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February 28, 2005

The Flood 

From yesterday, I noticed my website counter going up at a almost unbelievable speed. A rapid check of my referrals, and I realized why: Tim Worstall was favourably impressed by my Recycling Myths article, and linked to it. Thanks Tim.

For a funny moment, here's a snippet of conversation between two Cockney girls I caught on the bus yesterday:

"She's in Finsbu'y Pa'k"
[..]

"Whe'e?"

"FINSBU'Y PAAK"

No wonder that Cockney is still the most difficult english dialect for me...

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February 27, 2005

Recycling Myths 2 

This is to continue the essay I began a few days ago.

In addition to the problems I presented in the first part, there is the fact that commercial plastics often contain other materials: plasticizers, fillers - which are most often pulverized minerals like calcium carbonate, but also glass powder/short fibers; even sawdust or starch. The most strange I've seen was plastic loaded with iron powder, for some special application. Then there are reinformcement materials, which can be natural, synthetic or mineral fibers. The presence of these materials must be taken into account when thinking about the recycling of plastics, and it can make things considerably more complicated.

From an economic standpoint, the recycling costs for consumer plastics are more or less equal to the production costs - this means that recycling is hardly profitable. But, often governments adopt regulations which make recycling more profitable - for example, with subsidies or tax reductions. In the extreme case, governments can make recycling mandatory.

But from an environmental standpoint, I remain rather skeptical about recycling of consumer plastics. The fact that production and recycling costs are almost equal means that the amount of energy and resources required for the two processes is similar.
In the end, the extent of separation and cleaning required depends strongly from the end-product specifications: if the end product must meet strict specifications, more in-depth selection and cleaning are required, thus consuming more energy and resources.
On the other hand, if the end product does not have to be of a high quality (for example, greenish recycled PE instead of the white virgin one), the selection and cleaning processes can be more superficial. One interesting point is that, when for example separating PVC from PET, for each kilo of pure PET we will obtain a certain amount of a mixture of say, 1:2 PVC-PET, which is good for nothing; it may be further processed to separate its components, or disposed of. It must also be noted that if undifferentiated plastics are just re-melt together, the resulting material will be ill-looking, have scarce mechanical properties, and generally be good only for very low-grade applications. (As usual, things are not so clear-cut: there are special high-shear processes of grinding that can render compatible plastics which normally are not compatible. But this is a feature that hardly counts for cheap consumer plastics).

I don't see putting the burden of differentiation on citizen's shoulders as a good solution for these problems. That differentiation cannot really be trusted because for an array of reason like lazyness, ignorance or malice is going to be less thorough than required (especially for something quite delicate like PET); at best, home differentiation can reduce the extent of differentiation that has to be done at the recycling plant (or some intermediate selection facility). Not to mention that our plastic bottle, as I wrote in the first article, is already made of two or three types of plastic. Nor I see home cleaning as a solution for the cleaning problems: again, it cannot be really trusted. In second place, that will only shift the resources and energy consumption from the plant to a number of households, but will not eliminate it (actually, for scaling reasons, I think that industrial-scale cleaning will be more efficient).

Things are quite different for engineering plastics, the likes of ABS (acrylonitrile-styrene-butadiene resins, a high performance category of polymers), polycarbonate (PC), nylon and other polyamides, hi-impact PS, polyurethanes (PU) and polyolefins; engineering plastics are used to produce the casings of electronic devices, domestic appliances, furniture, tools, parts of buildings and vehicles etc. These plastics have high mechanical (and in the case of PC also optical) properties, and are much more expensive than consumer plastics, so recycling is a considerably more interesting idea. There is another point about engineering plastics, and it's that often they can be collected in relevant quantities at one single site: car bumpers are made mainly of polyolefins, and a junkyard can easily collect hundreds of kilos of old bumpers in a month, and all this will be quality plastic, with no extraneous materials and little contaminants. Likewise, facilities for the dismantling of scrap electronic equipment already exists (electronic devices like mobile phones and computers contain small amounts of very expensive materials, and it's already a bargain to recycle those) or can be easily built. The concentration of "raw materials" means less energy spent to transport the plastic to the recycling plant, compared to the energy required for a doo-to-door recyclables collection.

To end, there are plastics that cannot be recycled, because of their chemical composition or a number of other reasons, but these plastics are mainly used in small amounts for special applications and thus they not represent a real concern.

All this discussion regards primary recycling, where old plastics are used to produce new plastics of the same kind. But there are also secondary and tertiary recycling, when old plastics are used to produce other chemicals or energy. But of those, I will eventually write in another article.

Much of the information presented here is taken from the book "Polymer Recycling: science, technology and applications", John Scheirs, Ed. Wiley 1998, Chichester; ISBN 0471970549 m.

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Even More Additions 

A blog that has to be in my list is Tim Worstall's weblog: his technical and economical knowledge, together with his scorching exposition of the absurdities in the thinking of the Left/environmentalists/Kumbaya-singers (and basically anyone else who speaks crap) make him a must read.

