Wednesday, 30 May 2012

Pictures of the Sky

NSB loves clouds and the sky, believing that that are a most beautiful, free, daily, constantly changing artwork that is ours to admire and enjoy - if only we can take the trouble to look up....

Not smoke from fires - just VERY low and menacing clouds. May 2017

Tram going towards sunset / portal to another universe. Mar 2017

Mar 2017, by No2 Son

Jul 2014

Setting sun at Trent Lock, 2016

Crane over the River Trent, Sep 2015

Sky over Derbyshire, Sep 2016

Scotland Borders, Aug 2016
Not sure if this is a good picture or a bad picture!

Clouds with a very flat base, bit like Thunderbird 2! Nottingham 2016

Early morning, November 2015, Nottinghamshire

Wow! 2015

Interesting lighting in Bobbers Mill, 2015

Textbook. Aug 2014

A rainbow over the Embankment Suspension Bridge, Aug 2014

A cloud with a scarf! Nutbrook Trail, Aug 2014

Indian Jones Sunset, Derbyshire, Aug 2014

Supermooon (+/- 1 day). Aug 2014

Beautiful, wispy clouds - Aug 2014

Looks to me like a child has coloured the sky in with a crayon! Aug 2014

Love the contrasts in colour here. Bright sun was behind me,
with dark clouds ahead of me -  Aug 2014

Evening Sky, Nottingham, Jun-Jul 2014

Dark skies, Still water and a rainbow over the Trent,
Nottingham, Jun-Jul 2014

Whispy, high altitude, ice crystal clouds.
Notttingham Mar 2014

A cloud with a hole in it!.
Notttingham Feb 2014

Misty Sunrise, Derbyshire, Dec 2013

World Class Sunset, Radford, Dec 2013 Pic 1 of 2

World Class Sunset, Radford, Dec 2013 Pic 2 of 2

Sunset sky, Riverside Retail Park, Nov 2013

Sunrise, Derbyshire, Nov13

Dawn, Derbyshire, Nov 13

All looking rather Biblical over the Memorial Gardens, Sep 2013

Something of a 1941 Battle of Britain stylee vapour trail thing
going on here at IKEA retail park, Sep 2013

A very solid looking layer of cloud coming in over Radford, Sep 2013

Beautiful clouds at sunset, Sep 2013

Super Hi-Res Double Rainbow, Sep 2013

Streetlight and tree, West Bridgeford, Sep 2013

Streetlights and Trees, West Bridgeford, Sep 2013

University of Nottinghams Trent Building against some full-on cloudage

A foggy night, winter 2012/13

Sunset, winter 2012/13

A pristine blue sky, marked only by a vapour trail
from a plane going who knows where? Winter 2012/13

Now THAT is what I call a cloud. . .

Sunday, 27 May 2012

Talk : Prof Hutchings on Inkjet Printing

A fascinating public lecture was held recently by the The University of Nottingham and the Institute of Materials. Presented by Professor Ian Hutchings from the University of Cambridge, the talk was entitled “From Gutenberg to the Digital Age: the Challenges and Opportunities of Inkjet Printing”

Professor Ian Hutchings is the GKN Professor of Manufacturing Engineering. He is also a fellow of St John's College, Chairman of St John's Innovation Centre Ltd. and Editor-in-Chief of the international journal, Wear.

Prof Hutchings kicked off by outlining the differences between “conventional” and “inkjet” printing:

Conventional Printing
Uses a durable plate
Contact process
Good for making lots of identical copies

Flexible, can make a different image every time
Non nontact process
Any liquid can be printed, in principle

The Prof then outlined the history of inkjet technology, describing the main arcs of its development from its uptake in industiral labelling processes in the 1980s; to popular use in home and office printers in the 1990s; to current developments in printing on demand.

There are basically two types of inkjet printing:

Continuous Inkjet printing - where a few nozzles continuously eject ink drops, which are steered to make the required pattern (or are steered to some kind of ink recovery reservoir if not required to hit the print surface, such as for spaces etc)

Drop on Demand Inkjet printing - where a larger number of nozzles are used and each drop is individually addressed . This is the kind of print process we see in our domestic printers.

Prof Hutchings went on to delve into the detail of how the drops of ink are formed by explaining that there were two main processes. In the “thermal” process, some of the ink in the nozzle is heated so that it boils to form a bubble - which forces the rest of the ink out of the nozzle. In contrast, the “Piezo electric” process causes the wall of the nozzle to deform and push out the ink. The graphic below illustrates how they work.

