Thursday 15 December 2016

Petroleum: From Beneath Our Feet To Fuelling Our Lives

Take a pen and drop it on the floor. Now drop the same pen onto a table. Does it sound the same or different? Different things make different noises when you hit them. But how does this relate to petroleum exploration?

To find petroleum, noise has to go down through layers of different rocks. Therefore, we need to find out what noise petroleum makes and how it differs from all the other types of rocks that exist in those layers.

On land, geologists look for petroleum by noise from setting off an explosion. Then, they will analyse the different routes of which the noise ‘echoed’. From the data, geologists can decide what types of rocks are under the ground. 

Meanwhile, to look for petroleum at sea, geologists will ‘shoot’ air at a very high pressure at the sea bed. The rocks underneath will ‘echo’ and the result is similar. 

When the rocks are found to have petroleum in them, geologists will drill a hole to harvest them. However, it is quite challenging to drill a hole under the sea. There are places where it is very deep and rough. Even when you drill using a ship, it is hard to get it to stay in one place. In the early days, scientists and engineers designed a ‘fixed platform’. Gradually, they innovate this idea with a ship in mind. The results are platforms which float but stay in one place. 

The next step is to get the petroleum or gas from where they are found to where we want it. How do we move a liquid or a gas? Think of getting a glass of water. If your source is a tap or a well, you would need a pipe to bring the water to where you can reach it. Then you need a glass or container to take the water from where you can reach it to where you can drink it. It is similar with petroleum. There are thousands of kilometres of pipes pumping petroleum down under. Huge ships and tankers, transport the petroleum and gas around the world. 

Our modern way of life has grown to become very dependent on the petroleum industry. Look around us; the vehicle that we drive or ride on, the road that it drives on, the clothes and shoes we wear, make-up, paint, fertilizers and many more things that we can possibly think of. Amazingly, more than 3,000 products that exist now are made possible by petroleum and gas.

Check out more fun and interactive story of science and technology of the petroleum industry at Petrosains the Discovery Centre!  

Shared by Nor Azhar Ishak
Guest Blogger

Wednesday 14 December 2016

Do You Know Your Sushi?

Mention sushi and you’ll visualize a slice of mouth-watering raw salmon placed delicately on a small clump of rice.  Oops…maybe that’s not sushi, could it be sashimi or nigiri or…?

For the uninitiated or confused, sashimi is fresh, raw seafood sliced into thin & small pieces. Each slice is then dipped in soy sauce with wasabi paste before it is popped into your mouth!

Sushi on the other hand is vinegared rice served with a variety of toppings, not necessarily just raw fish. Do bear in mind there are many types of sushi.  Some of the popular ones are: 

Nigiri [nigirizushi]

Oblong mound of vinegared rice with fish, shellfish, etc. on top. 
Countless varieties of nigirizushi - most common are tuna, shrimp, eel, squid, octopus & fried egg.

How to eat it
Place nigiri between your thumb & fore/index fingers, turn it upside down, & dip the topping in the soy sauce. 
Done this way because dipping rice-side first will cause it to fall apart. 
Place it in your mouth fish side down.

Maki rolls [makizushi]

Cylindrical pieces of vinegared rice & other ingredients (thin slices of cucumber, soy paper, or thin omelette skin) wrapped in nori (seaweed sheets). 
Made by rolling ingredients with a bamboo sushi mat & then slicing the pipe-shaped roll into cylindrical pieces.

How to eat it
Eaten with your fingers. 
When rice is on the outside, this is called uramaki.

Temaki [temakizushi]

Rolled cone of seaweed, wrapped around rice and fillings.
How to eat it
Eaten from the hand.
Eat right away after it is made while the nori is still crispy.
Dip in the soy sauce with rice/ingredients from the top, or pour soy sauce slowly from the top.
Eat from the top with several bites.

Chirashi [chirashisushi]

Dish of seafood, mushrooms & vegetables spread over sushi rice. 
Resemble seafood domburi, the difference is chirashizushi uses sushi rice while domburi uses regular, unseasoned rice.

