Life of a university student

Where have I left off

2007-11-23T23:47:00.001+08:00

So I am finally a university student.

University stresses me off right now. Stacks of work. Canteen food is crap - not as good as home food anyways.

This post will be about food I prepared for lunch and dinner today.

LUNCH -

DINNER -

By the way, I am so pissed off on my neighbour who spilled all my blueberries on the floor...

Pistol shrimp - woah...

2007-05-30T16:36:00.000+08:00

Heroes SEASON FINALE soon!!

2007-05-17T13:24:00.000+08:00

OMG so excited. So many questions unanswered!

This is hard! solution

2007-05-16T11:21:00.000+08:00

Solution kindly provided by datr. Elaborated a bit by moi.

First let u = 1 - 3x - 2x^2.

Then du/dx = -3 - 4x

So, force the numerator into -3 - 4x, like so:

1 + 2x = -1/2(-2 - 4x) = -1/2(-3 - 4x + 1) = - 1/2(-3 - 4x) - 1/2

Hence, the integral must be split into two integrals, one relatively easy to solve by chain rule since numerator is derivative of the denominator.

First one easily solved using chain rule (or by inspection), and the second one needs a bit more working. Can change the second integral to a standard form if you complete the square and take the factor of 1/sqrt2 out.

Then just use arcsine to finish it off!

This is hard!

2007-05-14T14:15:00.000+08:00

Really! This will hopefully be the hardest integration problem I will ever encounter for school!

I won't even bother solving it here using this stupid keyboard, but a tip: hyperbolics. And if you actually bother solving this - then how about writing the working and solution in LaTeX, and I could copy and paste it here so that everyone could enjoy the maths! :)

Last year

2007-04-28T12:11:00.001+08:00

Monday and Tuesday

Wednesday to Saturday

Sunday

Book recommedation

2007-04-23T14:18:00.000+08:00

I recommend "Physics for Future Presidents" by Richard A. Muller to those who want to know what physics is really about, but want to avoid the mathematics behind it.

It talks about very interesting topics such as how chocoloate chip cookies contain more chemical energy per gram than TNT and yet it is not used as a weapon, or how the "flying disks" in the Roswell incident are just microphones to detect noise from nuclear bombs.

So, learn more physics without losing interest in it!

Buy from Amazon.com: http://www.amazon.com/Physics-Future-Presidents-Richard-Muller/dp/142662459X

Alternatively, you could watch Richard's lectures FOR FREE: http://webcast.berkeley.edu/course_details.php?seriesid=1906978373

You could thank me later. Back to more boring A-level physics revision.

Shock, horror, and sadness

2007-04-18T22:56:00.000+08:00

By now, you should already know about the massacre in Virginia Tech University. Thirty-three people were killed, whom were either students or professors. We are unwillingly reminded that these horrific events could occur at any time, in any place...

Rat monkey depression

2007-04-05T21:07:00.001+08:00

I am depressed.

This is the point when you either read on or leave this website or watch the video below, then leave.

Yes, I am depressed today. Even the video above doesn't cheer me up. I won't go into the reasons behind this depression - there are just too many, and they are probably irrational anyways. When you are depressed, well, when I am depressed, I am tired, unmotivated, bored. I feel like time is slowed down - everyone's minding their own business and probably having fun, while I sulk... in my bedroom... all day. I haven't done much today - I woke up very late, took a shower, ate, sat, ate. So yeah, not a good day today.

Depression. Depressed. Logically speaking, they should be happy words. Pressed is like stressed, and depressed seems like you are relieved. But no, it's a sad sad word. Anyways, when you are depressed, you also don't know what you talking about. You have bad dreams. I've dreamt about having to do essays for homework for two nights in a row - and they are english literature ones too! How screwed up is this? I don't even take english literature anymore - and for some twisted reason they haunt me in my dreams.

Let me check the dictionary to see whether I am actually depressed:

• noun
1 severe despondency and dejection, especially when long-lasting and accompanied by physical symptoms.
2 a long and severe recession in an economy or market.
3 the action of depressing.
4 a sunken place or hollow.
5 Meteorology a cyclonic weather system.

I think I could ignore two to five. But what the hell is despondency and dejection! God damn it!

despondent
• adjective in low spirits from loss of hope or courage.

dejection
• verb sadness or low sprits.

Well, I am kind of despondent in a way - low spirits definitely, don't know if I have loss of hope/courage though. Hope for what? I have nothing to hope for! Dejection - yes.

So I am definitely depressed. And this is going to last for quite a long time. Until something drastic happens - I mean when I win a lottery ten times in a row as opposed to experiencing a car crash.

Nobody said there was going to be a good ending!

Bye!

Edit: Not so depressed anymore. :)

Magnetism: Ferro, Para, Dia

2007-03-31T22:19:00.000+08:00

FERRO | Ferromagnetism is the "normal" form of magnetism which most people are familiar with, as exhibited in horseshoe magnets and refrigerator magnets, for instance. It is responsible for most of the magnetic behavior encountered in everyday life. The attraction between a magnet and ferromagnetic material is "the quality of magnetism first apparent to the ancient world, and to us today," according to a classic text on ferromagnetism. Ferromagnetism is defined as the phenomenon by which materials, such as iron, in an external magnetic field become magnetized and remain magnetized for a period after the material is no longer in the field. All permanent magnets are either ferromagnetic or ferrimagnetic, as are the metals that are noticeably attracted to them.