Another additon is Pooklekufr, one of the LGF gang. He has a nice blog; mostly socio-political commentary, but with some purely funny moments as well.

Apparently being on LGF inspired quite a few people to blog - but with all due respect, my ideal blogger is Steven DenBeste more than Charles Johnson.

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February 23, 2005

Filler: Weather & Miscellanea 

I'm too tired and busy with other things to continue the discussion of plastic recycling (or the depressive EU Constitution), so I'll fill in with some mundane stuff.

From a few days now the whole Britain is swept by northern winds bringing with them cold and snow. In London, we're having snow showers, and two nights ago about 1 cm of snow settled. That is a pathethic snowfall by any standards, but apparently it was enough to cause transportation problems in London, go figure. Anyway, more snow and temperatures barely above 0 C are forecast for tomorrow, 24 Feb.

Meanwhile, more south, the weather is no better: all of Italy is under heavy snowfall from three days, a situation that caused the temporary closure of airports and several roads and higways especially in the central regions.
In my area, the mounts south of Parma, the snowfall reached 100 cm (!) near the tops and 30 cm in the valleys. The situation will remain critical for another couple of days, and the Traffic Controllers of Bologna suggested to travel by car only in case of necessity.
In the south (Campania), the infamous highway A3 is plagued again by the snow, and also citizen protesting against the opening of a landfill site in the area. Campania had very difficult times recently with the disposal of its domestic garbage, because incinerators (and rubbish-fed power stations) and landfills have been seized and closed for a series of non-compliances with various regulations, and suspect criminal infiltrations in the management. I think that protesting against solutions to the problem is rather stupid. Especially, other regions will hardly accepts rubbish from Campania. In defense of the locals, however, it must be said that Campania had to endure for years clandestine dumping of any kind of waste, from urban to dangerous and toxic industrial waste.
One of the protestors camping nearby (or even on) the highway died last night, probably of hypothermia. I wonder if this story deserves to run for the Darwin Awards.

In other news, "Red" Ken Livingstone, the despicable Mayor of London, hardcore lefty and good friends of Islamists and jihadis (of course not great friend of Jews and Israel) is still refusing to apologize for a Jew-hating remark uttered a while ago against a Jew journalist.
Go on Red Ken, dig you grave, you've been on the political scene for far too long now.

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February 19, 2005

Recycling Myths Pt.1 

Recently, I got engaged once more in on-line discussion about recycling of post-consumer materials, particularly plastics. I'm getting tired of having to rebuke always the same fallacious arguments. So I decided to write about the problems - even myths - of polymer recycling in general. When people talk of plastics recycling, they generally refer to consumer plastics: those used for containers, packaging, bags etc. These plastics must be cheap and easy to use, and the life of disposable items is in the order of weeks - then they go in the bin. Engineering plastics are instead used for structural elements and other durable items, so in this latter case performance is (realtively) more important than price.

I thin it's advisable to begin with a brief primer on polymers in general. There are many different kind of polymers, but he most common ones for consumer products are polyethylene (PE), polypropylene (PP) - which have a very similar molecular structure, poly(ethyleneterephtalate) (PET), poly(vinylchloride) (PVC) and polystyrene (PS).
But besides the chemical class, the mechanical properties of a polymer, and hence its suitability for a certain application, are determined by the mean molecular weight. This is in turn an expression of the length of the polymer molecules (or chains): as a general rule, the longer the molecules, the better the mechanical properties. Another important factor is the shape of these molecules, because long, stick-like chains pack more tightly than irregularly shaped ones.

And here lies a big rub: polymers nowadays are produced in big plants, using processes carefully optimized (by a meticulous R&D work) to to finely control the size and shape of the polymer chains. Thus any batch of PET (for example) coming out of a production plant has constant, defined composition and properties to satisfy customer's needs at a reasonable price.

Let's now examine a common plastic bottle for soft drinks. All over the world these bottles are mainly made of PET (a few places prefer PVC or a close relative of PET, poly(butyleneterephtalate), PBT): this PET is generally clear and transparent, and from a mechanical standpoint, it must have a high tensile strength in order to withstand the pressure that can easily develop inside the bottle; a stronger plastic will also allow for thinner walls, and thus less material to be used per bottle. Another appreciated property is impermeability to carbon dioxide, so that fizzy drinks will not lose their bubbles.
Our bottle will also have a cap made of PP, and a label that can be paper attached to the bottle with a little glue, or plastic (PE, probably) tightly wrapped around it. The importance of these details will be clear later.