How to eat it
Eaten with chopsticks.
Eat the pieces one by one.
Don't pour soy sauce over the rice.

SUSHI RICE | How is it prepared?

It’s important the right type of rice is used otherwise the grains won’t stick together & hold its shape.  Imagine nigirizushi falling apart when you pick it up with your fingers! We don’t want that!

First of all, the rice must be the short-grain variety – round & with a length about the same as the width. Technique of cooking sushi rice differs slightly from ordinary rice, most of us might find it complicated.  
[Refer to this link: if you’ll like to give it a try.]

What’s the purpose of sushi vinegar?
The all-important reason for adding sushi vinegar is because sushi rice requires a vinegary solution so that the pH can be lowered to 4.1 in order to kill microbes for safe consumption. In addition to that, it also adds flavour to sushi rice.  

If sushi vinegar is not available, it could be replaced with rice vinegar.  However it will taste flat as it lacks the seasoning of salt & sugar. 

FISH | How safe is it for consumption?

Fresh fish is ALWAYS used for sushi and it MUST be frozen when bought. Freezing has to take place quickly so that the ice crystals formed are very short & don't pierce through cell walls.

If freezing is not done properly, some fish that may contain anisaris, a parasitic worm, may cause severe harm to humans.  Anisaris generally tends to infest:

Swordfish          Tuna          Sardines          Hake          Cod          Haddock

Monkfish          Scabbered fish

The good news is it dies at temperatures above 65 °C or below -20 °C. So, after freezing for at least 96 hours, the fish can be transferred to the fridge to defrost, but not completely. After a few hours in the fridge, the fish can be taken out to be cut then put back to finish defrosting.

Enjoy your sushi!

Shared by Azni Zainal Abidin
Guest Blogger

Aktiviti #3 Kegemaran Saya Di Petrosains

Hai! Nama saya Fizz. Saya adalah salah seorang Komunikator Sains di Petrosains. Ada 'baaaanyaaaaak' aktiviti sains yang saya gemari di sini. Salah satu aktiviti sains yang paling saya gemari di Petrosains dan mengungguli tempat ketiga dalam carta persendirian saya adalah “Rude Noise Machine”. Nak tau #1 & #2, kenalah tunggu pos saya yang seterusnya.
Jadi, kenapa saya suka aktiviti “Rude Noise Machine” ini?

Sebabnya ialah ia lain dari yang lain. Ia sebenarnya adalah satu alat yang boleh mengeluarkan bunyi seperti….   bunyi kentut. Tak percaya? Kalau tak percaya, jom cuba. Kalau percaya pun, jomlah cuba juga!

Apa yang anda perlukan:

a) Suratkhabar lama
b) Pensel
c) Gunting
d) Pita pelekat 

Cara-cara membuatnya:

1. Potong kertas pada saiz yang bersesuaian (1/4 saiz suratkhabar)

2. Gulung kertas. Gunakan pensel untuk memudahkan permulaan gulungan. (Pastikan pensel tidak tertinggal di dalam gulungan!)

3. Potong salah satu hujung gulungan supaya menjadi tajam.

4. Pegang gulungan seperti gambar di bawah dan potong dari bahagian yang ditunjukkan.

5. Potong sehingga tinggal kira-kira 0.5 cm bahagian sahaja yang bersambung.

6. Anda akan dapati terdapat beberapa helai kepingan berbentuk segitiga. Potong semuanya dan tinggalkan satu keping sahaja. (Sekiranya terdapat beberapa helai kepingan segitiga, ia akan sukar untuk bergetar dan menjadikannya sukar berbunyi).

7. Lipat sedikit bahagian segitiga seperti gambar dibawah.

8. Akhir sekali, sedut perlahan-lahan dari hujung gulungan kertas seperti anda menggunakan penyedut minuman. 

9. Adakah anda berjaya menghasilkan bunyi dengan alat ini?

10. Adakah bunyi yang dihasilkan berbeza jika gulungan kertas lebih pendek?
Apakah bunyi? Bunyi terhasil daripada getaran. Getaran tersebut akan menyebabkan medium (udara, air dan pepejal) di sekelilingnya juga bergetar. Getaran yang sampai ke gegendang telinga kita akan dihantar ke otak untuk ditafsirkan. 