No interesting video clip to show. Just find your own magnet!

PARA | Paramagnetism is a form of magnetism which occurs only in the presence of an externally applied magnetic field. Paramagnetic materials are attracted to magnetic fields, hence have a relative magnetic permeability greater than unity (or, equivalently, a positive magnetic susceptibility). However, unlike ferromagnets which are also attracted to magnetic fields, paramagnets do not retain any magnetisation in the absence of an externally applied magnetic field.

Elements/compounds could be paramagnetic if they have unpaired electrons. The following are some examples of paramagnetic elements:

Aluminium Al [13] (metal)
Barium Ba [56] (metal)
Oxygen. O [8] (non-metal)
Platinum Pt [78] (metal)
Sodium Na [11] (metal)
Strontium Sr [38] (metal)
Uranium U [92] (metal)
Technetium Tc [43] (artificial)

Compounds

Many salts of the d and f transitional metal group show paramagnetic behaviour. Examples are:

Copper sulphate
Dysprosium oxide
Ferric chloride
Ferric oxide
Holmium oxide
Manganese chloride

The below video clip shows a liquid oxygen bridge suspended by a strong u-shaped magnet. This demonstrates the fact that magnetic force > gravitational force.

DIA | "This is a live frog. An object does not need to be superconducting to levitate. Normal things, even humans, can do it as well, if placed in a strong magnetic field. Although the majority of ordinary materials, such as wood or plastic, seem to be non-magnetic, they, too, expel a very small portion (0.00001) of an applied magnetic field, i.e. exhibit very weak diamagnetism. The molecular magnetism is very weak (millions times weaker than ferromagnetism) and usually remains unnoticed in everyday life, thereby producing the wrong impression that materials around us are mainly nonmagnetic. But they are all magnetic. It is just that magnetic fields required to levitate all these "nonmagnetic" materials have to be approximately 100 times larger than for the case of, say, superconductors. This experiment was conducted at the Nijmegen High Field Magnet Laboratory."

A large black superconducting disk was cooled with liquid nitrogen. When the disk goes into the superconducting state it expels magnetic field. This is called perfect diamagnetism. If you place a magnet above the disk when it is superconducting then it will levitate. This is known as the Meissner effect.

[99% Wikipedia and YouTube.]

Chemistry degrees

2007-03-30T07:29:00.000+08:00

Emily Wilson
Bristol
Friday February 16, 2007

"It is 9am on a Monday morning and 60 or so third-year chemistry students are already in their seats, files and pencil cases at the ready. Dr Chris Russell - young and dressed in a brown-striped shirt and chinos - will be our guide to inorganic chemistry for the next 50 minutes. And he's off, chalk flying!

Russell talks about "planar ML3 and ML2 fragments", "ligands" and "non-bonding orbitals" with clarity and enthusiasm. It is all entirely familiar to me - and yet utter gobbledegook.

Russell draws pretty, floaty diagrams on the blackboard with Ls and Ms and dots. L must stand for "ligand", whatever that is. But M? There is a periodic table on a wall of the lecture hall, but there is no M on it. Then Russell mentions "transitional metal chemistry", and the truth dawns: M stands for "metal", and I am, by any measure, the dumbest person in the room.

I studied at Bristol's school of chemistry from 1988 to 1991. I chose chemistry for a bunch of non-reasons - it was like, you know, one of my A-levels, and I was like, 18, and did not have a clue what I wanted to do with my life. In the event, it proved to be the exact opposite of a doss: both difficult and staggeringly time-consuming. It was a 9-to-5 business, five days a week.

Back in my day, the course was divided into three disciplines: copying, swotting and lab survival. In lectures there was no time for comprehension: our task was to accurately copy down reams of scribbled diagrams and equations from the blackboard. If you skipped a lecture, it would take at least 50 minutes to copy someone else's notes, and then you could never be sure that they hadn't made some awful error. (I wonder now why we never used a photocopier, but then this was at a time when undergraduates had no access to computers: I saw my first one two years after leaving university.)

Then there was the swotting: revising for exams became the time when you had to make sense of your notes, and that took out months of our lives. And finally there were the labs, where we spent our afternoons - a quite literally explosive mixture of deadly chemicals, teetering glassware, open flames and blind panic. It was all deeply Victorian, and we work-shy children of the 1970s were made to feel like proper no-marks most of the time.

University science is now in real crisis - particularly the non-telegenic, non-ology bits of it such as chemistry. Since 1996, 28 universities have stopped offering chemistry degrees, according to the Royal Society of Chemistry.

The society predicts that as few as six departments (those at Oxford, Durham, Cambridge, Imperial, UCL, and Bristol) could remain open by 2014. Most recently, Exeter University closed down its chemistry department, blaming it on "market forces", and Bristol took in some of the refugees.

The closures have been blamed on a fall in student applications, but money is a factor: chemistry degrees are expensive to provide - compared with English, for example - and some scientists say that the way the government concentrates research funding on a small number of top departments, such as Bristol, exacerbates the problem. The upshot is that Britain is turning out fewer and fewer chemists - even though there are jobs for them. Against this backdrop, it seems quite important that chemistry teaching is making an attempt to pull itself into the present; that it is as engaging as it can be; that it is no longer quite the dusty experience that it was in the early 90s.

Back in lecture theatre two, Russell is talking about "delta symmetry orbitals". You can see that he cares. He is one of the most popular lecturers here, the students tell me later.