For now, let's suppose we have a thousand of bottles, all clear PET with no appendages to interfere, and we want to recycle them. First we have to carry them to a processing facility, and probably to do this we'll have to use a diesel-fuelled truck. A complication is that empty bottles, even if squased by hand, have a low density and thus require a large loading volume. This problem can be reduced by pressing the bottles in a tighter bale, but to do this we have to spend some energy (I worked at one of those presses, and it used a sizable electric motor, plus several liters of hydraulic oil). At the processing facility, the first thing to do is to shred the bottles in small pieces: this can be easily accomplished using dedicated shredders, but again that will cost some electricity.
Then the PET chips must be washed: our bottles did not contain just water, but probably also fizzy drinks (basically, sugar). If these contaminants are not removed from the plastic, they will cause problems afterwards. Basically, the chips are immersed in a stirred tank of water - a lot of clean water. But water alone is not very good for cleaning; there are ways around it tho: an extremely turbulent flow of water will remove basically anything from the surface of the chips, but it takes energy to create such flow. Hot water can be used, but hot water does not come out of thin air (it is true that water for the washing stage may be heated using waste heat from other sections of the recycling process, but I'm not too sure about it). Detergent and/or a little of caustic soda can be added to the water, but these chemicals must be produced in some way, and also a rinsing stage is required to remove residues of detergent/soda. Then, the effluent water from the washing stage is contaminated and probably needs to be treated before being discarded to the sewers.

After washing, our PET chips must be dried and this requires some more energy. Update 27/02: I forgot to mention, before remelting the plastic has to be pulverized, and grinders for this purpose tend to require quite a lot of electricity. The next stage of the process is re-melting, and that's where the real trouble comes.
PET for food applications must meet particular specifications regarding the release of maleodorating or toxic substances, and it must be free from impurities that can alter its colour and cause the appearance of defects in the final products. Re-melting occurs at about 280 C (prudeced by electric heating elements), a temperature that will char eventual organic impurities, causing the appearance of black specks. But that's not all: the high temperature alone is enough to cause some degradation of the plastic - rupture of the polymer chains in shorter pieces; this degradation can only get worse if water, acid or basic substances are present.
The re-melting equipment is built and run to minimize the degradation of the processed PET, and it's even possible to add small amounts of chemicals that will re-join the extremities of broken chains, but that's far from an ideal solution. After re-melting, the plastic probably has to be filtered, and pushing something so viscous through a fine filter requires a sturdy pump. Finally, our PET is extruded, the thick filaments cooled and cut into pellets using electricity-driven machines. At the end of the day, every stage of the process must be run properly, otherwise we'll obtain a product with poor specifications, which cannot be used in high-spec applications and will thus have a lower market value.
Even worse, the properties of our recycled PET may change unexpectedly, if the source material has properties different from expected - very dirty or contaminated with oily substances for example.

And this was just the almost-ideal case of clear PET, not mixed with other plastics. In practice, our bottles will always come together with some extraneous objects, and the bottles themselves have caps of a different plastic, that must be eliminated. Leaving aside manual selection and separation, that can be 100% selective but is also very inefficient, there are machines built for the purpose which use a variety of methods to identify the different polymers, both on whole objects and chips. The main problem with these machines is that, besides the usual energy comsumption, for each kg of impurities that are eliminated, at least another kg of good PET is lost as well. One nice idea is to use a specially designed centrifuge, where the highly turbulent flow will clean the plastic chips and separate them on the basis of density. Problem is, this machine is expensive to build and operate - but it does two steps of the process in one single operation. The biggest enemy of PET is PVC: at the melting temperature of PET, PVC will char producing black specks, and let off HCl that rapidly degrades the polyester. PVC also has density very close to that of PET, and it's thus very difficult to separate the two.

There is more to say about recycling, but this brief descritpion should be enough to demonstrate that everything is not as nice and easy as environmentalists say.
Recycling of plastics is possible, but wether it is a bargain in term of energy and resources saving, and wether it is profitable or not, still has to be determined - case by case.

Part 2 will follow soon, with more exciting stories!

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February 18, 2005

Stupid Regulations? No, Thanks. 

Last November my attention was caught by an idiotic proposal: labelling food items with a traffic-light style sign to indicate the level of risk posed to health.

Well, now it looks like this regulation is going down the drain:
Health chiefs are on the brink of abandoning a flagship food labelling scheme amid massive opposition from the industry.
Food and drinks firms have warned they will not co-operate with proposals for "traffic light" signs on products.

Ministers hoped the coloured symbols would help consumers choose healthier meals. But food giants insist the scheme is "unscientific" and have launched a huge lobbying offensive to derail the plan. Officials-admit they are now considering-"other options" for labelling. The traffic light scheme is outlined in the Government's White Paper on public health. The idea was that products high in salt, fat or sugar would carry a red warning symbol, while healthier options would carry green or amber signs.[...]

The industry is optimistic that the plan will be abandoned. Snacma director general Steve Chandler said: "Traffic light labelling is not something the industry will sign up to. The idea that you can distil all the nutritional benefits into a single indicator is fundamentally flawed. Even the people who helped come up with this are having second thoughts."

If the scheme is dropped, plans to crack down on TV advertising of junk food to children could also be in jeopardy. The Government had hoped to base new restrictions on the "nutrient profiling" system which could form the basis for traffic light labels. Ministers are waiting for advice from the Food Standards Agency.
Good, I say: better late than never for getting rid of some governmental nannies.

