Tag Archives: sunflowers

Brewing up silver nanoparticles

The last time I featured green tea was in the context of couture in this June 8, 2012 posting,

First, a June 7, 2012 article by Jane Wakefield about fashion and technology on the BBC News website that features a designer, Suzanne Lee, who grows clothing. I’m glad to see Lee is still active (I first mentioned her work with bacteria and green tea in a July 13, 2010 posting). From Wakefield’s 2012 article,

“I had a conversation with a biologist who raised the idea of growing a garment in a laboratory,” she [Biocouture designer, Suzanne Lee] told the BBC.

In her workshop in London, she is doing just that.

Using a recipe of green tea, sugar, bacteria and yeast she is able to ‘grow’ a material which she describes as a kind of “vegetable leather”.

It turns out there are other uses for green tea, aside from its function in couture or as a beverage with health benefits, according to an Apr. 24, 2013 news item on Nanowerk (Note: A link has been removed),

Already renowned for its beneficial effects on human health, green tea could have a new role — along with other natural plant-based substances — in a healthier, more sustainable production of the most widely used family of nanoparticles, scientists say. Published in ACS [American Chemical Society] Sustainable Chemistry & Engineering, their Perspective article (“Greener Techniques for the Synthesis of Silver Nanoparticles using Plant Extracts, Enzymes, Bacteria, Biodegradable Polymers and Microwaves”) concludes that greener methods for making silver nanoparticles are becoming available.

The Apr. 24, 2013 ACS PressPak news release, which originated the news item,  offers a brief description of the researchers’ article,

The article describes how extracts from plants — such as green tea plants, sunflowers, coffee, fruit and peppers — have emerged as possible substitutes that can replace toxic substances normally used to make the nanoparticles. In addition, extracts from bacteria and fungi, as well as natural polymers, like starches, could serve as substitutes. “These newer techniques for greener AgNP synthesis using biorenewable materials appear promising as they do not have any toxic materials deployed during the production process,” the scientists say.

Here’s a link to and a citation for the paper,

Greener Techniques for the Synthesis of Silver Nanoparticles using Plant Extracts, Enzymes, Bacteria, Biodegradable Polymers and Microwaves by Deepika Hebbalalu, Jacob Lalley, Mallikarjuna N Nadagouda, and Rajender Singh Varma. ACS Sustainable Chem. Eng., Just Accepted Manuscript DOI: 10.1021/sc4000362 Publication Date (Web): March 28, 2013
Copyright © 2013 American Chemical Society

This paper is behind a paywall.

Math puzzles and sunflowers at the Manchester Science Festival

The Manchester Science Festival (UK) has organized a citizen science project in honour of the 100th anniversary of Alan Turing’s (Wikipedia essay) birth (from the essay [Note: I have removed links and bibiographic references]),

Alan Mathison Turing, OBE, FRS (… TEWR–ing; 23 June 1912 – 7 June 1954), was an English mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, providing a formalisation of the concepts of “algorithm” and “computation” with the Turing machine, which played a significant role in the creation of the modern computer. Turing is widely considered to be the father of computer science and artificial intelligence. He was stockily built, had a high-pitched voice, and was talkative, witty, and somewhat donnish. He showed many of the characteristics that are indicative of Asperger syndrome.

Here’s more about the project, thanks to the GrrlScientist April 16, 2012 posting on the Guardian Science blogs,

What do sunflowers and Alan Turing share in common? Basically, Turing noticed that the number of spirals in the seed patterns of sunflower heads often conform to a number that appears in the mathematical sequence called the Fibonacci sequence (0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89…). Other plants also show this pattern. When Turing came to the University of Manchester, he began exploring how this phenomenon might help us to understand the growth of plants, a field now known as phyllotaxis.

Tragically, Turing died before his work was complete, so the Manchester Science Festival is asking for you to help mathematicians explore Turing’s ideas about plant growth.

This video on the GrrlScientist posting (there are other related videos in the posting) by Brady Haran, the video journalist who amongst other projects films the Numberphile series, explains Turing’s interest in sunflowers and Fibonacci’s spiral,

You don’t have to be a mathematician to join in although it seems that it’s best if you’re in Manchester (the festival doesn’t specify residence there as a requirement), from the Turing’s Sunflowers webpage on the Manchester Science Festival website,

This spring, we need your green fingers! Join Manchester Science Festival and MOSI (Museum of Science & Industry) for a mass planting of sunflowers as part of an experiment to solve the mathematical riddle that Turing worked on before his death in 1954.

Brighten up Manchester and the Nation, whilst helping mathematicians to explore Turing’s theories about plant growth. We need you to sow sunflower seeds in April and May, nurture the plants throughout the summer and when the sunflowers are fully grown we’ll be counting the number of spirals in the seed patterns in the sunflower heads. Don’t worry – expertise will be on hand to help count the seeds and you’ll be able to post your ‘spiral counts’ online.

The results will be announced during the Manchester Science Festival 2012 (27 Oct – 4 Nov), alongside a host of cultural events connected to Turing’s life and legacy, at MOSI, Manchester Museum and other cultural spaces.

You can find out more about the Manchester Science Festival, which runs from Oct. 27 – Nov. 4, 2012, here.

Although they don’t identify it on the Turing’s Sunflowers webpage,I’m pretty sure this is a bronze of Turing seated on a bench. Someone has thoughtfully given him a bouquet of sunflowers,

Bronze of Alan Turing in Manchester. (downloaded from http://www.manchestersciencefestival.com/connect/getinvolved/sunflowers)

Have fun!