Lithium

Lithium (from Greek lithos 'stone') is a chemical element with symbol Li and atomic number 3. It is a soft, silver-white metal belonging to the alkali metal group of chemical elements. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly reactive and flammable. For this reason, it is typically stored in mineral oil. When cut open, lithium exhibits a metallic lustre, but contact with moist air corrodes the surface quickly to a dull silvery grey, then black tarnish. Because of its high reactivity, lithium never occurs freely in nature, and instead, only appears in compounds, which are usually ionic.

 

Lithium is so soft it can be cut with scissors and it's so light that it floats on water. But it's also extremely reactive so it doesn't stay shiny or silvery very long. For this reason, it is never found "in the wild" in its pure elemental form (on earth). Similar to helium, lithium has many uses, not the least of which are lithium-ion batteries, soldering flux and, since it burns a brilliant scarlet colour, it provides those spectacular red colours to fireworks. Lithium's medicinal uses are among its most important attributes: it is critically important as a mood stabilizer for hundreds of thousands of people who find relief from the worst symptoms of bipolar disorder. Lithium also lessens symptoms for some migraine sufferers and for some who experience cluster headaches. How it works in the body remains elusive.

 

Trace amounts of lithium are present in all organisms. The element serves no apparent vital biological function, since animals and plants survive in good health without it. Non-vital functions have not been ruled out.

Applications

• Ceramics and glass - Lithium oxide is a widely used flux for processing silica, reducing the melting point and viscosity of the material and leading to glazes of improved physical properties
• Electrical and electronics - Commonly used in batteries
• Lubricating greases
• Metallurgy
• Pyrotechnics - Fireworks
• Medicine

For more information on Lithium visit:-
http://www.guardian.co.uk/science/punctuated-equilibrium/2011/feb/18/1
http://en.wikipedia.org/wiki/Lithium

 

What is Rust?

Rust is composed of iron oxides. In colloquial usage, the term is applied to red oxides, formed by the reaction of iron and oxygen in the presence of water or air moisture. Other forms of rust exist, like the result of reactions between iron and chloride in an environment deprived of oxygen.

Given sufficient time, oxygen, and water, any iron mass will eventually convert entirely to rust and disintegrate. Surface rust is flaky and friable, and provides no protection to the underlying iron, unlike the formation of patina on copper surfaces. Rusting is the common term for corrosion of iron and its alloys, such as steel. Many other metals undergo equivalent corrosion, but the resulting oxides are not commonly called rust.

Iron oxide, the chemical Fe₂O₃, is common because iron combines very readily with oxygen -- so readily, in fact, that pure iron is only rarely found in nature. Iron (or steel) rusting is an example of corrosion -- an electrochemical process involving an anode (a piece of metal that readily gives up electrons), an electrolyte (a liquid that helps electrons move) and a cathode (a piece of metal that readily accepts electrons). When a piece of metal corrodes, the electrolyte helps provide oxygen to the anode. As oxygen combines with the metal, electrons are liberated. When they flow through the electrolyte to the cathode, the metal of the anode disappears, swept away by the electrical flow or converted into metal cations in a form such as rust.

­For iron to become iron oxide, three things are required: iron, water and oxygen.

When a drop of water hits an iron object, two things begin to happen almost immediately. First, the water, a good electrolyte, combines with carbon dioxide in the air to form a weak carbonic acid, an even better electrolyte. As the acid is formed and the iron dissolved, some of the water will begin to break down into its component pieces -- hydrogen and oxygen. The free oxygen and dissolved iron bond into iron oxide, in the process freeing electrons. The electrons liberated from the anode portion of the iron flow to the cathode, which may be a piece of a metal less electrically reactive than iron, or another point on the piece of iron itself.

The chemical compounds found in liquids like acid rain, seawater and the salt-loaded spray from snow-bound roads make them better electrolytes than pure water, allowing their presence to speed the process of rusting on iron and other forms of corrosion on other metals.

For more information visit:-
http://en.wikipedia.org/wiki/Rust
http://science.howstuffworks.com/question4451.htm
http://en.wikipedia.org/wiki/Rustproofing

Why do Fireflies light up and how?

Fireflies or lightning bugs make light within their bodies. This process is called bioluminescence and is shared by many other organisms, mostly sea-living or marine organisms. Fireflies light up to attract a mate. To do this, the fireflies contain specialized cells in their abdomen that make light.

Light in adult beetles was originally thought to be used for similar warning purposes, but now its primary purpose is thought to be used in mate selection. Fireflies are a classic example of an organism that uses bioluminescence for sexual selection. They have a variety of ways to communicate with mates in courtships: steady glows, flashing, and the use of chemical signals unrelated to photic systems.

The cells contain a chemical called luciferin and make an enzyme called luciferase. To make light, the luciferin combines with oxygen to form an inactive molecule called oxyluciferin. The luciferase speeds up the reaction.

