New crucibles (by alaric)

Just before the wedding, I got two crucibles. Proper A4 salamander crucibles, made from some refactory stuff, rather than stainless steel cups as I'd been using up to then.

However, the stainless steel cups are easy to lift - I punched holes in the sides near the top and put bolts through, so the thing could be lifted using barbeque tongs (the wire loops of the tongs slip over the bolts, securing the crucible). The salamander crucibles, being made of a clay-like stuff, cannot simply be drilled and fitted with lugs; the material wouldn't take the strain when at red heat.

So I had to make tongs. I picked up two 7mm square cross section iron rods from B&Q, a metre long each, and forged them into tongs by using the torch to take parts of them up to red heat, then banging them with a hammer on top of an old steel beer keg or bending by (heatproof gloved!) hand, until they had curved bits that cupped the bottom of the crucible, and met at the top with a hinge.

Well, getting the two bits the right shape for the crucible AND meeting up at the top was pretty tricky, and then we had trouble drilling through the things (using a high speed Dremel was a mistake that got the drill bits hot enough to destroy their hardening; had to use the Black & Decker to drill the holes slowly... although I only have a drill press for the Dremel. Luckily, the hole I'd made drestroying drill bits in the dremel acted as a started hole for the big hand drill). So the tongs are a bit... imperfect.

If I could weld, I could make proper ones or do what the other guys do, which is to make highly durable, large, stainless steel crucibles (as opposed to my little cups) out of thick-walled steel tubing. Not that I've ever found any thick-walled steel tubing lying around as they all seem to.

As it happens, it turns out I need a second person to use a hooked rod to make sure the crucible doesn't fall out of the tongs when I'm pouring... Ok, I don't want to do melts without another person in case I have an accident anyway, but it's wasteful to need two people to do the job of one.

Anyway, at least the things worked, enabling me to use my nice proper crucibles. It takes a long time to heat up the 1cm-thick walled clay crucible compared to my 2mm-thick steel cup, but once it's all glowing red hot, it sure melts stuff fast. What's more, it keeps the aluminium hot once I've lifted it from the furnace and while I'm pouring, enabling me to take it a bit easier in this delicate stage!

I’m a mad scientist (by alaric)

Watching Spiderman 2 has reawakened my long-slumbering desire to build a giant Farnsworth-Hirsch Fusor and stand in front of it cackling, with the cold blue light of fusion casting my twisted shadow into the dark be-girdered heights of my workshop.

There's not many things you can build from off-the-shelf components worth a few hundred pounds that will create a glowing sphere of fusing plasma to hang in space before your very eyes.

Except, unlike the fusion device in Spiderman 2, it has at least a glass-walled chamber to keep the air out and fusion fuels and exhausts inside, and if you stood in the room with it running without shielding, you'd be bathed in unhealthy radiation.

But for all the blatant silliness of the fusion device in the film, I was delighted by the many ways in which it did resemble a fusion device you could build from mail-order parts in a disused warehouse 🙂

CHROME and IRON data typing (by alaric)

IRON schemas and the CHROME type system are intertwined... more accurately, I'd say the latter was a superset of the former.

Let me give a few examples of my requirements for the system. Read more »

ARGON cryptography (by alaric)

I thought I'd like to discuss the design decisions behind the rather brief description of the "security levels" mentioned on the MERCURY page. Don't worry, you don't need to go and read it first - I'll duplicate everything in this post.

To summarise, my design requirement was to implement a cryptograhic architecture for both communications and storage of sensitive data, which allows for:

1. Both parties in a communication may have differing security requirements; the maximum of both need to be met
2. Security levels need to be specified in a way that is future proof; eg, DES would have been unbreakable in World War II, but nowadays it should only be considered suitable for relatively unimportant data
3. Physical communications links may have a certain element of external protection, rendering encryption an unnecessary burden; a cluster of servers locked in a highly screened server room together should be able to communicate sensitive data between each other in the clear, or with a fast lightweight encryption algorithm - after all, an assailant in the room with them could easily interfere with the machines themselves to get them to divulge their keys. However, the same information being shared across the public Internet would need heavy encryption, or be banned altogether.

4. Communications links and data storage devices might have a maximum security level of information they can be trusted to at all, no matter how heavily encrypted it is, because any crypto algorithm is potentially breakable.

   Read more »

Protocol agnostic middleware (by alaric)

It strikes me that perhaps one of the reasons that middleware hasn't taken the world by storm is that middleware tends to require some inconvenient protocol to access it.

Even the Web Services folks with SOAP and friends don't seem to have changed the world much, for all the effort of choosing a protocol that clients can be knocked up for easily from scratch in most environments.

However, in my work for Frontwire, I've ended up creating a server that does things in response to:

• Java RMI calls
• Work for it to do being directly inserted into an SQL database
• Scheduled events
• HTTP requests
• Incoming emails
• FTP uploads

What does that tell us about currently available middleware "solutions"? Read more »