forming in the body, and possibly causing strokes) without heart valve disease.

The United States Food and Drug Administration (FDA) approved dabigatran for preliminary use in 2010. It is similar to another drug currently on the market called warfarin. Both of these medications pose an equal risk of internal bleeding, which can be considered an acceptable risk if the chances of developing a life-threatening blood clot are high. There are two dosages of dabigatran that have been approved for use by the FDA. Most patients are prescribed 150 mg to take twice a day.