All these students, I realise, have arrived with the notes for this lecture already in their possession - printed out from a website that also provides them with sample exam questions and workshop material. Their only job here is to annotate their notes if asked to. What a brilliant leap forward. The death of the science of copying. Later, a professor tells me that the real problem now is to keep the students' attention for the full 50 minutes.

Suddenly, a word that normal people and even journalists have heard of ... "Polonium is named after Poland," says Russell. "But that's by the way," he adds. We're back to ligands.

At 10am I have a physical chemistry tutorial with three first-year students. We sit around a little table. The students seem very young, and sweet, the bloom still fresh on them. Professor Andrew Orr-Ewing is quietly spoken, calm and super-clear. We work through a set of questions that cover the "particle in a box theory" and "tunneling effects". I sit frozen with terror, in case Orr-Ewing asks me a question and it becomes clear that I have forgotten everything I learned here. When he asks the students questions, I flinch for them, but they seem to know their stuff . There is no way I would have been so sharp in my first year here - what has happened to undergraduates?

Lisette Voûte is 21 and a third year; she is doing a four-year version of the course and will emerge next year with an MSci. She is of the opinion that chemistry's rigours are an excellent foundation for life, and says, "It's a great degree to have."

She is positive about the way it is taught, and says you can now complain if lecturers are rubbish. But then Voûte went into this knowing what she would be up against, and she knows what she wants to do at the end of it: she is the exact opposite of the hopelessness that was me at 21. Maybe all those debts and top-up fees have made students more wised-up. Then I meet another student, who asks not to be named. Why did he do chemistry? He is not sure. Does he like it? No - it is "baffling", and if he'd had any idea how hard it would be, he wouldn't have done it. What will he do next? He doesn't know. This could be me, 16 years ago. "But these are meant to be the best years of your life, right?" he says.

"God no!" I say. "I was miserable at university. I made a mess of everything. My private life was a car crash. I didn't like my course. I felt totally useless. Of course I'm a million times happier now!" He looks at me - an ancient person, on the verge of Zimmer-dom - and I can see that he is not convinced.

Later, when I meet up with my former organic chemistry lecturer, Dr Lionel Hart, I ask him if students have changed since he first started teaching? "No, not at all," he says. "They're just the same."

Bristol's school of chemistry, once a monument to 60s concrete, has had a face-lift since my time here - from the outside, it looks less like a Doctor Who set than it did. There is a new reception area. And the department has just been fitted out with state-of-the-art labs - though it turns out that even the old labs are pretty fancy these days. Someone has decided that wooden benches encrusted with decades' worth of toxins are not a brilliant idea in a human-rich setting, and they have all been replaced with gleaming white counters and computers. Lab specs have changed too. Out go the NHS clear plastic ones, in come bendy ones with blue piping. The labs still stink of solvents though - which really can't be a good thing.

Meanwhile Dr Paul Wyatt, the director of undergraduate studies, has come up with a computer programme that will soon allow undergraduates to practise experiments in a virtual setting before they get into the lab. This will be another big step forward - especially as doing your experiments first on the computer will be heavily compulsory.

It will still be lab though. And it will still be really hard. On the train home, it occurs to me that perhaps the building blocks of chemistry are, necessarily, inescapably hard and dry. However many computer tricks they come up with, however shiny the labs, perhaps undergraduate chemistry is simply un-sex-uppable. There is stuff you need to learn if you are going to be a chemist, and there is a lot of it, and it is difficult. And that's the deal, even though, these days, that is not the sort of deal people relish. Perhaps only Voûte's view - that courses such as chemistry are "good" degrees to have - can save us from becoming a nation with no idea what an atom is."

Source

Just wanna have fun!

2007-03-29T21:04:00.000+08:00

Tasty (?) Conversion

2007-03-27T19:18:00.001+08:00

2000 pounds of Chinese soup = Won ton

Why base 10?

2007-03-20T13:50:00.000+08:00

Have you ever wondered why we chose base 10 for our number system? E.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 etc. and not 0, 1, 2, 10, 11, 12... (base 3).

Obviously, because we have 10 fingers. But that's kind of selfish of us - and should I also say not very mathematical. Tens do not occur often in nature anyways - it just so happens that we have 10 fingers.

Interestingly, before base 10 was universally used, base 11, 12, and 20 have been used. This is shown in our languages. E.g. eleven, twelve, as opposed to oneteen, twoteen; or vingt and quatre-vingt in french.

Base 2 is singled out as the one with the smallest possible base. Only digits 1 and 0 are used. Every other number could be represented by 1's and 0's. So that 1 + 1 = 10 and 1 * 1 = 1. The obvious disadvantage of this binary system is that long expressions are needed to represent even small numbers. E.g. 79 is expressed as 1001111, which is really 7*10^1 + 9*10^0 = 1*2^6 + 0*2^5 + 0*2^4 + 1*2^3 + 1*2^2 + 1*2^1 + 1*2^0. But multiplication is very easy. And other possible problems may also be easily solved with binary. Is this what God uses?

American view?

2007-03-04T13:05:00.001+08:00

Is this how americans view the world?

I don't mind, I don't know much of the world myself. But spell the elements of the periodic table right!

Stop Global Warming Now

2007-02-27T19:41:00.000+08:00

By doing things on this list, and sharing this list:

http://globalwarming-facts.info/50-tips.html

A wins M any day

2007-02-26T20:08:00.000+08:00

What if...