Dalam aktiviti ini, apabila udara disedut melalui gulungan kertas, kepingan segitiga di hujung gulungan akan bergetar dan menghasilkan bunyi.

Selamat mencuba!

Shared by Fizz Tahir
Guest Blogger

Tuesday 13 December 2016

Bagaimana Nasi Kerabu Mendapat Warna Biru?

Nasi kerabu merupakan hidangan popular yang berasal dari negeri Kelantan. Pada kebiasaannya ia dihidangkan bersama sambal tumis, kerisik (sambal) ikan, ulam-ulaman, lada solok, telur asin, ikan celup tepung, daging bakar dan ayam percik. Oh! Jangan lupa keropok, budu dan air sirap ais! Lazatkan? 

Saya terpanggil untuk menghasilkan sebuah dokumentasi perkongsian ringkas mengenai warna biru pada nasi kerabu seusai sambutan iftar keluarga baru-baru ini. Anak sayalah yang bertanyakan soalan cepu emas ini. Jom kita kupas jawapannya satu persatu. 

Pertama sekali, ingin saya memperkenalkan sejenis bunga yang bertanggungjawab ke atas persoalan ini. Bunga nasi kerabu berwarna biru nila (indigo), yang dikenali juga sebagai bunga Telang berasal dari spesis pokok kekacang yang hidup memanjat. Bunganya menjadi pewarna makanan popular sejak zaman dahulu lagi.

Ringkasan taksonomi bunga Telang

Jadi, bagaimana caranya untuk menghasilkan pewarna nasi kerabu? Saya memetik beberapa kuntum bunga Telang dari halaman ibu untuk tujuan perkongsian ini. Bunga tersebut direndam dalam secawan air suam (tidak terlalu panas supaya ia tidak kehilangan khasiatnya). Air biru nila yang terhasil di gunakan untuk memasak nasi kerabu. Sudah pasti bahan lain sebagai pembangkit aroma nasi seperti serai, daun lima purut dan daun pandan ditambah bersama beras tadi. Masak nasi seperti biasa dan anda akan dapati warna nasi anda berwarna biru!

Anthocyanin (Antosianin) adalah sebatian kimia semulajadi yang memberi pigmen biru pada bunga Telang. Antosianin juga boleh didapati pada buah-buahan seperti beri dan buah senduduk, bunga seri pagi dan sayur-sayuran seperti kobis merah (red cabbage) dan terung. Sebatian kimia ini tidak berbahaya malah dipercayai boleh menjadi agen awet muda! Selain daripada digunakan sebagai pewarna makanan untuk nasi kerabu dan kuih-muih, ia juga digunakan dengan meluas sebagai nila atau pewarna fabrik semulajadi. 

Mahu cuba ekperimen lain menggunakan pewarna anthocyanin ini? Ini petunjuknya… Anthocyanin sebenarnya penunjuk pH semulajadi. Ia boleh digunakan untuk menguji keasidan atau kealkalian sesuatu larutan. Sebagai contoh, jika anda menitiskan sedikit air sabun, larutan biru “berantosianin” (dari rendaman bunga Telang) akan bertukar daripada warna biru kepada warna biru kehijauan. Apa lagi? Cubalah uji larutan atau cecair yang anda boleh perolehi di sekitar dan dalam rumah seperti pencuci lantai, syampu, cuka dan air paip. Lihat perubahan warna pada ditunjukkan oleh larutan ajaib (rendaman bunga Telang) itu dan beritahu kami!

Shared by Izhana
Guest Blogger

Wednesday 7 December 2016

Do You Know Your Space Rocks?

Meteoroids are bits of space rock or metal that have broken off asteroids and comet. If meteoroids falls through the Earth’s atmosphere, it’s called a meteor. If the meteor hits the Earth’s surface it’s called a meteorite.

Shared by Nor Azhar Ishak
Guest Blogger