Tag: silver

Brass Doorknobs of Public Restrooms

By Anupum Pant

I remember my grandma telling me to keep some water overnight in a copper pot, and in the morning, she used to drink it. I never understood why she did that. Backed by solid science, today I’m able to appreciate her age-old wisdom.

Today, to get rid of the problem causing bacteria, trusting brass doorknobs is better than trusting those triclosan lad anti-bacterial soaps. Yes, brass can kill bacteria very effectively.

Doorknobs are probably the most touched objects, especially the ones that are on the doors of a toilet at the mall. A doorknob probably even beats smartphones because a doorknob is accessible to anyone and everyone, whereas a smartphone is usually touched by a single individual.

Although, I’m not totally sure that a doorknob is really one of the most touched objects, one thing is for sure – Door knobs are the places where an incredible amount of sickness causing germs get collected. Thanks to the thousands of unclean hands coming straight from the toilet and touching the knob for the day.

And yet, you don’t often get sick after touching public restroom knobs. That is because doorknobs are normally made of brass. Brass and a couple of other metals have an ability to clean themselves – in a given amount of time these metals are able to sterilize themselves! This is called the Oligodynamic effect. Sounds like a cool name to remember because it’s easy to remember and nothing else would annoy your friends more than you bringing it up amidst conversations…

It has been tested and found that brass is able to sterilize itself in the span of eight hours. While some have tried to explain how it works, no one has been able to explain the effect in a satisfactory manner.

Other metals like silver, copper and copper alloys are able to kill bacteria better. Silver, purportedly is a very robust disinfectant. But, not many would be able to afford doorknobs made out of silver or pure copper. Instead, a far cheaper alloy consisting of copper and zinc (brass) is used to make bacteria zapping doorknobs.

Stainless steel and aluminium metals aren’t able to do this. Be careful when you have to twist doorknobs made of Steel or Aluminium. These are metals that could get you sick.

[Wikipedia]

A Book That Filters 4 Years of Drinkable Water

By Anupum Pant

I’ve written a lot about water in the past. No wonder drinking water is such a precious commodity. Still, not many have access to clean water. About a 7th of the whole world’s population don’t have clean water to drink. Every year about 3.4 Million people die out of water borne diseases.

A group of people who go by the name WaterisLife are putting in everything to change that. By working with a group of scientists from Carnegie Mellon and the University of Virginia, they have been able to come up with a novel idea that could change this. They call it the drinkable book. 

Drinkable book is a book full of cards that have been coated with silver nanoparticles. These cards bear the ability to filter dirty water and reduce the count of bacteria in it by about 99.9%. It can kill the bacteria that causes diseases like cholera, typhoid and E. coli., producing drinkable water that is as pure as tap water used in the US. Each page of this book can filter about 30 days of drinkable water. In fact, each page contains the instructions to filter water properly too. The whole book can provide 4 years of potable water. Definitely a boon to the developing countries.

Aluminium Used to be Costlier than Gold

By Anupum Pant

Unlike gold and silver, there is enough Aluminum in the world. It is in fact, the third most abundant element in the Earth’s crust. Also, it is about two times more abundant than Iron – an element which has a complete  branch of metallurgy revolving around it – Abundance of Aluminium is 2 times of that! Still, for the middle class of the 19th century, bricks made of Aluminium were things they could only dream to buy – Aluminium costed more than gold back then.

The same metal, Aluminium, certainly shines like silver. But our generation almost has no respect for it. Today, it is one of those blasé metals that is used to make disposable soda cans.

Back then, the US, to show off its wealth, decided to cap the Washington monument with a 3 kg pyramid of Aluminium. Later, since enterprising individuals found out a way to extract it in a very efficient manner, Aluminium became something that was not all that rare. People in the 19th century knew how precious it was. That was because, back then there was no good way to extract aluminium from its ore.

In the 19th century Napoleon III invited the King Siam to a dinner. He then gave himself Gold Cutlery, his troops Silver & the King of Siam Aluminium. This was no insult but an honour because aluminium was the most valuable metal on the planet at that time. Today, aluminium is $1,800 a ton while Gold is $50 million. – [Source]

In the mid-1800s, an Aluminum ingot would sell for about $550 per pound. Fifty years later, it costed around 25 cents for the same amount. What changed? Extraction.