2007-02-23T20:11:00.000+08:00

An asteroid crashes Earth. It is possible. Should we be worrying? Should we be preparing? When I say 'we', I mean the entirety of the human race.

Everything we've done would be wasted.

A collection of science jokes: Part 1

2007-02-21T23:30:00.000+08:00

There was once 3 scientists on the beach: a biologist, a chemist, and a physicist.

The biologist said: "I want to study the coral structure of the sea". So he went into the sea never to be seen again.
The physicist said: "i want to study the physics of the sea wave".' So he went into the sea and was carried away by the current never to be seen again
The chemist took out a pen and paper and wrote down: "Both biologist and physicist are soluble in water."

-

An pair of atoms are walking down a street. One says to the other "I think I've lost an electron!" "Are you sure?" said the other. "Im positive!"
Another atom finds the electron and says "I'll keep an Ion it for you"

-

An atom says to a shopkeeper, "How much are these neutrons?" He replies "Oh them, they're free of charge"

-

My names Bond. Ionic Bond. Taken, not shared.

-

There is this farmer who is having problems with his chickens. All of the sudden, they are all getting very sick and he doesn't know what is wrong with them. After trying all conventional means, he calls a biologist, a chemist, and a physicist to see if they can figure out what is wrong. So the biologist looks at the chickens, examines them a bit, and says he has no clue what could be wrong with them. Then the chemist takes some tests and makes some measurements, but he can't come to any conclusions either. So the physicist tries. He stands there and looks at the chickens for a long time without touching them or anything. Then all of the sudden he starts scribbling away in a notebook. Finally, after several gruesome calculations, he exclaims, "I've got it! But it only works for spherical chickens in a vacuum."

-

Q: What is the name of the molecule CH2O?
A: Seawater

-

To end with a historical note:

In the 1980's, in an effort to increase public awareness about the importance of chemistry, the American Chemical Society posted billboards with a picture of C6H10 and the title, "It takes alkynes to make a world."

Happy CNY!

2007-02-17T14:09:00.000+08:00

Happy Chinese New Year!

Wish you all a safe and healthy year!

Derivation of the most beautiful identity

2007-02-16T11:17:00.000+08:00

I want to share this with you. The derivation of one of my favourite identites in mathematics so far:

Let f(x) = cos x = a + bx + cx^2 + dx^3 + ex^4 + fx^5 + ...

(don't mix up e in ex^4 with e = 2.7182821828...; in this case e is just any constant)

so

f(0) = cos 0 = 1 = a, thus a = 1

f'(x) = -sinx = b + 2cx + 3dx^2 + 4ex^3 + 5fx^4 + ...
f'(0) = -sin0 = 0 = b; thus b = 0

f''(x) = -cosx = (2*1)c + (3*2)d + (4*3)ex^2 + (5*4)fx^3 + ...
f''(0) = -cos0 = -1 = (2*1)c; thus c = -1/(2*1) = -1/2!

f'''(x) = sinx = (3*2*1)d + (4*3*2)ex + (5*4*3)fx^2 + ...
f'''(0) = sin0 = 0 = (3*2*1)d; thus d = 0

f''''(x) = cosx = (4*3*2*1)e + (5*4*3*2)fx + ...
f''''(0) = cos0 = 1 = (4*3*2*1)e; thus e = 1/4!

...

and so on.

Therefore substuting the constants into the original polynomial equation,

(i) cos x = 1 - x^2/2! + x^4/4! - x^6/6! + x^8/8! + ...

You can check this by substitution a value in x, such as 1 (radians).

Similarly, you can work out an expansion for

(ii) sin x = x - x^3/3! + x^5/5! - x^7/7! + x^9/9! + ...

(iii) e^x = 1 + x + x^2/2! + x^3/3! + x^4/4! + x^5/5! + ...

Now using expansion (iii), you can expand e^(ix), where i = √(-1)

(iv) e^(ix) = 1 + ix + (ix)^2/2! + (ix)^3/3! + (ix)^4/4! + (ix)^5/5! + ...

= 1 + ix - x^2/2! - i(x)^3/3! + x^4/4! + i(x)^5/5! + ...

Separating the imaginary parts and real parts,

e^(ix) = (1 - x^2/2! + x^4/4! - x^6/6! + ...) + i(x - x^3/3! + x^5/5! - x^7/7! + ...)

= cos x + isin x

Wow!

so you get Euler's identity

e^(ix) = cos x + isin x

And a special case of it, is when x = π

e(iπ) = cosπ + isinπ = -1 + i(0) = -1

Rearrange, then you get

e^(iπ) + 1 = 0

an equation connecting the fundamental numbers i, π, e, 1, and 0 (zero), the fundamental operations +, ×, and exponentiation, the most important relation =, and nothing else.

Wow! Wow! Aren't you excited? (Nerd... if you actually read through all of the above and understood it.)

Gauss is reported to have commented that if this formula was not immediately obvious, the reader would never be a first-class mathematician.

It doesn't stop here though.

This opens a lot of branches in mathematics. One example is the hyperbolic function, which links circular and exponential functions - something you usually think as very separate branches of mathematics.

Fried rice kung fu!

2007-02-09T18:28:00.000+08:00

Yum...