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February 17, 2005

Rude Linguistics 

I continue to get referrals from search engines of people searching for things like "fuck off italian version". I don't think they want to insult this blog, so I suppose they want to learn Italian swear words.

Well, in the optic of giving to my readers the service they request, I'll provide a quick guide to Italian swearing.

Fuck Off and variants are equivalent to Vaffanculo (the last u is pronounced as "oo") - this word is a bit hard to pronounce for English people. It has no literal meaning; sometimes is also used as interjection or expletive. Variations are 'fanculo, 'affanculo, va'nculo and others. Vaffanculo is the very Italian expression, but also fottiti has a rather widespread use.

Shit --> Merda

Fucking is equivalent to Fottuto/a, but other expressions with the same meaning are di merda, del cazzo.

Son of a Bitch is expressed with Figlio di Puttana, but while especially Americans use it quite frequently, Italians most of the times mean it, when thay say it.

Bastard --> Bastardo (That's easy)

Motherfucker and variants have no exact equivalent in Italian. The gravity or rudeness of the insult is increased by adding adjectives or prefixes: stra-fottuto, brutto figlio di puttana.

Stronzo/a literally means Turd, Piece of shit, but it's also used to indicate mean, dishonest, cheating persons. Stronzate/a means Bullshit, as Cazzate/a does. Fare una Cazzata/Stronzata is used as Fuck Up/ Screw Up.

Bitch/Slut/Whore --> Troia(Stronza)/Puttana/Maiala (Italian words ending with -a are most often feminine)

Cazzo is probably the most frequent swear word used in Italian. Its literal meaning is Cock, Dick, but it has a wide variety of uses: as Fucking or Fuck, to make a sentence more rude: Che Cazzo fai? instead of the normal Cosa fai? (What the fuck are you doing?/What are you doing?); Non capisci un Cazzo (You're dumb as fucking plank); Non ho visto un Cazzo (I did not see a fuck) etc. It is also used as interjection (that is pretty rude) or expletive.

Fucking Hell and derivatives --> Porca Troia/Puttana/Maiala. If you want to add empasis, just make a chain: Porca puttana troia lurida (Dirty) fottuta.

Ok, this is just a brief and disorganized glimpse into the swearing richness of Italian language, but I think it's enough to satisfy certain curiosities. More, eventually, will come.

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More Additions 

Doanld Sensing's One Hand Clapping: a dog of war who definitely prefers peace.

Armor Geddon: the war, in the words of who fights it with the US Army.

Marlowe's Shade: a nice commentary blog - so nice to add The Italian Version to their blogroll.

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February 16, 2005

Distribuire le Colpe? 

Ogni volta che c'é un incidente od un mancato incidente aereo, i giornali sono ossessionati dall'idea di dare la colpa a qualcuno, di trovare un capro espiatorio si direbbe. L'utlimo caso di incursione in pista accaduto a Malpensa il 14 Febbraio non sfugge aquesta regola: ecco cosa dice Repubblica.

MILANO - Aeroporto di Malpensa, il giorno di San Valentino. Sono le 12.15. Per alcuni secondi due aerei carichi di passeggeri si trovano in rotta di collisione: secondo una prima ricostruzione, uno stava atterrando a 240 chilometri orari, l'altro (un Md82 dell'Alitalia) avrebbe attraversato la pista senza autorizzazione a 20 chilometri orari. Per fortuna, grazie alle ottime condizioni di visibilità, non succede nulla: l'Md 82 sgombera la pista in tempo, l'altro aereo riesce ad atterrare. Ma l'Agenzia nazionale per la sicurezza del volo (Ansv) non sottovaluta il fatto, vuole capire il grado di rischio che si è corso e distribuire le colpe. Ieri ha aperto un'inchiesta.
Ma é davvero questo il ruolo di tale Agenzia? Per chiarire basta visitare il sito dell'ANSV e leggere una qualunque Relazione d'Inchiesta - ad esempio, quella sull'incidente di Linate, 8 Ottobre 2001 (PDF). A pagina 9 del documento si legge testualmente:

L'Agenzia nazionale per la sicurezza del volo (ANSV) conduce le inchieste tecniche di sua competenza con "il solo obiettivo di prevenire incidenti ed inconvenienti, escludendo ogni valutazione di colpa e responsabilitá" (art. 3, Comma 1, decreto legislativo 25 febbraio 1999, n. 66)
Ed una simile dichiarazione viene ripetuta poche righe piú sotto.

Capito, alla Repubblica e non solo? Le inchieste dell'ANSV non hanno lo scopo di distribuire le colpe, ma quello di stabilire le cause di incidenti ed incovenienti. Eventualmente, ci penserá la magistratura a stabilire le colpe. E' tanto difficile da comprendere?

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Time for Updates 

Recent events modified slightly the context of my two last posts, so I reckon it's better to post updates.

First, clarifications are to be made regarding the story about the Islamic blessing in Religion Education papers. David Holford writes that OCR replied to his e-mail saying that it's their policy to add the blessing (Peace Be Upon Him) as the proper Arabic graph each time a document mentions Mohammed "as a mark of respect", but the exam candidates are not expected to do so.