The wavelength of light given off is between 510 and 670 nanometers (pale yellow to reddish green colour). The cells that make the light also have uric acid crystals in them that help to reflect the light away from the abdomen. Finally, the oxygen is supplied to the cells through a tube in the abdomen called the abdominal trachea. It is not known whether the on-off switching of the light is controlled by nerve cells or the oxygen supply.

 

About 2,000 species of firefly are found in temperate and tropical environments. Many are in marshes or in wet, wooded areas where their larvae have abundant sources of food. These larvae emit light and often are called "glowworms", in particular, in Eurasia.
Bioluminescence is used by many creatures.  It is used as a lure to attract prey by several deep sea fish such as the anglerfish below. A dangling appendage that extends from the head of the fish attracts small animals to within striking distance of the fish.

For more information visit:-
https://en.wikipedia.org/wiki/Bioluminescence
http://science.howstuffworks.com/zoology/question554.htm

Sprites!

Sprites are a fleeting, ethereal and a relatively unknown aspect of lightning storms.
 
Since the 1960s, and probably before then, pilots have been seeing but seldom reporting what have become known as sprites and elves above the clouds. Sprites are electrically-charged lightning funnels which shoot up from the top of a cloud as much as 60 miles into the atmosphere. These charges are vivid red and usually occur in clusters of three or more but are only visible for nanoseconds. They are sometimes preceded by lower altitude red flashes known as elves, and can have striking blue tendrils which are easily mistaken for blue jets. While they are a similar visual phenomenon, blue jets are less powerful than the sprites and travel neither as quickly nor as far.

 

Because 'everyone knows' lightning goes to ground, pilots were naturally reluctant to report this phenomenon in case they found themselves grounded for hallucinating. As a result, serious research was delayed until the last 15 years or so.

While sprites are more common during positively-charged lightning storms, this is not due to any preference on the part of the sprite, but rather due to the greater internal energy of a positively charged storm. It was not until 1999 that the first sprites of a negatively-charged storm were recorded.

 

During a powerful storm it is possible to see red sprites, elves and blue  jets, but the exact atmospheric conditions which create such a show are uncertain.
 
As sprites are relatively new to the science world there is still a lot more to learn about them.

It is only with the advent of high speed photography that the existence of these light shows could be confirmed, and even with that they were first photographed by accident in 1989. Amazingly, there have since been more than 10,000 confirmed sightings. They are also known to create a very low-frequency thunder which was only recently captured with the use of specialist listening equipment.

 

As their energy is spread more thinly than the traditional thunderbolt due to the cone like dispersal from cloud to atmosphere, they are thought to be relatively weak. Sprites are cold plasma phenomena that lack the hot channel temperatures of tropospheric lightning, so they are more akin to fluorescent tube discharges than to lightning discharges.

The effects of sprites are currently being investigated by various agencies including NASA who seriously addressed them as a possible cause for the tragic loss of the space shuttle Columbia, which was, incidentally, on a mission to record data about the very same sprite phenomenon.
 
The link below shows footage from the ISS and shows a red sprite over East Asia at around 0:06.
http://upload.wikimedia.org/wikipedia/commons/f/f8/Red_Sprite.ogv

Sprite Halos
Sprites are sometimes preceded, by about 1 millisecond, by a sprite halo, a pancake-shaped region of weak, transient optical emissions approximately 50 kilometres (31 mi) across and 10 kilometres (6.2 mi) thick. The halo is centred at about 70 kilometres (43 mi) altitude above the initiating lightning strike. These halos are thought to be produced by the same physical process that produces sprites, but for which the ionization is too weak to cross the threshold required for streamer formation.

Recent research carried out at the University of Houston in 2002 indicates that some normal (negative) lightning discharges produce a sprite halo, and that every lightning bolt between cloud and ground attempts to produce a sprite or a sprite halo.

For more information visit:-
http://en.wikipedia.org/wiki/Sprite_(lightning)
http://h2g2.com/approved_entry/A13492398
http://apod.nasa.gov/apod/ap990616.html

The humble Dandelion. What is it good for?

The Dandelion is known by it's latin name of Taraxacum officinale.  There are a number of similar plants labelled false dandelions but we'll look at the one we all know.

They are native to Eurasia and North and South America, and two species, T. officinale and T. erythrospermum, are found as weeds worldwide. Both species are edible in their entirety. The common name dandelion comes from the French dent-de-lion, meaning "lion's tooth".  They have very small flowers collected together into a composite flower head. Each single flower in a head is called a floret. Many Taraxacum species produce seeds asexually by apomixis, where the seeds are produced without pollination, resulting in offspring that are genetically identical to the parent plant

Lions tooth leaves

 

Dandelions are tap rooted biennials or perennial plants.The tap root on a dandelion can reach up to a foot and a half in length.  This is why they are so hard to remove.  If some root is left behind after pulling them up they will regrow.