If only I could produce that fried rice everyday, I could save money at university (+ avoid eating crappy food). I could also sell my fried rice. I could take over the university canteen. Hahaha

I better start cooking now! Hai ya! Hai ya! Hai ya!

Video from averagebetty.

Get the fried rice recipe from the fried rice demon.

Series

2007-02-08T16:16:00.000+08:00

Can you see that 1^3 + 2^3 + 3^3 + .... + n^3 = (1 + 2 + 3 + ... + n)^2?

Tutoring - Day #1 and #2

2007-02-06T21:38:00.000+08:00

Well it was (Feb 6, 2007) officially my first day of tutoring, i.e. I get paid for it. My tutoree/student is my neighbour, and it is going to be on a daily-one hour basis.

And, well so far it was crap. Better than expected. Actually you know what - maybe for a nine year old, it's quite good. He's polite but extremely hyperactive - so it seems that more than half of what I say to him goes out the other ear. What I mean by hyperactive: throwing basketballs, blowing air with his basketball pump, playing with his sportsband - you love basketball - I get it!

Right now, I am teaching him English, Maths and General studies. Wow! I must say kids these days learn a lot of things! Too much too soon, in fact. For example, in general studies, he already learns about annular solar eclipses and refraction of light! And in maths - manipulation (addition/multiplication all of that) of decimals and fractions? That's what we did in secondary school - not in primary?!

My rule of thumb: Less is MORE.

So yeah, he's not doing very well - and I can understand why. Duh? How can he absorb all that information. There must be something wrong with the syllabus. And the teaching at school too. He says (let's call him David from now on) that he must follow exactly what the textbook (word for word) says or else the teacher will mark him wrong. What kind of learning is that? Copy and paste? Okay, you might be smarter than most people your age (compared to say, the ones in international school - he goes to a local school) in terms of lots of knowledge - but as soon as I change the wording of a question (from the textbook) he would be like "Huh? I don't know! It's not even in the textbook!" And by the way, I am not blaming the students - I am blaming the teachers and education board in general.

Maybe I am expecting too much. But maybe I'm not. Education nowadays is getting worse, and creativity and thinking-out-of-the-box are deminishing. A lot.

No wonder why most children nowadays don't want to go to school.

Well, I guess this is where I come in. We'll see how things go.

Uneventful day?

2007-02-03T22:37:00.000+08:00

Today was supposed to an uneventful day. Nothing to do, nobody at home - brother's playing tennis then birthday party afterwards, my dad is also playing tennis with his friends, my mother's playing mahjong in her friend's house. Also, they will not be coming back home for dinner. So today was supposed to be all by myself. And that's supposed to be a good thing.

And I was planning to stay at home. Watching TV, taking a very very long bubble bath, whatever.

But then my neighbour, whose son I tutor, called me to go to her place to help her son with some homework. So I left home, sigh, but I thought to myself this should be quick. And sure it was quick.

Joyfully, I went back home. And then crap! I forgot to bring the keys! And usually there was somebody at home! But NOBODY this time! CRAP! I was at that moment the unluckiest person on earth! This unlocking-myself-out-of home-accidentally actually happened a few times. But come on - a weekend. For the whole day?!?

And.... well nothing good after that.

I walked around to pass time...

and froze to death.

Tennis + question

2007-01-28T21:02:00.000+08:00

Federer won again! What an inspirational game!

In the spirit of tennis, here's a question for you:

One thousand and twenty four tennis players compete in a singles competition (one player play against another - loser cannot play any further, winner stays in the game and play another winner, etc.). Assuming all players play, how many games are there until there is a champion?

Time and money

2007-01-15T19:39:00.000+08:00

I will probably settle with this watch from Ventura...

...since I don't have enough money to buy...

Actually, I don't even know how much the first watch costs, might not even afford it.

Ok, just checked the price for the first watch: $2000 US!! I can only wonder how much the Cartier costs. That's it! I will rely on the sun to keep track of time from now on!

Sigh... time > money

Gold is not forever with aqua regia

2007-01-09T15:25:00.000+08:00

Concentrated hydrochloric acid or nitric acid alone cannot dissolve gold.

Aqua regia, a mixture of hydrochloric acid and nitric acid, can dissolve gold because each of its two component acids carries out a different function. The nitric acid is a good oxidising agent. Chloride ions from the hydrochloric acid from coordination complexes with the gold ions, removing them from solution. Reducing the concentration of the Au3+ ions shifts the equilibrium towards the oxidised form.

Nitric acid/hydrochloric acid with gold on either side, aqua regia with gold in the centre

Au(s) + 3NO3-(aq) + 6H+(aq) ---> Au3+(aq) + 3NO2(g) + 3H2O(l)

Au3+ (aq) + 4Cl-(a) ---> AuCl4-(aq)

Don't start smoking, eat chocolate instead

2007-01-06T17:25:00.000+08:00

Thirty percent of men and 19 percent of women around the world smoke. One hundred thousand children under the age of 15 start smoking every day. One of every ten deaths around the world is caused by a smoking-related disease. With statistics like this, it's hard to imagine why smoking continues to be so widespread.

There are over 4,000 chemicals in a single cigarette, some of which are highly poisonous. Examples include naphthalene, which is used in moth repellent; acetone, the main component of nail polish remover; butane, a constituent of lighter fluid; and formaldehyde, used in embalming. Cigarettes also contain nicotine, a highly addictive stimulant that causes physical and psychological dependency.