Still stupid political correctness and wasted respect in my opinion, but less serious than it appeared initially. Or so I hope.


The second update regards the Eason Jordan story: Charles Johnson rounds up a few more links to demonstrate that this guy was also cozy with Saddam Hussein (CNN kept eyes closed & mouth shut on Hussein's crimes to maintain access to Iraq) and the North Korean regime. A really enviable curriculum, ain't it?

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February 14, 2005

They Are Among Us 

Again via LGF, another story, but considerably grimmer than the previous one. This comes from David, a British blogger who is also a teacher. What he has to say is not pleasant:

[...]The potential problem has arisen in teaching about Muhammad. The exam board requires that every time Muhammad is written, the letters "pbuh" in parentheses be placed after it. This is shorthand for "peace be upon him". The writer therefore prays a blessing upon him everytime his name is written, as is the custom of Muslims. So I have to tell my students (over and over if there is any hope of them remembering) that they must bless Muhammad every time they mention his name.

For most, if not all, of my students, this will be no problem. Few, if any, have any religious convictions whatsoever. It's not so bad that I have to tell them to do something that I would find reprehensible. However, I am expected to model what they should do to reinforce their learning. I will never pray a blessing upon Muhammad. To do so would be to repudiate my faith. It would imply I believe the Shahada (the Muslim declaration of faith) even if those hearing or reading it were unable to infer this.[...]
So, apparently this Exam Board, the OCR, is requiring kids, many of them absolutely unsuspecting, to adopt what is effectively a religious, ritual practice. I think this is inadmissible, not only for kids of different religious persuasion but also for agnostics/atheists/generic non-believers.

It is also a sign of Islam, creeping scarcely noticed and tolerated for a distorted form of tolerance, into our Western society. This is not happening accidentally or because many westerners are embracing Islam; no, it's the result of astute and deliberate plans of cultural colonization devised by the Islamists themselves*. And a result of the spineless bureocratic and political classes, blinded by political correctness and thus willing to sacrifice freedom, our best and distinctive value, on the altar of multi-culturalism.

* Not all Muslims are part of these cabals, but many are - even unknowingly.

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Born Biased 

From LGF, we have this nice story about CNN International, a lecture by Eason Jordan (ex CNN News Executive) himself:

Thank you very much for being here tonight. Let me also thank Fidel Castro. In the earliest days of CNN, when CNN was meant to be seen only in the United States, the enterprising Fidel Castro was pirating and watching CNN in Cuba. Fidel was intrigued by CNN. He wanted to meet the person responsible. So Ted Turner, who at that point had never traveled to a Communist country or knowingly met a Communist, [went to Havana]. It was big deal for Ted and during the discussions Castro suggested that CNN be made available to the entire world. In fact it was that seed, that idea that grew into CNN International, which is now seen in every country and territory on the planet.

[..] He feels so strongly about there being just one world and one race he has banned one word at CNN -- the F word: foreign. While Ted Turner and CNN recognize nations, Ted's view is the only true foreigners are people from other planets, at least until Ted Turner meets those people. So Ted Turner does not want the word "foreign" mentioned on CNN and has called on me to enforce a ban by fining guilty CNN staffers $100 per violation.

So, here we have, black on white from the mouth of the horse, the candid statement that CNN International is owned by a tranzist and inspired by one of the few last living communist dictators. Should we still suppose that CNN International is non-biased?
It would take a considerable effort in denying the evidence.

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February 13, 2005

Scaling Problems 1 

Scaling is the whole process of making something bigger (scaling up) or smaller (scaling down). I know quite well this process regarding chemical plants and similar systems, but similar considerations can be applied to almost any system.
The main difference is that chemical plants usually need to be scaled up, from a laboratory reactor used for R&D and associated devices to a full-scale industrial plant. A lab reactor will produce just a few grams per day of products (up to say 100 g, but as usual there's a lot of variability), while an industrial plant can go up to 1000 t per day (if I remember correctly, the biggest sulphuric acid plant produces something like 2000 t/day): this obviously means that much more reagents and products (and heating and cooling fluids etc) must be processed in the same time.

So why it's scaling up so problematic? There are several factors involved, but let's start with the inescapable ones: geometry and physics.
Scaling up a system almost invariably requires to increase the size and thus volume of its parts, simply because bigger volumes are needed to contain and process greater amounts of matter. What happens when solids increase in volume? Let's consider three simple solids: a cube of side l, a sphere of radius r and cylinder of radius R and heigth h, and calculate their surface area-to-volume ratios (A/V) - why this particular ratio is useful, will be clear later.

Cube: A/V = 6/l
Sphere: A/V = 3/r
Cylinder: A/V = 2*(1/R + 1/h)

This ratio is very simple for sphere and cube, and just a bit more complex for the cylinder. However, in all three cases it's evident that the A/V ratio is inversely proportional to the dimensions of the solid. In other words, bigger solids have less surface area per unit of volume. This is a natural property of objects, and cannot be ignored.