Piezo electric vs thermal inkjet technology -
seems to be a dead heat in this case

The drop does not come out as a neat sphere but as a head with a long tail, as shown in the schematic below (which is based on data and images from this Cambridge Inkjet Research Centre)

Inkjets are called Inkjets for a reason. . .

As an aside, the Prof mentioned that the first continuous inkjet printer was the Kelvin Siphon recorder, developed in 1858 to automatically record telegraph signals.
Kelvin's Siphon recorder worked well,
but it would be awhile before he could print out pictures from I Can Has Cheezburger

Continuing to look at the nitty-gritty of the technology behind inkjet printing, Prof Hutchings explained that the ink drop undergoes tremendous changes in the shear forces and acceleration during its transition from nozzle to paper, and the ink formulation has to be sufficiently robust to accommodate this, as well as being able to last for several years before use.

The talk then moved on talk about examples of industrial inkjet printing, including the XAAR1000 printhead (that has has 1000 nozzles and the ability to cover 130m2 per hr) and the Kodak Prosper 5000KL state-of-the-art digital book printing system

Incidentally, the XAAR website has links to some incredible state-of-the-art printing videos on YouTube. The ones on the Atlantic Zeiser GAMMA 70 printer , the Cretaprinter Real Printer printing onto ceramic tiles, and the Presta Label printing system particularly caught NSB's attention.

In terms of full printing machinery, the Kodak Prosper 5000KL is a digital book printing system of fearsome power, able to run at 200metres per minute whilst printing up to 600mm wide.

Thus far, the talk had stayed on relatively familiar territory by discussing only how to print inks onto paper substrates. But now Prof Hutchings took things to a different level by discussing how one could print metals, pointing out that there were a number of ways to do this, including the following :

i) Print molten metal.
ii) Print a suspension of metal particles in a liquid (e.g. water) and sinter.
iii) Print a metal containing compound and react to leave only metal.

This part of the talk is admirably covered by one of Prof Hutchings powerpoint presentations that is available online . Some of the images in the presentation are very impressive and show where the technology might be heading.

Prof Hutchings pointed out that inkjet drops were always 10microns or bigger, so whilst it was possible to make larger electronic structures such as solder dot arrays, it was unlikely that it would be possible to print down to the 10s of nm level that is typical for modern semiconductors.

However, inkjet printing was at the ideal scale for technologies such as displays and was a key enabling technology allowing the commercial manufacture of PLED technology screens.

But the possibilities of ink-jet printing do not end with metals. The 3D manufacturing / rapid prototyping revolution that is currently underway (in which physical components are made by printing them layer by layer) means that polymer parts with constantly increasing service temperature capabilities can be made. Similar advances are being made with printing of 3D tissue and vascular systems.

In both of these cases, it is the ability of inkjet printing to make a single, tailored and unique component that is key to their success. You can get an overview of what this technology can do, at least from the industrial components and prototyping viewpoint in this video

You can read more about organ printing in this presentation by Vladimir Mironov, one of the pioneers in this field (see also this New Scientist article).

Images : Animated GIF, Kelvin Syphon

Three and a quarter inch floppies

NSB was reading a nostalgia-fest of an article on Scott Hanselmans blog entitled "The Floppy Disk Means Save And 14 Other Old People Icons That Dont Make Sense Anymore" which contained some gentle banter on how many icons used cumputer desktops refer to items that todays youngster have no experience of. Such as old style microphones, or 3.5inch floppies. NSB thought this was worth investigating further, so asked teenage No1 son (who professes to be interested in computers) what a 3.5inch floppy is.. . . No1Son : It's your version of a memory stick. NSB : And what's a 5.25inch floppy No1Son: It's a bigger version NSB : Who much memory did they have No1Son : They couldn't even hold one song

Friday, 25 May 2012

Lecture : Dung Beetles and Drugs

The latest in the University of Nottingham’s most excellent sciency lectures saw Dr Helen West giving a presentation entitled 'Dung Beetles and Their Battle Against Drugs'.

Dr West is Associate Professor in Environmental Biology at the University of Nottingham’s Faculty of Science.