The two most serious health effects of smoking are cancer and emphysema. Smoking has been linked to 11 forms of cancer, including cancer of the esophagus, mouth, pancreas, bladder, and kidney. According to recent studies, smokers are 26 times more likely to die of lung cancer than non-smokers. Emphysema is a chronic disease that destroys parts of the lungs and results in shortness of breath, hyperventilation, and asthma-like attacks.

Another common health effect of smoking is coronary artery disease. Smoking reduces the amount of oxygen that reaches the heart, increases blood clotting and blood pressure, and decreases high-density lipoprotein (HDL) or "good" cholesterol. Women taking oral contraceptives should not smoke, as the risk for stroke increases almost four times.

Other possible side effects of smoking include cataracts, reduced fertility, a higher risk of stroke, peptic ulcers, and back pain. Pregnant women who smoke are at risk for miscarriages, premature labor, and ectopic pregnancy. Babies born to mothers who smoke have a higher risk of sudden infant death syndrome (SIDS) and behavioral problems later in life.

Smoking has some unpleasant cosmetic effects too. Smokers often suffer from bad breath, yellowing teeth and nails, and early wrinkles around the mouth. Smoking causes changes in the coloring and texture of the skin, often resulting in an ashy complexion. A smoker is also three times more likely to lose teeth than a non-smoker.

Passive smoking, also known as second-hand smoke, can be just as deadly, especially for children, pregnant women, and non-smoking adults.

Nicotine: the chemical that makes smoking a choice of no return

Common name: nicotine | Chemical name: 1-methyl-2-(3-pyridyl)pyrrolidine | Molecular formula: C5H4NC4H7NCH3

Nicotine is a highly addictive substance that occurs naturally in tobacco. It is the active ingredient in tobacco smoke. It has a pungent odor and an acrid taste. Nicotine is defined as a poisonous, oily, pale yellow substance that turns brown upon exposure to air. In concentrated form, nicotine is used as a potent insecticide.

The amount of nicotine which occurs in tobacco leaves ranges from 2% to 7%.

Nicotine mimics the affects of acetylcholine (nerve signal transmitter) and it acts primarily on the autonomic nervous system. As such, it can be dangerous. Nicotine can cause respiratory failure and paralysis at doses of less than 50 mg. Smaller amounts can cause nausea, dizziness, lowered blood pressure, and heart palpitations.

A smoker inhales approximately 3g of nicotine per cigarette. Even this small amount constricts blood vessels, increases the heart rate, and acts on the central nervous system. It also confers a feeling of well-being and alertness on the smoker.

Nicotine itself is not considered carcinogenic. However, it is likely that it contributes to the increased incidence of heart disease in smokers. It may also enhance the growth of tumors caused by carcinogens.

People who use tobacco products in any form will develop a physiological addiction to nicotine. Proven to increase the flow of dopamine, a neurotransmitter, nicotine creates pleasurable feelings in the user, along with a desire to maintain them. When nicotine levels in the blood drop, smokers will develop withdrawal symptoms within 48 to 72 hours after the last cigarette. Withdrawal symptoms include anxiety, difficulty sleeping, irritability, heart rate and blood pressure changes, changes in brain waves, and sleeping problems.

The symptoms are so unpleasant that most smokers will resume smoking in an effort to raise nicotine levels in the blood to the point where the symptoms subside.

Many people try nicotine-containing chewing gums and adhesive skin patches in an effort to quit smoking. The rate of nicotine absorption is slower in these methods than it is with smoking and it does not provide the same pleasurable sensations; gums and patches, however, can help alleviate withdrawal symptoms.

It is important not to mix gums or patches with cigarettes, as this can lead to toxicity and nicotine overdose, which causes headache, palpitations, and nausea.

Other nicotine-delivery methods include nasal sprays and inhalers which more closely mimic the delivery and impact of nicotine as obtained by smoking.

Prolonged use of nicotine replacements, especially inhalers, is not recommended for more than a few months. Research has shown that extended use of these products could damage the cells lining the lungs and blood vessels.

I personally am not a smoker, and thankfully neither are my parents. But I know some classmates and friends who do smoke, which is a pity. Now they find it hard to quit. It really isn't a risk worth taking.

Now don't say I have not warned you!

For more exploration:

1. ONE
2. DEUX
3. DREI

Sources: wisegeek

Calories and so on

2007-01-05T14:58:00.000+08:00

How much is 200 calories actually? Well, it's about 800 joules. What is a joule?

As a rough guide, 1 joule is the amount of energy required to lift a one kilogram object up by a height of 10 centimetres on the surface of the Earth.

Or

The energy required to lift a small apple (102 g) one meter against Earth's gravity.

Or

In chemical energy stored in food.

Goodies: Celery (Apium graveolens dulce)
It is sometimes grouped as a low-calorie fibre bulk food. Not only does eating it will result in very few calories (actually negative, because digesting it requires more energy than the celery contains), it has a lot of vitamin C and fibre.

Baddies: Bacon (Sus scrofa domesticus)
Ewww.... I hate bacon. Not only does it tastes gross, it is full of fats: saturated, and worse unsaturated. Out of unsaturated fats, there are cis and trans fats (cis-trans or geometric isomerism - if you take chemistry).

cis

trans

Now it's the trans fats that we all talk about. Even your grandparents know what they are. Trans fats are bad for you! And indeed they are. It's all down to geometric isomerism. The C=C double bond in the trans isomer of the fat cause its rigidity and high density and make them hard to remove out of your body. I say they stay in your body forever (well a very long time)!