Another issue to take into consideration for industrial/chemical plants is heat transfer. Heat transfer is the process of heat passing from a hot body (or fluid) to a colder one, like hot combustion gases ceding ceding heat to water that vaporizes in the process. But especially in chemical reactors, heat must be carried away to avoid overheating; the worst case is an uncontrolled accumulation of heat, that will cause a rapid temperature increase with damage to the system and possibly an explosion. It is thus obvious that accumulation of heat must be avoided.
Heat transfer is a superficial process - that is, the flow of heat (kJ/s) is proportional to the area of the surface through which the transfer occurs (it is also proprtional to the temperature drop and the nature of materials involved). But we have just estabilished that bigger solids have less surface area per volume unit, so one might expect that heat transfer will be more problematic for bigger components.

A nd in fact it is: R&D usually starts with small tubular reactors, of 5-15 mm of external diameter: their A/V ratio is high and, and consequently heat transfer processes usually do not represent a concern and these reactors work happily without any internal cooling systems (it would also be a hell of a job to put any kind of cooling tubes inside a tube of 5 mm internal diameter...); eventually the effluents are cooled in a simple water heat exchanger (two concentrical tubes) downstream the reactor.

But industrial reactors are big cylinders of many cubic meters volume: their surface area is small compared to their volume, and an external cooling system (like a water jacket) often is not enough to avoid local overeheating and internal cooling coils or other devices become necessary. The technology to design and build those is well known, but nevertheless they may alter the flow inside the reacor, and surely add weight, complexity and cost to the plant.

One or more following posts will deal with other cases of scaling problems.

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Service Announcement 

I decided to have new comments posted through a pop-up window, so my readers using browsers with pop-up blocking features should take the appropriate measures to allow the comment window open (in the remote case they want to post a comment here).

The comments experiment is working even too fine: up to now, only someguy from Mistery Achievement posted here, and his contributions are always friendly.

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Roast Crispy Pork 

Crispy pork is one of my favourite Chinese dishes, and I just tried to cook it at home: it was very good for the first attempt, and now I am so proud of my culinary accomplishment that I want to share it with my readers.


Ingredients:

1 piece of pork belly (about 1 kg, with uncut skin)
Chinese Five Spices
Pepper
Salt

First of all, place the belly, skin side up, on a chopboard and pierce a number of holes in the skin using a sharp and pointed knife. It's not so dull as it may seem; just think of the knife game scene in Aliens... or imagine that you are poking holes in your worst enemy, not an innocent piece of meat. Then mix 1 tablespoon of fine sea salt, 1 tbsp of freshly ground black pepper and 1 tbsp of Five Spices in a cup (you can use also mixed peppercorns, or rock salt... you get the idea); turn the belly meat side up, spread the seasoning evenly on the meat and massage it, pushing the seasoning into all the eventual cuts and cavities. Possibly, treat also the sides of the piece in the same fashion. Finally, place the seasoned belly in a plate, again skin side up, and massage the skin with a little salt. Put the whole thing covered in the fridge and leave there overnight so that the flavours of the spices will infuse into the meat.

To roast, preheat the oven to 220 C, then place a roasting stand in an oven pan and add water up to 1 - 2 cm below the stand level: during the cooking, this water will let off steam keeping the meat soft and juicy, and it will prevent the dripping juices from charring and sticking to the pan. Put the belly piece on the stand, meat side down, place in the oven and roast it without turning. I cooked mine for 35 min, but it was still rare in places. So allow 45 min to have it well-done throughout. At the end of this time, check the skin: if it's golden and sort of bubbly and crispy, it's done. But probably you will have to turn on the grill to full power and grill the piece for a short time - keep the situation under watch, because at this stage it's easy to char the skin.
When the meat is done, take it out of the oven, let it stand for a few minutes and then place on a chopboard and carve as you like - thin slices or more substantial chunks.

In the true Chinese style, crispy pork is served with plain rice and eventually stir-fried vegetables: enjoy!

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February 11, 2005

HTR Ready to Go 

A few weeks ago I wrote about the novel nuclear reactor being developed in China. Now it seems that the first full-scale plant of this kind will be built within five years in Weihai, as Channel NewsAsia reports. I really hope that this plant will work fine and open a new era in the civil use of nuclear power.

Update 19/02/05: The invaluable Tech Central Station features an article by Jeremy L. Shane exploring the market, political and strategical implications of the Chinese pebble-bed reactor program in the context of West-China relationships. And those are not small things.

Update #2, 20/02: Also Kevin Connors links to the TCS article, expressing the hope that PBR technology will mean a new era of cheap, flexible and adaptable nuclear power. Possibly, hopefully I say.

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February 09, 2005

Who First? 

You probably heard that just yesterday Palestine* leader Mahmoud and Israel's Prime Minister Ariel Sharon declared a truce after years of bloody conflict. Both sides promised to abstain from the use of force, and Israel agreed to some other conditions:

"To our Palestinian neighbours, I would like to promise that we have a genuine intention for you to live in independence. We do not want to control your lives," he said.