A Beneficial Weed
The dandelion plant can be a beneficial weed, with a wide range of uses, and is even a good companion plant for gardening. Its taproot will bring up nutrients for shallower-rooting plants, and add minerals and nitrogen to soil. It is also known to attract pollinating insects.  Taraxacum seeds are also an important food source for certain birds

As a noxious weed
The Dandelion is considered to be a nuisance in residential and recreational lawns. It is also an important weed in agriculture and causes significant economic damage because of its infestation in many crops worldwide.

However Dandelion has many medicinal uses.

Medicinal uses
Historically, dandelion was prized for a variety of medicinal properties, and it contains a wide number of pharmacologically active compounds. Dandelion is used as a herbal remedy in Europe, North America and China. It has been used in herbal medicine to treat infections, bile and liver problems, and as a diuretic.

The Dandelion is actually full of full of vitamins A, B, C, and D, as well as minerals such as iron, potassium, and zinc. Dandelion leaves are used to add flavour to salads, sandwiches, and teas. The roots are used in some coffee substitutes, and the flowers are used to make wines!

For more information visit:-
http://en.wikipedia.org/wiki/Taraxacum
http://umm.edu/health/medical/altmed/herb/dandelion

The Laboratory Coat.

A white coat or laboratory coat is a knee-length overcoat worn by professionals in the medical field or by those involved in laboratory work. The coat protects their everyday clothes and also serves as a simple uniform. The garment is made from white or light-coloured cotton,  or cotton polyester blend, allowing it to be washed at high temperature and make it easy to see if it is clean.
 
When used in the laboratory, they protect against accidental spills, e.g. acids. In this case they usually have long sleeves and are made of an absorbent material, such as cotton, so that the user can be protected from the chemical. Some lab coats have buttons at the end of the sleeves, to secure them around the wrist so that they do not hang into beakers of chemicals.
 
For added safety, a variant of the lab coat, called a "Howie" style lab coat is often adopted . It is called that after a 1978 report commissioned by the UK department of Health and Social Security to codify standard clinical laboratory practices, chaired by a JW Howie. Among the codified standards was protective clothing - the type of wrap around full-coverage lab coat which had been in use in the UK for over a hundred years was nicknamed the "Howie-Style" coat to indicate its compliance with the provisions of this report. It has the buttons on the left flank, elasticated wrists and a mandarin collar and is quite similar to a chef's uniform and designed to minimise pathogen contact with street clothes.
 

Although, most lab coats are not designed to be impermeable to hazardous substances or flameproof, they provide additional safety because they can be quickly removed to isolate harmful exposures or flames.

 

• Do wear a lab coat when a Personal Protective Equipment (PPE) Hazard Assessment of the laboratory determines hazards to the body are present or likely to be present. A good rule of thumb is to wear a lab coat at all times when working in a lab.
• Do wear lab coats that cover the knees and have full length sleeves.
• Do keep lab coats completely buttoned up. Snap closures are preferred over buttons or zippers to keep the body covered and allow quick removal in an emergency
• Do immediately remove a lab coat if on fire or if there is obvious hazardous contamination
• Do consider the addition of a rubber apron when there is a significant chance of exposure to corrosive materials
• Do keep lab coats clean.  If they become contaminated they should be decontaminated or cleaned on site, sent away for cleaning by professionals who have been informed of the hazards or disposed of as a hazardous material.
• Don't wear lab coats unbuttoned as that can compromise a wearers safety

 

If you know or suspect that your laboratory coat has become contaminated with hazardous chemicals follow these rules:

• If the chemical is safe to dispose to drains (e.g. most Acids and Alkalis), rinse it clean in water before sending it to be laundered.
• If the spill was a solvent it must have completely evaporated off before it is cleaned.
• Toxic chemicals spilt on a lab coat will require that it be disposed of via chemical waste.



Lab Coats

P&R Labpak Limited offer a range of laboratory coats and currently have some on special offer.  Terms and conditions apply.

Please visit http://www.prlabs.co.uk/news/article.php?Id=195 for details.
http://www.prlabs.co.uk/news/article.php?Id=294

 

 

 

 

Sustainability!!

Everyone wants to be greener and help the environment but it's not always easy.  There is a trend to buy more economical products for the laboratory.  We use less energy overall remembering to turn lights and equipment off.  But what else can we do?

Now you can help just by buying VWR Collection products that you may well buy anyway!  And if you don't why not give them a try?

If you buy £1000 of VWR Collection products then VWR will have 10 trees planted in your name and match that donation.  You'll also get a certificate of your contribution to global reforestation!

Read the flyer on our webpage for more information on what to do.  Visit http://www.prlabs.co.uk/news/article.php?Id=194

Let's see how many trees we can plant!

Terms and geographical limitations apply to this particular offer.