Anyways, some biology, some chemistry, some physics for you. What a happy post!

Foreign languages: oui or nein?

2007-01-03T19:27:00.000+08:00

When I started learning foreign languages (French and German), I loved it! I was young (about 10 years old) and I absorbed vocabulary fast. But as more complex grammar and vocabulary sunk in, and as there are more essay assignments, my love for language faded.

When I was fifteen or so, I attended language lessons solely because of exams. By then, I hated and dreaded language lessons!

As soon as I dropped languages at A-level, I was so relieved and happy! No more essays, stupid grammar, loads of vocabulary to learn, weird accents - extremely hard work really!

But unexpectedly, I kind of miss it now...

So, I am planning to brush up my foreign languages with the following podcasts. Feel free to do so too - these are for beginners. I will probably take up a foreign language at university too. I feel that knowing more languages open up so many more opportunities.

Podcasts
Deutsch (it's hilarious!): http://mygermanclass.com/
Français: http://frenchecole.libsyn.com/

Online dictionaries
Deutsch: LEO
Français: ARTFL

Exam frenzy

2007-01-02T20:42:00.000+08:00

What a lovely way to start the new year! Revision, revision, and more revision!

KEY:
Pink - revision
Red - actual exam

Happy New Year Everyone!

2007-01-01T00:00:00.000+08:00

Happy new year!

Fireworks | Laughter | Balloons | Champagne | Jumping people

We all deserve one!

Pushy alright

2006-12-25T14:06:00.000+08:00

This is hilar-ious!

Thank God my mum's not like that!

Hydrophobic

2006-12-21T22:52:00.001+08:00

This stuff and water really don't get along! Like me and horror movies!

Picnic geometry

2006-12-19T20:39:00.000+08:00

To pass time:

For more detailed instructions, click here.

Worst nightmare

2006-12-17T23:13:00.000+08:00

Clck to enlarge sketch:

Hope this will never happen!

Poisson distribution

2006-12-17T22:42:00.000+08:00

Get it?

Listening to...

2006-12-08T22:16:00.000+08:00

Beautiful World by Take That

Here standing in the rain
The sun has gone again and nothing's gonna change
Time, I need a little time as you slip out of sight
And nothing heals the pain.

And I know that it's you that's stopping me from falling
Crashing down, losing ground til I see you again
And you know...

The sun will shine, and we will see there's nothing standing in our way
Love will stand and never break
Never thought this could be me
Do you feel what I feel?
Everytime that you are near it's a beautiful world
A beautiful world

Words are hard to keep inside
Even though I've tried, impossible to hide.

And you know that it's me that's stopping you from falling
Crushing down, losing ground til I see you again
And you know...

The sun will shine, and we will see there's nothing standing in our way
Love will stand and never break
Never thought this could be me
Do you feel what I feel?
Everytime that you are near it's a beautiful world
A beautiful world

I'll be the stars guiding you
I'll be the place that you hide
I'd run a thousand miles, a thousand miles to be by your side.

You Are Loved (Don't Give Up) by Josh Groban

Don't give up
It's just the weight of the world
When your heart's heavy
I...I will lift it for you

Don't give up
Because you want to be heard
If silence keeps you
I...I will break it for you

Everybody wants to be understood
Well I can hear you
Everybody wants to be loved
Don't give up
Because you are loved

Don't give up
It's just the hurt that you hide
When you're lost inside
I...I will be there to find you

Don't give up
Because you want to burn bright
If darkness blinds you
I...I will shine to guide you

Everybody wants to be understood
Well I can hear you
Everybody wants to be loved
Don't give up
Because you are loved

You are loved
Don't give up
It's just the weight of the world
Don't give up
Every one is to be heard
You are loved

I Got Nerve by Miley Cyrus/Hannah Montana

We haven't met
And that's okay
Cause you will be askin' for me one day
Don't wanna wait
In line
The moment is mine, believe me
Don't close your eyes
Cause it's a chance worth takin'
And I think that I can shake you

I know where I stand
I know who I am I would never run away when life gets bad
It's everything I see, every part of me
Gonna get what I deserve
I got nerve

Electrified
I'm on a wire
Gettin' together and we're on fire
What I said
You heard
Now I got you spinnin'
Don't close your mind
The words I use are open
And I think that I can show you

I know where I stand I know who I am
I would never run away when life gets bad
It's everything I see, every part of me
I know I can change the world
I know what you like
I know what you think
Not afraid to stare you down until you blink
It's everything I see, every part of me
Gonna get what I deserve
I got nerve

You... you need to discover
Who can make you feel free
And I... I need to uncover
The part of you that's reaching out for me

Hey!

I know where I stand I know who I am
I would never run away when life gets bad...
It's everthing I see every part of me
I know I can change the world
I know what your like
I know what you think
Not afraid to stare you down until you blink
It's everthing I see, every part of me
Gonna get what I deserve
I got nerve

I'm what you want, I'm what you need, I'm what you want, I'm what you need...

I know what your like
I know what you think
Not afraid to stare you down until you blink
It's everthing I see every part of me
Gonna get what I deserve I got... I GOT NERVE!

Heroes again!

2006-12-06T23:46:00.001+08:00

This show just gets better and better. I am speechless.