Mr Sharon also said the two sides had agreed on transferring "certain Palestinian areas" from Israeli to Palestinian control.

Under the arrangement, Israel will withdraw its troops from Jericho and four West Bank towns within three weeks, Palestinian negotiator Hassan Abu Libdeh said later.

Agreement was also reached on the release of Palestinian prisoners, officials from both sides said. A batch of 500 would be freed soon, with another 400 to follow later, they said.
This is not the first "hystorical agreement" between Israeli and Palestinians: another was signed in 1993 (the Oslo Accord) but it failed spectacularly - because in 2000 Arafat refused to accept the golden Israeli proposal of a Palestinian state on 98% of the West Bank and Gaza.

Will this time be different? I find it very hard to trust Abbas: he already cast himself as a new Arafat, and called Isreal "the Zionist Enemy". Will he have the will and the power to respect and enforce the truce - when Hamas and the Islamic Jihad declared clearly that they not are not bound by the agreement? I don't know now, and before we know people will die, sadly.

But Israel has to trust someone on the palestinian side, unless they want to resolve the issue with another large-scale war to drive the Palestinians away. But such a war would not be a very good idea, in my opinion: it can easily escalate to a regional conflict, and now the Egyptian army (just to name one) is much stronger than in 1973. In the worst case, I could imagine France opely giving military aid to the Arab side.
The Israeli leaders have to trust someone, and reach an agreement overcoming the concerns about the sincerity of their counterpart. But mistakes will be deadly.

There is another aspect of this agreement, anyway: it's born out of politics and force, after the Israelis basically won the Oslo War (a name that quite a few Israelis use instead of Second Intifada): the Palestinians did not gain one square kilomenter of territory; instead, they are in worse conditions than before, and many high-profile terrorists are dead or captured. Maybe, just maybe, Mahmoud abbas came to the pragmatic realization that his side will obtain nothing (except sorrow) from the use of violence, and it's thus time to work for a real peace process. Only time will tell, but what will be the toll?

* I know, there is not such a state as Palestine. But let's keep writing simple, OK?

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February 08, 2005

In The Wake 

The catastrophic tsunami that devastated the coasts of the Indian Ocean seems already descended below the radar of the mainstream media. Also, the UN tried to took credit for the relief effort, while in truth the biggest burden is carried by USA, Australia, Japan and Singapore - why China did not grab the occasion to extend her influence in the area, I cannot tell.

Also Italy, besides fundraising, began to send some operative personnel in Sri Lanka from 30 Dec 2004. At present, there are three teams of the Fire Department equipped with two Canadair seaplanes, inflatable boats and other SAR gear. These men set up tent camps to host the refugees (and are collaborating with the management of these camps), are helping with the airlift of supplies; are building wharfs to allow the operation of an ambulance boat donated by the Italian Government and other boats and are giving training to the local Fire Brigades and other rescue agencies.

Also the Italian Civil Protection is actively involved in the relief operations with several men: a few supervisors and coordinators, and a good number of medics and paramedics, pilots, ground airport personnel and communications technicians. The tent camps and field hospitals are under the responsibility of the Department of Civil Protection.

A team of forensic experts from Carabinieri is still in Thailand with the ungrateful task of identifying the victims of the tsunami.

All the above links are from Italian official websites - I could not locate english versions of the same.

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February 07, 2005

Three Cheers... Well, not Yet 

Today pubs and bars in England can start applying for longer licensing times under the new Licensing Act, a major shake-up in 40 years of regulations. Finally, I say, because it was quite ridiculous to have pubs closing at 23:00 in such a lively city as London - especially for me, given that in Italy there is nothing like licensing times; selling alcohol is allowed 24/7 by default.

It is also good to know that someone in the UK government really gets it:

Welcoming the new measure, Culture Secretary Tessa Jowell dismissed fears it would mean 24-hour boozing. She said: "The vast majority of people should be treated like the adults they are. It is ridiculous that the Government should deny the entire population the right to a drink after 11pm.

"We will give adults the freedom they deserve and yobs the tough treatment they deserve."
Of course the Nannies are already on the war footing, at they are loudly asking for, at least, a prohibition in "happy hours" and other promotions, if not a generalized price increase for alcoholic drinks. Boring. But it seems that once set in motion, this law will roll forward without being stopped. I think that a source of problems is that in Central London thousands of drunk people leave the pubs all together in a short time span, and that's often a spark for fights. With more time to drink, there will be no (or less) drunk crowds in front of pubs from 23:00 to 23:30; less concentration of intoxicated people and thus less chances of fights.

Sadly, new licenses will be issued only from November this year, damn...

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February 05, 2005

Idiocy, piles of 

The story of the three noth-african muslims acquitted from the charges of terrorism in Italy has not found a conclusion yet. The Minister of Interior Pisanu tried to have one of them, Mohamed Daki, expelled, but Milan's judges refused to allow the expulsion on the ground that Daki, although acquitted, still has to face the appeal trial and possibly a Supreme Court examination of the whole trial. Also they said that if expelled back to Morocco, his human rights may be infringed and eventually extradated to the United States.