Dr West’s talk began by pointing out that there were some 10 million cows in the UK. Collectively, they produce 146million tons of manure per year. If it were not degraded by the environment, this would be enough to cover Cornwall ( NSB suspects the residents there would presumably have something to say about that, possibly starting with the phrase “Ooo-aarr”).


Dr West continued by explaining that, actually, a good quality cowpat can be quite an enticing environment for insects and the like as it provides nutrition, moisture and a protective environment.

Indeed, it can house a very wide range of flora and fauna, with many of the creatures feeding on each other, as can be seen in the schematic below.

Cowpats - There is a whole other world of activity within them. . .

Incidentally, when Dr West talks about a “good quality cowpat” what she means is one that is not too dry, has some fibrous content and is not a sloppy mess.

Moving on to talk about specific species, Dr West mentioned that those of the audience who partook of walks in the countryside will have seen cowpats with holes in them. These have been created by dung beetles (such as Geotrupes Stercorarius) that have burrowed in and, if one has patience, one can see them scurrying out from one hole and back into another. One way in which dung beetles break up the cowpat is to take balls of dung into underground tunnels and chambers, often as food for their young.

A British Dung Beetle (Geotrupes Stercorarius)

One of the first insects on the scene, as it were, of a fresh cow pat is the yellow dung fly. These eat the nuisance flies that annoy cows and people, so it is in a farmer’s interest to encourage these wee creatures. According to Dr West, a freshly laid cowpat can attract so many dung flies that they pretty much cover the entire surface. The flies prey on other insects and also lay their eggs on the surface of the cowpat.

A Yellow Dung Fly

Effects of Worming A large part of the talk covered the effects of drugs given to de-worm cows because a significant amount of the does passes right through the cow and is present in its cowpats, where it can significantly affect the amount and creatures present.

“avermectins” - a group which includes Ivermectin and are large molecules. These chemicals are toxic to the environment, indeed the National Trust advises against the use of these chemicals due to environmental concerns. In addition, this class of drugs cannot be used to worm cattle in coastal areas where the Chough live as this bird digs around in cowpats for insects to eat

Chemical Structure of Ivermectin

“milbemycins” - a group which includes Moxidectin and are large molecules similar to the avermectins but are much less toxic to the environmnent

Chemical structure of Moxidectin

“benzimadazoles” - a group which includes Oxfendazole and are small molecules.
Chemical structure of Oxfendazole
These drugs are administered either by injection or by pouring along the back of the animal. Dosage can vary from each animal in a herd being dosed 2-3 times a year down to just a proportion of the herd being dosed once a year. A survey by Stafford and Coles in 1998 found that 92% of farmers surveyed treated their animals more than once a year, with 43% treating their animals more than 3 times a year.

To assess the effect of worming on cowpats, Dr West and her team took cowpats that had been . . .er.. . “dumped” by cows that had (or had not) been wormed, placed them in buckets covered with flypaper and observed how many flies stuck to the paper.

“unwormed” cowpat sample : about 40 large flies

“wormed” cowpat sample : about 6 small flies

And the reduction in the number of flies and other insects in the cowpats results in a slowdown in the rate at which the cowpats are degraded, as shown in the following experiment. . .

The research team again took samples of “wormed” and “unwormed” cowpats and then buried them in sealed bags for various lengths of time. Initially, the cowpats were found to be about 80% organic matter. After a period of some 6 weeks it was found that the amount of organic matter was:

“unwormed” cowpat sample : 40% organic matter
“wormed” cowpat sample : 80% organic matter

Clearly, the “unwormed” cowpat sample was being broken down at a much faster rate than the “wormed” cowpat samples.

Current Research
The research team has been funded by the Esmee Fairbain Foundation to study around 80 farms in the midlands and aims to “evaluate the impact of treating livestock with anti-parasitic drugs on faunal diversity of lowland grasslands and to produce an accessible advice system for farmers”.

Dr West explained that the “advice system” would, ideally, be able to advise farmers on the most efficient and eco-friendly way of worming their cattle, as well as which drugs would be most appropriate for them, based on their farm type and local environment.

Why does it matter?
Rounding up the lecture, Dr West explained why she felt that it was important to maintain the biodiversity present in cowpats and other dung for reasons such as :

i) Better pasture quality due ot quick cowpat breakdown

ii) More sustainable agriculture

iii) More complete overall ecosystem

iv) We have a moral duty to maintain biodiversity

Image Sources:
Dung Beetle, Fly, Ivermectin, Oxfendazole, Moxidectin