And yes, it's even better than parabolas!

I absolutely cannot wait until January 22, 2007! Proof: this show almost made me forget about Oxford's reply, which will be in less than eight days! Ahh... adrenaline rush!

Parabolas

2006-12-06T17:27:00.000+08:00

What is a parabola? How is it defined?

What is the standard parabola equation? Most people I ask would say y = x^2. Wrong!

Before I get into the mathematics of this, imagine a point and a line. Draw a locus which is equidistant (equally distant) from the point and the line, and voila you get a parabola! That point is known as the focus of the parabola, and the line, directrix. This property is often called the focus-directrix property of the parabola.

Imagine a parabola which opens to the right and has its vertex at (0,0). Let the focus of the parabola be the point (a, 0), and the directrix the equation x + a = 0. Since the distance of the line from the directrix to the parabola is equal to the distance from the focus to the parabola, then

√[(x - a)^2 - y^2] = x + a

Squaring both sides,

(x - a)^2 - y^2 = (x + a)^2

x^2 - 2ax + a^2 - y^2 = x^2 + 2ax + a^2

y^2 = 4ax --- this is the cartesian equation of the parabola.

x = at^2, y = 2at --- these are the parametric equation of the parabola.

Using implicit differentiation and simple coordinate geometry, you can work out the tangent of the parabola at any point.

An exercise for you:
Find an equation of the normal at P(4t, 4t^2) on the parabola with equation 4y = x^2. The normal meets the y-axis at the point Q. Find, in cartesian form, an equation of the locus of the point M, the mid-point of PQ, as t varies.

Loving further maths!

A reminder of how infinitesimal we are

2006-12-05T18:18:00.001+08:00

The observable universe is 78 billion light years in diameter...

Don't fear if you feel lonely. We will find another civilisation in this universe... someday.

Christmas gift?

2006-12-04T17:42:00.000+08:00

I really want this set of earphones for Christmas!

"Ergonomic and lightweight sound isolating earphones offer the most accurate audio reproduction from both portable and home stereo audio sources—for the ultimate in precision highs and rich low end..."

But it's more expensive than the iPod!

Heroes - the beginning of hope...

2006-11-29T22:40:00.001+08:00

NBC's "Heroes" takes my breath away! The pilot episode got me hooked and subsequent episodes got me loving the show exponentially! The storyline and acting are flawless. Full of suspense, excitment, and surprise in each episode. This is definitely a one-in-a-million show!

"As a total eclipse casts its shadow across the globe, a genetics professor in India is led by father's disappearance to uncover a secret theory - there are people with super powers living among us. A young dreamer tries to convince his politician brother that he can fly. A high school cheerleader learns that she is totally indestructible. A Las Vegas stripper, struggling to make ends meet to support her young son, discovers that her mirror image has a secret. A fugitive from justice continues to baffle authorities who twice have been unable to contain him. A gifted artist, whose drug addiction is destroying his life and relationship with his girlfriend, can paint the future. A down-on-his-luck Los Angeles beat cop can hear people's thoughts, which puts him on the trail of an elusive serial killer. In Japan, a young man develops a way to stop time through sheer will power. Their ultimate destiny is nothing less than saving the world…"

Official website: http://www.nbc.com/Heroes
Official fansite: http://www.9thwonders.com
Producer's blog: http://gregbeeman.blogspot.com
Podcast: http://www.thetenthwonder.com

EDTA: Part 1

2006-11-22T20:21:00.000+08:00

Unwanted metals often find their way into food from the soil and from machinery during harveting and processing. Often these metals, such as copper, iron and nickel, then degrade the food stuffs by catalyzing the oxidation of the fats in the food. A class of food additives known as sequestrants can be added to food. The additive reacts with trace metals in foods, forming tightly bound complexes (sequestered - withdrew from use), thereby preventing the decompostion of the food.

The sodium and calcium salts of EDTA (ethylenediaminetetraacetic acid) are common sequestrants in many kinds of foods and beverages.

EDTA (ethylenediaminetetraacetic acid). The EDTA molecule can bind to metal ions by forming six bonds to it - two from nitrogen atoms in amino groups and four from oxygen atoms in carboxyl groups.

Lead poisoning is hence treated with EDTA, but of course the downside of it is calcium ions and other essential metal ions are drained as well.

To be continued...

Sources: www.3dchem.com

The last one

2006-11-21T23:04:00.000+08:00

I got all my university offers now, but one...

The most anticipated one...

Impatiently, anxiously, waiting for Oxford's reply...

December 15th...

Not in the mood to write anything productive. But if you are bored, check out "Phd comics" (stuck on the right column ) - an extremely exaggerated chronicle of university life - or not?

Hello today!

2006-11-20T18:53:00.000+08:00

Hi! Welcome to my fresh new blog!

You can visit my old blog here.

In this blog, I'm planning to record my experiences at a university in a country called United Kingdom. (Ok... I sound like an alien who just landed on Earth.) And in between these experiences, I will add whatever that catches my attention.

But right now, I'm in a thick mist of uncertainty because:

(a) I don't know which university yet. (I'm in my last year of secondary education, in the midst of the UCAS application process and A-level exams.)

(b) I've only been to United Kingdom twice, and there's no one I know there. (Strictly, not true, but true enough.)

(c) Global disasters

(d) World War III

(e) Avian flu outbreak

The list goes on forever.

Hopefully, I'll make it.