Now Daki has been released on a sort of parole - he will have to notify his movements to the Police while probably living in the Reggio Emilia area. Ha also said that at the end of his ordeal he wants to apply for political refugee status in Sweden or Norway. Like Italy persecuted him...
Justice Forleo decided to acquit Daki, Bouyahia Maher, Toumi Alì Ben Sassi because she regards the attacks on Coalition forces in Iraq as "legitimate guerrilla".
Daki thanked the Italian judicial system: no shit, dude. You found first an idiotarian judge who acquitted you on shaky grounds to say the least, and then other dumb bureocrats who prefer to blindly follow the procedures rather than accomplishing results.

Two other defendants, Noureddine Drissi e Kamel Hamroui, are still in jail: Milan Justice Forleo decided that she has not the proper jurisdiction, and the trial should be held in the nearby Brescia. Justices in Brescia declared that they consider attacks on the Coalition and Iraqi forces (not to mention civilians) in Iraq as terrorism.

On a sidenote, Milan and Brescia courts are engaged in a strife from several years about the higly controversial trials involving Prime Minister Berlusconi and other high-profile politicians and personalities. Basically, Berlusconi's lawyers insisted that Milan judiciary environment was rife with prejudices against him, and his trial should have been held in Brescia.

However, this whole story highlights some basic issues.
One is the definition if terrorism: current definitions of terrorism emphasize the aspect of attacks to civilians, while the real distinctive element of terrorist doctrines is to cause reprisals and ovvereaction and then use an efficient propaganda machine to cast the enemies of the terrorists as evil, oppressive and cruel.

Another is the ill-based ides that Guerrilla is always legitimate, while terrorism is not. Instead, the most important distinction regards the objectives of the different parties, not the tactics used (although I have little simpathy for terrorist tactics). European resistance during WWII used terrorist tactics against the Nazis, and I do not think they should be condemned for it.

And to end, the main problem here is that western judiciary systems are tailored to deal with common criminals, not enemies of the State. The jihadis, bot the active combatants and the ones in the funding and logistics train, are enemies of the state, not criminals: they must be dealt with using an entirely different set of rules. Soldiers do not wait for a judicial sentence before opening fire on the enemy. No, I don't think that Daki and his homies should be shot on sight, but evidently the penal justice system is uneffective against them. War is a matter for the Executive Power, not the Judicial Power; it's an important distinction. In this light, I think the USA found a possible solution with the detention of enemy combatants in Camp X-Ray.

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February 03, 2005

Interferences 

I have some ideas for very different posts, one about Iraq (a never-ending topic) and another about scaling problems - and maybe some minor ideas. But my PhD work demands attention too, so for the moment I'll just thank David Boxenhorn for adding The Italian Version to his blogroll.

Well, I can also give a preview of the scaling problems. Often laymen ask "Why you engineers can't do that?" or "Why that thingie that works so nicely in a laboratory is still not used in the industry?". And sometimes they imply that engineers (and also scientists) are lazy and not putting enough effort in their work. Well, no. Scaling up a lab-size plant to industrial size is a scaling problem, and a rather difficult one. In my post I'll try to explain why things that work well on a small scale work less well on a large scale.

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February 02, 2005

Mal Comune... 

Leggendo le ultime notizie, ho scoperto che Italia, Francia e Germania hanno qualche problema nel mantanere il proprio rapporto deficit/PIL entro il limite del 3%.
Ma mentre per l'Italia si avanzano dei dubbi sulla possibilitá di restare entro i limiti, Francia e Germania ne sono giá fuori:

BRUXELLES - La Commissione europea è preoccupata per l'andamento dei conti pubblici di Italia, Francia e Germania. Nell'analizzare i programmi di stabilità 2004-2008 delle tre più grandi economie della zona euro, Bruxelles rileva che per l'Italia le misure di bilancio "non garantiscono un margine sufficiente contro il rischio di superare la soglia del 3% nel rapporto deficit-Pil", mentre per Francia e Germania, entrambe sotto procedura per deficit eccessivo, constata la situazione di "vulnerabilità" delle loro finanze pubbliche. I giudizi sono stati approvati oggi.

Ovvero, se ho capito bene, la situazione dell'Italia é un poco migliore rispetto agli altri paesi, quelle Francia e Germania che spesso si propongono come esempi di un modello socio-economico vincente. E sapete qual'é uno dei motivi citati dalla Commissione europea per l'eccessivo deficit? La spesa sociale...

Tra i rischi segnalati da Bruxelles vi e' la crescita che "potrebbe essere piu' bassa del previsto". Allo stesso momento la spesa sociale del governo potrebbe esser piu' elevata del previsto, proprio a causa della crescita insufficiente.
Si cominciano a vedere crepe nella struttura di pesante stato sociale messa in piedi da molti governi in Europa. Serie riforme strutturali, e globalmente una riduzione dei benefici, sono pressoché necessarie per evitare pesanti crisi future.

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